• 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.

• The Journal of Korean Physical Therapy
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• 제31권5호
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• pp.273-278
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• 2019

Purpose: The purpose of this study was to investigate the effects of three-dimensional virtual reality horse riding simulator training using a head-mounted display on gait and balance in children with cerebral palsy. Methods: Ten children with cerebral palsy were randomly assigned to the horse riding simulator (HRS) group (n=5) or the horse riding simulator with virtual reality (HRSVR) group (n=5). To evaluate balance, center of gravity (COG) sway velocity and total sway distance of each group were assessed using the Wii balance board, and gait speed and stride length of each group were assessed using a gait analysis system. Results: Intra-group comparisons between pre- and post-intervention measures revealed that there were significant changes in all gait and balance variables such as stride length, gait velocity, COG sway velocity and COG sway distance in the HRSVR group (p<0.05). In the HRS group, there were significant changes in all variables except stride length (p<0.05). In addition, inter-group comparisons showed significant differences between the two groups in stride length, gait velocity and COG sway distance except COG sway velocity (p<0.05). Conclusion: The findings of this study suggest that horse riding simulator training combined with 3D virtual reality can be a new positive therapeutic approach for improving functional performance in children with cerebral palsy.

• 한국정보처리학회논문지
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• 제5권6호
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• pp.1603-1609
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• 1998

본 고에서는 Virtual Group 네트워크 서비스 제공을 위한 IP 주소 변환 시스템의 개발과 이를 초고속 시범 서비스에 적용한 예에 관하여 다루었다. 이러한 방법은 전용 망에 접속된 지역 망 내의 제한된 가상 그룹에 대해 별도의 전용 네트워크 서비스를 제공할 수 있는 방안이 될 수 있으며, 향후 관심이 부각되고 있는 인트라넷 환경에서 폐쇄 그룹 내부에서의 모든 업무를 인터넷 관련 기술로 처리하는 새로운 개념의 네트워크 환경을 제공하는데 이용될 수 있다.

• 정보교육학회논문지
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• 제2권2호
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• pp.226-238
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• 1998

본 연구에서는 초속망의 원격교육을 지원하는 그룹 관리 시스템을 연구하였다. 효율적인 원격교육을 위해서는 가상클래스 상의 피관리 객체와 그 동작들을 관리, 제어하는 메카니즘이 필요하며, 교수자는 학습그룹 및 하나의 학습그룹을 형성하는 학습자의 다양한 상태변화를 직시할 수 있어야 한다. 그리고, 가상클래스 상에서 교수자와 학습자는 학습그룹에 따라 토론하고 상호 메시지 송수신이 가능해야 한다. 본 논문에서는 이러한 가상클래스 운용을 위한 그룹 관리 및 관리정보베이스 모델을 제안하고 거기에 요구되는 그룹관리 알고리즘을 연구하였다.

• The Journal of Korean Physical Therapy
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• 제21권2호
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• pp.31-38
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• 2009

Purpose: This study was examined the effect of training using a Virtual Reality System on the sitting balance and Activities of Daily Living for patients with a spinal cord injury. Methods: The subjects were divided into an experimental (6 persons) and control group (5 persons). The experimental group trained the 5 programs, three times per week for 6 weeks using the Virtual Reality System and five days for week using conventional physical therapy. The control group trained five days for a week using conventional physical therapy. Results: The difference in the mean Spinal Cord Independence Measurement (SCIM) score in the experimental and control groups was increased to 8.33 and 6.60 (p=0.79), respectively. The difference in the mean functional reaching test in experimental and control group increased to 4.21 and 1.09 (p=0.25), respectively. The difference in the mean sitting time in experimental and control group increased to 41.05 and 10.33 (p=0.66), respectively. There was a difference in the mean of all variances but these differences were not statistically significant. Conclusion: These results suggest that training using the Virtual Reality System increased the SCIM, functional reaching test and sitting time in people with a spinal cord injury.

• PNF and Movement
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• 제18권2호
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• pp.183-194
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• 2020

Purpose: Functional ankle instability (FAI) causes tension in the joints, ligaments, and tendons, and the impact on visual and vestibular organs leads to imbalance. This study compared the effects of a traditional balance training program to virtual reality training to improve FAI. Methods: Twenty-four participants with FAI (CAIT score < 24) were assigned to a virtual reality training group (n = 13) and a traditional balance training group (n = 11). Both groups pursued their respective training program for four weeks. After a ten-minute warm-up, participants completed a 30-minute training session, three times per week. The traditional balance training group underwent static and dynamic training using a balance board and a stability trainer pad while the virtual reality group underwent balance training using a virtual reality program. Biorescue was used to measure changes in the speed and length of center of pressure (COP) for single-leg stance pre- and post-training. Results: The speed and length of COP improved significantly in both groups after training as compared to before (p < 0.05). However, there were no significant differences in these outcomes between the virtual reality training group and the traditional balance training group (p>0.05). Conclusion: The study findings confirm the effectiveness of both virtual reality training and traditional balance training in reducing ankle instability, with no difference in treatment effects.

• Journal of Information Technology Applications and Management
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• 제17권3호
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• pp.83-97
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• 2010

The purpose of this study is to examine the impacts of media symbol variety on group performance in virtual teams. Symbol variety is defined as the number of ways in which information can be communicated and includes Daft and Lengel [1986]'s multiplicity of cues and language variety. According to media richness theory and media synchronicity theory, the use of media with high symbol variety is assumed to facilitate and promote communications among virtual team members. Therefore, it is expected that the media symbol variety is positively associated with group performance in virtual teams. Furthermore, online relationship building is expected to mediate the impacts of symbol variety on the performance. To confirm the suppositions, a controlled lab experiment was conducted with 60 undergraduate students as subjects. In the experimental virtual teams, subjects were allowed to communicate with other members using text-based messenger with emoticons. Subjects in the control virtual teams were allowed to communicate using only text-based messenger. The direct impact of symbol variety on group performance in virtual teams was found insignificant. However, the online relationship was found to completely mediate the positive impact of symbol variety on group performance. The implications and limitations of this study are also discussed for future research.

• The Journal of Korean Physical Therapy
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• 제21권3호
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• pp.33-40
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• 2009

Purpose: This study examined the effects of a virtual reality-based exercise program on the functional recovery of balance and gait in chronic stroke subjects. Methods: A total of 42 chronic stroke patients were enrolled in this study. The participants were allocated randomly to 2 groups: a VR (n=22) and control group (n=20). Both groups received treadmill training for 3 sessions (10 minutes each), 30 minutes per week over a 6 week period. The VR group practiced additional virtual reality programs consisting of 3 programs for 10 minutes each. The data was analyzed using a paired t-test and independent t-test to determine the statistical significance. Results: The virtual reality-based exercise group showed significant increases in gait velocity, cadence and stride length compared to the control group (p<0.05). However, there were no significant differences in static balance. Conclusion: These results support the perceived benefits of exercise programs that incorporate virtual reality to augment the balance and ambulation of stroke patients. Therefore, virtual reality is feasible and suitable for stroke patients

• 국제물리치료학회지
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• 제5권2호
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• pp.730-737
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• 2014

The aim of this study is to examine the effects of virtual reality cognitive rehabilitation program on cognitive function, physical function and depression of long-term care insurance nongrading elderly dementia using Daytime protection service. For achieve this purpose, 30 dementia elderly were randomly assigned in to the experimental group(n=15)and control group(n=15). All subjects performed a general therapeutic exercise and 20- 30minutes takes virtual reality cognitive rehabilitation program were conducted with experimental group 2 times a week for 8 weeks. The intervention effects were measured by using cognitive function is mini-mental states examination-Korean version(MMSE-K), visual perception is MVPT(Motor-Free Visual Perception Test), Berg's balance scales(BBS), depression test GDS-K and lower limb strength. The results of study represented that the training group showed significant improvement in MMSEK( p<.05), visual perception(p<.05), balance(p<.05), lower limb strength(p<.05) and depression (p<.05). In conclusion, the virtual reality cognitive rehabilitation training using improves visual perception included cognitive function, physical function included balance, and lower limb strength and depression. These results suggest that virtual reality training using virtual reality cognitive rehabilitation program is feasible and suitable for mild dementia.

• 제어로봇시스템학회논문지
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• 제21권8호
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• pp.709-712
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• 2015

This paper will introduce the development case study about virtual-reality-based operation training system for steel making process. Steel making process consist iron making process to create liquid steel, pig iron, by reduction process, steel making process to make molten steel by refining, continuous casting process to make slab, and rolling process to make final product like coil, plate. This steel making process deals with liquid and solid products, so facilities of steel making process are very various and complicated. In addition, according to various customer requirements, the recycle of facilities and recipes changing have been fast. So the training for skilled operators is very important point. In this paper, we develop steel making training system based virtual reality for training skilled operator. This system consists of virtual machine, virtual HMI, and virtual control panel. And for fitting the characteristics of each process and increasing the education effectiveness, we develop dynamic methods like the method of dynamic education system configuration, initial facilities setup operation education system, and etc.