• The KIPS Transactions:PartD
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• v.12D no.6 s.102
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• pp.889-898
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• 2005

Recently, one of the most challenging problems is to compose web services dynamically, that is, on demand. A number of researchers have been considerably interested in the dynamic web services composition. However, while most of them focused on the semi-automatic web services composition with a human controller, very little attention was devoted to the full automation of this process. This paper primarily focuses on the automatic web services composition techniques. The main idea is to implement an automatic web services composition system using web ontologies to realize the semantic web and workflow technologies to play a major role in E-businesses. In this paper, we propose a matching algorithm for web service discovery and present an approach based on the use of ontologies to facilitate the interoperability of web services. Finally, we describe a workflow execution plan to support the automatic web services composition, and an experimental study that shows the high performance of our system.

• The KIPS Transactions:PartD
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• v.15D no.1
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• pp.113-120
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• 2008

Web Services composition has gained a considerable attention because of the widespread use of the Web Services and SOA. Recently, various researches on automatic Web Services composition are on going to realize more dynamic and intelligent SOA environments. However, there is no complete solution for automatic Web Services composition now and previous researches have several problems. Automatic composition based on syntactic information has low correctness through incorrect semantic linking. Moreover, many researches make an process as the result of composition which is hard for actual execution. In this paper, improved automatic Web Services composition based on Web Services choreography is proposed. In this system, the correctness is improved and the result of composition is more concrete process.

• 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.

• Journal of KIISE:Software and Applications
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• v.36 no.3
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• pp.187-199
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• 2009

With the advent of Web 2.0, OpenAPIs are becoming an increasing trend to emphasize Web as platform recently. OpenAPIs are used to combine services and generate new services by mashup. However because the standard documents for OpenAPIs do not exist, it may restrict the use of OpenAPIs. Previous studies of OpenAPIs mashup have been limited to tool design or language definition for service combination rather than dynamic composition. On the other hand, Web services that are a software technology implementing SOA provide standard documents such as WSDL to explain each service, UDDI to register it, and SOAP to transfer messages. Thus Web applications can interpret and execute services by using these technologies. Recent works have also been performed to provide semantic features and dynamic composition for SOA. If a dynamic and systematic approach is provided to combine Web services and OpenAPIs, Web applications can provide users with diverse services. In this study, we present a SOA based framework for mashup of OpenAPIs and Web services. The framework supports dynamic composition of OpenAPIs and Web services, where the process of composite services is described in OWL-S. A prototype is provided to validate our framework. The framework is expected to add diversity to typical Web services.

• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.91-97
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• 2017

IoT (Internet of Things) systems are based on heterogeneous hardware systems of different types of devices interconnected each other, ranging from miniaturized and low-power wireless sensor node to cloud servers. These IoT systems composed of heterogeneous hardware utilize data sets collected from a particular set of sensors or control designated actuators when needed using open APIs created through abstraction of devices' resources associated to service applications. However, previously existing IoT services have been usually developed based on vertical platforms, whose sharing and exchange of data is limited within each industry domain, for example, healthcare. Such problem is called 'data silo', and considered one of crucial issues to be solved for the success of establishing IoT ecosystems. Also, IoT services may need to dynamically organize their services according to the change of status of connected devices due to their mobility and dynamic network connectivity. We propose a way of dynamically composing IoT services under the concept of WoT (Web of Things) where heterogeneous devices across different industries are fully integrated into the Web. Our approach allows developers to create IoT services or mash them up in an efficient way using Web objects registered into multiple standardized horizontal IoT platforms where their resources are discoverable and accessible. A Web-based service composition tool is developed to evaluate the practical feasibility of our approach under real-world service development.

• Asia pacific journal of information systems
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• v.13 no.2
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• pp.145-170
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• 2003

Open Decision Support System(DSS) is an automated and transparent system that is built to be shared both within and across organizations. The open DSS has been thought to be a set of decision components that are communicating through Web protocols. These characteristics intuitively invite the Web services concepts, which are currently one of the new trends in network-based business services. However, web services still are not active enough to be autonomous, and to provide for composing functionalities. These lead to the motivation on building a sophisticated web service to contain these features and to utilize web services on behalf of the user. This paper aims to propose a new concept of Meta Web Service, a web service-based open DSS. Decision modules in a dynamic and open DSS can be viewed as a web service. The Meta Web Service understands the users problem statement with ontology, performs web service discovery, web service composition, and automatically generates codes for composite web service execution. A prototype of example web service has been developed to show the feasibility of the proposed idea.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1260-1281
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• 2015

As the number of services available on the Web increases, it is vital to be able to identify which services can be trusted. Since there can be an extremely large number of potential services that offer similar functionality, it is challenging to select the right ones. Service requestors have to decide which services closelysatisfy their needs, and theymust worry about the reliability of the service provider. Although an individual service can be trusted, a composed service is not guaranteed to be trustworthy. In this paper, we present a trust model that supports service discovery and composition based on trustworthiness. We define a method to evaluate trust in order to discover trustworthy services. We also provide a method to perform trust estimation for dynamic service composition, and we present results of two experiments. The proposed model allows for service requestors to obtain the most trustworthy services possible. Our mechanism uses direct and indirect user experience to discover the trustworthiness of the services and service providers. Moreover, composing services based on quantitative trust measurements will allow for consumers to acquire a highly reliable service that meet their quality and functional requirements.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.569-580
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• 2008

Web services are the current most promising technology for service oriented architecture(SOA) implementations. However, in spite of the large scale acceptance of web services, they have been relegated to internal integration projects, and the grand vision of virtual enterprises where partners can be integrated on demand is yet to be realized. The main reason is that the current standards of web services are not very suitable for the dynamic web service discovery and integration. In this paper, we present a novel SemanticBPEL solution that merges the benefit of WS-BPEL, with the advantage of OWL-S for building a semi-automatic web service composition system. In particular, this work proposes a multi-phase search method for solving dynamic discovery and integration problems of web services. The proposed method is compared with the existing keyword based retrieval method. These comparisons show that our approach outperforms the existing method.

• 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 Computing Science and Engineering
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• v.6 no.2
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• pp.89-104
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• 2012

In dynamic Web service environments, the performance of the Internet is unpredictable; the reliability and effectiveness of remote Web services are also unclear. Therefore, it can hardly be guaranteed that the quality of Web service (QoWS) attributes of Web services do not fluctuate with the dynamic Web service environments. When a composite service is planned in the context of dynamic service environments, there is another aspect which has not been taken into account by existing works, namely, concurrency - the fact that multiple requests to a composite service may arrive at the same time. Considering the dynamics of Web service environments and concurrency of requests, we propose in this paper a service selection scheme which adopts top-k dominating queries to generate a composition solution rather than only select the best composition solution for a given request. The experimental results have investigated the efficiency and effectiveness of our approach and shown that it outperforms baseline and traditional methods for service selection.