• Journal of KIISE
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• v.45 no.3
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• pp.251-279
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• 2018

Users can experience cybersickness when interacting with virtual reality (VR). The symptoms of cybersickness are similar to those of motion sickness which include eye fatigue, disorientation, and nausea. Despite the longstanding interest of user's discomfort, inconsistent results have been drawn on the underlying mechanisms and solutions of cybersickness. In this study, we propose an integrated view of cybersickness connecting causes of the symptoms, human perception model, and measurements of cybersickness. Cybersickness-related factors of previous research are reorganized into content, hardware, and human factors as well as analyzed in terms of VR fidelity. Also, pros and cons that measure the degree of cybersickness are discussed.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.53-59
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• 2007

A navigation system for virtual environments using low-qualify HMD(head mounted display) must quantize images when the system presents true-color image with restricted number of colors. Such navigation system quantizes an image by using fixed palette. If the system represents an image by using a variable palette which is made considering a region around the viewpoint then user can perceive a virtual environments more vividly because human visual system is sensitive to the colors variation in the region around the viewpoint. In this paper we propose a color quantization algorithm that quantize a region around the viewpoint more finely than other regions at each variation of viewpoint for virtual environments navigation system and compose virtual environments navigation system using proposed algorithm. The system quantizes an image at each variation of viewpoint and shows a quantized image to user through HMD. We tested user preferences for our proposed system and the results show that users preferred our system.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.5
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• pp.1-11
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• 2020

Image-based virtual try-on (VTON) is becoming popular for online apparel shopping, mainly because of not requiring 3D information for try-on clothes and target humans. However, existing 2D algorithms, even when utilizing advanced non-rigid deformation algorithms, cannot handle large spatial transformations for complex target human poses. In this study, we propose a 3D clothing reconstruction method using a 3D human body model. The resulting 3D models of try-on clothes can be more easily deformed when applied to rest posed standard human models. Then, the poses and shapes of 3D clothing models can be transferred to the target human models estimated from 2D images. Finally, the deformed clothing models can be rendered and blended with target human representations. Experimental results with the VITON dataset used in the previous works show that the shapes of reconstructed clothing are significantly more natural, compared to the 2D image-based deformation results when human poses and shapes are estimated accurately.

• Journal of Digital Convergence
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• v.19 no.3
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• pp.195-202
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• 2021

This study is a systematic review study to confirm the characteristics, effects, and application strategies of domestic and foreign virtual reality programs provided by dementia education. This study is based on the literature published up to July 2020, CINAHL, Cochrane, EMBASE, and Pubmed electronic databases were used overseas, and RISS, KISS, and DBpia were searched in Korea. Based on the selection criteria and exclusion criteria, the final six papers were used for analysis. As a result of the analysis, the subjects of the selected literature were two informal caregivers (33.3%), one general (16.7%), and three students (50.0%) including nursing students and medical and pharmacy students. The virtual reality program was effective in a total of five areas(empathy ability, dementia attitude including knowledge and comfort of dementia, trust in own abilities, dyadic relationship scale), of which 75% of the studies measured empathy ability had significant effects. The results of this study confirm that virtual reality technology can be used for human-centered nursing based on empathy.

• Archives of design research
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• v.12 no.4
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• pp.294-303
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• 1999

With the breakthrough development of computing environment, the design phases have been changed a lot nowadays. In the case of prior phases of transportation design such as cars and forklift-trucks design, designers have depended on surveys and 2D line drawings for fixing a product layout and extracting ergonomic data. In this method, designers don't meet only the problem of reliability of measuring data but also, the problems of unknown situation of operators' fatigue and comfort in work situation. In these methods, it has much less creditability to have a 2D human model to check the real world motion due to the limitation of the 3 Dimension. Even though with a 2D human model, perfect layout is determined, it is still difficult to measure about comfort and fatigue for a user because it measuring an analysing method is static. The development of computer hardware and software have not only changed the flow in the social-wide range but also immerged design into Virtual Environment. In conventional design method, visualization and data transferring have been the main issues but, in virtual environment, determining of design layout and analysing ergonomic data with sophisticated feeling about comfort and fatigue are possible by using 3D virtual human. In this study, the general characteristics of virtual environment was discussed and the possibility of digital process of design was treated. For these studies, layout design for forklift-trucks was tested. Eventually, the merits of each design phase applied virtual environment are discussed.

• Korean Journal of Cognitive Science
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• v.17 no.4
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• pp.357-373
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• 2006

Virtual reality (VR) provides a virtual experiment (VE) context consisting of information presented to the senses of the user. The user perceiver and interprets the VE context, and then naturally recognizes a level of realism in the VE. Presence is often thought of as the sense of 'being there' in the n. Presence includes overall feelings about the information conveyed from a virtual avatar to the user. Therefore, there must be brain mechanisms for integrating sensory information about presence.'Feeling of presence' is related with the user's cognition and perception about information on communication through medium. Thus 'feeling of presence' may characterize perceptual mechanisms in the brain. We studied these mechanisms by presenting a VR that consisted of an avatar telling a story about a social conversation. We performed covariance analysis on subjective brain activity (fMRI) during the story presentation with a presence score. The data analysis revealed that activity in several brain areas was correlated with the presence store. A positive correlation was shown in the right lingual gyrus, right cuneus, left lingual gyrus, right fusiform gyrus, left inferior temporal gyrus, anterior cingulate cortex and right posterior cingulate cortex of the brain. This study showed the brain mechanism to be related the feeling of presence and brain activities in our subjects, using VR to communicate information.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.1-5
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• 2009

In this paper, we develop a haptic mouse system for immersive human computer interaction. The proposed haptic mouse system can provide vibrotactile feedback as well as thermal feedback for realistic virtual experience. For vibrotactile and thermal feedback, we use eccentric motors, a solenoid, and a peltier actuator. In order to evaluate the proposed haptic mouse, we implement a racing game prototype system. The experimental result shows that our haptic mouse is expected to be useful in experiencing virtual world.

• IE interfaces
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• v.18 no.1
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• pp.82-87
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• 2005

Most of virtual reality systems ask users to control 3D objects or to navigate 3D world using 3D controllers. To maximize the human performance in the control, the design of virtual reality system and its input and output devices should be optimized. In this study, an experiment was designed to investigate the effects of three resolution factors of a virtual reality system on the human performance. Six subjects conducted the experiment for the factors; two frame rates, three spatial resolutions, and three pictorial contents. The result showed that the greater the spatial resolution was, the higher the human performance was. For the temporal resolution, fixed frame rate at 18 Hz was better than the varied maximized frame rate. For the pictorial contents, the virtual space with orientation cues marked the greatest performance than the other two conditions; the virtual space without any orientation cue and the virtual space like real world. These results could be applied for the design of virtual reality systems.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.312-313
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• 2012

단청의 열화현상에 대한 연구는 주로 건축재로서의 내구성 향상에 초점을 두고 연구가 진행되고 있으나 본 연구는 가상유적지 재현을 위해 가상 건축물의 사실감을 높이기 위한 방안으로서 열화현상을 분석하고 가시화 하는데 초점을 두었다. 이를 위해 먼저, 전통건축에 나타나는 단청의 열화과정을 인간이 인지하는 색채감의 변화에 초점을 두고 연구를 진행한다. 우리나라 단청에서 사용된 안료를 살펴보고 문화재관리청에서 선정한 무기안료와 유기안료를 중심으로 내후성 시험을 통해 안료의 열화현상을 분석한다. 단청의 열화를 크게 색변과 박리 현상으로 나누어 촉진내후성시험기를 통해 얻어진 결과를 토대로 목조 전통건축의 열화현상을 분석한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.04a
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• pp.486-489
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• 2016

가상현실 기반 훈련시스템은 3D 모델링 기법으로 개발되어 실시간 렌더링(Realtime Rendering)되는 훈련용 콘텐츠와 운동감 제공을 위한 모션플랫폼, 촉감 제공을 위한 햅틱장치 등 다양한 하드웨어를 이용하여 인간 감각에 대한 모의 체험환경을 제공함으로써 높은 훈련 몰입감을 제공한다. 훈련시스템의 구성요소 중 하드웨어들은 설계 성능을 바탕으로 정량적 시험평가로서 검증(Verification)과 확인(Validation)이 가능하나, 훈련환경에 대한 사실적 가시화가 요구되는 훈련용 콘텐츠는 시현을 위한 실시간 렌더링 성능 등의 정량적 시험평가 만으로 검증과 확인에 어려움이 많다. 본 연구에서는 일반 소프트웨어와 콘텐츠 소프트웨어 테스팅 요소 차이와 상용게임 콘텐츠와 훈련용 콘텐츠의 차이점을 분석하고, 훈련용 콘텐츠의 정량적 시험평가를 위한 명세서의 작성과 활용을 제안한다.