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Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 186-192).

Natural communities of species embody complex interrelationships between the structure of the interspecific interaction network, dynamics of species' populations, and the stability of the system as a whole. Studying these interrelationships is crucial for understanding the survival of species in nature. In this context, studying the food web (the network of who-eats-whom) embedded in each interaction network is particularly important because trophic interactions are the main channels of energy flow in all ecosystems. Using a combination of mathematical modeling and empirical data analyses, this study explores the interrelationship between food web structure and multi-species coexistence in local communities. Chapter 1 of this thesis places the overall dissertation study in context of the history of research on species interaction networks and food webs. In Chapter 2, I use a population dynamical model to show how the requirements of stable multi-species coexistence results in the emergence of specific, nonrandom configurations of food web structure during community assembly. These structural "signatures" can be used to empirically gauge the importance of interaction-driven dynamical stability constraints in natural communities. In Chapter 3, I extend the model analyzed in Chapter 2 by imposing biologically feasible constraints on its parameters. This is made possible by the allometric scaling between individual metabolism and body size, and the constraints on interspecific trophic interactions due to body size differences between pairs of interacting species. I show that, using this approach, it is possible to interlink three aspects of local communities that have typically been studied in isolation: the species' body mass distribution, the distribution of ratios of body sizes of consumer and resource species (e.g., predator and prey), and certain food web structural features. Some of these features have previously lacked explanatory models. Finally in Chapter 4, using empirical data from nine communities across a range of habitats, I test some theoretical predictions of the previous chapter. The results provide strong evidence that the food web structure of natural communities do indeed exhibit signatures of dynamical stability constraints, and that the model developed in Chapters 2 and 3 is successfully able to predict a number of empirically observed food web structural features. / text

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Thesis (Ph. D.)--University of Texas at Austin, 2009. / Title from PDF title page (University of Texas Digital Repository, viewed on Sept. 17, 2009). Vita. Includes bibliographical references.

Le travail développe un modèle de portfolio à propos de la dollarisation financière (FD), et l'estime pour la Russie. La contribution de ce travail sera de construire le premier modèle théorique de variance moyenne asymétrique d'aplatissement sur la dollarisation financière et de le valider empiriquement. Le travail se fonde sur des recherches antérieures qui ont trouvé que l'ajout de moments plus élevés, comme l'asymétrie et l'aplatissement, à la variance minimale du portfolio(MVP) permettant une meilleure modélisation des choix de portfolio et de développe un model comme celui-ci pour la FD. Nous utilisons ensuite les méthodes Markovswitching sur les données mensuelles pour les dépôts bancaires en Russie depuis la fin des années 1990 afin de documenter l'influence dominante de l'inflation et de la dépréciation de la monnaie et de leurs moments comme principaux déterminants de dépôt de dollarisation dans un cadre de variance-moyenne-asymétrique-aplatie en période de crise, par opposition aux périodes normales. / This thesis develops a portfolio model of financial dollarization (FD) and estimates it for Russia. The contribution of this work will be to construct the first theoretical meanvariance-skewness-kurtosis model of financial dollarization and to validate it empirically. The work builds on previous research which found that adding higher moments, as Skewness and Kurtosis, to the minimum variance portfolio (MVP) enables a better modelling of portfolio choice, and develops such a model for FD. We then use Markovswitching methods on monthly data for bank deposits in Russia since the late 1990s to document the dominant influence of inflation and currency depreciation and their moments as the main determinants of deposit dollarization in a mean-varianceskewness-kurtosis framework during crisis as opposed to normal periods.

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Long-range dependence in discrete and continuous time Markov chains over a countable state space is defined via embedded renewal processes brought about by visits to a fixed state. In the discrete time chain, solidarity properties are obtained and long-range dependence of functionals are examined. On the other hand, the study of LRD of continuous time chains is defined via the number of visits in a given time interval. Long-range dependence of Markov chains over a non-countable state space is also carried out through positive Harris chains. Embedded renewal processes in these chains exist via visits to sets of states called proper atoms. Examples of these chains are presented, with particular attention given to long-range dependent Markov chains in single-server queues, namely, the waiting times of GI/G/1 queues and queue lengths at departure epochs in M/G/1 queues. The presence of long-range dependence in these processes is dependent on the moment index of the lifetime distribution of the service times. The Hurst indexes are obtained under certain conditions on the distribution function of the service times and the structure of the correlations. These processes of waiting times and queue sizes are also examined in a range of M/P/2 queues via simulation (here, P denotes a Pareto distribution).

ABSTRACT After Taiwan Air Cargo Terminal ¡]TACT¡^has walked through the monopoly, deregulation, privatization process, the services which they have been providing can't match the demand of modern cargo transportation, including of high-service-quality and high-speed-pass customs. The basic theory we adopted is¡§ Value Marketing Chains¡¨¡]Porter, 1985¡^and ¡§Competitive Advantages¡¨¡]Porter, 1990¡^in this study, its goals as follows: 1. To investigate the important service value factors of air cargo warehouse and difference range of service value after the privatization, 2. Discuss the correlation between service value and competitive advantages, 3. Use TACT cases to explain have an empirical on value chains and competitive advantages. This study is designed with retrospective-prospective due. By citing secondary data and in depth interviews offered from hardware etc. four key successful factors, by identifying, value delivery six step, and three stages cargo terminal organization type change, analyzed includes its value and four competitive advantages, example first-mover advantages etc. Furthermore, to design questionnaires and send 200 pieces surveying, get through depth interviews and data analysis, it show the four services value after privatization is high-degree and statistical significance expect hard-service . This study to codify a few consequence, example extend information service, quickly construct step, promote fixable service, aggrandize alliance, adjust contract and law, etc. keywords¡GPrivatization , Value chains , Value marketing chains , Competitive advantages..