Chan Ho-leung. / "December 2000." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (p. 154-[160]). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

This study was based on the parasite fauna of three anuran systems. In two of the systems; the spadefoot toads, Scaphiopus bombifrons and S. multiplicatus and the fire and yellow-bellied toads, Bombina bombina and B.variegata, inter-species hybridisation occurs. In the third system an autopolyploid species complex involves the Gray treefrogs, Hyla chrysoscelis and H.versicolor. The status of the Scaphiopus hybrid zone in Arizona was re-assessed by cellulose-acetate gel electrophoresis. Genotypic frequencies were comparable to those previously documented, indicating that a region of 'balanced introgression' may exist. Specimens were collected in areas of host sympatry and the distribution of helminths within hosts of different genetic constitution investigated. From extensive surveys of all three systems, parasite frequency distributions were typically aggregated with no evidence of any change in host genetic predisposition to infection. In addition, the surveys have documented a number of new host and/or parasite locality records for each system. Of particular interest was the discovery of the digenean Clinostomum complanatum in a desert environment, an introduction related to human management of the ecosystem. Particular reference was made to the specificity of the polystomatid monogeneans, Polystoma nearcticum infecting members of the H.chrysoscelis- H.versicolor complex and Neodiplorchis scaphiopodis infecting S.bombifrons and S.multiplicatus. For Polystoma, worms from H.chlysoscelis and H.versicolor could not be separated by morphology, which was supported by preliminary crossinfections. This suggests that P.nearcticum infects both members of this complex. For Neodiplorchis, morphological similarity was confirmed by cross-infections which revealed that N.scaphiopodis can reach sexual maturity and produce fully developed larvae in heterospecific hosts. The neotenic development of P. nearcticum and the initial post-oncomiracidial stages of N.scaphiopodis were documented. Furthermore, certain aspects of transmission dynamics were examined by the experimental infection of H. versicolor tadpoles with P. nearcticum.

Chi Him Roger Yip. / Thesis submitted in 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 134-137). / Abstract also in Chinese. / Acknowledgment --- p.1 / Abstract --- p.2 / CONTENTS --- p.3 / Chapter Chapter 1 --- Introduction and Overview --- p.5 / Chapter I. --- Age-earnings profiles --- p.6 / Chapter II. --- An overview of the thesis --- p.24 / Chapter Chapter 2 --- Literature Review --- p.25 / Chapter I. --- Human capital as a determinant of earnings --- p.25 / Chapter A. --- The early roots: Adam Smith --- p.25 / Chapter B. --- Rapid development in human capital theory in the late 20th century --- p.27 / Chapter II. --- Empirical labour economics: Mincer's statistical earnings function --- p.29 / Chapter A. --- Development of the statistical earnings function --- p.29 / Chapter B. --- The problem of ability bias --- p.32 / Chapter III. --- Empirical Evidence --- p.34 / Chapter Chapter 3 --- The Data Sets and the Variables Available --- p.37 / Chapter Chapter 4 --- Earnings Variations among Working Men --- p.40 / Chapter I. --- Summary statistics --- p.40 / Chapter II. --- "Earnings Function, and Estimation Results" --- p.42 / Chapter III. --- Summing-up --- p.52 / Chapter Chapter 5 --- The Contribution of Educational Fields to Earnings --- p.53 / Chapter I. --- Summary statistics --- p.53 / Chapter II. --- Earnings functions with educational fields as dummy variables --- p.63 / Chapter III. --- Summing-up --- p.76 / Chapter Chapter 6 --- Earnings Variations by Industries --- p.78 / Chapter I. --- Summary statistics --- p.78 / Chapter II. --- Earnings functions with industries as dummy variables --- p.83 / Chapter III. --- Contribution of educational fields to earnings --- p.90 / Chapter IV. --- Summing-up --- p.106 / Chapter Chapter 7 --- Earnings Variations by Occupations --- p.107 / Chapter I. --- Summary statistics --- p.107 / Chapter II. --- Earnings functions with occupations as dummy variables --- p.112 / Chapter III. --- Contribution of educational fields to earnings --- p.118 / Chapter IV. --- Summing-up --- p.131 / Chapter Chapter 8 --- Conclusion --- p.132 / Bibliography --- p.134

Idag blir konkurrensen allt hårdare på marknaden, inte minst sagt i modebranschen. Företag tar till alla olika sorters konkurrensstrategier för att just de skall sticka ut från mängden. Här följer en studie inriktat på en av dessa konkurrensstrategier, nämligen marknadskommunikation. Kommunicerar man fel på den hårt konkurerande marknaden idag kan det få förödande effekter. Man måste som sändare av budskapet veta vem mottagaren är. För att nå framgång i modebranschen är det därför viktigt att positionera sig på marknaden så att man differentierar sig från sina konkurrenter. För att differentiera sig måste du hitta ditt eget sätt att kommunicera till ditt segment. Marknadskommunikationens första prioritering är att ge rätt associationer till företagets varumärke, göra företaget attraktivt på marknaden och även att bygga upp och förmedla ett så kallat mervärde. För att få en verklig och realistisk överblick över problemet har vi valt att undersöka hur företaget Wakakuu kommunicerar med sitt segment. Vi har utifrån detta kunnat analysera hur det ser ut i teorin och hur det ser ut i praktiken. Wakakuu är ett företag som har en framgångsrik webbshop och en showroombutik belägen i Hovås, söder om Göteborg. Svenska modebranschens omsättning var 206 miljarder kronor år 2011. 43 % av den totala omsättningen står butikshandeln för och 4 % står e-handeln för. (Svensk handel 2013) Butikshandeln utgör som sagt en stor del av den totala marknaden och detta var en av anledningen till att vi ville samarbeta med en butik. Vi har studerat hur Wakakuu arbetar för att nå ut till deras segment, kvinna 20-30 år, som finns på deras webbshop men ej i deras fysiska butik, för att få detta segment till den fysiska butiken. För att ta reda på detta har vi studerat deras kommunikationskanaler och påverkande faktorer som utgör om en butik blir vald eller ej. Syftet med vår uppsats är att ta reda på hur ett modeföretag kommunicerar med sitt segment. Vi vill undersöka hur kommunikationsprocessen går till. Slutligen kommer vi att analysera vårt resultat och vår teori, vi vill kunna dra paralleller mellan teorin och praktiken. Vi har kommit fram till att Wakakuu har svårigheter med att nå ut till den yngre kundgruppen, kvinna 20-30 år. I de sociala medier som Wakakuu använder för att kommunicera finns den yngre kundgruppen. Dock ser vi ingen positiv effekt utifrån denna kommunikationsprocess. Vi drar här slutsatsen att Wakakuus kommunikation inte når ut ur det informationsbrus som vi lever i, och det uppkommer för många störningar innan kommunikationen når konsumenten att de inte får någon positiv effekt. Vi har också kommit fram till att Wakakuus läge och pris är påverkande faktorer till varför Wakakuu inte väljs utav konsumenten. / Program: Butikschef, textil och mode

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / One of the lessons from the recent global financial crisis is the importance of macro-financial linkage in the economy. Based on this background, this dissertation analyzes the effects of financial frictions on the aggregate activities of the economy, wealth distribution and business cycles. The first chapter investigates the effects of financial development on aggregate capital accumulation and wealth distribution by constructing a heterogeneous-agent general equilibrium model with two idiosyncratic risks, endogenous occupational choice and Holmstrom and Tirole (1999) type financial contracts to prevent moral hazard issue. The benchmark model is calibrated to match the empirical data, where the wealth distribution has a right-hand fat tail and a small number of entrepreneurs hold a large amount of wealth. We find that financial development measured by decrease of monitoring cost contributes to the economy's higher capital accumulation and lower wealth Gini coefficient. The second chapter develops a dynamic stochastic general equilibrium (DSGE) model with financial frictions arising from the moral hazard problem as in Holmstrom and Tirole (1997) together with regulatory capital requirements on the banks. In contrast with the standard BGG (1999) financial accelerator model, we consider the agency problem from hidden action and regulatory capital requirements on the banks in order to examine whether changes of regulatory capital requirements result in credit crunches in the transmissions of aggregate technology and monetary policy shocks. The third chapter explores quantitative experiments using the above DSGE model. We examine whether there exists a "financial accelerator" effect from these kinds of financial frictions and a "credit crunch" from shocks. We find that there exists a "financial accelerator" effect and that financial deepening measured by decrease of financial intermediary's monitoring costs could contribute to mitigating business cycle fluctuations. In particular, no financial frictions with zero monitoring cost could decrease the variance of aggregate investment to around 18.5%. We also find that imposing and increasing capital requirements on the banks could cause decrease of bank's lending ("credit crunch"), thereby amplifying business cycles. / 2031-01-02

Thesis. 1979. Ph.D.--Massachusetts Institute of Technology. Dept. of Urban Studies and Planning. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH. / Vita. / Bibliography: leaves 228-242. / by Rafael Corrada Guerrero. / Ph.D.

Thesis. 1978. M.S.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Anthony H. Wexler. / M.S.

In order to study the real world, scientists (and computer scientists) develop simplified models that attempt to capture the essential features of the observed system. Understanding the power and limitations of these models, when they apply or fail to fully capture the situation at hand, is therefore of uttermost importance. In this thesis, we investigate the role of some of these models in property testing of probability distributions (distribution testing), as well as in related areas. We introduce natural extensions of the standard model (which only allows access to independent draws from the underlying distribution), in order to circumvent some of its limitations or draw new insights about the problems they aim at capturing. Our results are organized in three main directions: (i) We provide systematic approaches to tackle distribution testing questions. Specifically, we provide two general algorithmic frameworks that apply to a wide range of properties, and yield efficient and near-optimal results for many of them. We complement these by introducing two methodologies to prove information-theoretic lower bounds in distribution testing, which enable us to derive hardness results in a clean and unified way. (ii) We introduce and investigate two new models of access to the unknown distributions, which both generalize the standard sampling model in different ways and allow testing algorithms to achieve significantly better efficiency. Our study of the power and limitations of algorithms in these models shows how these could lead to faster algorithms in practical situations, and yields a better understanding of the underlying bottlenecks in the standard sampling setting. (iii) We then leave the field of distribution testing to explore areas adjacent to property testing. We define a new algorithmic primitive of sampling correction, which in some sense lies in between distribution learning and testing and aims to capture settings where data originates from imperfect or noisy sources. Our work sets out to model these situations in a rigorous and abstracted way, in order to enable the development of systematic methods to address these issues.

The field of property testing has been studied for decades, and Boolean functions are among the most classical subjects to study in this area. In this thesis we consider the property testing of Boolean functions: distinguishing whether an unknown Boolean function has some certain property (or equivalently, belongs to a certain class of functions), or is far from having this property. We study this problem under both the standard setting, where the distance between functions is measured with respect to the uniform distribution, as well as the distribution-free setting, where the distance is measured with respect to a fixed but unknown distribution. We obtain both new upper bounds and lower bounds for the query complexity of testing various properties of Boolean functions: - Under the standard model of property testing, we prove a lower bound of \Omega(n^{1/3}) for the query complexity of any adaptive algorithm that tests whether an n-variable Boolean function is monotone, improving the previous best lower bound of \Omega(n^{1/4}) by Belov and Blais in 2015. We also prove a lower bound of \Omega(n^{2/3}) for adaptive algorithms, and a lower bound of \Omega(n) for non-adaptive algorithms with one-sided errors that test unateness, a natural generalization of monotonicity. The latter lower bound matches the previous upper bound proved by Chakrabarty and Seshadhri in 2016, up to poly-logarithmic factors of n. - We also study the distribution-free testing of k-juntas, where a function is a k-junta if it depends on at most k out of its n input variables. The standard property testing of k-juntas under the uniform distribution has been well understood: it has been shown that, for adaptive testing of k-juntas the optimal query complexity is \Theta(k); and for non-adaptive testing of k-juntas it is \Theta(k^{3/2}). Both bounds are tight up to poly-logarithmic factors of k. However, this problem is far from clear under the more general setting of distribution-free testing. Previous results only imply an O(2^k)-query algorithm for distribution-free testing of k-juntas, and besides lower bounds under the uniform distribution setting that naturally extend to this more general setting, no other results were known from the lower bound side. We significantly improve these results with an O(k^2)-query adaptive distribution-free tester for k-juntas, as well as an exponential lower bound of \Omega(2^{k/3}) for the query complexity of non-adaptive distribution-free testers for this problem. These results illustrate the hardness of distribution-free testing and also the significant role of adaptivity under this setting. - In the end we also study distribution-free testing of other basic Boolean functions. Under the distribution-free setting, a lower bound of \Omega(n^{1/5}) was proved for testing of conjunctions, decision lists, and linear threshold functions by Glasner and Servedio in 2009, and an O(n^{1/3})-query algorithm for testing monotone conjunctions was shown by Dolev and Ron in 2011. Building on techniques developed in these two papers, we improve these lower bounds to \Omega(n^{1/3}), and specifically for the class of conjunctions we present an adaptive algorithm with query complexity O(n^{1/3}). Our lower and upper bounds are tight for testing conjunctions, up to poly-logarithmic factors of n.

High-voltage direct-current (HVDC) transmission has higher efficiency and lower expenses for the long-distance bulk-power transmission. A HVDC tap is one type of the multi-terminal HVDC systems which transfers a small amount of power from the HVDC line to the nearby communities with no access to the electricity. Developed from the 1960s, HVDC taps can be summarised into series taps and parallel taps, between which series taps are considered to be more promising on the use of devices and the cost. The conventional series taps have some evident drawbacks, which a modular multilevel based series tap may overcome. Here a novel n-phase Multi-Modular Series HVDC Tap (MMST) is proposed to realise the utilisation of the modular multilevel structure into the series tap and improve the performance of typical series taps. In this PhD thesis the theoretical analysis and the parameter design of two-phase and three-phase MMSTs based on the South-West HVDC Link in Sweden have been carried out. The control strategy for the n-phase MMST, including the load current control, the mean capacitor voltage control and the DC link voltage control, has been designed. In order to verify the feasibility of the proposed topology and the validity of the presented control strategy, simulations have been validated using a low power prototype. The simulation and experimental results indicate that the MMST offers better performance when compared to the conventional series taps.