• PNF and Movement
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• v.16 no.2
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• pp.259-266
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• 2018

Purpose: This study aimed to compare balance ability according to the immersion level of virtual reality-based training for the balance enhancement of the elderly. Methods: This study included 48 elderly people aged 65 years and older (male 16, female 32). According to the immersion level of applied virtual reality training, 16, 17, and 15 persons were randomly assigned to full immersion, semi-immersion, and control groups. The subjects who were assigned to the full immersion group and semi-immersion group received virtual reality training for 6 weeks at 20 min at a time, 3 times per week. The control group received no intervention. Balance ability was evaluated by measuring the stability limit and the tandem walking test before and after the intervention. Results: Results showed significant differences among the three groups in the limit of stability of all directions and the tandem walking test after the intervention. The results of the limit of stability showed a significantly higher value in the full-immersion group than in the control group, and the results of the tandem walking test showed a significantly lower value in the full-immersion and semi-immersion groups than in the control group. Conclusion: The results indicate that the head-mounted display equipment for applying full-immersion virtual training is the most effective in enhancing the balance ability of the elderly.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.772-774
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• 2008

A navigation system for virtual environments using low-quality 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.

• Physical Therapy Korea
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• v.22 no.3
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• pp.41-49
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• 2015

This study aimed to evaluate the surface area and velocity of center of pressure (COP) during one leg standing by stimulating the sensory system in normal adults. Thirty subjects were enrolled in this study. Subjects were asked to stand on one leg during testing conditions. Testing conditions included 6 different sensory stimulations as follows: eyes opened, eyes closed, eyes opened with vibrator, eyes opened with head-mounted display (HMD), eyes opened with vibrator and HMD, and eyes closed with vibrator. During each testing condition, the surface area and velocity of center of pressure were measured. There were significant differences in the mean surface area and the mean velocity of COP between the "eyes opened" condition and the other five testing conditions (p<.05). However, in the comparison between the "eyes closed" and "eyes opened with HMD" conditions, there were no significant differences in the tested parameters. This study shows that closing eyes or keeping eyes opened while using HMD to experience virtual reality has the same effect on one leg standing balance. This finding should be considered in the evaluation or intervention of balance, especially one leg standing balance and balance while standing with a small base of support.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.3
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• pp.1-8
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• 2017

Recently, the development of the head mounted display (HMD) device has attracted a great deal of attention to the actual contents. Especially, Augmented Reality (AR), which is a mixture of actual information and virtual world information, is focused on. AR HMD is able to interact by arranging virtual objects in real space through spatial recognition using depth camera. In order to naturally mix virtual space with real space, it is necessary to develop a technology for realizing spatial mapping information with high accuracy. The purpose of this paper is to evaluate the optimal configuration of augmented reality application program by realizing accurate spatial mapping information when mapping a real space and an object placement environment using HoloLens. To do this, we changed the spatial mapping information in real space to three levels, which are the number of meshes used in cubic meters to scan step by step. After that, it was compared with the 3D model obtained by changing the actual space and mesh number. Experimental result shows that the higher the number of meshes used in cubic meters, the higher the accuracy between real space and spatial mapping. This paper is expected to be applied to augmented reality application programs that require scanning of highly mapped spatial mapping information.

• Journal of Broadcast Engineering
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• v.25 no.1
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• pp.113-116
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• 2020

This paper proposes a Quality of Experience (QoE) evaluation experiment to measure the effects of 360-degree video and sensory effects on the subject's degree of immersion, satisfaction, and sense of presence. The test subject responds to a questionnaire about the degree of immersion, satisfaction, and sense of presence after experiencing a 360-degree video accompanied by sensory effects while wearing a head-mounted display (HMD) with a scent diffusion device. As a result of the response analysis, it was confirmed that the proposed experimental method is suitable for measuring the subject's degree of immersion, satisfaction, and sense of presence about 360-degree video and sensory effects. On the other hand, inserting a gray screen for comparison experiments while watching a 360-degree video was found to cause a significant decrease in immersion and realism.

• Journal of the Institute of Convergence Signal Processing
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• v.19 no.3
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• pp.133-138
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• 2018

VR technology is a technology that allows a user to experience virtual reality close to reality by wearing an HMD (Head Mounted Display) device. Recently, as the interest in VR technology increases due to the 4th industrial revolution, various HMD devices are spreading. As a result, VR technology is being rapidly applied to various fields, but many of them still experience VR nausea. VR nausea is caused mainly by visual factors, unlike motion nausea, such as car nausea, sea nausea, and air nausea. Such occurrence of VR nausea may be caused by the characteristics of visual information of VR video contents, the hardware characteristics of HMD devices blocking the external visual field, or the physical specificity of individuals, and it is difficult to distinguish the causes. In this paper, we aim to analyze the characteristics of Visually Induced Motion Nausea images focusing on VR video content, which is the cause of VR nausea, in order to search for minimization of Cyber sickness occurrence.

• 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 Platform Technology
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• v.6 no.2
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• pp.3-9
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• 2018

Recently VR environment is used in many areas including mobile learning, smart factory. However HMD(head-mounted display) is required to a dedicated and expensive system with high-end specification. When designing a VR system, it is needed to handle performance, mobility and usability. Many VR applications need to handle diverse sensors and user inputs continuously in a streaming manner. In this paper we design a VR mobile platform and implement a low-cost mobile VR HMD running on the platform. The VR HMD supports 3D contents delivery in a mobile manner. It is used to detect the motion detection based on angle value of a VR player from accelerator and gyro sensor. The MPU-6050, 6-axis sensor, is used to get a sensory value and the sensory value is taken as an input to a VR rendering server on a Unity game engine that is generated 3D images.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.165-170
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• 2020

In this study, after applying VR 360-degree video contents for intravenous infusion education, basic data on whether VR 360-degree video can be applied as educational content in the future is prepared by grasping the empathy and flow of nursing students in graduating grades. The VR 360 degree intravenous infusion educational content was developed in four-step process of planning, production, modification and completion. The design of this study was descriptive research, and the study period was from November 9 to November 22, 2019. The subjects of this study were 4th grade nursing students at a university, totaling 64 students. Nursing students watched VR 360 degree intravenous infusion educational content using HMD(head mounted display) under the safety management of the researcher. As a result of the study, the empathy of nursing students was 5.32±0.88 points and the flow was 6.02±0.84 points out of 7-point scale. The VR 360 degree intravenous infusion educational content developed in this study can be used as an educational medium in subjects and comparative departments, and it is necessary to specifically develop and verify teaching and learning methods in future studies.

• Journal of Digital Contents Society
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• v.18 no.2
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• pp.275-282
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• 2017

With the development of digital technology, a cinematic content has been changed into various forms. Web and mobile platforms bring new forms of cinematic contents. However despite of fast growing of VR(Virtual Reality) technology, they haven't applied to cinematic contents yet. This research focused on the esthetical use of rotoscoping technique for the Virtual Reality Cinema based on the (HMD) Head Mounted Display. First, we look though on VR films 'Notes on Blindness' and 'Pearl' to find how these films express esthetical virtual space. Through this, we found out graphical space provide new esthetical experience to viewers in virtual space. Also, we analyze fantastical usages and successful cases of rotoscoping technique with the 'Waking Life' and 'Scanner Darkly' that utilize rotoscoping technique to live action image. Lastly, we utilize rotoscoping technique esthetically to the VR film 'Girl on a swing' to fulfill the viewers experience and desire.