• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.517-526
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• 2006

In order to achieve high capacity and reliable link quality in wireless communication, the significant efforts should be concentrated on mitigating interference between cells. To solve the interference problem, the newly introduced concept of a Distributed Wireless Communication System (DWCS) can provide the capability of joint control of the signals at multiple cells. This paper proposes a new concept of virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. The proposed system manages two kinds of virtual cell. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The proposed system constructs DVC by using antenna selection method. Also, for multi-user high-rate data transmission, the proposed system introduces multiple antenna technology to get a spatial and temporal diversity gam and exploits space-Time Trellis Codes known as STTC to increase a spectral efficiency.

• The Journal of Korean Academic Society of Nursing Education
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• v.26 no.2
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• pp.198-207
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• 2020

Purpose: The purpose of this study was to explore the meaning of nursing students' experiences in virtual simulation practice. Methods: The participants were six nursing students who have experience in a virtual simulation. Data were collected from August to September 2019 through a focus group interview. Giorgi's phenomenological method was used for analysis. Results: The study results revealed 3 constituents and 6 sub-constituents that are essential for nursing student's experiences in a virtual simulation. The three constituents were: "Chaos in the virtual reality", "The process of adjusting to chaos", and "Becoming an independent nurse in a safe virtual reality". Conclusion: Based on the results of this study, the following suggestions are made. Results suggest the development of virtual simulations in Korean, the use of simulations as a group activity first, and the use of simulation between lecture and practice or in the regular curriculum. The results of the study can be used as primary data for providing virtual simulation in nursing education.

• The Journal of Information Systems
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• v.31 no.2
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• pp.19-43
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• 2022

Purpose Due to the COVID-19 pandemic, many companies are building virtual workplaces based on virtual reality technology. Through this study, we intend to identify the trend of convergence and convergence research between virtual reality technology and work space, and suggest future promising fields based on this. Design/methodology/approach For this purpose, 12,250 bibliographic data of research papers related to Virtual Reality (VR) and Workplace were collected from Scopus from 1982 to 2021. The bibliographic data of the collected papers were analyzed using Text Mining and Pathfinder Network, Parallel Neighbor Clustering, Nearest Neighbor Centrality, and Triangle Betweenness Centrality. Through this, the relationship between keywords by period was identified, and network analysis and visualization work were performed for virtual reality-based workplace research. Findings Through this study, it is expected that the main keyword knowledge structure flow of virtual reality-based workplace convergence research can be identified, and the relationship between keywords can be identified to provide a major measure for designing directions in subsequent studies.

• Journal of Korean Academy of Rural Health Nursing
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• v.18 no.1
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• pp.49-57
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• 2023

Purpose: This study was conducted to confirm the usability of virtual reality-based anatomy education programs for nursing college students and to identify factors that affect their usability. Methods: Data were collected from 143 nursing college students in Gyeonggi-do using a structured questionnaire from May to June 2022. The data analysis was analyzed using real numbers, percentages, means and standard deviation, ANOVA, Scheff's test, Pearson's correlation, and multiple regression using the SPSS/WIN 23.0 program. Results: The subject's usability was 4.26 points (out of 5). The variable that has the greatest influence on the usability of virtual reality-based anatomy education programs is perceived innovation (β=.370, p<.001), followed by perceived pleasure (β=.295, p=.001), perceived ease (β=.253, p<.001), smartphone usage time per day (β=.102, p=.031). These variables explained 70.6% of the usability of virtual reality-based anatomy education programs. Conclusion: The results of this study can be utilized as basic data for a virtual reality-based anatomy education program that will be developed and applied to nursing students in the future.

• The Journal of Korean Academic Society of Nursing Education
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• v.29 no.4
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• pp.339-351
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• 2023

Purpose: The purpose of this study is to identify the educational needs of virtual reality simulations that can be applied to novice nurses during the waiting period before starting work in a hospital. Methods: A convergent mixed methods was used. The survey data were collected from 230 novice nurses, and a focus group interview was conducted with 6 new nurses. The data were collected from November 2022 to January 2023. Descriptive statistics, a frequency analysis, independent t-test, and an Importance-Performance Analysis were performed using SPSS 24.0. Results: Appropriate topics for virtual reality simulation education were indicated to be medications and intravenous injections, which are high priority topics in quantitative and qualitative research. The novice nurses wanted group activity training three to four times a week for two weeks before beginning work in a hospital. They also wanted an immersive virtual reality system based on a real hospital environment. Conclusion: Based on the above results, this study provides basic data for the development of a virtual reality simulation education that can improve the adaptation of novice nurses to clinical practice. A strategy was suggested to utilize the waiting time before beginning work in a hospital as educational time.

• Fashion & Textile Research Journal
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• v.17 no.2
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• pp.265-277
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• 2015

The aim of this study was to successfully reflect human body changes on the transformation of the virtual body within 3D virtual fitting spaces. For this purpose, existing problems of shape transformation of the virtual body were analyzed and regression equations which provides useful basic data for transformation of the virtual body that can be applied usefully to the 3D virtual fitting system was developed. Necessary data for the analyses were body measurement and 3D scan data of women with average physical form between the ages of 40 through 49. The reason that we used human body changes of the female subjects in their forties was based on the recognition that fundamental female body changes start to occur from age of forty. Body shapes were largely divided into 3 groups according to obesity which was found to be the biggest factor of shape change. Seven factors were extracted based on factor analysis of 47 body measurement categories and regression equations were created to extract specific measurements for each BMI group based on these seven factors. The major contribution of this paper can be summarized as follows. First, the regression equations to extract specific measurements based on the 7 representative variables remediated existing problem of virtual bodies as it increased the number of body shape transformation areas. Second, the regression equations helped to overcome the problem of current failing to reflecting changes in body cross-section shape based on simple girth measurements based on analysis of cross-section distances.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.139-152
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• 2021

Simulations enable virtually experiencing rare events as well as analytically analyzing such events. Defense modeling and simulation research and develops the virtual and the constructive simulations to support these utilizations. These virtual and constructive(VC) simulations can interoperate to simultaneously virtual combat experience as well as evaluations on tactics and intelligence of combat entities. Moreover, recently, for artificial intelligence researches, it is necessary to retrieve human behavior data to proceed the imitation learning and the inverse reinforcement learning. The presented work illustrates a case study of VC interoperations in the aircombat scenario, and the work analyze the collected human behavior data from the VC interoperations. Through this case study, we discuss how to build the VC simulation in the aircombat area and how to utilize the collected human behavior data.

• Journal of the Korean Society of Earth Science Education
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• v.15 no.1
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• pp.47-61
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• 2022

In this study, We developed VR (Virtual Reality) geological resources based on the Geo Big Data of the Big Data platform that provided by the Korea Institute of Geoscience and Mineral Material (KIGAM). So students selected the theme of lessons by using these resources and we operated Remote classes using the materials that developed as to Virtual Reality. Therefore, the geological theme maps provided by the Geo Big Data Open Platform were reconstructed and produced materials were created for Study about Real Korean geological outcrops grounded in Virtual Reality. And Topographic information data was used to produce class materials for Remote classes. Twenty students were selected by Random sampling, and data were collected by conducting a survey including interviews to confirm the change in students' perception of remote classes in virtual reality geological data development and the effect of the classes, so data were analyzed through inductive categorization. The results of this study are as follows. First, students showed positive responses in terms of interest, utilization, and knowledge utilization as taking remote classes for developing geological data in virtual reality geological data. This is the result of showing the adaptability of diverse and flexible learning getting away from a fixed framework by motivating and encouraging students and inducing cooperation for communication. Second, students recognized distance education in the development of Virtual Reality geological data as 'Realistic hands-on learning process', 'Immersive learning process by motivation', and 'Learning process of acquiring knowledge in the field of earth science'.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.26-35
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• 2019

By operating servers, storage, and networking devices, Data centers consume a lot of power such as cooling facilities, air conditioning facilities, and emergency power facilities. In the United States, The power consumed by data centers accounted for 1.8% of total power consumption in 2004. The data center industry has evolved to a large scale, and the number of large hyper scale data centers is expected to grow in the future. However, as a result of examining the server share of the data center, There is a problem where the server is not used effectively such that the average occupancy rate is only about 15% to 20%. To solve this problem, we propose a Virtual Machine Reallocation research using virtual machine migration function. In this paper, we use meta-heuristic for effective virtual machine reallocation. The virtual machine reallocation problem with the goal of maximizing the idle server was designed and solved through experiments. This study aims to reducing the idle rate of data center servers and reducing power consumption simultaneously by solving problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.7
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• pp.3558-3577
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• 2017

In 2D-to-3D video conversion process, the virtual left and right view can be generated from 2D video and its corresponding depth map by depth image based rendering (DIBR). The depth map plays an important role in conversion system, so the copyright protection for depth map is necessary. However, the provided virtual views may be distributed illegally and the depth map does not directly expose to viewers. In previous works, the copyright information embedded into the depth map cannot be extracted from virtual views after the DIBR process. In this paper, a new copyright protection scheme for the depth map is proposed, in which the copyright information can be detected from the virtual views even without the depth map. The experimental results have shown that the proposed method has a good robustness against JPEG attacks, filtering and noise.