• ETRI Journal
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• 제43권1호
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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.

• 재무관리연구
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• 제26권1호
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• pp.165-188
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• 2009

본 연구는 개별 자산의 수익률 분포에 대한 가정 없이 평균-VaR 기준에서의 프론티어 포트폴리오를 구하고, 수익률 분포의 고차 적률에 대한 투자자의 선호가 반영된 최적 포트폴리오를 선택하는 방법을 제시하였다. 프론티어 포트폴리오를 구하기 위해 수익률 분포에 대한 가정이 필요하지 않은 그리드와 랭크 방법을 제시하였고 최적 포트폴리오를 선택하기 위해 수익률 분포의 4차 적률까지 고려된 효용함수를 사용하였다. 제시한 방법론을 실제 자료에 적용해 보기위해 모건 스탠리에서 제공하는 선진국 지수, 개발도상국 지수, KOSPI 지수의 주별 수익률 자료를 사용하였다. 평균-VaR 기준과 평균-분산 기준에서의 프론티어 포트폴리오를 구하고 각 기준에서의 최적 포트폴리오를 선택해 서로 비교하였다. 표준편차의 차이뿐만 아니라 효용함수의 수준과 주별 기대수익률로 표현되는 확실성 등가의 차이를 살펴봄으로써 두 기준 간의 경제적 의미 차이에 대해서도 살펴보았다. 또한 부트스트래핑을 이용한 역사적 시뮬레이션의 방법을 사용해 두 기준 간 발생한 차이가 통계적으로 유의한 지를 본 연구에서 적용한 자료에서는 평균-VaR 기준의 투자자가 평균-분산 기준의 투자자에 비해 더 큰 표준편차를 지닌 최적 포트폴리오를 선택하고 위험 회피도가 큰 투자자일수록 평균-VaR 기준에서의 효용이 크고 확실성 등가도 더 크게 나타나는 경향이 나타났다. 그러나 두 기준 간 발생한 차이가 통계적으로 유의하지 않게 나타나 표준편차의 차이와 경제적인 의미 차이가 크지 않다는 사실을 확인하였다.

• 한국군사과학기술학회지
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• 제8권4호
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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.

• 한국CDE학회논문집
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• 제3권4호
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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.

• 대한산업공학회지
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• 제31권2호
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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.

• 한국컴퓨터정보학회논문지
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• 제22권4호
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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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• 제14권2호
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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.

• 대한안전경영과학회지
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• 제1권1호
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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.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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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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• 제26권2호
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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.