• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.604-607
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• 2004

한국의 수자원은 연간 강수량이 세계 평균보다 1.3배나 많음에도 불구하고 높은 인구밀도와 지형적 조건, 관수시설 및 물에 대한 인식 부족으로 물 부족 현상이 현실로 다가오고 있다. 또한 많은양의 정수된 물이 송수과정에서 땅속에서 새어나가고 있다. 그러나 현재의 누수탐지 방법으로는 정확한 누수의 위치를 찾기 어렵고, 많은 비용을 투입하고 있지만 현실적인 제약사항이 많아 그 효과는 기대치에 이르지 못하고 있다. 본 논문은 TBR(Time Domain Reflectometer)을 이용한 누수탐지 기법으로 탐색한 누수위치 및 파이프 정보를 실시간으로 모니터링하여 빠른 복구를 가능하게 하고, 누수 비용을 줄일 수 있는 누수탐지 지리정보시스뎀(Geographic Information System)을 구축하였고, 누수탐지와 지리정보시스템의 모니터링 효율성을 높이기 위한 공간데이터베이스의 설계에 대하여 기술하였다. 또한 독립적인 형식으로 공간데이터베이스를 구축하여 서비스를 제공하는 기존 GIS들 사이에 다양한 종류의 지리정보를 효율적으로 활용하기 위해 OGC에서 제안한 GML(Geography Markup Language) 문서로의 변환에 관한 가능성을 검증하였다.

• Journal of Intelligence and Information Systems
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• v.14 no.1
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• pp.117-129
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• 2008

The cost-based scheduling work has been done in both the Operations Research (OR) and Artificial Intelligence (AI) literature. To deal with more realistic problems, AI-based heuristic scheduling approach with non-regular performance measures has been studied. However, there has been little research effort to develop a full inter-job cost propagation algorithm (CPA) for different jobs having multiple downstream and upstream activities. Without such a CPA, decision-making in scheduling heuristics relies upon local, incomplete cost information, resulting in poor schedule performance from the overall cost minimizing objective. For such a purpose, we need two types of CPAs : intra-job CPA and inter-job CPA. Whenever there is a change in cost information of an activity in a job in the process of scheduling, the intra-job CPA updates cost curves of other activities connected through temporal constraints within the same job. The inter-job CPA extends cost propagation into other jobs connected through precedence relationships. By utilizing the cost information provided by CPAs, we propose cost-based scheduling heuristics that attempt to minimize the total schedule cost. This paper develops inter-job CPAs that create and update cost curves of each activity in each search state, and propagate cost information throughout a whole network of temporal constraints. Also we propose various cost-based scheduling heuristics that attempt to minimize the total schedule cost by utilizing the cost propagation algorithm.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1262-1272
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• 1996

Pure functional languages have the referential transparency feature sothat all objects cannot be updated destuctively. Once an aggregated data structure such as array is updated, both the original and newly updated array must be preserved to maintain reverential transparency. Thus, it is required to develop an efficient mechanism with which can reduce the maintenance cost while maintaining referential transparency for whole data. This study is to suggest a functional array to solve the problem, and them test it. For that, the proposed mechanism was implemented on a combinator graph reduction machine. The result shows that proposed mechanism reduces traversal time for array operations. Also, updating all versions and accessing the recent version are achieved in constant time without reconstruction of updated data in execution time.

• Journal of the Korea Society of Computer and Information
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• v.8 no.1
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• pp.13-19
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• 2003

There are active researches on automated guided vehicles(AGV) generally used in flexible manufacturing system(FMS) or automated warehouse systems(AWS). Because existing AGV uses magnetic tapes, electric wire, RF or laser as guidelines, its installation and modification require a lot of money and time. The present study implemented AGV that detects paths marked with 50mm Yellow tape using a mono-color CCD camera. Because it uses color tape, it is easy and inexpensive to install and change lines. This study presented the structure of the developed AGV, the image Processing technique for detecting guidelines by ing the characteristics of color, and the result of operating AGV.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.13-21
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• 2014

The set covering problem (SCP) is one of representative combinatorial optimization problems, which is defined as the problem of covering the m-rows by a subset of the n-columns at minimal cost. This paper proposes a method utilizing Integer Programming-based Local Search (IPbLS) to solve the set covering problem. IPbLS is a kind of local search technique in which the current solution is improved by searching neighborhood solutions. Integer programming is used to generate neighborhood solution in IPbLS. The effectiveness of the proposed algorithm has been tested on OR-Library test instances. The experimental results showed that IPbLS could search for the best known solutions in all the test instances. Especially, I confirmed that IPbLS could search for better solutions than the best known solutions in four test instances.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.65-72
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• 2007

Labeling schemes which don't consider about frequent update in dynamic XML documents need relabeling process to reflect the changed label information whenever the tree of XML document is update. There is disadvantage of considerable expenses in the dynamic XML document which can occurs frequent update. To solve this problem, we suggest prime number labeling scheme that doesn't need relabeling process. However the prime number labeling scheme does not consider that it needs to update the sibling order of nodes in the tree of XML document. This update process needs much costs because the most of the tree of XML document has to be researched and rewritten. In this paper, we propose the prime number labeling scheme with sibling order value that can maintain the sibling order without researching or rewriting the tree of XML documents.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.160-162
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• 2003

Magic Square는 자원 탐색을 제공하는 P2P 프로토콜이다. 그러나 복구비용이 높고 인접한 하나 이상의 노드가 고장났을 경우에는 복구하지 못한다. 본 논문에서는 Magic Square의 복구를 위한 정보를 저장하는 복구 노드를 사용하였다. 복구 노드는 관리하는 영역 전체의 라우팅 테이블을 유지하기 때문에 노드가 고장이 나더라도 즉시 연결을 복구할 수 있다. 본 논문에서 제안하는 방법은 시스템의 성능을 떨어뜨리지 않고 모든 링크 복구와 대부분의 자원 복구를 할 수 있는 장점이 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.572-575
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• 2012

본 논문은 스테레오 시각에서 3차원 정보를 얻기 위해 변형된 Census 변환과 적응적 윈도우를 이용한 다해상도 스테레오 영상 정합 방법을 제안하고자 한다. 영역 기반 기법으로 스테레오 영상의 대응점을 찾기 위해 탐색 화소 주변 영역의 기울기를 계산하여 윈도우의 크기 및 모양을 적응적으로 결정하고, 윈도우 영역의 정합 비용 함수는 변형된 Census 변환과 AD 연산 결과의 가중합으로 구한다. 정합 과정에서 계산복잡도를 줄이기 위해 계층적 다해상도 구조를 적용하여 영상 피라미드를 만들고, 정합의 정확성을 향상시키기 위해 정합 영역에 변위 평활성과 같은 제약 조건을 적용하여 변위를 전파하는 방법을 사용한다. 실험을 통해 제안한 방법이 변위 탐색 시간을 감소시킬 뿐만 아니라 정합의 타당성이 보장됨을 확인하고자 한다.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.182-187
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• 2008

It needs to consider of turns during a path-finding on real road network. traveling on real road network, it generally takes less travel time in a more straight path than a zig-zaged path with same source and destination. In this paper, we propose $VTA^*$ algorithm that can reduce the cost of exploring despite increasing the number of turn in comparing with $TA^*$ algorithm. We have implement the proposed $VTA^*$, $TA^*$ which consider the number of turn and a traditional $A^*$ algorithm which dosen't consider the number of turn. The experimental result shows that the cost of exploring is reduced by 7.31 % comparing with $TA^*$ and the number of turn is reduced by 27.95% comparing with $A^*$ approximately.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.1
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• pp.78-89
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• 2017

This study derived the algorithm of a public transportation route search that adds safety and environmental costs according to user preference. As the means of an algorithm application and evaluation, Macro Simulation, VISUM was conducted for an analysis. The route using the subway, which is relatively low in safety and environment resistance value was preferred, and it was analyzed to select the safe and environmental route even though it detours. This study can be applicable when to verify the algorithm of route search considering safety and environment, and when introducing the algorithm of route search according to user preference in the smart-phone application in the future, it can provide users with very useful information by choosing a route as for safety and environment, and through this, the quality of user-friendly information provision can be promoted.