• 소성∙가공
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• 제12권2호
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• pp.110-115
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• 2003

This paper is concerned with the compression test and forming process of flange by using virtual reality and analysis(simulation) program. This virtual manufacturing can be carried out one personal computer without any expensive devices for experiment. The virtual manufacturing composed of three modules such as the imput, calculation and the output modules on internet. Internet user can give the material's property and process parameters to the sever computer at the input module. On the calculation module, a simulator computes the virtual manufacturing process by analysis program and stores the data as a file. The output module is the program in which internet user can confirm virtual manufacturing results by showing tables, graphs, and 3D animation. This programs is designed by an internet language such as HTML, CGI, VRML and JAVA ,while analysis programs use the finite increasing, the virtual manufacturing technique will substitute many real experiments in the future.

• 비파괴검사학회지
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• 제23권3호
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• pp.189-197
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• 2003

Nucleation of a crack is readily defected by acoustic emission (AE) method. One powerful technique for AE waveform analysis has been developed as SiGMh (Simplified Greens functions for Moment tensor Analysis), as crack kinematics of locations, types and orientations are quantitatively determined. Because these kinematical outcomes are obtained as three-dimensional (3-D) locations and vectors, 3-D visualization is definitely desirable. To this end, the visualization system has been developed by using VRML (Virtual Reality Modeling Language). As an application, failure protest of a reinforced concrete beam is discussed.

• 한국컴퓨터정보학회논문지
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• 제24권9호
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• pp.69-75
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• 2019

We propose a method to analyze user requirements to design a virtual reality-based risk management system. This paper presents surveys, interviews, prototype evaluation methods, and implementation process. Architectural heritage is easily exposed to natural and artificial dangers caused by various material combinations and structural features. So, risk management of cultural heritage plays a key role in preserving and managing cultural heritage. However, risk management has been carried out through empirical methods using distributed data. This study analyzes user requirements for designing functions and interfaces of VR-based risk management system and evaluates prototypes to overcome the above problems. As a result, most heritage managers wanted a system function to support risk analysis and response. They also found that they prefer 2D information such as existing drawings and photos rather than 3D information. The results of the user requirements analysis derived from this study will be used to create risk management applications.

• 디지털융복합연구
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• 제17권5호
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• pp.235-247
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• 2019

본 연구는 뇌졸중 환자의 기능회복에 대한 가상현실 운동프로그램의 효과를 검증하기 위해 수행된 체계적 문헌고찰 및 메타분석 연구이다. 데이터베이스는 학술연구정보서비스(RISS), 한국학술정보(Korean studies Information Service System, KISS), 한국 의학논문데이터베이스(KMbase)를 활용하여 '뇌졸중', '뇌경색', '상지기능', '균형', '일상생활능력', '운동훈련', '운동중재' '재활' '가상현실', '가상현실 교육', '가상현실 프로그램'을 검색어로 최근 10년(2009년~2018년)간 문헌을 검토하였다. 분석은 R을 이용한 임의효과모형을 적용하여 상지기능, 균형과 일상생활능력의 효과 크기를 각각 산출하였다. 최종적으로는 RCT 9편을 분석하였다. 개별문헌은 Cochrane Collaboration의 RoB (Risk of Bias) 도구를 통해 비뚤림 위험을 평가하였으며, 전반적인 비뚤림 위험은 낮았다. 본 연구결과 균형에 대한 효과크기(g=.77), 일상생활 활동에 대한 효과크기(g=.80)로 "큰 효과크기"를 나타내었다. 따라서, 뇌졸중 환자의 균형과 일상생활능력 향상을 위한 가상현실 운동프로그램이 효과적임을 확인하게 되었다. 향후 가상현실 운동프로그램 이용한 보다 효과적인 프로그램 개발과 적용에 대한 연구가 필요하다고 생각된다.

• 대한물리치료과학회지
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• 제28권3호
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• pp.11-29
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• 2021

Background: The purpose of this study is to investigate the effects of virtual reality on gait, balance, and upper extremity functions compared to other independent variables or no variables. Additionally, the possibility of virtual reality for stroke patients was discussed. Design: Meta-analysis. Methods: The search for this study was a search term that combined stroke, virtual reality, and training, and the electronic search was conducted through EMBASE, MEDLINE, and Cochrane Library. As a result of the search, 21 studies satisfying the selection criteria of the target study were confirmed as the final analysis target. This study consisted of 21 randomized experimental studies and 21 randomized controlled trials, and the total number of participants was 642. [Experimental group (n=314), control group (n=328); total 642]. As a result of the study, upper extremity function was assessed using a box and block test, a modified Ashworth scale, and a scale including range of motion. The balance was evaluated by the berg balance scale. Gait was a Timed Up and Go test (TUG), stride length, and gait function. Scales including a walking rate scale were evaluated. The effect size for the intervention of the analytical study was meta-analyzed with the RevMan 5.3.3 program of the Cochrane library. Results: The results of the study showed that the function of walking was statistically significant. Balance showed statistically significant results. The upper extremity function showed no statistically significant results. Conclusion: Through this rehabilitation treatment by applying virtual reality environment to the rehabilitation of stroke patients in the future can be proposed as an effective intervention method for the balance and gait function of stroke patients.

• 대한통합의학회지
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• 제10권3호
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• pp.233-246
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• 2022

Purpose : The study aims to determine the effects of virtual and non-virtual realities in a normal person's mirror walk on gait characteristics. Methods : Twenty male adults (Age: 27.8 ± 5.8 years) participated in the study. Reflection markers were attached to the subjects for motion analysis, and they walked in virtual reality environments with mirrors by wearing goggles that showed them the virtual environments. After walking in virtual environments, the subjects walked in non-virtual environments with mirrors a certain distance away after taking a 5 min break. To prevent the order effect caused by the experiential difference of gait order, the subjects were randomly classified into groups of 10 and the order was differentiated. During each walk, an infrared camera was used to detect motion and the marker positions were saved in real time. Results : Comparison between the virtual and non-virtual reality mirror walks showed that the movable range of the leg joints (ankle, knee, and hip joints), body joints (sacroiliac and atlantoaxial joints), and arm joints (shoulder and wrist joints) significantly differed. Temporal characteristics showed that compared to non-virtual gaits, the virtual gaits were slower and the cycle time and double limb support time of virtual gaits were longer. Furthermore, spacial characteristics showed that compared to non-virtual gaits, virtual gaits had shorter steps and stride lengths and longer stride width and horizontally longer center of movement. Conclusion : The reduction in the joint movement in virtual reality compared to that in non-virtual reality is due to adverse effects on balance and efficiency during walking. Moreover, the spatiotemporal characteristics change based on the gait mechanisms for balance, exhibiting that virtual walks are more demanding than non-virtual walks. However, note that the subject group is a normal group with no abnormalities in gait and balance and it is unclear whether the decrease in performance is due to the environment or fear. Therefore, the effects of the subject group's improvement and fear on the results need to be analyzed in future studies.

• 실천공학교육논문지
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• 제5권2호
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• pp.117-122
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• 2013

첨단 IT 기술이 발달함에 따라 가상현실 기술이 빠르게 발달하고 있으며, 각 분야에서 가상현실 기술을 이용한 연구가 활발히 진행되고 있다. 가상현실을 활용한 분야로는 교육, 군사, 의료, 예술, 오락 등, 다양한 분야에서 연구가 진행되고 있다. 본 연구에서는 가상현실기술을 기술교육분야에 적용하여 다양한 형태의 가상훈련 콘텐츠를 개발하였으며 개발된 가상훈련 콘텐츠들을 유형별 분류하고 그 특징과 효과를 비교하고 분석하였다. 또한 가상훈련 콘텐츠를 기술교육에 실제 활용한 사례를 유형별로 조사하여 가상훈련 콘텐츠의 교육적 효과를 확인하였다.

• 한국CDE학회논문집
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• 제21권4호
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• pp.397-408
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• 2016

VR and AR are widely used in many applications to provide more immersive visualization and natural interaction for learning and experiencing virtual but realistic tasks. Energy saving is considered as one of the most important issues throughout the world in order to overcome global warming and energy crisis. In particular, the awareness of home energy saving is regarded as a first step to deal with this issue. In this paper, we suggest a new learning environment using virtual and augmented reality (VR/AR) for home energy saving experience. In particular, it presents a comparative study of the user experience in home energy awareness using immersive virtual reality and mobile augmented reality. The first person user experience using immersive VR wearing head mounted display (HMD) and the third person user experience using mobile AR are implemented and systematically compared with each other in terms of the learning effect of energy saving and qualitative usability. Implementation results will be given to show the advantage and effectiveness of the proposed approach.

• 대한기계학회논문집A
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• 제28권8호
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• pp.1116-1124
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• 2004

In these days, a vehicle simulator has been developed with a VR(Virtual Reality) system. A VR system must provide a vehicle simulator with natural interaction, sufficient immersion and realistic images. In addition, a VR system must present a driver with the realistic driving situation. To achieve these, it is important to obtain a fast and uniform rendering performance regardless of the complexity of virtual worlds. In this paper, the factors to improve the reality for the VR based vehicle simulator have been investigated. For the purpose, the modeling and the rendering methods which offer an improved performance for complex VR applications as the 3D road model have been implemented and verified. Then, we experiment on the influence of graphic and sound factors to the driver, and analyze each result for improving the reality such as the driver's viewport, the form of texture, the lateral distance of the side object, and the sound effect. These factors are evaluated on the driving system which is constructed for qualitative analysis. The research results could be used for improving the reality of the VR based vehicle simulator.

• 아동학회지
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• 제36권5호
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• pp.135-153
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• 2015

The purpose of this study was to investigate false belief understanding and justification reasoning according to information of reality amongst children aged 3, 4 and 5. Children aged 3 to 5 years (N = 176) participated in this study. Each child was interviewed individually and responded to questions designed to measure his/her false belief understanding. Every child responded to the false belief task under two different information conditions of reality(reality known vs reality unknown). For more specific analysis, children's reasoning responses were also recorded. The major findings of this study are as follows. Children could understand false belief more easily under reality unknown conditions. Specifically, the influences of information conditions were crucial to 3-year-olds but not to 4- and 5-year-olds. Although 3 year olds were able to avoid the systematical errors inherent in the false belief task, they still did not understand the false belief itself. This study provides specific aspects of false belief understanding and its relevance to general changes in cognitive development.