Software-intensive systems operating in a shared environment must utilize a "request, acquire and release" protocol. In the popular client-server architecture resource-poor clients rely on servers for the needed capabilities. With mobile clients using wireless connectivity, the disparity in resource needs can force the consideration of adaptation by clients, leading to a strategy of self-reliance. Achieving self-reliance through adaptation becomes even more attractive in environments, which are dynamic and continually changing. A more comprehensive strategy is for the mobile client to recognize the changing resource levels and plan for any such degradation; that is, the applications in the mobile client need to adapt to the changing environment and availability of resources. Portable adaptation middleware that is sensitive to architecture and context changes in network operations is designed and implemented. The Adaptation Middleware not only provides the flexibility for the client applications to adapt to changing resources around them, but also to changing resource levels within the client applications. Further, the Adaptation Middleware imposes few changes on the structure of the client application. The Adaptation Middleware creates the adaptations; the client remains unaware and unconcerned with these adaptations. The Adaptation Middleware in this study also enables a more informative cost estimation with regard to applications such as mobile agents. A sample application developed using the Adaptation Middleware shows performance improvements in the range of 31% to 54%. A limited set of experiments show an average response time of 68 milliseconds, which seems acceptable for most applications. Further, the Adaptation Middleware permits increased stability for applications demonstrating demand levels subject to high uncertainty. / Master of Science

The research presented in this thesis covers two specific problems within the larger domain of cyber-physical algorithms for enhancing collaboration between one or more people. The two specific problems are 1) determining when people are going to arrive late to a meeting and 2) creating ad-hoc secure pairing protocols for short-range communication. The domain was broken down at opposite extremes in order to derive these problems to work on: 1) collaborations that are planned long in advance and deviations from the plan need to be detected and 2) collaborations that are not planned and need to be dynamically created and secured. Empirical results show the functionality and performance of user late arrival detection for planned collaborations and end-user authentication protocols for unplanned collaborations. / Master of Science

This dissertation is composed of research studies that contribute to three research areas including social context-aware computing, internal context-aware computing, and human behavioral data mining. In social context-aware computing, four studies are conducted. First, mobile phone user calling behavioral patterns are characterized in forms of randomness level where relationships among them are then identified. Next, a study is conducted to investigate the relationship between the calling behavior and organizational groups. Third, a method is presented to quantitatively define mobile social closeness and social groups, which are then used to identify social group sizes and scaling ratio. Last, based on the mobile social grouping framework, the significant role of social ties in communication patterns is revealed. In internal context-aware computing, two studies are conducted where the notions of internal context are intention and situation. For intentional context, the goal is to sense the intention of the user in placing calls. A model is thus presented for predicting future calls envisaged as a call predicted list (CPL), which makes use of call history to build a probabilistic model of calling behavior. As an incoming call predictor, CPL is a list of numbers/contacts that are the most likely to be the callers within the next hour(s), which is useful for scheduling and daily planning. As an outgoing call predictor, CPL is generated as a list of numbers/contacts that are the most likely to be dialed when the user attempts to make an outgoing call (e.g., by flipping open or unlocking the phone). This feature helps save time from having to search through a lengthy phone book. For situational context, a model is presented for sensing the user's situation (e.g., in a library, driving a car, etc.) based on embedded sensors. The sensed context is then used to switch the phone into a suitable alert mode accordingly (e.g., vibrate mode while in a library, handsfree mode while driving, etc.). Inferring (social and internal) context introduces a challenging research problem in human behavioral data mining. Context is determined by the current state of mind (internal), relationship (social), and surroundings (physical). Thus, the current state of context is important and can be derived from the recent behavior and pattern. In data mining research area, therefore, two frameworks are developed for detecting recent patterns, where one is a model-driven approach and the other is a data-driven approach.

M.Tech (Department of Information technology, Faculty of Applied and Computer Science), Vaal University of Technology. / The advancement of technology, particularly in the area of mobile computing, revolutionizes the way business is done in many industries such as the education sector, government sector, financial institutions, retail sector and the way people conduct their daily activities. The current technology provides influential tools for organisations and can significantly influence their operation, structure and approach. The development of mobile computing has created a new innovation for various industries by increasing the availability, frequency and speed of communication between the organisations and the individuals. However, users’ perceptions can play an important role towards the adoption of these new developments. The overriding purpose of this study was to investigate the users’ perceptions on the security of mobile computing in South Africa for adoption of e-applications. The literature review was concentrated on the process of progressive development occurring during the study. To accomplish that goal it became necessary to reach some essential objectives i.e. investigating the users’ perceptions models in literature. For the purpose of the study, it was important to propose a research framework for users’ perceptions on the security of mobile computing with the potential for the adoption of e-applications in South Africa. The research evaluated the proposed framework to establish if there is any relationship between the e-application adoption factors. Furthermore, the hypotheses were tested to determine which factors would influence the adoption of e-applications in South Africa. Technology Adoption Model 2 (TAM2) and Diffusion of Innovation (DOI) provide the theoretical basis for explaining how users perceive e-application services that they access and operate through mobile computing. To achieve that, a quantitative study was conducted with South African residents, with respect to mobile security perceptions; 476 valid questionnaires were received from the participants who were selected non-randomly. Questionnaires were developed from the proposed research framework derived from DOI and TAM2 and the items were adopted from other prior technology adoption studies. Through the use of the survey instrument developed for this study, data were collected in order to address the importance of this study based on the problem statement posed in the first chapter of this dissertation. The valid questionnaires were analysed by using the Statistical Package for the Social Sciences (SPSS), Version 24.0. Reliability analysis, principal component analysis, correlations and multiple linear regression tests were conducted. Among other things this study made sure that ethical considerations are adhered to. The findings revealed positive relationships between perceived usefulness of security mechanisms, perceived ease of use of security mechanisms, subjective norm on security mechanisms, relative advantage of security mechanisms, compatibility of security mechanisms, complexity of security mechanisms, aesthetics of security mechanisms interface and intention to adopt e-applications. Furthermore, subjective norm on security mechanisms was strongly correlated to intention to adopt e-applications, complexity of security mechanisms strongly correlated to perceived usefulness of security mechanisms, relative advantage of security mechanisms and aesthetic of security mechanisms interface strongly correlated to perceived usefulness of security mechanisms. In addition, subjective norm of security mechanisms strongly influence intention to adopt eapplications in South Africa. Also, aesthetics of security mechanisms interface strongly influence both perceived usefulness of security mechanisms and perceived ease of use of security mechanisms. The reason behind it may be interpreted as users nowadays seeing the beauty as the platform to attract and encourage them to use e-applications. Finally, the proposed model analysis and survey evaluation will enable South African organizations to make informed decisions about the use of e-applications services. These findings contribute to a road map for the education sector, government sector, financial institutions, and retail sector as well as to encourage their customers or clients to adopt e-applications.

Context: This protocol is as a supplementary document to our review paper that investigates security-related challenges and solutions that have occurred during the past decade (from January 2003 to December 2014). Objectives: The objective of this systematic review is to identify security-related challenges, security goals, and defenses in ubiquitous computing by answering to three main research questions. First, demographic data and trends will be given by analyzing where, when and by whom the research has been carried out. Second, we will identify security goals that occur in ubiquitous computing, along with attacks, vulnerabilities and threats that have motivated the research. Finally, we will examine the differences in addressing security in ubiquitous computing with those in traditional distributed systems. Method: In order to provide an overview of security-related challenges, goals and solutions proposed in the literature, we will use a systematic literature review (SLR). This protocol describes the steps which are to be taken in order to identify papers relevant to the objective of our review. The first phase of the method includes planning, in which we define the scope of our review by identifying the main research questions, search procedure, as well as inclusion and exclusion criteria. Data extracted from the relevant papers are to be used in the second phase of the method, data synthesis, to answer our research questions. The review will end by reporting on the results. Results and conclusions: The expected results of the review should provide an overview of attacks, vulnerabilities and threats that occur in ubiquitous computing and that have motivated the research in the last decade. Moreover, the review will indicate which security goals are gaining on their significance in the era of ubiquitous computing and provide a categorization of the security-related countermeasures, mechanisms and techniques found in the literature. (authors' abstract)

The Transmission Line Matrix (TLM) method is an existing and established mathematical method for conducting computational electromagnetic (CEM) simulations. TLM models Maxwell s equations by discretising the contiguous nature of an environment and its contents into individual small-scale elements and it is a computationally intensive process. This thesis focusses on parallel processing optimisations to the TLM method when considering the opposing ends of the contemporary computing hardware spectrum, namely large-scale computing systems versus small-scale mobile computing devices. Theoretical aspects covered in this thesis are: The historical development and derivation of the TLM method. A discrete random variable (DRV) for rain-drop diameter,allowing generation of a rain-field with raindrops adhering to a Gaussian size distribution, as a case study for a 3-D TLM implementation. Investigations into parallel computing strategies for accelerating TLM on large and small-scale computing platforms. Implementation aspects covered in this thesis are: A script for modelling rain-fields using free-to-use modelling software. The first known implementation of 2-D TLM on mobile computing devices. A 3-D TLM implementation designed for simulating the effects of rain-fields on extremely high frequency (EHF) band signals. By optimising both TLM solver implementations for their respective platforms, new opportunities present themselves. Rain-field simulations containing individual rain-drop geometry can be simulated, which was previously impractical due to the lengthy computation times required. Also, computationally time-intensive methods such as TLM were previously impractical on mobile computing devices. Contemporary hardware features on these devices now provide the opportunity for CEM simulations at speeds that are acceptable to end users, as well as providing a new avenue for educating relevant user cohorts via dynamic presentations of EM phenomena.

Le développement d'applications sur réseaux mobiles ad hoc présente des contraintes liées à la mobilité des terminaux, à la nature décentralisée des manets, et aux ressources limitées, et nécessite donc la mise en place d'une algorithmique nouvelle. Cette thèse propose des algorithmes permettant la mise en place d'un système de partage de données sur manet : - un algorithme de création de grappes de terminaux mobiles stables dans le temps, qui présente l'avantage de ne pas utiliser de ressources réseaux (utilisation informations inter-couches). - un algorithme de réplication de données pro-actif, qui maintien un nombre de répliques k proportionnel au nombre de terminaux présents et les place sur les terminaux les plus susceptibles de les utiliser. Cela augmente la disponibilité et la fiabilité du service. - un algorithme de gestion de cache, qui maintient le nombre de répliques au minimum permettant un usage efficace du réseau et offrant une bonne disponibilité. D'une part, il élimine les données utilisées le moins récemment et dont le nombre de répliques est supérieur à k. D'autre part, il diminue la charge réseau en éliminant les répliques de données non utilisées par leur hôte.

La gestion des perturbations des flux de production (problèmes d'approvisionnement, défaillances des ressources, problèmes de qualité...) est une problèmatique importante lors du pilotage de systèmes de production. Les architectures de pilotage existantes offrent peu de concepts à la fois spécifiquement dédiés et suffisament génériques pour permettre de gérer une variété de types de perturbations. Dans ce contexte, l'immunité biologique représente un système naturellement capable de réagir et de s'adapter aux menaces qui guettent l'organisme hôte. Nous nous inspirons des principes de fonctionnement de ce système pour identifier les principales caractéritiques d'une architecture distribuée de pilotage. Cette architecture met en oeuvre des fonctions suffisamment génériques et spécifiquement dédiées à la gestion des perturbations, telles que les fonctions de détection, d'identification et de réaction aux perturbations. Cette architecture est réalisée grâce à la technologie des systèmes multi-agents, et permet en plus de capitaliser les connaissances sur les perturbations en vue d'une réalisation future

Our increasing reliance on mobile devices has given rise to a new class of software applications (i.e., mobile apps). Tens of thousands of developers have developed hundreds of thousands of mobile apps that are available across multiple platforms. These apps are used by millions of people around the world every day. However, most software engineering research has been performed on large desktop or server applications. We believe that research efforts must begin to examine mobile apps. Mobile apps are rapidly growing, yet they differ from traditionally-studied desktop/server applications. In this thesis, we examine such apps by performing three quantitative studies. First, we study differences in the size of the code bases and development teams of desktop/server applications and mobile apps. We then study differences in the code, dependency and churn properties of mobile apps from two different mobile platforms. Finally, we study the impact of size, coupling, cohesion and code reuse on the quality of mobile apps. Some of the most notable findings are that mobile apps are much smaller than traditionally-studied desktop/server applications and that most mobile apps tend to be developed by only one or two developers. Mobile app developers tend to rely heavily on functionality provided by the underlying mobile platform through platform-specific APIs. We find that Android app developers tend to rely on the Android platform more than BlackBerry app developers rely on the BlackBerry platform. We also find that defects in Android apps tend to be concentrated in a small number of files and that files that depend on the Android platform tend to have more defects. Our results indicate that major differences exist between mobile apps and traditionally-studied desktop/server applications. However, the mobile apps of two different mobile platforms also differ. Further, our results suggest that mobile app developers should avoid excessive platform dependencies and focus their testing efforts on source code files that rely heavily on the underlying mobile platform. Given the widespread use of mobile apps and the lack of research surrounding these apps, we believe that our results will have significant impact on software engineering research. / Thesis (Master, Computing) -- Queen's University, 2013-01-24 10:15:56.086

In this thesis we look into usability in the context of smartphone applications. We selected three research areas to investigate, namely Wireless Personal Area Networks, Context-awareness, and Remote Information Access. These areas are investigated through a series of experiments, which focuses on important aspects of usability within software applications. Additionally, we mainly use smartphone devices in the experiments. In experiment 1, Multi-Platform Bluetooth Remote Control, we investigated Wireless Personal Area Networks. Specifically, we implemented a system consisting of two clients, which were created for Java ME and Windows Mobile, and integrated with a server application installed on a Bluetooth-enabled laptop. For experiments 2 and 3, Context-aware Meeting Room and PainDroid: an Android Application for Pain Management, we looked closely at the research area of Contextawareness. The Context-aware Meeting Room was created to automatically send meeting participants useful meeting notes during presentations. In experiment 3, we investigated the use of on-device sensors for the Android platform, providing an additional input mechanism for a pain management application, where the accelerometer and magnetometer were used. Finally, the last research area we investigated was Remote Information Access, where we conducted experiment 4, Customised Android Home Screen. We created a system that integrated both a cloud-based server application and a mobile client running on the Android platform. We used the cloud-computing platform to provide context management features, such as the ability to store the user configuration that was automatically pushed to the mobile devices.