• Journal of Computing Science and Engineering
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• 제7권4호
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• pp.285-299
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• 2013

To enable hard real-time systems to take advantage of multicore processors, it is crucial to obtain the worst-case execution time (WCET) for programs running on multicore processors. However, this is challenging and complicated due to the inter-thread interferences from the shared resources in a multicore processor. Recent research used the combined cache conflict graph (CCCG) to model and compute the worst-case inter-thread interferences on a shared L2 cache in a multicore processor, which is called the CCCG-based approach in this paper. Although it can compute the WCET safely and accurately, its computational complexity is exponential and prohibitive for a large number of cores. In this paper, we propose three counter-based approaches to significantly reduce the complexity of the multicore WCET analysis, while achieving absolute safety with tightness close to the CCCG-based approach. The basic counter-based approach simply counts the worst-case number of cache line blocks mapped to a cache set of a shared L2 cache from all the concurrent threads, and compares it with the associativity of the cache set to compute the worst-case cache behavior. The enhanced counter-based approach uses techniques to enhance the accuracy of calculating the counters. The hybrid counter-based approach combines the enhanced counter-based approach and the CCCG-based approach to further improve the tightness of analysis without significantly increasing the complexity. Our experiments on a 4-core processor indicate that the enhanced counter-based approach overestimates the WCET by 14% on average compared to the CCCG-based approach, while its averaged running time is less than 1/380 that of the CCCG-based approach. The hybrid approach reduces the overestimation to only 2.65%, while its running time is less than 1/150 that of the CCCG-based approach on average.

• 경영과학
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• 제16권2호
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• pp.13-32
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• 1999

Concurrent Engineering is one of the information-based product development approach. Yet, the method of organizing the project team for the concurrent engineering is not clear. This study focuses on deriving a method to organize an information-based project team. The model consists of 4 layers : IT infrastructure, organization of the information-based project team, operation of the project team, an organization culture. Based on an analysis of new product development case, this study attempts to verify the model and to suggest more effective way of organization design and management for new product development.

• Journal of Information Technology Applications and Management
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• 제16권3호
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• pp.113-124
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• 2009

How can action learning program promote organizational learning performance and especially project based team performance in Web-based small and medium-sized enterprises (SMEs)? This article discusses the association between project based team in action learning program and the performance of Web-based SME to be learning organization. In the case of ALPACO, action learning program that promote employee communication behavior, knowledge sharing, and organizational learning are found to be positively associated with the project based team performance and organizational learning, The results indicate that action learning program in SMEs indeed associated with greater knowledge sharing, learning communication skills and changing organizational culture. Learning organization can be, in turn, positively developed by project based team through action learning program for creating competitive advantage, Also, this study offers further support for the practical perspective on learning organization performance. The evidence from this case study suggests that the project team in action learning program playa significant role in team performance and the development of learning organization of the firm. Therefore, in the future, Web-based SMEs should consider making investments in action learning program that encourage project team's effective management in decision making, knowledge sharing, and organizational learning.

• 한국환경과학회지
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• 제25권2호
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• pp.311-322
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• 2016

This study reduced and built Street Canyons created by skyscrapers in order to verify effect of Street Canyons by green wall within the city centre and analysed influence factors on temperature reduction according to applicative types of green wall in the lab. Applicative types were divided into three types such as non- greening type(Case A), one-side greening type(Case B), both side greening type(Case C). The result of analysis of each types showed that average temperature of Case B and Case C is respectively $1.0^{\circ}C$ and $1.7^{\circ}C$ lower than Case A. The result of analysis of WBGT was that the highest temperature was given by Case A($40.2^{\circ}C$) and second one was from Case B($39.8^{\circ}C$) and third one was from ($39.1^{\circ}C$) and in UTCI Case A records the highest temperature of $34.7^{\circ}C$ and Case B provided the second highest temperature of $33.9^{\circ}C$ and Case B gave the lowest temperature of $32.7^{\circ}C$. In PMV the highest temperature of 2.65 was from Case B and second one of 2.61 was from Case A and third one of 2.54 was from Case C. Duncan analysis of each types based on solar radiation and thermal comfort generated that there was analytical significance between Case A and Case B and Case B in terms of each types of average temperature reduction. The significance of thermal comfort in WBGT, MRT, PMV showed non-significance but, In UTCI it was analysed that there was significance between Case C and Case A.

• 한국정보처리학회논문지
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• 제6권1호
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• pp.96-106
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• 1999

사례기반 추론은 이전에 해결된 문제에 대한 해를 재사용 함으로써 새로운 문제를 해결한다. 그러나 과거의 사례와 새로운 문제 사이에는 차이가 있다. 이러한 문제점을 해결하기 위해서 사례기반 추론 시스템은 이전 사례의 해를 새로운 상황에 맞게 적응 시켜야 한다. 최근의 사례기반 추론 시스템에서, 사례 적응은 시스템 개발자에 의해 손으로 코딩된 규칙을 사용하는 규칙기반 방법을 이용한다. 따라서 시스템 설계자는 과거의 전통적인 전문가 시스템 설계에서 발견되는 지식획득의 병목방법을 제안하였다. 적응 지식을 학습하기 위해 사례 베이스의 사례들을 비교하는 방법을 사용하였다. 본 논문에서 제안한 방법은 여행 가격 결정을 위한 영역에서 실험하였다. 실험 결과 사례 추출만을 지원하는 시스템보다 해에 대한 정확도가 향상되었음을 확인할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.796-799
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• 2005

지난 10년간 소프트웨어 공학 분야의 연구개발 프로젝트에서 object oriented(OO) 기술이 생산성과 재사용성 향상에 중대하게 공헌 할 수 있었던 것을 보여주었다. 본 논문은 이들 가운데 두 가지 중요한 연구영역인 CASE 도구와 컴포넌트에 기반한 기술에 대한 이슈에 연관되어 있다. 본 논문은 CASE 도구에 컴포넌트 기반의 기술을 적용하는 예로써, COM/OLE 기술에 기반한 복합문서지원 기능이 있는 OO CASE 도구인, OODesigner를 개발하였다. 복합문서지원 기능이 있는 OODesigner가 윈도우 시스템의 다른 응용소프트웨어와 함께 상호운용 가능함으로써, 다른 CASE 도구보다 더욱 강력한 문서의 이용 환경을 제공할 수 있다는 것을 보여준다. OODesigner는 단지 UML 다이어그램을 모형화 할 수 있을 뿐만 아니라, OLE 서버와 컨테이너들과 함께 여러가지 다양한 종류의 문서를 협동하여 만들 수도 있으므로, 이 CASE 도구로 강력하고 일관된 문서화에 이용할 수 있다.

• 한국정보시스템학회지:정보시스템연구
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• 제8권1호
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• pp.27-44
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• 1999

Case-Based Reasoning(CBR) offers a new approach for developing knowledge based systems. CBR has several research issues which can be divided into two categories : (1) static issues and (2) dynamic issues. The static issues are related to case representation scheme and case data model, that is, focus on casebase which is a repository of cases. The dynamic issues, on the other hand, are related to case retrieval procedure and problem solving process, i.e. case adaptation phase. This research is forcused on retrieval procedure Traditional query processing accepts precisely specified queries and only provides exact answers, thus requiring users to fully understand the problem domain and the casebase schema, but returning limited or even null information if the exact answer is not available. To remedy such a restriction, extending the classical notion of query answering to approximate query answering(AQA) has been explored. AQA can be achieved by neighborhood query answering or associative query answering. In this paper, neighborhood query answering technique is used for AQA. To reinforce the CBR process, a new retrieval procedure(cooperative CBR) using neighborhood query answering is proposed. An neighborhood query answering relaxes a query scope to enlarge the search range, or relaxes an answer scope to include additional information. Computer Aided Process Planning(CAPP) is selected as cooperative CBR application domain for test. CAPP is an essential key for achieving CIM. It is the bridge between CAD and CAM and translates the design information into manufacturing instructions. As a result of the test, it is approved that the problem solving ability of cooperative CBR is improved by relaxation technique.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.178-184
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• 2003

Case-based reasoning (CBR) often shows significant promise for improving effectiveness of complex and unstructured decision making. Consequently, it has been applied to various problem-solving areas including manufacturing, finance and marketing. However, the design of appropriate case indexing and retrieval mechanisms to improve the performance of CBR is still challenging issue. Most of previous studies to improve the effectiveness for CBR have focused on the similarity function or optimization of case features and their weights. However, according to some of prior researches, finding the optimal k parameter for k-nearest neighbor (k-NN) is also crucial to improve the performance of CBR system. Nonetheless, there have been few attempts which have tried to optimize the number of neighbors, especially using artificial intelligence (AI) techniques. In this study, we introduce a genetic algorithm (GA) to optimize the number of neighbors to combine. This study applies the new model to the real-world case provided by an online shopping mall in Korea. Experimental results show that a GA-optimized k-NN approach outperforms other AI techniques for purchasing behavior forecasting.

• 한국정보시스템학회지:정보시스템연구
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• 제18권3호
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• pp.231-249
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• 2009

Recently, plant construction industries are enjoying a favorable business climate centering around developing countries and oil producing countries rich in oil money. This paper proposes a methodology of implementing case-based reasoning(CBR) system for managing knowledge like lessons learned and various documents accumulated in performing power plant construction projects which are receiving a lot of order from foreign countries such as the Middle East, etc. Our methodology is consisted of 10 steps : user requirement gathering, information modeling, case modeling, case base design, similarity function design, user interface design, case base building, CBR module development, user interface implementation, integration test. Also, to illustrate the effectiveness of proposed methodology, the real CBR system is implemented for the plant business division of 'H' company which has international competitiveness in the field of plant construction industry. At present, the implemented CBR system is successfully utilizing as storing, sharing, and reusing knowledge which is accumulated in performing power plant construction projects in the target enterprise.

• 산업경영시스템학회지
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• 제22권51호
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• pp.129-138
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• 1999

The aim of this research is the development of an automated fixture planning system for prismatic parts using the case-based reasoning (CBR). CBR is the problem solving paradigm that uses the similarity between a new problem and old cases to solve the new problem. This research uses CBR for the fixture planning. A case is composed with the information of the part, the components of fixture and the method of fixing for the part. The basic procedure is the retrieval and adaptation for the case, and this research presents the method of retrieval that selects most similar case to the new situation. The retrieval-step is divided into an index matching and an aggregated matching. The adaptation is accomplished by the modification, which transforms the selected case to the solution of the situation of the input part by the specified CBR algorithm. The components of fixture and the method of fixing are determined for a new part by the procedure.