Cohesive design of personalized Web applications

Good software engineering practices, such as separating concerns and identifying patterns, simplify the critical design decisions in building personalized Web applications. The authors use the object-oriented hypermedia design method (OOHDM) for constructing customized Web applications. Incorporating well-known object-oriented design structures and techniques, OOHDM produces flexible Web application models. Designers can add personalized behavior to these models with minimal code manipulation, and reasoning over design objects yields better insight into the personalization process. Although this article casts the discussion in terms of the OOHDM primitives, the ideas presented can be easily applied to other design approaches, such as WebML     

Object-Oriented Design Structures in Web Application Models

In this paper, we discuss different object-oriented design structures that should be used in the process of building Web applications. We base our discussion on the OOHDM approach for defining a Web application model, in particular, the separation of the navigational model from the conceptual model. We focus on the systematic application of different design patterns (such as Observer and Decorator) for decoupling different aspects of a Web model. We briefly discuss some specific patterns that may appear in this kind of applications and we introduce additional concepts such as Web frameworks as a conceptual approach to maximize design reuse in Web applications.     

Web Services框架中的面向业务管理方法

面向业务环境中的基础业务，以JMX作为基础结构，提出了相应的管理准则和管理模式，生成与原有业务相关联的管理业务。以流模型为基础，以业务级约定SLA为驱动，该业务管理结构可以实现基础业务的协作，构建复杂的合成业务，实现特定的商业应用，给出了过程拓扑结构，说明了相关商业过程管理问题。最后，给出了用于监视和控制业务的度量模型的模块化构建方法。     

Developing BP-driven web applications through the use of MDE techniques

Model driven engineering (MDE) is a suitable approach for performing the construction of software systems (in particular in the Web application domain). There are different types of Web applications depending on their purpose (i.e., document-centric, interactive, transactional, workflow/business process-based, collaborative, etc). This work focusses on business process-based Web applications in order to be able to understand business processes in a broad sense, from the lightweight business processes already addressed by existing proposals to long-running asynchronous processes. This work presents a MDE method for the construction of systems of this type. The method has been designed in two steps following the MDE principles. In the first step, the system is represented by means of models in a technology-independent manner. These models capture the different aspects of Web-based systems (these aspects refer to behaviour, structure, navigation, and presentation issues). In the second step, the model transformations (both model- to-model and model-to-text) are applied in order to obtain the final system in terms of a specific technology. In addition, a set of Eclipse-based tools has been developed to provide automation in the application of the proposed method in order to validate the proposal.     

Discovering and Using Design Patterns in the WWW

In this paper, we discuss how the idea of design patterns can be used in the context of the World Wide Web, for both designing and implementing web sites or more complex information systems. We first motivate our work by discussing which are the most outstanding problems in designing Web-based information systems. Then we briefly introduce design patterns and show how they are used to record and reuse design information. We next present some simple though powerful design patterns and show known uses in the WWW. Finally, we outline a process for building applications by combining a design methodology (OOHDM) with design patterns.     

Learning by foraging: The impact of individual knowledge and social tags on web navigation processes

The World Wide Web provides a tremendously large quantity of information. When users search for information or products on the Web, they will presumably be inclined to choose their path of navigation on the basis of their prior knowledge. In those cases in which the prior knowledge of users is incorrect, however, this navigation process is assumed to lead to suboptimal search results. In an experimental study with 180 participants, we examined to what extent both the users’ prior knowledge and social tags - which capture the collective knowledge of a Web community in tag clouds - influenced the navigation of users and triggered incidental learning processes during the Web search. The results supported the assumption that the users’ prior knowledge is indeed crucial for navigation, as users followed those tags which corresponded to their internal associations. Moreover, we found that social tags also affected the navigation behavior of users, as a strong collective association of social tags led to a high selection rate for these tags. Finally, the results showed that social tags triggered incidental learning processes, as those internal associations which corresponded to tags with a strong collective association were strengthened during navigation. The implications of these findings for further research are discussed.     

Autonomic resource provisioning for software business processes

Software development nowadays involves several levels of abstraction: starting from the programming of single objects, to their combination into components, to their publication as services and the overall architecture linking elements at each level. As a result, software engineering is dealing with a wider range of artifacts and concepts (i.e., in the context of this paper: services and business processes) than ever before. In this paper we explore the importance of having an adequate engine for executing business processes written as compositions of Web services. The paper shows that, independently of the composition language used, the overall scalability of the system is determined by how the run-time engine treats the process execution. This is particularly relevant at the service level because publishing a process through a Web service interface makes it accessible to an unpredictable and potentially very large number of clients. As a consequence, the process developer is confronted with the difficult question of resource provisioning. Determining the optimal configuration of the distributed engine that runs the process becomes sensitive both to the actual number of clients and to the kinds of processes to be executed. The main contribution of the paper is to show how resource provisioning for software business processes can be solved using autonomic computing techniques. The engine separates execution in two stages (navigation and dispatching) and uses a controller to allocate the node of a cluster of computers to each one of those stages as the workload changes. The controller can be configured with different policies that define how to reconfigure the system. To prove the feasibility of the concept, we have implemented the autonomic controller and evaluated its performance with an extensive set of experiments.     

Surfing the Web backwards

``Life can only be understood backwards, but it must be lived forwards.'' Soren Kierkegaard

From a user's perspective, hypertext links on the Web form a directed graph between distinct information sources. We investigate the effects of discovering `backlinks' from Web resources, namely links pointing to the resource. We describe tools for backlink navigation on both the client and server side, using an applet for the client and a module for the Apache Web server. We also discuss possible extensions to the HTTP protocol to facilitate the collection and navigation of backlink information in the World Wide Web.     

Services Mashups: The New Generation of Web Applications

Web services are becoming a major technology for deploying automated interactions between distributed and heterogeneous applications, and for connecting business processes. Service mashups indicate a way to create new Web applications by combining existing Web resources utilizing data and Web APIs. They facilitate the design and development of novel and modern Web applications based on easy-to-accomplish end-user service compositions.     

Formalizing WSBPEL Business Processes Using Process Algebra

Industry standards for Web Service composition, such as WSBPEL, provide the notation and additional control mechanisms for the execution of business processes in Web Service collaborations. However, these standards do not provide support for checking interesting properties related to Web Service and process behaviour. In an attempt to fill this gap, we describe a formalization of WSBPEL business processes, that adds protocol information to the specifications of interacting Web Services, and uses a process algebra to model their dynamic behaviour — thus enabling their formal analysis and the inference of relevant properties of the systems being built.     

WSDL and BPEL extensions for Event Driven Architecture

ContextService Oriented Architecture (SOA) and Event Driven Architecture (EDA) are two acknowledged architectures for the development of business applications and information systems, which have evolved separately over the years.ObjectiveThis paper proposes a solution for extending the SOA/Web Services Platform Architecture (WSPA) with support for business events and EDA concepts. Our solution enables services to act as event producers and event consumers. It also enables event-driven service orchestrations in business processes.MethodBased on a comparison of SOA and EDA, we have identified and designed the required extensions to enable support for events and event-driven process orchestration in WSPA.ResultsWe propose specific extensions to WSDL and BPEL, and a flexible XML representation of the event payload data. We introduce event sinks, sources, and triggers to WSDL. We extend BPEL with new activities to trigger and catch events, and extend fault and event handlers, variables, and correlation properties to accommodate events.ConclusionAs a proof-of-concept, we have developed a prototype implementation and assessed the extensions on three pilot projects. We have shown that our proposed extensions work on real projects and that combining event-driven and service-oriented semantics makes sense in many business applications and can considerably reduce the development effort.     

An evaluation framework for deploying Web Services in the next generation manufacturing enterprise

In today's competitive manufacturing environment, the ability to effectively and efficiently manage the flow of information is a vital competency. Manufacturing enterprises must be able to integrate their internal business processes horizontally and vertically, and they are increasingly required to support federated business processes with other members of their respective virtual value chains. Web Services, an emerging form of service-oriented architecture for distributed computing, have the potential to serve as a key enabling technology to support these requirements. Leveraging the inherent interoperability of Internet and Worldwide Web technologies, they enable cooperative processing across heterogeneous computing environments. This paper presents a framework for evaluating the viability of Web Services technologies to be incorporated into enterprise information architectures to support the business needs and requirements of next generation manufacturing enterprises. It examines economic, technical, and organizational contexts that will influence the ability of manufacturing-related enterprises to deploy advanced information architectures based on Web Services to support the complex business processes needed to collaborate with suppliers, customers, and other stakeholders in virtual enterprise environments.     

一种基于Web服务的RIA系统集成的应用

将Flex与Web服务相结合构建RIA（Rich Internet Application,富互联网应用）系统集成,利用Web服务将应用系统中业务流程逻辑封装为标准服务,通过服务的发布与发现机制,实现企业数据资源共享;利用加密算法对传输报文数字签名和加密;利用Flex为用户提供统一的富客户端用户界面,实现高度互动性和响应性的客户端,丰富用户体验;利用模块Modules方式、导航方式、动态加载组件方式,组件重用方式等重构Flex表示层,提高系统性能,并与J2EE相整合,验证Flex与Web服务相结合构建RIA系统集成的可行性,合理性。     

A semantical framework to engineering WSBPEL processes

Web services promise the interoperability of various applications running on heterogeneous platforms over the Internet, and are gaining more and more attention. Web service composition refers to the process of combining Web services to provide value-added services, which has received much interest in supporting enterprize application integration. Industry standards for Web Service composition, such as WSBPEL, provide the notation and additional control mechanisms for the execution of business processes in Web service collaborations. However, these standards do not provide support for checking interesting properties related to Web Service and process behavior. In an attempt to fill this gap, we describe a formalization of WSBPEL business processes, that adds communications semantics to the specifications of interacting Web services, and uses a formal logic to model their dynamic behavior, which enables their formal analysis and the inference of relevant properties of the systems being built.     

基于语义的业务流程一致性评价

随着Internet技术的不断发展,电子商务中的B2B应用也逐渐成为企业之间进行业务活动的主要依托技术,企业定义了自己的业务流程,双方业务流程的一致性在业务伙伴间的协作中扮演着非常重要的角色。目前,已经有诸如BPEL4WS和ebXML这样的电子商务技术能够使得企业在业务流程级进行协作,但这些技术均是基于XML技术,所提供的功能主要是语法上的,很少涉及他们的业务流程的一致性评价。为此,扩展了ebXML框架以支持业务流程的一致性评价,设计了一个一致性评价代理来执行客户企业的需要,并搜寻ebXML注册中心的潜在伙伴的业务信息,基于良好定义的一致性标准测试他们与客户企业业务流程间的一致性,最后提交一个评价结果给客户企业。通过这样的过程,客户企业能够找到合适的业务伙伴。而且,采用了语义网的方法,使得评价的结果更加准确。     

Modeling business processes with BPEL4WS

Business Process Execution Language for Web Services (BPEL4WS) allows defining both, business processes that make use of Web services, and business processes that externalize their functionality as Web services. This short paper introduces the basic language elements of BPEL4WS using a simple example. The concepts underlying the language are briefly explained: establishing bilateral partnerships, correlating messages and processes, defining the order of the activities of a business process, event handling, handling exceptions via long-running transactions, and the usage of BPEL4WS in pure B2B scenarios. The paper finishes off by presenting the resulting application structure and the resulting economical implications.     

The effect of text and background colour on visual search of Web pages

Usability and visual impact in Web pages are not necessarily compatible ideals. This paper investigates the effect of colour on the presentation of information in a navigation bar, and aims to contribute towards design guidelines for the use of colour on the Web. We studied the effect of the combination of text and background colour on visual search performance and subjective preference. Twenty-nine participants carried out a visual search task using mock Web pages. Analysis showed that higher contrasts between text and background colour led to faster searching and were rated more favourably. The results are discussed in terms of visual search processes and design recommendations are given.     

Experiences developing architectures for realizing thin‐client diagram editing tools

Diagram‐centric applications such as software design tools, project planning tools and business process modelling tools are usually ‘thick‐client’ applications running as stand‐alone desktop applications. There are several advantages to providing such design tools as Web‐based or even PDA‐ and mobile‐phone‐based applications. These include ease of access and upgrade, provision of collaborative work support and Web‐based integration with other applications. However, building such thin‐client diagram editing tools is very challenging. We have developed several thin‐client diagram editing applications realized as a set of plug‐in extensions to a meta‐tool for visual design environment development. In this paper, we discuss key user interaction and software architecture issues, illustrate examples of interacting with our thin‐client diagram editing tools, describe our design and implementation approaches, and present the results of several different evaluations of the resultant applications. Our experiences will be useful for those interested in developing their own thin‐client diagram editing architectures and applications. Copyright © 2007 John Wiley & Sons, Ltd.     

语义标记Petri网的组合Web服务建模与验证(英文)

随着Web服务组合的发展,整合业务过程成为可能。组合Web服务可以被看作是基于过程的工作流。由于死锁、不安全和不可达等流的设计错误会影响组合Web服务的有效执行,因此这些错误应在组合Web服务执行前被检测出并修改。提出了基于语义标记Petri网的组合Web服务建模与验证方法。首先提出语义标记Petri网(SaPNs),并给出其语义;用受限描述逻辑tableau算法获得组合Web服务;使用SaPNs描述组合Web服务及其组成部分;最后,使用基于SaPNs的分析方法验证了组合Web服务。使用该方法在开放的Internet环境下可以获得满足客户需求的、可靠的组合Web服务。     

A case study in systematic hypermedia design

Hypermedia structuring and navigation requires design methodologies different from those developed for standard information systems. This case study details our successful application of relationship management methodology (RMM), a hypermedia systems analysis and design methodology, to ACM SIGLINK's LINKBase. LINKBase is a World Wide Web (WWW) application, which dynamically generates WWW pages from a relational database containing information about hypermedia-related events such as conferences, publications, authors, and sponsoring organizations. We describe our experience applying RMM in this case study, summarize design lessons we learned in the process, present extensions to RMM, discuss human–computer interaction (HCI) aspects of RMM, and ground our work in the hypermedia design and HCI literature. Our experiences should encourage hypermedia and WWW developers to utilize systematic design techniques to build highly usable and useful WWW applications.