ARIS Method Extension for Business-Driven SOA

Service-oriented architecture (SOA) promises making companies more flexible enabling them to react quickly to changing market conditions. To leverage those advantages, SOA must be integrated with other existing approaches like business process management and enterprise architecture management. The authors describe how they extended the enterprise architecture management and business process management modelling method ARIS. They first created a SOA meta model by abstracting from existing modelling methods as well as extracting expert knowledge through interviews. In a second step, they mapped the SOA meta model to ARIS to provide a concrete modelling language for service-oriented enterprises. The ARIS extension allows describing and governing service architectures, describing services, linking service development initiatives to projects and company strategy, and discovering services for business process automation.

Evaluating legacy assets in the context of migration to SOA

A key activity in the introduction of service oriented architecture (SOA) for an organization is to evaluate the suitability of existing assets for service orientation. We identify the core principles of SOA as the guide lines in evaluating the suitability of the existing assets. The existing metrics and guidelines that could be helpful in evaluating these principles are surveyed. This would benefit an organization in understanding the effort needed for migration and also to build proper services from the existing assets.

Services computing as the foundation of enterprise agility: Overview of recent advances and introduction to the special issue

The advancement of web services in the last few years has spurred a number of revolutionary concepts in information technology and management including service-oriented architectures, service-oriented computing, and services science, management and engineering, which can be collectively called as “services computing.” Services computing is a new research field that goes beyond traditional computing disciplines as it includes not only architectural, programming, deployment, and other engineering issues, but also management issues such as business component modeling, business process design, and service delivery. In this paper, we provide an overview of emerging research concepts in services computing without attempting to unify them as it will take sometime for the field to become mature. In addition, we take a position that the ultimate goal of services computing is to create the necessary technological and managerial foundation to support enterprise agility. In this short paper, we give an overview of services computing, describe its relationship to enterprise agility, and discuss basic technical and managerial issues. Finally, we introduce the papers that are published in this special issue.

Usage-based dynamic pricing of Web services for optimizing resource allocation

Web services technology is becoming an important technological trend in Web application development and integration. Based on open standards, such as SOAP, WSDL, and UDDI, Web services allow Web-based applications to communicate with each other through standardized XML messaging and to form loosely coupled distributed systems. Although the open feature of Web services benefits service providers in servicing consumers, the unlimited computing resources access of Web services to network bandwidth, storage throughput, and CPU time may lead to overexploitation of the resources when applications based on the Web services technology are widely accepted. Therefore, it is critical to optimize the operation of Web services, subject to the QoS requirements of service requests, to assure the total benefits of the service providers and the service consumers. This paper proposes a usage-based dynamic pricing approach to optimizing resource allocation of Web services in the principle of economics, and reports on a pilot implementation demonstrating the technical feasibility of the proposed approach.

Designing a novel high-performance FPGA architecture for data intensive applications

A wide variety of real-time applications (e.g. multimedia, communication, etc.) require implementations that meet tight timing constraints. This work introduces novel high-performance FPGA architecture capable of implementing efficiently any time critical application. The fundamental contribution of the proposed reconfigurable architecture is the design of a highly efficient (performance and power consumption) interconnection structure, taking into consideration the statistical and spatial data extracted from applications, which are implemented on Virtex FPGAs. The derived architecture is software-supported by the MEANDER design framework. Using a number of real-time applications, extensive comparison study in terms of several design parameters proves the effectiveness of the proposed architecture against to Virtex one. More specifically, the proposed architecture achieves performance improvement and power savings up to 20 and 16%, respectively. Moreover, compared to a Virtex architecture with same power budget, our architecture achieves performance improvement by 42%.

Personalised e-learning through an educational virtual reality game using Web services

This paper describes how a personalised educational game architecture has been used in conjunction with Web services to provide remote access to the system. The educational game is a virtual reality adventure game that performs affective user modelling by measuring emotional characteristics of users. Virtual reality (VR) games are so popular among children and adolescents that can be used for the purposes of educational software to render it more attractive and motivating. The benefits of such an application can be maximised if it is available over the Web. Software applications that operate over the Web are targeted to a wide range of users. Hence they need a high degree of adaptivity and dynamic individualisation to each user that interacts with the application. This should include the students’ emotional state that affects their learning. However, the environment of a Web-based VR-game that performs user modelling is so demanding that the technology of Web services is necessary for its effective operation and interoperability. Moreover, reusability may be achieved for the user modelling component.

A Service Oriented Architecture-based Approach for Interdomain Optical Network Services

This work presents a service-oriented architecture for interdomain service provisioning in optical networks. The architecture introduces a service layer that concentrates all the interactions among domains necessary for service provisioning. A service layer is an alternative to the GMPLS (Generalized Multiprotocol Label Switching) architecture, but without a rigid control plane as found in GMPLS. We start by defining a set of basic services to provide single end-to-end (e2e) interdomain connections. Then, more sophisticated services are created through the composition of these basic services. The interdomain Optical VPN (Virtual Private Network) service is considered in order to illustrate the composition of services. A prototype of the architecture was designed and implemented using Web services as the main technology. The architecture was evaluated in terms of speed, scalability, and bandwidth consumption necessary to establish e2e interdomain connections and Optical VPNs.

Evaluating pattern conformance of UML models: a divide-and-conquer approach and case studies

A design pattern is realized in various forms depending on the context of the applications. There has been intensive research on detecting pattern instances in models and in implementations. However, little work addresses variations of pattern realization. This paper describes an approach for evaluating conformance of pattern variations. This approach uses a divide-and-conquer strategy to evaluate the structural conformance of a UML class diagram to the solution of a design pattern. A design pattern is specified in an extension of the UML that defines the pattern in terms of roles. To demonstrate the approach, we use the Visitor pattern and two case studies of a price calculator and a word processor. We also present a prototype tool that supports the approach.

Interacting with mobile services: an evaluation of camera-phones and visual tags

We present a study of using camera-phones and visual-tags to access mobile services. Firstly, a user-experience study is described in which participants were both observed learning to interact with a prototype mobile service and interviewed about their experiences. Secondly, a pointing-device task is presented in which quantitative data was gathered regarding the speed and accuracy with which participants aimed and clicked on visual-tags using camera-phones. We found that participants’ attitudes to visual-tag-based applications were broadly positive, although they had several important reservations about camera-phone technology more generally. Data from our pointing-device task demonstrated that novice users were able to aim and click on visual-tags quickly (well under 3 s per pointing-device trial on average) and accurately (almost all meeting our defined speed/accuracy tradeoff of 6% error-rate). Based on our findings, design lessons for camera-phone and visual-tag applications are presented.

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Acquiring and incorporating state-dependent timing requirements

Some real-time systems are designed to deliver services to objects that are controlled by external sources. Their services must be delivered on a timely basis, and the system fails when some services are delivered too late. In general, the timing requirements of the system may change when the states of the objects monitored by the system change. Such a system may fail if the timing requirements which it is designed to meet are erroneous. It may underutilize resources and consequently be costly or unreliable if the requirements are too stringent. Hence, one must identify how changes in object states call for changes in system requirements and how these changes should be incorporated into the design and implementation of the system. This paper first describes a methodology to determine timing requirements and to take into account requirement changes at runtime. The method is based on several timing requirement determination schemes. Simulation data show that these schemes are effective for applications such as mobile IP hand-offs. The paper then discusses how to incorporate this methodology in the system architecture and in the development process.

Trust management towards service-oriented applications

In service-oriented computing (SOC) environments, service clients interact with service providers for services or transactions. From the point view of service clients, the trust status of a service provider is a critical issue to consider, particularly when the service provider is unknown to them. Typically, the trust evaluation is based on the feedback on the service quality provided by service clients. In this paper, we first present a trust management framework that is event-driven and rule-based. In this framework, trust computation is based on formulae. But rules are defined to determine which formula to use and what arguments to use, according to the event occurred during the transaction or service. In addition, we propose some trust evaluation metrics and a formula for trust computation. The formula is designed to be adaptable to different application domains by setting suitable arguments. Particularly, the proposed model addresses the incremental characteristics of trust establishment process. Furthermore, we propose a fuzzy logic based approach for determining reputation ranks that particularly differentiates new service providers and old (long-existing) ones. This is further incentive to new service providers and penalize poor quality services from service providers. Finally, a set of empirical studies has been conducted to study the properties of the proposed approaches, and the method to control the trust changes in both trust increment and decrement cases. The proposed framework is adaptable for different domains and complex trust evaluation systems.

Defining the grid: a snapshot on the current view

The term “Grid” was introduced in early 1998 with the launch of the book “The Grid. Blueprint for a new computing infrastructure”. Since that time many technological changes have occurred in both hardware and software. One of the most important ones seems to be the wide acceptance of Web services. Although the basic Grid idea has not changed much in the last decade, many people have different ideas about what a Grid really is. In the following article we report on a survey where we invited many people in the field of Grid computing to give us their current understanding.

Information systems design: through adaptivity to ubiquity

In a globalised economy the accessibility of services becomes increasingly important for businesses. This has led to a demand that information systems should be ubiquitous in the sense that they are available to all users under all circumstances, everywhere and at all times, and independent of the access devices and channels used. The authors believe the key to meeting that demand is existence of an omnipresent media of interaction and existence of information systems that within that media adapt themselves to context parameters at run-time. The World Wide Web is considered as that omnipresent media. Thus, the task is left to design adaptive information systems in a way that avoids unnecessary replication. In this article it will be shown how context parameters can be utilised to enable system adaptivity. The latter is supposed to increase usability and targets the quality of use, the content, and the functionality. We propose using an algebraic approach that aids in providing the leanest appropriate interface via user typing and story boarding. Our approach furthermore limits the content delivered to a user to the amount that can be dealt with in a usage scenario. The latter is based on defining hyphenation points within the content.

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Agent-based multimedia presentation and adaptation service

In this paper, we aim to provide adaptive multimedia services especially video ones to end-users in an efficient and secure manner. Users moving outside the office should be able to maintain an office-like environment at their current locations. First, the agents within our proposed architecture negotiate the different communication and interaction factors autonomously and dynamically. Moreover, we needed to develop a user agent in addition to service and system agents that could negotiate the requirements and capabilities at run time to furnish best possible service results. Thus we designed and integrated a video indexing and key framing service within our overall agent-based architecture. We integrated this video indexing and content-based analysis service to adapt the video content according to run time conditions. We designed a video XML schema to validate the media content out of this multimedia service according to specific requirements and features, as we will describe later.

Supporting ordering and consistency in a distributed Event Heap for Ubiquitous Computing

The Stanford Event Heap has been shown to provide appropriate support for constructing interactive workspace applications. Given this success it is natural to consider the Event Heap as a platform to support other classes of Ubiquitous Computing applications. In this paper we argue that the distributed, spontaneous nature of these applications places additional demands on the Event Heap that require extensions to both the engineering and API. Suitable extensions are described and their use to support a typical Ubicomp application is discussed.

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Multimodal support to group dynamics

The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole. A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.

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Automatically wrapping legacy software into services: A grid case study

The computational grid is rapidly evolving into a service-oriented computing infrastructure that facilitates resource sharing for solving large-scale data and computationally intensive problems. Peer-to-peer (P2P) systems have emerged as an infrastructure enabling technologies for enhanced scalability and reliability in file sharing and content distribution. It is envisioned that P2P enabled service-oriented grid systems would virtualize various resources as services with high scalability and reliability. Many legacy software resources exist nowadays, but making them grid aware services for effective resource sharing has become an issue of vital importance. This paper presents GSLab, a toolkit for automatically wrapping legacy software into services that can be published, discovered and reused in grid environments. GSLab employs Sun Grid Engine (SGE) to enhance its performance in execution of wrapped services. Using GSLab, we have automatically wrapped a legacy computer animation rendering code written in C as a service that can be discovered and accessed in a SGE environment. The evaluation results show that the performance of GSLab improves with an increase in the number of computing nodes involved.

Challenges and opportunities in collaborative business process management: Overview of recent advances and introduction to the special issue

Modern business process management expands to cover the partner organisations’ business processes across organisational boundaries, and thereby supports organisations to coordinate the flow of information among organisations and link their business processes. With collaborative business processes, organisations can create dynamic and flexible collaborations to synergically adapt to the changing conditions, and stay competitive in the global market. Due to its significant potential and value, collaborative business processes are now turning to be an important issue of contemporary business process management, and attracts lots of attention and efforts from both academic and industry sides. In this paper, we review the development of B2B collaboration and collaborative business processes, provide an overview of related issues in managing collaborative business processes, and discuss some emerging technologies and their relationships to collaborative business processes. Finally, we introduce the papers that are published in this special issue.

Methods for quantitative usability requirements: a case study on the development of the user interface of a mobile phone

Quantitative usability requirements are a critical but challenging, and hence an often neglected aspect of a usability engineering process. A case study is described where quantitative usability requirements played a key role in the development of a new user interface of a mobile phone. Within the practical constraints of the project, existing methods for determining usability requirements and evaluating the extent to which these are met, could not be applied as such, therefore tailored methods had to be developed. These methods and their applications are discussed.

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