Details of a Researcher - Fujishiro, Issei

Papers - Fujishiro, Issei

Division display 241 - 260 of about 423 ／ All the affair displays >>

Glasses-free 3D imaging by optic illusion with orthogonally-arranged multi-displays

井阪　建，藤代一成

Visual Computing/グラフィクスとCAD合同シンポジウム2015 DVD予稿集 (画像電子学会) 2015.06

Research paper (conference, symposium, etc.), Joint Work, Accepted

Motion puppetry taking skeletal similarity into account

KANEKO Norihide, TAKAHASHI Reo, FUJISHIRO Issei

Proceedings of the 28th International Conference on Computer Animation and Social Agents (CASA2015) (Computer Graphics Society) 2015.05

Research paper (international conference proceedings), Joint Work, Accepted

Motion retargeting is a well-known method for generating character animations in computer graphics, where the original motion of an actor can be transferred to an avatar with a different skeletal structure and/or limbs' length. A specific type of retargeting for manipulating various avatars interactively is referred to as puppetry. However, previous learning-based works of puppetry cannot be said to be fully interactive, or require a large amount of metadata about the avatar's skeleton as well as training data of motions. Thus, we attempted to integrate existing methods by taking into account skeletal similarity between an actor and his/her avatar, to come up with an interactive and intuitive motion retargeting method that only requires a relatively small amount of training animations together with simple input metadata. Moreover, by classifying avatar's body parts in a procedural manner, a more flexible motion puppetry was realized, where the system user is allowed to specify desirable part-to-part correspondences.

Implicit formulation for SPH-based viscous fluids

TAKAHASHI Tetsuya, DOBASHI Yoshinori, FUJISHIRO Issei, NISHITA Tomoyuki, LIN Ming C.

Computer Graphics Forum (Eurographics) 34 ( 2 ) 493 - 502 2015.05

Research paper (scientific journal), Joint Work, Accepted, ISSN 1467-8659

We proposed a stable and efficient particle-based method for simulating highly viscous fluids that can generate coiling and buckling phenomena and handle variable viscosity. In contrast to previous methods that use explicit integration, our method uses an implicit formulation to improve the robustness of viscosity integration, therefore enabling use of larger time steps and higher viscosities. We use Smoothed Particle Hydrodynamics to solve the full form of viscosity, constructing a sparse linear system with a symmetric positive definite matrix, while exploiting the variational principle that automatically enforces the boundary condition on free surfaces. We also proposed a new method for extracting coefficients of the matrix contributed by second-ring neighbor particles to efficiently solve the linear system using a conjugate gradient solver. Several examples demonstrated the robustness and efficiency of our implicit formulation over previous methods and illustrated the versatility of our method.

Access to Document (DOI)

Biclustering multivariate data for correlated subspace mining

WATANABE Kazuho, WU Hsiang-Yun, NIIBE Yusuke, TAKAHASHI Shigeo, FUJISHIRO Issei

Proceedings of IEEE Pacific Visualization Symposium 2015 (IEEE Computer Society) 287 - 294 2015.04

Research paper (international conference proceedings), Joint Work, Accepted, ISSN 2165-8765

Exploring feature subspaces is one of promising approaches to analyzing and understanding the important patterns in multivariate data. If relying too much on effective enhancements in manual interventions, the associated results depend heavily on the knowledge and skills of users performing the data analysis. This paper presented a novel approach to extracting feature subspaces from multivariate data by incorporating biclustering techniques. The approach has been maximally automated in the sense that highly-correlated dimensions are automatically grouped to form subspaces, which effectively supports further exploration of them. A key idea behind our approach lies in a new mathematical formulation of asymmetric biclustering, by combining spherical k-means clustering for grouping highly-correlated dimensions, together with ordinary kmeans clustering for identifying subsets of data samples. Lower dimensional representations of data in feature subspaces are successfully visualized by parallel coordinate plot, where we project the data samples of correlated dimensions to one composite axis through dimensionality reduction schemes. Several experimental results of our data analysis together with discussions were provided to assess the capability of our approach.

Access to Document (DOI)

Development of a Skirt Pattern Design System Based on 3D Human Body Measurement Data Analysis

YAMAMOTO Takami, NAKAYAMA Masanori, KATSURA Rui, SAKAMOTO Akira, FUJISHIRO Issei

The Journal of the Society for Art and Science (The Society for Art and Science) 14 ( 1 ) 9 - 19 2015.03

Research paper (scientific journal), Joint Work, Accepted, ISSN 1347-2267

This paper presents a design system encompassing the process from high-precision design to the production of a skirt prototype based on the deployment of design by analysis of 3D body data gathered with a 3D scanner. This system is characterized in that (1) it allows the generation of accurate reference cross-sectional data from polygonal data of the body according to an intended design, (2) automatic drawing functions by the draping method using a reference cross-sectional data, and (3) production of patterns capable of accommodating various body types , As a result, individual 3D body data analysis can be performed rapidly and wear comfortable skirt patterns that fit the body contours can be obtained in a shorter period of time.

骨格の類似度を考慮したモーションパペトリー

KANEKO Norihide,TAKAHASHI Reo,FUJISHIRO Issei

映像表現・芸術科学フォーラム2015 (映像情報メディア学会・画像電子学会・芸術科学会) 2015.03

Joint Work

SeeGroove：可視化を介したグルーヴの学習支援

HAGA Naoki,NAKAYAMA Masanori,FUJISHIRO Issei

映像表現・芸術科学フォーラム2015 (映像情報メディア学会・画像電子学会・芸術科学会) 2015.03

Joint Work

位置ベース力学に基づく布の折り目シミュレーション

KITAMI Sho,FUJISHIRO Issei

映像表現・芸術科学フォーラム2015 (映像情報メディア学会・画像電子学会・芸術科学会) 2015.03

Joint Work

マルチスコピックビューアとその選択的時空間ブラウジングへの応用

SANO Takahiro,FUJISHIRO Issei

映像表現・芸術科学フォーラム 2015 (映像情報メディア学会・画像電子学会・芸術科学会) 2015.03

Joint Work

Splashing liquids with ambient gas pressure

UEDA Kazuhide, FUJISHIRO Issei

Proceedings of ACM SIGGRAPH Asia 2014 Technical Briefs (ACM) 2014.12

Research paper (international conference proceedings), Accepted

Splashing occurs when a liquid drop hits the solid or fluid surface at a high velocity. The drop after the impact spreads and forms a corona with a thickened rim, which first develops annular undulations and then breaks into secondary droplets. We have many chances to see splashes in our daily life, e.g., milk crown, splashing paint, and raindrops falling onto a pool, whose characteristics of deformation have a significant impact on the visual reality of the phenomena. Many experimental studies have been conducted to find criteria on when splashing would occur, but the physical mechanisms of splashing are still not completely understood. It was only recently discovered that ambient gas pressure is a principal factor for creating such a splash. In this paper, therefore, we newly incorporate the ambient gas pressure effect into the Navier-Stokes equations through SPH fluid simulation for representing more accurate splashing dynamics. Our experiments demonstrated that the new approach requires very little additional computing cost to capture realistic liquid behaviors like fingering, which have not previously been attained by SPH nor most schemes for fluid simulation.

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変奏様式に着目した変奏曲の可視化システムの構築

村岡遼太，藤代一成

音楽情報科学研究会第105回研究発表会 (情報処理学会) 2014.11

Joint Work

変奏曲とは，主題とよばれる素材を示して，その後主題を変化させた変奏を複数並べていくクラシック音楽の形式の一つである．変奏は主題の各要素に対して行われるが，変奏様式によって主題がどのように変化しているかを判別するには音楽理論の知識が不可欠である．そこで本研究では，音楽知識をもたないユーザにも，変奏様式による主題の変化をわかりやすく提示することを目的として，変奏曲の構造を可視化する手法を提案する．入力にはMIDI(Musical　Instrument Digital Interface) データを用いて，変奏曲を3次元空間内に可視化し，構造をより理解しやすくするための対話的機能を提供するシステムを開発した．そこでは，各変奏様式と3 次元空間内のオブジェクトを対応付ける独自のマッピングを用いている．さらに独自のマッピングに関するユーザテストを行い，提案したマッピングの有効性が示された．

IFWB：没入型映像インスタントメーカ

ISAKA Takeru, FUJISHIRO Issei

NICOGRAPH2014 (芸術科学会) 2014.11

Joint Work

本論文では, 奥行きのある構図をもつ画像を1枚入力すると，ユーザ入力を必要とすることなく即座に3次元情報を付与し, ユーザ頭部の位置変化に合わせて変化する没入型映像を生成するシステムIFWBを提案する．実際のターゲット環境としてスマートフォンやタブレット端末などの軽薄短小なデバイスを想定しており, カメラと同じような感覚で, いつでもどこでも使うことができる.

Development of a pants pattern design system based on 3D human body measurement data analysis

YAMAMOTO Takami, NAKAYAMA Masanori, KATSURA Rui, SAKAMOTO Akira, FUJISHIRO Issei

Proceedings of the 4th IIEEJ International Workshop on Image Electronics and Visual Computing Workshop 2014 (IIEEJ) 4B-2 2014.10

Accepted

In this paper, we propose a pants pattern design covering its highly precise design to pattern making by analyzing human body measurement data acquired with a 3D scanner. This system is characterized by: (1) being able to analyze data required for the design of pants patterns using an improved 3D human body measurement analysis application, and (2) being provided with automatic pants drafting functions installed in an apparel CAD system using 3D human body measurement data. As a result, individual 3D human body measurement data can be analyzed both accurately and rapidly, thereby enabling pants patterns that are comfortable and properly fit the physique of the wearer to be obtained in a short period of time.

画像電子学会誌ビジュアルコンピューティング特集号

藤代一成（ゲスト編集委員長）

(画像電子学会) 2014.08

Mood-Learning Public Display: Adapting content design evolutionarily through viewers' involuntary gestures and movements

NAGAO Ken, FUJISHIRO Issei

IEICE Transactions on Information and Systems (IEICE) E97-D ( 8 ) 1991 - 1999 2014.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 1745-1361

Due to the recent development of underlying hardware
technology and improvement in installing environments, public display has been becoming more common and attracting more attention as a new type of signage. Any signage is required to make its content more attractive to its viewers by evaluating the current attractiveness on the fly, in order
to deliver the message from the sender more effectively. However, most previous methods for public display require time to reflect the viewers' evaluations. In this paper, we present a novel system, called Mood-Learning Public Display, which automatically adapts its content design. This system
utilizes viewers' involuntary behaviors as a sign of evaluation to make the content design more adapted to local viewers' tastes evolutionarily on site. The system removes the current gap between viewers' expectations and the content actually displayed on the display, and makes efficient mutual transmission of information between the cyberworld and the reality.

Access to Document (DOI)

Toplologically-Based Visual Data Mining for 2D Unsteady Flow Fields

TAKESHIMA Yuriko, FUJISHIRO Issei, TAKAHASHI Shigeo, HAYASE Toshiyuki

The Journal of the Institute of Image Electronics Engineers of Japan (The Institute of Image Electronics Engineers of Japan) 43 ( 3 ) 357 - 366 2014.07

Research paper (scientific journal), Joint Work, Accepted, ISSN 1348-0316

Vortices can be considered as one of the most fundamental features of a fluid, and play an indispensable role in the understanding of dynamics of underlying flows. However, it is difficult to capture time-varying, complex vortex structures consistently with traditional trial-and-error visualization methods because flow fields are changing drastically in unsteady fluid datasets. In this paper, we therefore propose a topologically-based approach to visual data mining of unsteady flow field datasets. Since it is well-known that the vortex centers are located at local minima in the 2D associated pressure field, we identify their locations by extracting critical points of the field, segmenting it into sub-regions each of vortices using topological information, and trace the vortices in the unsteady datasets. In addition, we propose a novel transfer function design which employs constant hue assignment and a stepwise brightness setting for timeseries datasets. The design of transfer function allows users to understand the global change in the flow fields from the hue value as well as the behavior of the vortices even if the flow fields are changing drastically. The feasibility of our approach is illustrated with an application to practical datasets for Karman vortex street, which are taken from measurement-integrated simulation of the Hybrid Wind Tunnel.

Spectral-based contractible parallel coordinates

NOHNO Koto, WU Hsiang-Yun, WATANABE Kazuho, TAKAHASHI Shigeo,FUJISHIRO Issei

Proceedings of iV2014 (IEEE Computer Society) 7 - 12 2014.07

Research paper (international conference proceedings), Joint Work, Accepted

This paper presents a method of alleviating such visual clutter by contracting multiple axes through the analysis of correlation between every pair of variables. In this method, we first construct a graph by connecting axis nodes with an edge weighted by data correlation between the corresponding pair of dimensions, and then reorder the multiple axes by projecting the nodes onto the primary axis obtained through the spectral graph analysis. This allows us to compose a dendrogram tree by recursively merging a pair of the closest axes one by one. Our visualization platform helps the visual interpretation of such axis contraction by plotting the principal component of each data sample along the composite axis. Smooth animation of the associated axis contraction and expansion has also been implemented to enhance the visual readability of behavior inherent in the given high-dimensional datasets.

Access to Document (DOI)

Fast simulation of viscous fluids with elasticity and thermal conductivity using position-based dynamics

TAKAHASHI Tetsuya, NISHITA Tomoyuki, FUJISHIRO Issei

Computers & Graphics (Elsevier) 43 21 - 30 2014.07

Research paper (scientific journal), Joint Work, ISSN 0097-8493

In this paper, we propose a novel particle-based Lagrangian method for efficiently simulating viscous fluids by adopting position-based constraints. Our method uses the geometric configuration of particles for the positional constraints to approximate the dynamics of viscous fluids using position-based dynamics; thus the method can plausibly generate their motions while allowing for the use of much larger time steps than those previously adopted in the viscous fluid simulations. We also propose an associated boundary-handling scheme for position-based fluids to precisely specify boundary conditions for the constraints. Additionally, we reproduce elastic deformations of materials by controlling the constraints and incorporate thermal conduction into our framework to simulate resultant changes in particle properties and phase transition in the materials. By adjusting parameters, our method can encompass complex motions of fluids with different properties in a unified framework. Several examples demonstrate the effectiveness as well as versatility of our method.

Access to Document (DOI)

頭髪状物体の描画に対応するアンチエイリアシング処理されたリアルタイムシャドウイング

ISAKA Takeru, FUJISHIRO Issei, MATSUOKA Toru

Visual Computing/グラフィクスとCAＤ合同シンポジウム2014 (画像電子学会・情報処理学会・映像情報メディア学会) 2014.06

Joint Work

単一画像からの運動視差立体視の実現

ISAKA Takeru, FUJISHIRO Issei

Visual Computing/グラフィクスとCAＤ合同シンポジウム2014 (画像電子学会・情報処理学会・映像情報メディア学会) 2014.06

Joint Work

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