Normal Approximation in Large Network Models

We develop a methodology for proving central limit theorems in network models with strategic interactions and homophilous agents. Since data often consists of observations on a single large network, we consider an asymptotic framework in which the network size tends to infinity. In the presence of strategic interactions, network moments are generally complex functions of components, where a node's component consists of all alters to which it is directly or indirectly connected. We find that a modification of "exponential stabilization" conditions from the stochastic geometry literature provides a useful formulation of weak dependence for moments of this type. We establish a CLT for a network moments satisfying stabilization and provide a methodology for deriving primitive sufficient conditions for stabilization using results in branching process theory. We apply the methodology to static and dynamic models of network formation

Otaku for Queer Theory and Media Theory

Beautiful Fighting Girl by Saitō Tamaki, translated by J. Keith Vincent and Dawn Lawson. Minneapolis: University of Minnesota Press, 2011. Pp. 213 + xxv. $60.00 cloth, 19.95 paper

A Comparative Study Between Fetal and Calf Bovine Pericardium

There is a need of a lower profile device of transcatheter heart valves. One way to simply achieve this task is to decrease the size of the device by using a thinner bovine pericardium. The devices currently use calf bovine pericardium which is reported to have a higher tissue thickness compared to that of fetal bovine pericardium. This provided the opportunity to test fetal bovine pericardium as a viable alternative. Uniaxial testing and histology were performed to determine the mechanical and structural properties of both groups (n=10 for each group). We report a statistical difference in ultimate tensile strength and strain at failure between both groups but no statistical difference was found for collagen composition between the two groups. With these results, we are unable to prove fetal bovine pericardium to be a viable alternative. However, there were a couple of outliers from the fetal bovine pericardium had smaller thickness that showed higher ultimate tensile strength and strain at failure compared to those of calf bovine pericardium. In the future, it would provide an opportunity in developing lower profile device by further investigating the cause of this incident.Undergraduat

Optimal developmental test programs for one-shot systems

This dissertation considers two developmental testing models for one-shot systems, non-repairable devices that are destroyed by testing or first normal use (for example, rocket engines) when there is the potential for reliability growth through redesign. Given a limited budget and fixed cost per redesign, we wish to determine the sequence of redesigns and tests so that the expected number of effective systems in an ultimate stockpile of systems of the final design is maximized. We develop mathematical models and analyses which describe the optimal testing policies for this sequential decision problem. Further, we present properties of the models which, in some cases, make the computation of solutions feasible. We begin with the analysis of a two-state reliability model. Besides determining the effect of redesign costs on the optimal strategy, we show how the possibility of harmful redesigns can be incorporated into the model. We explore how this model behaves when even a poor reliability design is highly reliable but extremely high reliability is desired. A primary contribution of the thesis is an analysis of the general multiple-state (k-state) reliability model and, most interestingly, the presentation of a 2-variable formulation by which some k-state models can be analyzed. Under some restrictions, we analyze and compute solutions to this latter model on a lattice

Occupational Ethos of Executive Directors of State Councils on Vocational Education.

The fundamental purpose of this study was to describe the occupational ethos of Executive Directors of State Councils on Vocational Education. As the literature concerning education-related occupational ethos is sparse, the study was an effort to contribute to the literature and to provide an understanding of the occupation of Executive Director of State Councils on Vocational Education. The description of the ethos was derived from two significant viewpoints--orientations and sentiments exhibited by the executive directors. Collection of data for this study was accomplished through two means. The first method involved elite interviewing of a sample of 15 current executive directors to secure their personal characterizations of their work. The second phase involved administration of a survey sent to the entire population of directors. The survey was designed to provide data on the structures of occupational recruitment, socialization and reward. Forty-seven executive directors responded to the survey. The analysis of job recruitment, socialization and reward was aimed at determining orientations that emerged from common themes. Certain attracting aspects of the job were found to influence the recruitment of its potential members. Entry into the position was also found to be facilitated by several common factors. Findings showed that the occupational socialization of directors occurs in two distinct realms--formal training programs and on-the-job experience. Certain non-monetary rewards were found to be significant factors to the work of executive directors. The subsequent analysis concerned executive directors\u27 descriptions of their day-to-day work to determine sentiments held towards this work. Common characteristics were observed relative to the tasks and roles of executive directors. Their portrayal of needed job skills, knowledge and attributes was further studied for identifying themes. The methods of job assessment and indications of job satisfaction as described by the directors provided additional insight into the meanings executive directors attach to their work. The final phase involved synthesizing these orientations, meanings and sentiments to describe the basic elements of the ethos. Two major themes, those of job efficacy and pluralism, emerged from this synthesis of findings

Rational growth in the Heisenberg group

A group presentation is said to have rational growth if the generating series associated to its growth function represents a rational function. A long-standing open question asks whether the Heisenberg group has rational growth for all finite generating sets, and we settle this question affirmatively. We also establish almost-convexity for all finite generating sets. Previously, both of these properties were known to hold for hyperbolic groups and virtually abelian groups, and there were no further examples in either case. Our main method is a close description of the relationship between word metrics and associated Carnot-Caratheodory Finsler metrics on the ambient Lie group. We provide (non-regular) languages in any word metric that suffice to represent all group elements.Comment: Version 2 contains bug fixes and an added application to almost-convexit

Measuring the efficiency of capital allocation in commercial banking

Commercial banks leverage their equity capital with demandable debt that participates in the economy's payments system. The distinctive nature of this debt generates an unusual degree of liquidity risk that can, at times, threaten the payments system. To reduce this threat, insurance protects deposits; and to reduce the moral hazard problems of the debt contract and deposit insurance, bank regulation constrains risk-taking and defines standards of capital adequacy. The inherent liquidity risk of demandable debt as well as potential regulatory penalties for poor financial performance creates the potential for costly episodes of financial distress that affects banks' employment of capital. ; The existence of financial-distress costs implies that many banks are likely to take actions, such as holding additional capital, that increase bank safety at the expense of short-run returns. While such a strategy may reduce average returns in the short run, it may maximize the market value of the bank by protecting charter value and protecting against regulatory interventions. On the other hand, some banks whose charter values are low may have an incentive to follow a higher risk strategy, one that increases average return at the expense of greater risk of financial distress and regulatory intervention. ; This paper examines how banks' employment of capital in their production plans affects their "market value" efficiency. The authors develop a market-based measure of production efficiency and implement it on a sample of publicly traded bank holding companies. Our evidence indicates that banks' efficiency and, hence, the market value of their assets are influenced by the level and allocation of capital. However, even controlling for the effect of size, we find that the influence of equity capital differs markedly between banks with higher capital-to-assets ratios and those with lower ratios. For inefficient banks with higher capital-to-assets ratios, marginal increases in capitalization and asset quality boost their market-value efficiency. For inefficient banks with lower levels of capitalization, the signs of these effects are reversed. Controlling for asset size, it appears that less capitalized banks cannot afford to mimic the investment strategy of more capitalized banks, which may be using this greater capitalization to signal their safety to financial markets.Bank capital