A Framework for Evaluating Model-Driven Self-adaptive Software Systems

In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately in order to specify the design of the self-adaptive applications, and, at the same time, support software with adaptability and context-awareness. This research studies the development methodologies that employ the principles of model-driven development in building self-adaptive software systems. To this aim, this article proposes an evaluation framework for analysing and evaluating the features of model-driven approaches and their ability to support software with self-adaptability and dependability in highly dynamic contextual environment. Such evaluation framework can facilitate the software developers on selecting a development methodology that suits their software requirements and reduces the development effort of building self-adaptive software systems. This study highlights the major drawbacks of the propped model-driven approaches in the related works, and emphasise on considering the volatile aspects of self-adaptive software in the analysis, design and implementation phases of the development methodologies. In addition, we argue that the development methodologies should leave the selection of modelling languages and modelling tools to the software developers.Comment: model-driven architecture, COP, AOP, component composition, self-adaptive application, context oriented software developmen

A Framework for Evaluating Model-Driven Self-adaptive Software Systems

In the last few years, Model Driven Development (MDD), Component-based Software Development (CBSD), and context-oriented software have become interesting alternatives for the design and construction of self-adaptive software systems. In general, the ultimate goal of these technologies is to be able to reduce development costs and effort, while improving the modularity, flexibility, adaptability, and reliability of software systems. An analysis of these technologies shows them all to include the principle of the separation of concerns, and their further integration is a key factor to obtaining high-quality and self-adaptable software systems. Each technology identifies different concerns and deals with them separately in order to specify the design of the self-adaptive applications, and, at the same time, support software with adaptability and context-awareness. This research studies the development methodologies that employ the principles of model-driven development in building self-adaptive software systems. To this aim, this article proposes an evaluation framework for analysing and evaluating the features of model-driven approaches and their ability to support software with self-adaptability and dependability in highly dynamic contextual environment. Such evaluation framework can facilitate the software developers on selecting a development methodology that suits their software requirements and reduces the development effort of building self-adaptive software systems. This study highlights the major drawbacks of the propped model-driven approaches in the related works, and emphasise on considering the volatile aspects of self-adaptive software in the analysis, design and implementation phases of the development methodologies. In addition, we argue that the development methodologies should leave the selection of modelling languages and modelling tools to the software developers

How Can Personality Influence Perception on Security of Context-Aware Applications?

[Context and Motivation] Our lives are being transformed by context-aware software applications with important social, environmental, and economic implications. [Question/Problem] Experts recognized that quality attributes, e.g. security, are the cornerstone to get healthy social implications of these applications. However, do end-users (service consumers) perceive these attributes as so important? [Methodology] To answer this question, we designed a survey, to understand how end-users perceive security of context-aware software applications and how the users’ personality traits might influence their perceptions. To this end, we did a web-based survey that embeds two animated-demonstration videos in order to present i) the functionality of a context-aware mobile app, and ii) some vulnerabilities of the mobile app. It involved 48 subjects divided in two groups: subjects with software engineering (SE) background (Group A) and subjects without any SE background (Group B). [Results] Our study found that the importance of confidentiality and integrity is more clearly perceived by subjects with SE backgrounds (Group A). Accountability is more difficult to be perceived by subjects. And this difficulty can be even more pronounced for subjects without any SE background (Group B). Our findings suggest that importance preferences on security are influenced by personality types. For instance, open-minded people have a higher propensity to perceive the importance of confidentiality and integrity. Whilst, people with a high level of agreeableness hold quite different perceptions regarding the importance of authenticity and accountability. Analyzing the level of association between personality and the perceived importance on security, we found that the importance perceptions on confidentiality are influenced by the personality of subjects from Group B. And, the changes (positive an negative) in the importance perception on confidentiality are very strongly influenced by personality, even more so by the personality of subjects from Group B.</p

Remote service discovery and control for ubiquitous service environments in next-generation networks

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 201

Remote service discovery and control for ubiquitous service environments in next-generation networks

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 201

Video Quality Prediction for Video over Wireless Access Networks (UMTS and WLAN)

Transmission of video content over wireless access networks (in particular, Wireless Local Area Networks (WLAN) and Third Generation Universal Mobile Telecommunication System (3G UMTS)) is growing exponentially and gaining popularity, and is predicted to expose new revenue streams for mobile network operators. However, the success of these video applications over wireless access networks very much depend on meeting the user’s Quality of Service (QoS) requirements. Thus, it is highly desirable to be able to predict and, if appropriate, to control video quality to meet user’s QoS requirements. Video quality is affected by distortions caused by the encoder and the wireless access network. The impact of these distortions is content dependent, but this feature has not been widely used in existing video quality prediction models. The main aim of the project is the development of novel and efficient models for video quality prediction in a non-intrusive way for low bitrate and resolution videos and to demonstrate their application in QoS-driven adaptation schemes for mobile video streaming applications. This led to five main contributions of the thesis as follows:(1) A thorough understanding of the relationships between video quality, wireless access network (UMTS and WLAN) parameters (e.g. packet/block loss, mean burst length and link bandwidth), encoder parameters (e.g. sender bitrate, frame rate) and content type is provided. An understanding of the relationships and interactions between them and their impact on video quality is important as it provides a basis for the development of non-intrusive video quality prediction models.(2) A new content classification method was proposed based on statistical tools as content type was found to be the most important parameter. (3) Efficient regression-based and artificial neural network-based learning models were developed for video quality prediction over WLAN and UMTS access networks. The models are light weight (can be implemented in real time monitoring), provide a measure for user perceived quality, without time consuming subjective tests. The models have potential applications in several other areas, including QoS control and optimization in network planning and content provisioning for network/service providers.(4) The applications of the proposed regression-based models were investigated in (i) optimization of content provisioning and network resource utilization and (ii) A new fuzzy sender bitrate adaptation scheme was presented at the sender side over WLAN and UMTS access networks. (5) Finally, Internet-based subjective tests that captured distortions caused by the encoder and the wireless access network for different types of contents were designed. The database of subjective results has been made available to research community as there is a lack of subjective video quality assessment databases.Partially sponsored by EU FP7 ADAMANTIUM Project (EU Contract 214751

A conceptual model of an access-technology-agnostic delivery mechanism for ICT4D services

Information and Communication Technology for Development (ICT4D) is an emerging research area that is concerned with the beneficial applications of Information and Communications Technology (ICT) to achieve developmental goals. ICT4D is thus concerned with designing and developing innovative technologies for resource-constrained environments for applications in key areas of social development such as health, agriculture and education. The ICT4D initiatives, therefore, are driving three main tasks, namely developing the required infrastructure (connectivity, electricity and computing devices) sustainably, building the required ICT human capacity, and providing access to digital content and services. Each of these three main thrusts necessitates innovation. This study addresses the evident lack of delivery mechanisms to facilitate access to digital content and services to end-users through the technologies that these end-users already possess. This lack of innovative delivery mechanisms is both an impediment to achieving equitable access to digital content and service and an opportunity to innovate. Therefore, drawing from the theoretical background of ICT4D, this study develops a set of technical and socio-technical requirements that the missing delivery mechanisms should satisfy. The study also explores the Service Delivery Platform (SDP) concept as a technically viable basis for the required delivery mechanisms. The study then develops a conceptual model of an Access-Technology-Agnostic Delivery Mechanism as a possible delivery mechanism that facilitates equitable access to digital content and services within an ICT4D context. The relevance of the conceptual model is established and, through a prototype implementation, the technical feasibility and utility of the conceptual model is demonstrated. The conceptual model is demonstrated through a proof of concept implementation using standards-based open source technologies. The proof of concept clearly demonstrates that the access-technology-agnostic delivery of digital content and services is achievable, thus making the same service accessible through different access technologies. In developing the Access-Technology-Agnostic Delivery Mechanism, this study contributes through innovation to providing access to digital content and services in an access-technology-agnostic manner