• Proceedings of the Korea Society for Simulation Conference
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• 2001.05a
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• pp.88-95
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• 2001

VR(Virtual Reality)의 개념이 제조공학 분야로 확대 적용되면서 설계분야에서의 가상조형 (Virtual Prototyping), 제조분야에서의 가상제조시스템(Virtual Manufacturing System)이라는 새로운 형태의 제조 시스템 및 설계기술이 차세대 제조기술로서 발전해 오고있으며 이런 가상제조방법(Virtual Manufacturing)은 컴퓨터를 이용하며 생산과정에서 제품뿐만이 아니라 유한요소해석을 유용하여, 공정까지도 모의실험을 하며 생산성(manufacturability), 최종 형태(final shape), 잔류 응력(residual stress), 제품 수명 주기(life-cycle)등과 같은 요소들의 최적화 정보를 제공하게 된다. 본 연구에서는 이러한 가상제조방법을 구현하기 위한 기초적 단계로서 가상단조기계를 가상현실기법을 이용하여 모델링하고 Java를 이용하여 모델링된 단조기계를 제어하고 제조되는 단조물에 대한 내부 응력 및 형태변환을 유한 요소법을 이용하여 분석하고 분석된 단조물의 자료를 WEB상을 통하여 닥 수 있게 유한 요소 해석결과를 VRML언어로 변환하는 작업을 수행하였다.

• Journal of KIBIM
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• v.7 no.4
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• pp.21-30
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• 2017

Due to the rapidly aging population, the death rate of elderly people by safety accidents has been increasing. In particular, precautions are needed for falls prevention because they either directly or indirectly cause death. In the case of elderly people, most of the fall accidents occur in dense residential areas, and particularly, the staircase poses a risk of falling. Therefore, a safety assessment should be performed from the design phase. However, in general, staircases are designed using existing stair data or only aims to satisfy the installation criteria. Laws and regulations only define minimum requirements for safety, so it is not possible to prevent fall accidents even if they satisfy the requirements. Therefore, this study proposes a simulation-based method for evaluating the safety of staircases. The behavioral characteristics of the elderly are implemented to an virtual user in a virtual space including staircases, and fall accidents are evaluated by the evaluation logic related to the behavioral characteristics. The result shows that the safety of staircases can be preevaluated and reflected on the design to reduce the possibility of fall accidents of the elderly.

• Fashion & Textile Research Journal
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• v.14 no.4
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• pp.607-613
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• 2012

This study develops a Hanbok Jeogori pattern for middle-aged women with a 3D virtual-twin and virtual-garment simulation system. The including criteria for subjects in this study was a focus on women in their 50s, and a total of 345 females satisfying them were enrolled for 3D virtual model. Comparative Jeogori pattern, Baik & Choi's(2004) pattern, was selected for the development of Jeogori pattern. The results were: first, a new Jeogori pattern considerate of middle-aged women was developed. The basic numerical formula were: Front and back bust girth B/4+1.5, armhole depth B/4, sleeve width B/4, goedae width B/10-1.5 and git width 5.5. Second, according to the results of the new Jeogori patterns appearance evaluation, the new Jeogori pattern scored higher than the existing pattern in silhouette and ease amount, this confirmed that the new Jeogori pattern is appropriate for middle-aged women. Virtual models of production through data from 3D body scan, pattern draft, and virtual garment digital program were applied to a prototypic design method to enhance the fitness of ready-made Hanbok garments. This study serves as important basic data for ensuing studies that may utilize 3D Virtual Garment Simulation System with 2D patterns and for the future 3D Pattern Production Program development of Hanbok patterns.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.128-136
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• 2014

The virtual try-on technologies of the current level have limitations with material expression as well as some difficulties with commercialization. There are differences in simulation results and subjective evaluations perceived by consumers according to the types and physical characteristics of materials used in virtual try-on simulations. This study were to analyze the exterior clothing shapes and visual images from 3D virtual try-on simulations with materials whose drapability was differentiated and then test the accuracy of the expression of the drapability of the materials. The study carried out 3D virtual try-on simulations by selecting flared skirts as an item to best express differences in drapability along with five materials of different physical properties and offered some basic data for greater utilization of virtual try-on simulations by comparing and analyzing them with the exterior shapes and visual images of actual flared skirts. The analysis results of hemline shapes between actual and virtual try-on according to the types of materials showed no match among the quantitative items of exterior shapes factors. There were no significant differences in the visual images except for "soft" according to the simulation methods, which means that the items can serve as part of a scale for visual image comparison. It is necessary to reflect quantitative numbers regarding "drapability" proposed in the study simulation software and to continue to build a systematic database for virtual simulations by investigating and testing various materials.

• The Research Journal of the Costume Culture
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• v.19 no.5
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• pp.1009-1018
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• 2011

The purpose of this study was to develop slacks patterns for middle-aged abdomen-obese adult males by using the 3D virtual-twin and virtual-garment simulation system. The criteria for subjects in this study were males who had over $25kg/m^2$ of BMI, over 90cm of waist, and over 0.90 of WHR. A total of 211 adult males who met these criteria were enrolled. The results were as follows: first, a new slacks pattern considerate of abdomen-obese men was development. The basic numerical formula were as follows: front and back hip girth H/4+3.5, front waist girth W/4+1+0.5, back waist girth W/4+1-0.5, front crotch extension H/16, back crotch extension H/8-0.5, front pleats amount 2.7, and back dart amount 1.5. Second, according to the results of the new slacks patterns appearance evaluation, the new slacks pattern scored more highly than the existing pattern in silhouette and ease amount, confirming that the new slacks pattern is appropriate for the abdomen-obese men. Also, the new slacks pattern was evaluated allowing proper space length of waist, abdomen and hip. Virtual models of production through data from a 3D body scan, pattern draft and virtual garment digital program were applied to a prototypic design method in order to enhance the fitness of ready-made garments. The use of the virtual twin made it impossible to comprehend the appearances and ease correspondent to motions. In order to evaluate wearing fitness, therefore, the system should be improved so as to change arm positions and perform various motions.

• Korean Journal of Computational Design and Engineering
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• v.16 no.5
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• pp.351-360
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• 2011

Product systems are quickly and frequently changed because Product Life Cycle is continuously reduced and adopting new product is steadily fast. Thus, various studies are progressed using simulation which is one of digital manufacturing. The research that is concerning simulation of control verification for shorten the commissioning which has a lot of trial and error is in progress. Also, simulation of control verification has strength that it can catch the errors in advance. However, a control program in simulation needs virtual factory for representation of control information. For this reason, excessive time and energy is put into controlling the virtual factory. So, in this paper, we construct library which is using exist data, in order to overcome limitation of these problems. Furthermore, we suggest methodology which can model and verify the process more speedy using library. Especially, we give body to the BB/BR Line process which has many altering equipment and need high technology effectively using physical and logical modeling. We can set up a control simulation environment very rapidly, as well as cut process time down using our suggestion.

• Journal of Drive and Control
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• v.10 no.1
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• pp.29-36
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• 2013

Excavation is an important work in mining, earth removal and general earthworks. Nowadays, automation in excavator has been studied by several researchers. In the excavator research methods, simulation is one of the low cost methods for applied to test safely. In this paper, designed a virtual hydraulic excavator that with the control and the dynamic. At first, the simulation of hydraulic system for excavator's attachment such as boom, arm and bucket using Matlab/Simhydraulic is presented. Second, the dynamic model of excavator is distributed to combine with the hydraulic system. For controlling this system, electric joysticks are used to operate the orifice open areas in Main Control Valve. The simulation result is described to analysis the performance of this virtual excavator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.6
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• pp.747-752
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• 2013

Recently, virtual test laboratory techniques have been widely used to reduce vehicle development costs and time. In this study, a virtual durability test process using multibody dynamics simulation and fatigue simulation is proposed. The flexible multibody model of the front half of a car suspension is solved using road loads that are measured from durability test courses such as a Belgian road. To verify the simulation results, the measured loads of components and simulation results are collated.

• Journal of the Korea Fashion and Costume Design Association
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• v.17 no.2
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• pp.223-237
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• 2015

This study is to compare the pattern making methods of men's jeans and to analyze sizes of parts while also evaluating the appearance and fit according to a 3D virtual garment simulation. Five types of patterns are selected for the analysis. For the appearance evaluation, the study conducted a virtual clothing simulation, created a perspective drawing, and applied Clothing pressure to each test outfit. First, according to the pattern comparisons, A and D had the shortest crotch length, while B had the longest; B had the narrowest crotch width, while C had the widest; C had the greatest waist circumference, and B had the smallest; C had the greatest knee and hem circumference, while E had the smallest. Second, according to the appearance evaluation, E pants had the highest rating overall for the waist, crotch, knee, and hem comfort; A pants had the highest rating for the yoke line end and placement; and C pants had the highest rating for the side seam line. According to the correlation analysis, ease of the waist, hips, hem and thighs were important factors (in that order) in determining the overall appearance of the jean pants.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.702-714
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• 2021

Purpose: This study aims to understand the online practice experience of nursing students through virtual simulation in order to prepare basic data for online practice program development. Methods: This study is a descriptive study that applied a qualitative thematic analysis method to explore the online practice experiences of nursing students. It was targeted to 16 students in the department of nursing at a university. Results: As a result, 5 themes such as 'Feeling ambivalent about the online practice', 'Doubts about the effectiveness of online practice', 'Running into the limits of online practice', 'Feeling like a virtual simulation as an alternative', and 'Approaching true nursing' Conclusion: Virtual simulation is considered a very effective online practice program. However, since the lack of various scenarios and cases is pointed out as a limitation, it is necessary to develop and apply more diverse and systematic practice programs in future research.