• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.13-27
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• 2020

Purpose: The purpose of this study is to present a recoil measurement and analysis of K2 rifle for the development of a virtual reality marksmanship training in the Republic of Korea Army. Methods: For the recoil measurement, a test-bed is built by a barrel that has exact dimensions of K2 rifle and three piezoelectric pressure sensors mounted on the barrel. Data of over 200 rounds of 5.56mm M193 and K100 bullets are collected and analyzed from live fire experiments. For the recoil analysis, both the free recoil method and the gas exhaust aftereffect method are used to calculate a recoil velocity, momentum and kinetic energy of K2 rifle by applying the law of conservation of momentum. In addition, a new method is proposed that uses the third law of motion and the chamber pressure model for the recoil measurement Results: The results show how different between the previous and proposed methods with respect to M193 and K100 bullets of K2 rifle. In M193, the free recoil method demonstrates 1.113, 4.197, and 2.335, the gas exhaust aftereffect method computes 1.698, 6.407, and 5.441, and the proposed method calculates 0.990, 3.734, and 1.848 in recoil velocity, momentum and kinetic energy, respectively. In K100, the free recoil method demonstrates 1.190, 4.487, and 2.669, the gas exhaust aftereffect method computes 1.776, 6.699, and 5.949, and the proposed method calculates 1.060, 3.998, and 2.119 in recoil velocity, momentum and kinetic energy, respectively. Conclusion: This study implements live fire experiments to provide recoil velocity, momentum, and kinetic energy of K2 rifle using both M193 and K100 bullets. For the development of the army virtual reality marksmanship, the results in this paper would be useful to design and produce a gun and/or a rifle of virtual reality.

• PNF and Movement
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• v.17 no.3
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• pp.369-378
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• 2019

Purpose: This study investigated the effects of virtual reality-based task training (VRBTT) using a smart glove on upper extremity function and activity of daily living in stroke patients. Methods: Twenty-nine patients with chronic stroke disease were randomly allocated to two groups: the VRBTT group (n=14) and the control group (n=15). All patients received 30 minutes of standard occupational therapy, 5 times a week, for 8 weeks. The VRBTT group performed an additional 30 minutes of virtual reality-based rehabilitation training, 5 times a week, for 8 weeks. Results: Both groups showed significant improvements in upper extremity function, yielding an increase in FMA and K-WMFT (p<0.05). There was a more significant increase in the VRBTT group before and after interventions (p<0.05). There was no significant difference in MAS for the control group (p>0.05); however, there was a significant increase for the VRBTT group (p<0.05). In the activities of daily living, there was a significant difference in the values for K-MBI (p<0.05). In addition, both groups showed a significant increase for K-MBI and K-RNLI (p<0.05). Conclusion: This study showed that VRBTT using smart gloves can have a more positive effect on upper extremity function and activities of daily living in stroke patients than conventional intervention methods. A variety of virtual reality-based contents and glove-shaped wearable devices will help stroke patients in rehabilitation clinics recover and return to society.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2670-2677
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• 2014

The technique of virtual machine construction using hypervisor such as Xen and KVM is mainly used for implementation of cloud computing infrastructure. This technique is efficient in allocating and managing resources compared to the existing operation methods. However it requires high resource usage when constructing virtual machines and results in wasting of resources when not using the allocated resources. Docker is a technique based on the container method to resolve such a problem. This paper shows the container method such as Docker is efficient as a web construction technique by comparing virtual machine method to container method. It is shown to be especially useful when storing data into DB or storage devices in such environments of web server or program development. In the upcoming cloud computing environment the container method such as Docker is expected to improve the resource efficiency and the convenience of management.

• The Korean Journal of Emergency Medical Services
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• v.26 no.3
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• pp.137-148
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• 2022

Purpose: This study aims to provide essential data for developing educational methods and content, tailored for the prehospital field situation, by analyzing the effects of education regarding the management of cardiac arrest. Methods: This study is a primitive experimental study of 55 new firefighters in C Fire Service Academy. Data were collected from the training which was imparted using the CPR virtual reality simulation program (CBS 2.0) in accordance with COVID-19 quarantine rules and social distancing. Data were analyzed utilizing SPSS version 25.0. Results: After VR simulation training, knowledge about performing CPR (14.85) and self-efficacy (4.12) were significantly high (p<.001). Learning immersion was also high (3.99±0.59), but learning satisfaction was even higher (4.34±0.62). Depending on the recruitment field, firefighters showed higher learning immersion (4.04±0.58 vs 3.68±0.63) and self-efficacy (4.16±0.55 vs 3.91±0.84) than 119 EMTs' but, there was no significant difference between them. In contrast, The quality of performance of CPR by EMT's was significantly higher than that of firefighters (p=.025). Depending on previous simulation experience, there was no significant difference among dependent variables. Conclusion: Virtual reality simulation shows positive results in learning immersion, learning satisfaction, self-efficacy, and performance of CPR. Therefore, we propose that virtual reality simulation training can be a new educational paradigm.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.128-136
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• 2014

The virtual try-on technologies of the current level have limitations with material expression as well as some difficulties with commercialization. There are differences in simulation results and subjective evaluations perceived by consumers according to the types and physical characteristics of materials used in virtual try-on simulations. This study were to analyze the exterior clothing shapes and visual images from 3D virtual try-on simulations with materials whose drapability was differentiated and then test the accuracy of the expression of the drapability of the materials. The study carried out 3D virtual try-on simulations by selecting flared skirts as an item to best express differences in drapability along with five materials of different physical properties and offered some basic data for greater utilization of virtual try-on simulations by comparing and analyzing them with the exterior shapes and visual images of actual flared skirts. The analysis results of hemline shapes between actual and virtual try-on according to the types of materials showed no match among the quantitative items of exterior shapes factors. There were no significant differences in the visual images except for "soft" according to the simulation methods, which means that the items can serve as part of a scale for visual image comparison. It is necessary to reflect quantitative numbers regarding "drapability" proposed in the study simulation software and to continue to build a systematic database for virtual simulations by investigating and testing various materials.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1627-1635
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• 2001

Virtual manufacturing is a technology facilitating effective development and agile manufacturing of products via sophisticated computer models representing physical and logical schema and behavior of real manufacturing systems including manufacturing resources, environments, and products. For the successful application of this technology, a virtual plant as a well-designed and integrated environment is essential fur sharing information and engineering collaboration among diverse engineering activities. The systematic approaches and effective methods for construction and application of a virtual plant are proposed in this paper, such as a 3-D CAD modeling, cell and line simulations, databases and some information technologies. Measuring and 3-D CAD modeling technologies of many equipments, facilities and structures of the building are developed, and effective information management system managing CAD models, related files and data is implemented in WWW environments. Finally, precise simulations of unit cell lines and the whole plant are performed. For the beginning of implementing a Virtual Automotive Plant, the Virtual Plant fur the Body Shop of a Korean automotive company is constructed and implemented. We could obtain the benefit of savings in time and cost in many manufacturing preparation activities in the new car development processes.

• PNF and Movement
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• v.18 no.2
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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.

• Archives of Plastic Surgery
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• v.49 no.5
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• pp.676-682
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• 2022

Background Virtual education is an evolving method for teaching medical learners. During the coronavirus disease 2019 pandemic, remote learning has provided a replacement for conferences, lectures, and meetings, but has not been described as a method for conducting a cadaver dissection. We aim to demonstrate how learners perceive a virtual cadaver dissection as an alternative to live dissection. Methods A virtual cadaver dissection was performed to demonstrate several upper extremity nerve procedures. These procedures were livestreamed as part of an educational event with multimedia and interactive audience questions. Participants were queried both during and after the session regarding their perceptions of this teaching modality. Results Attendance of a virtual dissection held for three plastic surgery training institutions began at 100 and finished with 70 participants. Intrasession response rates from the audience varied between 68 and 75%, of which 75% strongly agreed that they were satisfied with the virtual environment. The audience strongly agreed or agreed that the addition of multimedia captions (88%), magnified video loupe views (82%), and split-screen multicast view (64%) was beneficial. Postsession response rate was 27%, and generally reflected a positive perspective about the content of the session. Conclusions Virtual cadaver dissection is an effective modality for teaching surgical procedures and can be enhanced through technologies such as video loupes and multiple camera perspectives. The audience viewed the virtual cadaver dissection as a beneficial adjunct to surgical education. This format may also make in-person cadaver courses more effective by improving visualization and allowing for anatomic references to be displayed synchronously.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.155-164
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• 2021

Purpose : The purpose of this study is to investigate the effects of transcranial direct current stimulation and virtual reality program application on cognition and depression of patients with mild cognitive impairment, and to find an intervention method that can enhance active participation of patients with mild cognitive impairment. Methods : In this study, 50 mild cognitive impairment patients were divided into a treatment group (25 patients) and a control group (25 patients). The treatment group was applied with a transcranial direct current stimulation and a virtual reality program, while the control group received a placebo transcranial direct current stimulation and a virtual reality program. Both groups received five 50-minute sessions per week (one session per day) for six weeks (total of 30 sessions). NCSE was used to evaluate the cognitive functions of the patients before and after treatment intervention. Moreover, K-BDI was conducted to examine the depression of the patients. Results : As a result of the transcranial direct current stimulation and a virtual reality program intervention, the cognitive function of both treatment and control group significantly (p<.05) improved, and the depression of both treatment and control group significantly (p<.05) decreased. Moreover, the changes in cognitive functions and depression were significant between the two groups¸ treatment and control group (p<.05). Conclusion : The results of the study showed that the application of the transcranial direct current stimulation and virtual reality program significantly improved the cognitive function of mild cognitive impairment patients and decreased the depression of them. Therefore, it could be concluded that the transcranial direct current stimulation and virtual reality program was an intervention method which positively affects the cognitive function and depression of mild cognitive impairment patients.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.1
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• pp.109-124
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• 2024

Purpose : The purpose of this study was to examine the effects of a virtual reality-based complex cognitive training program for depression, cognitive function, and digital divide reduction in the elderly who have not been diagnosed with dementia or MCI. Methods : We enrolled 16 participants who were over 65 years old and not been diagnosed with dementia or MCI. We randomly divided into three groups (A, B, C). Participants underwent an 8-week virtual reality-based complex cognitive training program (60 minutes each session, twice per week). At a baseline, all participants completed questionnaires on general features, depression and cognitive function. After four weeks, all participants completed questionnaires on depression and cognitive function. After the end of the last program, participants conducted questionnaires on depression, cognitive function, and usability evaluation. Results : At the 8-week follow-up, 16 participants completed the program. Compared to the baseline, the average score of cognitive function was increased (from 26.5 to 28.5), although it was not statistically significant (p<.061). There were no significant differences between baseline and post-training evaluations on depression scores. The average score of usability evaluation was 75.56, which corresponds to good. Conclusion : Even though the results showed no statistically significant findings in cognitive function and depression after the virtual reality-based complex cognitive training intervention, this pilot study proposed the possibility of utilizing the virtual reality program as a tool that provides active learning opportunities for the elderly and helps improve their cognitive function through multi-sensory components. Also, the findings of this study suggested a positive reevaluation of the elderly's digital access capabilities while reducing the digital divide. A virtual reality-based complex cognitive training program improved the social network of the elderly. We expect that it will expand in size and help with their social participation of the elderly.