The Bluetooth Scatternet Formation (BSF) problem can be defined as the problem of forming wireless networks of Bluetooth devices in an efficient manner. A number of restrictions imposed by the Bluetooth specifications make the BSF problem challenging and unique. Many interesting solution algorithms have been proposed in the literature to solve this problem. In this thesis, we investigate the BSF problem. We concentrate on problems introduced by the procedures of device discovery of the Bluetooth specifications and on the different solutions used by BSF algorithms to deal with these problems. We study also in this thesis problems introduced by the specifications of link establishment in Bluetooth due to their close interaction with the device discovery specifications. We survey and categorize the different device discovery techniques used by BSF algorithms. This categorization is then used as a basis to identify the different theoretical computational models used to study BSF algorithms. We argue, in this thesis, that the currently available models for Bluetooth wireless networks do not model adequately, in most cases, the complexities of the Bluetooth specifications and we show that these models were oversimplified in many cases. A general computational model will be useful as a starting point to design BSF algorithms and to compare the different and numerous BSF algorithms – especially in term of the execution time efficiency. In this thesis, we provide a set of suggestions that will help in the creation of such model. We survey a number of studies that examined in more depth the specifications of device discovery in Bluetooth. We survey also other studies that attempted to simplify the Bluetooth network model, either by suggesting modifications on the Bluetooth specifications or by the use of communication technologies other than Bluetooth. Finally, we present some experiments accompanied with analyzes to show the complexities of the Bluetooth specifications and their sensitivity to minor changes (whether in the specifications or in their implementation).

Intelligent Transport System (ITS) has become a hot research topic over the past decades. ITS is a system that applies the following technologies to the whole transportation management system efficiently, including information technique, wireless communication, sensor networks, control technique, and computer engineering. ITS provides an accurate, real time and synthetically efficient transportation management system. Obviously, Vehicular Ad Hoc NETworks (VANETs) attract growing attention from both the research community and industry all over the world. This is because a large amount of applications are enabled by VANETs, such as safety related applications, traffic management, commercial applications and general applications. When connecting to the internet or communicating with different networks in order to access a variety of services using VANETs, drivers and passengers in different cars need to be able to exchange messages with gateways from their vehicles. A secure gateway discovery process is therefore critical, because vehicles should not be subject to security attacks while they are communicating; however, currently there is no existing protocol focusing on secure gateway discovery. In this thesis, we first analyze and compare current existing secure service discovery protocols and then we propose a Secure Gateway Localization and Communication System for Vehicular Ad Hoc Networks (SEGAL), which concentrates on the security issue in gateway discovery. We focus on the authentication aspect by proposing secure cluster based VANETs, that can ensure the gateway discovery messages exchanged through secure clusters. We present the principle and specific process of our SEGAL protocol and analyze its performance to guarantee its outstanding practical applicability.

In 2005 and 2010, high sea surface temperatures caused widespread coral bleaching on Jamaica’s north coast reefs. Three shallow (9m) reef sites were surveyed during each event to quantify the prevalence and intensity of coral bleaching. In October 2005, 29-57% of the colonies surveyed were bleached. By April 2006, 10% of the corals remained pale/partially bleached. Similarly, in October 2010, 23-51% of corals surveyed at the same sites were bleached. By April 2011, 12% of the colonies remained pale/partially bleached. Follow-up surveys revealed low coral mortality following both events, with an overall mean of 4% partial colony mortality across all species and sites observed in April 2006, and 2% in April 2011. Mixed effects models were used to quantify the relationship between colony size and (a) bleaching intensity, and (b) bleaching related mortality among coral species. The bleaching intensity model explained 51% of the variance in the bleaching response observed during the two events. Of this 51%, fixed effects accounted for ~26% of the variance, 17% of which was attributed to species-specific susceptibility to bleaching , 5% to colony size, <1% colony morphology and 4% to the difference in bleaching intensity between the two events. The random factor (site) accounted for the remaining ~25% of the variance. The mortality model explained 16% of the variance in post bleaching mortality with fixed effects, including colony size, morphology and species explaining ~11% of the variance, and the random effect (site) explaining 5%. On average, there was a twofold difference in bleaching intensity between the smallest and the largest size classes. Modelling the relationship between colony level characteristics and site-specific environmental factors on coral species’ susceptibility to thermal stress can shed light on community level responses to future disturbances.

Handheld devices are becoming increasingly common, and they have varied range of resources. Mobile Cloud Computing (MCC) allows resource constrained devices to offload computation and use storage capacities of more resourceful surrogate machines. This enables creation of new and interesting applications for all devices. We propose a scheme that constructs a high-performance de-centralized system by a group of volunteer mobile devices which come together to form a resourceful unit (cloudlet). The idea is to design a model to operate as a public-resource between mobile devices in close geographical proximity. This cloudlet can provide larger storage capability and can be used as a computational resource by other devices in the network. The system needs to watch the movement of the participating nodes and restructure the topology if some nodes that are providing support to the cloudlet fail or move out of the network. In this work, we discuss the need of the system, our goals and design issues in building a scalable and reconfigurable system. We achieve this by leveraging the concept of virtual dominating set to create an overlay in the broads of the network and distribute the responsibilities in hosting a cloudlet server. We propose an architecture for such a system and develop algorithms that are requited for its operation. We map the resources available in the network by first scoring each device individually, and then gathering these scores to determine suitable candidate cloudlet nodes. We have simulated cloudlet functionalities for several scenarios and show that our approach is viable alternative for many applications such as sharing GPS, crowd sourcing, natural language processing, etc.

Existing methods used for service discovery assume that the world is static, con- sidering a predetermined set of attributes. As a result, current discovery techniques return many results that are irrelevant. Our approach to high quality service dis- covery improves the results’ relevancy by considering dynamic attributes with values changing over time. Using this approach, we reveal structure from the data to satisfy the consumers’ experiences. Web service quality is a set of dynamic attributes used to rank services with similar functionalities. When picking a service to execute financial transactions effi- ciently, we might consider availability, reliability, response time, and transaction cost as quality indicators. Supporting dynamic attributes is a feature critical to providing exceptional quality service discovery. In addition, effective service discovery requires detailed context models that describe both static and dynamic features. The context takes into consideration the situation of the service, the operating environment, the users’ circumstances, and their preferences. For instance, latency is an important issue in stock trading services with direct impact on revenue. One of the main challenges in enabling dynamic service discovery is developing techniques and models to handle the novel aspects of the web service paradigm. This challenge leads to a variety of research questions related to measuring, monitoring, or querying of dynamic attributes, while guaranteeing integrity and validity. We outline an architecture framework called Static Discovery Dynamic Selection (SDDS) to gather and manage dynamic attributes considering both context and do- main information at discovery time—augmenting static mechanisms. The architec- ture of SDDS defines individual components that collectively satisfy flexible and ac- curate service selection with a robust resource management approach capable of con- sidering high-frequency data. Moreover, we devised a multi-criteria decision making algorithm that considers the knowledge domain and the user context, and accordingly, the algorithm returns a small set of accurate and reliable results. As part of the SDDS framework, autonomic computing adds self-adaptability by taking highly dynamic context information into account. The impact of our method is demonstrated in an implementation of the model. We demonstrate that increasing the adaptability of the web service discovery by including context information provides a noticeable reduction in the number of results returned compared to static web service discovery methods. We extend the proposed infrastructure to ascertain whether a particular service satisfies, at execution time, specific security properties. We introduce the notion of certified web service assurance, characterizing how consumers of the service can specify the set of security properties that a service should satisfy. In addition, we illustrate a mechanism to re-check security properties when the execution context changes. To this end, we introduce the concept of a context-aware certificate and describe a dynamic, context-aware service discovery environment. / Graduate

The dairy industry has undergone a dynamic phase during the past two decades. Innovations in terms of technologies, processes, and products have changed the way the production of milk is done. This research takes an exploratory approach to look at the process of opportunity discovery within farm businesses and what firms in the dairy industry are doing to become more innovative. In addition, this research looks at the strategies farmers are using to successfully implement those innovations. An important factor that could affect the performance of a firm is the degree of which the firm is able to become aware of and exploit innovations that help bridge productivity and opportunity gaps. Data is collected through qualitative tools, including in-depth interviews of dairy producers from Saskatchewan, Canada and Aguascalientes, Mexico. Such data collection provides this research with specific insights into the process of opportunity discovery. It also indicates which managerial practices moderate the successful discovery and exploitation of business opportunities in the dairy industry. A theoretical framework was developed around four managerial factors; networking, human capital, market orientation and entrepreneurial orientation. Several propositions were built to identify the impact of these factors on the discovery and exploitation of opportunities in the dairy industry in both Canada and Mexico. This research shed more light on why some producers are more productive than others and how this is allowing some dairy producers to be more profitable. In addition, findings compare both industries and the differences and similarities are shown in terms of operations, managerial styles and processes in which the discovery and exploitation of opportunities take place.

Dopamine D3 receptors (DRD3) are implicated in relapse to drugs. The current study investigated the role of DRD3 in cue-induced reinstatement of nicotine-seeking in rats. Rats were trained to lever-press for intravenous infusions of nicotine, associated with the illumination of a cue-light, under a fixed-ratio schedule of reinforcement. Following extinction of the behaviour, where lever pressing had no consequences, reinstatement testing was performed by reintroduction of the cues after systemic or local administration (into discrete brain areas) of the DRD3 selective antagonist SB277011-A. Systemic antagonism of DRD3 significantly attenuated cue-induced reinstatement of nicotine-seeking. The same effect was observed upon infusions of SB277011-A into the basolateral amygdala or the lateral habenula, but not the nucleus accumbens. The current findings implicate DRD3 in cue-induced reinstatement of nicotine, delineate some of the neural substrates underlying this role and support a potential for using selective DRD3 antagonists for the prevention of relapse to smoking.

Dopamine D3 receptors (DRD3) are implicated in relapse to drugs. The current study investigated the role of DRD3 in cue-induced reinstatement of nicotine-seeking in rats. Rats were trained to lever-press for intravenous infusions of nicotine, associated with the illumination of a cue-light, under a fixed-ratio schedule of reinforcement. Following extinction of the behaviour, where lever pressing had no consequences, reinstatement testing was performed by reintroduction of the cues after systemic or local administration (into discrete brain areas) of the DRD3 selective antagonist SB277011-A. Systemic antagonism of DRD3 significantly attenuated cue-induced reinstatement of nicotine-seeking. The same effect was observed upon infusions of SB277011-A into the basolateral amygdala or the lateral habenula, but not the nucleus accumbens. The current findings implicate DRD3 in cue-induced reinstatement of nicotine, delineate some of the neural substrates underlying this role and support a potential for using selective DRD3 antagonists for the prevention of relapse to smoking.

Discovering novel compounds that stimulate or abrogate angiogenesis can lead to development of new therapeutic agents that may effectively treat diseases with pathological angiogenesis. The zebrafish model allows for a whole-organism approach to drug discovery. Advantages over other animal models include small embryo size, fecundity, rapid embryonic development, optical clarity and easy accessibility of the embryos. My goal is to validate the therapeutic efficacy and identify the molecular mechanisms of action of three compounds identified from our previous chemical genetic screens. Fenretinide promoted angiogenesis in zebrafish embryos but inhibited the angiogenesis-dependent process of fin regeneration. The pro-angiogenic effects of fenretinide appear secondary to the stimulation of somitogenesis. I3M potently inhibited angiogenesis and fin regeneration, and may act partially through the notch pathway. Lastly, I validated the anti-angiogenic effect of a novel compound DHM. Comprehensively, my studies support the utility of zebrafish as a versatile tool for anti-angiogenic drug discovery.

Discovering novel compounds that stimulate or abrogate angiogenesis can lead to development of new therapeutic agents that may effectively treat diseases with pathological angiogenesis. The zebrafish model allows for a whole-organism approach to drug discovery. Advantages over other animal models include small embryo size, fecundity, rapid embryonic development, optical clarity and easy accessibility of the embryos. My goal is to validate the therapeutic efficacy and identify the molecular mechanisms of action of three compounds identified from our previous chemical genetic screens. Fenretinide promoted angiogenesis in zebrafish embryos but inhibited the angiogenesis-dependent process of fin regeneration. The pro-angiogenic effects of fenretinide appear secondary to the stimulation of somitogenesis. I3M potently inhibited angiogenesis and fin regeneration, and may act partially through the notch pathway. Lastly, I validated the anti-angiogenic effect of a novel compound DHM. Comprehensively, my studies support the utility of zebrafish as a versatile tool for anti-angiogenic drug discovery.