Meta web service: building web-based open decision support system based on web services

Web services are currently one of the trends in network-based business services, which intuitively will be applied to build a semantic web-based decision support system (DSS). Since web services are self-contained, modular business process applications, based on open standards, enable integration models for facilitating program-to-program interactions. Decision modules in a semantic web-based DSS can be viewed as a web service. However, according to the current features, web services know only about themselves, they are neither autonomous, nor are they designed to use ontologies; they are passive until invoked, and they do not 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 DSS. The meta web service understands the user's problem statement with ontology, performs web service discovery, web service composition, and automatically generates codes for composite web service execution. Case-based reasoning is applied to quickly find past histories of successful service compositions. A prototype of research web service has been developed to show the feasibility of the proposed idea.     

An intelligent web service group-based recommendation system for long-term composition

A modern model long-term composed service (LCS) with a group recommendation system has an indefinite lifespan. An LCS is used as a long-term business goal, and for a business committed to its customers, support will be provided to customers enabling them to book, e.g. an automotive service through online web services by providing information that the LCS then uses to offer more support. However, identifying the exact service to meet the user requirement is essential. Service composition has been identified as the key task in achieving various QoS performances. There exist various approaches that involve service composition according to the throughput and popularity. However, they fail to achieve the expected performance. Towards improving the performance of the LCS, a novel LCS that is based on the user queries of a group of persons is developed to give the best business services based on previous travel details and services. The method carries out service selection and composition according to the ratings provided by users towards any service. Additionally, the method considers the user-to-service rating and service-to-service rating, which are measured according to the coupling quality. Therefore, the proposed novel LCS provides better services based on the user ratings for particular business queries. The method ranks the services according to the rating values to perform service composition, with consideration of the detection of similar user groups and utilization of the rating values in service selection. We aim to propose a novel LCS work based on group ratings and a group of services. This work is intended to reduce the time complexity of changes in the LCS network using the group recommendation system.

     

基于FAHP与规划图融合的Web服务组合方法

近年来,随着云计算的发展,越来越多的服务被发布在网上。如何将不同的Web服务组合在一起并使其满足功能性需求和非功能性需求成为了一个研究难点。Web服务质量(Quality of Service,QoS)感知的Web服务组合问题属于NP难问题。为了解决这个问题,文中提出一种融合FAHP与改进Graphp lan算法的方法(FAHP and Improved Graphplan,FIGP)。首先,根据用户偏好使用模糊分析层生成服务的综合QoS;其次,在Graphplan向前扩展中,使用动态阈值对竞争力较差的服务进行剪枝,在保留关键服务的同时降低了时间复杂度;最后,在Graphplan向后搜索阶段,在满足功能性需求的前提下选择综合QoS最好的服务加入到组合中。实例分析和实验结果表明,与普通的Graphplan,Skyline及其他方法相比,FIGP不仅较好地提高了服务组合的质量,而且显著缩短了程序的执行时间。     

Synthy: A system for end to end composition of web services

The demand for quickly delivering new applications is increasingly becoming a business imperative today. However, application development is often done in an ad hoc manner resulting in poor reuse of software assets and longer time-to-delivery. Web services have received much interest due to their potential in facilitating seamless business-to-business or enterprise application integration. A web service composition system can help automate the process, from specifying business process functionalities, to developing executable workflows that capture non-functional (e.g. Quality of Service (QoS)) requirements, to deploying them on a runtime infrastructure. Intuitively, web services can be viewed as software components and the process of web service composition similar to software synthesis. In addition, service composition needs to address the build-time and runtime issues of the integrated application, thereby making it a more challenging and practical problem than software synthesis. However, current solutions based on business web services (using WSDL, BPEL, SOAP, etc.) or semantic web services (using ontologies, goal-directed reasoning, etc.) are both piecemeal and insufficient. We formulate the web service composition problem and describe the first integrated system for composing web services end to end, i.e., from specification to deployment. The proposed solution is based on a novel two-staged composition approach that addresses the information modeling aspects of web services, provides support for contextual information while composing services, employs efficient decoupling of functional and non-functional requirements, and leads to improved scalability and failure handling. We also present Synthy, a prototype of the service composition system, and demonstrate its effectiveness with the help of an application scenario from the telecom domain.     

Context-Aware Web Service Composition based on AI Planning

A web service is an application that is published on the web and can be discovered and used automatically. In many cases, a web service cannot provide the capability that the user has requested. Therefore, according to the user request, it should be possible to combine various services and produce a new composite service for the user request. Context is the information that can be used to characterize the situation of an entity. In this paper, we present our context model for web service composition and implement the newly proposed framework for context-aware web service composition and show how the newly proposed framework reduces the number of failures and composition time.     

基于QoS的自适应控制中间件研究与应用

文章重点研究在自适应控制中间件支持下,Web服务组合执行引擎的QoS管理机制,设计了一个基于QoS的自适应控制中间件,并应用于Web服务组合执行引擎当中,以支持对服务请求的分级处理,实现了为不同等级用户提供区分服务的功能,为提高可变负载下单个执行引擎的高吞吐量和快速响应时间提供了一种有效的解决方案。     

A cloud computing platform for ERP applications

Cloud computing enables many applications of Web services and rekindles the interest of providing ERP services via the Internet. It has the potentials to reshape the way IT services are consumed. Recent research indicates that ERP delivered thru SaaS will outperform the traditional IT offers. However, distributing a service compared to distributing a product is more complicated because of the immateriality, the integration and the one-shot-principle referring to services. This paper defines a CloudERP platform on which enterprise customers can select web services and customize a unique ERP system to meet their specific needs. The CloudERP aims to provide enterprise users with the flexibility of renting an entire ERP service through multiple vendors. This paper also addresses the challenge of composing web services and proposes a web-based solution for automating the ERP service customization process. The proposed service composition method builds on the genetic algorithm concept and incorporates with knowledge of web services extracted from the web service platform with the rough set theory. A system prototype was built on the Google App Engine platform to verify the proposed composition process. Based on experimental results from running the prototype, the composition method works effectively and has great potential for supporting a fully functional CloudERP platform.     

OntoPipeliner: An ontology-based automatic semantic service pipeline generator

The Web is a distributed environment rich with Web services going through continual metamorphosis; thus, sustaining semantic stability of service composition has become a major challenge. Automatic service composition – enabled both by the use of ontologies that describe service domains and by user-specified constraints bound to the ontologies – provides us candidate service pipelines at composition design time. The ontology-based languages for semantically describing web services, such as OWL-S, have been widely used. Though rich and comprehensive in their expressiveness, the use of these languages still leaves much of composition process manual. In this work, we present an ontology-based semantic web service composition system called OntoPipeliner. It employs a novel way of utilizing characteristics of Web services that reflect the classes and properties of domain ontologies and provides the ontology-guided constraints for automatic composition of services, in order to guide the user toward the best pipeline that meets the user requirements.     

The realization of service-oriented e-Marketplaces

Electronic Marketplaces (or e-Marketplaces) require technologies which provide support for the adaptability, flexibility and the integration of business applications in order to meet rapid changes in business environment. Traditional web technologies are unable to meet the new business requirements which are derived from the rapid growth of e-Marketplaces. In this research, a service-oriented framework is proposed in order to address the issues associated with the development of e-Marketplaces. Specifically, it introduces a generic trading model oriented to e-Marketplaces so as to overcome the inadequacy of existing models and to facilitate the development of a computational trading process. In the proposed framework, required services are identified through the utilization of the business-centric trading model. Using a service metamodel, services are equipped with intelligence such that they work seamlessly and coherently within and across e-Marketplaces. A multi-model driven integrated development platform has been developed to support the proposed models and framework. The proposed framework and concepts have been validated through a case study of a mutual funds auction in an e-Marketplace.

基于Web服务的动态工作流系统的研究与实现

分析了面向服务的计算环境及服务组合的新特征和新问题，并在此基础上从面向业务用户的角度对基于Web服务的动态工作流进行了探讨，提出一种基于Web服务的动态工作流模型。以该模型为基础，设计了具有三层结构的基于Web服务的动态工作流系统，按照该架构并基于J2EE平台实现了系统．对基于web服务的动态工作流应用提供了系统支撑与验证环境。     

PBA4WSSP: a policy-based architecture for web services security processing

Due to the dynamic, heterogeneous and interorganizational nature, different web services and different ports or operations in the same service, even the same services at different times may have their different security requirements because of their different security domains and different business backgrounds. How to design a flexible, fine-grained and comprehensive architecture for web services security processing has become a matter of great urgency. However, no ideal solutions have been worked out for these problems. As a result of our study, we have presented in this paper a policy-based architecture termed policy-based architecture for web services security processing (PBA4WSSP) to meet the dynamic, complete and fine-grained security requirements. In PBA4WSSP, the processing of all security problems is based on security policy in service stage to support flexibly security configuration. Moreover, we have designed a service policy model to describe the fine-grained security requirements. And the conversion method between security policy model and security policy expression has also been described. In addition, a staged complete security processing architecture is provided to reduce the dependency among protocol implementations. Furthermore, with PBA4WSSP, a web service security module has been designed and implemented as well. Eventually, the performance evaluation results amply demonstrate that our system is flexible and usable.     

Web服务动态组合方法研究与设计

目前基于工作流的Web服务组合方法大多要求预先定义流程结构,不能适应现代企业业务流程复杂多变的需求.提出了一种Web服务动态组合方法,将流程中动态部分用黑盒子流程进行封装,在执行时根据预定义规则和用户需求将黑盒子流程自动组合展开为实际运行流程.对具体服务、抽象服务、黑盒子流程等概念和服务选取规则、服务组合规则进行了定义,详细描述黑盒子流程展开算法,并设计了一个实现动态服务流程组合的框架结构.     

基于Web服务的动态工作流系统的研究与实现

分析了面向服务的计算环境及服务组合的新特征和新问题,并在此基础上从面向业务用户的角度对基于Web服务的动态工作流进行了探讨,提出一种基于Web服务的动态工作流模型。以该模型为基础,设计了具有三层结构的基于Web服务的动态工作流系统,按照该架构并基于J2EE平台实现了系统,对基于Web服务的动态工作流应用提供了系统支撑与验证环境。     

Efficient support for interactive service in multi-resolution VOD systems

Advances in high-speed networks and multimedia technologies have made it feasible to provide video-on-demand (VOD) services to users. However, it is still a challenging task to design a cost-effective VOD system that can support a large number of clients (who may have different quality of service (QoS) requirements) and, at the same time, provide different types of VCR functionalities. Although it has been recognized that VCR operations are important functionalities in providing VOD service, techniques proposed in the past for providing VCR operations may require additional system resources, such as extra disk I/O, additional buffer space, as well as network bandwidth. In this paper, we consider the design of a VOD storage server that has the following features: (1) provision of different levels of display resolutions to users who have different QoS requirements, (2) provision of different types of VCR functionalities, such as fast forward and rewind, without imposing additional demand on the system buffer space, I/O bandwidth, and network bandwidth, and (3) guarantees of the load-balancing property across all disks during normal and VCR display periods. The above-mentioned features are especially important because they simplify the design of the buffer space, I/O, and network resource allocation policies of the VOD storage system. The load-balancing property also ensures that no single disk will be the bottleneck of the system. In this paper, we propose data block placement, admission control, and I/O-scheduling algorithms, as well as determine the corresponding buffer space requirements of the proposed VOD storage system. We show that the proposed VOD system can provide VCR and multi-resolution services to the viewing clients and at the same time maintain the load-balancing property. Received June 9, 1998 / Accepted April 26, 1999     

基于颜色Petri网的服务组合建模与验证

Web服务组合技术能快速、灵活的满足复杂多变的业务需求,Web服务组合及其形式化描述和验证已经成为Web服务中一个非常重要的研究方向.给出了一个基于颜色Petri网(CPN)的Web服务和Web服务组合的形式化定义和描述,主要描述了4种组合结构:顺序、选择、并发和循环.给出了一个颜色Petri网建模Web服务组合的实例,并且对模型进行了简单的正确性分析.分析结果表明,该建模方法满足正确性要求.     

关于Web服务组合的有效Web服务发现机制

随着Web Services的广泛流行,怎样发现适当Web Services来支持Web Services的组合已经成为一种挑战.由于传统的关键字搜索具有太低的记忆性和精确性,因此这种方法是很低效的.基于Web Services的描述信息,介绍了一种有效的Web Services发现机制.此服务发现方法是简单可用的,通过引入语义变得十分高效,因此该机制成功的在服务组合模型上得到了实现.     

An experience report on developing an automated web services platform

Web services have attracted significant industry interest as a low-cost and flexible technology alternative to distributed object and proprietary message-oriented methods for delivery of on-demand business processes, enabling intra-organizational systems integration, and in the long term, development of dynamic inter-organizational process networks that may revolutionize B2C and B2B e-commerce. Exploiting this latent potential of web services technology requires the development of automated techniques for scalable and reliable service composition and execution in web service platforms. In this paper, we summarize our experience in developing an architectural framework for web services platforms, called Integrated Service Planning and Execution architecture (ISP & E). The use of recent advances in AI planning, learning and semantic web technologies for service composition, reliable service execution, transaction synthesis, and model-driven deployment of services is discussed. Furthermore, we discuss implications for and research issues in the development of web services based systems to aid e-business.     

Constructing scalable Internet of Things services based on their event‐driven models

Even though many IoT (Internet of Things) applications have been implemented based on distributed events, how to construct scalable IoT services is still unclear. In this paper, we first discuss representing physical entities as IoT resources in the cyber world and integrate them into IoT services and then use an event session mechanism to express the coordination logic in an IoT service system. Given their event‐driven models, the scalable IoT services are constructed through decoupling one service at behavior from others, where running atomic service instances with high concurrency is our first focus, and distributed execution of an IoT business process is our second focus. Our last focus is to make each distributed business process execution unit hold its properties in the whole process, which requires modeling the environment as a prerequisite to compute its properties, and some assume‐guarantee rules for composing the services from the environment's perspective. We then propose a platform to support the construction, where according to the behavior decoupling features, one IoT business process is decomposed into pieces of event composition logic and business computation logic, together with separating the data dependency of computation functions in each process fragment, such that it can be concurrently executed and distributed. A practical application is implemented to concept‐prove our work. Copyright © 2015 John Wiley & Sons, Ltd.     

XrML-RBLicensing approach adapted to the BPEL process of composite web services

Web service orchestration represents an open and standards-based approach for connecting web services together leading to higher level of business processes. Business Process Execution Language (BPEL) engines are designed to handle this orchestration. However, web service compositions into BPEL suffer from several non-functional requirements such as security. To address this problem, we propose in this paper a novel approach that is based on a harmony between the licensing concept offered by eXtensible rights Markup Language (XrML), aspect-oriented programming (AOP), and web service compositions in BPEL. Our proposed approach, based on XrML, offers the ability to associate security licenses with activities offered by the composite web services. It allows to automatically generate BPEL aspects depending on the developed licenses, to separate between crosscutting concerns of the composed web services, and provides an easy way to include and update the non-functional requirements (e.g., security) into a BPEL process. It offers also the ability to validate the licenses, at runtime and without affecting the business logic of this model. To evaluate our approach, we have developed an inventory control system (ICS) sample that is composed of several web services. Case study and performance analysis are presented to demonstrate its feasibility as well.