• Title/Summary/Keyword: geometric effect

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A Visual Effect according to Pants Style and Geometric Pattern - Using a 3D Virtual Garment System - (가상착의 시스템을 이용한 팬츠 스타일과 기하학 무늬의 특성에 따른 시각적 효과)

  • Park, Woo Mee
    • Fashion & Textile Research Journal
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    • v.15 no.4
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    • pp.504-513
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    • 2013
  • This study evaluates the difference of visual effect according to pant style and geometric pattern. The researcher made 28 stimuli-combination of four pant Stiles (classic, baggy, skinny, and bell-bottom) and seven geometric pattern (large vertical stripe, small vertical stripe, large horizontal stripe, small horizontal stripe, large check, small check, and hound's tooth check). The test involved 96 female college students. The stimuli were made with the i-Designer computer program. The panels tested the computer screen images of all manikins wearing pants. A 7-point scale was used to evaluate each image. For the data analysis, ANOVA and Duncan-test were applied along with an SPSS program. The results of this study are as follows. Three factors (lower-body compensation, abdomen highlight, and length compensation) influenced the visual effect pant styles and geometric patterns. The skinny style and large vertical stripe evaluated positively in elongated height and leg length and a slimmer overall body. It was shown that the vertical stripe pattern was evaluated as more positive than the horizontal stripe pattern in the visual effect; particularly, the results showed distinct aspects in the classic pants style. The mutual influence of the visual effect (according to pants style and geometric pattern) were indicated as two factors of lower-body compensation and length compensation. A more positive visual effects resulted in a higher mutual influence on pant style and geometric pattern.

Numerical modelling of nonlinear behaviour of prestressed concrete continuous beams

  • Lou, Tiejiong;Lopes, Sergio M.R.;Lopes, Adelino V.
    • Computers and Concrete
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    • v.15 no.3
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    • pp.373-389
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    • 2015
  • The development of a finite element model for the geometric and material nonlinear analysis of bonded prestressed concrete continuous beams is presented. The nonlinear geometric effect is introduced by the coupling of axial and flexural fields. A layered approach is applied so as to consider different material properties across the depth of a cross section. The proposed method of analysis is formulated based on the Euler-Bernoulli beam theory. According to the total Lagrangian description, the constructed stiffness matrix consists of three components, namely, the material stiffness matrix reflecting the nonlinear material effect, the geometric stiffness matrix reflecting the nonlinear geometric effect and the large displacement stiffness matrix reflecting the large displacement effect. The analysis is capable of predicting the nonlinear behaviour of bonded prestressed concrete continuous beams over the entire loading stage up to failure. Some numerical examples are presented to demonstrate the validity and applicability of the proposed model.

Effect of Geometric Shapes on Stability of Steel Cable-stayed Bridges (기하형상에 따른 강사장교의 안정성에 관한 연구)

  • Kim, Seung-Jun;Han, Seung-Ryong;Kim, Jong-Min;Cho, Sun-Kyu;Kang, Young-Jong
    • Journal of Korean Society of Steel Construction
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    • v.23 no.1
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    • pp.13-27
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    • 2011
  • This paper presents an investigation of the structural stability of cable-stayed bridges, using geometric nonlinear finite-element analysis and considering various geometric nonlinearities, such as the sag effect of the cables, the beam-column effect of the girder and mast, and the large displacement effect. In this analytic research, a nonlinear frame element and a nonlinear equivalent truss element were used to model the girder, mast, and cable member. The live-load cases that were considered in this research were assumed based on the traffic loads. To perform reasonable analytic research, initial shape analyses in the dead-load case were performed before live-load analysis. In this study, the geometric nonlinear responses of the cable-stayed bridges with different cable arrangement types were compared. After that, parametric studies on the characteristics of the structural stability in critical live-load cases were performed considering various geometric parameters, such as the cable arrangement type, the stiffness ratios of the girder and mast, the area of the cables, and the number of cables. Through this parametric study, the effect of geometric shapes on the structural stability of cable-stayed bridges was investigated.

Effects of Geometric Errors on the Measurement of Error Motions of Rotor with the Cylindrical Capacitive Displacement Sensor (형상오차가 원통형 정전용량 변위센서의 축 회전오차의 측정에 미치는 영향)

  • 안형준;장인배;한동철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.487-490
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    • 1995
  • This paper discisses the effects geometric errors on the measurement of error motions of rotor with the cylindrical capacitive displacement sensor. Analytic model of the measuring process with this sensor is derived and this model shows that the effect of geometric errors of sensor is larger than that of rator on the measurement of error motions of rotor. The computer simulation shows effect of periodic errors in this sensor on the measuring orbit.

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Nonlinear control of a double-effect evaporator by riemannian geometric approach

  • Izawa, Yoshiaki;Hakomori, Kyojiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1994.10a
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    • pp.405-410
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    • 1994
  • The purpose of this paper is to present the details of design procedure of a nonlinear regulator by Riemannian geometric approach and to applied it to the case of a double-effect evaporator. A nonlinear geometric model is proposed on a direct sum space of a state vector and a control vector as well as in the previous parers by the authors. The geometric model is derived by replacing the orthogonal straight coordinate axes of a linear system on the direct sum space with the curvilinear coordinate axes. The integral manifold of the geometric model becomes homeomorphic to that of fictitious linear system. For the geometric model a nonlinear regulator with a performance index is designed renewedly by the procedure of optimization. The construction method of the curvilinear coordinate axes on which the nonlinear system behaves as a linear system is discussed. To apply the above regulator theory to double-effect evaporators especially to the pilot plant at the University of Alberta, a suitable nonlinear model is determined by the plant dynamics. The optimal control law is derived through the calculation of the homeomorphism. As a result it is confirmed that the regulator is effective and superior to that of the conventional control.

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A Study on Marginal Effect of Geometric Structure on Freeway Accident Frequencies (고속도로 교통사고에 대한 기하구조의 영향(한계효과)에 관한 연구)

  • Park, Min Ho
    • Journal of Korean Society of Transportation
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    • v.32 no.1
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    • pp.73-81
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    • 2014
  • This study dealt with the impacts of geometric structure on traffic accidents occurring on the interstates. There are standard values for the case of geometric structure which are recommended in the design guideline/policy; however, in the previous models, geometric variables were adapted as integrated ones as opposed to mixed ones in the real world so that derived models had a weakness to reflect the real. Therefore, using subdivided geometric variables, this study tried to derive the model which reflects the real world. In addition, by calculating elasticity, each variables' effect to the accidents are estimated. Hopefully, this study will help to establish the future guideline/policy of geometrics considering traffic safety.

Geometric and Wave Optic Features in the Optical Transmission Patterns of Injection-molded Mesoscale Pyramid Prism Patterned Plates

  • Lee, Je-Ryung;Je, Tae-Jin;Woo, Sangwon;Yoo, Yeong-Eun;Jeong, Jun-Ho;Jeon, Eun-chae;Kim, Hwi
    • Current Optics and Photonics
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    • v.2 no.2
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    • pp.140-146
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    • 2018
  • In this paper, mesoscale optical surface structures are found to possess both geometric and wave optics features. The study reveals that geometric optic analysis cannot correctly predict the experimental results of light transmission or reflection by mesoscale optical structures, and that, for reliable analyses, a hybrid approach incorporating both geometric and wave optic theories should be employed. By analyzing the transmission patterns generated by the mesoscale periodic pyramid prism plates, we show that the wave optic feature is mainly ascribed to the edge diffraction effect and we estimate the relative contributions of the wave optic diffraction effect and the geometric refraction effect to the total scattering field distribution with respect to the relative dimension of the structures.

Analytical Study of Geometric Nonlinear Behavior of Cable-stayed Bridges (사장교의 기하학적 비선형 거동의 해석적 연구)

  • Kim, Seungjun;Lee, Kee Sei;Kim, Kyung Sik;Kang, Young Jong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1A
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    • pp.1-13
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    • 2010
  • This paper presents an investigation on the geometric nonlinear behavior of cable-stayed bridges using geometric nonlinear finite element analysis method. The girder and mast in cable-stayed bridges show the combined axial load and bending moment interaction due to horizontal and vertical forces of inclined cable. So these members are considered as beam-column member. In this study, the nonlinear finite element analysis method is used to resolve the geometric nonlinear behavior of cable-stayed bridges in consideration of beam-column effect, large displacement effect (known as P-${\delta}$ effect) and cable sag effect. To analyze a cable-stayed bridge model, nonlinear 6-degree of freedom frame element and nonlinear 3-degree of freedom equivalent truss element is used. To resolve the geometric nonlinear behavior for various live load cases, the initial shape analysis is performed for considering dead load before live load analysis. Then the geometric nonlinear analysis for each live load case is performed. The deformed shapes of each model, load-displacement curves of each point and load-tensile force curves for each cable are presented for quantitative study of geometric nonlinear behavior of cable-stayed bridges.

Effect of Change of Grinding Force on Geometric Error (연삭력 변화량이 공작물의 형상오차에 미치는 영향)

  • Chi, Long-Zhn;Lee, Sang-Jin;Park, Hoo-Myung;Oh, Sang-Lok;Ha, Man-Kyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.3 no.2
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    • pp.10-17
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    • 2004
  • A real depth of cut in deformed zone has larger than an ideal depth of cut. So the heat generated during grinding operation makes the deformation of a workpiece surface as convex farm. Consequently the workpiece surface remains a geometric error as concave form after cooling In this study, the grinding force and the geometric error were examined in surface grinding. Through magnitude and mode of geometric error were evaluated according to grinding conditions, an optimal grinding condition was proposed to minimize the geometric error In addition, the relationship between the geometric error and the grinding force was examined. Due to least square regression, It was possible to predict the geometric error by using the grinding force.

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Influence of Geometric Initial Imperfection on the First Buckling Time Variation of Cylinder Under Impact Load (충격하중을 받는 원통의 최초좌굴시간의 변동성에 대한 기하학적 초기결함의 영향)

  • 김두기
    • Computational Structural Engineering
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    • v.10 no.1
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    • pp.173-183
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    • 1997
  • In this paper a method is suggested for the probabilistic analysis of impact buckling failure time of cylinder with random axisymmetric geometric imperfection under axial impact. Failure is assumed as axisymmetric radial deformation exceeds the given criteria for the first time. For the generation of random geometric initial imperfection, random field theory by mean function and autocorrelation function of geometric imperfection is used. Suggested method is useful for the treatment of the randomness of realistic geometric imperfection and can be used for the structural safety analysis of cylinder considering its effect.

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