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33
Adaptive service composition in flexible processes
- IEEE TRANS. SOFTWARE ENG
, 2007
"... In advanced service oriented systems, complex applications, described as abstract business processes, can be executed by invoking a number of available Web services. End users can specify different preferences and constraints and service selection can be performed dynamically identifying the best s ..."
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Cited by 141 (5 self)
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In advanced service oriented systems, complex applications, described as abstract business processes, can be executed by invoking a number of available Web services. End users can specify different preferences and constraints and service selection can be performed dynamically identifying the best set of services available at runtime. In this paper, we introduce a new modeling approach to the Web service selection problem that is particularly effective for large processes and when QoS constraints are severe. In the model, the Web service selection problem is formalized as a mixed integer linear programming problem, loops peeling is adopted in the optimization, and constraints posed by stateful Web services are considered. Moreover, negotiation techniques are exploited to identify a feasible solution of the problem, if one does not exist. Experimental results compare our method with other solutions proposed in the literature and demonstrate the effectiveness of our approach toward the identification of an optimal solution to the QoS constrained Web service selection problem.
A Survey of Context Data Distribution for Mobile Ubiquitous Systems
, 2013
"... The capacity to gather and timely deliver to the service level any relevant information that can characterize service-provisioning environment, such as computing resources/capabilities, physical device location, user preferences, and time constraints, usually defined as context-awareness, is widely ..."
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Cited by 23 (0 self)
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The capacity to gather and timely deliver to the service level any relevant information that can characterize service-provisioning environment, such as computing resources/capabilities, physical device location, user preferences, and time constraints, usually defined as context-awareness, is widely recognized as a core function for the development of modern ubiquitous and mobile systems. Much work has been done to enable contextawareness and to ease the diffusion of context-aware services; at the same time, several middleware solutions have been designed to transparently implement context management and provisioning in the mobile system. However, to the best of our knowledge, an in-depth analysis of the context data distribution, namely the function in charge of distributing context data to interested entities, is still missing. Starting from the core assumption that only effective and efficient context data distribution can pave the way to the deployment of truly context-aware services, this paper aims at putting together current research efforts to derive an original and holistic view of the existing literature. We present a unified architectural model and a new taxonomy for context data distribution, by considering and comparing a large number of solutions. Finally, based on our analysis, we
Bridging Existing Web Modeling Languages to Model-Driven Engineering: A Metamodel for WebML
- Proc. Second Int’l Workshop Model- Driven Web Eng
, 2006
"... Metamodels are a prerequisite for model-driven engineering (MDE) in general and consequently for model-driven web engineering in particular. Various modeling languages, just as in the web engineering field, however, are not based on metamodels and standards but instead define proprietary languages r ..."
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Cited by 16 (5 self)
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Metamodels are a prerequisite for model-driven engineering (MDE) in general and consequently for model-driven web engineering in particular. Various modeling languages, just as in the web engineering field, however, are not based on metamodels and standards but instead define proprietary languages rather focused on notational aspects. Thus, MDE techniques and tools can not be deployed for such languages. The WebML web modeling language is one example that does not yet rely on an explicit metamodel. Instead, it is implicitly defined within the accompanying tool in terms of a document type definition (DTD), i.e., a grammar-like textual definition for specifying the structure of XML documents. Code generation then has to rely on XSLT-based model-to-code transformations. In this paper, we propose a metamodel for WebML which is based on the Meta Object Facility (MOF). To establish such a metamodel a semi-automatic approach is provided that allows to generate MOF-based metamodels from DTDs. The metamodel for WebML accomplishes the following aims: First, it represents an initial step towards a transition to employing MDE techniques (e.g., model transformations or language extensions through profiles) within the WebML design methodology. Second, it represents an important step towards a common metamodel for Web modeling. Third, the provision of a MOF-based metamodel ensures interoperability with other MDE tools.
Model-driven Engineering of Active Context-Awareness
, 2005
"... Abstract. More and more Web users ask for contents and services highly tailored to their particular contexts of use. Especially due to the increasing affordability of new and powerful mobile communication devices, they also appreciate the availability of ubiquitous access, independent from the devic ..."
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Cited by 10 (2 self)
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Abstract. More and more Web users ask for contents and services highly tailored to their particular contexts of use. Especially due to the increasing affordability of new and powerful mobile communication devices, they also appreciate the availability of ubiquitous access, independent from the device actually in use. Due to such premises, traditional software design methods need to be extended, and new issues and requirements need to be addressed for supporting context-aware access to services and applications. In this paper we propose a model-driven approach towards adaptive, context-aware Web applications, accompanied by a general-purpose execution framework enabling active context-awareness. Whereas conventional adaptive hypermedia systems address the problem of adapting HTML pages in response to user-generated requests, in this work we especially stress the importance of user-independent, context-triggered adaptivity actions. This finally leads us to interpret the context as an active actor, operating independently from users during their navigations. 1
Aspect-oriented modeling of ubiquitous web applications: The aspectwebml approach
- In Proceddings of ECBS
, 2007
"... Ubiquitous web applications (UWA) are required to be customizable, meaning their services need to be adaptable towards the context of use, e.g., user, location, time, and device. Considering UWA’s from a software engineering point of view, a systematic development on basis of models is crucial. Curr ..."
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Cited by 9 (3 self)
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Ubiquitous web applications (UWA) are required to be customizable, meaning their services need to be adaptable towards the context of use, e.g., user, location, time, and device. Considering UWA’s from a software engineering point of view, a systematic development on basis of models is crucial. Current web modeling languages, however, often disregard the crosscutting nature of customization potentially affecting all parts of a web application, and often mingle core and customization functionality. This leads to inefficient development processes, high maintenance overheads, and a low potential for reuse. We regard customization as a crosscutting concern in the sense of the aspect-oriented paradigm. As a
Social Reference Model for Adaptive Web Learning
"... Abstract. In this paper, we describe the design steps of extending LAOS, a five-layer framework for generic adaptive web learning authoring, by adding a social layer to capture (and adapt) information from 1) collaborative authoring (i.e. editing the content of other learners, describing the content ..."
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Cited by 6 (0 self)
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Abstract. In this paper, we describe the design steps of extending LAOS, a five-layer framework for generic adaptive web learning authoring, by adding a social layer to capture (and adapt) information from 1) collaborative authoring (i.e. editing the content of other learners, describing the content using tags, rating the content, and commenting on the content, etc); and 2) authoring for collaboration (i.e., adding authors ’ activities, such as defining groups of authors, subscribing to other authors, etc). Moreover, the paper presents MOT 2.0, an adaptive E-learning 2.0 system, which is built on the proposed reference model, and finally, we report on our evaluations to validate the new Social Layer by comparing MOT 2.0 with its predecessor, MOT 1.0.
Xipho: Extending Tropos to engineer context-aware personal agents
- In Proceedings of the 13th International Conference on Autonomous Agents and Multi-Agent Systems
, 2014
"... ABSTRACT We introduce Xipho, an agent-oriented methodology for engineering context-aware personal agents (CPAs). Xipho extends Tropos to support CPA development. Xipho's steps span a CPA's requirements acquisition, design, and implementation. Importantly, we treat context as a cognitive n ..."
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Cited by 6 (4 self)
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ABSTRACT We introduce Xipho, an agent-oriented methodology for engineering context-aware personal agents (CPAs). Xipho extends Tropos to support CPA development. Xipho's steps span a CPA's requirements acquisition, design, and implementation. Importantly, we treat context as a cognitive notion and systematically relate it to other cognitive notions such as goals and plans. Xipho incorporates reusable components in a CPA's design and implementation to simplify the development process. We evaluate Xipho empirically, finding that Xipho reduces development time and effort, and improves the comprehensibility of CPA designs.
aspectUWA: Applying AspectOrientation to the Model-Driven Development of Ubiquitous web Applications, Student Extravaganza
- Int. Conf. on Aspect-Oriented Software Development: Poster Event
, 2006
"... With the emergence of mobile devices as new access channels to the Internet, we are now facing a new generation of Web applications, called ubiquitous Web applications (UWA). UWAs are characterized by the anytime/anywhere/anymedia paradigm [5], meaning that services are not exclusively accessed thro ..."
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Cited by 5 (3 self)
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With the emergence of mobile devices as new access channels to the Internet, we are now facing a new generation of Web applications, called ubiquitous Web applications (UWA). UWAs are characterized by the anytime/anywhere/anymedia paradigm [5], meaning that services are not exclusively accessed through traditional desktop PCs but through mobile devices with different capabilities, by users with various interests at anytime from anyplace around the globe. Services provided by UWAs are adapted to a certain context of use in order to preserve or even enhance their semantic value for users. Thus, knowing the context (e.g. user, location, time, device, etc.) and providing adaptation operations for Web objects (i.e. text, images, links, etc.) are the main prerequisites for customization of Web applications towards ubiquity. Thus customization denotes the mapping of the required adaptation of an application’s services with respect to its context
The impact of accessibility assessment in macro scale universal usability studies of the web
- In Proceedings of the 2008 international cross-disciplinary conference on Web accessibility, ACM
"... This paper presents a modelling framework, Web Interaction Environments, to express the synergies and differences of audiences, in order to study universal usability of the Web. Based on this framework, we have expressed the implicit model of WCAG and developed an experimental study to assess the We ..."
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Cited by 4 (1 self)
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This paper presents a modelling framework, Web Interaction Environments, to express the synergies and differences of audiences, in order to study universal usability of the Web. Based on this framework, we have expressed the implicit model of WCAG and developed an experimental study to assess the Web accessibility quality of Wikipedia at a macro scale. This has resulted on finding out that template mecha-nisms such as those provided by Wikipedia lower the burden of producing accessible contents, but provide no guarantee that hyperlinking to external websites maintain accessibil-ity quality. We discuss the black-boxed nature of guidelines such as WCAG and how formalising audiences helps leverag-ing universal usability studies of the Web at macro scales.
A Survey on Web Modeling Approaches for Ubiquitous Web Applications
"... Today’s web applications are full-fledged, complex software systems for which a methodologically sound engineering approach is crucial. Web engineering has emerged as an independent branch of software engineering and ”comprises the use of systematic and quantifiable approaches in order to accomplish ..."
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Cited by 4 (1 self)
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Today’s web applications are full-fledged, complex software systems for which a methodologically sound engineering approach is crucial. Web engineering has emerged as an independent branch of software engineering and ”comprises the use of systematic and quantifiable approaches in order to accomplish the specification, implementation, operation, and maintenance of high quality web applications ” [Kappel et al.
