• Journal of KIISE:Software and Applications
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• v.36 no.1
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• pp.1-9
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• 2009

In heterogeneous and distributed computing environments, with an increasing number of Web services providing similar functionalities, the reliability of Web services is a critical decision factor. To fulfill the open business model such as cooperation among enterprises, several Web services can be composed into the upper level business transaction. In Web services composition, the reliability of services is more and more critical. Though each unit Web service can be reliable, the reliability of the composed service is not guaranteed. Thus a way to efficiently assess and select composed Web services is needed. In this paper, we define new metrics for measuring the trust value of Web services, and propose an evaluation method to predict the trustworthy degree of the composed services based on the metrics. We also define a conceptual framework to support optimal Web services selection based on the proposed trust evaluation method. By selecting using the quantitative measurement rather than intuitive selection of the service user, it allows the service users to select the high reliable service meeting their quality requirements well.

• Journal of Digital Convergence
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• v.12 no.10
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• pp.291-297
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• 2014

Web service is a standardized software technology which enables interoperability for various applications regardless of operating systems and programing languages through public networks such as the internet and by web service standards. It is distributing computer services that enable a web environment by discovering and providing necessary services. However, there are drawbacks when selecting services for new web environments because current various search methods are based on performance of those services. Even when the performance of the service is improved by selecting web services based on either the service performance or when the new services are discovered, lack of resources causes the web services to get pushed back from the current service list. Therefore, in order to resolve resource allocation issues when selecting web services, this study offers the suitable services for the clients by applying improved services based on scalable information and by applying the information obtained by the clients when requested.

• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.119-133
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• 2011

With the advent of Web 2.0, the use of RESTful web services is expected to overtake that of the traditional SOAP-based web services. Recently, the growing number of RESTful web services available on the web raises the challenging issue of how to locate the desired web services. However, the existing keyword searching method is insufficient for the bad recall and the bad precision. In this paper, we propose a novel building semantic ontology method which employs both the clustering technique based on association rules and the semantic analysis technique based on patterns. From this method, we can generate ontologies automatically, reduce the burden of semantic annotations, and support more efficient web services search. We ran our experiments on the subset of 168 RESTful web services downloaded from the PregrammableWeb site. The experimental results show that our method achieves up to 35% improvement for recall performance, and up to 18% for precision performance compared to the existing keyword searching method.

• Journal of Information Technology and Architecture
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• v.10 no.2
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• pp.159-167
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• 2013

Web Services offer many benefits over other types of middleware in distributed computing. However, usage of Web Services results in large network bandwidth since Web Services use XML-based protocol which is heavier than binary protocols. Even though there have been many researches to minimize the network traffic and bandwidth usages of Web Services messages, none of them are solving problem clearly yet. In this paper, we propose a transparent proxy with cache to avoid transfer of repeated SOAP data, sent by Web Service to an application. To maintain the cache consistency, we introduce publish/subscribe paradigm using WS-Eventing between the proxy and Web Service. The implemented system based on our proposed architecture will not compromise the standards of Web Service. The evaluation of our system shows that caching SOAP messages not only reduces the network traffic but also decreases the request delays.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.406-408
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• 2002

광범위하게 이용하고 있는 웹은 기존에 텍스트나 이미지만을 제공하던 정적인 정보에서 사용자 위주의 서비스 중심으로 변화하고 있다. 웹 환경의 변화는 Web Services를 등장 시켰고 산업계에서 이미 이를 위한 표준화 작업 및 표준에 따른 Web Services 개발을 주력하고 있다. 이에 Web Services를 이용한 어플리케이션 개발이 또 다른 소프트웨어 공학적 이슈로 대두되어 그를 위안 연구가 진행 중이다. 본 논문에서는 Web Services 어플리케이션 개발을 위한 목표 지향 분석 방안을 제시하고 결론과 시멘틱 웹 의 표현 기준의 하나인 DAML로 변환하는 알고리즘이 향후 연구되어야 할 과제임을 논한다

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.606-607
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• 2014

Due to Web Services' platform and language independent nature, many business corporations have used them for the integration of various applications. However, the growing amount of available Web Services on Web forms a new problem - how to select and recommend an appropriate Web Service that matches the user requirements. In this paper, we investigate recommendation methods in Web Services, and discuss their strength and limitations.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.77-86
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• 2009

At present, Web services become main means to construct web applications. As the number of web services grows and various kind of web services have been produced, QoS properties of web services are one of important criteria to select more appropriate web services. However, the selected web services may become inappropriate for the Requester's requirements, because QoS is kind of dynamic properties. this paper proposes a framework that proposed that finds an appropriate web service for Requester's QoS requirements, and dynamically replaces an inappropriate web service with right one. The problems which happen in substitution step are also identified and the solutions are described with an illustrative example.

• The KIPS Transactions:PartD
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• v.14D no.3 s.113
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• pp.319-328
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• 2007

As the coverage of Web services become wider and the number of implementation cases is growing, the importance of applying the Web services quality model to real world is increased. For maintaining the level of Web services qualify, it should be required to study on assurance method of Web services qualify level. Assurance for Web services, which is newly proposed by OASIS TC, means the totality of activities for managing the quality level of them. For managing Web service quality, Web service associates could usually use SLA(Service Level Agreement) method in which a service consumer contracts for some service level with a service provider and gives for penalty or pays incentives according to the result of evaluation of services. But, there are some difficulties in applying SLA to Web services, because Web services have publicity, multiple users, and 3rd party for management. So, we need a new assurance method for Web service by considering the characteristics of Web services. This paper provides the new concept of committed assurance level for Web services. This concept can be defined as the set of maximum level of quality expected by each user, which provide the consistent view of Web service quality. This paper presents the method for duality associates to preserve some quality level of Web service by using this concept.

• Journal of Information Processing Systems
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• v.4 no.2
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• pp.53-60
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• 2008

The Web Services infrastructure is a distributed computing environment for service-sharing. Mechanisms for Web services Discovery proposed so far have assumed a centralized and peer-to-peer (P2P) registry. A discovery service with centralized architecture, such as UDDI, restricts the scalability of this environment, induces performance bottleneck and may result in single points of failure. A discovery service with P2P architecture enables a scalable and an efficient ubiquities web service discovery service that needs to be run in self-organized fashions. In this paper, we propose an autonomic -interleaving Registry Overlay Network (RgON) that enables web-services' providers/consumers to publish/discover services' advertisements, WSDL documents. The RgON, doubtless empowers consumers to discover web services associated with these advertisements within constant D logical hops over constant K physical hops with reasonable storage and bandwidth utilization as shown through simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.765-768
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• 2007

In this paper, the security evaluation method about mobile web services message is suggested in the method for improving the safety an reliability about the mobile web services message. In order that the goal of this paper is accomplished, the security threat and the security vulnerability which can be occurred in the mobile web services message are defined. The evaluation method for performing the security evaluation about the mobile web services message is defined. Also, the requirements for the mobile web services message security evaluation are defined. Finally, the evaluation framework for performing the mobile web services message security evaluation is constituted, and the evaluation scenario example is suggested. By using the mobile web services message security evaluation defined in the paper, before the mobile web services is deployed, the security threats and security vulnerability can be verified. Also, the countermeasure for the security threat and security vulnerability discovered in the verification result can be prepared. Therefore, the sorority and reliability about the mobile web services can be improved.