• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권10호
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• pp.1841-1861
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• 2011

The advance in Service-Oriented Architecture (SOA) and web services has led to the development of new types of a system in which heterogeneous service components can connect and compose to solve a complex business problem. In the SOA, even though these service components are valid in their functionality, there is a need to test their behaviors when those services are composited. In recent years, WS-BPEL has received a wide acceptance as a means of integrating distributed service components. To test the composite service, the existing testing techniques have been focused on the functional features based on the WS-BPEL process. However as SOA approach is applying to real-time software development, the performance of composite service becomes one of important issues. This paper proposes a technique to the performance testing of a composite service with WS-BPEL extension which combined with the concept of aspect. Our WS-BPEL extension has been made towards annotating aspect component which is measuring the response time of the composite service. This paper also explains the procedure of performance testing with on-line transaction system. Our technique can apply to choose an adequate component in service composition with considering the performance among several candidate web service components.

• 산업공학
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• 제19권3호
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• pp.190-201
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• 2006

With the rapid growth in the demand and supply of web service, the search for superior services has become a prominent issue. Furthermore, much emphasis and attention are being placed on composite web services, where individual services are combined together to form a single workflow to satisfy the demand of the customers. In today's era of excessive expansion of web services, this study intends to propose the execution plan architecture for composite web services to accomplish the following three goals. The first goal is to derive a feasible plan which maximize user satisfaction for composite web services by implementing an execution plan architecture that reflects the Quality of Service criteria. Secondly, this study also aims at analyzing and selecting the indexes that adequately reflects its quality and its nonfunctional property. Finally, this study intends to apply the concept of constraint satisfaction problem and heuristics to reduce the execution duration of the process.

• 대한산업공학회지
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• 제35권1호
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• pp.51-57
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• 2009

There are a variety of users and devices in a context-aware computing environment. In this environment, the service provided to a user may be the composition of diverse services rather than one independent service. Before user's devices provide the composite service to the user, they should perceive user's needs by gathering related information segments from other surrounding devices and/or sensors. We consider a context-aware computing environment providing composite and adapted service to users and propose an information processing model that characterizes the device where the collected data should be processed through services and/or applications. Based on this model, we provide an analytical tool to obtain some performance measures of the context-aware computing environment.

• 한국도로학회논문집
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• 제16권6호
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• pp.1-8
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• 2014

PURPOSES : Analysis and design of asphalt concrete (AC) and continuously reinforced concrete (CRC) composite pavements. METHODS : In this study, the service life of the AC/CRC composite pavements was determined based on the probabilistic method in the mechanistic-empirical pavement design guide(MEPDG). Typical pavement design was provided with respect to heavy truck traffic volume of highways. RESULTS : The service life of the composite pavements based on IRI was shorter than that based on rutting at lower traffic volume, but this trend was switched at higher traffic volume. CONCLUSIONS : It is concluded that the main distress affecting the service life of the composite pavements was longitudinal roughness and rutting. Roughness became lower, but rut depth became greater as the stiffness of the CRC increased.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.139-142
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• 2003

As composite materials are gaining wide acceptance in aircraft structure, repair of damaged composite is becoming an important issue. The issues in composite repair include high cost, material interchangeability, water ingression, and structural integrity. To address these problems, researchers have studied on the composite repair in various aspects. In this paper, an Internet-based advisory service (called Repair Advisory Service, RAS) for composite repair is proposed to increase efficiency for repair process. In the RAS system the web browser is used as its user interface, which provides easy access to the service. The RAS server provides web-based tools for failure prediction, Structural Repair Manual (SRM), automated prepreg cutting process, material properties, inventory and knowledge base. The computer codes implemented for repair design estimate the tensile failure and shear failure of repaired structures. The prediction of failure is based on the maximum strain criterion for tensile failure while elastic-perfect plastic shear failure model is applied for interfacial failure. The OEM's SRM is provided in the PDF format for viewing and searching by web browsers instead of looking up paper version SRM. The knowledge base in this site offers a room to share and distribute ideas, memos, publications, or suggestions from the repair engineers. The fabrication tool of RAS reads repair geometry from engineers then generates a CNC toolpath to cut prepreg patches. The RAS service is open to public and available at http://nano.gsnu.ac.kr/. Broad feedback from field technicians and engineers is welcome to improve the usefulness of RAS.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권8호
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• pp.2743-2762
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• 2014

Promoted by cloud technology and new websites, plenty and variety of Web services are emerging in the Internet. Meanwhile some Web services become outdated even obsolete due to new versions, and a normal phenomenon is that some services work well only with other services of older versions. These laggard or improper services are lowering the performance of the composite service they involved in. In addition, using current technology to identify proper semantic services for a composite service is time-consuming and inaccurate. Thus, we proposed a clustering method and a recommendation method to deal with these problems. Clustering technology is used to classify semantic services according to their topics, functionality and other aspects from plenty of services. Recommendation technology is used to predict the possible preference of a composite service, and recommend possible component services to the composite service according to the history information of invocations and similar composite services. The experiments show that our clustering method with the help of Ontology and TF/IDF technology is more accurate than others, and our recommendation method has less average error than others in the series of missing rate.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제1권3호
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• pp.149-158
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• 2012

최근 서비스 기반의 소프트웨어 개발이 사용자의 다양한 요구를 충족시킬 수 있는 하나의 솔루션으로 부각되면서, 안정적인 서비스의 조합을 통하여 보다 큰 서비스를 제공하려는 시도가 증가하고 있다. 그러나 조합된 서비스의 개발시 고려되어야 하는 사항중의 하나는 사용자의 입장에서 서비스의 정확성과 함께 신속성을 제공해야 한다는 것이다. 왜냐하면 사용자가 서비스의 요청 과정에서 늦은 응답으로 인하여 실행 버튼을 중복적으로 클릭하는 행동을 보이기 때문이다. 본 논문에서는 조합된 서비스의 성능을 측정하기 위한 테스팅 프레임워크를 제시한다. 즉, 조합된 서비스의 실행 시간을 측정함으로써, 개발자에게 서비스의 성능을 분석할 수 있는 도구를 제공한다. 이러한 실행시간 측정을 위하여 본 연구에서는 Aspect 컴포넌트를 이용하는 타이머 서비스를 개발하여 기존 웹 서비스들과 연동할 수 있도록 하였다. 또한 몇 실험을 통하여 조합된 서비스의 성능 테스트가 가능함을 확인하였다. 제시한 프레임워크는 조합된 서비스를 구성하는 단위 서비스 중에서 가장 많은 시간이 소요되는 서비스를 식별하고 필요에 따라 다른 서비스로 대체할 수 있는 서비스 개발을 가능하게 한다.

• 한국컴퓨터정보학회논문지
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• 제14권10호
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• pp.189-197
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• 2009

웹 서비스 기술이 안정화됨에 따라 기업내 혹은 기업간 웹 서비스들을 통합한 합성된 웹 서비스의 연구가 활발히 진행되고 있다. 또한, 비기능적 속성은 다르지만 유사한 기능을제공하는 웹 서비스들의 증가로 인하여 품질관리는 중요한 이슈로 여겨지고 있다. 품질관리를 위해서는 모니터링 기능이 필요하다. 본 논문에서는 중개자를 통한 합성된 웹 서비스의 품질 모니터링 시스템의 설계를 제안한다. 이 시스템은 OWL-S를 사용하여 합성된 서비스의 프로세스를 명세하며 WS-Policy를 사용하여 다양한 요구사항인 정책(각 서비스 입력 출력값, 품질요소 및 품질요소 값 등)을 명세하여 합성된 서비스 프로세스모델에 첨부한다. 또한, 센서를 이용하여 명세한 정책과실제로 모니터링된 데이터의 값을 비교하여 불일치하면 위반사항이 발생하였음을 웹 서비스 제공자 및 사용자에게 통보함으로서 품질을 관리한다. 제안한 시스템의 검증을 위하여 여행 예약 시스템 예제를 가지고 평균 응답시간과 타임아웃 정책을 적용하여 모니터링한 결과를 보여 준다.

• 산업경영시스템학회지
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• 제35권4호
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• pp.186-193
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• 2012

Assessing service quality and satisfaction is the essential part of service science. In this study, for G2B electronic commerce service composed of information systems and human resources, a composite research model for exploring factors of service quality satisfaction is proposed. The proposed model uses SERVQUAL's five quality dimensions as independent antecedent factors and usefulness and ease-of-use of the technology acceptance model as mediating factors. A case of a G2B purchase service is empirically studied using the proposed model. The result shows that the proposed composite model is good and appropriate for explaining the characteristics of G2B services.

• Steel and Composite Structures
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• 제38권4호
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• pp.415-430
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• 2021

The effective flange width was usually introduced into elementary beam theory to consider the shear lag effect in steel-concrete composite beams. Previous studies have primarily focused on the effective width under positive moments and elastic loading, whereas it is still not clear for negative moment cases in the normal service stages. To account for this problem, this paper proposed simplified formulas for the effective flange width and reinforcement stress of composite beams under negative moments in service stages. First, a 10-degree-of-freedom (DOF) fiber beam element considering the shear lag effect and interfacial slip effect was proposed, and a computational procedure was developed in the OpenSees software. The accuracy and applicability of the proposed model were verified through comparisons with experimental results. Second, a method was proposed for determining the effective width of composite beams under negative moments based on reinforcement stress. Employing the proposed model, the simplified formulas were proposed via numerical fitting for cases under uniform loading and centralized loading at the mid-span. Finally, based on the proposed formulas, a simplified calculation method for the reinforcement stress in service stages was established. Comparisons were made between the proposed formulas and design code. The results showed that the design code method greatly underestimated the contribution of concrete under negative moments, leading to notable overestimations in the reinforcement stress and crack width.