• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.05a
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• pp.262-265
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• 2007

Metallic sandwich plates constructed of two face sheets and low relative density cores have lightweight characteristics and various static and dynamic load bearing functions. To predict the formability and performance of these structured materials, a computationally efficient FE-analysis method incorporating virtual equivalent projected model has been newly introduced for analysis of metallic sandwich plates. Two dimensional models using the projected shapes of 3D structures have the same equivalent elastic-plastic properties with original geometries including anisotropic stiffness, yield strength and linear hardening function. The projected shapes and virtual properties of the virtual equivalent projected model have been estimated analytically with the same equivalent properties and face buckling strength of 3D pyramidal truss core.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.1
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• pp.19-45
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• 2010

Virtual Communities, which are formed on the Internet, are expected to serve the needs of members for e-collaboration, e-communication, information and knowledge sharing. The executives of organizations should consider virtual community as a new innovation or knowledge pool since members share knowledge. However, many virtual community have failed due to members' low willingness to engage and furthermore to share knowledge with other members. Thus, there is a need to understand and foster the determinants of members' sense of belonging behavior in virtual community. This study develops an integrated model designed to investigate and explain the relationships between contextual factors, personal perceptions of virtual community, usability, trust and sense of belonging in using a certain virtual community. Empirical data was collected from 201 and tested using structural equation modeling (SEM) to verify the fit of the hypothetical model. The results show that the perceived usability and community trust of members significantly influences sense of belonging in using the virtual community, and information quality, system quality, familiarity on the virtual community are significantly influence the usability but not reputation. And I confirmed that perceived shared vision and responsiveness play the role of determinants in making the member's trust, perceived risk influence the making community trust in directly. The results of the study can be used to identify the motivation underlying members' sense of belonging in a certain virtual community by investigating the impacts of contextual factors and personal perceptions on virtual community, the integrated model better explains behavior than other proposed models. This study might help executives of virtual communities and organizations to manage and promote these determinants of sense of belonging to stimulate members' willingness to engage the community and futhermore enhance their virtual community loyalty.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1698-1701
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• 2006

In this research, fractal approach is applied to the realization of a virtual enterprise. Virtual enterprise is a temporarily built organization to cope with new business opportunity. It is composed of diverse business partners such as suppliers, manufacturers, customers, and service providers in value chains. Therefore, communication and interoperability problems between heterogeneous participants are one of the main concerns in developing collaboration models of a virtual enterprise. Fractal-based reference model can be a solution for this problem. The term 'fractal' is used to represent a participant of the value chains. There are many advantages when participants try to embody fractal-based collaboration model such as; (1) no restriction of inner configuration, (2) guarantee of autonomy, (3) easy implementation of interfaces, etc. Fractals are self-similar, however, this does not mean that they should have same configuration. In this paper, a fractal-based collaboration model for a virtual enterprise is proposed and described with (1) a formal formulation of fractal concept, (2) functional requirements and interfaces, and (3) a goal model as a driving force of the virtual enterprise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.6 no.6
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• pp.547-554
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• 2005

Virtual Laboratory is the new concept in the field of Control & Measurement as network technology development, it is used in many university and institute nowadays. It is possible to control and measure the instrument in anywhere, anytime by the use of Virtual Laboratory and we can raise the efficiency of experiment. In this paper, we review the concept and necessity of Virtual Laboratory at first and discuss about how we can implement Virtual Laboratory. Then we design framework of Client-Server based Virtual Laboratory fur operating of remote instrument through network, and finally we suggest system model of Virtual Laboratory capable of controlling & monitoring of instrument.

• Journal of Information Processing Systems
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• v.16 no.2
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• pp.460-477
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• 2020

As one of the most significant challenges in the virtual data center, the virtual data center embedding has attracted extensive attention from researchers. The existing research works mainly focus on how to design algorithms to increase operating revenue. However, they ignore the energy consumption issue of the physical data center in virtual data center embedding. In this paper, we focus on studying the energy-aware virtual data center embedding problem. Specifically, we first propose an energy consumption model. It includes the energy consumption models of the virtual machine node and the virtual switch node, aiming to quantitatively measure the energy consumption in virtual data center embedding. Based on such a model, we propose two algorithms regarding virtual data center embedding: one is heuristic, and the other is based on particle swarm optimization. The second algorithm provides a better solution to virtual data center embedding by leveraging the evolution process of particle swarm optimization. Finally, experiment results show that our proposed algorithms can effectively save energy while guaranteeing the embedding success rate.

• Journal of Distribution Science
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• v.17 no.3
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• pp.85-95
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• 2019

Purpose - The existing marketing studies using Social Network Analysis have assumed that network structure variables are time-invariant. However, a node's network position can fluctuate considerably over time and the node's network structure can be changed dynamically. Hence, if such a dynamic structural network characteristics are not specified for virtual goods purchase model, estimated parameters can be biased. In this paper, by comparing a time-invariant network structure specification model(base model) and time-varying network specification model(proposed model), the authors intend to prove whether the proposed model is superior to the base model. In addition, the authors also intend to investigate whether coefficients of network structure variables are random over time. Research design, data, and methodology - The data of this study are obtained from a Korean social network provider. The authors construct a monthly panel data by calculating the raw data. To fit the panel data, the authors derive random effects panel tobit model and multi-level mixed effects model. Results - First, the proposed model is better than that of the base model in terms of performance. Second, except for constraint, multi-level mixed effects models with random coefficient of every network structure variable(in-degree, out-degree, in-closeness centrality, out-closeness centrality, clustering coefficient) perform better than not random coefficient specification model. Conclusion - The size and importance of virtual goods market has been dramatically increasing. Notwithstanding such a strategic importance of virtual goods, there is little research on social influential factors which impact the intention of virtual good purchase. Even studies which investigated social influence factors have assumed that social network structure variables are time-invariant. However, the authors show that network structure variables are time-variant and coefficients of network structure variables are random over time. Thus, virtual goods purchase model with dynamic network structure variables performs better than that with static network structure model. Hence, if marketing practitioners intend to use social influences to sell virtual goods in social media, they had better consider time-varying social influences of network members. In addition, this study can be also differentiated from other related researches using survey data in that this study deals with actual field data.

• Asia pacific journal of information systems
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• v.18 no.2
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• pp.73-94
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• 2008

When individuals collaborated in virtual settings, communication is medicated through a variety of communication technologies, and is associated not only with communication effectiveness but also with socio-emotional interactions among group members. In this regards, scholars have examined how technology-mediated communication systems can be designed and used to facilitated communication interaction. However, the empirical results of the previous studies have revealed inconsistencies in the effects of communication media on users' behavioral or attitudinal responses, and on their viable effectiveness in organizations. Some studies claim that computer-mediated communication(CMC) is task-oriented but not suitable for emotional expression since it hinders close interpersonal interaction. On the other hand, some studies argue that individuals are able to develop interpersonal relationships more effectively in a CMC environment than in an FtF-environment. Due to the different perspectives, a theoretical gap exists, and it leads to the inconsistent research findings. The purpose of this paper is to combine the two different perspectives into single unified model, thereby providing a more realistic and comprehensive understanding about virtual collaboration. The present study here sought to answers the following questions with organizational communication perspective: What are the major components of virtual collaboration? What factors affect the performance of virtual collaboration? And what kind of managerial efforts should organization make in order to facilitate CMC media effectiveness in virtual collaboration? Although there is a certain belief that new media, namely technology-mediated communication support would create new opportunities, the problem of "how" or "why" has been an important question that is still not fully addressed. In this regards, we collectively reexamined previous literatures with major issues which are still controversial and integrated various theoretical activity within computer-mediated communication domain: task-oriented approach, socio-emotional approach, and evolutionary psychological approach. Our first contribution is to develop a framework for virtual collaboration by combining two different perspectives into a single unified model, providing a more realistic and comprehensive understanding. The second main contribution is the joint modeling of both social presence and cognitive effort, and the effects on two distinct but important communication outcomes(i.e., take performance and relational development). We tested the research hypotheses which were developed based on the various CMC theories using data gathered through a self-administered mail survey of 127 individuals of 69 virtual workgroups. The proposed model was supported, providing preliminary evidence that the tension between two opposite view should be integrated. The results show that the individual's psychological processes(social presence and cognitive effort) in a virtual environment significantly mediated the effect of CMC inputs (media richness, user adaptation, and shared contest) on the CMC outputs (task performance and relational development). Furthermore, this study shows that the lack of perceived media richness of CMC media can be complemented by user adaptation and shared context. Based on the results, we discuss how communication system should be designed and implemented so as to promote virtual interaction as well as how a virtual workgroup should be composed to complement the lack of media richness. A virtual collaboration using CMC media may create new value by overcoming the logistical constraints. On the other hand, it may also generate various managerial risks such as communicational depersonalization, process dissatisfaction, and low cohesion. Therefore, this study suggests that organization managers should carefully choose the CMC mediums and monitor individual member's cognitive and affective psychological processes during virtual collaboration to reduce potential risks in virtual collaboration.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.6
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• pp.1109-1123
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• 2017

This study analyzed a somatotype of teenager's that was suitable to improve the reality of a virtual model size. We analyzed 843 teenagers 12-18 years old from the 6th Size Korea data. First, factor analysis was done for abstracting new criteria and dividing the somatotype; subsequently, we selected the waist height proportion to stature (body proportion) and drop (torso shape). Next, the cluster analysis was done with these criteria; subsequently, 5 body proportion types and 7 torso shapes were distinguished. A virtual model size for 4 somatotype with more than 50 persons was also designed by a regression analysis that constituted sizes for each factor. The designed model size was compared with body size as well as with Clo's virtual model size. The research model showed a high similarity in sizes with body as well as improved reality over the Clo model that presented size problems such as low waist height, bigger bust, and smaller thigh circumference than the real body.

• Journal of the Korean Home Economics Association
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• v.44 no.7 s.221
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• pp.153-162
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• 2006

This study was attempted to investigate the possibilities of fitness evaluation of virtual model using 3D clothes modeling software. For the purpose, two one-piece dresses were made with two kinds of patterns using Qualoth program, and then each dress was fitted to a real model and a virtual model, and the results were compared and discussed. The result of this study was as follows. First, the fitness evaluation of real model showed a significant difference only at a little difference in figures (1-2.5cm) of the pattern, while any significant difference in appearance was not found in case of a virtual model fitted a dress made out of a pattern with the same difference in figures. Second, items to evaluate a difference in patterns using 3D clothes modeling software were shoulder line, the distance between shoulder points, armhole line, ease of armscye depth, and overall appearance. Because all the items fall under design lines which make up outer lines of a cloth, it can be said that the Qualoth program is good for representing design, rather than exposing a small difference in patterns.

• Fashion & Textile Research Journal
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• v.17 no.2
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• pp.278-286
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• 2015

Fashion industry has tried to adopt the virtual garment technology to reduce the time and effort spent on sample creation. For garment manufacturers to adopt the virtual garment technology as an alternative to sample creation, 3D avatars that meet the needs of each brand should be developed. Virtual garment softwares that are available in the market provide avatars with standardized body models and allow to modify the size by manually entering size specifications. This study proposed a methodology to develop size specifications for 3D avatars as well as brand-customized production sizes. For this, a man's fashion brand which is using virtual garment technology is selected. And the Size Korea database is used to develop size specification based on the customers' body shape. This study developed regression equations on body size specifications, which in turn proposed a regression model to proportionately change size specifications of 3D fitting-models. Based on the each body size calculated by the regression model, a standard model is created, and the skeleton-skin algorithm is applied to the regression model to obtain the results of size changes. Then, the 3D model sizes are tested for size changes as well as measured, which verifies that the regression model reflects body size changes.