Composing Model Transformations at Runtime: an approach for adapting Component-based User Interfaces

Nowadays, large part of the efforts in software development are focused on achieving systems with an as high as possible level of adaptation. With the traditional technique of model-driven development this can be largely accomplished. The inconvenience of these techniques however, is that the models are usually manipulated at design-time by means of fixed transformation. Furthermore, the transformations that manipulate these models cannot change dynamically according to the current execution context. This paper presents a transformation pattern aimed to adapt architectural models at runtime, this means that these models may change dynamically at runtime. The transformations that produce this model adaptation are not fixed, but dynamically composed by selecting the most appropriate set of rules from those available in a repository. As an example scenario for the application of these transformations, we chose architectural models representing component-based UIs

06291 Abstracts Collection -- The Role of Business Processes in Service-Oriented Architectures

The Dagstuhl seminar on emph{The Role of Business Processes in Service Oriented Architectures} (Seminar 06291) took place in July 2006 (16.07.2006-21.07.2006 to be precise). The seminar was attended by more than 40 experts from both academia and industry. Unlike most Dagstuhl seminars there was a high participation from industry (in particular from organizations developing software, e.g., IBM, SAP, Microsoft, Google, etc.). The focal point of the seminar was the marriage of business processes and service oriented architectures. This was reflected by the topics selected by the participants and their background

Service Composition for IP Smart Object using Realtime Web Protocols: Concept and Research Challenges

The Internet of Things (IoT) refers to a world-wide network of interconnected physical things using standardized communication protocols. Recent development of Internet Protocol (IP) stacks for resource-constrained devices unveils a possibility for the future IoT based on the stable and scalable IP technology much like today's Internet of computers. One important question remains: how can data and events (denoted as services) introduced by a variety of IP networked things be exchanged and aggregated e ciently in various application domains. Because the true value of IoT lies in the interaction of several services from physical things, answers to this question are essential to support a rapid creation of new IoT smart and ubiquitous applications. The problem is known as service composition. This article explains the practicability of the future full-IP IoT with realtime Web protocols to formally state the problem of service composition for IP smart objects, provides literature review, and discusses its research challenges

Automated synthesis of local time requirement for service composition

National Research Foundation (NRF) Singapore ANR-NRF French-Singaporean research program ProMi

Bridging the digital divide for e-learning students through adaptive VLEs

Virtual Learning Environments (VLEs) are required to be highly effective and easy to use as they serve as the primary institutional portal between students and academics. There are currently a number of challenges that are caused due to the modernized digital divide, with a significant limitation being the inability of information systems to adapt to the users' technological platform, broadband quality and device in use to access the online system. This paper focuses on the limitations that students encounter when accessing VLEs within Higher Educational Institutes (HEIs). This research aims to primarily review and provide critical analysis of current VLE frameworks, as well as assess restrictions based on several demographics including content adaptation and technical aspects. An algorithmic system is developed to analyze students' individualistic needs, undertake adaption and personalization of the VLE, and hence ensure consistent and efficient access to academic web resources and functionalitie

MANAGING QUERY AND UPDATE TRANSACTIONS UNDER QUALITY CONTRACTS IN WEB-DATABASES

In modern Web-database systems, users typically perform read-only queries, whereas all write-only data updates are performed in the background, concurrently with queries.For most of these services to be successful and their users to be kept satisfied, two criteria need to be met: user requests must be answered in a timely fashion and must return fresh data. This is relatively easy when the system is lightly loaded and, as such, both queries and updates can be executed quickly. However, this goal becomes practically hard to achieve in real systems due to the high volumes of queries and updates, especially in periods of flash crowds. In this work, we argue it is beneficial to allow users to specify their preferences and let the system optimize towards satisfying user preferences, instead of simply improving the average case. We believe that this user-centric approach will empower the system to gracefully deal with a broader spectrum of workloads.Towards user-centric web-databases, we propose a Quality Contracts framework to help users express their preferences over multiple quality specifications. Moreover, we propose a suite of algorithms to effectively perform load balancing and scheduling for both queries and updates according to user preferences. We evaluate the proposed framework and algorithms through a simulation with real traces from disk accesses and from a stock information website. Finally, to increase the applicability of Quality Contracts enhanced Web-database systems, we propose an algorithm to help users adapt to the Web-database system behavior and maximize their query success ratio

Context Verification and Adaptation in Web Service Composition

Automatic web-service composition aims at automating the design of an appropriate combination of existing web services to achieve a global goal. Most proposed AWSC approaches only consider input/output parameters and quality features of services. However, most real-world web services have applicable conditions and require constraints to be considered according to the execution context of composite services. Constraint verification has a significant impact on the composition and execution of composite services. In particular, runtime verification of service constraints can result in the failure of the execution of composite services and eventually waste computational resources and may incur monetary costs. In addition, traditional adaptation approaches for web service composition consider recovery in case of failure when a service becomes unavailable. They do not take into account changes and limitations in service execution environment which potentially can affect the execution of a wide range of services. Externally-defined constraints are likely to be defined and become or cease to be applicable after the composite service has been deployed. In this thesis, we propose a novel approach to model and verify different types of constraints inside composite services. We not only consider input/output parameters but also the values that can be assigned to parameters during design and execution of composite services. In addition, we provide novel failure recovery and adaptation approaches for different types of constraints according to the execution context of composite services. In our solution, we develop a new structure including alternative composite services to recover broken composite services and adapt to external constraints. We finally propose a brokerage architecture including all proposed approaches for constraint-aware service composition and adaptation

Requirements model driven adaption and evolution of Internetware

Today’s software systems need to support complex business operations and processes. The development of the web-based software systems has been pushing up the limits of traditional software engineering methodologies and technologies as they are required to be used and updated almost real-time, so that users can interact and share the same applications over the internet as needed. These applications have to adapt quickly to the diversified and dynamic changing requirements in the physical, technological, economical and social environments. As a consequence, we are expecting a major paradigm shift in software engineering to reflect such changes in computing environment in order to better address the fundamental needs of organisations in this new era. Existing software technologies, such as model driven development, business process engineering, online (re-)configuration, composition and adaptation of managerial functionalities are being repurposed to reduce the time taken for software development by reusing software codes. The ability to dynamically combine contents from numerous web sites and local resources, and the ability to instantly publish services worldwide have opened up entirely new possibilities for software development. In retrospect to the ten years applied research on Internetware, we have witnessed such a paradigm shift, which brings about many changes to the developmental experience of conventional web applications. Several related technologies, such as cloud computing, service computing, cyber-physical systems and social computing, have converged to address this emerging issue with emphasis on different aspects. In this paper, we first outline the requirements that the Internetware software paradigm should meet to excel at web application adaptation; we then propose a requirement model driven method for adaptive and evolutionary applications; and we report our experiences and case studies of applying it to an enterprise information system. Our goal is to provide high-level guidelines to researchers and practitioners to meet the challenges of building adaptive industrial-strength applications with the spectrum of processes, techniques and facilities provided within the Internetware paradigm

Context-Sensitive Authorization in Interaction Patterns

Main requirement of recent computing environments, like mobile and then ubiquitous computing, is to adapt applications to context. On the other hand, access control generally trust users once they have authenticated, despite the fact that they may reach unauthorized situations. We analyse how dynamic information can be used to improve security in the authorization process, and what are the implications when applied to interaction patterns. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS)