The primary aim of this thesis is to advance economics' understanding of the organization of political parties, for the purpose of explaining the policy choices that result from collective decision procedures. Motivating this inquiry is the benign neglect that the political party as an organization has long suffered from in economics, in a manner that mirrors depictions of the firm in early neoclassical analysis. Accordingly, this thesis first considers the question of the relative influence of different contributors to the political parties' electoral activities, i.e. special-interest groups contributing money and individual party activists volunteering their time, on their choice of policy platforms. It is found that the presence of activists induces parties to offer differentiated policy platforms, even in the presence of a special-interest group whose contributions are perfectly substitutable with those of activists. Concurrently, the special interest's influence is to bias the parties' platforms towards its preferred policy. Second, the internal dynamics of parties organized into factions sharing common goals are investigated. It is studied how they affect the party leader's choice of policies while in office and her accountability to voters, through the threat of her removal from the party's helm. While occasionally acting as a distortion on the election mechanism's effectiveness for keeping politicians accountable, the presence of the politician's party is accountability-enhancing especially in the presence of other distortions. This contributes to a second-best theory of politics. This thesis' secondary aim is to contribute to restoring the use of moral and ethical concerns in normative analysis and political economy. This is warranted by the fact that moral and ethical motives matter more in such contexts than in most market transactions, where rational self-interested behaviour largely prevails. This objective is primarily represented in this thesis' study of normative analysis as conditioned on a societal consensus. This study asks how redistributive policies are to be optimally-chosen when the extent of societal co-operation regarding work participation depends on a social norm. Its main finding is that constraining the social planner's choices on the extent of societal cohesion restricts the scope of redistribution compared with an unconstrained social planner. / Thesis (Ph.D, Economics) -- Queen's University, 2011-11-03 12:16:33.632

With the advancement of communication technology, more and more control processes happen in networked environment. This makes it possible for us to deploy multiple systems in a spatially distributed way such that they could finish certain tasks collaboratively. While it brings about numerous advantages over conventional control, challenges arise in the mean time due to the imperfection of communication. This thesis is aimed to solve some problems in cooperative control involving multiple agents in the presence of communication constraints. Overall, it is comprised of two main parts: Distributed consensus in multi-agent systems and bilateral teleoperation. Chapter 2 to Chapter 4 deal with the consensus problem in multi-agent systems. Our goal is to design appropriate control protocols such that the states of a group of agents will converge to a common value eventually. The robustness of multi-agent systems against various adverse factors in communication is our central concern. Chapter 5 copes with bilateral teleoperation with time delays. The task is to design control laws such that synchronization is reached between the master plant and slave plant. Meanwhile, transparency should be maintained within an acceptable level. Chapter 2 investigates the consensus problem in a multi-agent system with directed communication topology. The time delays are modeled as a Markov chain, thus more characteristics of delays are taken into account. A delay-dependent approach has been proposed to design the Laplacian matrix such that the system is robust against stochastic delays. The consensus problem is converted into stabilization of its equivalent error dynamics, and the mean square stability is employed to characterize its convergence property. One feature of Chapter 2 is redesign of the adjacency matrix, which makes it possible to adjust communication weights dynamically. In Chapter 3, average consensus in single-integrator agents with time-varying delays and random data losses is studied. The interaction topology is assumed to be undirected. The communication constraints lie in two aspects: 1) time-varying delays that are non-uniform and bounded; 2) data losses governed by Bernoulli processes with non-uniform probabilities. By considering the upper bounds of delays and probabilities of packet dropouts, sufficient conditions are developed to guarantee that the multi-agent system will achieve consensus. Chapter 4 is concerned with the consensus problem with double-integrator dynamics and non-uniform sampling. The communication topology is assumed to be fixed and directed. With the adoption of time-varying control gains and the theory on stochastic matrices, we prove that when the graph has a directed spanning tree and the control gains are properly selected, consensus will be reached. Chapter 5 deals with bilateral teleoperation with probabilistic time delays. The delays are from a finite set and each element in the set has a probability of occurrence. After defining the tracking error between the master and slave, the input-to-state stability is used to characterize the system performance. By taking into account the probabilistic information in time delays and using the pole placement technique, the teleoperation system has achieved better position tracking and enhanced transparency. / Graduate

Consensus is a central issue in designing multi-agent systems (MASs). How to design control protocols under certain communication topologies is the key for solving consensus problems. This thesis is focusing on investigating the consensus protocols under different scenarios: (1) The second-order system dynamics with Markov time delays; (2) The Euler-Lagrange dynamics with uniform and nonuniform sampling strategies and the event-based control strategy. Chapter 2 is focused on the consensus problem of the multi-agent systems with random delays governed by a Markov chain. For second-order dynamics under the sampled-data setting, we first convert the consensus problem to the stability analysis of the equivalent error system dynamics. By designing a suitable Lyapunov function and deriving a set of linear matrix inequalities (LMIs), we analyze the mean square stability of the error system dynamics with fixed communication topology. Since the transition probabilities in a Markov chain are sometimes partially unknown, we propose a method of estimating the delay for the next sampling time instant. We explicitly give a lower bound of the probability for the delay estimation which can ensure the stability of the error system dynamics. Finally, by applying an augmentation technique, we convert the error system dynamics to a delay-free stochastic system. A sufficient condition is established to guarantee the consensus of the networked multi-agent systems with switching topologies. Simulation studies for a fleet of unmanned vehicles verify the theoretical results. In Chapter 3, we propose the consensus control protocols involving both position and velocity information of the MASs with the linearized Euler-Lagrange dynamics, under uniform sampling and nonuniform sampling schemes, respectively. Then we extend the results to the case of applying the centralized event-triggered strategy, and accordingly analyze the consensus property. Simulation examples and comparisons verify the effectiveness of the proposed methods. / Graduate / 0548

This three-stage study led to the development of a delineation model of occupational therapy practice for children with Attention Deficit Hyperactivity Disorder (ADHD). Stage one explored the current practice of occupational therapy in the United Kingdom (UK) by conducting a national survey of 282 paediatric occupational therapists. Results indicated that there were only a small number of occupational therapists (8.5%) working in a designated service for children with ADBD. This result suggested that occupational therapy for children with ADHD is a small field of practice. Stage two involved the consensus development on the role of occupational therapy for children with ADHD. Seventy-two paediatric occupational therapists participated in the study. The therapists' top six priorities of assessment and five priorities of intervention were identified. An occupational therapy delineation model of practice was developed by integrating data generated from this research, information from the literature review, and the author's clinical experience. In order to apply the model to clinical practice, a family-centred occupational therapy care package was developed. The third stage evaluated the process and outcome of the devised care package by conducting a multi-centred efficacy study. Twenty occupational therapists from the four countries in the UK attended a 3-day course to learn to implement the care package. Following their training, they submitted data on a sample of 20 children with ADHD. The majority of these children (85%) showed improvement in their behavioural patterns after the implementation of the care package. Over half of the cases (65%) had statistically significant changes of scores in the ADHD Rating Scales. Parents also reported experiencing good family-centred care delivered by the research therapists. The whole study makes a significant contribution to occupational therapy knowledge by creating a new delineation model of practice for which the research undertaken offers some validation.

During the last 15 years, the former “star pupil” of the Washington Consensus, Argentina, has witnessed a dramatic turn of international economic regime. Having pursued a markedly neoliberal economic agenda previous to the 2001 financial crisis, external and internal factors now suggest a structural shift in Argentine politics. Using regime theory and theoretical concepts by international relations theorist Evelyn Goh, this study investigates the implications of a changing US hegemony on Argentine compliance with the leading international economic regime of the unipolar world order.

In this thesis, we consider the problem of diffusing information resiliently in networks that contain misbehaving nodes. Previous strategies to achieve resilient information diffusion typically require the normal nodes to hold some global information, such as the topology of the network and the identities of non-neighboring nodes. However, these assumptions are not suitable for large-scale networks and this necessitates our study of resilient algorithms based on only local information. We propose a consensus algorithm where, at each time-step, each normal node removes the extreme values in its neighborhood and updates its value as a weighted average of its own value and the remaining values. We show that traditional topological metrics (such as connectivity of the network) fail to capture such dynamics. Thus, we introduce a topological property termed as network robustness and show that this concept, together with its variants, is the key property to characterize the behavior of a class of resilient algorithms that use purely local information. We then investigate the robustness properties of complex networks. Specifically, we consider common random graph models for complex networks, including the preferential attachment model, the Erdos-Renyi model, and the geometric random graph model, and compare the metrics of connectivity and robustness in these models. While connectivity and robustness are greatly different in general (i.e., there exist graphs which are highly connected but with poor robustness), we show that the notions of robustness and connectivity are equivalent in the preferential attachment model, cannot be very different in the geometric random graph model, and share the same threshold functions in the Erdos-Renyi model, which gives us more insight about the structure of complex networks. Finally, we provide a construction method for robust graphs.

No description available.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 106-110). Also available via the Internet.

Thesis (M.A. Ed.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 72-73). Also available via the Internet.

Thesis (Ph.D. (Environment and Resource Studies))--Mahidol University, 2009.