Thesis advisor: David A. Broido / A theory is presented for describing the lattice thermal conductivities of graphene and single-walled carbon nanotubes. A phonon Boltzmann transport equation approach is employed to describe anharmonic phonon-phonon, crystal boundary, and isotopic impurity scattering. Full quantum mechanical phonon scattering is employed and an exact solution for the linearized Boltzmann transport equation is determined for each system without use of common relaxation time and long-wavelength approximations. The failures of these approximations in describing the thermal transport properties of nanotubes is discussed. An efficient symmetry based dynamical scheme is developed for carbon nanotubes and selection rules for phonon-phonon scattering in both graphene and nanotubes are introduced. The selection rule for scattering in single-walled carbon nanotubes allows for calculations of the thermal conductivities of large-diameter and chiral nanotubes that could not be previously studied due to computational limitations. Also due to this selection rule, no acoustic-only umklapp scattering can occur, thus, acoustic-optic scattering must be included in order to have thermal resistance from three-phonon processes. The graphene selection rule severely restricts phonon-phonon scattering of out-of-plane modes. This restriction leads to large contributions to the total thermal conductivity of graphene from the acoustic, out-of-plane modes which have been previously neglected. Empirical potentials used to model interactions in carbon-based materials are optimized to better describe the lattice dynamics of graphene-derived systems. These potentials are then used to generate the interatomic force constants needed to make calculations of the thermal conductivities of graphene and carbon nanotubes. Calculations of the thermal conductivities of single-walled carbon nanotubes and graphene for different temperatures and lengths are presented. The thermal conductivities of SWCNTs saturate in the diffusive regime when the effects of higher-order scattering processes are estimated and correctly reproduce the ballistic limit for short-length nanotubes at low temperatures. The effects of isotopic impurity scattering on the thermal conductivities of graphene and SWCNTs are explored. Isotopic impurities have little effect in the low (high) temperature regime where boundary (umklapp) scattering dominates the behavior of the thermal conductivities. In the intermediate temperature regime, modest reductions in the thermal conductivities, 15-20%, occur due to impurities. The thermal conductivities of a wide-range of SWCNTs are explored. The thermal conductivities of successively larger-diameter, one-dimensional nanotubes approach the thermal conductivity of two-dimensional graphene. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

This report represents the next step of Enterprise Resource Planning (ERP)related research at the Department of Information Business at the Vienna University of Economics and Business Adminstration following previous work on the selection process. Based on 209 datasets originating from a primary, national and industry independent survey, it provides a descriptive oriented overview of main characteristics of ERP in all stages of the system's lifecycle, emphasising differences between small-to-medium sized and large enterprises (SMEs and LEs). The given research topics in particular comprise software diffusion, resources allocated, strategic project guidance, investment drivers, considered and chosen solutions, team structures, selection criteria, information gathering, methodical support, implementation approaches, acompanying business strategies, implementation problems, perceived utilisation of ERP benefits, firm level ERP impact, and the role of ERP systems as technology enabler. Future work based on the gathered data will document analytical projects undertaken in particular focusing on ERP success, enterprise integration, organisational fit of ERP, and BPR/BPI related questions. / Series: Working Papers on Information Systems, Information Business and Operations

This thesis examines the effects income inequality has on economic growth, drawing on data from China. It focuses on two related questions: whether income inequality is harmful to economic growth and, if so, why. The first empirical chapter uses a newly-developed panel dataset at the province level to examine the long-run impact of income inequality on economic growth, addressing the problem of spurious regression that affects much of the existing literature. The empirical results indicate that the long-run effect of income inequality on economic growth is non-linear: while income inequality exerts a positive impact on economic growth for rich provinces, it is harmful to economic growth for poor regions. The second empirical chapter provides mathematical and empirical evidence that demonstrates the deficiencies in existing studies that solely rely on macroeconomic data. It examines three mainstream transmission mechanisms by using data at both the household and village level. At the village level, the empirical results show that income inequality leads to lower economic growth. However, at the household level, income inequality is positively linked to income growth for households with low levels of initial income. Such seemingly contradictory results agree with the predictions of my mathematical example and suggest that the political economy channel is responsible for the inequality-growth relationship in rural China. The last empirical chapter examines whether inequality and growth are linked across generations by evaluating the impact of the One Child Policy on fertility and education in China. Using a difference-in-differences approach, the empirical results suggest that the One Child Policy successfully lowered the probability of having a child for Han women and increased the probability of attending school for Han children. This empirical evidence indicates that the endogenous fertility channel operates in China.

En 2011, des mouvements sociaux et révolutionnaires d’une ampleur rare ont agité certains pays du nord de l’Afrique. Cela correspond à ce qu’on a appelé le printemps arabe.Le premier de ces pays touchés par ces mouvements est la Tunisie. Cette thèse porte sur la révolution tunisienne. Elle propose une analyse théorique et empirique de cette révolution.D’un point de vue théorique, ce travail se situe dans le cadre de l’analyse économique. Nous nous situons donc dans le prolongement de la littérature économique qui, à partir des années 1970, s’est intéressée aux mouvements sociaux et plus précisément les révolutions. La théorie économique a offert un autre cadre permettant d’analyser la manière dont l’action d’un petit groupe d’individus peut provoquer des bouleversements de grande envergure. L’un des objets de cette thèse est alors de proposer une synthèse de cette littérature. Nous soulignons que cette thèse revient sur les définitions de la révolution et propose une présentation qui essaye d’être exhaustive des analyses économiques des révolutions. Quatre types de modèles sont définis : la méthode décisionnelle, la théorie des jeux, la méthode d'analyse Tobit et le modèle seuil de mobilisation. Ces modèles ont parvenu à expliquer l’émergence d’un mouvement révolutionnaire mais ne prennent pas en compte la particularité de chaque pays, nous insistons en particulier sur ce point. Il n’en est pas moins vrai que, la littérature théorique sur les révolutions a précisé ce caractère unique pour chaque révolution. Autour de cette spécificité, l’idée centrale de cette thèse a été construite : quelles sont les causes de la révolution tunisienne ? En outre, la contribution principale de cette thèse est d’ordre empirique. Bien que de nombreuses recherches aient analysé de différentes manières les causes des révolutions (Données de panel, modèles économétriques), la méthode d’analyse en composantes principales (ACP) est, à notre connaissance, la première contribution dans l’analyse des révolutions et surtout la première étude de ce type appliquée à la Tunisie. Cette méthode a pu détecter trois ramifications caractérisant le 14 janvier 2011. Trois révolutions d’ordre sociologique et sociétal semblent particulièrement importantes : une révolution démographique, une révolution de l’alphabétisation et une révolution des attentes. Premièrement, la transition démographique et ses implications économiques et sociales. Deuxièmement, les inégalités et l’élargissement de la fracture sociale entre les régions. Troisièmement, la mauvaise gestion du pays suite à l’emprise de l’économie sous Ben Ali et ses conséquences catastrophique sur l’investissement et la création d’emplois. / Revolution, which embodies major turns in the course of history, has for a long time been a social study subject. With the coming of the school of public choice in the 1960's, a new economic current helped to undestand revolution. Many economists such as: James M. Buchanan (1962), Gordon Tullock (1971-1974) and John E. Romer (1985) have applied economic theory to social and political science using tools developed by microeconomy. The goal of my research paper is to highlight the contribution of economic theory in the understanding of revolution. I have first drawn a line between two approaches that have studied revolution: The sociological approach which mainly explains why do people revolt when they are faced with structural imbalances. The economic approach which uses the theory of rational choice to demonstrate how people choose to be passive when they are confronted with a revolution.

A number of techniques for indoor and outdoor WiFi localization using received signal strength (RSS) signatures have been published. Little work has been performed to characterize the RSS signatures used by these WiFi localization techniques or to assess the accuracy of current channel models to represent the signatures. Without accurate characterization and models of the RSS signatures, a large amount of empirical data is needed to evaluate the performance of the WiFi localization techniques. The goal of this research is to characterize the RSS signatures, propose channel model improvements based on the characterization, and study the performance of channel models for use in WiFi localization simulations to eliminate the need for large amounts of empirical data measurements. In this thesis, we present our empirical database of RSS signatures measured on the Worcester Polytechnic Institute campus. We use the empirical database to characterize the RSS signatures used in WiFi localization, showing that they are composed of connective segments and influenced by the access point (AP) location within a building. From the characterization, we propose improving existing channel models by building partitioning the signal path-loss using site-specific information from Google Earth. We then evaluate the performance of the existing channel models and the building partitioned models against the empirical data. The results show that using site-specific information to building partition the signal path-loss a tighter fit to the empirical RSS signatures can be achieved.

The present master thesis deals with non-banking microfinance institutions and examines its abilities and role in the poverty alleviation process. It is more than necessary to pay attention to the rural sector and its development as any successful transition of the economy requires transition of the rural sector as well. In many transition economies people in the rural areas continue to live on the edge of poverty, engaged in subsistence agriculture and remain susceptible to wide range of shocks. In such countries rural population unlike urban one did not benefit to the same extend from transition and need special attention and supporting policy measures. Due to low penetration rate of microfinance institutions into rural areas, lacking or insufficient size of collateral, financial illiteracy many poor but active man face problems to obtaining finance for the development of new income opportunities. In this context the master thesis emphasizes the role of savings and credit associations, which unlike the commercial banks operate mainly in rural sector, have the most significant effect on poverty alleviation. Finally, the author analyses the activity of 3 non-banking microfinance institutions of the Republic of Moldova and uses publicly available data to calculate the outreach, efficiency and...

Programming is a valuable skill in the labor market, making the underrepresentation of women in computing an increasingly important issue. Online question and answer platforms serve a dual purpose in this field: they form a body of knowledge useful as a reference and learning tool, and they provide opportunities for individuals to demonstrate credible, verifi- able expertise. Issues, such as male-oriented site design or overrepresentation of men among the site's elite may therefore compound the issue of women's underrepresentation in IT. In this paper we audit the differences in behavior and outcomes between men and women on Stack Overflow, the most popular of these Q&A sites. We observe significant differences in how men and women participate in the platform and how successful they are. For example, the average woman has roughly half of the reputation points, the primary measure of success on the site, of the average man. Using an Oaxaca-Blinder decomposition, an econometric technique commonly applied to analyze differences in wages between groups, we find that most of the gap in success between men and women can be explained by differences in their activity on the site and differences in how these activities are rewarded. Specifically, 1) men give more answers than women and 2) are rewarded more for their answers on aver age, even when controlling for possible confounders such as tenure or buy-in to the site. Women ask more questions and gain more reward per question. We conclude with a hypo thetical redesign of the site's scoring system based on these behavioral differences, cutting the reputation gap in half.

In this dissertation, we provide empirical assessment of government involvement in economic activities. This assessment is done within the framework of a two-part strategy. In the first part, we evaluate the effects of the government size on the overall rate of economic growth of a group of 30 developing countries. This approach can be regarded as macroeconomic in the sense that the economywide growth is the subject of investigation. In the second part, we conducted a comparative study of technical efficiency between privately owned and publicly owned companies in the international oil industry. We refer to this approach as microeconomic since a particular industry is under investigation. this dissertation consists of two essays. In the first essay, we examine the effect of government size, measured by the ratio of government consumption expenditures to gross domestic product (GDP) on the rate growth of GDP. Our sample includes 30 low-income and middle-income developing countries over the period 1970-90. We use a panel data approach to avoid the shortcomings of the cross-country models often used in such an analysis. The results indicate government size has a highly significant negative influence on the rate of economic growth. Therefore, privatization is viewed as a structural adjustment policy to overcome the negative effects of government size. However, we emphasize this policy can be effective only in the proper environment in a market-oriented economy with well-established political, social, and economic institutions, and a well-defined property right system. The essay provides some empirical evidence from a group of countries about the impact of privatization on the rate of economic growth. In the second essay, we measure the firm-specific technical efficiency for a sample of 44 publicly owned and privately owned petroleum companies in the international oil industry. The empirical investigation is carried out by using the stochastic frontier production function approach. The results indicate the private decision-making units in the oil industry overperformed their publicly owned counterparts in terms of technical efficiency. The implication is privatization can improve the performance of the transformed public enterprises.

Metallised polypropylene (MPP) capacitors, the dominant capacitor type used in a wide range of power and electronic circuit applications, offer high volumetric capacitor density, low cost, excellent frequency characteristics and a unique ability to recover from point failures in the dielectric film. However MPP capacitors have a generic weakness that is not well understood, failure of the self-healing process leading to ongoing catastrophic failure. The work described in this thesis includes the derivation of an improved electrical model of a capacitor and the uncovering of a mechanism for the catastrophic failure mode. Corrosion of the thin metallic field is firmly linked to drastic increases in metal film current densities and generation of hot spots in capacitors. In the work, novel formulae were derived relating capacitor parameters such as equivalent series resistance and equivalent series capacitance to frequency and physical characteristics such as metal film resistivity and physical dimensions of multiple layer capacitors. Modelling using numerical methods and diffusion equation showed that capacitors with double-end connection topology have more uniform voltage and power distribution than single-end connected capacitors. External characteristics of both connection topologies were shown to be virtually identical up to frequencies well above typical self-resonance. The aggregate spatial distribution of power from both layers and the voltage across the dielectric were found to be fundamentally different in the two circuit connection topologies. In this work it was shown that above singularity frequencies defined by distributed capacitance and metal film spreading resistance, equivalent series resistance and capacitance both fall with the square root of frequency Analysis of the inductance of typical MPP capacitors for single-end and double-end connected topologies and for circumferentially connected capacitor metallization showed that the magnitude and effect of distributed inductance in typical MPP power capacitors was insignificant compared to packaging inductance. Thermal and electrical modelling and experimental measurements showed that corrosion effects could readily account for the generic catastrophic failure mode of metallised polypropylene capacitors. Modelling showed that remnant vestiges of metal bridging corrosion gaps between the schooping and the metallic film could also pose serious thermal danger to the affected capacitor. Fusing current modelling and experimental measurement showed that fusing in metallic films typically occurred for current densities of several hundred thousand amperes per square centimetre. The partial disconnection of the metallic layers from the schooping edge by corrosion for example, was shown to result in large increases in dissipation factor and power loss in a capacitor readily explaining how capacitors

<p>Background One of the main demands on Swedish and global health care in general is to meet the patient’s need for safety. By general health care law this also comprises district nurses’ field of responsibility. Although there are numerous studies describing the concept of safety and its different shapes, no research could be found exploring how safety is, or supposed to be, mediated by district nurses’ in a Swedish context. Research about this is therefore needed. Aim The aim of this qualitative study was to explore how district nurses’ mediate safety to their patients. Method Qualitative data were collected from seven district nurses’ by means of semi structured interviews. Thereafter, a concept analysis was carried out. Results Responses revealed that district nurses’ consider themselves mediate safety through a variety of ways. Five major categories emerged: (1) complaisance’s; (2) competence; (3) patient participation; (4) same caregiver; (5) personal characteristics. Conclusion District nurses’ mediate safety through a combination of general attitudes and concrete acts. Preconditions are bound to each district nurse’s individual ability to give a good complaisance, his/her competence and ability to involve patients in treatment and care. Other, less pronounced, are bound to the district nurse’s ability to create continuity in contact with patients’ and his/her personal characteristics.</p>