• Title/Summary/Keyword: SHAPE

Search Result 32,937, Processing Time 0.057 seconds

Effect of Capsule Shape on Heat Storage (캡슐 형상이 축열에 미치는 영향)

  • 정재동
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.14 no.11
    • /
    • pp.964-971
    • /
    • 2002
  • A numerical investigation of the constrained melting of phase change materials within spherical-like capsule is presented. A single-domain enthalpy formulation is used for simulation of the phase change phenomenon. The solution methodology is verified with the melting process inside an isothermal spherical capsule. Especially, the effect of capsule shape on the heat storage is emphasized. Two shape parameters are considered from the real capsule shape showing good characteristics of heat storage and the effect of these parameters is examined. Early during the melting process, the conduction mode of heat transfer is dominant. Thus the capsule shape with large surface area is desirable. However, the capsule shape with large surface area plays negative role on the strength of buoyancy-driven convection that becomes more important as melting continues.

A Shape Finding and Cutting Pattern Determination for Membrane Structures (막 구조물에 관한 형상 탐색과 재단도 결정법)

  • Choi, Ho;Lee, Jang-Bog;Kim, Jae-Yeol;Sur, Sam-Uel;Kwon, Taek-Jin
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 1998.04a
    • /
    • pp.175-182
    • /
    • 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, (1) shape finding analysis formulation and an example, (2) cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

  • PDF

A Study on Women′s Face Types Classification by Visual Distinction and Difference from the Measurement (시각적 판단에 의한 얼굴유형 분류와 계측 특성 연구)

  • Namwon Moon
    • The Research Journal of the Costume Culture
    • /
    • v.8 no.1
    • /
    • pp.133-144
    • /
    • 2000
  • The purpose of this study was to classify women's face types by visual distinction and to analyze the measurement of face types. A survey was conducted by subjects of 167 women's college students in Kwangju City and Chonnam area. Data were analyzed by Frequencies, Mean, one way ANOVA and Ducan's Multiple Range Test. The major results were as followed ; ·Women's face types were classified by 7 types and there were oblong shape(28.3%), egg shape(25.7%), round shape(23.9%), square shape(12.4%), inverted triangle shape(5.3%), diamond shape(3.5%), triangle shape(0.8%) in the subjects. ·From the measurements of the women's face, index of face length to face breadth was 1.38, it means that the index was different from the other refferences. And the lower face length was longer than the upper and the middle face lengths. ·Differences From those measurements like forehead breadth, face length/bizigion breath(p〈.001), bizigion breadth, bignathion slopper, stature(p〈.01) and trichion breadth, tragion-menton length(p〈.05) were significant in the classified face types.

  • PDF

Method of Shape Error Measurement for the Optimal Blank Design of Shapes with 3D Contour Lines (목표윤곽선이 3 차원 곡선인 형상의 최적블랭크 설계를 위한 형상오차 측정법)

  • Shim, H.B.
    • Transactions of Materials Processing
    • /
    • v.24 no.1
    • /
    • pp.28-36
    • /
    • 2015
  • After a short review of the iterative optimal blank method, a new method of measuring the shape error for stamped parts with 3D contour lines, which is an essential component of the optimal blank design, is proposed. When the contour line of the target shape does not exist in a plane, but exists in 3D space, especially when the shape of the target contour line is very complicated as in the real automotive parts, then the measurement of the shape error is critical. In the current study, a method of shape error measurement based on the minimum distance is suggested as an evolution of the radius vector method. With the proposed method, the optimal blank shapes of real automotive parts were found and compared to the results of the radius vector method. From the current investigation the new method is found to resolve the issues with the radius vector method.

Effect of lubrication on the evolution of strain states in AA 5052 sheet during shape rolling (알루미늄 5052 합금 판재의 이형 압연 시 변형률 상태에 미치는 윤활의 영향)

  • Park, E.S.;Hwang, K.C.;Huh, M.Y.;Kim, H.J.;Bae, J.C.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.05a
    • /
    • pp.256-259
    • /
    • 2009
  • In order to investigate the effect of strain states attributed to the lubrication during shape rolling, shape rolling for V-sectioned sheets was carried out with and without lubrication. The evolution of strain states during shape rolling was studied by three-dimensional finite element method (FEM). Shape rolling with and without lubrication produces shape-rolled samples in fairly similar outer shapes, since the distribution of normal strain components is nearly independent of the lubrication condition. In contrast, the distribution of shear strain components strongly depends on the lubrication condition.

  • PDF

Shape recovering trials from dried waterlogged wood (건조 수침고목재의 원형회복 실험)

  • Cho, Kyu-A;Park, Sang-Jin
    • 한국문화재보존과학회:학술대회논문집
    • /
    • 2004.10a
    • /
    • pp.66-71
    • /
    • 2004
  • When waterlogged wood dries up, it shrinks largely. And it is hard to recover original shape. Therefore it happens to lose the value of wood remains frequently. This paper studied how far dried waterlogged wood can recover original shape. Shape recovering course and extent are thoroughly investigated after waterlogged wood of Pinus densiflora, Quercus serrata and Styrax japonica oven-dries and instills varieties of test solution. At 1- step, oven-dried samples infiltrated by chlorous acid sodium or sodium hydroxide solution. At 2- step, wood tissues of samples were swelled by the fast decompression after infiltrating $CO_2-supercritical$ fluid at high pressure. The study investigated the possibility of shape recovering in waterlogged wood. Shape recovering rate is different with solution and wood species. Sample of sodium hydroxide solution doesn't swell anymore when using $CO_2-supercritical$ fluid. In general, the sample of sodium hydroxide solution has higher Shape recovering rate than $CO_2-supercritical$ fluid solution treated by chlorous acid sodium.

  • PDF

Shape Recognition and Classification Based on Poisson Equation- Fourier-Mellin Moment Descriptor

  • Zou, Jian-Cheng;Ke, Nan-Nan;Lu, Yan
    • International Journal of CAD/CAM
    • /
    • v.8 no.1
    • /
    • pp.69-72
    • /
    • 2009
  • In this paper, we present a new shape descriptor, which is named Poisson equation-Fourier-Mellin moment Descriptor. We solve the Poisson equation in the shape area, and use the solution to get feature function, which are then integrated using Fourier-Mellin moment to represent the shape. This method develops the Poisson equation-geometric moment Descriptor proposed by Lena Gorelick, and keeps both advantages of Poisson equation-geometric moment and Fourier-Mellin moment. It is proved better than Poisson equation-geometric moment Descriptor in shape recognition and classification experiments.

The Reliability and Validity of the Korean version of the Body Shape Questionnaire

  • Kim, Tae-Sung;Chee, Ik-Seung
    • Anxiety and mood
    • /
    • v.14 no.1
    • /
    • pp.36-43
    • /
    • 2018
  • Objective : There is an increasing number of people are not satisfied with their appearance and shape. Therefore, assessment tools are needed to evaluate the appearance or body shape. This study investigated the reliability and validity of a Korean version of the Body Shape Questionnaire (BSQ). Methods : Participants completed the BSQ, Body Dysmorphic Disorder Examination-Self Report, Eating Disorder Inventory-2, Beck Depression Inventory, Self-Esteem Scale, State-Trait Anger Expression Inventory, and State-Trait Anxiety Inventory. Results : The Korean version of BSQ presented satisfactory test-retest reliability, internal consistency and validity. Exploratory factor analysis yielded four factors as follow: feeling fat, shame and inferiority about one's body shape, attitudes concerning body image perception, and purging behavior. Conclusion : These results show the Korean BSQ exhibits good psychometric properties and can accurately evaluate the body shape concerns among Korean adults.

Workpiece-Chucking Device Using Two-Way Shape Memory Alloys: Feasibility Test (양방향성 형상기억합금을 이용한 공작물 척킹장치: 유용성 검증)

  • Shin, Woo-Cheol;Ro, Seung-Kook;Park, Jong-Kweon
    • Journal of the Korean Society of Manufacturing Technology Engineers
    • /
    • v.18 no.5
    • /
    • pp.462-468
    • /
    • 2009
  • In this study, a workpiece-chucking device that generates a chucking force from a shape memory alloy is introduced. This paper first presents train procedure to transform a commercial one-way shape memory alloy into a two-way shape memory alloy, which makes unclamping mechanism of the chucking device simpler than that using the one-way shape memory alloy Second, it describes a conceptual design of the workpiece-chucking device using the two-way type shape memory alloy. Third, it presents a prototype and its chucking characteristics, such as time-response of clamping/unclamping operations and a relationship between temperatures and chucking forces. Finally, it describes a mill-machining test conducted with the prototype. The results confirm that the proposed workpiece-chucking device is feasible for micro machine-tools.

  • PDF

An Estimate for Convergence and Efficiency of Nonlinear Shape Analysis According to the Control Techniques (제어기법에 따른 비선형 형상해석의 수렴성 및 효율성 펑가)

  • Jeong, Eul-Seok;Jeon, Jin-Hyung;Shon, Su-Deog;Kim, Seung-Deog
    • Proceeding of KASS Symposium
    • /
    • 2006.05a
    • /
    • pp.214-223
    • /
    • 2006
  • Membrane structures, a kind of lightweight soft structural system, are used for spatial structures. The material property of the membrane has strong axial stiffness, but little bending stiffness. The design procedure of membrane structures are needed to do shape finding, stress-deformation analysis and cutting pattern generation. In shape finding, membrane structures are unstable structures initially. These soft structures need to be introduced initial stresses because of its initial unstable state, and happen large deformation phenomenon. Therefore, in this study, to find the structural shape after large deformation caused by initial stress, we need the shape analysis considering geometric nonlinear term. And we investigate the evaluation of shape analysis technique's convergence and efficiency according to the control method

  • PDF