• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.471-474
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• 2002

본 논문은 온라인 VR 게임 엔진 개발의 일환으로 임의의 형태의 스크린에 대한 프로젝션 디스플레이 할 때 발생하는 왜곡현상을 자동으로 보정하는 시스템 구현 방법에 관한 것이다. 기존에는 모니터와 컴퓨터로 이루어진 일반적인 아케이드 게임의 형태로부터 다양한 VR 장비들과 다수의 사용자가 온라인상에서 게임을 즐기는 멀티 유저용 게임의 형태에 이르기까지 다양한 종류의 상품이 나와 있다. 새로운 VR 기술들이 점차 저가화 됨에 따라 사용자에게 새로운 몰입형 아케이드 게임환경을 제공하기에 이르렀다. 본 논문에서는 프로젝션 기법을 사용하여 단일화 된 디스플레이 스크린을 사용하지 않고 임의의 형태의 스크린에 대한 프로젝션 디스플레이 시스템을 구현하는 방법을 제안하여 협소한 공간에서도 게임 디스플레이가 가능하도록 한다. 또한 본 기술을 다수의 프로젝션 디스플레이로 확장하여 넘은 FOV(Field Of view)를 제공하는 방법을 제안한다.

• Journal of information and communication convergence engineering
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• v.17 no.3
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• pp.205-212
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• 2019

Motion tracking and localization devices are an important building block of motion tracking systems in a virtual reality (VR) environment. This study is about improving the accuracy of motion and location for enhancing user immersion in experience type VR environment to position tracking technique. In this study, we propose and test a design of such a device. The module data test of the attitude and heading reference system shows that the implementation with the MPU-9250 sensor is successful and adequate to be used with short operation time. We consider various sensor hardware dependencies of VR, and compare various correction methods and filtering methods to lower the motion to photon (MTP) time that user movement is fully reflected on the display using sensor devices. The Kalman filter is used to combine the accelerometer with the gyroscope in the sensing unit.

• Korean Journal of Computational Design and Engineering
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• v.18 no.4
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• pp.290-298
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• 2013

A walking navigation system (usually known as a locomotion interface) is an interactive platform which gives simulated walking sensation to users using sensed bipedal motion signals. This enables us to perform navigation tasks using only bipedal movement. Especially, it is useful for the certain VR task which emphasizes on physical human movement, or accompanies understanding of the size and complexity of building structures. In this work, we described system components of VR walking system and investigated several types of walking platform by literature survey. We adopted a MS Kinect depth sensor for the motion recognition and a treadmill which includes directional turning mechanism for the walking platform. Through the integration of these components with a VR navigation scenario, we developed a simple VR walking navigation system. Finally several technical issues were found during development process, and further research directions were suggested for the system improvement.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.4
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• pp.361-369
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• 2018

The ship surveyor makes a scheme of reasonable ship operation by examining whether the ship has been properly constructed in accordance with the rule of classification societies and international conventions or whether the facilities of the ship in operation meet the standard stipulated by law. Even though the ship surveyors of classification society generally consist of people who have the skill of design or operation of a ship, it takes a long time to train a surveyor to the maturity level. This paper describes the development of survey simulator based on virtual ship environment that enables the surveyor minimize trial and errors to survey the ships. By using VR(Virtual Reality) based survey simulator, surveyors possibly achieve improvement of competence in survey quality by means of safe and immersive training environment. In order to improve the usability and utility of the VR simulator, the ship 3D model has been generated using 3D CAD model for design and production in shipyard. Through this, we suggested the possibility of consistent use of 3D model as the digital twin of a ship.

• Physical Therapy Rehabilitation Science
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• v.9 no.3
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• pp.171-177
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• 2020

Objective: This study aimed to investigate the upper limb strength, active joint range of motion (AROM), and upper limb function in persons with chronic stroke using virtual reality training in combination with upper limb sensory stimulation. Design: Two-group pretest-posttest design. Methods: 20 subjects were divided into two groups of 10, the sensory motor stimulation and virtual reality training (SMVR) and virtual reality training (VR) groups. The training was conducted for 30 minutes per session, three times a week for 8 weeks.The participants' upper limb strength was measured via the hand-held dynamometer, joint angle AROM was measured via dual inclinometer, function was measured using the Jebson-Taylor hand function test and the manual function test. Results: Significant differences were observed in all groups before and after the training for upper extremity strength, AROM, and function (p<0.05). Between the two groups, the SMVR group showed significant improvement in muscle strength, AROM, and Jebsen-Taylor hand function test scores compared with the VR groups (p<0.05). Conclusions: In this study, we confirmed that sensory stimulation and VR had positive effects on upper extremity strength, AROM, and function of persons with chronic stroke. The results suggest that in the future, VR in combination with sensory stimulation of the upper limb is likely to become an effective method (a rehabilitation training program) to improve the upper limb function of persons with chronic stroke.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.109-119
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• 2011

The virtual reality (VR) technology has been used as the application of architectural presentation or simulation tool in the field of industry. The high immersion and intuitive visual information are the great merits of design evaluation or environmental simulation when we are using the virtual environments. But the distortion of distance perception in VR is still a big problem when the accuracy of distance presentation is strictly required. For example, distance estimation is especially important when the virtual environments are applied to the presentational tool for evaluation the space design or planning in the field of architecture. If there are some perception error between the built space in real and represented space in virtual, the accurate design evaluation or modification of design is hard to be carried out during the design development stage. In this paper, we have carried out some experiments about distance estimation in the immersive virtual environments to verify the factors and their influence. We made a hypothesis that the lack of the information for the user in VR causes the different distance estimation from the real world because users are usually comfortable with moving fast and long distance in VR environments compared with moving slow and short distance in real space. So, we carried out basic experiment to prove our hypothesis that the lack of information makes subjects estimate the distance of walking in VR shorter compared with the same distance in real. Also, among the factors that probably affect the distance estimation in VR, we have verified the influence of the image resolution. The influence of resolution degradation of image on the distance estimation was verified with the condition of static and dynamic images. The results showed that the resolution has deep relation with the distance estimation. For example, the subject underestimated the distance at the lower resolution condition. We also found the methods of the making the lower resolution image could affect on the visual perception of subjects.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.3 s.246
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• pp.231-240
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• 2006

Immersive virtual reality (VR) for the manufacturing planning helps to shorten the planning times as well as to improve the quality of planning results. However, VR equipment is expensive, both in terms of development efforts and device. Engineers also spend time to manually repair erroneous 3-D shape because of imperfect translation between 3-D engineering CAD model and VR system format. In this paper a method is proposed to link 3-D engineering CAD model to a multichannel visualization system with PC clusters. The multichannel visualization module enables distributed computing for PC clusters, which can reduce the cost of VR experience while offering high performance. Each PC in a cluster renders a particular viewpoint of a scene. Scenes are synchronized by reading parameters from the master scene control module and passing them to client scenes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.201-206
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• 1999

Though a demand for 3-D CG (Three-Dimensional Computer Graphics) drastically increases, traditional modeling system for virtual objects are very difficult to handle. Applying VR (Virtual Reality) technology is, however, able to make the modeling systems more efficiently and intuitively. In this paper, traditional modeling operations are analyzed and their problems are clarified. We discuss what can be improved with VR technology. Then, a guideline of merging VR technology into the modeling system is described. A new modeling system is proposed using a CAVE system which is utilized in the latest VR technology. This proposed system aids in creating 3-D objects with high immersion in VEs (Virtual Environments)

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.457-459
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• 2012

가상현실 환경은 사용자가 데이터와 상호작용하면서 직관적으로 데이터를 인지할 수 있게 해주는 인터페이스를 제공한다. 이런 가상현실 환경은 고해상도 디스플레이 장치에서 사실상 유일하게 사용할 수 있는 사용자 친화적인 인터페이스 방식이기도 하다. 본 논문에서는 고해상도 디스플레이 장치를 이용한 몰입형 가상현실 환경에서 사용되는 사용자 인터페이스 프레임워크를 소개하기로 한다. 이 인터페이스 프레임워크는 VR Juggler와 OSG(OpenSceneGraph)를 기반으로 하며, 다양한 형태의 디스플레이 장치를 이용한 몰입형 가상현실 환경에서 사용자가 가상현실과 상호작용하는데 필요한 기반 환경을 제공한다.

• Educational Technology International
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• v.21 no.2
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• pp.155-191
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• 2020

The aim of this study was to examine the trends (e.g., the distribution of the studies by year, country, research methods, and participants' education level) and fundamental findings [e.g., interaction in Virtual Reality (VR) environments, educational content through VR and Augmented Reality (AR) technologies, learning environment in AR, etc.] regarding immersive learning technologies such as VR and AR in English Language Teaching (ELT) between 2010 and 2019. Employing a systematic review research methodology, data was gathered from 59 academic articles published in the following databases: EBSCOhost, ERIC, Web of Science, and Taylor & Francis. The studies were analyzed using a content analysis approach, and findings demonstrated that immersive learning technologies in ELT came to prominence in 2017. Mixed methods research was the most widely employed research method. The most studied language skill was vocabulary for AR and speaking for VR. The results also revealed advantages and challenges with regards to the use of immersive learning technologies in ELT. Further analysis illustrated the findings related to characteristics of immersive learning technologies in ELT. Based on this review, research and design implications for researchers and practitioners are presented.