Wireless sensor networks have applications in many places from wildlife environments to urban areas. Implementation of such a network is a challenging task because each specific application may require different constraints and objectives. To better meet the application requirements, cognitive wireless sensor network has been recently introduced. However, almost all the previous work in this area has been in theory or by simulation. Hence there is a demand to provide implementable ideas of cognition, implement, and analyze the results. The goal of this thesis is to implement a cognitive wireless sensor network with application in environment monitoring which is aware of the surrounding environment, updates its information based on the dynamic changes in the network status, makes appropriate decisions based on the gained awareness, and forwards required actions to involving nodes. An implementable cognitive idea is proposed based on the characteristics and goals of a cognitive system. Since transmission is one of the most power consuming processes in sensor nodes and non-efficient transmissions of data can lead to a shorter lifetime, this work tries to schedule nodes' transmission rate by the means of cognition and benefits from efficient scheduling of the redundant nodes to improve lifetime. To enhance a wireless sensor network with cognition, new nodes should be added to the architecture called cognitive nodes. Cognitive nodes will take care of most of the tasks in the cognition process while still there is a need to add a level of cognition to each individual node. The main contribution of this work is that it provides an implementable approach to cognition in wireless sensor networks, proposes a low complexity and low cost implementable idea for cognition, addresses implementation issues, and provides experimental results of different setups of the cognitive wireless sensor network. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2011-09-27 00:38:12.455

Communication protocol testing can be done with a test architecture consisting of remote Tester and local Responder processes. By ignoring interaction primitive parameters and additional state variables, it is possible to adapt test sequence generation techniques for finite state machines (FSM) to generate sequences for protocols specified as incomplete finite state machines. / For real protocols, tests can be designed based on the formal specification of the protocol which uses an extended FSM model in specifying the transition types. The transition types are transformed into a simpler form called normal form transitions which can be modelled by a control and a data flow graph. Furthermore, the data flow graph is partitioned to obtain disjoint blocks representing the different functions of the protocol. Tests are designed by considering parameter variations of the input primitives of each data flow function and determining the expected outputs. This methodology gives complete test coverage of all data flow functions and tests for unspecified cases can be designed using the control and data flow graphs. The methodology is applied to two real protocols: Transport protocols Classes 0 and 2.

Despite the importance of inter-cellular (between cell) communication networks in regulating homeostasis in multicellular organisms, very little is known about their topology, dynamics, or functional significance. Inter-cellular communication networks are particularly relevant in stem cell biology, as stem cell fate decisions (self-renewal, proliferation, lineage specification) are tightly regulated based on physiological demand. Using human blood stem cell cultures as an experimental paradigm, we present an integrated experimental and computational approach to interrogate a hierarchically organized tissue network. We have developed a novel mathematical model of blood stem cell development incorporating cell-level kinetic parameters as functions of secreted molecule-mediated inter-cellular networks. By relation to quantitative cellular assays, our model is capable of predictively simulating many disparate features of both normal and malignant hematopoiesis, relating internal parameters and microenvironmental variables to measurable cell fate outcomes. Through integrated in silico and experimental analyses we show blood stem and progenitor cell fate is regulated by cell-cell feedback, and can be controlled non-cell autonomously by dynamically perturbing inter-cellular signalling. Furthermore, we have compiled genome-scale molecular profiles (transcriptome and secretome), publicly available databases, and literature mining to reconstruct soluble factor-mediated inter-cellular signalling networks regulating cell fate decisions. We find that dynamic interactions between positive and negative regulators, in the context of tuneable cell culture parameters, tip the balance between stem cell supportive vs. non-supportive conditions. The cell-cytokine interactions can be summarized as an antagonistic positive-negative feedback circuit wherein stem cell self-renewal is regulated by a balance of megakaryocyte-derived stimulatory factors vs. monocyte-derived inhibitory factors. To understand how the experimentally identified positive and negative regulatory signals are integrated at the intra-cellular level, we define a literature-derived blood stem cell self-renewal network wherein these extracellular signals converge for coherent processing into cell fate decisions. In summary, this work demonstrates the utility of integrating experimental and computational methods to explore complex cellular systems, and represents the first attempt to comprehensively elucidate non-autonomous signals balancing stem cell homeostasis and regeneration.

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In the late 1990s, the internet was heralded as a global opportunity for new ventures. One aspect of this opportunity was the innovation of including small firms and consumers in seamless 'business webs.' The second aspect was the distance insensitivity and internationality of the internet. New ventures appeared in different countries responding to this seemingly global opportunity. In Germany, this response appeared especially strong against the background of years of slow development of the domestic information technology (IT) sector. This thesis examines the role of national government policy in a world being transformed by technology. 'Network thinkers,' following Schumpeter's concept of 'creative destruction,' believed the internet represented a global innovation opportunity. They emphasised the independence and self-governance of globally networked market players, arguing that the territorial basis of national government policy has eroded. The problematique guiding this research effort has emerged from this thinking. Can the concepts associated with network thinking account for the apparently strong entrepreneurial response to the internet in Germany. A detailed study of the development of internet ventures in Germany was carried out to examine this guiding question. The study was supported by quantitative data supplied through a 123-firm survey conducted in the Spring of 1998. This research revealed that the entrepreneurial response in Germany was much weaker than it appeared to contemporary observers. New ventures had to adopt a 'mixed-play' approach which placed them on a less innovative and less international, slower growth trajectory. Two key policy arenas were identified which constrained the development of German internet ventures: (I) The course of telecommunications liberalisation and (2) the initial lack of venture capital. Practitioners have long been aware of the importance of these two determinants for internet development. The main contribution of this thesis has been to add to the understanding of how these two factors have operated in a national environment conditioned by distinctive institutions.