• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.199-214
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• 2007

Recently, there have been a lot of works trying to realize automated composition of semantic web services though application of AI planning techniques. The traditional AI planning techniques, however, have some limitations: it is not easy to represent a web service process with complex control constructs as an action or a plan; it is hardly possible to consider enough the rich information contained in domain ontologies during the planning process; it is impossible to model directly the data flow from the outputs of a web service to the inputs of another web service; it is difficult to predict and deal with uncertainty and dynamics of the environment because the plan generation phase is supposed to be separated from the plan execution phase. In order to overcome some of these limitations, this paper suggests a reactive planning approach to automated composition of semantic web services. Through some experiments using several e-commerce web services, we found that the reactive planning is an effective way to realize automated composition of semantic web services.

• Journal of KIISE:Software and Applications
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• v.32 no.9
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• pp.888-900
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• 2005

Several researches have been proposed to formalize the knowledge preconditions problem - j.e., an action or a plan is epistemically feasible. However, since the feasibility is only checked at design-time and is assumed that it will also 1)e feasible at run-time, it is not suitable in the context of Semantic Web services composition, where many agents should share the limited resources required for the execution of Web services composition. Therefore, in this paper, we formalize a transactionally executable Web services composition which enables to guarantee its atomicity. Moreover, in order to formalize the transactional executability, we propose $TL-ALCFK_{NF}$ which extends TL-ALCF with the modal operators K and A. Based on $TL-ALCFK_{NF}$, we show how to carry out the epistemic reasoning with TL-ALCF as a language to represent Semantic Web services composition.

• Journal of Korea Multimedia Society
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• v.11 no.9
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• pp.1310-1323
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• 2008

Recently, many studies on automated generation of composite Web services have been done. Most of these works compose Web services by chaining their inputs and outputs, but do not consider the functional semantics. Therefore, they may construct unsatisfied composite services against users' intention. Futhermore, they have high time-complexity since every possible combinations of available services should be considered. To resolve these problems, this paper proposes a sophisticated composition method that explicitly specifies and uses the functional semantics of Web services. Specifically, A graph model is constructed to represent the functional semantics of Web services as well as the dependency among inputs and outputs. On the graph, we search core services which provide the requested function ality and additional services which transform between I/O types of the user request and the core services. Then, composite services are built from combinations of the discovered services. The proposed method improves the semantic correctness of composite services by the functional semantics of Web services, and reduces the time complexity by combinations of functionally related services.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.04a
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• pp.1058-1061
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• 2010

시맨틱 웹 서비스 기술의 성공을 보장하기 위해서는 품질 좋은 온톨로지의 사용이 필수적이다. 하지만 온톨로지 사용의 중요성에도 불구하고 현재 웹 서비스를 위한 온톨로지는 거의 존재하지 않으며 이들의 구축도 쉬운 일이 아니다. 이러한 문제는 오늘날 웹 서비스의 확산과 발전을 가로막는 큰 저해요인이 되고 있다. 본 논문에서는 웹 서비스를 개발할 때 자동 생성되는 WSDL 문서만 가지고 항목 간 숨어있는 시맨틱 정보를 찾아내어 온톨로지를 자동 구축하고, 이를 활용한 (반)자동화된 웹 서비스 발견 및 조합 시스템을 구현하는 것이다.

• Journal of Intelligence and Information Systems
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• v.16 no.3
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• pp.15-35
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• 2010

Web service Technology has been developing rapidly as it provides a flexible application-to-application interaction mechanism. Several ongoing research efforts focus on various aspects of Web service technology, including the modeling, specification, discovery, composition and verification of Web services. The approaches advocated are often conflicting-based as they are differing expectations on the current status of Web services as well as differing models of their future evolution. One way of deciding the relative relevance of the various research directions is to look at their applicability to the currently available Web services. To this end, we conducted a survey on currently publicly available Web service repositories. Our aim is to get an idea of the number, complexity and composability of these Web services and see if this analysis provides useful information about the near-term fruitful research directions.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.105-109
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• 2008

자동차, 항공기, 철도차량, 선박 등의 제품개발에 필요한 일련의 엔지니어링 활동들을 유기적으로 연결하고 통합하기 위해서는 엔지니어링 협업(비지니스 프로세스)을 처리하기 위한 시스템이 요구된다. 엔지니어링 프로세스 협업을 구성하는 엔지니어링 서비스는 일반적인 웹 서비스와 비교할 때 상대적으로 긴 응답시간과 높은 실행비용 등에서 차별화 된다. 본 논문에서는 서비스 조합에 수치해석 특성, 서비스 크기 등의 엔지니어링 서비서의 특성들을 반영시켜 제한된 시간과 비용을 만족하는 엔지니어링 프로세스 협업을 처리할 수 있는 웹 서비스 조합 시스템을 제안하였다. 또한 서비스 조합 모델링 단계에서 QoS 기반 서비스 선택 액티비티와 서비스 조합 실행 단계에서 서비스 선택 알고리즘을 제시하였다.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.101-112
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• 2005

Recently, one of the most challenging Problems is to compose web services dynamically, that is, on demand. In particular, when a functionality that cannot be directly realized by existing services is required, existing services may be combined together to fulfill the request. This paper is to implement the dynamic composition of web services using existing workflow technologies. Workflow systems play a major role in E-businesses. However, due to the composition of web services using workflows differs from the design of traditional workflow systems, two problems need to be solved. (1) how to efficiently discover web services and (2) how to facilitate the interoperability of heterogeneous web services. In this paper, we present a matching algorithm for web service discovery and propose an approach based on the use of ontologies to facilitate the integration of web services. Finally, we have built a prototype system to illustrate how to the dynamic composition of web services are achieved.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.172-174
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• 2006

시맨틱 웹서비스 조합을 위해 인공지능 분야의 계획수립 기법을 적용하려는 연구들이 최근 늘고 있다. 하지만 전통적인 계획수립 기법이 갖는 계획작성 단계와 실행 단계가 분리되어 있기 때문에 여러가지 한계성을 나타낸다. 본 논문에서는 이의 대안으로서 동적 재연결을 지원하는 반응형 계획기 기법을 사용함으로써 제기된 문제점들을 해결하고자 하였으며, 온톨로지 처리 결과를 계획수립 과정에 반영함으로써 의미 기반의 웹서비스 조합이 이루어지도록 하였다. 그리고 이를 지원하는 시스템의 개발과 응용을 통해 반응형 계획기술이 시맨틱 웹서비스의 조합과정에서 견고하고, 유연하게 동작함을 알 수 있었다.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.145-157
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• 2009

OSGi enables services to be dynamically discovered through its service registry for fostering interactions among themselves, positioning itself as one of the most prominent SOA technologies. Web Services also provide a mature technical base of open business services being employed over the Internet and allow more value-added applications to be built up from component services. In this paper, we propose a new architecture, built on the concept of dynamic service binding, to support interbred service compositions of OSGi and Web Services. Web Services are imported into OSGi domains, and the compositions are described in WS-BPEL language. The support for crossbred compositions of OSGi services and Web Services opens up a new opportunity of a wider range of applications beyond their respective traditional target domains of home gateways in LAN environments and business applications in global Internet environments.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.39-44
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• 2005

최근 웹 서비스(Web Service)와 웹 프로세스(Web Process)는 이기종 시스템의 통합과 웹 애플리케이션 배포를 위한 대안으로 주목받고 있으며, 이에 따라 웹 서비스의 QoS(Quality of Services)의 중요성도 증가하고 있다. 본 논문에서는 웹 서비스의 QoS 분석 방법을 제안하고, QoS 중심의 웹 서비스 조합 도구인 SimQom4W (Simulation-based QoS-aware Composer for Web Services)를 소개한다. SimQom4W는 첫째, 웹 서비스와 웹 프로세스의 구성을 시각으로 기술하고, 둘째, 웹 프로세스에 대한 테스트 코드와 시뮬레이션 코드를 자동 생성하여 실행시킴으로써 QoS를 분석한다. 셋째, 다양한 QoS 요구사항을 만족하는 최적의 웹 프로세스를 선택할 수 있도록 하며, 넷째, 웹 서비스의 QoS 분석 및 평가 데이터의 보고서를 생성하여 제공한다.