• Title/Summary/Keyword: 3D shape analysis

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3D Tunnel Shape Fitting by Means of Laser Scanned Point Cloud (레이저 스캐닝 측점군에 의한 터널 3차원 형상의 재현)

  • Kwon, Kee Wook;Lee, Jong Dal
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.4D
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    • pp.555-561
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    • 2009
  • In lieu of section profile data, a fitting of the bored tunnel shape is more significant confirmation for maintenance of a tunnel. Before the permit on the completion of a tunnel, deformation of the completed tunnel with respect to the design model are considered. And deformation can be produced at continuously along the entire of the tunnel section. This study firstly includes an analysis of algebraic approach and test it with an observed field data. And then a number of methods, line search method, genetic algorithm, and pattern search methods, are compared with the 3D tunnel shape fitting. Algebraic methods can solve a simple circular cylinder type as like a railway tunnel. However, a more complex model (compound circular curve and non circular) as like a highway tunnel has to be solved with soft computing tools in the cause of conditional constraints. The genetic algorithm and pattern search methods are computationally more intensive, but they are more flexible at a complex condition. The line search method is fastest, but it needs a narrow bounds of the initial values.

3D Face Alignment and Normalization Based on Feature Detection Using Active Shape Models : Quantitative Analysis on Aligning Process (ASMs을 이용한 특징점 추출에 기반한 3D 얼굴데이터의 정렬 및 정규화 : 정렬 과정에 대한 정량적 분석)

  • Shin, Dong-Won;Park, Sang-Jun;Ko, Jae-Pil
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.6
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    • pp.403-411
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    • 2008
  • The alignment of facial images is crucial for 2D face recognition. This is the same to facial meshes for 3D face recognition. Most of the 3D face recognition methods refer to 3D alignment but do not describe their approaches in details. In this paper, we focus on describing an automatic 3D alignment in viewpoint of quantitative analysis. This paper presents a framework of 3D face alignment and normalization based on feature points obtained by Active Shape Models (ASMs). The positions of eyes and mouth can give possibility of aligning the 3D face exactly in three-dimension space. The rotational transform on each axis is defined with respect to the reference position. In aligning process, the rotational transform converts an input 3D faces with large pose variations to the reference frontal view. The part of face is flopped from the aligned face using the sphere region centered at the nose tip of 3D face. The cropped face is shifted and brought into the frame with specified size for normalizing. Subsequently, the interpolation is carried to the face for sampling at equal interval and filling holes. The color interpolation is also carried at the same interval. The outputs are normalized 2D and 3D face which can be used for face recognition. Finally, we carry two sets of experiments to measure aligning errors and evaluate the performance of suggested process.

Numerical simulation of the influence of interaction between Qanat and tunnel on the ground settlement

  • Sarfarazi, Vahab;Tabaroei, Abdollah
    • Geomechanics and Engineering
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    • v.23 no.5
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    • pp.455-466
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    • 2020
  • This paper presents analysis of the interaction between tunnel and Qanat with a particular interest for the optimization of Qanat shape using the discrete element code, PFC2D, and the results will be compared with the FEM results of PLAXIS2D. For these concerns, using software PFC2D based on Discrete Element Method (DEM), a model with dimension of 100m 100 m was prepared. A circular tunnel with dimension of 9 m was situated 20 m below the ground surface. Also one Qanat was situated perpendicularly above the tunnel roof. Distance between Qanat center and ground surface was 8 m. Five different shapes for Qanat were selected i.e., square, semi-circular, vertical ellipse, circular and horizontal ellipse. Confining pressure of 5 MPa was applied to the model. The vertical displacement of balls situated in ground surface was picked up to measure the ground subsidence. Also two measuring circles were situated at the tunnel roof and at the Qanat roof to check the vertical displacements. The properties of the alluvial soil of Tehran city are: γdry=19 (KN/㎥), E= 750 (kg/㎠), ν=0.35, c=0.3(kg/㎠), φ=34°. In order to validate the DEM results, a comparison between the numerical results (obtained in this study) and analytical and field monitoring have been done. The PFC2D results are compared with the FEM results. The results shows that when Qanat has rectangular shape, the tensile stress concentration at the Qanat corners has maximum value while it has minimum value for vertical ellipse shape. The ground subsidence for Qanat rectangular shape has maximum value while it has minimum value for ellipse shape of Qanat. The vertical displacements at the tunnel roof for Qanat rectangular shape has maximum value while it has minimum value for ellipse shape of Qanat. Historical shape of Qante approved the finding of this research.

EMG Analysis for Investigation Muscle-Collaborated Relationship during Golf Swing (골프스윙시 근육협응관계 구명을 위한 EMG 분석)

  • Shim, Tae-Yong;Shin, Seong-Hyu;Oh, Seung-Il;Mun, Jung-Hwan
    • Korean Journal of Applied Biomechanics
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    • v.14 no.3
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    • pp.177-189
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    • 2004
  • Kinematic and kinetic analysis using 3D Motion Capture system are common, yet there is little in the literature that discuss the relationship and coactivity between muscles during the golf swing. The purpose of this study was to describe the relationship between the employed 16 muscles during golf swing. We could observe 3 muscle patterns such as 'Line' shape, 'L' shape, and 'Loop' shape for the golf swing activity. The 'Line' shape indicates that two muscles act almost perfectly in phase, and the 'L' shape represents that two muscles act in a reciprocating manner(When one is active, the other is quiescent and vice versa). And the 'Loop' shape indicates that two muscles act sequently(After one is active, the other act). In these results, we knew the muscle patterns during golf swing is similar to the patterns during gait. And we presented it was possible to show the consistence of golf swing through the frequency analysis of muscle patterns. We believe that the results potentially useful for the golf players and coaches to analyze their performance.

Developing of Grading Method using 3D Body Measurement Data of Women in Their Thirties -Focusing on Their Proper Body Types-

  • Shin, Ju-young Annie;Nam, Yun-ja
    • Fashion & Textile Research Journal
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    • v.19 no.6
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    • pp.749-758
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    • 2017
  • The purpose of the present study is to develop a grading deviation, which is appropriate for the body type of women in thirties, by analyzing the three-dimensional body type. The materials for the study were adopted from the body measurement data of women in the age group of 30 to 39 years old, provided from Size Korea. By reflecting the factor analysis results using the three-dimensional shape measurement, deviations were derived. First, six factors influencing the changes in human body shape were derived as waist-hip length factor, bust-waist shape factor, back protrusion back shoulder factor, bust length factor, shoulder length factor, and frontal waist dart factor. The bust size and height, which can be easily utilized for the top original grading, were used for deriving a regression formula, and the deviation was set in accordance with the result. Second, by applying the deviation which reflects the changes in the body shape, the crimps which were generated due to the application of existing deviation were remarkably reduced, indicating that the grading of the present study is more fitting than the existing one. The deviation derived by the analysis of actual increase and decrease of body size was more fitting than the existing one. This was proved by actual wearing experiment, which represents the significance of this study.

Numerical Study on Variation of Penetration Performance into Concrete by Penetrator Nose Shape (침투자의 노즈 형상에 따른 콘크리트 침투성능 변화에 관한 수치적 연구)

  • Ju, Yongwon
    • Journal of the Korea Society for Simulation
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    • v.27 no.3
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    • pp.109-116
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    • 2018
  • In order to destroy the hard target, it is essential to develop a penetration warhead with high penetration performance. To design a penetration warhead, this paper discusses the effect of nose shape factors such that nose shape, nose length, nose tip diameter, on the penetration performance of the penetrator. AUTODYN-2D has been used to conduct the computational analysis. The experimental result of Forrestal, and a simulation result have been compared to verify the reliability of computational analysis. Computational results show that the nose length have more influence on the penetration performance than the nose shape. Furthermore, simulation results show that the penetration performance can be improved by increasing the nose tip diameter to a specific value, when the nose length of the penetrator is uniform.

Comparative Analysis of Body Measurement and Fit Evaluation between 2D Direct Body Measuring and 3D Body Scan Measuring (직접측정과 3차원 측정에 따른 인체치수 및 의복 착장 비교분석)

  • Istook, Cynthia L.;Lim, Ho-Sun;Chun, Jong-Suk
    • The Research Journal of the Costume Culture
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    • v.19 no.6
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    • pp.1347-1358
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    • 2011
  • This study purposed to analyze differences in body measurement between the 2D direct body measuring method and the 3D body scan measuring method and to perform the appearance evaluation and cross-sectional evaluation of the fit of pants to which body measurements obtained by each measuring method were applied. Body measuring was conducted in 10 women in their 20s-30s using 2D direct body measuring and 3D automatic measuring with Hamamatsu body scanner. Among the 10 women, 3 participated in experimental garment wearing. Experimental pants were made using their 2D direct body measurements and 3D automatic measurements, and wearing tests were performed through expert evaluation and cross-sectional evaluation. The results of the experiment were as follows. According to the results of comparative analysis on differences between 2D direct body measurements and 3D scan measurements, 3D automatic measurements were significantly larger in bust circumference, ankle circumference, armscye circumference, shoulder length, scye depth, and arm length. As circumferences measured with the 3D body scanner were somewhat larger than directly measured ones, it is suggested to adjust ease when using existing pattern making methods. We prepared experimental garments by the same pattern making method through applying body measurements obtained with the two measuring methods, and assessed the fit of the garment comparatively through expert evaluation and 3D scan cross-sectional evaluation. According to the results, 2D-pants using 2D direct body measurements was slightly tighter than 3D-pants using 3D measurements in waist circumference, hip circumference, and abdominal circumference. In the results of comparing appearance in terms of the fit of the experimental garment in each subject, significant difference was observed in most of the compared items. This result suggests that 3D automatic body measuring data may show different accuracy according to body shape and therefore it is necessary to examine difference between 2D direct body measurements and 3D automatic measurements according to body shape.

Development of a Structural Shape Optimization Scheme Using Selective Element Method (선택적 요소방법을 이용한 구조 형상최적 설계기법의 개발)

  • 심진욱;박경진
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.12
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    • pp.2101-2109
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    • 2003
  • Structural shape optimization offers engineers with numerous advantages in designing shapes of structures. However, excessive relocation of nodes often cause distortion of elements and eventually result in degrade of accuracy and even halts of processes. To overcome these problems, an effective method, Selective Element Method(SEM), has been developed. This paper describes the basic concept of SEM and processes to implement into real-world problem. 2-D and 3-D shape optimization problems have been chosen to show the performance of the method. Though some limitations have been found, it was concluded that SEM can be useful in general shape optimization and even in some special cases such as decision of optimal weld line location.

Guidelines for Virtual Clothes Modeling and Draping Software - Based on the Analysis of Maya Cloth - (가상의상 모델링 및 착장 소프트웨어를 위한 가이드라인)

  • Kim, Sook-Jin
    • Journal of the Korean Home Economics Association
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    • v.44 no.2 s.216
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    • pp.127-135
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    • 2006
  • This paper suggests guidelines for virtual clothes modeling and draping software suitable for clothes designers. We first analyze Maya Cloth, which is widely used in game and animation fields, and which has been adopted by Pad System as a 3D cloth draping system. We then discuss what functions and procedures would improve Maya Cloth to assist designers in being able to create the clothes they have conceptualized. While Maya Cloth has many good functions and features forvirtual cloth modeling and draping, it treats input 2D patterns as approximat and it creates 3D clothes by considering other factors such as the 3D body model. As a result, it is hard for clothes designers to control the shape of the 3D clothes by changing 2D patterns. Furthermore, Maya Cloth does not handle seamlines satisfactorily. We suggest that the following new features should be added to Maya Cloth : respecting the input 2D patterns, handling seamlines, and controlling the shape of the clothes in 3D space.

The Relevances of the Ease and the Appearance by Changing the Sleeve Cap Height Using Virtual Garment System (가상봉제에 의한 소매산 높이의 변화가 봉합여유량 및 외관에 미치는 영향)

  • Han, Mi-Ran;Kim, Yeo-Sook
    • The Korean Journal of Community Living Science
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    • v.23 no.2
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    • pp.189-198
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    • 2012
  • This study aim was to understand the effects of the change of the sleeve cap height on the sleeve cap line and the sleeve appearance by making nine different sleeve cap height patterns. When a subject sews the virtual and real garments with this, it provides data base through which she can make the suitable sleeve by conducting a comparative analysis of the appearance and cross-sectional diagram and grasping the relation between the sleeve cap line ease and the shape of the sleeve. As a result of the analysis of the image of 3D virtual garment, the shape of the armscye and the position of the bust line and sleeve baseline, the sleeve cap height and the sewing ease of the sleeve cap line affect on the shape of the sleeve and the armscye. Although the real garment is slightly different from the virtual garment they have shown similar tendency. Therefore, if the 3D virtual clothing system is used appropriately, it is possible to expect various study results in the apparel field without making real garments.