Web Service Discovery Approach Among Available WSDL/WADL Web Component

Shared-Repository based Approach for Storing and Discovering web Services

최근에 동적으로, 즉 요구가 있는 즉시 서비스들을 조합하는 동적 웹 서비스 조합은 가장 큰 관심사 중 하나이다. 지금까지 동적 웹 서비스조합에 관한 많은 연구들이 수행되어졌는데 주로 사람이 개입된 반자동 대화식 조합 기법들이 제안되었다. 또한 이들 연구에서 탐색 알고리즘 및 워크플로우 설계 기법들이 부분적으로는 기술되어 있으나. 웹 서비스 조합 자동화를 위한 전반적인 워크플로우 처리과정을 기술한 연구는 아직 없다. 본 논문은 웹 서비스 조합 자동화 기법에 초점을 맞추고 있다. 주된 아이디어는 시멘틱 웹을 실현하기 위한 웹 온톨로지와 비즈니스분야에서 성공적으로 활용되고 있는 워크플로우 기법들을 적용하여 웹 서비스 조합 자동화 시스템을 구현하는 것이다. 본 연구에서는 웹 서비스발견을 위해 매칭 알고리즘이 제안되고, 웹 서비스들 간 상호연결을 지원하기 위해 매칭 알고리즘에 온톨로지 개념이 적용된다. 그리고 웹 서비스 조합 자동화를 지원하기 위한 워크플로우 실행계획이 기술된다. 마지막으로 실 데이터 실험을 통해 제안 시스템의 우수성을 보인다. 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.

Web service (WS) discovery is a prerequisite for achieving WS composition and orchestration. Although a lot of research has been conducted on the functional discovery of WSs, the proposed techniques fall short when faced with the foreseen increase in the number of (potentially functionally-equivalent) WSs. The above situation can be resolved with the addition of non-functional (quality of service (QoS)) discovery mechanisms to WS discovery engines. QoS-based WS matchmaking algorithms have been devised for this reason. However, they are either slow - as they are based on ontology reasoners - or produce inaccurate results. Inaccuracy is caused both by the syntactic matching of QoS concepts and by wrong matchmaking metrics. In this paper, we present two constraint programming (CP) QoS-based WS discovery algorithms for unary constrained WS specifications that produce accurate results with good performance. We also evaluate these algorithms on matchmaking time, precision and recall in different settings in order to demonstrate their efficiency and accuracy.

Efficient Discovery and Ranking of Web Services Using Non-functional QoS Requirements for Smart Grid Applications

With the rapid growth and adoption of web-based technologies, more and more service providers offer various services on the web. This can facilitate the organizations to develop business applications using web services composition over the Internet according to their business requirements. The primary requirement for developing composite web service is to discover the most relevant web service for realizing each function of the required composite web service. Finding the most relevant web service is still a challenging task. In this paper, we propose web service discovery approach that incorporates web services clustering. Clustering technique combines latent Dirichlet allocation(LDA) and k-Medoids and reduces search space for web service discovery. Web service discovery uses a match-making algorithm that utilizes WordNet database and Hungarian method to compute the semantic similarity score for a web service based on the requested query. Experimental results show that the proposed approach performs better than LDA-based approach.

In modern heterogeneous environments, such as mobile, pervasive and ad-hoc networks, architectures based on web services offer an attractive solution for effective communication and inter-operation. In such dynamic and rapidly evolving environments, efficient web service discovery is an important task. Usually this task is based on the input/output parameters or other functional attributes, however this does not guarantee the validity or successful utilization of retrieved web services. Instead, non-functional attributes, such as device power features, computational resources and connectivity status, that characterize the context of both service providers and consumers play an important role to the quality and usability of discovery results. In this paper we introduce context-awareness in web service discovery, enabling the provision of the most appropriate services at the right location and time. We focus on context-based caching and routing for improving web service discovery in a mobile peer-to-peer environment. We conducted a thorough experimental study, using our prototype implementation based on the JXTA framework, while simulations are employed for testing the scalability of the approach. We illustrate the advantages that this approach offers, both by evaluating the context-based cache performance and by comparing the efficiency of location-based routing to broadcast-based approaches.

Web services (WS) is called composite or compound when its execution involves interactions with other WS to utilize their features. The service providers published the web services through the internet as independent software components that are fulfilling the requirements of customer request. Clustering is more necessary for efficient web service discovery and web service composition processes. Clustering process groups the similar type of web services. In this paper, efficient clustering methods such as k-means clustering, Hierarchical agglomerative clustering and Balanced Iterative Reducing and Clustering using Hierarchies (BIRCH) clustering are introduced for web service clustering. The k-means clustering is a kind of partitional clustering where the web pages are divided into subsets with no hierarchy defined over them and the hierarchical agglomerative clustering is a type of hierarchical clustering where the web pages are arranged in tree structure in which leaves represents the data points and nodes denotes the clusters. BIRCH is an integrated hierarchical clustering algorithm uses the clustering features and cluster feature tree for general cluster description. Based on these clustering methods, web pages are clustered which are used for web service discovery and web service composition. The experiments are conducted on number of web services and the efficiency is evaluated in terms of accuracy, precision, recall and run time.

This paper demonstrates an experimental study that examines the accuracy of various information retrieval techniques for Web service discovery. The main goal of this research is to evaluate algorithms for semantic web service discovery. The evaluation is comprehensively benchmarked using more than 1,700 real-world WSDL documents from INEX 2010 Web Service Discovery Track dataset. For automatic search, we successfully use Latent Semantic Analysis and BM25 to perform Web service discovery. Moreover, we provide linking analysis which automatically links possible atomic Web services to meet the complex requirements of users. Our fusion engine recommends a final result to users. Our experiments show that linking analysis can improve the overall performance of Web service discovery. We also find that keyword-based search can quickly return results but it has limitation of understanding users' goals.

The expansion of web service provider's number over the web has motivated the research community to invest in web service discovery area. However, in order to efficiently identify appropriate services, web services requesters should express their requests in rich, standard and machine-readable manner. In this context, we propose the use of a Service Request Template based on SAWSDL and WS-Policy standards. We use SAWSDL language which constitutes an extension of WSDL to express both functional and semantic needs, while we use WS-Policy framework to specify both non-functional requirements and user's preferences. We think that the proposed template would make it possible to overcome problems due to the heterogeneity between web services requests and published web services when executing discovery process. To perform efficient service discovery, we develop a structure-based matching algorithm that offers three mechanisms: semantic, data types and policy matching.

One of the major challenges of the Service Oriented Computing (SoC) paradigm is the Web service discovery. Yet the mechanisms used to match Web services can be improved. However, considering the semantics of the Web service descriptions is a must for automating the process of discovering Web services. We have proposed a semantic-based Web service discovery algorithm that consists of two stages: The registry filtering stage and the descriptions matching stage. The aim of the first stage is to pick the advertisements that are relevant to the client request and ignore, from an early stage and before checking the details of the descriptions, the advertisements that are not able to satisfy the client request. However, the aim of the second stage is to check whether or not the relevant advertisements resulted from the registry filtering stage are actually able to satisfy the client query. This paper concerns the first stage. More precisely, we propose a semantic-based Web service registry filtering mechanism that takes the responsibility of narrowing down the number of Web service descriptions to be checked in detail to the number of only the relevant advertisements to the client request. We also propose an extension to Web Ontology Language for Services (OWL-S). With this extension, filtering the Web service registry based on the semantics of the available descriptions is possible.KeywordsClient RequestGlobal CategoryClient QueryRelevant AdvertisementThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Due to the emergence of Internet technologies and service-oriented computing, there is a rapid growth in the quantity and variety of services on the web. Discovering the web services as per the request is not an easy task because of the advancement of service-oriented computing which includes web services, cloud services, mobile services, etc. These services are dynamic and published according to the emerging standards in repositories. Web service clustering plays a crucial role in web service discovery. When services are grouped according to the similarity, then it reduces the search space and time, so that services can be discovered efficiently. Many eminent researchers have proposed approaches for efficient web service discovery by incorporating web service clustering. In this paper, we review different approaches that are proposed for web service clustering to enhance the discovery process. A comparison among existing approaches is carried out based on the vector representation approach, dimensionality reduction technique, method to capture semantic relationship among features, clustering technique, type of input dataset, number of web services in dataset and service repository. This review will help the researchers to understand the existing techniques to group services in similar clusters to improvise service discovery and the scope for improvement by future directions.KeywordsService-oriented architectureWeb services/Web APIWeb service clusteringWeb service discovery

Nowadays, with the advancement in mobile technologies, the use of web services has seen an explosion in interest for mobile computing environment. However, the heavyweight nature of conventional web services to be deployed on mobile devices brings new challenges in mobile computing in the coming future. Web services technology and mobile computing domains are converging at their intersection which leads to Mobile Web Services (MWS) which enables the service access in users’ mobile device. As the numbers of web services are increasing dramatically, the web service discovery becomes more important to discover the usable web services in effective and efficient manner. This paper discusses an overview of mobile challenges in MWS recent research, and a summary of the issues. Moreover, current approaches of Mobile Web Services Discovery are classified and these approaches are compared to some criteria. The results of this study will help researchers to deliver more applicable solutions with the most appropriate approaches for Mobile Web Services Discovery.KeywordsWeb ServicesMobile Web Serviceweb service discoverymobile computingmobile web service discovery

Semantic Web Services are the key technology providing services for the users' convenience in the semantic web environment. Many companies in various fields are researching and developing languages for constructing Semantic Web Services such as DAML-S, WSDL, X-LANG and BPEL4WS. DAML-S is a method that accesses the existing Web Service method from a semantic web environment. However, the current Semantic Web Services Discovery System does not provide sufficient processing of quality factors (performance, accessibility, availability, reliability and transaction) nor reliable and accurate service results desired by the user through a UDDi search method. The present study analyzes the disadvantages of the current web services and suggests a Semantic Web Services Discovery System based on QoS applying semantic web technologies as a solution to the problems. The suggested system provides a UDDi and DAML-S based discovery engine to allow efficient web service discovery and composition.

Directory services are a genuine constituent of any distributed architecture which facilitate binding attributes to names and then querying this information, that is, announcing and discovering resources. In such contexts, especially in a business environment, Quality of Service (QoS) and non-functional properties are usually the most important criteria to decide whether a specific resource will be used. To address this problem, we present an approach to the semantic description and discovery of web services which specifically takes into account their QoS properties. Our solution uses a robust trust and reputation model to provide an accurate picture of the actual QoS to user. The search engine is based on an algebraic discovery model and uses adaptive query-processing techniques to parallelise expensive operators. Architecturally, the engine can be run as a centralised service for small-scale environments or can be distributed among any number of cooperating registry providers.

Web services are the new paradigm for distributed computing. They offer interoperability of application and integration of large scale distributed systems. Amongst the web service standards, service registry is crucial to the overall utility of web service technology. However, the web services discovery mechanism pertaining with the UDDI [1] registry is inefficient because it only supports keyword-based and category-based matching, leading to irrelevant matches. Therefore, the provision of the scalable, flexible and robust web services publication and discovery system is crucial for the overall utility of web services. In this paper, we develop a scalable, robust and efficient infrastructure for web services publication and discovery amongst domain-based registries. More importantly, a novel algorithm is provided to classify web services into domain-based registries based on their semantic description. Experimental results show that our approach outperforms a centralized approach in terms of service discovery time.