• Journal of Korea Water Resources Association
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• v.43 no.9
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• pp.769-780
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• 2010

Topological and hydraulic assessments to examine whether required demand and pressure are satisfied and using these assessed results as a criteria have been general methodology for reliability assessment of water distribution systems. However, many of existing studies that used nodal pressure calculated by hydraulic assessment for reliability assessment have two major issues to be solved. The one is that demand-driven analysis was used for hydraulic assessment and the other is that serviceability was not considered for reliability assessment. In addition, all of the studies used pressure-demand analysis which is suitable to hydraulic analysis for water distribution systems under abnormal operating condition considered only available nodal demand for reliability assessment. This means that advantages which can be obtained by pressure-driven analysis are not used properly and efficiently. In this study, new methodology for reliability assessment of water distribution systems using HSPDA model and distance measure method is suggested. This methodology considers both nodal pressure and nodal available demand for reliability assessment. Suggested methodology is applied to two water distribution systems to show its applicability and application results are compared with existing study.

• Annual Conference on Human and Language Technology
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• 2010.10a
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• pp.194-196
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• 2010

휴대폰의 광범위한 보급으로 문자메시지의 사용이 급증하고 있다. 이와 동시에 사용자가 원하지 않는 광고성 스팸문자도 넘쳐나고 있다. 본 연구는 이러한 스팸문자메시지를 자동으로 판별하는 시스템을 개발하는 것이다. 우리는 기계학습방법인 지지벡터기계(Support Vector Machine)을 사용하여 시스템을 학습하였으며 자질의 선택은 카이제곱 통계량을 이용하였다. 실험결과 F1 척도로 약 95.5%의 정확률을 얻었다

• Journal of Intelligence and Information Systems
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• v.13 no.1
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• pp.91-105
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• 2007

This research suggests a recommendation system that enables bidirectional communications between the user and system using a utility range-based product recommendation algorithm in order to provide more dynamic and personalized recommendations. The main idea of the proposed algorithm is to find the utility ranges of products based on user specified preference information and calculate the similarity by using overlapping probability of two range values. Based on the probability, we determine what products are similar to each other among the products in the product list of collaborative companies. We have also developed a Web-based application system to recommend similar products to the customer. Using the system, we carry out the experiments for the performance evaluation of the procedure. The experimental study shows that the utility range-based approach is a viable solution to the similar product recommendation problems from the viewpoint of both accuracy and satisfaction rate.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.824-829
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• 2006

한정된 자원을 사용할 수 있는 게임 AI 분야에서는 시스템 자원을 적절하게 활용하여 현실감을 극대화 시키려는 노력이 중요한 이슈이며, 3D 게임에서 캐릭터들의 자연스러운 경로 탐색은 현실성을 높이는 중요한 척도 중 하나이다. 기존 연구에서는 주로 정적인 지형, 객체들을 적절하게 회피하는 경로에 대한 연구가 많이 진행되었다. 그러나 최근 널리 이용되고 있는 다중사용자가 접속하는 온라인 RPG 게임에서는 기존 방법을 그대로 적용하기에 많은 연산량이 필요한 문제점이 있다. 본 논문에서는 네비게이션 메시(Navigation Mesh) 기반으로 최적화된 A*, 그리고 밀개(Repulsors)의 방법을 통하여 동적인 환경에서 자연스러운 경로탐색을 수행하며 3D 게임에 적용 가능한 연산량을 충족하는 경로탐색 시스템을 제안하였다.

• Annual Conference of KIPS
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• 2000.04a
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• pp.680-685
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• 2000

최근 그 심각성이 커지고 있는 해킹피해를 줄이기 위한 한 방법으로 시스템에 침입한 불법적 사용을 탐지하는 연구가 활발히 진행되고 있다. 침입을 탐지하는 방법으로는 오용탐지와 비정상행위 탐지가 있는데 비정상행위 탐지를 위해서는 정보수집의 정확성, 신속성과 함께 다량의 정보들로부터 필요한 정보를 추출하고 축약하는 것이 중요하다. 본 논문에서는 감사기록 도구인 BSM으로부터 정보를 추출하고 자기조직화 신경망을 이용하여 다차원의 정보를 저차원정보로 축약.변환하는 방법에 대한 실험적인 검증을 시도하였다. 또한 BSM에서 얻을 수 있는 데이터의 유용성을 조사하기 위하여 축약된 감사자료에 의한 탐지성능을 살펴보았다. 실험결과, 시스템 호출 및 파일관련 정보의 축약이 탐지성능향상에 크게 기여하는 중요한 척도임을 알 수 있었으며 각 척도마다 탐지성능이 좋은 맵의 크기가 다름을 알 수 있었다. 이러한 축약된 정보는 여러 정상행위 모델링방법에 의해 유용하게 사용될 수 있을 것이다.

• Journal of Internet Computing and Services
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• v.9 no.5
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• pp.85-97
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• 2008

Recently, service-oriented systems have been issued by their properties of reducing software development time and effort by reusing functional service units. The reusability of services can effectively promote through loose coupling between services and loose coupling between services depends on component-based system. That is, the component-based system is designed by grouping the tightly coupled classes of the object-oriented system and the service-oriented system is designed by the component-based system. Therefore, to design the component-based system and service-oriented system efficiently, a metric to measure the coupling between classes accurately needs. In this paper, we propose a coupling metric between classes applying a structural property, a dynamic property, and the normalized value by 0-1. We prove the theoretical soundness of the proposed metric by the axioms of briand et al, and suggest the accuracy and practicality through a case study. We suggest the evaluation results of the proposed metric through a comparison with the conventional metrics.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.160-162
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• 2003

색인 파일은 정보 검색 시스템에서 중요한 구성 요소 중에 하나이다. 스테밍을 하여 색인 파일을 구성하게 되면 파일의 크기를 줄일 수 있고 재현율을 높이는데 효과적이다. 하지만, 과도한 스테밍으로 구성이론. 색인 파일은 원형에 대한 데이터 손실을 가지고 오기 때문에 너무 많은 문서가 검색되어 사용자가 문서를 찾는데 많은 시간이 소요되고 정확률도 떨어진다. 본 논문에서는 정보 검색 시스템에서 검색의 효율성을 높이기 위해 사용하는 색인 파일을 스테밍 한 것과 스테밍 하지 않은 파일로 구성하였다. 스테밍 한 색인 파일은 질의어와 문서 사이의 유사도를 계산하기 위하여 이용되며, 스테밍 하지 않은 파일은 스테밍 했을 때 검색된 문서들 중에서 데이터 손실로 인한 잘 못된 문서 순서를 재조정해 주기 위하여 이용된다. 본 논문에서는 높은 검색 효과를 제공하는 기존의 벡터 공간 모델을 검색 성능 평가 척도 중의 하나인 R-정확률을 이용하여 비교 평가하였다. 본 논문에서 제안하는 시스템이 문서 상위 100위까지에 대하여 일반 벡터 모델 보다 최고 21%의 좋은 성능을 보였다.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.91-102
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• 2002

We need a component-based system to reflect software changes in user's requirements, to implement a system at a rapid speed as well as to efficiently manage the system in a maintenance phase and to easily change software. Moreover, the component-based system has a merit in development cost. However, existing component development methodology for implement of component-based system is inefficient in object identification for component identification. Moreover, the existing component development methodology also fails to provide any method to identify system component. It merely provides procedures and methods to identify business component focused on a whole system domain. In addition, it has another problem that it considerably relies on developer's experiences and intuitions for component identification. Therefore, according to this paper, RUP (Rational Unified Process) is applied from a requirement analysis phase to an object identification phase in order to improve the inefficiency of object identification. In addition, this paper procedures and methods for system component identification, and identifies business components based on the identified system component, rather than on the whole system domain. This paper also provides and applies cohesion metric and coupling metric so as to overcome the problem that component identification depends on developer's intuitions and experiences. Accordingly, the component identification method proposed in this paper, may identify components more effectively based on facility of object identification, functional reusability of components, traceability, and independence of components.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.2
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• pp.212-218
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• 2011

The curriculum of programming education including algorithm has been recognized as a very important subject to many students majoring in natural sciences and engineering including electronic engineering and computer related departments. This study analyzed usability of the learning system of programming languages using basic algorithms so as for students to easily learn basic algorithm among the entire programming curriculum. The results show that the grade of learning achievement of experimental group using the learning system is 15 points higher than that of non-experimental group and the grade of interest, concentration, effectiveness, understanding, convenience, suitability, and attending a lecture in the next semester are 4 points or more of 5 points criterion.

• Archives of design research
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• v.17 no.4
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• pp.107-118
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• 2004

Nowadays Industrial Design appears to us as provided products in the market through only User Interface and Technical Improvement. Consumer purchasing products intend to grant the meaning for the product by mobilizing his specific feeling and experience the moment he contact products the first time. As metaphorical character shown in the product is named to the Product Language, Industrial designer shall constantly proceed the study on the exact understanding or processing method. As Objects or products using by us imply aesthetical value, it appears to be different according to the diverse condition of products be different according to the diverse condition of products to be used. In case objectivity is unsatisfactory, aesthetic character shown in the product requires new instrumental system. Product analysis applied aesthetical measure of BIRKHOFF can be applied as tool for inherent metaphorical character of product and product development. With this, Design operation shall be much easier. So Application of aesthetical measure is not only a system but a tool giving help to carry out more smooth design process.