• Title/Summary/Keyword: Shape-Generation

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Shape Design Optimization of High-Speed Air Vehicles Using Non-Uniform Rational B-Splines (NURBS 곡선을 이용한 고속비행체 최적형상설계)

  • Kim Sang-Jin;Lee Jae-Woo;Byun Yung-Hwan;Kim Myung-Seong
    • 한국전산유체공학회:학술대회논문집
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    • 2001.05a
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    • pp.72-77
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    • 2001
  • The computational efficiency of an shape optimization procedure is highly dependent upon the proper selection of shape representation methods and design variables. In this study, shape functions, Bezier and NURBS(non-uniform rational B-splines) curves are selected as configuration generation methods and their efficiencies on the nose shape design of high-speed air vehicles, are compared. The effects of the number of control points, weighting factors and the optimization methods when utilizing the NURBS curves, are investigated. By implementing Bezier and NURBS curves, shapes having lower drag than the optimization case utilizing the shape functions, were obtained, hence it was demonstrated that these curves have better capability in representing the configuration. Efforts will be given to improve the convergence behavior when utilizing the NURBS, hence to reduce the number of Navier-Stokes analysis calculations.

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A Study on the Cutting Pattern Determination for Fabric Structures (막 구조물의 재단 패턴 결정에 관한 연구)

  • Choi, Ho;Lee, Jang-Bog;Kim, Jae-Yeol;Sur, Sam-Uel;Kwon, Taek-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1998.10a
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    • pp.266-273
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    • 1998
  • The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions: (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, after shape finding analysis, cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

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2D Game Image Color Synthesis System Using Convolutional Neural Network (컨볼루션 인공신경망을 이용한 2차원 게임 이미지 색상 합성 시스템)

  • Hong, Seung Jin;Kang, Shin Jin;Cho, Sung Hyun
    • Journal of Korea Game Society
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    • v.18 no.2
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    • pp.89-98
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    • 2018
  • The recent Neural Network technique has shown good performance in content generation such as image generation in addition to the conventional classification problem and clustering problem solving. In this study, we propose an image generation method using artificial neural network as a next generation content creation technique. The proposed artificial neural network model receives two images and combines them into a new image by taking color from one image and shape from the other image. This model is made up of Convolutional Neural Network, which has two encoders for extracting color and shape from images, and a decoder for taking all the values of each encoder and generating a combination image. The result of this work can be applied to various 2D image generation and modification works in game development process at low cost.

Development of "ZIGTECHnology" Apparel for Body Shape Renovation of New Senior Life Generation

  • Cha, Su-Joung
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.11
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    • pp.157-166
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    • 2020
  • In this study, I tried to develop ZIGTECHnology clothing for renovation that can correct the body shape of elderly women according to aging and delay the change of body shape. Develop and suggest corrective clothing for elderly women with easy movement that can alleviate symptoms and delay changes in body shape by analyzing body types for each symptom, such as bending of shoulders, back and waist caused by aging and diseases such as spinal curvature. As a result of the wear evaluation of the developed ZIGTECHnology clothing designs 1, 2, and 3, in terms of functionality, Design 1 was evaluated as excellent by reducing the back angle by 3.17°, but design 3 was evaluated as the most excellent considering the fit. In the clothing of elderly women, the need for clothing that complements physical shortcomings increases, so it is thought that continuous development of body shape relief devices should be made.

Discussion on Optimal Shape for Wave Power Converter Using Oscillating Water Column (진동수주형 파력발전구조물의 최적형상에 대한 검토)

  • Lee, Kwang-Ho;Park, Jung-Hyun;Baek, Dong-Jin;Cho, Sung;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.5
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    • pp.345-357
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    • 2011
  • Recently, as part of diversifying energy sources and earth environmental issues, technology development of new renewable energy using wave energy is actively promoted and commercialized around Europe and Japan etc. In particular, OWC(Oscillating Water Column) wave power generation system using air flow induced by vertical movement of the water surface by waves in an air-chamber within caisson is known as the most efficient wave energy absorption device and therefore, is one of the wave power generation apparatus the closest to commercialization. This study examines air flow velocity, which operates turbine(Wells turbine) directly in oscillating water column type wave power generation structure from two-and three-dimensional numerical experiments and discusses optimal shape of oscillating water column type wave power generation structure by estimating the maximum flow rate of air according to change in shape. The three-dimensional numerical wave flume was applied in interpretation for this study which is the model for the immiscible two-phase flow based on the Navier-Stokes Equation. From this, it turned out that size of optimal shape appears differently according to the incident wave period and air flow is maximized at the period where minimum reflection ratio occurs.

Obstacle Avoidance by the Subgoal Generation Using the Infrared Sensors (적외선 센서를 이용한 서브 골 생성에 의한 장애물 회피)

  • Nakazawa, Kazuki;Yang, Dong-Hoon;Kim, Il-Teak;Hong, Suk-Kyo
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.490-492
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    • 2004
  • This paper presents an obstacle avoidance of a mobile robot by the subgoal generation using infrared sensors. When an obstacle appears on the path which the robot is moving forward the robot has to get information, such as distance between the robot and the obstacle and the shape of the obstacle for avoidance behavior. Our collision avoidance algorithm needs the only distance between the robot and the obstacles. The distances are used for subgoal generation. Simulation results show that a robot can go to the goal, carrying out subgoal generation and avoiding obstacles.

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A Study on the Electrical Characteristics of Heat-generation Mortar mixing Graphite (흑연을 혼합한 발열모르타르의 전기적 특성에 관한 연구)

  • Park, Sang-Jun;Won, Cheol;Lee, Sang-Soo;Kwon, Yeog-Ho;Park, Chil-Lim
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.137-142
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    • 1997
  • From the results of study on the electrical characteristics of heat-generation mortar used graphite as fine aggregates is summerized as following. The primary purpose of this study is the mixing ratio of graphite (35%, 50%/Sg), curing conditions (autoclave, steam, surface, underwater) and shape change (length, section of the electric heat-generation mortar). In case of the test condition with the steam curing condition appearance to most excellent heat-generation reproducibility. And temperature a coefficient of electric heat-generation mortar change from is in inverse proportion to the temperature a coefficient of direct proportion as the ratio of graphite mixing increased.

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Grid Generation about Full Aircraft Configuration Using Interactive Grid Generator (상호 대화형 격자생성 환경을 이용한 항공기 전기체 격자계 생성)

  • Kim Y. S.;Kwon J. H.
    • 한국전산유체공학회:학술대회논문집
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    • 1999.11a
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    • pp.145-151
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    • 1999
  • An Interactive grid generation program(KGRID) with graphical user interface(GUI) has been improved. KGRID works on the UNLX environment and GUI has been implemented with OSF/Motif and X Toolkit and the graphics language is Open GL for visualization of the 3D objects. It supports more convenient user environment to generate 2D and 3D multi-block structured grid systems. It provides various useful field grid generation methods, which are the algebraic methods, the elliptic partial differential equations method and the predictor-corrector method. It also supports 3D surface grid generation with NURBS(Non-Uniform Rational B-Spline) and various stretching functions to control grid points distribution on curves and surfaces. And some menus are added to perform flexible management, for the objects. We generated surface and field grid system about full aircraft configuration using KGRID. The performance and stability of the KGRID is verified through the generation of the grid system about a complex shape.

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Names and the Journey to Define a Multicultural Identity in Jhumpa Lahiri's The Namesake

  • Ahn, Laura
    • American Studies
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    • v.42 no.1
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    • pp.99-132
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    • 2019
  • Like many other Asian American writers, Jhumpa Lahiri writes stories that capture the experiences of immigrant families in America. What sets The Namesake apart is that Lahiri cleverly uses the names of her characters to shape their individual lives and futures not just as a first or second generation immigrant, but as people who are more than what that labelling connotes. Although the struggle faced by Ashoke and Ashima to hold on and adapt as first generation immigrants is contrasted with the search for identity among second generation immigrants seen primarily through the experiences of their children Gogol and Sonia, Lahiri uses their struggles as an immigrant family to serve as a starting point for each member of the Ganguli family to find their own identities and understandings of who they are as individuals apart from their race, history or cultural heritage so that they may truly be "without borders."

A Study on the Automatic Design of 4D Printing to Follow the Target Shape (목표 형상을 추종하는 4D 프린팅 자동 설계에 관한 연구)

  • Ham, Sungil;Lee, Yong-Gu
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.3
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    • pp.306-312
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    • 2016
  • In general, the shape of a 3D printed object is not to be changed after the generation. Most changes, for example, contraction of a molten polymer after cooling is thought to be undesirable. 4D printing however tries to make benefit of a shape change after the part is generated. The shape change is required to be controllable in response to an external stimuli. These artifacts from 4D printing are called kinetic components which are defined as structures formed by combining inert materials and smart materials that change under certain stimuli. We propose a design software that can systematically calculate inert links with smart joints to follow the shape of the target design.