• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.279-285
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• 2012

Most national critical key infrastructure, such like electricity, nuclear power plant, and petroleum is run on SCADA (Supervisory Control And Data Acquisition) system as the closed network type. These systems have treated the open protocols like TCP/IP, and the commercial operating system, which due to gradually increasing dependence on IT(Information Technology) is a trend. Recently, concerns have been raised about the possibility of these facilities being attacked by cyber terrorists, hacking, or viruses. In this paper, the method to minimize threats and vulnerabilities is proposed, with the virtual honeynet system architecture and the attack detection algorithm, which can detect the unknown attack patterns of Zero-Day Attack are reviewed.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.92-98
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• 2010

Virtual ground modeling is one of key topic for real-time vehicle dynamic simulation. This paper discusses about the virtual 3D road modeling process using parametric surface concept. General road data is a type of lumped position vector so interpolation process is required to compute contact of internal surface. The parametric surface has continuity and linearity within boundaries and functions are very simple to find out contact point. In this paper, the parametric surface formula is adopted to road modeling to calculate road hight. Position indexing method is proposed to reduce memory size and resource possession, and a simple mathematical method for contact patch searching is also proposed. The developed road process program is tested in dynamic driving simulation on off-road. Conclusively, the new virtual road program shows high performance of road hight computation in vast field of off-road simulation.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.1
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• pp.50-58
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• 2003

Recently we have built a VR(Virtual Reality) theater in Kyongju, Korea, which combines the advantages of VR and IMAX theater. The VR theater provides a virtual environment for several hundreds of people at the same time. The VR theater can be characterized by a single shared screen and by multiple inputs from several hundreds of people. In this case, multi-user interaction is different from that of networked VR systems and must be reconsidered. This paper defines the multi-user interaction in such a VR theater as Audience Interaction, and discusses key issues for the implementation of the Audience Interaction. This paper also presents a real implementation example in the Kyongju VR theater.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.120-128
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• 2022

While online social interactions have been more prevalent with the increased popularity of Metaverse platforms, little has been studied the effects of facial expressions in virtual reality (VR), which is known to play a key role in social contexts. To understand the importance of presenting facial expressions of a virtual avatar under different contexts, we conducted a user study with 24 participants where they were asked to have a conversation and play a charades game with an avatar with and without facial expressions. The results show that participants tend to gaze at the face region for the majority of the time when having a conversation or trying to guess emotion-related keywords when playing charades regardless of the presence of facial expressions. Yet, we confirmed that participants prefer to see facial expressions in virtual reality as well as in real-world scenarios as it helps them to better understand the contexts and to have more immersive and focused experiences.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.3
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• pp.497-505
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• 2015

Existing Wi-Fi networks require users to follow network settings of the AP (Access Point), resulting in inconveniences for users, and the password of the AP is shared by all users connected to the AP, causing security information leaks as time goes by. We propose, in this work, a personalized secure Wi-Fi network, in which each user is assigned her own virtual Wi-Fi network. One virtual Wi-Fi per user makes the user-centric network configuration possible. A user sets a pair of her own SSID and password on her device a priori, and the AP publishes its public key in a suitable way. The AP also maintains an open Wi-Fi channel, to which users can connect anytime. On user's request, the user device sends a connection request message containing a pair of SSID and password encrypted with the AP's public key. Receiving the connection request message, the AP instantiates a new virtual AP secured with the pair of SSID and password, which is dedicated to that single user device. This virtual network is securer because the password is not shared among users. It is more convenient because the network adapts itself to the user device. Experiments show that these advantages are obtained with negligible degradation in the throughput performance.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.837-844
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• 2018

Recently, the cloud technology has made dynamical network changes by enabling the construction of a logical network without building a physical network. Despite recent research on the cloud, it is necessary to study security functions for the identification of fake virtual network functions and the encryption of communication between entities. Because the VNFs are open to subscribers and able to implement service directly, which can make them an attack target. In this paper, we propose a virtual public key infrastructure mechanism that detects a fake VNFs and guarantees data security through mutual authentication between VNFs. To evaluate the virtual PKI, we built a management and orchestration environment to test the performance of authentication and key generation for data security. And we test the detection of a distributed denial of service by using several AI algorithms to enhance the security in NFV.

• Journal of Internet Computing and Services
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• v.5 no.6
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• pp.45-58
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• 2004

This paper consists of two parts, One is the ECC( GF(2/sup m/)) algorithm to improve the security strength and the processing time of SSL VPN and the other is the WLCAPT algorithm instead of LSNAT for the security strength of virtual server. In general when corporates use SSL protocol in order to build VPN, they use RSA algorithm with the problem of security and processing time about authentication and confidentiality, In this paper, a shared public key is generated with ECSPK which uses ECC( GF(2/sup m/)) algorithm to improve the security and processing time instead of RSA In addition, WLCAPT algorithm proposed in this paper is applied to virtual server which resides in the server side and then after NAT translation, the actual server of headquarter is securely communicated with it.

• Industrial Engineering and Management Systems
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• v.10 no.2
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• pp.109-114
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• 2011

The number of small and medium enterprises (SMEs), especially those involved with research and development (R&D) programs and employed virtual teams to create the greatest competitive advantage from limited labor are increasing. Global and localized virtual R&D teams are believed to have high potential for the growth of SMEs. Due to the fast-growing complexity of new products coupled with new emerging opportunities of virtual teams, a collaborative approach is believed to be the future trend. This research explores the effectiveness of virtuality in SMEs' virtual R&D teams. Online questionnaires were emailed to Malaysian manufacturing SMEs and 74 usable questionnaires were received, representing a 20.8 percent return rate. In order to avoid biases which may result from pre-suggested answers, a series of open-ended questions were retrieved from the experts. This study was focused on analyzing an open-ended question, whereby four main themes were extracted from the experts' recommendations regarding the effectiveness of virtual teams for the growth and performance of SMEs. The findings of this study would be useful to product design managers of SMEs in order to realize the key advantages and significance of virtual R&D teams during the new product development (NPD) process. This is turn, leads to increased effectiveness in new product development's procedure.

• Journal of Korean Physical Therapy Science
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• v.24 no.1
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• pp.59-68
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• 2017

Purpose : The aims of this study was to conduct a systematic literature review with meta-analysis to investigate the effect of virtual reality based rehabilitation program on balance of patient with stroke in Korean studies. Method : The studies for analysis were searched in electronic databases(Research Information Sharing Service; RISS, Korean Studies Information Service; KISS, DBpia, e-articles, National Assembly Library). The key words for search were 'virtual reality', 'stroke', and 'balance' and only randomized controlled trials and clinical controlled trials were included. Of 40 studies identified in the search, 20 studies met the criteria of this study and included in this meta-analysis. Result : The results were as follows: 1) The overall effect size of virtual reality based rehabilitation program was 0.557(95% critical interval; 0.340~0.774). 2) In the analysis of sub-categorical variables, effect size was as follows; the commercial game type(0.621) > virtual environment type(0.335); the dynamic balance measurement(0.750) > static balance measurement(0.226); randomized controlled trial(0.653) > clinical controlled trial(0.275); and thesis type(0.706) > article of journal type(0.339). 3) In the analysis of sub-continuous variables, as time of program(per session) increased, the balance increased(p<0.05). Conclusion : The results of this study showed that virtual reality based rehabilitation program moderately improves the balance of stroke patient. Further studies are recommended to investigate the effect of sub-variables related to virtual reality programs on motor functions of patient with stroke.

• Korean Journal of Computational Design and Engineering
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• v.1 no.3
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• pp.203-214
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• 1996

An information sharing system, namely World Design View, is developed for browsing product design data on the World Wide Web environment. For the last few years information sharing has been rapidly emerging as an important research issue in the areas of concurrent engineering, product data management, virtual manufacturing, and so on. Since we are mainly concerned with product development, the key information that needs be communicated and shared is product data. The developed system puts the major advantages of STEP, OODB, and VRML together. The STEP standard provides a consistent data exchange format and application interfaces among different CAD/CAM systems. OODB is efficient and effective in dealing with complex data structures often found in engineering applications. Virtual worlds for 3-D product models can be created by VRML which is networked via the global Internet and hyperlinked with WWW. The World Design View system can support for members of virtual design teams, possibly distributed all over the world, to share 3-D shape information quickly and easily.