• ETRI Journal
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• v.43 no.1
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• pp.53-63
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• 2021

Cloud computing has drastically reduced the price of computing resources through the use of virtualized resources that are shared among users. However, the established large cloud data centers have a large carbon footprint owing to their excessive power consumption. Inefficiency in resource utilization and power consumption results in the low fiscal gain of service providers. Therefore, data centers should adopt an effective resource-management approach. In this paper, we present a novel load-balancing framework with the objective of minimizing the operational cost of data centers through improved resource utilization. The framework utilizes a modified genetic algorithm for realizing the optimal allocation of virtual machines (VMs) over physical machines. The experimental results demonstrate that the proposed framework improves the resource utilization by up to 45.21%, 84.49%, 119.93%, and 113.96% over a recent and three other standard heuristics-based VM placement approaches.

• The Korean Journal of Financial Management
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• v.26 no.1
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• pp.165-188
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• 2009

This paper has suggested the methodology for the frontier portfolios and the optimal portfolio under the mean-VaR framework, not assuming the normal distribution and considering the investor's preferences for the higher moments of return distributions. It suggested the grid and rank approach which did not need an assumption about return distributions to find the frontier portfolios. And the optimal portfolio was selected using the utility function that considered the 3rd and the 4th moments. For the application of the methodology, weekly returns of the developed countries index, the emerging market index and the KOSPI index were used. After the frontier portfolios of the mean-variance framework and the mean-VaR framework were selected, the optimal portfolios of each framework were compared. This application compared not only the difference of the standard deviation but also the difference of the utility level and the certainty equivalent expressed by weekly expected returns. In order to verify statistical significances about the differences between the mean-VaR and the mean-variance, this paper presented the statistics which were obtained by the historical simulation method using the bootstrapping. The results showed that an investor under the mean-VaR framework had a tendency to select the optimal portfolio which has bigger standard deviation, comparing to an investor under the mean-variance framework. In addition, the more risk averse an investor is, the bigger utility level and certainty equivalent he achieves under the mean-VaR framework. However, the difference between the two frameworks were not significant in statistical as well as economic criterion.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.58-67
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• 2005

To overcome limitations of test scope, schedule and cost, M&S(Modeling & Simulation) technique has been applied for T&E(Test and Evaluation) of the state-of-art weapon systems. This paper proposes an air defense simulation software framework to reduce both redundancy an[1 programming errors in system simulator. The proposed framework consists of a 'model' and a 'middleware' The 'middleware' is a reliable communication service layer that supports not only HLA(High Level Architecture) which is an international standard in M&S but also TCP/IP, UDP and etc. The main role of 'model' is to schedule and to run the real-time distributed simulation. The proposed framework has been applied to M-SAM(Middle range Surface to Air Missile) system simulator. The proposed framework's scheduling and communication performance results are satisfactory and were measured by hardwired NTP(Network Timer Protocol) time-stamp with GPS(Global Positioning System) timer for better precision.

• Korean Journal of Computational Design and Engineering
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• v.3 no.4
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• pp.283-292
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• 1998

The engineering process including design, analysis/evaluation and manufacturing activities is becoming one of the key issues to embody a concurrent engineering concept. This paper proposes a framework to integrated the complicated engineering design and manufacturing processes under the concurrent engineering environment. The framework offers the following facilities: (1) to represent the complicated engineering process (2) to coordinate design activities and execute the process in a distributed environment (3) to support a communication among the related engineers. The engineering processes is depicted using process flow graphs that consist in tasks and the corresponding input and output data. The engineering activities in the defined processes can be executed in a distributed environment through process controller of the framework. Engineers can communicate to suggest their opinions and to exchange product information in the framework. We have conformed the CORBA standard to integrate various distributed engineering the and communicate among them, and used a Java to support the platform independent environment on the Internet. Since the proposed framework an be a formal approach to integrate the engineering processes by providing formalism, parallelism, reusability, and flexibility, it can be effectively applied to embody the concurrent engineering concept in a distributed environment.

• Journal of Korean Institute of Industrial Engineers
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• v.31 no.2
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• pp.152-163
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• 2005

The focus of enterprise collaboration of supply chain management, has changed from integrating and exchanging business information to integrating and managing business processes between business partners. However, the collaboration is difficult due to the inherent complexity such as diverse business processes and dynamic business environments. To settle these problems, a reference model based enterprise architecture framework for the collaboration of supply chains is proposed in this paper. The supply chain collaboration framework is composed of three reference models capturing the different views of supply chain collaboration: supply process reference model, service component reference model, and technology and standard reference model. As the framework adapts the OMG's metadata architecture, the processes in the supply chain can be extended and integrated with other value chains, such as design chains, when it is necessary. Using the proposed framework, business managers can rapidly integrate and manage their business processes with their suppliers and customers.

• Journal of the Korea Society of Computer and Information
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• v.22 no.4
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• pp.51-58
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• 2017

Research on the Development of EPUB SCP(Secure Content Protection) Technical Specification and International Standardization has been carried out as a R&D project granted by the Korea Copyright Commission since 2014. The research aims to build a standard framework for the EPUB DRM(Digital Rights Management) based on the Readium LCP(Licensed Content Protection) and KS EPUB DRM specifications, to develop element technologies for the framework, and to standardize it as an IDPF(International Digital Publishing Forum) industrial standard. One of the essential features of the EPUB DRM developed though this study is to support the lending model of the digital library. This paper introduces LSD(License Status Document) specification which is a DRM license management protocol for the digital library lending process, and also represents a model which can automatically test the implemented entities of the LSD specification, test scenarios and test materials.

• Journal of Information Technology Applications and Management
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• v.14 no.2
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• pp.117-127
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• 2007

Using an exchange standard, we can design an open architecture for the interchange of decision models and data. XML (eXtensible Markup Language) provides a general framework for creating such a standard. Although XML -based model representation languages such as OOSML were proposed, they are partly limited in expression capability, flexibility, generality, etc. This paper proposes a new method for expressing and sharing decision models and data based on XBRL (eXtensible Business Reporting Language), which is a XML language specialized in business reporting. We have developed a XBRL taxonomy for decision models with the concepts and relationships of a representative modeling framework, SM (Structured Modeling). The method allows for expressing data as well as decision models in a consistent and flexible manner. Diverse dependencies between components of SM models can also be affluently expressed.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.217-230
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• 1999

The prevalent phenomenon in the high technology market shows market-determined do facto standard is preferred to de jure standard determined by formal organization. The purpose of the study is to provide a framework to empirically examine the relationship between network externalities and switching costs from the consumer's point of view Key findings of the study are ： First, physical compatibility and upgradability are positively related to the network externalities. Second, conceptual compatibility and expertise are negatively related to the switching costs. Third, the network externalities and the switching costs are positively related to the continuous usage decision. Finally, the network externalities are positively related to the switching costs. The followings are major implications of the study. First, network externalities and bandwagon effects have different causal relationship respectively. Second, contrast to Weiss and Heide's (1993) study, the study suggests multiple dimensions of compatibility, Third, physical compatibility and upgradability increase switching costs through network externalities as the moderator.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.301-305
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• 2002

Bioinformatics can beexplained as the science of developing algorithms, applicatiou tools, and computer databases and so on, for the purpose of supporting and enhancing biological research. Bioinformatic information systems (BIS) typically handle large data sets and the amount of the data goes up exponentially. Another impediment to easy extraction and retrieval of genomic data in BIS is the need to access different sites for similar information. Recently. there has been some attempts to integrate bioinformatics data in the World Wide Web (WWW) among the bioinformatics community by the internet computing technology. However, the work to integrate bioinformatics data on a universal platform has some problems because of the lack of standard, terminologies, semantics, and ontologies about bioinformatics. In this paper, an XML-based BIS architecture is proposed as an integrated BIS framework. The XML and related technologies allow the creation of meaningful information tags to exchange data between various databases as a standard format, and to create more simple interfaces. This integrated BIS framework has bioinformatic architectural components which is used in the Corporate Information Factory (CIF) method.

• ETRI Journal
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• v.26 no.2
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• pp.112-121
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• 2004

Digital Multimedia Broadcasting (DMB) is an upcoming standard in Korea used to provide mobile multimedia broadcasting service based on the Eureka-147 Digital Audio Broadcasting (DAB) system. The current dominant multimedia coding standard, MPEG-4, is foreseen to play an important role in forthcoming DMB services. However, the current approaches for transporting MPEG-4 content over DMB networks are not optimized. To address this issue we propose a novel MPEG-4 stream multiplexer, called M4SMux, which provides better stream multiplexing and delivery over DMB networks. M4SMux features an MPEG-4 elementary-stream interleaving mechanism that reduces the multiplexing overhead and a multiplex configuration mechanism that utilizes M4SLinkTable for easy content access. In addition, we propose an error correction method which enhances transport efficiency.