Research activity information

• Oct. 2022 The 12th IEEE Symposium on Large Data Analysis and Visualization (LDAV2022), Honorable Mention Award, Angular-based Edge Bundled Parallel Coordinates Plot for the Visual Analysis of Large Ensemble Simulation Data

  Keita Watanabe, Naohisa Sakamoto, Jorji Nonaka, Yasumitsu Maejima


• Apr. 2022 The 15th IEEE Pacific Visualization Symposium, Best Paper Honorable Mention, A Visual Analytics Approach for Hardware System Monitoring with Streaming Functional Data Analysis

  Shilpika, Takanori Fujiwara, Naohisa Sakamoto, Jorji Nonaka, Kwan-Liu Ma


• Feb. 2022 第５回ビジュアリゼーションワークショップ（可視化情報学会）, 優秀ポスター賞, 情報エントロピーに基づく in-situ 可視化向け最適視点移動経路推定法

  岩田 憲, 坂本 尚久, 野中 丈士


• Nov. 2018 Asia Simulation Conference 2018, Best Paper Award Nominated, A Transfer Entropy based Visual Analytics System for Identifying Causality of Critical Hardware Failures - Case Study: CPU Failures in the K Computer

  Kazuki Koiso, Naohisa Sakamoto, Jorji Nonaka, Fumiyoshi Shoji


• Apr. 2018 IEEE Pacific Visualization, Honorable Mention Poster Award, A Fully Parallel Particle-based Volume Rendering for Large-Scale Unstructured Volume Datasets

  Kengo Hayashi, Yoshiaki Yamaoka, SAKAMOTO NAOHISA, Jorji Nonaka

  International society


• Sep. 2016 Japan Society of Simulation Technology, Japan Society of Simulation Technology Award - Encouragement Award, Network Coarse-Graining for Evaluation Structures

  Yosuke Onoue, Nobuyuki Kukimoto, SAKAMOTO NAOHISA, Koji Koyamada

  Official journal


• Jul. 2014 The Visualization Society of Japan, The Visualization Society of Japan Award (The 25th period) - Technical Award, High-quality Particle-based Volume Rendering for Large-scale Unstructured Volume Datasets

  SAKAMOTO NAOHISA, Naoya Maeda, Takuma Kawamura, Koji Koyamada

  Official journal


• Nov. 2012 Asia Simulation Conference, Best Paper Award Nominated, Extraction of Vortices and Exploration of the Ocean Data by Visualization System

  Chi Zhang, SAKAMOTO NAOHISA, Koji Koyamada

  International society


• Mar. 2012 IEEE Pacific Visualization, Best Poster Award, Stochastic Approach for Integrated Rendering of Volumes and Semi-transparent polygons on a High-resolution Display System

  SAKAMOTO NAOHISA, Jun Nishimura, Koji Koyamada

  International society


• Nov. 2011 Asia Simulation Conference 2011, Outstanding Paper Award, Clustered Parallel Coordinates with High-Speed k-Means Algorithm and Out-of-Core Feature

  Chi Zhang, Naohisa Sakamoto, Koji Koyamada


• Oct. 2009 The Visualization Society of Japan, Best Paper Award (The 21th period), 粒子ベースボリュームレンダリングのための粒子密度推定法 -大規模非構造ボリュームデータに対する適用-

  河村拓馬, 坂本尚久


• Oct. 2009 Asia Simulation Conference 2009, Best Poster Award, Spatio-Temporal Analysis of Time-Varying Multivariate Volume Dataset Using Volumetric Parallel Coordinates

  Shiori Yasuoka, Naohisa Sakamoto, Koji Koyamada


• Mar. 2008 IEEE Pacific Visualization Symposium 2008, Best Poster Award, Multi-Volume Rendering Using Particle Fusion

  Naohisa Sakamoto, Koji Koyamada, Ayumu Saito, Akinori Kimura, Satoshi Tanaka


• Jul. 2007 The Visualization Society of Japan, Technical Award (The 18th period), Data Reduction by Applying and Image-Based Modeling and Rendering Technique to CG Models

  Hideo Miyachi, Naohisa Sakamoto

• Caspase-mediated cleavage of a scaffold protein, MPRIP, yields a truncated form that is involved in repetitive bleb formation

  Kazuhiro Sakamaki, Naohisa Sakamoto, Yuki Tsujimura, Takahiro Iwasaki, Takuma Kawamura, Jun Nakabayashi, Rhea S. D'Souza, Arooma Jannat, Ken-ichiro Takeshima, Hiroyuki Takeda, Koji Koyamada, Hideo Yokota

  Jan. 2025, FEBS JOURNAL, English

  Scientific journal


• Edge highlighting with depth-dependent opacity gradation of laser-scanned point clouds improves the accuracy of perceived depth in transparent multi-view 3D visualizations

  Daimon Aoi, Kyoko Hasegawa, Liang Li, Yuichi Sakano, Naohisa Sakamoto, Satoshi Takatori, Satoshi Tanaka

  Dec. 2024, JOURNAL OF VISUALIZATION, 27(6) (6), 1103 - 1115, English

  Scientific journal


• Edge highlighting of laser-scanned point clouds improves the accuracy of perceived depth in transparent multi-view 3D visualizations

  Daimon Aoi, Kyoko Hasegawa, Liang Li, Yuichi Sakano, Naohisa Sakamoto, Satoshi Tanaka

  Feb. 2024, International Journal of Modeling, Simulation, and Scientific Computing, 15(1) (1), 2450021 - 19, English

  Scientific journal


• Enhanced Simulation and Analysis of Air Pollutants Using Multi-Platform HPC and In-Situ Visualization

  Chongke Bi, Fumiyoshi Shoji, Kenji Ono, Naohisa Sakamoto, Jorji Nonaka, Honggang Yin, Wenjuan Cui

  2024, 2024 IEEE INTERNATIONAL CONFERENCE ON CLUSTER COMPUTING WORKSHOPS, CLUSTER WORKSHOPS 2024, 200 - 201, English

  International conference proceedings


• On the Building of a Common In-Situ Visualization Environment for Arm A64FX Supercomputers

  Jorji Nonaka, Masahiro Nakao, Hitoshi Murai, Keiji Yamamoto, Masaaki Terai, Tomohiro Kawanabe, Toshihiko Kai, Fumiyoshi Shoji, Daichi Obinata, Hiroyuki Ito, Shunji Uno, Takanori Haga, Manabu Motokawa, Atsushi Fujino, Naoyuki Fujita, Seiji Tsutsumi, Atsushi Toyoda, Naohisa Sakamoto

  2024, Proceedings - 2024 IEEE International Conference on Cluster Computing Workshops, CLUSTER Workshops 2024, 202 - 203, English

  International conference proceedings


• A Learning Acceleration of Image-based Surrogate Models Using Pixel Shuffling

  Miyake Tomoya, Tanaka Yuki, Sakamoto Naohisa

  Research on surrogate models, which are expected to significantly reduce computational time by replacing large-scale numerical simulations that require a large amount of computational time with approximate models such as machine learning models, has been attracting attention. However, if the numerical data generated by the simulations is large, the data generated by the surrogate model will also be large, which may cause time consuming in visualization processing during analysis. If a surrogate model, which we call image-based surrogate model, that also takes visualization processing into consideration can be constructed for large-scale simulation results, it will be possible to directly generate visualization results without simulation data, which is expected to greatly improve efficiency in analysis through visualization. In this study, an image-based surrogate model is constructed by learning multiple visualization images of numerical data and the simulation parameters at that time. The learning model to be developed is constructed based on the adversarial generative network model, and pixel shuffling is applied to the generators that are part of the model to make feature extraction more efficient, thereby speeding up the convergence of learning loss. In our experiments, we applied this method to actual numerical simulations and succeeded in speeding up the process by a factor of approximately 2.7 while maintaining the same level of prediction accuracy as existing learning models.

  Japan Society for Simulation Technology, 2024, Transaction of the Japan Society for Simulation Technology, 16(2) (2), 48 - 59, Japanese


• Information Entropy-based Camera Focus Point and Zoom Level Adjustment for Smart In-Situ Visualization.

  Taisei Matsushima, Ken Iwata, Naohisa Sakamoto, Jorji Nonaka, Chongke Bi

  2024, HPC Asia, 164 - 173, English

  International conference proceedings


• Analysis Towards Energy-Aware Image-based In Situ Visualization on the Fugaku.

  Razil Tahir, Jorji Nonaka, Ken Iwata, Taisei Matsushima, Naohisa Sakamoto, Chongke Bi, Masahiro Nakao, Hitoshi Murai

  2024, HPC Asia, 154 - 163, English

  International conference proceedings


• Flow Field Feature Extraction and Tracking Based on Spatial Similarity Metrics

  Peiru Pan, Chongke Bi, Jizeng Wei, Naohisa Sakamoto, Jorji Nonaka

  Jun. 2023, NICOGRAPH International 2023, 30 - 37, English

  [Refereed]

  International conference proceedings


• Reflections on the Developments of Visual Analytics Systems for the K Computer System Log Data

  Jorji Nonaka, Keijiro Fujita, Takanori Fujiwara, Naohisa Sakamoto, Keiji Yamamoto, Masaaki Terai, Toshiyuki Tsukamoto, Fumiyoshi Shoji

  Jun. 2023, The Gap between Visualization Research and Visualization Software (VisGap 2023), NA, 11 - 18, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• VR Extension of Client Server Type Particle-based Volume Visualization Application

  Takuma Kawamura, Naohisa Sakamoto, Tsukasa Osaki

  2023, Journal of Advanced Simulation in Science and Engineering, 10(1) (1), 31 - 39, English

  Scientific journal


• Information Entropy-based Camera Path Estimation for In-Situ Visualization.

  Ken Iwata, Naohisa Sakamoto, Jorji Nonaka, Chongke Bi

  In-situ processing has widely been recognized as an effective approach for the visualization and analysis of large-scale simulation outputs from modern HPC systems. One of the most common approaches for batch-based in-situ visualization is the image- or video-based approach. In this kind of approach, a large number of rendered images are generated from different viewpoints at each time step and has proven useful for detailed analysis of the main simulation results. However, during test runs and model calibration runs before the main simulation run, a quick overview might be sufficient and useful. In this work, we focused on selecting the viewpoints which provide as much information as possible by using information entropy to maximize the subsequent visual analysis task. However, by simply following the selected viewpoints at each of the visualization time steps will probably lead to a rapidly changing video, which can impact the understanding. Therefore, we have also worked on an efficient camera path estimation approach for connecting selected viewpoints, at regular intervals, to generate a smooth video. This resulting video is expected to assist in rapid understanding of the underlying simulation phenomena and can be helpful to narrow down the temporal region of interest to minimize the turnaround time during detailed visual exploration via image- or video-based visual analysis of the main simulation run. We implemented and evaluated the proposed approach using the OpenFOAM CFD application, on an x86-based Server and an ARM A64FX-based supercomputer (Fugaku), and we obtained positive evaluations from domain scientists.

  2023, CoRR, abs/2301.11591


• VR Extension of Particle-based Remote Visualization Application

  Takuma Kawamura, Naohisa Sakamoto

  Sep. 2022, The 41st JSST Annual International Conference on Simulation Technology (JSST2022), -, 266 - 269, English

  [Refereed]

  Scientific journal


• Angular-based Edge Bundled Parallel Coordinates Plot for the Visual Analysis of Large Ensemble Simulation Data.

  Keita Watanabe, Naohisa Sakamoto, Jorji Nonaka, Yasumitsu Maejima

  IEEE, 2022, 12th IEEE Symposium on Large Data Analysis and Visualization(LDAV), 1 - 10

  International conference proceedings


• Improving Depth Perception Using Edge Highlighting in Transparent Stereoscopic Visualizations of Laser-Scanned 3D Point Clouds.

  Daimon Aoi, Kyoko Hasegawa, Liang Li 0002, Yuichi Sakano, Naohisa Sakamoto, Satoshi Tanaka

  Springer, 2022, Methods and Applications for Modeling and Simulation of Complex Systems - 21st Asia Simulation Conference, 622 - 631

  International conference proceedings


• A Visual Analytics Method for Time-Series Log Data Using Multiple Dimensionality Reduction

  Keijiro Fujita, Naohisa Sakamoto, Takanori Fujiwara, Toshiyuki Tsukamoto, Jorji Nonaka

  2022, JOURNAL OF ADVANCED SIMULATION IN SCIENCE AND ENGINEERING, 9(2) (2), 206 - 219, English

  Scientific journal


• Angular-based Edge Bundled Parallel Coordinates Plot for the Visual Analysis of Large Ensemble Simulation Data.

  Keita Watanabe, Naohisa Sakamoto, Jorji Nonaka, Yasumitsu Maejima

  2022, The 12th IEEE Symposium on Large Data Analysis and Visualization (LDAV2022), abs/2209.10874, 43 - 52, English

  [Refereed]

  International conference proceedings


• A Visual Analytics Approach for Hardware System Monitoring with Streaming Functional Data Analysis.

  Shilpika, Takanori Fujiwara, Naohisa Sakamoto, Jorji Nonaka, Kwan-Liu Ma

  2022, IEEE Transactions on Visualization and Computer Graphics, 28(6) (6), 2338 - 2349, English, International magazine

  Scientific journal


• A Visual Analytics Framework for Reviewing Multivariate Time-Series Data with Dimensionality Reduction.

  Takanori Fujiwara, Shilpika, Naohisa Sakamoto, Jorji Nonaka, Keiji Yamamoto, Kwan-Liu Ma

  Feb. 2021, IEEE transactions on visualization and computer graphics, 27(2) (2), 1601 - 1611, English, International magazine

  [Refereed]

  Scientific journal


• A Visual Analytics Framework for Reviewing Multivariate Time-Series Data with Dimensionality Reduction.

  Takanori Fujiwara, Shilpika, Naohisa Sakamoto, Jorji Nonaka, Keiji Yamamoto, Kwan-Liu Ma

  Data-driven problem solving in many real-world applications involves analysis of time-dependent multivariate data, for which dimensionality reduction (DR) methods are often used to uncover the intrinsic structure and features of the data. However, DR is usually applied to a subset of data that is either single-time-point multivariate or univariate time-series, resulting in the need to manually examine and correlate the DR results out of different data subsets. When the number of dimensions is large either in terms of the number of time points or attributes, this manual task becomes too tedious and infeasible. In this paper, we present MulTiDR, a new DR framework that enables processing of time-dependent multivariate data as a whole to provide a comprehensive overview of the data. With the framework, we employ DR in two steps. When treating the instances, time points, and attributes of the data as a 3D array, the first DR step reduces the three axes of the array to two, and the second DR step visualizes the data in a lower-dimensional space. In addition, by coupling with a contrastive learning method and interactive visualizations, our framework enhances analysts' ability to interpret DR results. We demonstrate the effectiveness of our framework with four case studies using real-world datasets.

  2021, IEEE Trans. Vis. Comput. Graph., 27(2) (2), 1601 - 1611


• Interactive Exploration of the In-Situ Visualization of a Magnetohydrodynamic Simulation

  Akira KAGEYAMA, Naohisa SAKAMOTO, Hideaki MIURA, Nobuaki OHNO

  Sep. 2020, Plasma and Fusion Research, 15(0) (0), 1401065 - 1401065, English

  Scientific journal


• 4次元ストリートビュー:計算機シミュレーションの新しい可視化法

  陰山 聡, 坂本 尚久, 大野 暢亮

  プラズマ・核融合学会編集委員会, Apr. 2020, プラズマ・核融合学会誌, 96(4) (4), 199 - 206, Japanese

  [Refereed]


• A Visual Analytics Approach to Monitor Time-Series Data with Incremental and Progressive Functional Data Analysis.

  Shilpika, Takanori Fujiwara, Naohisa Sakamoto, Jorji Nonaka, Kwan-Liu Ma

  2020, CoRR, abs/2011.13079

  Scientific journal


• 4D street view: a video-based visualization method.

  Akira Kageyama, Naohisa Sakamoto

  2020, PeerJ Comput. Sci., 6, e305 - 305, English, International magazine

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Lessons Learned from Large Data Visualization Software Development for the K computer.

  Jorji Nonaka, Naohisa Sakamoto

  High Performance Computing (HPC) always had a close relationship with visualization as we can remember the landmark report on ''Visualization in Scientific Computing'', which was credited to have coined the term Scientific Visualization (SciVis). K computer, a Japanese flagship HPC system, appeared in 2011 as the most powerful supercomputer in the Top500 list, and as other similar HPC systems in that ranking, it was designed to enable ''Grand Challenge'' scientific computing with unprecedented scale and size. RIKEN Center for Computational Science (RIKEN R-CCS) operated and provided the K computer's computational resources to the HPC community for almost 8 years until it was decommissioned in 2019. Considering that most of the scientific computing results were publicly presented in the form of visual images and movies, we can infer that the SciVis was widely applied for assisting the domain scientists with their end-to-end scientific computing workflows. In addition to the traditional visualization applications, various others large data visualization software development were conducted in order to tackle the increased size and amount of the simulation outputs. RIKEN R-CCS participated in some of these development and deployment dealing with several environmental and human factors. Although we have no precise statistics regarding the visualization software usage, in this paper, we would like to present some findings and lessons learned from the large data visualization software development in the K computer environment.

  Eurographics Association, 2020, 1st Workshop on the Gap between Visualization Research and Visualization Software(VisGap@Eurographics/EuroVis), 77 - 81, English

  [Refereed]

  International conference proceedings

  Link to Kobe Univ. Repository (Kernel)


• YYZVis: An Efficient Visualization Toolkit for Yin-Yang-Zhong Grid Dataset

  Kaoru Uemori, Naohisa Sakamoto, Nobuaki Ohno, Akira Kageyama

  2020, Journal of Advanced Simulation in Science and Engineering, 7(1) (1), 15 - 33, English

  [Refereed]

  Scientific journal


• An Interactive Visualization Toolkit for Yin-Yang-Zhong Grid Dataset

  Kaoru Uemori, Naohisa Sakamoto, Nobuaki Ohno, Akira Kageyama

  Nov. 2019, The 38th JSST Annual International Conference on Simulation Technology (JSST2019), 27 - 30, English

  [Refereed]

  International conference proceedings


• A View from the Facility Operations Side on the Long-Term Operation of the K Computer System

  Jorji Nonaka, Keiji Yamamoto, Akiyoshi Kuroda, Toshiyuki Tsukamoto, Kazuki Koiso, Naohisa Sakamoto

  Nov. 2019, The 2019 Conference on Supercomputing (SC19), Research Poster, English

  [Refereed]

  International conference proceedings


• A comparison of order-independent techniques for intersecting iso-surfaces with transparency

  Yu Long, Koji Koyamada, Naohisa Sakamoto

  Sep. 2019, The 15th Asia Symposium on Visualization (ASV15), English

  [Refereed]

  Symposium


• Ambient Occulusion for Semi-transparent Streamlines with Stochastic Rendering Technique

  Yasuyuki Fujita, Naohisa Sakamoto, Koji Koyamada

  Sep. 2019, The 15th Asia Symposium on Visualization (ASV15), English

  [Refereed]

  Symposium


• A Memory Efficient Image Composition-based Parallel Particle Based Volume Rendering

  Yoshiaki Yamaoka, Kengo Hayashi, Naohisa Sakamoto, Jorji Nonaka

  Mar. 2019, Journal of Advanced Simulation in Science and Engineering, 6(1) (1), 1 - 10, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• A Wireless Personal Safety Monitoring System for Firefighters

  Akihisa Yamada, Wataru Kayano, Ryosuke Kinoshita, Shoji Fujiyama, Yoichiro Tsutsui, Shuji Seki, Naohisa Sakamoto, Shinsuke Hara, Isao Shirakawa

  2019, 2019 34TH INTERNATIONAL TECHNICAL CONFERENCE ON CIRCUITS/SYSTEMS, COMPUTERS AND COMMUNICATIONS (ITC-CSCC 2019), 194 - 197, English

  International conference proceedings


• In situ adaptive timestep control and visualization based on the spatio-temporal variations of the simulation results.

  Yoshiaki Yamaoka, Kengo Hayashi, Naohisa Sakamoto, Jorji Nonaka

  2019, Proceedings of In Situ Infrastructures for Enabling Extreme-scale Analysis and Visualization (ISAV2019), 12 - 16, English

  [Refereed]

  International conference proceedings


• A Transfer Entropy based Visual Analytics System for Identifying Causality of Critical Hardware Failures - Case Study: CPU Failures in the K Computer

  Kazuki Koiso, Naohisa Sakamoto, Jorji Nonaka, Fumiyoshi Shoji

  Oct. 2018, In proc. of the 18th Asia Simulation Conference (AsiaSim2018), 946, 563 - 574, English

  [Refereed]

  International conference proceedings


• A Memory Efficient Parallel Particle-based Volume Rendering for Large-scale Distributed Unstructured Volume Datasets in HPC Environments

  Yoshiaki Yamaoka, Kengo Hayashi, Naohisa Sakamoto, Jorji Nonaka

  Oct. 2018, In proc. of the 18th Asia Simulation Conference (AsiaSim2018), 946, 552 - 562, English

  [Refereed]

  International conference proceedings

  Link to Kobe Univ. Repository (Kernel)


• Particle Based Volume Rendering using 234 Image Composition

  Yoshiaki Yamaoka, Kengo Hayashi, Naohisa Sakamoto, Jorji Nonaka

  Sep. 2018, In proc. of the 37th JSST Annual International Conference on Simulation Technology (JSST2018), 344 - 347, English

  [Refereed]

  International conference proceedings


• Development of a visual analytic system of exploring the failure causes using big log data on HPC systems

  Kazuki Koiso, Naohisa Sakamoto, Jorji Nonaka, Fumiyoshi Shoji

  Sep. 2018, In proc. of the 37th JSST Annual International Conference on Simulation Technology (JSST2018), 340 - 343, English

  [Refereed]

  International conference proceedings


• A Large Data Visualization Framework for SPARC64 fx HPC Systems - Case Study: K Computer Operational Environment -.

  Jorji Nonaka, Kenji Ono, Naohisa Sakamoto, Kengo Hayashi, Motohiko Matsuda, Fumiyoshi Shoji, Kentaro Oku, Masahiro Fujita, Kazuma Hatta

  2018, 2018 IEEE 8TH SYMPOSIUM ON LARGE DATA ANALYSIS AND VISUALIZATION (LDAV), 108 - 109, English

  [Refereed]

  International conference proceedings


• Flexible visualization framework for head-mounted display with gesture interaction interface.

  Pierre J. Jarsaillon, Naohisa Sakamoto, Akira Kageyama

  2018, Int. J. Model. Simul. Sci. Comput., 9(3) (3), 1840002 - 20, English

  [Refereed]

  Scientific journal


• Membrane Layer Method to Separate Simulation and Visualization for Large-scale In-situ Visualizations.

  Akira Kageyama, Naohisa Sakamoto, Kohei Yamamoto

  SciTePress, 2018, Proceedings of 8th International Conference on Simulation and Modeling Methodologies, Technologies and Applications (SIMULTECH 2018), 106 - 111, English

  [Refereed]

  International conference proceedings


• A Study on Open Source Software for Large-Scale Data Visualization on SPARC64fx based HPC Systems.

  Jorji Nonaka, Motohiko Matsuda, Takashi Shimizu, Naohisa Sakamoto, Masahiro Fujita, Keiji Onishi, Eduardo C. Inacio, Shun Ito, Fumiyoshi Shoji, Kenji Ono

  2018, PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING IN ASIA-PACIFIC REGION (HPC ASIA 2018), 278 - 288, English

  [Refereed]

  International conference proceedings


• An In-Situ Visualization Approach for the K Computer Using Mesa 3D and KVS

  Kengo Hayashi, Naohisa Sakamoto, Jorji Nonaka, Motohiko Matsuda, Fumiyoshi Shoji

  2018, In proc. of International Conference on High Performance Computing (ISC Workshop on In Situ Visualization 2018), 11203, 310 - 322, English

  [Refereed]

  International conference proceedings


• Layer Assignment Problem with Alignment Constraints of Source and Sink Vertices for Visualizing Evaluation Structures

  尾上 洋介, SAKAMOTO NAOHISA, 小山田 耕二

  An evaluation structure is a hierarchical structure of human cognition extracted from interviews based on the evaluation grid method. An evaluation structure can be defined as a directed acyclic graph (DAG) and be visualized by the Sugiyama framework that is a popular graph drawing method. In this paper, we discuss a layer assignment method that is a part of Sugiyama framework for interactive visualization of evaluation structures. We propose a novel heuristic method to approximately solve the layer assignment problem in polynomial time. We compare the performance of the proposed method with an exact method and an existing approximate solution method. It is demonstrated that the proposed method produces readable layout in a short time.

  応用数理学会, Dec. 2017, 応用数理, 27(4) (4), 160 - 167, Japanese


• Message from the chairs: NICOInt 2017

  Kiyoshi Kiyokawa, Yasuo Ebara, Naohisa Sakamoto, Koji Koyamada

  Institute of Electrical and Electronics Engineers Inc., Sep. 2017, Proceedings - 2017 NICOGRAPH International, NICOInt 2017, ix, English

  [Refereed]

  International conference proceedings


• Interactive Visualization of Large-Scale 3D Scattered Data from a Tsunami Simulation

  Kun Zhao, SAKAMOTO NAOHISA, Koji Koyamada, Satoshi Tanaka, Kohei Murotani, Seiichi Koshizuka

  Jun. 2017, International Journal of Industrial Engineering: Theory, Applications and Practice (IJIETAP), 24(2) (2), 207 - 219, English

  [Refereed]

  Scientific journal


• Chair message.

  Daniel Weiskopf, Yingcai Wu, Tim Dwyer, Yun Jang, Naohisa Sakamoto

  IEEE Computer Society, 2017, 2017 IEEE Pacific Visualization Symposium(PacificVis)

  International conference proceedings


• Development of interactive visualization system for volume data using Head-Mounted Display

  Pierre Jarsaillon, Yu Han, Naohisa Sakamoto

  2017, 2017 NICOGRAPH INTERNATIONAL (NICOINT), 98 - 98, English

  [Refereed]

  International conference proceedings


• Stylized Semi-transparent Streamlines by Stochastic Rendering Approach

  Tomohisa Tanaka, Naohisa Sakamoto

  2017, 2017 NICOGRAPH INTERNATIONAL (NICOINT), 96 - 96, English

  [Refereed]

  International conference proceedings


• Layered Graph Drawing for Visualizing Evaluation Structures.

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Kazuo Misue, Koji Koyamada

  An evaluation structure is a hierarchical structure of human cognition extracted from interviews based on the evaluation grid method. An evaluation structure can be defined as a directed acyclic graph (DAG). The authors propose a layer-assignment method that is part of the Sugiyama framework, a popular method for drawing DAGs, to satisfy the requirements for drawing evaluation structures. Their evaluations demonstrate that the layered graph drawing produced by the proposed layer-assignment method is preferred by users and aids in the understanding of evaluation structures.

  IEEE, 2017, IEEE Computer Graphics and Applications, 37(2) (2), 20 - 30, English, International magazine

  [Refereed]

  Scientific journal


• INTERACTIVE VISUALIZATION OF LARGE-SCALE 3D SCATTERED DATA FROM A TSUNAMI SIMULATION

  Kun Zhao, Sakamoto Naohisa, Koji Koyamada, Satoshi Tanaka, Kohei Murotani, Seiichi Koshizuka

  2017, INTERNATIONAL JOURNAL OF INDUSTRIAL ENGINEERING-THEORY APPLICATIONS AND PRACTICE, 24(2) (2), 207 - 219, English

  [Refereed]

  Scientific journal


• Layered Graph Drawing for Visualizing Evaluation Structures.

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Kazuo Misue, Koji Koyamada

  2017, IEEE Computer Graphics and Applications, 37(2) (2), 20 - 30, English, International magazine

  [Refereed]

  Scientific journal


• Using interactive particle-based rendering to visualize a large-scale time-varying unstructured volume with mixed cell types.

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  2017, 2017 IEEE PACIFIC VISUALIZATION SYMPOSIUM (PACIFICVIS), 185 - 189, English

  [Refereed]

  International conference proceedings


• Distributed Particle-Based Rendering Framework for Large Data Visualization on HPC Environments.

  Jorji Nonaka, Naohisa Sakamoto, Takashi Shimizu, Masahiro Fujita, Kenji Ono, Koji Koyamada

  2017, 2017 INTERNATIONAL CONFERENCE ON HIGH PERFORMANCE COMPUTING & SIMULATION (HPCS), 300 - 307, English

  [Refereed]

  International conference proceedings


• Parallel particle-based volume rendering using adaptive particle size adjustment technique.

  Kengo Hayshi, Takashi Shimizu, Naohisa Sakamoto, Jorji Nonaka

  2017, SA'17: SIGGRAPH ASIA 2017 SYMPOSIUM ON VISUALIZATION, 11 - 8, English

  [Refereed]

  International conference proceedings


• Development of a visual analytics system for cell division dynamics in early C.elegans embryos.

  Sayaka Nagai, Naohisa Sakamoto

  2017, SA'17: SIGGRAPH ASIA 2017 SYMPOSIUM ON VISUALIZATION, 19 - 8, English

  [Refereed]

  International conference proceedings


• A visual causal exploration framework case study: a torrential rain and a flash flood in Kobe city.

  Jorji Nonaka, Naohisa Sakamoto, Yasumitsu Maejima, Kenji Ono, Koji Koyamada

  2017, SA'17: SIGGRAPH ASIA 2017 SYMPOSIUM ON VISUALIZATION, 8 - 8, English

  [Refereed]

  International conference proceedings


• Development of support system for estimation of earthquake fault plane with hypocenter data

  Yukio Yasuhara, Naohisa Sakamoto, Yasuo Ebara, Hiroshi Katao, Koji Koyamada

  2017, JOURNAL OF ADVANCED SIMULATION IN SCIENCE AND ENGINEERING, 4(1) (1), 132 - 142, English

  [Refereed]

  Scientific journal

  Link to Kobe Univ. Repository (Kernel)


• Web-based Visualization System for Large-Scale Volume Datasets

  Takashi Shimizu, Naohisa Sakamoto, Jorji Nonaka, Kenji Ono, Koji Koyamada

  Oct. 2016, Proc. of International Conference on Simulation Technology (JSST2016), 253 - 260, English

  [Refereed]

  International conference proceedings


• Minimizing the Number of Edges via Edge Concentration in Dense Layered Graphs.

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  Edge concentration in dense bipartite graphs is a technique for reducing the numbers of edges and edge crossings in graph drawings. The conventional method proposed by Newbery is designed to reduce the number of edge crossings; however, it does not always reduce the number of edges. Reducing the number of edges is also an important factor for improving the readability of graphs. However, no edge concentration method with the explicit purpose of minimizing the number of edges has previously been studied. In this study, we propose a novel, efficient heuristic method for minimizing the number of edges during edge concentration. We demonstrate the efficiency of the proposed method via a comparison using randomly generated graphs. We find that Newbery's method fails to reduce the number of edges when the number of vertices is large. By contrast, the proposed method achieves an average compression ratio of 47 to 82 percent for all generated graph groups. We also present a real-world application of the proposed method using a causality network of biological data.

  IEEE, Jun. 2016, IEEE transactions on visualization and computer graphics, 22(6) (6), 1652 - 1661, English, International magazine

  [Refereed]

  Scientific journal


• E-Grid: a visual analytics system for evaluation structures

  Onoue, Yosuke, Kukimoto, Nobuyuki, Sakamoto, Naohisa, Koyamada, Koji

  Springer Berlin Heidelberg, 2016, Journal of Visualization, 1 - 16

  [Refereed]

  Scientific journal


• Visualizing Evaluation Structures using Layered Graph Drawings

  Onoue, Yosuke, Kukimoto, Nobuyuki, Sakamoto, Naohisa, Misue, Kazuo, Koyamada, Koji

  IEEE, 2016

  [Refereed]

  Scientific journal


• A Path-Line-Based Modeling for Fishing Prediction

  Koji Koyamada, Katsumi Konishi, Naohisa Sakamoto, Marohito Takami

  2016, MODEL DESIGN AND SIMULATION ANALYSIS, 603, 79 - 88, English

  [Refereed]

  International conference proceedings


• Minimizing the Number of Edges via Edge Concentration in Dense Layered Graphs

  Onoue, Yosuke, Kukimoto, Nobuyuki, Sakamoto, Naohisa, Koyamada, Koji

  2016, IEEE transactions on visualization and computer graphics, 22(6) (6), 1652 - 1661, English, International magazine

  [Refereed]

  Scientific journal


• Parallelized fusion visualization system

  Miyachi, Hideo, Sakamoto, Naohisa, Koyamada, Koji

  2016, Artificial Life and Robotics, 21(1) (1), 120 - 124, English

  [Refereed]

  Scientific journal


• E-Grid: a visual analytics system for evaluation structures.

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  2016, J. Vis., 19(4) (4), 753 - 768, English

  [Refereed]

  Scientific journal


• Volume Rendering for 3D Scattered data with Interactive Particle-based Rendering

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada, Satoshi Tanaka, Kohei Murotani, Seiichi Koshizuka

  Nov. 2015, Proc. of International Conference on Systems Simulation (AsiaSim2015), English

  [Refereed]

  International conference proceedings


• A path-line-based approach for developing a fishing ground model

  Koji Koyamada, Katsumi Konishi, Naohisa Sakamoto, Marohito Takami

  Nov. 2015, Proc. of International Conference on Systems Simulation (AsiaSim2015), English

  [Refereed]

  International conference proceedings


• Word cloud visualization of Evaluation Structures focusd on Location

  Keita Ozawa, Naohisa Sakamoto, Koji Koyamada

  Oct. 2015, Proc. of International Conference on Simulation Technology (JSST2015), 451 - 454, English

  [Refereed]

  International conference proceedings


• Visualization of Large-scale Time-varying Unstruc- tured Volume Data with Interactive Particle-based Rendering

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  Oct. 2015, Proc. of International Conference on Simulation Technology (JSST2015), 12 - 15, English

  [Refereed]

  International conference proceedings


• Network Coarse-Graining for Evaluation Structures

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  Oct. 2015, Proc. of International Conference on Simulation Technology (JSST2015), 447 - 450, English

  [Refereed]

  International conference proceedings


• A visualization for the dynamic behaviors of the mixture of water mass for northwestern pacific near Japan (vol 4, 1341002, 2013)

  Kun Zhao, Satoshi Nakada, Naohisa Sakamoto, Koji Koyamada, Chandrajit Bajaj, Yoichi Ishikawa, Toshiyuki Awaji, Teiji In, Sei-Ichi Saitoh

  Jun. 2015, INTERNATIONAL JOURNAL OF MODELING SIMULATION AND SCIENTIFIC COMPUTING, 6(2) (2), English

  [Refereed]


• Visualization of Tsunami Simulation Data with Particle-based Rendering (第 43 回可視化情報シンポジウム 講演論文集)--(オーガナイズドセッション ビジュアルデータマイニング Ⅱ (シミュレーション学会との共同開催))

  Zhao, Kun, Sakamoto, Naohisa, Koyamada, Koji

  可視化情報学会, 2015, 可視化情報学会誌= ournal of the Visualization Society of Japan, 35(1) (1), 227 - 232, English

  [Refereed]

  Scientific journal


• Time-Varying Volume Compression in Spatio-Temporal Domain

  Zhao, Kun, Sakamoto, Naohisa, Koyamada, Koji

  2015, 日本シミュレーション学会英文誌, 1(1) (1), 171 - 187, Japanese

  [Refereed]

  Scientific journal


• Remote visualization system based on particle based volume rendering.

  Takuma Kawamura, Yasuhiro Idomura, Hiroko Miyamura, Hiroshi Takemiya, Naohisa Sakamoto, Koji Koyamada

  2015, VISUALIZATION AND DATA ANALYSIS 2015, 9397, 93970, English

  [Refereed]

  International conference proceedings


• PetaFlow: a global computing-networking-visualisation unit with social impact

  Ancel, Alexandre, Assenmacher, Ingo, Baba, Ken Ichi, Cisonni, Julien, Fujiso, Yo, Gon{\c{c } }alves, Paulo, Imbert, Matthieu, Koyamada, Koji, Neyron, Pierre, Kazunori, Nozaki and

  2015, International Research Journal of Computer Science, 2(4) (4)

  [Refereed]

  Scientific journal


• Kvs: A simple and effective framework for scientific visualization

  Sakamoto, Naohisa, Koyamada, Koji

  Japan Society for Simulation Technology, 2015, 日本シミュレーション学会英文誌, 2(1) (1), 76 - 95

  [Refereed]

  Scientific journal


• CORRIGENDUM:" A visualization for the dynamic behaviors of the mixture of water mass for northwestern pacific near Japan"

  Zhao, Kun, Nakada, Satoshi, Sakamoto, Naohisa, Koyamada, Koji, Bajaj, Ch, rajit, Ishikawa, Yoichi, Awaji, Toshiyuki, In, Teiji, Saitoh, Sei-Ichi

  2015, International Journal of Modeling, Simulation, and Scientific Computing, 6(02) (02), 1592002 - 1592002, English

  [Refereed]

  Scientific journal


• A Path-Line-Based Modeling for Fishing Prediction

  Koyamada Koji, Konishi Katsumi, Sakamoto Naohisa, Takami Marohito

  2015, Communications in Computer and Information Science, 603, 79 - 88

  [Refereed]


• KVS: A simple and effective framework for scientific visualization

  Naohisa Sakamoto, Koji Koyamada

  2015, JOURNAL OF ADVANCED SIMULATION IN SCIENCE AND ENGINEERING, 2(1) (1), 76 - 95, English

  [Refereed]

  Scientific journal


• Adaptive fused visualization for large-scale blood flow dataset with particle-based rendering.

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  Springer Berlin Heidelberg, 2015, J. Vis., 18(2) (2), 133 - 145

  [Refereed]

  Scientific journal


• Adaptive fused visualization for large-scale blood flow dataset with particle-based rendering

  Zhao, Kun, Sakamoto, Naohisa, Koyamada, Koji

  2015, Journal of Visualization, 18(2) (2), 133 - 145, English

  [Refereed]

  Scientific journal


• Voting-based ensemble-averaging visualization for water mass distribution

  Zhao, Kun, Nakada, Satoshi, Sakamoto, Naohisa, Koyamada, Koji

  2015, Journal of Visualization, 18(4) (4), 719 - 731, English

  [Refereed]

  Scientific journal


• 噴火湾においてホタテガイ幼生の分布可視化

  Naohisa Sakamoto

  可視化情報学会, 2014, 可視化情報学会誌= ournal of the Visualization Society of Japan, 34(1) (1), 357 - 362, English

  [Refereed]

  Scientific journal


• Visual Analysis of Habitat Suitability Index Model For Predicting the Locations of Fishing Grounds

  Takashi Uenaka, Naohisa Sakamoto, Koji Koyamada

  2014, 2014 IEEE Pacific Visualization Symposium (PacificVis), 306 - 310, English

  [Refereed]

  International conference proceedings


• Fusion visualization for fluid dynamics in blood vessel

  Miyachi, Hideo, Ishida, Tomoyuki, Sakamoto, Naohisa, Koyamada, Koji

  2014, Artificial Life and Robotics, 19(3) (3), 286 - 290, English

  [Refereed]

  Scientific journal


• Fused Visualization for Large-Scale Time-Varying Volume Data with Adaptive Particle-Based Rendering

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  2014, ASIASIM 2014, 474, 228 - +, English

  [Refereed]

  Scientific journal


• Fused Visualization for Large-Scale Blood Flow Dataset

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  2014, LIFE SYSTEM MODELING AND SIMULATION, 461, 246 - 255, English

  [Refereed]

  International conference proceedings


• A Stochastic Approach for Rendering Multiple Irregular Volumes

  Naohisa Sakamoto, Koji Koyamada

  2014, 2014 IEEE PACIFIC VISUALIZATION SYMPOSIUM (PACIFICVIS), 272 - 276, English

  [Refereed]

  International conference proceedings


• AsiaSim 2014: 14th International Conference on Systems Simulation Kitakyushu, Japan, October 26-30, 2014 Proceedings

  Satoshi Tanaka, Kyoko Hasegawa, Rui Xu, Naohisa Sakamoto, Stephen John Turner

  Springer Verlag, 2014, Communications in Computer and Information Science, 474, English

  [Refereed]

  Scientific journal


• Applying Fusion Visualization to Unstructured Data

  Hideo Miyachi, Naohisa Sakamoto, Koji Koyamada

  2014, 2014 17TH INTERNATIONAL CONFERENCE ON NETWORK-BASED INFORMATION SYSTEMS (NBIS 2014), 414 - 417, English

  [Refereed]

  International conference proceedings


• Application of Stochastic Point-based Rendering to Transparent Visualization of Large-scale Laser-scanned Data of 3D Cultural Assets

  Satoshi Tanaka, Makoto Uemura, Kyoko Hasegawa, Takehiko Kitagawa, Takahiro Yoshida, Asuka Sugiyama, Hiromi T. Tanaka, Atsushi Okamoto, Naohisa Sakamoto, Koji Koyamada

  2014, 2014 IEEE PACIFIC VISUALIZATION SYMPOSIUM (PACIFICVIS), 267 - 271, English

  [Refereed]

  International conference proceedings


• Fusion visualization of surface and volume on AVS/Express

  Hideo Miyaehil, Koji Koyamada, Naohisa Sakamoto

  2013, PROCEEDINGS OF THE EIGHTEENTH INTERNATIONAL SYMPOSIUM ON ARTIFICIAL LIFE AND ROBOTICS (AROB 18TH '13), 89 - 92, English

  [Refereed]

  International conference proceedings


• PetaFlow - an example of communication and computational technologies with social impact

  A. Ancel, I. Assenmacher, K. Baba, J. Cisonni, Y. Fujiso, P. Gonalves, M. Imbert, K. Koyamada, P. Neyron, K. Nozaki, H. Ohsaki, A. C. Orgerie, X. Pelorson, B. Raffin, N. Sakamoto, E. Sakane, S. Shimojo, A. Van Hirtum, S. Wada

  2013, 2013 IEEE 37TH ANNUAL COMPUTER SOFTWARE AND APPLICATIONS CONFERENCE WORKSHOPS (COMPSACW), 703 - 708, English

  [Refereed]

  International conference proceedings


• Compression for large-scale time-varying volume data using spatio-temporal features

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  Springer Verlag, 2013, Communications in Computer and Information Science, 402, 136 - 148, English

  [Refereed]

  International conference proceedings


• A Visualization Study for the Dynamic Behaviors of Water Masses for Northwestern Pacific near Japan (第 41 回可視化情報シンポジウム講演論文集)--(オーガナイズドセッション ビジュアルデータマイニング Ⅱ 日本シミュレーション学会との共同企画)

  Zhao, Kun, Nakada, Satoshi, Sakamoto, Naohisa

  可視化情報学会, 2013, 可視化情報学会誌= ournal of the Visualization Society of Japan, 33(1) (1), 277 - 284, English

  [Refereed]

  Scientific journal


• A VASUALIZATION FOR THE DYNAMIC BEHAVIORS OF THE MIXTURE OF WATER MASS FOR NORTHWESTERN PACIFIC NEAR JAPAN

  ZHAO, KUN, NAKADA, SATOSHI, SAKAMOTO, NAOHISA, KOYAMADA, KOJI, BAJAJ, CHANDRAJIT, ISHIKAWA, YOICHI, AWAJI, TOSHIYUKI, IN, TEIJI, SAITOH, SEI-ICHI

  2013, International Journal of Modeling, Simulation, and Scientific Computing, 4(supp01) (supp01), 1341002 - 1341002, English

  [Refereed]

  Scientific journal


• High-quality particle-based volume rendering for large-scale unstructured volume datasets

  Sakamoto, Naohisa, Maeda, Naoya, Kawamura, Takuma, Koyamada, Koji

  2013, Journal of visualization, 16(2) (2), 153 - 162, English

  [Refereed]

  Scientific journal


• Visualization of Plasma Plume Collisions Using Fused Volume Data

  Naoya Kawamoto, Yuiti Hatanaka, Takashi Yamamoto, Kyoko Hasegawa, Susumu Nakata, Satoshi Tanaka, Naohisa Sakamoto, Koji Koyamada, Seigo Misaki, Kazuo Tanaka

  2012, ADVANCED METHODS, TECHNIQUES, AND APPLICATIONS IN MODELING AND SIMULATION, 4, 484 - 491, English

  [Refereed]

  International conference proceedings


• Tiled Display Visualization System with Multi-touch Control

  Jun Nishimura, Naohisa Sakamoto, Koji Koyamada

  2012, ADVANCED METHODS, TECHNIQUES, AND APPLICATIONS IN MODELING AND SIMULATION, 4, 492 - 497, English

  [Refereed]

  International conference proceedings


• The Visualization of Degenerate Surface in 3D Diffusion Tensor Field

  Zhao, Kun, Sakamoto, Naohisa, Koyamada, Koji

  Japan Society for Simulation Technology, 2012, 日本シミュレーション学会論文誌, 4(3) (3), 62 - 70, English

  [Refereed]

  Scientific journal


• Particle-Based Volume Rendering of Remote Volume Datasets Using FlowVR

  Allan Lorant, Alexandre Ancel, Kun Zhao, Naohisa Sakamoto, Koji Koyamada, Bruno Raffin

  2012, ASIASIM 2012, PT I, 323(PART 1) (PART 1), 285 - +, English

  [Refereed]

  International conference proceedings


• Particle-based transparent rendering of implicit surfaces and its application to fused visualization

  Tanaka, Satoshi, Hasegawa, Kyoto, Shimokubo, Yoshiyuki, Kaneko, Tomonori, Kawamura, Takuma, Nakata, Susumu, Ojima, Saori, Sakamoto, Naohisa, Tanaka, Hiromi, Koyamada, Koji

  The Eurographics Association, 2012, 14th Eurographics Conference on Visualization

  [Refereed]

  Scientific journal


• Extraction of Vortices and Exploration of the Ocean Data by Visualization System

  Chi Zhang, Takashi Uenaka, Naohisa Sakamoto, Koji Koyamada

  2012, SYSTEM SIMULATION AND SCIENTIFIC COMPUTING, PT II, 327(PART 2) (PART 2), 114 - 123, English

  [Refereed]

  International conference proceedings


• Detection of Linear Relationship among Dimensions in Multivariate Data by Parallel Coordinates

  Chi Zhang, Naohisa Sakamoto, Koji Koyamada

  2012, ASIASIM 2012, PT I, 323(PART 1) (PART 1), 175 - 181, English

  [Refereed]

  International conference proceedings


• Clustered Parallel Coordinates with High-Speed k-Means Algorithm and Out-of-Core Feature

  Chi Zhang, Naohisa Sakamoto, Koji Koyamada

  2012, ADVANCED METHODS, TECHNIQUES, AND APPLICATIONS IN MODELING AND SIMULATION, 4, 441 - 455, English

  [Refereed]

  International conference proceedings


• A Volume Compression Scheme Based on Block Division with Fast Cubic B-spline Evaluation

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  2012, ASIASIM 2012, PT III, 325(PART 3) (PART 3), 373 - +, English

  [Refereed]

  International conference proceedings


• A Visualization Study of Vortices Extracted from the Tremendous Ocean Simulation Data: An Application in Funka Bay

  Nakada, Satoshi, Uenaka, Takashi, Ishikawa, Yoichi, Matsui, Kenta, Sakamoto, Naohisa, Koyamada, Koji, Awaji, Toshiyuki, Saitoh, Sei-Ichi

  日本シミュレーション学会, 2012, 日本シミュレーション学会論文誌, 4(4) (4), 145 - 152

  [Refereed]

  Scientific journal


• A Temporal Coherence Based Framework for Visualizing Time-Varying Unstructured Volume with PBVR

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  2012, ASIASIM 2012, PT I, 323(PART 1) (PART 1), 163 - +, English

  [Refereed]

  International conference proceedings


• A new framework for visualizing a time-varying unstructured grid dataset with pbvr

  Zhao, Kun, Nishimura, Jun, Sakamoto, Naohisa, Koyamada, Koji

  2012, Advanced Methods, Techniques, and Applications in Modeling and Simulation, 4, 506 - 516, English

  [Refereed]

  International conference proceedings


• An Efficient Hyperstreamline Visualization Method on Large-Scale Unstructured Datasets

  Jiazhen Guo, Sakamoto Naohisa, other

  日本計算工学会, 2012, 計算工学講演会論文集 Proceedings of the Conference on Computational Engineering and Science, 17, 4p, English

  [Refereed]


• Peta-flow computing: Vision and challenges

  Hiroyuki Ohsaki, Kazunori Nozaki, Ken'ichi Baba, Eisaku Sakane, Naohisa Sakamoto, Kohji Koyamada, Shinji Shimojo

  IEEE Computer Society, 2011, Proceedings - 11th IEEE/IPSJ International Symposium on Applications and the Internet, SAINT 2011, 256 - 259, English

  [Refereed]

  International conference proceedings


• Level-of-Detail Rendering of Large-Scale Irregular Volume Datasets Using Particles

  Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  Sep. 2010, JOURNAL OF COMPUTER SCIENCE AND TECHNOLOGY, 25(5) (5), 905 - 915, English

  [Refereed]

  Scientific journal


• Particle-based multiple irregular volume rendering on CUDA

  Ding Zhongming, Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  Sep. 2010, SIMULATION MODELLING PRACTICE AND THEORY, 18(8) (8), 1172 - 1183, English

  [Refereed]

  Scientific journal


• Visualization of large-scale CFD simulation results using distributed particle-based volume rendering

  Naohisa Sakamoto, Hiroshi Kuwano, Takuma Kawamura, Koji Koyamada, Kazunori Nozaki

  Multi Science Publishing, Jun. 2010, International Journal of Emerging Multidisciplinary Fluid Sciences, 2(2-3) (2-3), 73 - 86, English

  [Refereed]

  Scientific journal


• Computer Graphics and Visualization Current Issue| Archive| Adv Search<< Previous Articles| Next Articles

  Kawamura, Takuma, Sakamoto, Naohisa, Koyamada, Koji

  2010, Journal of Computer Science and Technology, 25(5) (5), 905 - 915

  [Refereed]

  Scientific journal


• Petaflow - A project towards information and communication technologies in society

  Paulo Gonçalves, Xavier Grandchampy, Xavier Pelorsony, Bruno Raffinz, Annemie Van Hirtumy, Pascale Vicat-Blanc, Ken-Ichi Baba, Julien Cisonni, Yasuo Ebara, Kazunori Nozaki, Hiroyuki Ohsaki, Shigeo Wada, Takuma Kawamura, Kohji Koyamada, Eisaku Sakanez, Naohisa Sakamoto, Shinji Shimojoy

  IEEE Computer Society, 2010, Proceedings - 2010 10th Annual International Symposium on Applications and the Internet, SAINT 2010, 347 - 350, English

  [Refereed]

  International conference proceedings


• Improvement of particle-based volume rendering for visualizing irregular volume data sets

  Noahisa Sakamoto, Takuma Kawamura, Koji Koyamada, Kazunori Nozaki

  2010, Computers & Graphics, 34(1) (1), 34 - 42, English

  [Refereed]

  Scientific journal


• Grid-independent metropolis sampling for volume visualization

  Satoshi Tanaka, Kyoko Hasegawa, Susumu Nakata, Hideo Nakajima, Takuya Hatta, Frederika Rambu Ngana, Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  2010, International Journal of Modeling, Simulation, and Scientific Computing, 1(2) (2), 199 - 218, English

  [Refereed]

  Scientific journal


• A High-Quality Sampling Technique of PBVR for Unstructured Hexahedral Mesh Data

  Kawamura Takuma, Koyamada Koji, Sakamoto Naohisa, Tanaka Satoshi

  2010, 10

  [Refereed]


• Level-of-detail rendering of large-scale irregular volume datasets using particles

  Kawamura, Takuma, Sakamoto, Naohisa, Koyamada, Koji

  Springer US, 2010, Journal of Computer Science and Technology, 25(5) (5), 905 - 915

  [Refereed]

  Scientific journal


• Interactive Hierarchical RSM Applied to Parameter Optimization of Photonic Crystal Nanocavities

  Teppei Tanaka, Akira Yamasaki, Koji Koyamada, Naohisa Sakamoto

  2009, ISCE: 2009 IEEE 13TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2, 711 - 715, English

  [Refereed]

  International conference proceedings


• 可視化プログラミングの基礎（１）有限要素法とボリュームレンダリング

  坂本尚久, 小山田耕二

  Oct. 2008, 計算工学, 13(4) (4), 1934 - 1940, Japanese

  [Refereed]


• Covering dairy slurry stores with hydrophobic fertilisers reduces greenhouse gases and other polluting gas emissions

  Sakamoto, Naohisa, Tani, Masayuki, Navarrete, Ian A, Koike, Masanori, Umetsu, Kazutaka

  CSIRO PUBLISHING, 2008, Animal Production Science, 48(2) (2), 202 - 207

  Scientific journal


• Spatiotemporal Analysis of Morphological Cahnges in Cell Death Using Multiple Volume Visualization

  Sakamoto, Naohisa, Kawamura, Takuma, Kioka, Miki, Koyamada, Koji, Sakamaki, Kazuhiro

  2008, IEEE Visualization Proceedings Compendium, 52 - 53

  [Refereed]

  Scientific journal


• Simulation and Volume Visualization

  Sakamoto, N., Koyamada, K.

  JAPAN TECHNICAL INFORMATION SERVICE, 2008, JOURNAL-JAPAN SOCIETY FOR SIMULATION TECHNOLOGY, 27(1) (1), 8 - 8

  [Refereed]

  Scientific journal


• Multi-volume rendering using particle fusion

  Sakamoto Naohisa, Koyamada Koji, Saito Ayumu, Kimura A, Tanaka S

  2008

  [Refereed]


• Hardware-Accelerated Particle-Based Volume Rendering for Multiple Irregular Volumes

  Naohisa Sakamoto, Ding Zhongming, Takuma Kawamura, Koji Koyamada

  2008, ADVANCES IN VISUAL COMPUTING, PT II, PROCEEDINGS, 5359, 970 - +, English

  [Refereed]

  International conference proceedings


• GPU Acceleration of Improved Particle-based Volume Rendering for Irregular-Grid Volume Data

  Zhongming, Ding, Kawamura, Takuma, Sakamoto, Naohisa, Koyamada, Koji

  2008, Asia-Pacific Symposium on Visualisation 2007, APVIS 2007, Proceedings, 129 - 132

  [Refereed]

  Scientific journal


• An Interactive Approach for Hierarchical Parameter Optimization

  Tanaka, Teppei, Itoh, Takayuki, Sakamoto, Naohisa, Koyamada, Koji

  We propose a novel interactive parameter optimization technique which asks users to determine whether further exploration is required by using a hierarchical visualization technique. Our technique generates a k-d tree and uses the coefficient of multiple determinations (R²) for tree-branching; however, this requires a huge amount of computation since it processes the response surface at every leaf node of the k-d tree, including those that may not have minimum parameters. To solve the problem, we introduce human evaluation of the display on the computer screen, in which every tree-node is evenly displayed regardless of its hierarchical level. We confirmed the effectiveness of the proposed technique by searching for pre-determined parameters in some test functions and biological cell simulation results.

  The Japan Society of Mechanical Engineers, 2008, Journal of Fluid Science and Technology, 3(4) (4), 586 - 597, English

  [Refereed]

  Scientific journal


• Enzyme electrode formed by evaporative concentration and its performance characterization.

  Masatoshi Hashimoto, Naohisa Sakamoto, Sanjay Upadhyay, Junji Fukuda, Hiroaki Suzuki

  A highly concentrated immobilized enzyme layer was formed on a small working electrode, and the behavior of the electrode as an amperometric sensor was examined. To this end, a super-hydrophobic layer was formed in an area other than the sensitive area by using polytetrafluoroethylene (PTFE) beads. A small droplet of an enzyme solution containing glucose oxidase (GOD) and bovine serum albumin (BSA) was placed on the sensitive area, concentrated by evaporation, and crosslinked with glutaraldehyde. With the same enzyme activity per unit area, the current density increased with smaller working electrodes. Also, the current density increased with higher enzyme loadings up to a limiting value. In addition, the linear range of the calibration plot was expanded to higher glucose concentrations. The enzyme electrode fabricated by the novel method was incorporated in a micro-flow channel. Compared with large enzyme electrodes with the same enzyme activity per unit area, smaller electrodes showed a significant increase in the current density and a decrease in the flow dependence. The conversion efficiency could be improved by narrowing the flow channel and increasing the number of electrodes, which was comparable with a large electrode placed in a shallow flow channel.

  Jun. 2007, Biosensors & bioelectronics, 22(12) (12), 3154 - 60, English, International magazine

  Scientific journal


• タイルドディスプレイを用いた多地点遠隔コミュニケーションシステムに関する研究 (一般セッション 1, 顔・ジェスチャの認識・理解)

  Naohisa Sakamoto

  一般社団法人電子情報通信学会, 2007, 電子情報通信学会技術研究報告. PRMU, パターン認識・メディア理解, 107(206) (206), 1

  [Refereed]

  Scientific journal


• Visualization of Medical Volumetric Data based on Grid-Independent Monte Carlo Sampling

  Ngana, Frederika Rambu, Hatta, Takuya, Sakamoto, Naohisa, Nonaka, Jorji, Tanaka, Koji Koyamada, Satoshi

  2007, ICSIIT 2007, 232 - 232

  [Refereed]

  Scientific journal


• Particle-based volume rendering

  Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada, Satoshi Tanaka

  IEEE, 2007, Asia-Pacific Symposium on Visualisation 2007, APVIS 2007, Proceedings, 129 - 132, English

  [Refereed]

  International conference proceedings


• Hierarchical response surface methodology for parameter optimization: Efficiency of a hierarchical RSM with a hessian matrix

  Teppei Tanaka, Koji Sakai, Yukiko Yamashita, Naohisa Sakamoto, Koji Koyamada

  2007, SYSTEMS MODELING AND SIMULATION: THEORY AND APPLICATIONS, ASIA SIMULATION CONFERENCE 2006, 213 - +, English

  [Refereed]

  International conference proceedings


• Particle-based volume rendering

  Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada, Satoshi Tanaka

  2007, Asia-Pacific Symposium on Visualisation 2007, APVIS 2007, Proceedings, 27(2) (2), 129 - 132, English

  [Refereed]


• GPU Acceleration of Improved Particle-based Volume Rendering for Irregular-Grid Volume Data

  Zhongming Ding, Kawamura Takuma, Sakamoto Naohisa, Koyamada Koji

  2007, Asia-Pacific Symposium on Visualisation 2007, APVIS 2007, Proceedings, 129 - 132

  [Refereed]


• Framework for creating new discriminants: Combined diffusion and perfusion studies in stroke patients

  Shiho Takagi, Koji Sakai, Kei Yamada, Kousuke Kudo, Yukio Yasuhara, Koji Koyamada, Tsunehiko Nishimura

  2007, PROCEEDINGS OF THE FIFTH IASTED INTERNATIONAL CONFERENCE ON BIOMEDICAL ENGINEERING, 166 - 170, English

  [Refereed]

  International conference proceedings


• Development of the Support System for Estimation of Fault Plane with Hypocenter Data

  Yasuhara, Y., Sakamoto, N., Ebara, Y., Katao, H., Koyamada, K.

  JAPAN TECHNICAL INFORMATION SERVICE, 2007, JOURNAL-JAPAN SOCIETY FOR SIMULATION TECHNOLOGY, 26(4) (4), 24 - 24

  [Refereed]

  Scientific journal


• A real-time sensor network visualization system using KVS: Kyoto visualization system.

  Norihisa Segawa, Yukio Yasuhara, Naohisa Sakamoto, Tomoki Yoshihisa, Yasuo Ebara, Koji Koyamada

  ACM, 2007, Proceedings of the 5th International Conference on Embedded Networked Sensor Systems, SenSys 2007, Sydney, NSW, Australia, November 6-9, 2007, 367 - 368

  [Refereed]

  International conference proceedings


• A real-time human movement transfer system for an omnidirectional display

  Naohisa Sakamoto, Yukio Yasuhara, Nobuyuki Kukimoto, Yasuo Ebara, Koji Koyamada

  2007, ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS, 90(12) (12), 77 - 86, English

  [Refereed]

  Scientific journal


• “Speed-Up of Marching Diamonds and Evaluation oh Methods for Isosurface Extraction from Tetrahedral Mesches”

  Akira Yamasaki, Yukio Yasuhara, Naohisa Sakamoto, Koji Koyamada

  2007, 小山田耕二（教授） 【学会発表】 （査読付国際会議） NICOGRAPH International 2007, CD-ROM, 2007, English

  [Refereed]


• Framework for creating new discriminats for detecting DTI properties: DTI mapper

  Koji Sakai, Naohisa Sakamoto, Jorji Nonaka, Yukio Yasuhara, Koji Koyamada

  2006, 2006 28TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-15, 1, 1148 - +, English, International magazine

  [Refereed]

  International conference proceedings


• Volume Rendering Using Tiny Particles.

  Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada, Satoshi Tanaka

  IEEE Computer Society, 2006, Eigth IEEE International Symposium on Multimedia (ISM 2006), 11-13 December 2006, San Diego, CA, USA, 734 - 737

  [Refereed]

  International conference proceedings


• 3D modeling and displaying system for volume communication

  N Sakamoto, N Kukimoto, Y Yasuhara, Y Ebara, K Koyamada

  May 2005, JSME INTERNATIONAL JOURNAL SERIES B-FLUIDS AND THERMAL ENGINEERING, 48(2) (2), 247 - 251, English

  [Refereed]

  Scientific journal


• Virtual object reconstruction in real world

  K Sakai, N Sakamoto, K Koyamada, T Hasegawa

  2005, 11TH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS WORKSHOPS, VOL II, PROCEEDINGS,, 214 - 218, English

  [Refereed]

  International conference proceedings


• Data reduction by applying an image-based modeling and rendering technique to CG models

  Miyachi, Hideo, Sakamoto, Naohisa

  2005, Journal of visualization, 8(4) (4), 331 - 338, English

  [Refereed]

  Scientific journal


• A203 IPT を用いた地震における岩盤破断現象の三次元可視化

  久木元伸如, 安原幸生, 坂本尚久, ノナカジョルジ, 江原康生, 小山田耕二

  It is highly important to comprehend the destruction phenomenon of bedrock structures because earthquakes usually occur by destroying the rocks inside the earth. This destruction sometimes oc-curs concurrently at different places because of aftershocks. For instance, the Mid-Niigata Prefecture Earthquake occurred in 2004 has generated several aftershocks, as a result it was considered an uncommon and complex earthquake. Traditional earthquake analysis has used the three orthographic views, however the use of 3D visualization for showing the destruction phenomenon can be considered as of highly importance. Taking this into consideration, we describe in this paper an attempt to visualize the destruction phenomenon of the Mid-Niigata prefecture Earthquake by using an Immersive Projection based Technology (IPT).

  The Visualization Society of Japan, 2005, 可視化情報学会誌, 25(1) (1), 121 - 122, Japanese

  [Refereed]


• 3d modeling and displaying system for volume communication

  Sakamoto, Naohisa, Kukimoto, Nobuyuki, Yasuhara, Yukio, Ebara, Yasuo, Koyamada, Koji

  2005, JSME International Journal Series B Fluids and Thermal Engineering, 48(2) (2), 247 - 251, English

  [Refereed]

  Scientific journal


• Hybrid hardware-accelerated image composition for sort-last parallel rendering on graphics clusters with commodity image compositor

  J Nonaka, N Kukimoto, N Sakamoto, H Hazama, Y Watashiba, XZ Liu, M Ogata, M Kanazawa, K Koyamada

  2004, IEEE SYMPOSIUM ON VOLUME VISUALIZATION AND GRAPHICS 2004, PROCEEDINGS, 17 - 24, English

  [Refereed]

  International conference proceedings


• View-independent Texture Representation for Omnidirectional Display.

  Naohisa Sakamoto, Jorji Nonaka, T. Takai, Koji Koyamada, T. Matsuyama

  IASTED/ACTA Press, 2003, Proceedings of the Sixth IASTED International Conference on Computer Graphics and Imaging, Honolulu, Hawaii, USA, August 13-15, 2003, 135 - 140

  [Refereed]

  International conference proceedings


• Parallel Image-Order Boundary-Projected Ray-Casting

  Nonaka Jorji, Watashiba Yasuhiro, Kukimoto Nobuyuki, Sakamoto Naohisa, Koyamada Koji, Iwashita Takeshi, Kanazawa Masanori

  2003, Proc. IASTED VIIP 2003, 779

  [Refereed]


• “A Technique for Specifying Region of Interest (ROI) in the Vector Field Based on 3D LIC”

  Koji Sakai, Koji Koyamada, Nao-Hisa Sakamoto, Koichi Matsuda, Akio Doi

  INSTITUTE OF IMAGE ELECTRONICS ENGINEERS OF JAPAN, 2003, Journal of the Institute of Image Electronics Engineers of Japan, 32(6) (6), 815 - 824, English

  [Refereed]

  Scientific journal


• A Streaming-based Technique for Volume Rendering of Large Datasets6.

  Yasuhiro Watashiba, Jorji Nonaka, Naohisa Sakamoto, Yasuo Ebara, Koji Koyamada, Masanori Kanazawa

  IASTED/ACTA Press, 2003, Proceedings of the Sixth IASTED International Conference on Computer Graphics and Imaging, Honolulu, Hawaii, USA, August 13-15, 2003, 187 - 192

  [Refereed]

  International conference proceedings


• Reconstruction of 3D objects by octree representation from multiple any views

  Sawa H, Sakamoto N, Iwanari E, Okada Y, Kanade T

  1999, Joho Shori Gakkai Kenkyu Hokoku, 99(29) (29), 33 - 40

  [Refereed]

  Scientific journal


• ポイントに基づくボリュームデータの生成および表示技術に関する研究

  坂本尚久

  坂本尚久(電気工学専攻), Japanese

  [Refereed]


• GPU Accelerated Particle Generation for Particle-Based Surface Rendering

  Miyachi Hideo, Katsuyama Kayoko, Tanaka Satoshi, Hasegawa Kyoko, Koyamada Koji, Sakamoto Naohisa

  [Refereed]


• Exploration of relationship between fishery and vortices

  Uenaka Takashi, Sakamoto Naohisa, Koyamada Koji

  [Refereed]


• Evaluation of Image Quality in Particle-based Volume Rendering

  Zhongming Ding, Kawamura Takuma, Sakamoto Naohisa, Koyamada Koji

  [Refereed]


• Boundary-Projection Technique for Efficient On-Demand Visualization of Large Data Sets

  Nonaka Jorji, Watashiba Yasuhiro, Kukimoto Nobuyuki, Sakamoto Naohisa, Koyamada Koji, Ebara Yasuo, Kanazawa Masanori

  [Refereed]


• A STREAMING-BASED TECHNIQUE FOR VOLUME RENDERING OF LARGE DATASETS Yasuhiro WATASHIBA1 Jorji NONAKA1

  SAKAMOTO Naohisa, EBARA Yasuo, KOYAMADA Koji, KANAZAWA Masanori

  [Refereed]

• 極端気象現象のアンサンブル分析のための可視化技術—Visualization Techniques for Ensemble Analysis of Extreme Weather Events—特集 大規模データの対話的可視化

  坂本 尚久

  東京 : 可視化情報学会, Oct. 2024, 可視化情報学会誌 = Journal of the Visualization Society of Japan, 44(171) (171), 巻頭1p,85 - 90, Japanese


• Efficient Camera Path Estimation for In-Situ Visualization Using Adaptive Time-step Sampling

  Adachi Kazuya, Iwata Ken, Matsushima Taisei, Sakamoto Naohisa, Nonaka Jorji, Bi Chongke

  For large-scale numerical simulations in which data I/O problems emerge as real challenges, there is a growing demand for in-situ visualization, which is expected to significantly reduce data I/O costs by performing visualization simultaneously with simulation. However, in-situ visualization outputs images rendered with pre-defined visualization parameters, thus causing lack of interactivity in visual exploration during the analysis phase. To solve this problem, this work focused on the smart in-situ visualization approach, which tries to automatically determine ‘when’ (time-step) and ‘where’ (viewpoint) to visualize during the simulation run. Although this approach can evaluate and visualize an optimal viewpoint from multiple viewpoints, the cost of evaluating the optimal viewpoint proportionately increases as the number of viewpoints increases. In this paper, we propose a method to reduce the cost of estimating the optimal viewpoint by evaluating and selecting important time domains as the simulation evolves. We also propose a method to increase the efficiency of estimating the camera movement path, which connects the obtained optimal viewpoints. In the experiments, the proposed method was applied to an oral airflow simulation, and its effectiveness was evaluated.

  Japan Society for Simulation Technology, 2024, Transaction of the Japan Society for Simulation Technology, 16(2) (2), 60 - 71, Japanese


• Simulation and Visualization

  SAKAMOTO Naohisa

  Scientific visualization is a key technology for efficiently obtaining new scientific knowledge and insights from a large amount of data using visual information. And it has developed mainly in the natural sciences, especially in the field of computational science, and has now widely spread to various academic fields, including not only science and engineering but also life science and social science. Recently, big data analysis and AI have increased the demand for the integration of data science and computational science to solve progressively complex scientific and social problems, and the data processed on high-performance computing environments is becoming increasingly diverse. Visualization and analysis techniques are becoming more important to obtain scientific knowledge that can be interpreted by humans from such a wide variety of large-scale data. In this paper, we review the past research on scientific visualization for numerical simulation, and discuss recent trends, challenges, and prospects for the future.

  The Visualization Society of Japan, Jan. 2023, Journal of the Visualization Society of Japan, 43(166) (166), 巻頭1p,3 - 6, Japanese


• 計測点群の半透明立体視における視覚ガイドとしてのエッジ強調可視化

  青井 大門, 長谷川 恭子, 李 亮, 坂野 雄一, 坂本 尚久, 田中 覚

  有形文化財の複雑構造の理解には，３次元計測点群に基づく半透明可視化が有効である．本研究は，これに立体視を組み合わせた半透明立体視により，半透明可視化に奥行き感を付与することを目的とする．しかし従来研究で，半透明立体視では奥行きが実際より過小評価されることが示されている. そこで，角や縁などの３次元エッジ部分を強調表示して視覚ガイドとして用いることで，線透視効果により奥行き認知を改善する．

  公益社団法人 精密工学会, 02 Mar. 2022, 精密工学会学術講演会講演論文集, 2022S, 158 - 159, Japanese


• Adaptive In-Situ Visualization Considering Spatio-temporal changes of Large-scale Numerical Simulation Results

  YAMAOKA Yoshiaki, HAYASHI Kengo, SAKAMOTO Naohisa, NONAKA Jorji, YOSHINAGA Tsukasa, NOZAKI Kazunori

  The Japan Society of Mechanical Engineers, 2019, The Proceedings of the Fluids engineering conference, 2019, IS-52, Japanese


• Lacrosse Vis: a visual analytics system for lacrosse players

  Shinsuke Imai, Yosuke Onoue, Naohisa Sakamoto, Nobuyuki Kukimoto, Koji Koyamada

  Apr. 2015, In Proc. of IEEE Pacific Visualization 2015 (Poster), English

  [Refereed]


• Visualization of ocean current effects for fishing ground formation

  Kyosuke FUTAMI, Yosuke ONOUE, Naohisa SAKAMOTO, Koji KOYAMADA, Kyoto University, Kyoto University, Kyoto University, Kyoto University

  コレクション : 国立国会図書館デジタルコレクション > 電子書籍・電子雑誌 > 学術機関 > 学協会

  日本流体力学会, Apr. 2015, ながれ : 日本流体力学会誌 = Nagare : journal of Japan Society of Fluid Mechanics, 34(2) (2), 83 - 86, Japanese


• Applying OpenGL Fusion to Fusion Visualization System

  宮地英生, 坂本尚久, 小山田耕二

  2015, 可視化情報学会誌, 35(Suppl.1) (Suppl.1)


• Text based visualization of evaluation structures using word clouds

  小澤 啓太, 尾上 洋介, 坂本 尚久

  可視化情報学会, 2015, 可視化情報学会誌 = ournal of the Visualization Society of Japan, 35(1) (1), 315 - 318, Japanese


• 漁場形成における海流の影響の可視化

  双見京介, 尾上洋介, 坂本尚久, 小山田耕二

  Dec. 2014, 日本流体力学会, 第28回数値流体力学シンポジウム講演論文集, Japanese


• 流体中を運動する球まわりの伝熱の可視化

  高見円仁, 趙コン, 坂本尚久, 小山田耕二

  Dec. 2014, 日本流体力学会, 第28回数値流体力学シンポジウム講演論文集, Japanese


• 大規模可視化向け並列 PBVR の考察

  ノナカ ジョルジ, 小野 謙二, 藤田 将洋, 坂本 尚久, 小山田 耕二

  Jul. 2014, 可視化情報学会, 第42回可視化情報シンポジウム講演論文集, Japanese


• Ensemble-Averaged Visualization for the Interannual Variability of Water Mass Dynamics for the Northwestern Pacific Near Japan

  Kun Zhao, Satoshi Nakada, Naohisa Sakamoto, Koji Koyamada

  Jun. 2014, In Proc. of The 16th International Symposium on Flow Visualization (ISFV16), English

  [Refereed]


• Visual Analytic System for Habitat Suitable Index Modeling of Neon Flying Squid with Visualization Tequnique

  Masashi Kushida, Takashi Uenaka, Naohisa Sakamoto, Koji Koyamada

  07 Mar. 2014, In Proc. of IEEE Pacific Visualization 2014 (Poster), English

  [Refereed]


• Ensemble-Averaged Visualization of the Water Mass Distribution for the Northwestern Pacific Ocean near Japan

  Kun Zhao, Satoshi Nakada, Naohisa Sakamoto, Koji Koyamada

  07 Mar. 2014, In Proc. of IEEE Pacific Visualization 2014 (Poster), English

  [Refereed]


• Visual Analysis Environment of Habitat Suitability Index Modeling for Stakeholders

  ONOUE Yosuke, SAKAMOTO Naohisa, KOYAMADA Koji

  In this study, we developed a visual analysis environment that allows various stakeholders to participate in habitat suitability index (HSI) modeling. HSI model quantitatively evaluates suitability of the earth environment for habitat of the target species. HSI model is developed by the specialists of biology with statistical analysis tools generally. However, participation of various stakeholders such as fishermen is important not only for improving accuracy of the model but also for formulating implicit knowledge of the target species. User interface of the visual analysis environment developed in this study was designed that allow various stakeholders to participate. Therefore, the visual analysis environment is optimized to run on the tablet devices. Stakeholders can develop an HSI model interactively with analyzing relation between ocean environment and fish catches using both geometric and variable views with our visual analysis environment.

  The Visualization Society of Japan, 2014, Journal of the Visualization Society of Japan, 34(135) (135), 28 - 33, Japanese


• 漁場と微小渦中心との関係の調査

  上中 隆史, 坂本 尚久, 小山田 耕二

  17 Jul. 2013, 可視化情報学会、第41回可視化情報シンポジウム講演論文集


• 確率論的アプローチによる非構造格子データ向け融合可視化技術

  坂本 尚久, 小山田 耕二

  17 Jul. 2013, 可視化情報学会、第41回可視化情報シンポジウム講演論文集, Japanese


• 漁場探索向け可視化分析システムの開発

  上中 隆史, 櫛田将史, 張馳, 坂本 尚久, 小山田 耕二

  17 Jul. 2013, 可視化情報学会、第41回可視化情報シンポジウム講演論文集, Japanese


• Applying Fusion visualization to blood hemorheological information including red blood cells

  宮地英生, 小山田耕二, 坂本尚久, 杉山和靖

  01 Jul. 2013, 可視化情報学会誌, 33(Suppl.1) (Suppl.1), 285‐286, Japanese


• ボリューム・サーフェイス融合可視化に関する研究

  宮地英生, 小山田耕二, 坂本尚久

  19 Jun. 2013, 計算工学講演会論文集(CD-ROM), 18, ROMBUNNO.C-8-5, Japanese


• 粒子ボリュームレンダリング法を使った大規模血流解析データの適応的可視化

  原大智, 坂本尚久, 小山田耕二, 宮地英生, 杉山和靖

  2013, 数値流体力学シンポジウム講演論文集(CD-ROM), 27th, ROMBUNNO.F03-2, Japanese


• 粒子ベースレンダリング法における粒子径の適応的決定―点群データ半透明表示への適用―

  坂本尚久, 小山田耕二, 田中覚

  2013, 数値流体力学シンポジウム講演論文集(CD-ROM), 27th, ROMBUNNO.F03-1, Japanese


• Exploration of relation between fishery spot and subtle vortex core

  上中 隆史, 坂本 尚久, 小山田 耕二

  可視化情報学会, 2013, 可視化情報学会誌 = ournal of the Visualization Society of Japan, 33(1) (1), 265 - 270, Japanese


• 海洋データ同化結果を使ったアカイカ好適生息域モデル作成支援可視化環境の開発

  櫛田将史, 上中隆史, 坂本尚久, 小山田耕二

  2013, 数値流体力学シンポジウム講演論文集(CD-ROM), 27th, ROMBUNNO.F03-5, Japanese


• PetaFlow - an example of communication and computational technologies with social impact

  A. Ancel, I. Assenmacher, K. Baba, J. Cisonni, Y. Fujiso, P. Gonalves, M. Imbert, K. Koyamada, P. Neyron, K. Nozaki, H. Ohsaki, A. C. Orgerie, X. Pelorson, B. Raffin, N. Sakamoto, E. Sakane, S. Shimojo, A. Van Hirtum, S. Wada

  2013, 2013 IEEE 37TH ANNUAL COMPUTER SOFTWARE AND APPLICATIONS CONFERENCE WORKSHOPS (COMPSACW), 703 - 708, English

  [Refereed]


• 超克イノベーション:復興を経て価値創造を加速する視覚協創支援環境

  小山田耕二, 小木哲朗, 清川清, 坂本尚久

  日本計算工学会, 29 May 2012, 計算工学講演会論文集(CD-ROM), 17, ROMBUNNO.B-7-1, Japanese


• Visualization and Analysis of Currents and Temperature Distribution Based on Ocean Data

  Zhang. C, Uenaka. T, Sakamoto.N, Koyamada.K

  2012, In Proceedings of International Conference on Simulation Technology (JSST2012), USB-Memory, English

  [Refereed]


• 色覚バリアフリーな円グラフの見やすさについて：Excelで描画できるグレースケール・デザイン活用の可能性

  持元江津子, 坂本尚久, 小山田耕二

  2012, 芸術科学会 NICOGRAPH 2012 (poster), 2012.11, Japanese

  [Refereed]


• 漁場探索・分布推定のための大規模海洋環境場データ向け可視化技術

  坂本尚久, 張馳, 上中隆史, 小山田耕二

  2012, 可視化情報学会、第40回可視化情報シンポジウム講演論文集, Japanese

  [Refereed]


• 海洋シミュレーションデータ向けビジュアルデータマイニング

  上中隆史, 張馳, 坂本尚久, 小山田耕二

  2012, 可視化情報学会、第40回可視化情報シンポジウム講演論文集, Japanese

  [Refereed]


• Excelによる海洋シュミレーション結果の可視化

  辻隆史, 坂本尚久, 小山田耕二

  2012, 芸術科学会 NICOGRAPH 2012 (short paper), 2012.11, Japanese

  [Refereed]


• F105 High Resolution Visualization with Particle-based Rendering

  Sakamoto Naohisa

  大量の情報を持っ可視化結果から重要な知見を見逃さないために、複雑な視覚情報をより分かりやすく提示することができる高解像度表示システムの活用が有効とされている。本稿では、液晶ディスプレイやプロジェクタなどを複数並べることによって、安価にスケーラブルな大規模表示環境を構築することができるタイルドデイスプレイ装置を利用した粒子べ一スレンダリング法による高解像度可視化技術について述べる。また、本技術を構造解析や流体解析などの数値シミュレーションデータの可視化に適用したいくつかの事例を示す。

  The Japan Society of Mechanical Engineers, 2012, The Proceedings of The Computational Mechanics Conference, 2012(0) (0), _F - 15_-_F-17_, Japanese


• サーフェイス・ボリューム融合可視化

  宮地英生, 小山田耕二, 坂本尚久

  2012, 数値流体力学シンポジウム講演論文集(CD-ROM), 26th, ROMBUNNO.A08-4, Japanese


• Block Division with Fast Cubic B-spline Reconstruction

  Zhao, Kun, Sakamoto, Naohisa, Koyamada, Koji

  2012, USBmemory. In Proceedings of International Conference on Simulation Technology (JSST2012)., English

  [Refereed]


• Stoachastic Approach for Integrated Rendering of Volumes and Semi-transparent surfaces

  Naohisa Sakamoto, Koji Koyamada

  2012, 2012 SC COMPANION: HIGH PERFORMANCE COMPUTING, NETWORKING, STORAGE AND ANALYSIS (SCC), 176 - 185, English

  [Refereed]


• Excelによる誤差可視化

  坂本尚久, 小山田耕二

  Oct. 2011, Proc JSST Annu Conf (CD-ROM), 30th, ROMBUNNO.P-3, Japanese


• Reduction of the Number of Generated Particles in Particle-based Volume Rendering

  MAEDA NAOYA, KUWANO HIROSHI, SAKAMOTO NAOHISA, KOYAMADA KOJI

  01 Jul. 2011, 可視化情報学会誌, 31(Suppl.1) (Suppl.1), 299 - 300, Japanese


• 広域分散計算機リソース利用の並列FEM/可視化クラウド

  奥田洋司, 飯田陽一郎, 小山田耕二, 坂本尚久, 上島豊, 石原典雄, 前田茂樹, 犬飼貴史

  25 May 2011, 計算工学講演会論文集(CD-ROM), 16, ROMBUNNO.F-1-1, Japanese


• 超大規模シミュレーションのためのグローバルコンピューティング

  馬場健一, 野崎一徳, 大崎博之, 坂本尚久, 坂根栄作, 小山田耕二, 下條真司

  28 Feb. 2011, 電子情報通信学会大会講演論文集, 2011, SS.72-SS.75, Japanese


• BT-4-3 Global Computing for Ultra Large-scale Scientific Simulation

  Baba Ken-ichi, Nozaki Kazunori, Ohsaki Hiroyuki, Sakamoto Naohisa, Sakane Eisaku, Koyamada Koji, Shimojo Shinji

  The Institute of Electronics, Information and Communication Engineers, 28 Feb. 2011, Proceedings of the IEICE General Conference, 2011(2) (2), "SS - 72"-"SS-75", Japanese


• Multi-dimensional Binning for Parallel Coordinates and Application to Large-scale CFD Results

  N.Sakamoto, T.Tanaka, K.Koyamad

  2011, Proceedings of the 11th Asian Symposium on Visualization (ASV11), English

  [Refereed]


• Development of Multi-touch User Interface for Tiled Display Visualization System

  J.Nishimura, N.Sakamoto, K.Koyamada

  2011, International Conference on Modeling and Simulation Technology (30th JSST Annual Conference -JSST2011- ), English

  [Refereed]


• 非構造格子テンソルボリュームデータ向け可視化技術とその応用

  郭嘉禎, 坂本尚久, 小山田耕二

  2011, 可視化情報学会 第39回可視化情報シンポジウム講演論文集, Japanese

  [Refereed]


• Visualization of Time-varying Irregular Volume Dataset Using Particle-based Volume Rendering

  西村 純, 坂本 尚久, 小山田 耕二

  可視化情報学会, 2011, 可視化情報学会誌, 31(1) (1), 295 - 298, Japanese


• “粒子ボリュームレンダリングにおける棄却法による粒子生成”

  前田直哉, 河村拓馬, 坂本尚久, 小山田耕二

  2011, 可視化情報学会第39 回可視化情報シンポジウム講演論文集，2011, Japanese

  [Refereed]


• High Quality Sampling Technique of PBVR for Irregular Hexahedral Mesh Data

  Kawamura Takuma, Koyamada Koji, Sakamoto Naohisa, Tanaka Satoshi

    In this paper, we propose a high quality sampling technique of Particle-based volume rendering (PBVR) which is suitable for handling a complicated ultra-scale volume dataset composed of multiple sub-volumes. In PBVR, we estimate a number of particles by integrating a particle density function derived by an opacity transfer function and generate particles by using a stochastic technique. Previously, we approximated the density function using a uniform function in a volume cell which may result in an inaccurate estimation of the particle number and a sampling failure when we deal with a transfer function with drastic changes. To solve the problem, we employ a Gibbs sampling technique and apply the proposed technique to several hexahedral unstructured volume datasets in order to confirm the effectiveness.
  

  Japan Society for Simulation Technology, 2011, Transaction of the Japan Society for Simulation Technology, 3(3) (3), 48 - 59, English


• ‶Static Visualization of Dynamical Plasma Collision”

  N.Kawamoto, Y.Hatanaka, K.Hasegawa, S.Nakata, S.Tanaka, N.Sakamoto, K.Koyamada, M.Osada, K.Tanaka

  2011, Proceedings of the 11th Asian Symposium on Visualization (ASV11), 2011, English

  [Refereed]


• ‶Large-scale Data Exploration with Clustered Parallel Coordinates”

  C.Zhang, N.Sakamoto, K.Koyamada

  2011, International Conference on Modeling and Simulation Technology (30th JSST Annual Conference -JSST2011-), 2011, English

  [Refereed]


• ‶Visualization of Plasma Plume Collisions Using Fused Volume Data”

  N.Kawamoto, Y.Hatanaka, T.Yamamoto, K.Hasegawa, S.Nakata, S.Tanaka, N.Sakamoto, K.Koyamada, S.Misaki, K.Tanaka

  2011, Proceedings of the Asia Simulation Conference 2011 (AsiaSim2011), 2011, English

  [Refereed]


• ‶Tiled Display Visualization System with Multi-touch Control”

  J. Nishimura, N.Sakamoto, K.Koyamada

  2011, Proceedings of the Asia Simulation Conference 2011 (AsiaSim2011), 2011, English

  [Refereed]


• ‶Clustered Parallel Coordinates with High-Speed k-Means Algorithm and Outof- Core Feature

  C.Zhang, N.Sakamoto, K.Koyamada

  2011, Proceedings of the Asia Simulation Conference 2011 (AsiaSim2012), 2011, English

  [Refereed]


• Peta-flow computing: Vision and challenges

  Hiroyuki Ohsaki, Kazunori Nozaki, Ken'ichi Baba, Eisaku Sakane, Naohisa Sakamoto, Kohji Koyamada, Shinji Shimojo

  2011, Proceedings - 11th IEEE/IPSJ International Symposium on Applications and the Internet, SAINT 2011, 256 - 259, English

  [Refereed]


• Surface-surface and surface-volume fusion using the particle-based surface rendering

  SHIMOKUBO YOSHIYUKI, KANEKO TOMONORI, TAMAKI YASUHIRO, NAKATA SUSUMU, HASEGAWA KYOKO, SAKAMOTO NAOHISA, KOYAMADA KOJI, TANAKA SATOSHI

  15 Oct. 2010, 可視化情報学会誌, 30(Suppl.2) (Suppl.2), 221 - 222, Japanese


• Performance Improvement of Hierarchical Response Surface Methodology Using an Automatic Estimation of Dividing Regions

  TANAKA TEPPEI, SAKAMOTO NAOHISA, KOYAMADA KOJI

  01 Jul. 2010, 可視化情報学会誌, 30(Suppl.1) (Suppl.1), 291 - 292, Japanese


• Particle modeling for high resolution rendering of large-scale volume data

  KUWANO HIROSHI, MAEDA NAOYA, KAWAMURA TAKUMA, SAKAMOTO NAOHISA, KOYAMADA KOJI

  可視化情報学会, 01 Jul. 2010, 可視化情報学会誌, 30(Suppl.1) (Suppl.1), 285 - 290, Japanese


• 粒子ベースボリュームレンダリング法のための不規則六面体メッシュ向けハイクオリティーサンプリング手法

  河村拓馬, 坂本尚久, 小山田耕二

  19 Jun. 2010, 日本シミュレーション学会大会発表論文集, 29th, 343 - 346, Japanese


• 大規模宇宙シミュレーション結果のための対話的可視化手法

  西村純, 河村拓馬, 矢作日出樹, 坂本尚久, 小山田耕二

  19 Jun. 2010, 日本シミュレーション学会大会発表論文集, 29th, 347 - 350, Japanese


• 階層型応答曲面法

  田中哲平, 坂本尚久, 小山田耕二

  In this paper, we propose a optimization technique that we call a hierarchical Response Surface Methodology (hRSM). Since it is difficult to approximate a complex parameter space by using a single quadratic polynomial surface, hRSM adopted a recursive sub division technique and used the coefficient of multiple determinations (R²) to represent the response surface in each sub space for the threshold of the sub division. We verified the accuracy of hRSM by using some well-known benchmark functions that a reused in optimization. We confirmed the effectiveness of hRSM by applying it to bio-simulation's parameter estimation.

  Japan Society for Simulation Technology, 15 Mar. 2010, 日本シミュレーション学会論文誌, 2(1) (1), 23 - 31, Japanese


• Hierarchical Response Surface Methodology

  田中 哲平, 坂本 尚久, 小山田 耕二

  資料形態 : テキストデータ プレーンテキスト

  日鉄技術情報センタ-, Mar. 2010, Journal of the Japan Society for Simulation Technology, 29(1) (1), 23 - 31, Japanese


• Integration of Semi-transparent Polygons for Sorting-free Volume Rendering

  Naohisa Sakamoto, Takuma Kawamura, Koji Koyamada

  2010, Poster Proceedings of IEEE Pacific Visualization Symposium 2010, pp.5-6, English

  [Refereed]


• An Exploration of Multivariate Time-Varying Volume Datasets Using Volumetric Parallel Coordinates

  Shiori Yasuoka, Naohisa Sakamoto, Koji Koyamada

  2010, Proceedings of the 7th EUROSIM Congress on Modelling and Simulation, CD-ROM, 2010, English

  [Refereed]


• 細胞死に伴う小胞形成の時系列的変動の解析

  酒巻和弘, 坂本尚久, 河村拓馬, 千場久美子, 澤崎達也, 小山田耕二

  (公社)日本生化学会, 2010, 生化学, 83回・33回, ROMBUNNO.2P-0245 - 0245, Japanese


• Parallelization of particle based volume rendering on tiled display wall

  Hideo Miyachi, Hironori Shigeta, Kiyoshi Kiyokawa, Hiroshi Kuwano, Naohisa Sakamoto, Koji Koyamada

  IEEE Computer Society, 2010, Proceedings - 13th International Conference on Network-Based Information Systems, NBiS 2010, 435 - 438, English

  [Refereed]


• Petaflow - A project towards information and communication technologies in society

  Paulo Gonçalves, Xavier Grandchampy, Xavier Pelorsony, Bruno Raffinz, Annemie Van Hirtumy, Pascale Vicat-Blanc, Ken-Ichi Baba, Julien Cisonni, Yasuo Ebara, Kazunori Nozaki, Hiroyuki Ohsaki, Shigeo Wada, Takuma Kawamura, Kohji Koyamada, Eisaku Sakanez, Naohisa Sakamoto, Shinji Shimojoy

  2010, Proceedings - 2010 10th Annual International Symposium on Applications and the Internet, SAINT 2010, 347 - 350, English

  [Refereed]


• Effective Remote Visualization for Large-scale Volume Data by Particle-based Volume Rendering

  EBARA Yasuo, SAKURAI Ken-ichi, SONE Hideaki, SAKAMOTO Naohisa, KOYAMADA Koji

  The demand for the remote visualization has rising in order to construct remote collaborative work environment for working common issues by sharing visualization results of large-scale volmue data between remote places at real time, although the effective technique has not established. In this paper, we have proposed the remote visualization technique using particle-based volume rendering to solve the issues of the bottleneck by the composite processing in distributed visualization. In addition, we have implemented the parallel transmission by TCP as effective transmission of a large amount of data generated by dialogical processing via WAN. From the results of experiments on WAN, we have proved the parallel effect to display a result image of volume data by 512³ grids and the processing time become short by increasing the number of slave in server-side. Moreover, we have realized the reduction of data transmission time by increasing the number of TCP stream.

  画像電子学会, 25 Sep. 2009, The Journal of the Institute of Image Electronics Engineers of Japan, 38(5) (5), 753 - 761, Japanese


• タイルドディスプレイを用いた大規模ボリューム可視化システム向け3次元ユーザインタフェースの提案

  繁田浩功, 桑野浩, 河村拓馬, 坂本尚久, 野崎一徳, 江原康生, 清川清, 小山田耕二, 竹村治雄

  09 Sep. 2009, 日本バーチャルリアリティ学会大会論文集(CD-ROM), 14th, ROMBUNNO.2B3-5, Japanese


• <高校生のページ> 人間回帰としての可視化技術

  小山田 耕二, 坂本 尚久

  京都大学電気関係教室・洛友会, Sep. 2009, Cue : 京都大学電気関係教室技術情報誌, 22(22) (22), 54 - 59, Japanese


• Fundamentals of Visualization Programming : Large-scale Distributed Volume Rendering with Tiled-Display Wall

  SAKAMOTO Naohisa, KOYAMADA Koji

  資料形態 : テキストデータ プレーンテキスト

  日本計算工学会, 31 Jul. 2009, Journal of the Japan Society for Computational Engineering and Science, 14(3) (3), 2130 - 2137, Japanese


• Visual Data Mining Environment for Japanese Cultural Information

  KOYAMADA Koji, SAKAMOTO Naohisa

  01 Jul. 2009, 可視化情報学会誌, 29(1) (1), 105 - 106, Japanese


• Development of a Design Support System For Photonic Crystal of the Optical Buffer Memory Using Information Visualization

  TANAKA Teppei, YAMASAKI Akira, SAKAMOTO Naohisa, KOYAMADA Koji

  The Visualization Society of Japan, 01 Jul. 2009, Journal of the Visualization Society of Japan, 29(1) (1), 101 - 104, Japanese


• High-resolution Visualization System of Large-scale irregular Volumes on a Tiled Display Wall

  KOYAMADA Koji, SAKAMOTO Naohisa, KUWANO Hiroshi, KAWAMURA Takuma

  The Visualization Society of Japan, 01 Jul. 2009, Journal of the Visualization Society of Japan, 29(1) (1), 43 - 48, Japanese


• Linear gradient sampling for particle-based volume rendering

  KAWAMURA Takuma, SAKAMOTO Naohisa, KOYAMADA Koji

  11 Jun. 2009, 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム, 28, 235 - 238, Japanese


• Fundamentals of Visualization Programming : Acceleration of Particle-based Volume Rendering with GPU

  SAKAMOTO Naohisa, KOYAMADA Koji

  資料形態 : テキストデータ プレーンテキスト

  日本計算工学会, 30 Apr. 2009, Journal of the Japan Society for Computational Engineering and Science, 14(2) (2), 2062 - 2069, Japanese


• Fundamentals of Visualization Programing : Particle-based Volume Rendering

  SAKAMOTO Naohisa, KOYAMADA Koji

  資料形態 : テキストデータ プレーンテキスト

  日本計算工学会, 31 Jan. 2009, Journal of the Japan Society for Computational Engineering and Science, 14(1) (1), 2008 - 2014, Japanese


• A High Quality Sampling Technique for Particle-based Volume Rendering

  Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  2009, IEEE Visualization'09 (Poster), English

  [Refereed]


• Effective Remote Visualization for Large-scale Volume Data by Particle-based Volume Rendering

  EBARA Yasuo, SAKURAI Ken-ichi, SONE Hideaki, SAKAMOTO Naohisa, KOYAMADA Koji

  The demand for the remote visualization has rising in order to construct remote collaborative work environment for working common issues by sharing visualization results of large-scale volmue data between remote places at real time, although the effective technique has not established. In this paper, we have proposed the remote visualization technique using particle-based volume rendering to solve the issues of the bottleneck by the composite processing in distributed visualization. In addition, we have implemented the parallel transmission by TCP as effective transmission of a large amount of data generated by dialogical processing via WAN. From the results of experiments on WAN, we have proved the parallel effect to display a result image of volume data by 512³ grids and the processing time become short by increasing the number of slave in server-side. Moreover, we have realized the reduction of data transmission time by increasing the number of TCP stream.

  The Institute of Image Electronics Engineers of Japan, 2009, The Journal of the Institute of Image Electronics Engineers of Japan, 38(5) (5), 753 - 761, Japanese


• 粒子ベースボリュームレンダリングのための線型勾配サンプリング法

  河村拓馬, 坂本尚久, 小山田耕二

  2009, 第28回日本シミュレーション学会大会、2009, Japanese

  [Refereed]


• Visual Data Mining Environment for Japanese Cultural Information

  KOYAMADA Koii, SAKAMOTO Naohisa

  The Visualization Society of Japan, 2009, Journal of the Visualization Society of Japan, 29(1) (1), 105 - 105, Japanese


• Hierarchical Response Surface Methodology

  Tanaka Teppei, Sakamoto Naohisa, Koyamada Koji

  In this paper, we propose a optimization technique that we call a hierarchical Response Surface Methodology (hRSM). Since it is difficult to approximate a complex parameter space by using a single quadratic polynomial surface, hRSM adopted a recursive sub division technique and used the coefficient of multiple determinations (R²) to represent the response surface in each sub space for the threshold of the sub division. We verified the accuracy of hRSM by using some well-known benchmark functions that a reused in optimization. We confirmed the effectiveness of hRSM by applying it to bio-simulation's parameter estimation.

  Japan Society for Simulation Technology, 2009, Transaction of the Japan Society for Simulation Technology, 2(1) (1), 23 - 31, Japanese


• Streamline Visualization Technique for Sub-volume Based CFD Results

  Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  2009, Asia Simulation Conference 2009 (Poster), 2009, English

  [Refereed]


• Visualization of Adaptive Mesh Refinement Data Using Particle-based Volume Rendering

  Jun Nishimura, Hiroshi Kuwano, Takuma Kawamura, Naohisa Sakamoto, Kaji Koyamada

  2009, Asia Simulation Conference 2009 (Poster), 2009, English

  [Refereed]


• An Efficient Rectangle Packing for Improving the Performance of HeiankyoView

  Hayakawa, Akira, Itoh, Takayuki, Koyamada, Koji, Sakamoto, Naohisa

  2009, Proc. of NICOGRAPH International 2009, CD-ROM, 2009, English

  [Refereed]


• Collaborative Visualization System for Complex CFD Results on a Tiled Display Wall

  Hiroshi Kuwano, Takuma Kawamura, Naohisa Sakamoto, Koji Koyamada

  2009, Proc. of 3rd International Workshop on Process Tomography, 2009, English

  [Refereed]


• “Spatio-Temporal Analysis of Time-Varying Multivariate Volume Dataset Using Volumetric Parallel Coordinates”

  Shiori Yasuoka, Naohisa Sakamoto, Koji Koyamada

  2009, 坂本 尚久（特定助教）【学会発表】 （査読付国際会議） Asia Simulation Conference 2009 (Poster), 2009 Best Poster Award, English

  [Refereed]


• Takuma Kawamura, Koji Koyamada, Naohisa Sakamoto

  Takuma Kawamura, Koji Koyamada, Naohisa Sakamoto

  2009, 小山田耕二（教授）【学会発表】 （査読付国際会議） Proc. of 2009 Workshop on Visualization Applications, 2009, English

  [Refereed]


• Sorting-free pre-integrated projected tetrahedra

  Naohisa Sakamoto, Takuma Kawamura, Hiroshi Kuwano, Koji Koyamada

  2009, Proceedings of the 2009 Workshop on Ultrascale Visualization, UltraVis '09, 11 - 18, English

  [Refereed]


• Interactive hierarchical RSM applied to parameter optimization of photonic crystal nanocavities

  Teppei Tanaka, Akira Yamasaki, Koji Koyamada, Naohisa Sakamoto

  2009, Digest of Technical Papers - IEEE International Conference on Consumer Electronics, 13th Vol.2, 718 - 722, English

  [Refereed]


• Fundamentals of Visualization Programing-FEM and Volume Rendering

  SAKAMOTO Naohisa, KOYAMADA Koji

  資料形態 : テキストデータ プレーンテキスト

  日本計算工学会, 31 Oct. 2008, Journal of the Japan Society for Computational Engineering and Science, 13(4) (4), 1934 - 1940, Japanese


• 細胞死(アポトーシス)に伴う細胞形態の時系列的変動の解析

  酒巻 和弘, 河村 拓馬, 坂本 尚久, 小山田 耕二

  30 Oct. 2008, バイオイメージング, 17(2) (2), 222 - 222, Japanese


• A Construction of real-time visualization system using a sensor network using CAVE system

  SEGAWA Norihisa, SAKAMOTO Naohisa, KOYAMADA Koji, SAWAMOTO Jun

  We report the system which acquires the data from sensor netowork and visualizes the data on real time by three dimensions on a computer. It becomes possible for this system to make a user make the measurement data on space intuitive.

  The Institute of Electronics, Information and Communication Engineers, 15 Oct. 2008, IEICE technical report, 108(252) (252), 7 - 11, Japanese


• Spatiotemporal Analysis of Morphological Changes in Cell Death Using Multiple Volume Visualization

  KAWAMURA Takuma, SAKAMOTO Naohisa, KIOKA Miki, SAKAMAKI Kazuhiro, KOYAMADA Koji

  The Visualization Society of Japan, 15 Sep. 2008, 可視化情報学会誌, 28(2) (2), 159 - 160, Japanese


• 粒子ベースボリュームレンダリングを用いた大規模遠隔可視化の評価(3.2 第6回情報シナジー研究会, 3. 研究活動報告)

  櫻井 健一, 坂本 尚久, 江原 康生, 曽根 秀昭, 小山田 耕二

  type:紀要類 (bulletin)

  東北大学サイバーサイエンスセンター, Jul. 2008, 年報, 7(7) (7), 94 - 99, Japanese


• 新素材の精密研削加工(第2報)

  大橋利仙, 赤羽輝夫, 本田竜未, 蓮田裕一, 鈴木康史, 加藤隆浩, 坂本尚久, 廻谷諒

  Jul. 2008, 栃木県産業技術センター研究報告, (5) (5), 1 - 5, Japanese


• Similar Judgment Method of Brain Neural Pathway Using DT-MRI

  WATASHIBA Yasuhiro, SAKAMOTO Naohisa, SAKAI Koji, KOYAMADA Koji, DOI Akio, KANAZAWA Masanori

  01 Jul. 2008, Kashika Joho, 28(1) (1), 85 - 86, Japanese


• Improvement of image quality for particle-based volume rendering

  KAWAMURA Takuma, SAKAMOTO Naohisa, KOYAMADA Koji

  19 Jun. 2008, 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム, 27, 315 - 318, Japanese


• Distributed Visualization of Huge Irregular Grid Data by Particle Based Volume Rendering

  KUWANO Hiroshi, KAWAMURA Takuma, YAMASAKI Akira, SAKAMOTO Naohisa, EBARA Yasuo, KOYAMADA Koji

  19 Jun. 2008, 日本シミュレーション学会大会発表論文集, 27, 311 - 314, Japanese


• Hierarchical Response Surface Methodology

  TANAKA Teppei, SAKAMOTO Naohisa, KOYAMADA Koji

  In this paper, we propose a optimization technique that we call a hierarchical Response Surface Methodology (hRSM). Since it is difficult to approximate a complex parameter space by using a single quadratic polynomial surface, hRSM adopted a recursive sub division technique and used the coefficient of multiple determinations (R²) to represent the response surface in each sub space for the threshold of the sub division. We verified the accuracy of hRSM by using some well-known benchmark functions that a reused in optimization. We confirmed the effectiveness of hRSM by applying it to bio-simulation's parameter estimation.

  Japan Society for Simulation Technology, 19 Jun. 2008, 日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム, 27(1) (1), 283 - 286, Japanese


• Grid-Independent Monte Carlo Sampling with SubPixel Algorithm for Volume Visualization

  MIYAMOTO Junko, SAKAMOTO Naohisa, KOYAMADA Koji, TANAKA Satoshi

  19 Jun. 2008, 日本シミュレーション学会大会発表論文集, 27, 307 - 310, Japanese


• 高度遠隔コラボレーション支援環境とシミュレーション シミュレーションとボリューム可視化

  坂本尚久, 小山田耕二

  資料形態 : テキストデータ プレーンテキスト コレクション : 国立国会図書館デジタルコレクション > 電子書籍・電子雑誌 > 学術機関 > 学協会 コレクション : 国立国会図書館デジタルコレクション > デジタル化資料 > 雑誌

  日本シミュレーション学会, 15 Mar. 2008, シミュレーション, 27(1) (1), 8 - 15, Japanese


• Simulation and Volume Visualization

  SAKAMOTO Naohisa, KOYAMADA Koji

  資料形態 : テキストデータ プレーンテキスト

  日本シミュレーション学会, 15 Mar. 2008, Journal of the Japan Society for Simulation Technology, 27(1) (1), 8 - 15, Japanese


• Distributed Particle-based Volume Rendering for Irregular Volumes

  Naohisa Sakamoto, Hiroshi Kuwano, Takuma Kawamura, Yasuo Ebara, Koji Koyamada, Kazunori Nozaki

  2008, The first International Workshop on Super Visualization (IWSV08), CD-ROM, English

  [Refereed]


• A Stochastic Approach for Rendering Irregular Volumes

  Takuma Kawamura, Naohisa Sakamoto, Akira Yamasaki, Koji Koyamada

  2008, Poster Proceedings of IEEE Pacific Visualization Symposium 2008 (PacificVis 2008), pp.31-32, English

  [Refereed]


• 粒子ベースボリュームレンダリングを用いた大規模非構造 データ向け分散可視化システムの実験的検証

  桑野浩, 山崎晃, 坂本尚久, 江原康弘, 小山田耕二

  2008, 第5 回先端的ネットワーク& コンピューティングテクノロジワークショップ,2008., Japanese

  [Refereed]


• 粒子ベースボリュームレンダリングを用いた大規模遠隔可視化の評価

  櫻井健一, 坂本尚久, 江原康生, 曽根秀昭, 小山田耕二

  2008, 第6 回東北大学情報シナジー機構情報シナジー研究会, 2008., Japanese

  [Refereed]


• Particle density estimation for particle-based volume rendering Application for the large irregular volume datasets:Application for the large irregular volume datasets

  Kawamura Takuma, Sakamoto Naohisa, Yamasaki Akira, Koyamada Koji

  In this paper, we describe a stochastic approach for previewing large irregular volume datasets with small memory resources. It is well known that the memory bandwidth consumed by visibility sorting becomes the limiting factor when carrying out volume rendering of large irregular volume datasets. To solve this problem, previous techniques without visibility sorting ignored absorption and emission in their optical models. Our technique represents a given irregular volume dataset as a set of opaque, emissive particles whose size is sufficiently small with respect to the pixel size. We applied our proposed technique to a volume composed of about 1G tetrahedral cells to confirm its effectiveness.

  The Visualization Society of Japan, 2008, Transactions of the Visualization Society of Japan, 28(11) (11), 69 - 77, Japanese


• Particle density estimation for particle-based volume rendering Application for the large irregular volume datasets

  Kawamura, Takuma, Sakamoto, Naohisa, Yamasaki, Akira, Koyamada, Koji

  In this paper, we describe a stochastic approach for previewing large irregular volume datasets with small memory resources. It is well known that the memory bandwidth consumed by visibility sorting becomes the limiting factor when carrying out volume rendering of large irregular volume datasets. To solve this problem, previous techniques without visibility sorting ignored absorption and emission in their optical models. Our technique represents a given irregular volume dataset as a set of opaque, emissive particles whose size is sufficiently small with respect to the pixel size. We applied our proposed technique to a volume composed of about 1G tetrahedral cells to confirm its effectiveness.

  The Visualization Society of Japan, 2008, Transaction of the Visualization Society of Japan, 28(11) (11), 69 - 77, Japanese

  [Refereed]


• Paticle-based Volume Rendering and its applications

  KOYAMADA KOJI, SAKAMOTO NAOHISA

  2008, 流体力学講演会/航空宇宙数値シミュレーション技術シンポジウム講演集, 40th-2008, 159 - 162, Japanese


• Spatiotemporal Analysis of Morphological Changes in Cell Death Using Multiple Volume Visualization

  KAWAMURA Takuma, SAKAMOTO Naohisa, KIOKA Miki, SAKAMAKI Kazuhiro, KOYAMADA Koji

  The Visualization Society of Japan, 2008, Journal of the Visualization Society of Japan, 28(2) (2), 1159 - 1159, Japanese


• DT-MRI を使った脳神経繊維の類似度判定法

  渡場康弘, 坂本尚久, 酒井晃二, 小山田耕二, 土井章男, 金澤正憲

  2008, 可視化情報学会第36 回可視化情報シンポジウム講演論文集、pp. 85-86、2008, Japanese

  [Refereed]


• A Particle Modeling for Rendering Irregular Volumes

  Koji Koyamada, Naohisa Sakamoto, Satoshi Tanaka

  2008, 2008 UKSIM TENTH INTERNATIONAL CONFERENCE ON COMPUTER MODELING AND SIMULATION, 372 - 377, English

  [Refereed]


• Development of the Support System for Estimation of Fault Plane with Hypocenter Data

  YASUHARA Yukio, SAKAMOTO Naohisa, EBARA Yasuo, KATAO Hiroshi, KOYAMADA Koji

  Effective data visualization techniques are required in order to support efficient earthquake analysis. So far, earthquake analysis experts have only been able to imagine 3D structures from typical 2D expressions. However, we consider that experts would be able to understand 3D structures more acculately and efficiently by providing them with an intuitive and interactive 3D display system. We focused on immersive projection technology (IPT) systems, more specifically on the CAVE system, to develop an effective support system for earthquake data analysis. We also developed an IPT oriented bimanual input based control interface for the support system to enable intuitive user interaction with the 3D display. In addition, we implemented a support tool for estimating fault planes in the earthquake phenomenon using the Ordinary Kriging method.

  日本シミュレーション学会, 15 Dec. 2007, Journal of the Japan Society for Simulation Technology, 26(4) (4), 212 - 218, Japanese


• Development of the Support System for Estimation of Fault Plane with Hypocenter Data.

  YASUHARA YUKIO, SAKAMOTO NAOHISA, EBARA YASUO, KATAO HIROSHI, KOYAMADA KOJI

  15 Dec. 2007, シミュレーション, 26(4) (4), 212 - 218, Japanese


• Study on Multi-Points Remote Communication System in Tiled Displays Environment

  SAWAFUJI Makoto, SAKAMOTO Naohisa, EBARA Yasuo, KOYAMADA Koji

  It is difficult to conduct smooth Communication for each participant by sense of incompatibility in remote communication with the videoconferencing between multi-points. We consider that it cases the lack of Mutual Gaze-Awareness which is indispensable by communication in the real world lack by watching the display where expression of other participant was projected via network. In this research, we have constructed multi-pint remote communication system with tiled displays that is able to display many video images on a large screen and enable effective video transmission automatically by the estimation of the face direction with image recognition technology.

  Information Processing Society of Japan (IPSJ), 03 Sep. 2007, IPSJ SIG Notes. CVIM, 160(87) (87), 1 - 6, Japanese


• Study on Multi-Points Remote Communication System in Tiled Displays Environment

  澤藤 誠, 坂本 尚久, 江原 康生, 小山田耕二

  多地点でのビデオ会議を用いた遠隔コミュニケーションの際、話したい方の相手とうまくコミュニケーションをとれないといった違和感の問題が生じる。これはネットワーク経由で相手の顔が映し出されたディスプレイを見つめるだけでは、実世界でもコミュニケーションに不可欠なMutual Gaze-Awareness が欠落しているためである。本研究では大画面上に多数の映像画面が表示可能なタイルドディスプレイを用い、画像認識技術を用いた顔方向推定によって効果的な送信映像の自動切換を行う多地点遠隔コミュニケーションシステムを構築した。It is difficult to conduct smooth Communication for each participant by sense of incompatibility in remote communication with the videoconferencing between multi-points. We consider that it cases the lack of Mutual Gaze-Awareness which is indispensable by communication in the real world lack by watching the display where expression of other participant was projected via network. In this research, we have constructed multi-pint remote communication system with tiled

  一般社団法人情報処理学会, 03 Sep. 2007, 情報処理学会研究報告コンピュータビジョンとイメージメディア（CVIM）, 2007(87) (87), 1 - 6, Japanese


• Study on Multi-Points Remote Communication System in Tiled Displays Environment

  SAWAFUJI Makoto, SAKAMOTO Naohisa, EBARA Yasuo, KOYAMADA Koji

  It is difficult to conduct smooth Communication for each participant by sense of incompatibility in remote communication with the videoconferencing between multi-points. We consider that it cases the lack of Mutual Gaze-Awareness which is indispensable by communication in the real world lack by watching the display where expression of other participant was projected via network. In this research, we have constructed multi-pint remote communication system with tiled displays that is able to display many video images on a large screen and enable effective video transmission automatically by the estimation of the face direction with image recognition technology.

  The Institute of Electronics, Information and Communication Engineers, 27 Aug. 2007, IEICE technical report, 107(206) (206), 1 - 6, Japanese


• Study on Multi-Points Remote Communication System in Tiled Displays Environment

  SAWAFUJI Makoto, SAKAMOTO Naohisa, EBARA Yasuo, KOYAMADA Koji

  It is difficult to conduct smooth Communication for each participant by sense of incompatibility in remote communication with the videoconferencing between multi-points. We consider that it cases the lack of Mutual Gaze-Awareness which is indispensable by communication in the real world lack by watching the display where expression of other participant was projected via network. In this research, we have constructed multi-pint remote communication system with tiled displays that is able to display many video images on a large screen and enable effective video transmission automatically by the estimation of the face direction with image recognition technology.

  The Institute of Electronics, Information and Communication Engineers, 27 Aug. 2007, IEICE technical report, 107(207) (207), 1 - 6, Japanese


• Volume Rendering for Multiple Volume Datasets Using Particle Fusion

  KUWANO Hiroshi, SAKAMOTO Naohisa, KOYAMADA Koji, SAITO Ayumu, KIMURA Akinori, TANAKA Satoshi

  We present a novel technique for rendering multiple volume datasets using particles as rendering primitives. In previous techniques, a data-intermixing process was required since the function is multi-valued. Although weighting values should be determined in this process, there are no specific guidelines for doing so. In contrast, our technique does not require data intermixing since we represent a volume dataset as a set of tiny, opaque particles which are generated with a stochastic technique. We applied our technique to volume datasets used for radiotherapy treatment planning in order to confirm its effectiveness.

  The Visualization Society of Japan, 01 Jul. 2007, Journal of the Visualization Society of Japan, 27(1) (1), 43 - 44, Japanese


• Particle-Based Volume Rendering for Irregular Grid

  KAWAMURA Takuma, SAKAMOTO Naohisa, NONAKA Joji, KOYAMADA Koji

  21 Jun. 2007, 日本シミュレーション学会大会発表論文集, 26, 333 - 336, Japanese


• A Scence Graph based Visualization System for Handling Multiple Visualization Pipelines

  Y. Yasuhara, N. Sakamoto, J. Nonaka, K. Koyamada

  2007, Asia-Pacific Symposium on Visualisation (APVIS 2007), Poster, English

  [Refereed]


• 粒子ベースボリュームレンダリングによる大規模非構造データ向け分散可視化

  桑野浩, 山崎晃, 坂本尚久, 江原康弘, 小山田耕二

  2007, 第5回テレイマージョン技術研究会, Japanese

  [Refereed]


• 平安京ビューを用いた階層型応答曲面法による対話的最適化システム

  田中哲平, 坂本尚久, 小山田耕二

  2007, 可視化情報学会 第１回ビジュアルデータマイニング研究会, Japanese

  [Refereed]


• Particle-based Volume Rendering

  SAKAMOTO Naohisa, KOYAMADA Koji

  In this paper, we present a novel point-based volume rendering technique based on particle generation from user-specified transfer function. In our presented technique, a set of tiny particles is generated from a given 3D scalar field. This particle generation process is based on a user-specified transfer function and rejection method. These particles are then projected onto the image plane to generate the final image. The main characteristic of our proposed technique is that particle projection order is independent and unfixed since the transparency values of particles are not taken into account. Therefore, only the depth-order comparison of particles is required during the particle projection stage and this greatly facilitates the parallel processing. When the quantity of projected particles is small, for instance one per pixel, it becomes difficult to reproduce the semi-transparent appearance which is the main characteristic of volume rendering. To overcome this problem, sub-sampling is applied in order to project several particles to a given pixel and the final color is obtained by averaging these partial color values.
  

  The Visualization Society of Japan, 2007, Transactions of the Visualization Society of Japan, 27(2) (2), 7 - 14, Japanese


• 統合可視化基盤KVS のテレイマーシブ環境への対応

  坂本尚久, 江原康生, 小山田耕二

  2007, 日本バーチャルリアリティ学会 第4 回テレイマージョン技術研究会, 2007., Japanese

  [Refereed]


• An stochastic approach for rendering a large volume dataset

  Koyamada Koji, Sakamoto Naohisa, Tanaka Satoshi

  In this paper, we describe an atomic approach for rendering irregular volume datasets. It is well known that the memory bandwidth consumed by visibility sorting becomes the limiting factor when carrying out volume rendering of large irregular volume datasets. To solve this problem, previous techniques without visibility sorting ignored absorption and emission in their optical models. Our technique represents a given irregular volume dataset as a set of opaque, emissive particles whose size is sufficiently small with respect to the pixel size. We applied our proposed technique to a volume composed of about 1G tetrahedral cells to confirm its effectiveness.

  Transdisciplinary Federation of Science and Technology, 2007, Proceedings of the Conference of Transdisciplinary Federation of Science and Technology, 2007(0) (0), 132 - 132, Japanese


• Volume Rendering for Multiple Volume Datasets Using Particle Fusion

  Kuwano Hiroshi, Sakamoto Naohisa, Koyamada Koji, Saito Ayumu, Kimura Akinori, Tanaka Satoshi

  We present a novel technique for rendering multiple volume datasets using particles as rendering primitives. In previous techniques, a data-intermixing process was required since the function is multi-valued. Although weighting values should be determined in this process, there are no specific guidelines for doing so. In contrast, our technique does not require data intermixing since we represent a volume dataset as a set of tiny, opaque particles which are generated with a stochastic technique. We applied our technique to volume datasets used for radiotherapy treatment planning in order to confirm its effectiveness.

  The Visualization Society of Japan, 2007, Journal of the Visualization Society of Japan, 27(1) (1), 43 - 44, Japanese


• J. Nonaka, N. Sakamoto, T. Kawamura, K. KoyamadaParticle-Based Volume Rendering of Unstructured Volume Data

  J. Nonaka, N. Sakamoto, T. Kawamura, K. KoyamadaParticle

  2007, 小山田耕二（教授） 【学会発表】 （査読付国際会議） Asia-Pacific Symposium on Visualization (APVIS 2007), Poster, 2007., English

  [Refereed]


• A real-time sensor network visualization system using KVS - Kyoto Visualization System

  Norihisa Segawa, Yukio Yasuhara, Naohisa Sakamoto, Tomoki Yoshihisa, Yasuo Ebara, Koji Koyamada

  2007, SENSYS'07: PROCEEDINGS OF THE 5TH ACM CONFERENCE ON EMBEDDED NETWORKED SENSOR SYSTEMS, 367 - 368, English

  [Refereed]


• Particle-based volume rendering

  Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada, Satoshi Tanaka

  2007, ASIA-PACIFIC SYMPOSIUM ON VISUALISATION 2007, PROCEEDINGS, 27(2) (2), 129 - +, English

  [Refereed]


• ポイントベースボリュームレンダリング法を用いた遠隔可視化環境の実装と評価

  櫻井健一, 坂本尚久, 江原康生, 曽根秀昭, 小山田耕二

  電気関係学会東北支部連合大会実行委員会, 2007, 電気関係学会東北支部連合大会講演論文集, 2007(0) (0), 121 - 121, Japanese


• シーングラフと可視化パイプラインを同一グラフ上で編集できる可視化システム

  Naohisa Sakamoto

  07 Sep. 2006, 日本バーチャルリアリティ学会大会論文集(CD-ROM), 11th, 3B2-2, Japanese


• Kriging for Volume Data Compression

  NONAKA Jorji, WATASHIBA Yasuhiro, YASUHARA Yukio, SAKAMOTO Naohisa, KOYAMADA Koji

  Volume data has been increasingly used in a wide range of applications in science and engineering. Advance in computer as well as in digital measuring technology have greatly increased the size and complexity of volume data. This sharp growth in data size is overwhelming the limit of the storing and processing capacity of traditional computer systems, and therefore an efficient data compression method is required. Considering this necessity, we have focused on a lossy compression method based on Kriging interpolation and extrema points. The compressed data will be composed of the extrema points, used as key points for data restoring, and three parameter values obtained from the entire data. Therefore, a great reduction in data size can be achieved. However, the parameter values and the starting points should be carefully selected in order to obtain good results. In this report, we present some results obtained from the KVS-based kriging compressor and discuss the potentials and problems of this proposed method.

  The Visualization Society of Japan, 01 Jul. 2006, 可視化情報学会誌. Suppl., 26(1) (1), 21 - 22, Japanese


• 統合可視化基盤KVS-概要と適用事例-

  坂本尚久

  2006, 京都大学学術情報メディアセンター広報 全国共同利用版, 5(2) (2), 32 - 41


• DTI-Mapper: A Framework for the Creation and Analysis of New Discriminants to Detect DTI Properties

  K. Sakai, K. Yamada, N. Sakamoto, J. Nonaka, K. Koyamada, Y. Yasuhara, S. Takagi, H. Oouchi, T. Nishimura

  2006, IEEE Visualization Proceedings Compendium, pp.32-33, English

  [Refereed]


• 応答曲面法を用いた生体機能シミュレーション向けパラメータ 最適化技術―初期評価実験での検証―

  山下由起子, 酒井晃二, 坂本尚久, 小山田耕二

  2006, 第1 回複合医工学シンポジウム(SCME2006) 予稿集pp.170-171, Japanese

  [Refereed]


• Kriging for Volume Data Compression

  NONAKA Jorji, WATASHIBA Yasuhiro, YASUHARA Yukio, SAKAMOTO Naohisa, KOYAMADA Koji

  Volume data has been increasingly used in a wide range of applications in science and engineering. Advance in computer as well as in digital measuring technology have greatly increased the size and complexity of volume data. This sharp growth in data size is overwhelming the limit of the storing and processing capacity of traditional computer systems, and therefore an efficient data compression method is required. Considering this necessity, we have focused on a lossy compression method based on Kriging interpolation and extrema points. The compressed data will be composed of the extrema points, used as key points for data restoring, and three parameter values obtained from the entire data. Therefore, a great reduction in data size can be achieved. However, the parameter values and the starting points should be carefully selected in order to obtain good results. In this report, we present some results obtained from the KVS-based kriging compressor and discuss the potentials and problems of this proposed method.

  The Visualization Society of Japan, 2006, Journal of the Visualization Society of Japan, 26(1) (1), 21 - 22, Japanese


• Improved hierarchical parameter optimization technique - Application for a cardiac myocyte model

  Yukiko Yamashita, Koji Sakai, Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada

  2006, 2006 28TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY, VOLS 1-15, 1, 3528 - +, English, International magazine

  [Refereed]


• “Study on Real-world oriented Visualization Environment for Remote Collaborative Works"

  Yasuo Ebara, Tetsuya Nabuchi, Naohisa Sakamoto, Koji Koyamada

  2006, IEEE International Conference on Computing & Informatics (ICOCI 2006), English

  [Refereed]


• “Volume Rendering with a Grid-Independent Illuminant Particle Model"

  Fredrika Rambu Ngana, Takuya Hatta, Naohisa Sakamoto, Jorji Nonaka, Satoshi Tanaka, Koji Koyamada

  2006, IEEE Visualization Proceedings Compendium, pp.28-29, English

  [Refereed]


• “Hierarchical Response Surface Methodology for Parameter Optimization: Efficiency of a Hierarchical RSM with a Hessian Matri χ", Systems Modeling and Simulation, Theory and Applications

  Teppei Tanaka, Koji Sakai, Yukiko Yamashita, Naohisa Sakamoto, Koji Koyamada

  2006, Asia Simulation Conference (ASC) 2006, Springer, ISBN 4-431-49021-3, pp.213-217, Tokyo, Japan, English

  [Refereed]


• Support system for estimation of earthquake fault plane within IPT

  Y. Yasuhara, N. Sakamoto, Y. Ebara, H. Katao, K. Koyamada

  2006, Proceedings of the 6th IASTED International Conference on Visualization, Imaging, and Image Processing, VIIP 2006, 453 - 458, English

  [Refereed]


• Volume rendering using tiny particles

  Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada, Satoshi Tanaka

  2006, ISM 2006: EIGHTH IEEE INTERNATIONAL SYMPOSIUM ON MULTIMEDIA, PROCEEDINGS, 734 - 737, English

  [Refereed]


• Improved hierarchical parameter optimization technique - Application for a cardiac myocyte model

  Yukiko Yamashita, Koji Sakai, Naohisa Sakamoto, Jorji Nonaka, Koji Koyamada

  2006, Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings, 2006, 3487 - 3490, English, International magazine

  [Refereed]


• Framework for creating new discriminats for detecting DTI properties: DTI mapper

  Koji Sakai, Naohisa Sakamoto, Jorji Nonaka, Yukio Yasuhara, Koji Koyamada

  IEEE, 2006, Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings, 4835 - 4839, English

  [Refereed]


• Study on eye-to-eye contact by multi-viewpoint videos merging system for tele-immersive environment

  Yasuo Ebara, Tetsuya Nabuchi, Naohisa Sakamoto, Koji Koyamada

  2006, 20TH INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS, VOL 2, PROCEEDINGS, 647 - +, English

  [Refereed]


• Density Mapping for Point-based Volume Rendering

  Sakamoto Naohisa, Koyamada Koji

  In this paper, we propose a technique for generating particles from user-specified transfer function for an effective point-based volume rendering. In general, a volume rendering technique utilizes an illumination model in which the 3D scalar field is characterized as a varying density emitter with a single level of scattering. In our method, the 3D scalar field is represented as a set of particles. The particle density is derived from a user-specified transfer function, and describes the probability that a particle is present at the point. Since the particles can be considered as fully opaque, no alpha blending but only depth comparison is required during the rendering calculation, which is advantageous is the distributed processing.

  Information Processing Society of Japan (IPSJ), 18 Aug. 2005, IPSJ SIG Notes, 2005(85) (85), 73 - 78, Japanese


• Density Mapping for Point-based Volume Rendering

  SAKAMOTO NAOHISA, KOYAMADA KOJI

  18 Aug. 2005, 情報処理学会研究報告, 2005(85(CG-120)) (85(CG-120)), 73 - 78, Japanese


• A Real-Time Transfer System of Human Movement for an Omni-Directional Display

  SAKAMOTO Naohisa, YASUHARA Yukio, KUKIMOTO Nobuyuki, EBARA Yasuo, KOYAMADA Koji

  本論文では, 多視点カメラ映像を用いて撮影された動きのある人物像を実時間で三次元データに変換し, ネットワーク転送によって遠隔地の全方位型表示装置に立体表示が可能なシステムを提案する. 本システムでは, 複数の映像から視体積交差法を利用することにより対象となる人物像をボクセルとして復元する. 復元されたボクセルは, 物体の有無だけを表現しており, 引き続き, ボクセルを各映像面に射影することにより得られるテクスチャ情報を用いたカラーリング処理が必要となる. このカラーリング処理では, ボクセルの可視判定処理が重要となる. 本研究では, 映像撮影から表示までを実時間処理するために, カメラ単位での人物バッファを用いた並列カラーリング処理手法を開発し, ボクセルの実時間可視判定を実現した. 本システムの有効性を検証するためにカメラ5台とPC6台からなる多視点カメラ映像処理実験システムを試作し, 動きのある人物像を用いて, 復元の空間解像度が96×

  The Institute of Electronics, Information and Communication Engineers, 01 Aug. 2005, The transactions of the Institute of Electronics, Information and Communication Engineers. D-II, 88(8) (8), 1539 - 1548, Japanese


• Development and Evaluation of PDA-based Control Interface for Omni-directional display

  YASUHARA Yukio, SAKAMOTO Naohisa, KUKIMOTO Nobuyuki, EBARA Yasuo, KOYAMADA Koji

  映像情報メディア学会, 03 Jun. 2005, ITE technical report, 29(31) (31), 35 - 40, Japanese


• Development and Evaluation of PDA-based Control Interface for Omni-directional display

  YASUHARA Yukio, SAKAMOTO Naohisa, KUKIMOTO Nobuyuki, EBARA Yasuo, KOYAMADA Koji

  ヒュ-マンインタフェ-ス学会, 03 Jun. 2005, Human Interface, 7(3) (3), 35 - 40, Japanese


• Development and Evaluation of PDA-based Control Interface for Omni-directional display

  Yasuhara Yukio, Sakamoto Naohisa, Kukimoto Nobuyuki, Ebara Yasuo, Koyamada Koji

  The omni-directional display system is an effective 3D displaying method in the environment of group observation. In this research, we developed a control user interface for the omni-directional display system. In general, a keyboard and a mouse are considered as the user interface for control on the display of computer easily. However, it is necessary that some users can operate the display freely at each position around the omni-directional display system. In addition, it is considered that inexperienced users can control easily by showing the various functions visually. Therefore, we implemented the user interface by using PDA (Personal Digital Assistants). By using the developed control user interface, we enabled to use some functions. viz. the control as rotation or translation, the pointing to the displaying object, and the annotations. In this paper, we introduce the implementation of developed PDA-based control interface, and we discuss the evaluation experiment concerning the usability of proposed interface.

  The Institute of Electronics, Information and Communication Engineers, 27 May 2005, Technical report of IEICE. Multimedia and virtual environment, 105(106) (106), 35 - 40, Japanese


• 3D Visualization of the Bedrock Destroying phenomenon on Tele-Immersive Virtual Environment

  KUKIMOTO Nobuyuki, YASUHARA Yukio, SAKAMOTO Naohisa, NONAKA Jorji, EBARA Yasuo, KOYAMADA Koji

  It is highly important to comprehend the destruction phenomenon of bedrock structures because earthquakes usually occur by destroying the rocks inside the earth. This destruction sometimes oc-curs concurrently at different places because of aftershocks. For instance, the Mid-Niigata Prefecture Earthquake occurred in 2004 has generated several aftershocks, as a result it was considered an uncommon and complex earthquake. Traditional earthquake analysis has used the three orthographic views, however the use of 3D visualization for showing the destruction phenomenon can be considered as of highly importance. Taking this into consideration, we describe in this paper an attempt to visualize the destruction phenomenon of the Mid-Niigata prefecture Earthquake by using an Immersive Projection based Technology (IPT).

  The Visualization Society of Japan, 15 Mar. 2005, 可視化情報学会誌. Suppl., 25(1) (1), 121 - 122, Japanese


• Acceleration of 3D Reconstruction by Using Color Information

  坂本 尚久, 小山田耕二

  複数枚のカメラ画像から物体の３次元形状を復元する場合，物体の外形を表すシルエット画像をもとにして処理を行う視体積交差法が多く利用されている．一般に，この手法により求められる形状データは，テクスチャ情報を持たないため，テクスチャに関する処理が別途必要となる．本報告では，シルエット画像だけでなく，撮影画像から得られる色情報も考慮することにより，物体形状の復元処理とテクスチャ処理を区別なく行うことで，一連の３次元形状復元処理を高速化する手法を提案する．In this paper, we describe an acceleration technique for 3D reconstruction which uses color information acquired from captured images. Volume intersection method is one of the most efficient methods for reconstructing objects in real scenes from silhouette images. Generally, the reconstructed object by using this method has no texture information. Therefore, an additional texturing stage is required after the reconstruction process. To overcome this problem, we propose an acceleration technique for this 3D reconstructio

  07 Feb. 2005, 情報処理学会研究報告グラフィクスとCAD（CG）, 2005(13) (13), 25 - 30, Japanese


• Acceleration of 3D Reconstruction by Using Color Information

  Sakamoto Naohisa, Koyamada Koji

  In this paper we describe an acceleration technique for 3D reconstruction which uses color information acquired from captured images. Volume intersection method is one of the most efficient methods for reconstructing objects in real scenes from silhouette images. Generally, the reconstructed object by using this method has no texture information. Therefore, an additional texturing stage is required after the reconstruction process. To overcome this problem, we propose an acceleration technique for this 3D reconstruction process which takes into account not only the silhouettes but also color information from captured images.

  Information Processing Society of Japan (IPSJ), 07 Feb. 2005, IPSJ SIG Notes, 2005(13) (13), 25 - 30, Japanese


• Acceleration of 3D Reconstruction by Using Color Information

  SAKAMOTO Naohisa, KOYAMADA Koji

  東京 : 情報処理学会, 07 Feb. 2005, 情報処理学会研究報告. CG,グラフィクスとCAD研究会報告, 118(13) (13), 25 - 30, Japanese


• 3D Object Reconstruction by using Toy Blocks in Real World

  Koji Sakai, Naohisa Sakamoto, Koji Koyamada, Tatsuo Hasegawa

  2005, NICOGRAPH International 2005, pp.107-110, English

  [Refereed]


• An Experiment on Eye-to-Eye Contact using Auto-stereoscopic Display for Tele-immersive System

  Tetsuya Nabuchi, Yasuo Ebara, Naohisa Sakamoto, Koji Koyamada

  2005, M2USIC2005, pp.13-16, English

  [Refereed]


• PDAを用いた全方位型表示システム向け操作インタフェース

  安原幸生, 久木元伸如, 坂本尚久, 江原康生, 小山田耕二

  2005, インタラクション2005 シンポジウム, C-302, Japanese

  [Refereed]


• Particle generation from user-specified transfer function for point-based volume rendering

  Naohisa Sakamoto, Koji Koyamada

  IEEE Computer Society, 2005, Proceedings of the IEEE Visualization Conference, 108 - 108, English

  [Refereed]


• 3D data transmitting and displaying system with an omni-directional display for group learning

  Yukio Yasuhara, Nobuyuki Kukimoto, Naohisa Sakamoto, Yasuo Ebara, Koji Koyamada

  IEEE Computer Society, 2005, Proceedings - Third International Conference on Creating, Connecting and Collaborating through Computing, C5 2005, 2005, 43 - 49, English

  [Refereed]


• Virtual object reconstruction in real world

  K Sakai, N Sakamoto, K Koyamada, T Hasegawa

  2005, 11TH INTERNATIONAL CONFERENCE ON PARALLEL AND DISTRIBUTED SYSTEMS WORKSHOPS, VOL II, PROCEEDINGS,, 214 - 218, English

  [Refereed]


• Interactive controller for 3D contents with omni-directional display

  Yukio Yasuhara, Naohisa Sakamoto, Nobuyuki Kukimoto, Yasuo Ebara, Koji Koyamada

  IEEE Computer Society, 2005, Proceedings of the International Conference on Parallel and Distributed Systems - ICPADS, 2, 167 - 171, English

  [Refereed]


• Multi-view image integration system for glass-less 3-D display

  T Ando, K Mashitani, M Higashino, H Kanayama, H Murata, Y Funazou, N Sakamoto, H Hazama, Y Ebara, K Koyamada

  2005, Stereoscopic Displays and Virtual Reality Systems XII, 5664, 158 - 166, English

  [Refereed]


• 3D Visualization of the Bedrock Destroying phenomenon on Tele-Immersive Virtual Environment

  KUKIMOTO Nobuyuki, YASUHARA Yukio, SAKAMOTO Naohisa, NONAKA Jorji, EBARA Yasuo, KOYAMADA Koji

  It is highly important to comprehend the destruction phenomenon of bedrock structures because earthquakes usually occur by destroying the rocks inside the earth. This destruction sometimes oc-curs concurrently at different places because of aftershocks. For instance, the Mid-Niigata Prefecture Earthquake occurred in 2004 has generated several aftershocks, as a result it was considered an uncommon and complex earthquake. Traditional earthquake analysis has used the three orthographic views, however the use of 3D visualization for showing the destruction phenomenon can be considered as of highly importance. Taking this into consideration, we describe in this paper an attempt to visualize the destruction phenomenon of the Mid-Niigata prefecture Earthquake by using an Immersive Projection based Technology (IPT).

  The Visualization Society of Japan, 2005, Journal of the Visualization Society of Japan, 25(1) (1), 121 - 122, Japanese


• DT‐MRIデータを用いた脳白質神経線維の可視化

  酒井晃二, 小山田耕二, 坂本尚久

  15 Sep. 2004, 日本磁気共鳴医学会雑誌, 24(Supplement(Sept)) (Supplement(Sept)), 261, Japanese


• Graphical User Interface for Face-to-Face Collaboration with a 3D Image

  KUKIMOTO NOBUYUKI, FUKUZAWA HIDENORI, SHOZU MAKOTO, EBARA YASUO, SAKAMOTO NAOHISA, NONAKA J, WATASHIBA YASUHIRO, KOYAMADA KOJI

  08 Sep. 2004, 日本バーチャルリアリティ学会大会論文集(CD-ROM), 9th, 1A1-5, Japanese


• An Omni-directional Display Technique of 3D Real Scenes

  YASUHARA YUKIO, SAKAMOTO NAOHISA, KUKIMOTO NOBUYUKI, EBARA YASUO, KOYAMADA KOJI

  08 Sep. 2004, 日本バーチャルリアリティ学会大会論文集(CD-ROM), 9th, 1D2-5, Japanese


• Multi-view image integration system for glass-less 3-D display

  ANDO TAKAHISA, MASHITANI KEN, HIGASHINO MASAHIRO, KANAYAMA HIDEYUKI, MURATA HARUHIKO, SAKAMOTO NAOHISA, HAZAMA HIROSHI, EBARA YASUO, KOYAMADA KOJI

  08 Sep. 2004, 日本バーチャルリアリティ学会大会論文集(CD-ROM), 9th, 2B3-1, Japanese


• A Visualization of the Neural Pathway from DT-MRI data set

  SAKAI Koji, SAKAMOTO Naohisa, KOYAMADA Koji, DOI Akio

  Diffusion tensor magnetic resonance imaging (DT-MRI) is a technique used to measure the anistropic diffusion properties of the water molecules in the organism. And this technique has been utilized for the diagnosis of the diseases of brain as like a cerebral infarction, a brain tumor, and variable cases. On the other hand, the dissection is the only way to obtain the visible information of the neural pathway in the brain white matter with the exception of DT-MRI. The visualization technique called "tractography" allows the user to visualize the neural pathway from DT-MRI data that needs to set of the starting point and the end point of a pathway. These points have been set by user's medical intention and there has been no the other guideline. So, we calculated isotropic region in tensor field by using the DT-MRI data set, and proposed the technique which made the visible seed area information of neural pathways. In this paper, the method of the isotropic area computation from the DT-MRI data set and the flow of neural pathway of specified region ware shown with the suitable example.

  The Visualization Society of Japan, 01 Jul. 2004, Kashika Joho, 24(1) (1), 451 - 452, Japanese


• 3D Modeling and Displaying System for Volume Communication

  SAKAMOTO Naohisa, KUKIMOTO Nobuyuki, YASUHARA Yukio, EBARA Yasuo, KOYAMADA Koji

  2004, Int Symp Adv Fluid Inf, 4th, 159 - 164, English

  [Refereed]


• 協調作業環境のためのインタラクティブ 操作可能な全方位型3 次元表示システム

  坂本尚久, 久木元伸如, 安原幸生, 江原康生, 小山田耕二

  2004, 第20 回NICOGRAPH 論文コンテスト論文集, pp.95-99, 2004., Japanese

  [Refereed]


• A Visualization of the Neural Pathway from DT-MRI data set

  SAKAI Koji, SAKAMOTO Naohisa, KOYAMADA Koji, DOI Akio

  Diffusion tensor magnetic resonance imaging (DT-MRI) is a technique used to measure the anistropic diffusion properties of the water molecules in the organism. And this technique has been utilized for the diagnosis of the diseases of brain as like a cerebral infarction, a brain tumor, and variable cases. On the other hand, the dissection is the only way to obtain the visible information of the neural pathway in the brain white matter with the exception of DT-MRI. The visualization technique called "tractography" allows the user to visualize the neural pathway from DT-MRI data that needs to set of the starting point and the end point of a pathway. These points have been set by user's medical intention and there has been no the other guideline. So, we calculated isotropic region in tensor field by using the DT-MRI data set, and proposed the technique which made the visible seed area information of neural pathways. In this paper, the method of the isotropic area computation from the DT-MRI data set and the flow of neural pathway of specified region ware shown with the suitable example.

  The Visualization Society of Japan, 2004, Journal of the Visualization Society of Japan, 24(1) (1), 451 - 452, Japanese


• Multi-viewpoint videos merging system using auto-stereoscopic display in tele-immersion

  H Hazama, N Sakamoto, H Horii, Y Ebara, K Koyamada

  2004, PROCEEDINGS OF THE FOURTH IASTED INTERNATIONAL CONFERENCE ON VISUALIZATION, IMAGING, AND IMAGE PROCESSING, 719 - 724, English

  [Refereed]


• A parallel approach for volumetric reconstruction

  N Sakamoto, JJ Nonaka, K Koyamada

  2004, PROCEEDINGS OF THE FOURTH IASTED INTERNATIONAL CONFERENCE ON VISUALIZATION, IMAGING, AND IMAGE PROCESSING, 843 - 848, English

  [Refereed]


• Voxelization of hexahedral cell with the two-pass rasterization technique

  N Sakamoto, K Koyamada, K Sakai, M Kikugawa

  2004, PROCEEDINGS OF THE FOURTH IASTED INTERNATIONAL CONFERENCE ON VISUALIZATION, IMAGING, AND IMAGE PROCESSING, 178 - 181, English

  [Refereed]


• An analytical method for the weather phenomena with critical point visualization

  K Sakai, N Sakamoto, K Koyamada

  2004, PROCEEDINGS OF THE FOURTH IASTED INTERNATIONAL CONFERENCE ON VISUALIZATION, IMAGING, AND IMAGE PROCESSING, 172 - 177, English

  [Refereed]


• New Data Reduction Approarch by Image-Based Modeling Technique with CG Camera.

  Miyachi Hideo, Sakamoto Naohisa

  We have proposed a new data reduction approach to apply the image based modeling and rendering trechnique to computer graphics models. It allows us to reduce the color and the geometric information independently, so it is effective for visualized models with the color as key information. As a result of subjective recognition test, a part of people answered the recovered model by our method has higher quality than the simplified model by using only geometry simplification method.

  The Japan Joint Automatic Control Conference, 2004, Proceedings of the Japan Joint Automatic Control Conference, 47(0) (0), 39 - 39, Japanese


• 特異点可視化による気圧場の知見探索 : オホーツク海高気圧と低気圧発達への適用

  酒井 晃二, 高井 博司, 坂本 尚久, 小山田 耕二, 土井 章男

  日本気象学会, 15 Oct. 2003, 大会講演予講集, 84, 376 - 376, Japanese


• A Streaming-based Technique for Volume Rendering of Large Datasets

  WATASHIBA Yasuhiro, KOYAMADA Kohji, KANAZAWA Masanori, NONAKA Jorji, SAKAMOTO Naohisa

  We present a streaming-based technique of volume rendering which breaks a large volume data into pieces (sub-volumes) so as to maintain volume rendering processing in physical memory in consideration of the available system resources. Each sub-volume is transferred to a rendering PC, which performs hardware accelerated volume rendering and generates a partial image (sub-image). The sub-images are piled up in depth order to complete the final image. In the rendering PC, we have used general-purpose consumer PC graphics cards (Geforce4) to our system as a low cost solution for large-scale volume rendering. Furthermore, in order to improve the rendering quality, we use not a plane slice sampling but an iso-distance surface slice sampling. This technique has been applied to remote visualization of 3-D finite element analysis result of 3-D flow through a lateral saccular aneurysm, and its effectiveness is confirmed.

  可視化情報学会, 01 Jul. 2003, Journal of the Visualization Society of Japan, 23(1) (1), 387 - 390, Japanese


• Development of 3D Video Display System Using Omnidirectional Display

  SAKAMOTO Naohisa, TAKAI Takeshi, KOYAMADA Koji, MATSUYAMA Takashi, KIKKAWA Yoshihito

  In this paper, we describe the development, of a 3D video imaging system for an omnidirectional display in which many people can visualize the same image from different viewpoints at the same time. In order to display such images, in a high quality manner, it is necessary to reduce the discontinuity between adjacent patches during the texture mapping process of reconstructed geometrical shape. To overcome this problem, a view-dependent texture mapping has been used. Such method is only effective for a traditional 2D display. To overcome this limitation, we have developed a view-independent, voxel coloring for an omnidirectional display by using multi-viewpoint video images. In this technique, accurate visibility determination is done in order to diminish the influence of specular reflection, which is the main obstacle for viewpoint independence. We used 12 sets of 300 time-varying frames, each set corresponding to a specific viewpoint, to verify the effectiveness of our approach.

  可視化情報学会, 01 Jul. 2003, Journal of the Visualization Society of Japan, 23(1) (1), 399 - 402, Japanese


• 特異点可視化による気象現象の解析手法

  酒井晃二, 坂本尚久, 小山田耕二, 土井章男

  2003, 可視化情報学会 第９回ビジュアリゼーションカンファレンス講演予稿集CD, Japanese

  [Refereed]


• A Technique or Specifying Region of Interest (ROI) in the Vector Field Based on 3D LIC.

  SAKAI Koji, KOYAMADA Koji, SAKAMOTO Naohisa, MATSUDA Koichi, DOI Akio

  Line integral convolution (LIC) is an effective and powerful technique for generating images from vector fields. In the 3D-LIC, it is very important to select an adequate region of interest (ROI) in the vector field. A way for specifying ROI is to use a surface defined in the vector field. Another way is to use a significance setting that defines a ROI related values at each point in the vector field. To represent an anisotropic vector field around a vortex center in an understandable way, we introduced a time-oriented significance setting. Our technique for specifying ROI is to use a passage-time for a mass-less particle to travel from near a vortex center to a pixel location.  In our technique, what we call "restricted LIC technique", we refer to the passage-time buffer before we start the convolution process at a pixel location. The original RLIC technique is based on 2 -D. In this paper, we extend this technique to 3 -D. To confirm the effectiveness of our technique, we use an anisotropic swirl vector field and construct two types of significance settings, which are a distance-oriented and a time-oriented setting. We will show the difference in the resulting images between a

  The Institute of Image Electronics Engineers of Japan, 2003, The Journal of the Institute of Image Electronics Engineers of Japan, 32(6) (6), 815 - 824, Japanese


• Development of 3D Video Display System Using Omnidirectional Display

  SAKAMOTO Naohisa, TAKAI Takeshi, KOYAMADA Koji, MATSUYAMA Takashi, KIKKAWA Yoshihito

  In this paper, we describe the development, of a 3D video imaging system for an omnidirectional display in which many people can visualize the same image from different viewpoints at the same time. In order to display such images, in a high quality manner, it is necessary to reduce the discontinuity between adjacent patches during the texture mapping process of reconstructed geometrical shape. To overcome this problem, a view-dependent texture mapping has been used. Such method is only effective for a traditional 2D display. To overcome this limitation, we have developed a view-independent, voxel coloring for an omnidirectional display by using multi-viewpoint video images. In this technique, accurate visibility determination is done in order to diminish the influence of specular reflection, which is the main obstacle for viewpoint independence. We used 12 sets of 300 time-varying frames, each set corresponding to a specific viewpoint, to verify the effectiveness of our approach.

  The Visualization Society of Japan, 2003, Journal of the Visualization Society of Japan, 23(1) (1), 399 - 402, Japanese


• A Streaming-based Technique for Volume Rendering of Large Datasets

  WATASHIBA Yasuhiro, KOYAMADA Kohji, KANAZAWA Masanori, NONAKA Jorji, SAKAMOTO Naohisa

  We present a streaming-based technique of volume rendering which breaks a large volume data into pieces (sub-volumes) so as to maintain volume rendering processing in physical memory in consideration of the available system resources. Each sub-volume is transferred to a rendering PC, which performs hardware accelerated volume rendering and generates a partial image (sub-image). The sub-images are piled up in depth order to complete the final image. In the rendering PC, we have used general-purpose consumer PC graphics cards (Geforce4) to our system as a low cost solution for large-scale volume rendering. Furthermore, in order to improve the rendering quality, we use not a plane slice sampling but an iso-distance surface slice sampling. This technique has been applied to remote visualization of 3-D finite element analysis result of 3-D flow through a lateral saccular aneurysm, and its effectiveness is confirmed.

  The Visualization Society of Japan, 2003, Journal of the Visualization Society of Japan, 23(1) (1), 387 - 390, Japanese


• A Technique for Specifying Region of Interest (ROI) in the Vector Field Based on 3D LIC

  SAKAI Koji, KOYAMADA Koji, SAKAMOTO Naohisa, MATSUDA Koichi, DOI Akio

  Line integral convolution (LIC) is an effective and powerful technique for generating images from vector fields. In the 3D-LIC, it is very important to select an adequate region of interest (ROI) in the vector field. A way for specifying ROI is to use a surface defined in the vector field. Another way is to use a significance setting that defines a ROI related values at each point in the vector field. To represent an anisotropic vector field around a vortex center in an understandable way, we introduced a time-oriented significance setting. Our technique for specifying ROI is to use a passage-time for a mass-less particle to travel from near a vortex center to a pixel location.
    In our technique, what we call “restricted LIC technique”, we refer to the passage-time buffer before we start the convolution process at a pixel location. The original RLIC technique is based on 2 -D. In this paper, we extend this technique to 3 -D. To confirm the effectiveness of our technique, we use an anisotropic swirl vector field and construct two types of significance settings, which are a distance-oriented and a time-oriented setting. We will show the difference in the resulting images between a distance-oriented and time-oriented significance settings.
  

  The Institute of Image Electronics Engineers of Japan, 2003, The Journal of the Institute of Image Electronics Engineers of Japan, 32(6) (6), 815 - 824, Japanese


• Voxelモデルによる3次元形状の多重解像度表現

  阪井謙一, 岩成英一, 坂本尚久, 岡田至弘

  07 Mar. 2001, 電子情報通信学会大会講演論文集, 2001, 273, Japanese


• Multiresolution Representaion of 3D Shape Based on Voxel Model

  Sakai Kenichi, Iwanari Eiici, Sakamoto Naohisa, Okada Yoshihiro

  The Institute of Electronics, Information and Communication Engineers, 07 Mar. 2001, Proceedings of the IEICE General Conference, 2001(2) (2), 273 - 273, Japanese


• Reconstruction of 3D Objects by Octree Representation from Multiple Any Views

  SAWA Hiroyoshi, SAKAMOTO Naohisa, IWANARI Eiichi, OKADA Yoshihiro, KANADE Takeo

  In this research, we purpose a system to reconstruct the 3D objects based on the images from any views. First, we calibrate the camera by using a perspective projection matrix which combines the corresponding points in the 3D space and in the 2D image. And then, we are able to take pictures from any views in any focal length, and obtain images with high mobility and fewer occlusion. Next we extract object silhouette by the threshold method using color information. Finally, we reconstruct the 3D skeleton object by octree representation based on silhouette information and calibration data of the input images from multiple any views.

  Information Processing Society of Japan (IPSJ), 18 Mar. 1999, CVIM, 115(29(CVIM-115)) (29(CVIM-115)), 33 - 40, Japanese


• 任意視点からの3次元復元のためのカメラキャリブレーション

  坂本尚久, 沢弘義, 岡田至弘

  08 Mar. 1999, 電子情報通信学会大会講演論文集, 1999, 344, Japanese


• Camera Calibration for Rconstruction of 3D Object from Any Viewpoints

  Sakamoto Naohisa, Sawa Hiroyoshi, Okada Yoshihiro

  The Institute of Electronics, Information and Communication Engineers, 1999, Proceedings of the IEICE General Conference, 171(2) (2), 344 - 344, Japanese


• 拡散テンソルMRI 用識別子 作成フレームワーク:DTI-Mapper

  酒井晃二, 山田惠, 坂本尚久, ジョルジノナカ, 安原幸生, 小山田耕二, 西村恒彦

  日本磁気共鳴医学会雑誌Vol.2X 、第34 回磁気共鳴医学会大会講演抄録集, p.193, Japanese

  [Refereed]

• "ボリュームデータ（分野：可視化、部門：ボリューム可視化）", シミュレーション辞典 (日本シミュレーション学会編)

  Naohisa Sakamoto

  Others, コロナ社, Feb. 2012, Japanese

  Dictionary or encycropedia


• Excelで学ぶ コンピュータグラフィックス技術入門

  坂本 尚久, 小山田 耕二

  Joint work, コロナ社, Jun. 2011, Japanese, ISBN: 4339024554

  Scholarly book

  


• Excelで学ぶコンピュータグラフィックス技術入門

  坂本, 尚久, 小山田, 耕二

  コロナ社, 2011, Japanese, ISBN: 9784339024555


• 粒子ボリュームレンダリング - 理論とプログラミング -

  小山田 耕二, 坂本 尚久

  Joint work, コロナ社, Oct. 2010, Japanese, ISBN: 433902449X

  Scholarly book

  


• 粒子ボリュームレンダリング : 理論とプログラミング

  小山田, 耕二, 坂本, 尚久

  コロナ社, Oct. 2010, Japanese, ISBN: 9784339024494


• Particle based Volume Rendering - Theory and Programming -

  Naohisa Sakamoto, Koji Koyamada

  Joint work, コロナ社, Oct. 2010, Japanese

  Scholarly book


• 粒子ボリュームレンダリング

  小山田耕二, 坂本尚久

  Joint work, コロナ社， 2010., 2010, Japanese

  Scholarly book


• 可視化プログラミングの基礎（2）粒子ベースボリュームレンダリング

  坂本尚久, 小山田耕二

  Joint work, 日本計算工学会, Jan. 2009, Japanese

  Scholarly book


• 可視化プログラミングの基礎（3）GPU を利用した粒子ベースボリュームレンダリング の高速化

  坂本尚久, 小山田耕二

  Joint work, （解説）計算工学会，Vol. 14、No. 2、pp. 2062-2069, 2009, Japanese

  Scholarly book

• 粒子ベースレンダリングの高速化のための多重カーネルノイズ除去オートエンコーダ

  森井 雅大, 坂本 尚久, 河村 拓馬

  第51回可視化情報シンポジウム（可視化情報学会主催）, Aug. 2023, Japanese

  Oral presentation


• 情報エントロピーを用いたin-situ可視化向けカメラ注視点推定

  松島 大晟, 坂本 尚久, 野中 丈士, 畢 重科

  第51回可視化情報シンポジウム（可視化情報学会主催）, Aug. 2023, Japanese


• 任意視点可視化画像生成のための画像ベースサロゲートモデルの構築

  田中 祐希, 坂本 尚久

  第51回可視化情報シンポジウム（可視化情報学会主催）, Aug. 2023, Japanese

  Oral presentation


• 類似度に基づくアンサンブルデータ向け視覚的データ探索

  小林 世奈, 坂本 尚久, 渡辺 敬太, 野中 丈士, 前島 康光

  第51回可視化情報シンポジウム（可視化情報学会主催, Aug. 2023, Japanese

  Oral presentation


• 次元削減技術を用いた視覚的テンソルデータ解析

  藤田啓二郎, 坂本 尚久

  第6回ビジュアリゼーションワークショップ（可視化情報学会主催）, Mar. 2023, Japanese

  Poster presentation


• Log Data Visual Analytics System for Analyzing Cooling System Behavior of HPC System

  Fujita Keijiro, Naohisa Sakamoto, Takanori Fujiwara, Toshiyuki Tsukamoto, Jorji Nonaka

  The 5th R-CCS International Symposium, Feb. 2023, English

  Poster presentation


• ngular-based Edge Bundled Parallel Coordinates Plot for the Visual Analysis of Large Ensemble Simulation Data

  Keita Watanabe, Naohisa Sakamoto, Yasumitsu Maejima, Jorji Nonaka

  The 5th R-CCS International Symposium, Feb. 2023, English

  Poster presentation


• Camera Path Estimation for In-situ Visualization

  Ken Iwata, Naohisa Sakamoto, Jorji Nonaka, Chongke Bi

  The 5th R-CCS International Symposium, Feb. 2023, English

  Poster presentation


• テンソル分解を用いた多次元時系列データ向け視覚的比較分析

  岡見 直樹, 坂本 尚久, 藤原 孝紀, 野中 丈士, 塚本 俊之

  第51回可視化情報シンポジウム（可視化情報学会主催）, 2023, Japanese

  Oral presentation


• 気象アンサンブルデータ向け視覚的分析法

  坂本 尚久

  第96回CG・可視化研究会, Nov. 2022

  [Invited]

  Invited oral presentation


• Tensor-based Visual Analytics for Multidimensional Time-series Data

  Naohisa Sakamoto

  International Conference on Data Science, Statistics & Visualization (DSSV2022), Jun. 2022, English

  [Invited]

  Invited oral presentation


• Performance Improvement of Stochastic Rendering using Convolutional Neural Network based Denoising

  Amirul Haziq, bin Azman, Naohisa Sakamoto

  The 5th Visualization Workshop (sponsored by Visualization Society of Japan), Feb. 2022, Japanese

  Poster presentation


• エッジ束化平行座標プロットによるアンサンブルデータ向け視覚分析システム

  渡辺 敬太, 田村 剛, 坂本 尚久, 前島 康光, 野中 丈士

  第５回ビジュアリゼーションワークショップ（可視化情報学会主催）, Feb. 2022, Japanese

  Poster presentation


• 次元削減技術を用いた視覚的テンソルデータ解析手法

  藤田 啓二郎, 坂本 尚久, 藤原 孝紀, 塚本 俊之, 野中 丈士

  第５回ビジュアリゼーションワークショップ（可視化情報学会主催）, Feb. 2022, Japanese

  Poster presentation


• 情報エントロピーに基づくin-situ可視化向け最適視点移動経路推定法

  岩田 憲, 坂本 尚久, 野中 丈士

  第５回ビジュアリゼーションワークショップ（可視化情報学会主催）, Feb. 2022, Japanese

  Poster presentation


• アンサンブルシミュレーションデータ向け視覚的時空間特徴解析

  田村 剛, 坂本 尚久, 前島 康光, 野中 丈士

  第５回ビジュアリゼーションワークショップ（可視化情報学会主催）, Feb. 2022, Japanese

  Poster presentation


• Evaluation of CNN-based Denoising Methods for Particle-based Rendering

  Amirul Haziq, bin Azman, Naohisa Sakamoto

  先進的描画技術を用いた可視化情報の研究会（VR2021）, Dec. 2021, Japanese

  Oral presentation


• アンサンブルメンバー比較のためのエッジ束化平行座標プロット

  渡辺敬太, 田村剛, 坂本尚久, 野中丈士, 前島康光

  先進的描画技術を用いた可視化情報の研究会（VR2021）, Dec. 2021, Japanese

  Oral presentation


• 情報エントロピーに基づくIn-situ可視化向け最適視点推定法

  岩田憲, 坂本尚久, 野中丈士

  先進的描画技術を用いた可視化情報の研究会（VR2021）, Dec. 2021, Japanese


• 多次元時系列データの視覚的解析

  坂本 尚久

  総合工学委員会・科学的知見の創出に資する可視化分科会・ICT時代の文理融合研究を創出する可視化小委員会 (第25期・第3回), Dec. 2021


• 粒子ベースレンダリングによる数値シミュレーションデータ向け遠隔VR可視化システム

  河村 拓馬, 坂本 尚久

  可視化情報学会 第49回 可視化情報シンポジウム, Sep. 2021, Japanese

  Oral presentation


• 探索的in-situ可視化向け多視点レンダリング基盤の開発

  酒匂 太輝, 坂本 尚久, 野中 丈士

  可視化情報学会 第49回 可視化情報シンポジウム, Sep. 2021, Japanese

  Oral presentation


• 多段階次元削減を用いた時系列ログデータ向け視覚的分析手法

  藤田 啓二郎, 坂本 尚久, 野中 丈士, 藤原 孝紀

  可視化情報学会 第49回 可視化情報シンポジウム, Sep. 2021, Japanese

  Oral presentation


• 効率的な知見獲得を目指した大規模数値計算向けスマートIn-situ可視化

  坂本 尚久

  プラズマシミュレーションシンポジウム2021, Sep. 2021

  [Invited]

  Invited oral presentation


• Smart In-situ Visualization for Large-scale Numerical Simulations Aiming at Efficient Knowledge Acquisition

  Naohisa Sakamoto

  The 4th China-Japan Join Visualization Workshop, Jul. 2021, English

  [Invited]

  Invited oral presentation


• 探索的in-situ可視化向け多視点レンダリング基盤の開発

  酒匂太輝, 坂本尚久

  日本バーチャルリアリティ学会 第43回テレイマージョン技術研究会, Mar. 2021, Japanese

  Oral presentation


• 動的モード分解を用いた数値シミュレーションデータ向け視覚的モード探索

  宮崎 陽祐, 坂本 尚久

  日本バーチャルリアリティ学会 第43回テレイマージョン技術研究会, Mar. 2021, Japanese

  Oral presentation


• A Visual Causality Exploration System for HPC Hardware Failure Analysis

  Kazuki Koiso, Naohisa Sakamoto, Jorji Nonaka, Keiji Yamamoto, Fumiyoshi Shoji

  The 2nd R-CCS International Symposium, Feb. 2020, English

  Poster presentation


• Adaptive Spatial and Temporal Sampling for In-situ Visualization

  Yoshiaki Yamaoka, Naohisa Sakamoto, Jorji Nonaka

  The 2nd R-CCS International Symposium, Feb. 2020, English

  Poster presentation


• Visual Analysis of Meteorological Ensemble Data Sets by using Stochastic Isosurface Visualization

  Go Tamura, Naohisa Sakamoto, Yasumitsu Maejima, Jorji Nonaka

  The 2nd R-CCS International Symposium, Feb. 2020, English

  Poster presentation


• A Brief Analysis of the K Computer by using the HPC Facility's Water Cooling Subsystem

  Jorji Nonaka, Toshiyuki Tsukamoto, Motohiko Matsuda, Keiji Yamamoto, Akiyoshi Kuroda, Atsuya Uno, Shun Ito, Naohisa Sakamoto

  The 2nd R-CCS International Symposium, Feb. 2020, English

  Poster presentation


• 三次元平行座標可視化技術を使った多次元データ向け没入型視覚分析環境の構築

  田畑 銀河, 坂本 尚久

  先進的可視化環境を用いた可視化情報の研究会（VR2019), Jan. 2020, Japanese

  Oral presentation


• 確率的等値面可視化技術を使った気象アンサンブルデータ分析

  田村 剛, 坂本 尚久, 前島 康光, 野中 丈士

  先進的可視化環境を用いた可視化情報の研究会（VR2019), Jan. 2020, Japanese

  Oral presentation


• スパコンからVRシステムまでサポートする視覚的データ探索基盤の開発

  田畑 銀河, 坂本 尚久

  日本バーチャルリアリティ学会 第39回テレイマージョン技術研究会, Dec. 2019, Japanese

  Oral presentation


• スーパーコンピュータ向け科学的可視化

  坂本 尚久

  第10回横幹連合コンファレンス (OS18 令和の時代のシミュレーション技術：複雑系，スーパーコンピューティング，可視化), Dec. 2019, Japanese

  Oral presentation


• A View from the Facility Operations Side on the Long-Term Operation of the K Computer System

  Jorji Nonaka, Keiji Yamamoto, Akiyoshi Kuroda, Toshiyuki Tsukamoto, Kazuki Koiso, Naohisa Sakamoto

  The 2019 Conference on Supercomputing (SC19), Nov. 2019, English

  Poster presentation


• Transfer Entropy based Visual Causality Analysis of a Sever Rainfall Event

  Naohisa Sakamoto, Jorji Nonaka, Yasumitsu Maejima, Koji Koyamada

  VizAfrica 2019 Data Visualization Symposium, Nov. 2019, English

  Oral presentation


• In-situ可視化向け適応的時間サンプリング法

  山岡 義昭, 林 賢悟, 坂本 尚久, 野中 丈士, 吉永 司, 野崎 一徳

  日本流体力学会 第33回数値流体力学シンポジウム (CFD33), Nov. 2019, Japanese

  Oral presentation


• 大規模数値計算結果の時空間分布変化を考慮した適応的In-Situ可視化

  山岡 義昭, 林 賢悟, 坂本 尚久, 野中 丈士, 吉永 司, 野崎 一徳

  日本機械学会 第97期 流体工学部門 講演会, Nov. 2019, Japanese

  Poster presentation


• 確率的半透明流線可視化向けアンビエントオクルージョン

  藤田 泰之, 坂本 尚久

  第47回 可視化情報シンポジウム, Jul. 2019, Japanese

  Oral presentation


• Visual Causal Exploration with Transfer Entropy Applied to a Severe Rainfall Event

  Naohisa Sakamoto, Jorji Nonaka, Yasumitsu Maejima, Koji Koyamada

  IEEE Pacific Visualization 2019, Apr. 2019, English

  Poster presentation


• BiClustering and Transfer Entropy for the Visual Analysis of Critical Hard ware Failures on the K computer

  Kazuki Koiso, Naohisa Sakamoto, Jorji Nonaka, Fumiyoshi Shoji, Keiji Yamamoto

  IEEE Pacific Visualization 2019, Apr. 2019, English

  Poster presentation


• 深層学習技術を使った可視化画像からのパイプライン推定

  村本 佳希, SAKAMOTO NAOHISA

  第2回ビジュアリゼーションワークショップ, Mar. 2019, Japanese, Domestic conference

  Poster presentation


• 確率的半透明流線可視化向けアンビエントオクルージョン

  藤田 泰之, SAKAMOTO NAOHISA

  第2回ビジュアリゼーションワークショップ, Mar. 2019, Japanese, Domestic conference

  Poster presentation


• ヘッドマウントディスプレイ向け統合可視化基盤システムの開発

  長濱 愛珠咲, SAKAMOTO NAOHISA

  第2回ビジュアリゼーションワークショップ, Mar. 2019, English, Domestic conference

  Poster presentation


• Development of a visual analytics system which can search for the cause of failure interactively

  Kazuki Koiso, Sakamoto Naohisa, Jorji Nonaka

  The 1st R-CCS International Symposium, Feb. 2019, English

  Poster presentation


• 歯茎摩擦音発音シミュレーションにおける口腔内気流と空力音源の in-situ 可視化

  林 賢悟, 吉永司, 野崎 一徳, 野中 丈士, SAKAMOTO NAOHISA

  第 32 回数値流体力学シンポジウム, Dec. 2018, Japanese, Domestic conference

  Oral presentation


• Visual Data Exploration for Large-scale Numerical Simulations on HPC Environments

  Naohisa Sakamoto

  The 27th International Toki Conference on Plasma and Fusion Research, Nov. 2018, English, International conference

  Invited oral presentation


• HIVE: A Cross-Platform, Modular Visualization Ecosystem for Heterogeneous Computational Environments

  Jorji Nonaka, Kenji Ono, Naohisa Sakamoto, Kengo Hayashi, Tomohiro Kawanabe, Fumiyoshi Shoji

  The 2018 Conference on Supercomputing (SC18), Nov. 2018, English, International conference

  Poster presentation


• A Large Data Visualization Framework for SPARC64 fx HPC Systems – Case Study: K Computer Operational Environment

  Jorji Nonaka, Kenji Ono, Naohisa Sakamoto, Kengo Hayashi, Motohiko Matsuda, Fumiyoshi Shoji, Kentaro Oku, Masahiro Fujita, Kazuma Hatta

  The 8th IEEE Symposium on Large Data Analysis and Visualization (LDAV 2018), Oct. 2018, English, International conference

  Poster presentation


• 大規模数値計算向け視覚的因果探索技術

  林 賢悟, 清水 天志, SAKAMOTO NAOHISA, 野中 丈士, 前島 康光, 小山田 耕二

  第46回可視化情報シンポジウム, Sep. 2018, Japanese, Domestic conference

  Oral presentation


• 細胞の表現型特徴を考慮した時空間細胞核形状可視化

  長井 沙也伽, SAKAMOTO NAOHISA, 京田 耕司, 大浪 修一, 小山田 耕二

  第46回可視化情報シンポジウム, Sep. 2018, Japanese, Domestic conference

  Oral presentation


• HPCログデータを使った故障原因探索のための視覚的分析システムの開発

  小磯 一貴, SAKAMOTO NAOHISA, 野中 丈士, 庄司 文由

  第46回可視化情報シンポジウム, Sep. 2018, Japanese, Domestic conference

  Oral presentation


• 234画像重畳技術を使った並列粒子レンダリング

  山岡 義明, SAKAMOTO NAOHISA, 野中 丈士

  第46回可視化情報シンポジウム, Sep. 2018, Japanese, Domestic conference

  Oral presentation


• Cell nucleus visualization with phenotypic characteristics

  Sayaka Nagai, SAKAMOTO NAOHISA, Koji Kyoda, Shuichi Onami

  IEEE Pacific Visualization 2018, Apr. 2018, English, International conference

  Poster presentation


• A Fully Parallel Particle-based Volume Rendering for Large-Scale Unstructured Volume Datasets

  Kengo Hayashi, Yoshiaki Yamaoka, SAKAMOTO NAOHISA, Jorji Nonaka

  IEEE Pacific Visualization 2018, Apr. 2018, English, International conference

  Poster presentation


• HPCログデータを使った故障解析のための視覚的分析技術の開発

  小磯 一貴, SAKAMOTO NAOHISA, 野中 丈士, 庄司 文由

  第1回ビジュアリゼーションワークショップ, Mar. 2018, Japanese, 可視化情報学会, Domestic conference

  Poster presentation


• 234画像重畳技術を使った並列粒子レンダリング

  山岡 義明, 林 賢悟, SAKAMOTO NAOHISA, 野中 丈士

  第1回ビジュアリゼーションワークショップ, Mar. 2018, Japanese, 可視化情報学会, Domestic conference

  Poster presentation


• Parallel Particle-based Volume Rendering with 234Compositor for Large-Scale Unstructured Volume Data Visualization

  Kengo Hayashi, Yoshiaki Yamaoka, SAKAMOTO NAOHISA, Jorji Nonaka

  The 8th AICS International Symposium, Feb. 2018, English, International conference

  Poster presentation


• HPCログデータを使った故障解析のための視覚的分析技術の開発

  小磯 一貴, SAKAMOTO NAOHISA, 野中 丈士, 庄司 文由

  先進的描画装置を用いた可視化情報の研究会, Dec. 2017, Japanese, 核融合科学研究所, Domestic conference

  Oral presentation


• 234画像重畳技術を使った並列粒子レンダリング

  山岡 義明, 林 賢悟, SAKAMOTO NAOHISA, 野中 丈士

  先進的描画装置を用いた可視化情報の研究会, Dec. 2017, Japanese, 核融合科学研究所, Domestic conference

  Oral presentation


• 粒子径調節技術を使った並列粒子ベースボリュームレンダリング

  林 賢悟, SAKAMOTO NAOHISA, 小山田 耕二

  第45回可視化情報シンポジウム, Jul. 2017, Japanese, 可視化情報学会, Domestic conference

  Oral presentation


• 線虫胚の細胞核分裂動態解析のための視覚的分析システムの開発

  長井 沙也伽, SAKAMOTO NAOHISA

  第45回可視化情報シンポジウム, Jul. 2017, Japanese, 可視化情報学会, Domestic conference

  Oral presentation


• Stylized Semi-transparent Streamlines by Stochastic Rendering Approach

  Tomohisa Tanaka, SAKAMOTO NAOHISA

  NICOGRAPH International 2017, Jun. 2017, English, International conference

  Poster presentation


• Flexible visualization framework for head-mounted display system with gesture interaction interface

  Pierre Jarsaillon, SAKAMOTO NAOHISA

  第78回CG・可視化研究会（CAVE研究会）, Jun. 2017, English, Domestic conference

  Oral presentation


• Development of interactive visualization system for volume data using Head-Mounted Display

  Pierre Jarsaillon, Yu Han, SAKAMOTO NAOHISA

  NICOGRAPH International 2017, Jun. 2017, English, International conference

  Poster presentation


• 超大規模ボリュームデータ向けWebベース探索的データ可視化環境

  SAKAMOTO NAOHISA

  第10回金沢コンピュータグラフィックス談話会, Dec. 2016, Japanese, Domestic conference

  Oral presentation


• Integrated Volume Visualization Environment on the Web

  Takashi Shimizu, Naohisa Sakamoto, Jorji Nonaka, Kenji Ono, Koji Koyamada

  International Workshop on In-Situ Infrastructures for Enabling Extreme-scale Analysis and Visualization (ISAV2016), Nov. 2016, English, International conference

  Oral presentation


• KVS: A simple and effective framework for scientific visualization

  SAKAMOTO NAOHISA, Koji Koyamada

  International Conference on Simulation Technology (JSST2016), Oct. 2016, English, International conference

  [Invited]

  Invited oral presentation


• Visualization of Yin-Yang-Zhong Grid Dataset with Particle-based Rendering

  Kazusa Tsubota, SAKAMOTO NAOHISA, KAGEYAMA Akira

  第44回可視化情報シンポジウム, Jul. 2016, Japanese, The Visualization Society of Japan, Domestic conference

  Oral presentation


• Minimizing the Number of Edges via Edge Concentration in Dense Layered Graphs

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  IEEE Pacific Visualization 2016, Apr. 2016, English, International conference

  [Invited]

  Invited oral presentation


• HPCのための可視化、可視化のためのHPC

  Naohisa Sakamoto

  Cyber HPC Symposium 2016, Mar. 2016, Japanese, Cyber Media Center, Osaka University, Domestic conference

  [Invited]

  Nominated symposium


• Particle-based rendering for irrgular volumes with adaptive particle size adjustment technique

  Naohisa Sakamoto, Kun Zhao, Koji Koyamada

  NICOGRAPH 2015, Nov. 2015, Japanese, 大阪, Domestic conference

  Poster presentation


• 認知構造ネットワーク可視化における表示方法のユーザー評価

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  可視化情報全国講演会 (京都 2015), Oct. 2015, Japanese, 可視化情報学会, 京都工芸繊維大学, Domestic conference

  Oral presentation


• Visual analytics system for finding a causal relationship between physical quantities from multivariate volume datasets

  Naohisa Sakamoto, Kun Zhao, Koji Koyamada

  Symposium on Visualization in Data Science (VDS 2015), Oct. 2015, English, Chicago, IL, USA, International conference

  Poster presentation


• 次世代可視化システムの開発

  Naohisa Sakamoto

  STEシミュレーション研究会 - エクサスケールに向けて -, Sep. 2015, Japanese, 京都大学学術情報メディアセンター 北館, Domestic conference

  [Invited]

  Invited oral presentation


• 融合可視化システムへのOpenGL合成技術の適用

  Hideo Miyachi, Naohisa Sakamoto, Koji Koyamada

  第43回可視化情報シンポジウム, Jul. 2015, Japanese, 可視化情報学会, 工学院大学, Domestic conference

  Oral presentation


• 男子ラクロスの戦術改善に資する選手向け可視化システムの開発

  Shinsuke Imai, Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  第43回可視化情報シンポジウム, Jul. 2015, Japanese, 可視化情報学会, 工学院大学, Domestic conference

  Oral presentation


• 感性工学に基づいた可視化アプリケーション評価手法の提案

  Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  第43回可視化情報シンポジウム, Jul. 2015, Japanese, 可視化情報学会, 工学院大学, Domestic conference

  Oral presentation


• Word cloud を用いた評価構造の文章可視化

  Keita Ozawa, Koji Koyamada, Naohisa Sakamoto, Yosuke Onoue

  第43回可視化情報シンポジウム, Jul. 2015, Japanese, 可視化情報学会, 工学院大学, Domestic conference

  Oral presentation


• Visualization of Tsunami Simulation Data with Particle-based Rendering

  Kun Zhao, Satoshi Nakada, Naohisa Sakamoto, Koji Koyamada, Kohei Murotani, Seiichi Koshizuka

  第43回可視化情報シンポジウム, Jul. 2015, English, 可視化情報学会, 工学院大学, Domestic conference

  Oral presentation


• Using Interactive Particle-based Rendering to Visualize a Large-scale Unstructured Volume with Mixed Cell Types

  Kun Zhao, Naohisa Sakamoto, Koji Koyamada

  IEEE Pacific Visualization 2015, Apr. 2015, English, Hangzhou, China, International conference

  Poster presentation


• Text based visualization of evaluation structures using tag clouds

  Keita Ozawa, Yosuke Onoue, Nobuyuki Kukimoto, Naohisa Sakamoto, Koji Koyamada

  IEEE Pacific Visualization 2015, Apr. 2015, English, Hangzhou, China, International conference

  Poster presentation


• Lacrosse Vis: a visual analytics system for lacrosse players

  Shinsuke Imai, Yosuke Onoue, Naohisa Sakamoto, Nobuyuki Kukimoto, Koji Koyamada

  IEEE Pacific Visualization 2015, Apr. 2015, English, Hangzhou, China, International conference

  Poster presentation


• Interactive exploration and verification of latent factor in large scale biophysical networks

  Yosuke Onoue, Naohisa Sakamoto, Koji Koyamada

  Symposium on Visualization in Data Science (VDS 2015), Apr. 2015, English, Chicago, IL, USA, International conference

  Poster presentation

• Information Processing Society of Japan

  Apr. 2022 - Present


• Asociation for Computing Machinery

  Sep. 2017 - Present


• IEEE Computer Society

  Feb. 2011 - Present


• Japan Society for Simulation Technology

  May 2010 - Present


• The Visualization Society of Japan

  Jun. 2007 - Present


• The Institute of Electronics, Information and Communication Engineers

  Oct. 1998 - Present

• KVS: Kyoto Visualization System

  Naohisa Sakamoto

  Kyoto Visualization System (KVS) is a multi-platform, open-source C++ library for developing scientific visualization applications. KVS provides various classes and interfaces, such as isosurace extraction, streamlines and volume rendering, to visualize medical data obtained by computerized tomography or magnetic resonance imaging, numerical data from computational fluid dynamics and so on.

• エージェントカメラ群による新しいin situ可視化

  陰山 聡, 坂本 尚久

  日本学術振興会, 科学研究費助成事業 基盤研究(B), 基盤研究(B), 神戸大学, 01 Apr. 2022 - 31 Mar. 2027


• Ultra-High-Resolution Visualization of 3D Scanned Big Data for Assisting Recognition of Large-Scale 3D Structures in the Real World

  田中 覚, 陳 延偉, 矢野 桂司, 李 亮, 長谷川 恭子, 伊達 宏昭, 坂本 尚久, 山口 欧志, 坂野 雄一

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Grant-in-Aid for Scientific Research (A), Ritsumeikan University, 05 Apr. 2021 - 31 Mar. 2025


• Smart in-situ visualization for large-scale numerical calculations aiming at efficient knowledge acquisition

  坂本 尚久, 陰山 聡, 野中 丈士

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kobe University, 01 Apr. 2020 - 31 Mar. 2024

  本研究では、大規模数値シミュレーションによって計算される数値データに対して、時間・空間・変数に関する３つの指標を設定することによって可視化すべき時空間領域を効率よく推定し、In-situ可視化における画像化時間の短縮だけでなく、数値データからの科学的知見を獲得するまでの時間を短縮することができるスマートIn-situ可視化を実現することである。 本年度は、時間を評価基準とした適応的時間サンプリング手法を開発し、空間を評価基準とした最適視点推定手法に着手した。 適応的時間サンプリング手法では、解析対象とする物理量の空間分布の時間変化を、時刻の異なる二つの確率分布の差として計算することで、状態変化の重要度として指標化した。そして、その大きさに応じて可視化する時間間隔を適応的に変更することで、シミュレーションにおいて興味がある重要な時空間領域の特徴を捉えつつ、可視化処理回数を大幅に削減することができた。実験では、本手法を歯茎摩擦音の発音シミュレーションに適用し、予め設定する評価時間間隔と画像削減率との関係を明らかにし、およそ半分程度の処理回数で重要な変化を可視化することに成功した。 最適視点推定手法では、可視化する時間領域において、対象とする物理量の空間変化を画像にとらえるために、投影画像の差に着目した視点選択手法の開発に着手した。本開発では、データを内包する立方体の各頂点に視点を設定し、その視点から可視化される画像間の差をもとに再帰的に空間分割を行い可視化することで、重要な変化が画像化できる重点領域を推定することができる手法を実装した。特に、本年度は、多視点In-situ可視化処理を効率よく実装するために、視線と視点の配置を自由に組み合わせることができるフレームワークを開発した。本フレームワークにより、次年度以降に予定している要素技術の統合および評価実験の効率化が期待できる。


• Estimation of Physical Pathology of Articulatory Disorder Using Articulatory Simulator and Medical Information

  野崎 一徳, 野原 幹司, 坂本 尚久, 吉永 司, 和田 成生, 山田 朋美, 笹井 正思, 阪井 丘芳

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Osaka University, 01 Apr. 2019 - 31 Mar. 2022

  非侵襲的に小児から老人まで構音時の気道形状を観察し、計測することは、構音障害を同定する際に有効であろうと考えられる。そこで本年度は、超音波画像撮影装置を導入した。所属機関倫理審査を受けたのち、複数人の健常人に対して構音時の気道形状の変化を観察した。さらに、舌癌既往患者の構音時の気道の観察を行った。 構音障害の要因を明らかにするため、構音時の舌運動に関する研究を行った。歯科において最も問題となる音素である[s]音に関して、昨年度の物理実験では母音との調音結合に要する時間に関わらず、一定の時間[s]音が発生し続ける現象が明らかとなったが、本年度では圧縮性のナビエ・ストークス方程式を用いた数値解析によって、調音結合時の気道内での流れと、そこから生じる音源成分、そして伝播する圧力波を導出し、遠方場での音のスペクトル特性がよく一致することを確認した。さらに[s]音を含む調音結合では上顎中切歯口蓋側面において縦渦が生じていることが、可視化された。 舌筋繊維を考慮した有限要素法による舌機能モデルの構築を行った。ヒトにおける舌突出を実現するために、初期条件に重力を与えることで、前方への舌突出再現性が向上することを確かめた。 口唇口蓋裂や舌癌既往の患者に関しては、自らの声質で会話を成立させたいという願望があり、ボイスコマンド等の音声認識の利活用への期待が大きい。３名の患者にATR503文を朗読してもらい、その音声を用いて、ニューラルネットワークを用いた自己教師あり学習を行った。その結果、患者の音声特性を反映した音声認識の実現可能性に関して有効性が確かめられた。


• Development of particle-based data exploration environment for large-scale dataset

  Sakamoto Naohisa

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Grant-in-Aid for Scientific Research (C), Kobe University, 01 Apr. 2017 - 31 Mar. 2020, Principal investigator

  In this research, we developed a particle-based data exploration environment that allows exploratory visualization of large-scale numerical simulation data computed on a supercomputer through a Web browser without transfering the volume dataset to a visualization terminal at the local side. In this development, we have extended the particle rendering method developed by the principal investigator to realize efficient parallel processing on a supercomputer. In addtion, we developed a semi-automatic construction method for visualization pipelines required to describe visualization processing procedures, and realized the construction of an exploratory data analysis environment for large-scale data by operating them via a web browser.

  Competitive research funding


• Development of analysing a folded book using 3-D data visualization techniques

  KOYAMADA Koji, NAKANISHI Tohru, SAKAMOTO Naohisa

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory), Grant-in-Aid for Challenging Research (Exploratory), Kyoto University, 30 Jun. 2017 - 31 Mar. 2019

  In this project, we developed a technique to recognize one page from the volume data of the booklet, even if the pages constituting the booklet are not necessarily flat. Specifically, using the Active Grid method developed by us, it was possible to map the space area corresponding to the booklet from the given 3D CT volume data to a rectangular grid. Active Grid assumes a three-dimensional grid model and deforms each grid so as to fit in a three-dimensional region inside the volume data.


• Construction of integrated particle rendering environment for large scale data visualization

  KOYAMADA Koji

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kyoto University, 01 Apr. 2014 - 31 Mar. 2017

  The purpose of this research is to develop a scalable integrated particle rendering (PBR) technology to realize interactive volume rendering for large scale simulation results. In order to confirm its effectiveness, we have constructed an integrated PBR environment consisting of image-based PBR(IPBR) and object-based PBR(OPBR). In order to verify the effectiveness of this integrated PBR environment, we confirmed that IPBR and OPBR are connected seamlessly. Next, it was confirmed that the rendering result was displayed smoothly for the change of the transfer function. Finally, we confirmed the scalability of the rendering process in large scale parallel environment.


• X線撮像と層データ解析を用いて古文献にも適用可能な非侵襲的手法による冊子体コンテンツ可視化技術の開発

  坂本 尚久

  研究成果展開事業（マッチングプランナー プログラム）, 2016, Principal investigator

  Competitive research funding


• マッチングプランナー「X線撮像と層データ解析を用いて古文献にも適用可能な非侵襲的手法による冊子体コンテンツ可視化技術の開発」

  坂本 尚久

  科学技術振興機構, 研究成果展開事業 マッチングプランナープログラム 探索試験, 2015, Principal investigator

  Competitive research funding


• Development of a remote collaboration environment using a particle-based volume rendering technique

  KOYAMADA Koji, SAKAMOTO Naohisa, DATE Susumu, EBARA Yasuo

  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Grant-in-Aid for Scientific Research (B), Kyoto University, 2009 - 2011

  When a particle-based volume rendering is applied to a volume dataset, a huge number of particles may be generated if some transfer function is specified. It is pointed out that there is a possibility that the decrease of the frame rate may hamper an effective remote collaboration work. In this research we propose a technique for decreasing the number of particles by modifying the transfer function so that the feature of the transfer function can be kept and enlarging the radius of the particles and confirmed their effectiveness. In addition, we developed a middleware to divide a given volume dataset on the data server for the efficient data communication and confirmed its effectiveness.


• Development of a remote collaboration environment using a particle-based volume rendering technique

  Koji KOYAMADA

  Ministry of Education, Culture, Sports, Science and Technology, Grants-in-Aid for Scientific Research(基盤研究(B)), 2009 - 2011

  When a particle-based volume rendering is applied to a volume dataset, a huge number of particles may be generated if some transfer function is specified. It is pointed out that there is a possibility that the decrease of the frame rate may hamper an effective remote collaboration work. In this research we propose a technique for decreasing the number of particles by modifying the transfer function so that the feature of the transfer function can be kept and enlarging the radius of the particles and confirmed their effectiveness. In addition, we developed a middleware to divide a given volume dataset on the data server for the efficient data communication and confirmed its effectiveness.

  Competitive research funding

• 粒子レンダリング処理装置、粒子レンダリング方法及びコンピュータプログラム

  小山田耕二, 坂本尚久

  特願2016-573357, 01 Feb. 2016, 国立大学法人京都大学, WO2016-125754, 11 Aug. 2016, 特許第6719774号, 19 Jun. 2020

  Patent right

  IRI


• 書物電子化方法および書物電子化装置

  小山田耕二, 中西徹, 坂本尚久

  特願2016-014858, 27 Jan. 2017, シャープ株式会社, 国立大学法人京都大学, WO2017-131184, 03 Aug. 2017

  Patent right

  IRI


• 3次元形状復元システムおよび方法

  宮地 英生, 坂本 尚久

  特願2001-340222, 06 Nov. 2001, 株式会社クボタ, 株式会社ケイ・ジー・ティー, 特開2003-141565, 16 May 2003

  Patent right

  IRI