• Title/Summary/Keyword: two-dimensional shapes

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Effects of Background Depth Information on the Judgment of Two-dimensional Shapes (배경 깊이정보가 이차원 자극의 형태 판단에 미치는 영향)

  • Kim, Young-Geun;Shin, Hyun-Jung
    • Korean Journal of Cognitive Science
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    • v.17 no.4
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    • pp.287-301
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    • 2006
  • Two experiments were performed to investigate effects of background depth information on the judgment of two-dimensional shapes, using the Posner et al.'s(1969) physical match task. In both experiments, the focus was on whether the background depth information affects the decisions of physical shape sameness of two letters or figures presented successively. In Experiment 1, artificially constructed rues of linear perspective and texture gradient were used, whereas cues contained in a real road situation were used in Experiment 2. The results of both experiments showed that the depth cues affect the perception of two-dimensional shapes. That is, when two stimuli of the same physical shape were likely to be perceived differently due to the given depth cues, response accuracies('yet' in this case) decreased and reaction tines of physical match increased. And when two stimuli of the different physical shape were likely to be perceived the same due to the given depth cues, response accuracies('no' in this case) decreased and reaction times of physical match increased likewise. These results wert discussed in terms of some conceptual methodological problems of the previous studies on the shape constancy and the directions of future research.

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A Generative Design Algorithm to Generate 3D shapes Using 2D Images (2차원 이미지로 3차원 형태를 생성하는 생성적 디자인 알고리듬)

  • Kim, Hyeon Ji;Chung, Yun Chan
    • Design Convergence Study
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    • v.15 no.6
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    • pp.229-241
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    • 2016
  • In generative design computer automatically and quickly generates many alternative design solutions, and the computer algorithms which perform the design tasks are important. The main purpose of this study is to propose a computer algorithm which generates three-dimensional shapes from a two-dimensional digital image such as a photograph or a painting. The base geometry of the final shape is a cylinder or sphere. A surface of the cylinder or sphere is deformed depending on the used image. The proposed algorithm was implemented as a computer program, and the program tested with several famous paintings. The algorithm and results presented in this study implicate the possibilities of the generative design which generates three-dimensional shapes from two-dimensional images. It is necessary to find and measure the values of the generated shape, and it will be a future research to find the relations of emotional and cognitive aspects between the input images and the generated shapes. Those studies are expected to expand the possibilities of generative design.

Study on Rapid Manufacturing of 3D Functional Parts Combining VLM-ST Process and Its RT Technology (단속형 가변적층 쾌속조형공정과 쾌속툴링 기술을 이용한 쾌속 3차원 기능성 제품 개발에 관한 연구)

  • 안동규;이상호;김기돈;양동열
    • Transactions of Materials Processing
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    • v.11 no.4
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    • pp.323-331
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    • 2002
  • The combination of rapid prototyping(RP) and rapid tooling(RT) has a potential for rapid manufacturing of three-dimensional parts. In the present study, a new RP system transfer type Variable Lamination Manufacturing using Expandable Polystyrene Foam (VLM-ST), is proposed to fabricate net shapes of three-dimensional prototypes. Various three-dimensional parts, such as a knob shape and a human head shape, are manufactured by the VLM-ST apparatus. In addition, a new rapid tooling technology, which utilizes a room temperature vulcanizing (RTV) molding technique and a triple reverse process technique, is proposed to manufacture net shapes of three-dimensional plastic parts using the prototypes of VLM-ST. A plastic part of the knob shape is produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacture of a plastic knob within two days.

Image Restoration Using OS Filters with Adaptive Windows (적응적 창을 갖는 OS 여파기를 이용한 잡음열화화상의 복원)

  • 양경호;이상길;이충웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.1
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    • pp.112-119
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    • 1990
  • Two adaptation procedures are proposed for image restoration, in which the window shapes of OS filters are changed according to the order statistics of signal. In the first procedure, the 2-dimensional window is the union of the 1-dimensional subwindows whose sizes are fixed. In the second procedure, the 2-dimensional window is the union of the 1-dimensional subwindows whose sizes are variable. Compared with existing procedures, our adaptation procedures using order statistics are computationally efficient. Simulation results show that the filters with adaptive window shapes have good performance for the preservation of edges and details of image, and the noise suppression.

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Investigation into the development of automatic VLM-$_{ST}$ process utilizing two step cutting and two reference shapes (2단계 절단과 두개의 적층 기준형상을 이용한 전자동 VLM-$_{ST}$ 공정 개발에 관한 연구)

  • 안동규;이상호;김효찬;양동열;박승교
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.62-65
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    • 2003
  • VLM-ST process requires an additional human interaction due to the manual stacking and bonding. Hence, building time, building cost and the part quality are dependent on the skill of labor. In this present work, a novel rapid prototyping (RP) process, as an automatic VLM-ST (VLM-STA), has been proposed to improve building efficiency of VLM-ST process and reliability of products. The apparatus of VLM-STA is designed to embody the process. Several characteristics of the proposed process and the apparatus are discussed. In order to examine the efficiency and the applicability of the proposed process, various three-dimensional shapes, such as a piston and a human head shape, are fabricated on the apparatus.

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Finite Difference Simulation of Two-dimensional Waves Generated by Numerical Wavemaker (수치조파기에 의해 생성되는 2차원 파도의 유한차분 시뮬레이션)

  • Lee, Young-Gill;Kim, Kang-Sin
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.10a
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    • pp.198-203
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    • 2003
  • Unsteady two-dimensional nonlinear waves which are generated by the numerical wavemaker of plunging type are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Marker-density function method is adopted for the simulation of wave breaking phenomena, and the computations are carried out with various wave amplitudes and two section shapes of wavemaker. The computation results are compared with other existing computational and experimental results, and the agreement between the experimental data and the computation results is good.

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Hydraulic Analysis Using a Two-Dimensional Model(I) : Flow Analysis around Bridge Piers with Pier Shapes (2차원 모형을 이용한 수리해석(I) : 교각형상별 주변부 흐름해석)

  • Kim, Eung-seok;Lee, Seung-hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.7
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    • pp.4936-4941
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    • 2015
  • This study(I) has analyzed hydraulic characteristics with pier shapes by the bridge construction. The pier shapes are classified into total six types such as square, rhombus, octagon, oval, round, and no-piers. One-dimensional model(HEC-RAS) and two-dimensional model (RMA-2) were employed to analyze hydraulic characteristics around bridge piers. Square and rhombus shapes of piers showed velocity vectors in the upstream direction, which has a significant impact on the river bed changes by erosion and sediment transport around the piers. The flow characteristics of the oval type pier was most similar to that of no-pier situation almost without disrupting the river flow. This analysis can help to select pier types in the new bridge construction for the future.

Nesting Problem for Two Dimensional Irregular Shapes using Heuristic (휴리스틱을 이용한 2차원 임의형상 부재 배치 문제)

  • Jeong, Sung-Kyo;Jeon, Geon-Wook
    • IE interfaces
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    • v.21 no.1
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    • pp.8-17
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    • 2008
  • A new search procedure, VLT(Vertex Line Tracing) heuristic, for two dimensional irregular shapes nesting problem was suggested in this study. The VLT heuristic was suggested to the nesting problem to overcome disadvantages of the existing NFP(No-Fit-Polygon) method. This VLT heuristic was compared with the results of the existing benchmark problems suggested by Albano, Hopper, and Burke. The results of the VLT heuristic give efficient solutions in the point of the scrap ratio and computation time. A computer program, NestLogic, using C++ for VLT heuristic was also developed for this nesting problem.

Nonsteady Plane-strain Ideal Forming without Elastic Dead-zone

  • Chung, Kwansoo;Lee, Wonoh;Kang, Tae Jin;Youn, Jae Ryoun
    • Fibers and Polymers
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    • v.3 no.3
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    • pp.120-127
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    • 2002
  • Ever since the ideal forming theory has been developed for process design purposes, application has been limited to sheet forming and, for bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was made under the plane-strain condition. In the ideal flow, material elements deform fellowing the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-strain flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, schemes to optimize preform shapes for a prescribed final part shape and also to define the evolution of shapes and frictionless boundary tractions were developed. Discussions include numerical calculations made for a real automotive part under forging.

A Study on Optimal Layout of Two-Dimensional Rectangular Shapes Using Neural Network (신경회로망을 이용한 직사각형의 최적배치에 관한 연구)

  • 한국찬;나석주
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.12
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    • pp.3063-3072
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    • 1993
  • The layout is an important and difficult problem in industrial applications like sheet metal manufacturing, garment making, circuit layout, plant layout, and land development. The module layout problem is known to be non-deterministic polynomial time complete(NP-complete). To efficiently find an optimal layout from a large number of candidate layout configuration a heuristic algorithm could be used. In recent years, a number of researchers have investigated the combinatorial optimization problems by using neural network principles such as traveling salesman problem, placement and routing in circuit design. This paper describes the application of Self-organizing Feature Maps(SOM) of the Kohonen network and Simulated Annealing Algorithm(SAA) to the layout problem of the two-dimensional rectangular shapes.