• Journal of Digital Contents Society
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• v.15 no.5
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• pp.595-602
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• 2014

Cloud computing is already well known paradigm that a support computing resource flexible and scalable to users as the want in distributed computing environment. Actually, cloud computing can be implemented and provided by virtualization technology. Also, various products are released or under development. In this paper, we built the teaching practice system using cloud computing and evaluated practical environment which constructed over a virtual machine. Virtualization-based cloud computing provides optimized computing resources, as well as easy to manage practical resource and result. Therefore, we can save the time for configuration of practice environment. In the view of faculty, they can easily handle the practice result. Also, those practice condition reuse comfortably and apply to various configuration simply. And then we can increase capabilities and availabilities of limited resources. Additionally, we measure the performance requirements for educational applications through evaluation of virtual-based teaching practical system in advance.

• The Journal of Information Systems
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• v.23 no.1
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• pp.225-246
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• 2014

With the recent establishment of a ubiquitous environment and the paradigm shift to a smart society, the use of mobile devices, such as smart phones and tablet PCs, has become widespread. Thus, the trend is gradually shifting from using Web-based Instant Messenger to using Mobile-based Instant Messenger. Mobile Instant Messenger refers to a service that allows instant messaging as well as data sending and receiving between individuals with exclusive application programs(mobile Apps), which can be used in portable devices-such as smart phones-with wireless Internet access. Korea's portal sites, telecommunication companies, and even big companies have all rushed into the MIM market to join the competition. The reason so many companies are showing interest in the MIM business is because it is rising as a core platform to substitute portal sites in the mobile society, and MIM is perceived as the best means to attract and secure users. The intention to reuse or use continually was considered an important factor in maintaining a dominant position amidst such fierce competition, and consequently, most research thus far has reflected such thought. However, the frequent or long-term use of a system alone cannot indicate the definite success of the system, nor guarantee its dominant position in the market. On the contrary, MIM dependence, which goes beyond simple repetitive use and indicates a state where users actually or emotionally depend on a specific system, can better explain the user action. However, not much research has been conducted on dependence. The research results showed that lively message, concise message, message responsiveness, and social belonging significantly affected perceived usefulness. Message responsiveness, Link, and social belonging significantly affected flow. Flow significantly affected MIM dependence, and perceived usefulness did not affect MIM dependence. This study has proven that lively message, concise message, message responsiveness, Link, social belonging and perceived usefulness are important antecedents and mediating factors of MIM dependence. Moreover, this study is significant in that it explains the overall process of MIM dependence, and expands on the variety and scope of research that can be applied to MIM-related studies.

• Aerospace Engineering and Technology
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• v.10 no.2
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• pp.56-64
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• 2011

In this paper, the characteristics of LCL set-up parameters for the satellite load distribution are analyzed under the electrical system environment, implemented the LCL circuits and evaluated the performance and its behaviour. Recently, it is implemented the load distribution circuit by latching current limiter(LCL) rather than conventional fuse and relay for the protection of the satellite power system from a fault load. The LCL circuit is composed of the electrical components, not mechanical parts with the fuse and relay. When detected the over current on a fault load, it is activated to maintain the trip-off level for set-up time and then cut-off the load power by the active control. It is more flexible and provided a chance to reuse of the load in case of temporarily event, but the fuse and relay can't be used again after activating due to the physical disconnection. However, for implementation of LCL circuit, it should be carefully considered the behavior of the LCL circuit under the worst electrical system environment and applied it to define the set-up parameters related with over-current inhibition.

• Journal of Intelligence and Information Systems
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• v.3 no.2
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• pp.1-9
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• 1997

These papers propose an evolutionary algorithm for re-using output of waste fuel of light water reactor system in nuclear power plants. Evolutionary algorithm is useful for optimization of the large space problem. The wastes contain several re-useable elements, and they should be carefully selected and blended to satisfy requirements as input material to the heavy water nuclear reactor system. This problem belongs to a NP-hard like the 0/1 Knapsack problem. Two evolutionary strategies are used as a, pp.oximation algorithms in the highly constrained combinatorial optimization problem. One is the traditional strategy, using random operator with evaluation function, and the other is heuristic based search that uses the vector operator reducing between goal and current status. We also show the method, which performs the feasible teat and solution evaluation by using the vectorized data in problem. Finally, We compare the simulation results of using random operator and vector operator for such combinatorial optimization problems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.3A
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• pp.235-243
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• 2009

In this paper, we investigate the cognitive and cooperative communication scheme to improve the spectral efficiency in multiuser OFDMA systems using wireless relays. First, we propose the frame structure in which the efficient frequency reuse scheme with the cognitive technique is performed to increase the system throughput. And in the case where the THP (Tomlinson-Harashima preceding) is used for the elimination of interference from the relay, we derive the effective signal to noise ratio of the link largely affected by the channel quantization error. From the system level simulation results, it is shown that the proposed cognitive and cooperative communication scheme increases the overall system performance including the feedback overhead.

• The KIPS Transactions:PartD
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• v.8D no.6
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• pp.789-798
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• 2001

ITS (Intelligent Transport Systems) is comprised of a number of advanced technologies, including information processing, communications, control, and electronics. Joining these technologies to the transportation system will save lives more safely, save time, and save money more efficiently. The National ITS Architecture provides a common framework for planning, defining, and integrating intelligent transportation systems. Most ITS projects are being designed and implemented in accordance with the National ITS Architecture, a reference framework that spans all of standards activities. Recently, as software technology is rapidly improved and stabilized, there are some needs to reuse pre-developed and powerful ITS technology. ITS standardization based on components and open interfaces becomes a way to solve these reusability of current ITS technology. This paper focuses on how could we design and implement the ITS component based on the National ITS Architecture. Furthermore, design and analysis of UML (Unified Modeling Language) was made through the ATIS (Advanced Traveller Information System) component development task and this UML methodology is expected to provide a standardized model for newly developed ITS components.

• The Transactions of the Korea Information Processing Society
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• v.7 no.10
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• pp.3064-3074
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• 2000

Lately computing environment is changing into integrating open system Some corporations and research institutions are still using old codes and not dealing with the rapid canging environment actively. Also several software developers have difficulties with the problems of productivity and translating old codes. This paper proposes Integration Object Management Model to deal with the rapid changing environment effectively and to improe productivity about new software development. The model is divided into three layers the first layer classifies and displays information to users, the second layer controls function, the integrationand management layer, and the last layer manages data, the object management stroage later. So it designs and implenments F77/J++ Generator system(FORTRAN77/Java code generator) for Integrated Object Management Model. The generator helps to translate old codes into new codes in redesigning the business and promoting productivity. In consists of nine-stage strategies using reengineering. This might support agterward protolyping in maximizing the reuse of software, which is advanlage to the integrationof the system and in pro,oting its productivity.

• Journal of KIISE:Software and Applications
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• v.29 no.1_2
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• pp.10-19
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• 2002

In searching and locating a collection of components on the Web, users require a Web browser. Since the Web libraries tend to grow rapidly, there needs to be an effective way to organize and manage such large libraries. Traditional Web-based library(retrieval) systems provide various classification scheme and retrieval services to store and retrieve components. However, these systems do not include invaluable services, for example, enabling users to grasp the overall contents of the library at the beginning of retrieval. This paper discusses a Web-based library system, which provides the efficient management of object-oriented components and a set of services beyond simple component store and retrieval. These services consist of component comprehension through a reverse engineering process, automated summary extraction, and comprehension-based retrieval. Also, The performance of an automated cluster-based classification scheme adopted on the system is evaluated and compared with the cluster-based classification scheme adopted on the system is evaluated and compared with the performance of two other systems using traditional classification scheme.

• Journal of Korea Multimedia Society
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• v.10 no.5
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• pp.642-651
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• 2007

Recently, digital convergence, whose core demand is OSMU (One Sourse Multi Use),has been the main topic in e-learning domain and industry. However, the existing web learning content and the new resource developed toprovide contents to different learning environment must be processed to adapt the new learning settings, which causes the cost and time problem, So in this paper we design and implement a Java based SCORM content transcoding system which can transcode the SCORM-based learning content into MHP-based DiTV content in order to adapt t-learning environment using DiTV, which is closer to our real life. Using this system which has ability of inter-operation, reuse, highly-use, the problem mentioned above can be solved well. Moreover, it is possible for a learner who is not familiar with computer to study using DiTV instead of PC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.649-652
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• 2009

Now Broadcasting system of TV has been developed from analogue to digital we call that IPTV(Internet Protocol Television) or DCATV(Digital Cable Television). But, The characteristics of digital broadcasting is the high-quality contents of easily and almost no damage piracy, and Copyright loss is increasing by Internet, P2P(Peer to Peer) and personal path. Nevertheless user's permissions that recorded and reuse of broadcasting can't restraint, And Training Materials etc. use of fair program needs to be separated from illegality. In this paper using a digital certificate permit the use of stored program to authorized user and user of fair purpose, And illegal distribution of restriction design and implement a distribution system.