• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.65-70
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• 2005

Recently, Grid is embossed as a new issue according to the need of cooperation related to distributed resources, data sharing, Interaction and so on. It focuses on sharing of large scale resources, high-performance, applications of new paradigms, which improved more than established distributed computing. Because of the environmental specificity distributed geographically and dynamic, the most important problem in grid environment is to share and to allocate distributed grid resources. This paper proposes supply-driven strategies model that is applicable for resource management in grid environment and presents a optimal resource allocation algorithm based on resource demands. Supply-driven strategies model can offer efficient resource management by transaction allocation based on user demand and provider strategy. This paper implements the supply-driven strategies model on the DEVS modeling and simulation environment and shows the efficiency and excellency of this model by comparing with established models.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.41-56
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• 2005

Product recommender system is one of the most popular techniques for customer relationship management. In addition, collaborative filtering (CF) has been known to be one of the most successful recommendation techniques in product recommender systems. However, CF has some limitations such as sparsity and scalability problems. This study proposes hybrid cluster analysis and case-based reasoning (CBR) to address these problems. CBR may relieve the sparsity problem because it recommends products using customer profile and transaction data, but it may still give rise to scalability problem. Thus, this study uses cluster analysis to reduce search space prior to CBR for scalability Problem. For cluster analysis, this study employs hybrid genetic and K-Means algorithms to avoid possibility of convergence in local minima of typical cluster analyses. This study also develops a Web-based prototype system to test the superiority of the proposed model.

• Journal of Information Technology Applications and Management
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• v.13 no.2
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• pp.115-126
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• 2006

Recently, flash memories are one of best media to support portable computer's storages in mobile computing environment. We propose a new transaction recovery scheme for a flash memory database environment which is based on a flash media file system. We improved traditional shadow paging schemes by reusing old data pages which are supposed to be invalidated in the course of writing a new data page in the flash file system environment. In order to reuse these data pages, we exploit deferred cleaning list structure in our flash memory shadow paging (FMSP) scheme. FMSP scheme removes the additional storage overhead for keeping shadow pages and minimizes the I/O performance degradation caused by data page distribution phenomena of traditional shadow paging schemes. We also propose a simulation model to show the performance of FMSP. Based on the results of the performance evaluation, we conclude that FMSP outperforms the traditional scheme.

• Journal of Information Technology Applications and Management
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• v.12 no.3
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• pp.97-109
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• 2005

The internet and wireless communication technologies are creating ubiquitous environments in which various services are expected anytime and anywhere. Many hardware facilities have been developed and system structures are suggested for mobile services to realize a ubiquitous computing environment with appropriate quality. But these applications are not designed in the consideration of the general capabilities to perform user's wireless and mobile communication/transaction. Consequently, different needs from users are not sufficiently satisfied yet. In this study, we suggest structure of the emerging network system for mobile commerce that provides users with seamless and ubiquitous environments using location information which exploit context-aware technology.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.4
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• pp.199-204
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• 2005

In an electricity market with an imperfect competition, participants make plans of bidding and transaction strategies to maximize their own profits. The market price and the quantity are concerned with the operation reserve as well as the bidding system and demand curves in an electricity market. This paper presents a market model combined by an energy market and an operating reserve market. The competition of the generation producers in the combined market is formulated as a gaming of selecting bid parameters such as intersections and slopes in bid functions. The Nash Equilibrium(NE) is analyzed by using a hi-level optimization; maximization of Social Welfare(SW) and maximization of the producers' profits.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.174-182
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• 2002

This paper presents a comprehensive study on reducing commutation torque ripples generated in brushless DC motor drives with only a single do-link current sensor provided. In such drives, commutation torque ripple suppression techniques that are practically effective in low speed as well as high speed regions are scarcely found. The commutation compensation technique proposed here is based on a strategy that the current slopes of the incoming and the outgoing phases during the commutation interval can be equalized by a proper duty-ratio control. Being directly linked with deadbeat current control scheme, the proposed control method accomplishes suppression of the spikes and dips superimposed on the current and torque responses during the commutation intervals of the inverter. Effectiveness of the proposed control method is verified through simulations and experiments.

• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.447-448
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• 2018

기업경영에 있어서의 빅데이터 활용이라는 측면에서 해외 기업 간의 거래정보를 확보하고 이를 기반으로 밸류체인 네트워크를 구축하여 국내 기업들이 활용하도록 하는 것은 국내 기업의 대외 경쟁력을 강화하는 데 큰 도움을 줄 수 있을 것이다. 해외 기업정보 DB를 제공하는 글로벌 신용평가 기관들의 거래정보 서비스 제공사례를 파악하고 이를 국내 밸류체인 네트워크 시스템에 적용할 수 있는 전략을 제시하고자 하였다.

• Journal of Distribution Science
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• v.8 no.1
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• pp.13-19
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• 2010

Segmentation, targeting, and positioning are marketing tools used by a company to gain competitive advantage in the market. For an accurate segmentation, various statistics models or datamining techniques are used. Especially, datamining techniques are introduced in the beginning of the 1980s and solved several marketing problems effectively. In this paper, we research about datamining technique for segmentation and analyze customer's transaction data of Department Store using Decision Tree Analysis, one of the dataming technique. After that, we discuss effects and advantages of segmentation using Decision Tree.

• Journal of Information Technology Applications and Management
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• v.26 no.1
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• pp.65-75
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• 2019

As the use of semantic web based on XML increases in the field of data management, a lot of studies to extract useful information from the data stored in ontology have been tried based on association rule mining. Ontology data is advantageous in that data can be freely expressed because it has a flexible and scalable structure unlike a conventional database having a predefined structure. On the contrary, it is difficult to find frequent patterns in a uniformized analysis method. The goal of this study is to provide a basis for extracting useful knowledge from ontology by searching for frequently occurring subgraph patterns by applying transaction-based graph mining techniques to ontology schema graph data and instance graph data constituting ontology. In order to overcome the structural limitations of the existing ontology mining, the frequent pattern search methodology in this study uses the methodology used in graph mining to apply the frequent pattern in the graph data structure to the ontology by applying iterative node chunking method. Our suggested methodology will play an important role in knowledge extraction.

• Journal of Korea Technology Innovation Society
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• v.13 no.2
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• pp.379-398
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• 2010

Online technology markets are expected to provide technology suppliers with opportunities of external technology exploitation by reducing the transaction costs caused from technology transactions. This study empirically analyzes the characteristics of patents provided to the online technology market in order to identify the influences of the existence of online technology market on the patent exploitation strategy of technology suppliers. A sample of patent database is drawn from the National Technology Bank which was established as a public online market for technology. Main findings are that the propensity of patents offered to the online marketplace is higher in the cases where the patents are obsolescent, are non-core, and that consist of more claims and inventors. Through the findings of this study the existence of online technology market is identified to enable the external exploitation of firms" non-used technologies.