• Wind and Structures
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• v.9 no.5
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• pp.357-367
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• 2006

Unsteady 3D Reynolds Averaged Navier-Stokes (URANS) solver is used to simulate the turbulent flow past an isolated prismatic cylinder at Re=37,400. The aspect ratio of height to base width of the body is 5. The turbulence closure is achieved through a non-linear $k-{\varepsilon}$ model. The applicability of this model to predict unsteady forces associated with this flow is examined. The study shows that the present URANS solver with standard wall functions predicts all the major unsteady phenomena showing closer agreement with experiment. This investigation concludes that URANS simulations with the non-linear $k-{\varepsilon}$ model as a turbulence closure provides a promising alternative to LES with view to study flows having complex features.

• Earthquakes and Structures
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• v.18 no.2
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• pp.201-213
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• 2020

Seismic damages that occurred by the effects of epicenter distance of the earthquake are one of the most important problems for the earthquake engineering. In this study, it is aimed to examine the nonlinear seismic behaviors of concrete gravity (CG) dams considering various epicenter distances. For this purpose, Boyabat CG dam that is one of the biggest concrete gravity dams in Turkey is selected as a numerical application. FLAC3D software based on finite difference method is used for modelling and analyzing of the dam. Drucker-Prager nonlinear material model is used for the concrete body and Mohr-Coulomb nonlinear material model is taken into account for the foundation. Special interface elements are used between dam body and foundation to represent interaction condition. Free-field and quiet non-reflecting boundary conditions are utilized for the main surfaces of 3D model. Total 5 various epicenter distances of 1989 Loma Prieta earthquake are considered in 3D earthquake analyses and these distances are 5 km, 11 km, 24 km, 85 km and 93 km, respectively. According to 3D seismic results, x-y-z displacements, principal stresses and shear strain failures of the dam are evaluated in detail. It is clearly seen from this study that the nonlinear seismic behaviors of the CG dams change depending to epicenter distance of the earthquake. Thus, it is clearly recommended in this study that when a CG dam is modelled or analyzed, distance of the earthquake fault to the dam should be strongly examined in detail. Otherwise, earthquake damages can be occurred in the concrete dam body by the effects of seismic loads.

• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.11-18
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• 2011

This paper proposed a new 2-D multi-body dynamic modeling technique to analyze overriding behaviors taking place during train collision. This dynamic model is composed of nonlinear springs, dampers and masses by considering the deformable characteristics of carbodies as well as energy absorbing structures and components. By solving this dynamic model for rollingstock, energy absorbing capacities of collision elements, accelerations of passenger sections, impact forces applied to interconnecting devices, and overriding displacements can be well estimated. For a case study, we chose KHST (Korean High Speed Train), obtained crush characteristic data of each carbody section from 3-D finite element analysis, and established a 2-D multi-body dynamic model. This 2-D dynamic model was simulated under the train-to-train collision scenarios, and evaluated with 3-D virtual testing model. It was founded from the simulation results that this 2-D dynamic model could well predict overriding behaviors, and the modeling technique of carbody deformation was very important in overriding estimation.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.110-110
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• 2003

We attempted to establish the pattern remaking system using the three-dimensional data of the shape of clothes being worn, especially based on the knowledge of pattern construction. Moreover we tried to develop the deformable body model which can represent customers' body shape in the screen.

• Journal of Fashion Business
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• v.25 no.3
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• pp.71-89
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• 2021

The purpose of this study was to design posture braces for rounded shoulders by examining characteristics of incorrect postures of rounded shoulders. The review of information in literature on rounded shoulder postures, correction exercise methods, and posture correction devices, has prompted this study to determine the design and material of a proper posture brace for rounded shoulders. In order to develop the pattern of a posture brace for rounded shoulders for women, the study carried out a comfort evaluation of the braces based on the 2D patterns through drafting method by utilizing the body measurements and relational formulae associated with the major body measurement such as bust circumference and on the 3D patterns of the brace which were obtained from 3D human model of women in their early 20s in Korea. Differences in angles were noted when 2D and 3D patterns of shoulder posture braces were compared. The side neck point was relocated farther outside in the 3D pattern to allow additional flexibility in the back-neck area, and the shoulder band was lowered by 14.8°, increasing armhole area comfort. The upper hemline of the front panel was found to rotate upward at an angle of 22.0° as the underarm point of the 3D pattern moved upwards than the underarm point of the 2D pattern, which enhanced comfort in the abdomen area. The 3D designs of shoulder posture brace was preferred in this study, as they significantly improved comfort while conducting fit evaluation compared to the 2D patterns of shoulder posture brace.

• Journal of the Korean Society of Costume
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• v.63 no.8
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• pp.27-42
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• 2013

The study was aimed to develop men's working pants patterns through the computerized 3-D virtual clothing simulation system and to verify the effects of the 3-D simulated outfit by comparing it to the images of the actual outfits. The average body measurements of South Korean men aged between 30 and 39 used for the simulation in order to generate a 3-D virtual model and to realize outfits of men's working pants for the workers in the heavy industry in South Korea. And also the preliminary questionnaire survey results on certain aspects of the working pants such as type, detailed design preference and discomforting parts were taken into consideration. Both the simulated and real images of the developed working pants were compared in terms of the ease amount according to parts of the working pants, the position of seam lines, the appearance of darts and pleats, and the effects of the fabric surface according to expertise panels' subjective 5-point scale evaluation. The results throughout the study were (1) the basic working pants item worn by subject workers were the straight one pleated pants. The most discomforting parts of the working pants were in the order of body rise, thigh, hip, waist, pants hems and knee girth. (2) the drafting factors of pants patterns differed by the men's body features, which was related to the allocation of suppression amounts between waist and hip girths into darts and hip curve amounts on the waist line level of the pants. (3) the similarity of the virtually simulated and real images of men's working pants resulted in an average of 4.5 to the ease of appearance, 4.6 to the seam lines, 4.1 to the fabric surface effects in a 5-point scale, which means that the two were highly alike.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.4
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• pp.147-161
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• 2023

This study used 3D anthropometric data from the 8th Size Korea to type and analyze whole body shapes of obese women in their 20s and 30s, and constructed dimensional data for human body items needed to create a 3D human body model for each type. The data analysis used data from 148 obese women in their 20s and 30s, and a total of 48 index values, drop values, and angle items were subjected to factor analysis and one-way variance analysis to categorize body types and verify significant differences by type. As a result of the factor analysis, 12 factors were extracted and divided into 4 body types. Type 1 is a 'standard type with a curved torso with balanced upper and lower body lengths', Type 2 is a 'bending forward type with a short, thick lower body, and an uncurved torso', Type 3 is a 'lean back type with a long and thin lower body and an H-shape torso', Type 4 is a 'sway back type with a long and thick lower body and abdominal obesity'. The representative body type of obese women in their 20s and 30s was identified as Type 1. The constructed body shape information will be used as basic data for future 3D human body modeling.

• Journal of Fashion Business
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• v.24 no.4
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• pp.63-84
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• 2020

It is essential to consider the heavy industrial working environment factors which are regarded as harmful to workers' health and safety and suitable work motion factors for the workers' motion while developing the work clothes for painting workers in the machinery and shipbuilding industries. This study suggests the use of 3D virtual clothing simulations as a solution to protect the human body from hazardous working conditions accompanying the development of painting work clothes and assessing the work motion performance associated with the comfort while workers wear them during the work clothes. The initial aim of the study is to examine a male avatar to run work motions simultaneously within a 3D virtual clothing simulator, secondly, to present the simulation images of coverall type men's painting work clothes with the application of two experimental painting work motions and one control motion to the avatar, and finally, to present the distance analysis images of the painting work clothes and the avatar body and air gap rates through the analysis of cross-sections of the avatar body while wearing the coverall work clothes according to the work motions. The results showed that the distance degree of painting work clothes to the avatar body for each part of the human body when performing painting work motions. Moreover, 3D virtual clothing simulations enabled the creation of a male model avatar to run painting work motions together and the painting work clothes developed were found to be suitable for the painting work motions.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.163-181
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• 1998

In this study, the objective is determine the optimal design variable of engine mount system using the rubber mount of bush-type which is usually utilized in passive control to minimize vibrations of vehicle body or transmission from engine into body. The engine model adopted in this study is 4-cylinder, 4-stroke gasoline engine support- ed by 4-points. The system is modelled in 10 d.o.f.-rigid body motion of the engine & transmission in 6 d.o.f., elastic motion of vehicle body in 4 d.o.f.(1st torsional, 1st vertical and 1st & 2nd lateral bending vibration mode). To consider the elastic motion of vehicle body, find the eigenvalues and mode shapes of vehicle body by nodal testing and then determine the modal masses and stiffnesses of the body. The design variables of the engine mount system are locations, stiffness and damping coefficients of the rubber mounts(28 design variables). In case of considering the torque-roll axis for the engine, the design variables of the mount system are reduced to 22 design variables. The objective functions in optimal design process are considered by three cases, that is, 1) transmitted forces through engine mounts, 2) acceleration components of generalized coordinates for the vibration of vehicle body, 3) acceleration of specified location(where gear box) of body. three case are analyzed and compared with each other.

• Journal of Digital Contents Society
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• v.13 no.2
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• pp.255-262
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• 2012

Human motion tracking algorithm is receiving attention from many research areas, such as human computer interaction, video conference, surveillance analysis, and game or entertainment applications. Over the last decade, various tracking technologies for each application have been demonstrated and refined among them such of real time computer vision and image processing, advanced man-machine interface, and so on. In this paper, we introduce cost-effective and real-time human motion tracking algorithms based on depth image 3D point matching with a given superellipsoid body representation. The body representative model is made by using parametric volume modeling method based on superellipsoid and consists of 18 articulated joints. For more accurate estimation, we exploit initial inverse kinematic solution with classified body parts' information, and then, the initial pose is modified to more accurate pose by using 3D point matching algorithm.