I am pleased to bring you Web Services Research and Practices. Web services technology has been widely admitted as the future technology for Internet computing and distributed computing. As the second volume in the IGI Advanced Book Series, this book provides researchers, practitioners, and educators with the most current research results in the field in 10 chapters. The chapter discusses the overhead of network bandwidth using SOAP for service integration. The authors explore compression strategies through a detailed survey and evaluation of state-of-the-art binary encoding techniques for SOAP. The chapter also introduces an experimental concept for SOAP compression based on differential encoding, which makes use of the commonly available WSDL description of a SOAP Web service. The chapter presents a network adaptable middleware that strikes a compromise between the encoding/decoding and associated overhead of data compression to enhance response time of Web services. Chapter III is titled " Realizability Analysis of Top-Down Web Service Composition Specifications " by Xiang Fu, Tevfik Bultan, and Jianwen Su. The chapter presents " conversation protocol, " a top-down specification approach to study the realizability problem of conversation protocols.

Dynamic Web data sources – sometimes known collectively as the Deep Web – increase the utility of the Web by providing intuitive access to data repositories anywhere that Web access is available. Deep Web services provide access to real-time information, like entertainment event listings, or present a Web interface to large databases or other data repositories. Recent studies suggest that the size and growth rate of the dynamic Web greatly exceed that of the static Web, yet dynamic content is often ignored by existing search engine indexers owing to the technical challenges that arise when attempting to search the Deep Web. To address these challenges, we present DYNABOT, a service-centric crawler for discovering and clustering Deep Web sources offering dynamic content. DYNABOT has three unique characteristics. First, DYNABOT utilizes a service class model of the Web implemented through the construction of service class descriptions (SCDs). Second, DYNABOT employs a modular, self-tuning system architecture for focused crawling of the Deep Web using service class descriptions. Third, DYNABOT incorporates methods and algorithms for efficient probing of the Deep Web and for discovering and clustering Deep Web sources and services through SCD-based service matching analysis. Our experimental results demonstrate the effectiveness of themore » service class discovery, probing, and matching algorithms and suggest techniques for efficiently managing service discovery in the face of the immense scale of the Deep Web.« less

We present a service-oriented architecture and a set of techniques for developing wrapper code generators, including the methodology of designing an effective wrapper program construction facility and a concrete implementation, called XWRAPComposer Our wrapper generation framework has two unique design goals. First, we explicitly separate tasks of building wrappers that are specific to a Web service from the tasks that are repetitive for any service, thus the code can be generated as a wrapper library component and reused automatically by the wrapper generator system. Second, we use inductive learning algorithms that derive information flow and data extraction patterns by reasoning about sample pages or sample specifications. More importantly, we design a declarative rule-based script language for multi page information extraction, encouraging a clean separation of the information extraction semantics from the information flow control and execution logic of wrapper programs. We implement these design principles with the development of the XWRAPComposer toolkit, which can semi-automatically generate WSDL-enabled wrapper programs. We illustrate the problems and challenges of multipage data extraction in the context of bioinformatics applications and evaluate the design and development of XWRAPComposer through our experiences of integrating various BLAST services.

We present a service-oriented architecture and a set of techniques for developing wrapper code generators, including the methodology of designing an effective wrapper program construction facility and a concrete implementation, called XWRAPComposer. Our wrapper generation framework has two unique design goals. First, we explicitly separate tasks of building wrappers that are specific to a Web service from the tasks that are repetitive for any service, thus the code can be generated as a wrapper library component and reused automatically by the wrapper generator system. Second, we use inductive learning algorithms that derive information flow and data extraction patterns by reasoning about sample pages or sample specifications. More importantly, we design a declarative rule-based script language for multi-page information extraction, encouraging a clean separation of the information extraction semantics from the information flow control and execution logic of wrapper programs. We implement these design principles with the development of the XWRAPComposer toolkit, which can semi-automatically generate WSDL-enabled wrapper programs. We illustrate the problems and challenges of multi-page data extraction in the context of bioinformatics applications and evaluate the design and development of XWRAPComposer through our experiences of integrating various BLAST services.

In a distributed Web service integration environment, the selection of Web services should be based on their reputation and quality-of-service (QoS). Various trust models for web services have been proposed to evaluate the reputation of Web services/service providers. Current mechanisms are based on tracing the feedbacks to the past behaviors of Web services. However, very few of them consider the robustness and attack-resiliency of the trust models. In this paper, we present an attack resilient distributed trust management system in a Web service management environment. The proposed attack resilient trust model uses two vectors to capture the behavior and the trustworthiness of a Web service/service provider based on our analysis on the possible attacks against the trust models. We also present a set of experiments that show the effectiveness of our trust model in detecting malicious behavior of service providers.

This paper presents a service-oriented framework for the development of wrapper code generators, including the methodology of designing an effective wrapper program construction facility and a concrete implementation, called XWRAPComposer. Three unique features distinguish XWRAPComposer from existing wrapper development approaches. First, XWRAPComposer is designed to enable multi-stage and multi-page data extraction. Second, XWRAPComposer is the only wrapper generation system that promotes the distinction of information extraction logic from query-answer control logic, allowing higher level of robustness against changes in the service provider's Web site design or infrastructure. Third, XWRAPComposer provides a user-friendly plug-and-play interface, allowing seamless incorporation of external services and continuous changing service interfaces and data format.