Conformal Field Theory Methods for Variants of Schramm-Loewner Evolutions

This thesis consists of an introduction, four research articles and an appendix. The thesis studies relations between two different approaches to continuum limit of models of two dimensional statistical mechanics at criticality. The approach of conformal field theory (CFT) could be thought of as the algebraic classification of some basic objects in these models. It has been succesfully used by physicists since 1980's. The other approach, Schramm-Loewner evolutions (SLEs), is a recently introduced set of mathematical methods to study random curves or interfaces occurring in the continuum limit of the models. The first and second included articles argue on basis of statistical mechanics what would be a plausible relation between SLEs and conformal field theory. The first article studies multiple SLEs, several random curves simultaneously in a domain. The proposed definition is compatible with a natural commutation requirement suggested by Dubédat. The curves of multiple SLE may form different topological configurations, ``pure geometries''. We conjecture a relation between the topological configurations and CFT concepts of conformal blocks and operator product expansions. Example applications of multiple SLEs include crossing probabilities for percolation and Ising model. The second article studies SLE variants that represent models with boundary conditions implemented by primary fields. The most well known of these, SLE(kappa, rho), is shown to be simple in terms of the Coulomb gas formalism of CFT. In the third article the space of local martingales for variants of SLE is shown to carry a representation of Virasoro algebra. Finding this structure is guided by the relation of SLEs and CFTs in general, but the result is established in a straightforward fashion. This article, too, emphasizes multiple SLEs and proposes a possible way of treating pure geometries in terms of Coulomb gas. The fourth article states results of applications of the Virasoro structure to the open questions of SLE reversibility and duality. Proofs of the stated results are provided in the appendix. The objective is an indirect computation of certain polynomial expected values. Provided that these expected values exist, in generic cases they are shown to possess the desired properties, thus giving support for both reversibility and duality.

Signal set design for full-diversity low-decoding-complexity differential scaled-unitary STBCs

The problem of designing high rate, full diversity noncoherent space-time block codes (STBCs) with low encoding and decoding complexity is addressed. First, the notion of g-group encodable and g-group decodable linear STBCs is introduced. Then for a known class of rate-1 linear designs, an explicit construction of fully-diverse signal sets that lead to four-group encodable and four-group decodable differential scaled unitary STBCs for any power of two number of antennas is provided. Previous works on differential STBCs either sacrifice decoding complexity for higher rate or sacrifice rate for lower decoding complexity.

Disallowed Ramachandran Conformations of Amino Acid Residues in Protein Structures

An analysis of the nature and distribution of disallowed Ramachandran conformations of amino acid residues observed in high resolution protein crystal structures has been carried out. A data set consisting of 110 high resolution, non-homologous, protein crystal structures from the Brookhaven Protein Data Bank was examined. The data set consisted of a total of 18,708 non-Gly residues, which were characterized on the basis of their backbone dihedral angles (φ, ψ). Residues falling outside the defined “broad allowed limits” on the Ramachandran map were chosen and the reportedB-factor value of the α-carbon atom was used to further select well defined disallowed conformations. The conformations of the selected 66 disallowed residues clustered in distinct regions of the Ramachandran map indicating that specific φ, ψ angle distortions are preferred under compulsions imposed by local constraints. The distribution of various amino acid residues in the disallowed residue data set showed a predominance of small polar/charged residues, with bulky hydrophobic residues being infrequent. As a further check, for all the 66 cases non-hydrogen van der Waals short contacts in the protein structures were evaluated and compared with the ideal “Ala-dipeptide” constructed using disallowed dihedral angle (φ, ψ) values. The analysis reveals that short contacts are eliminated in most cases by local distortions of bond angles. An analysis of the conformation of the identified disallowed residues in related protein structures reveals instances of conservation of unusual stereochemistry.

Solution of MDPS using simulation-based value iteration

This article proposes a three-timescale simulation based algorithm for solution of infinite horizon Markov Decision Processes (MDPs). We assume a finite state space and discounted cost criterion and adopt the value iteration approach. An approximation of the Dynamic Programming operator T is applied to the value function iterates. This 'approximate' operator is implemented using three timescales, the slowest of which updates the value function iterates. On the middle timescale we perform a gradient search over the feasible action set of each state using Simultaneous Perturbation Stochastic Approximation (SPSA) gradient estimates, thus finding the minimizing action in T. On the fastest timescale, the 'critic' estimates, over which the gradient search is performed, are obtained. A sketch of convergence explaining the dynamics of the algorithm using associated ODEs is also presented. Numerical experiments on rate based flow control on a bottleneck node using a continuous-time queueing model are performed using the proposed algorithm. The results obtained are verified against classical value iteration where the feasible set is suitably discretized. Over such a discretized setting, a variant of the algorithm of [12] is compared and the proposed algorithm is found to converge faster.

Effect of boundary condition description on convergence of solution in a boundary-value problem

It is well known that the numerical accuracy of a series solution to a boundary-value problem by the direct method depends on the technique of approximate satisfaction of the boundary conditions and on the stage of truncation of the series. On the other hand, it does not appear to be generally recognized that, when the boundary conditions can be described in alternative equivalent forms, the convergence of the solution is significantly affected by the actual form in which they are stated. The importance of the last aspect is studied for three different techniques of computing the deflections of simply supported regular polygonal plates under uniform pressure. It is also shown that it is sometimes possible to modify the technique of analysis to make the accuracy independent of the description of the boundary conditions.

The elastic properties of a group of optical glasses by the pulse echo set-up

The pulse-echo apparatus, designed and constructed by the author, has been used to reinvestigate the elastic properties of the eighteen optical glasses. The elastic constants are correct to 0·5%. The results are compared with the earlier investigation which utilised the optical method. The possible causes for large discrepancies observed are critically and briefly discussed. A qualitative interpretation of the results has been successfully attempted. The acoustic velocity increases with the decrease in lead and barium oxides and with increase in calcium oxide and boron trioxide components.

Heat transfer in rarefied couette flow on the basis of discrete ordinate method

The method of discrete ordinates, in conjunction with the modified "half-range" quadrature, is applied to the study of heat transfer in rarefied gas flows. Analytic expressions for the reduced distribution function, the macroscopic temperature profile and the heat flux are obtained in the general n-th approximation. The results for temperature profile and heat flux are in sufficiently good accord both with the results of the previous investigators and with the experimental data.

Convergence correction in colloid scattering

The error introduced in depolarisation measurements due to the convergence of the incident beam has been investigated theoretically as well as experimentally for the case of colloid scattering, where the particles are not small compared to the wavelength of light. Assuming the scattering particles to be anisotropic rods, it is shown that, when the incident unpolarised light is condensed by means of a lens with a circular aperture, the observed depolarisation ratio ϱ u is given by ϱ u = ϱ u0 + 5/3 θ2 where ϱ u0 is the true depolarisation for incident parallel light, and θ the semi-angle of convergence. Appropriate formulae are derived when the incident beam is polarised vertically and horizontally. Experiments performed on six typical colloids support the theoretical conclusions. Other immediate consequences of the theory are also discussed.

European Union and the developing nations' external debt : EU-15's debt policy, 1960–2008

This Master's Thesis defines the debt policy of the current European Union Member States towards the developing nations. Since no official policy for debt exists in the EU, it is defined to include debt practices (loans and debt relief in development cooperation) and debt within the EU development policy framework. This study (1) describes how the issue of external debt appears in the development policy framework, (2) compares EU Member States' given loans and debt relief to grants for the developing nations (1960s to the 2000s), and (3) measures the current orientation in ODA of each EU Member State between grant aid and loan aid using the Grant-Loan Index (GLI). Theoretical aspects include reasons for selecting between loans (Bouchet 1987) and grants (Odedokun 2004, O'Brien and Williams 2007), policy context of the EU (Van Reisen 2007) and the meaning of external debt in the set-up between the North and the South. In terms of history, the events and impact of the colonial period (where loans have originated) are overviewed and compared in light of today's policies. Development assistance statistics are derived from the OECD DAC statistics portal and EU development policy framework documents from the EU portal. Methodologically, the structure of this study is from policy analysis (Barrien 1999, Hill 2008, Berndtson 2008), but it has been modified to fit the needs of studying a non-official policy. EU Member States are divided into three groups by Carbone (2007a), the Big-3, Northern and Southern donors, based on common development assistance characteristics. The Grant-Loan Index is used to compare Carbone's model, which measures quality of aid, to the GLI measuring the structure of aid. Results indicate that EU- 15 countries (active in debt practices) differ in terms of timing, stability and equality of debt practices in the long-term (1960s to the 2000s). In terms of current practices, (2000-2008), it is noted that there lies a disparity between the actual practices and the way in which external debt is represented in the development policy framework, although debt practices form a relevant portion of total ODA practices for many EU-15 Member States, the issue itself plays a minor role in development policy documents. Carbone’s group division applies well to the Grant – Loan Index’s results, indicating that countries with similar development policy behaviour have similarities in debt policy behaviour, with one exception: Greece. On the basis of this study, it is concluded that EU development policy framework content in terms of external debt and debt practices are not congruent. The understanding of this disparity between the policy outline and differences in long-term practices is relevant in both, reaching the UN’s Millennium Development Goals, and in the actual process of developing development aid.

Elastic behaviour of matter under very high pressures - Uniform compression

In order to study the elastic behaviour of matter when subjected to very large pressures, such as occur for example in the interior of the earth, and to provide an explanation for phenomena like earthquakes, it is essential to be able to calculate the values of the elastic constants of a substance under a state of large initial stress in terms of the elastic constants of a natural or stress-free state. An attempt has been made in this paper to derive expressions for these quantities for a substance of cubic symmetry on the basis of non-linear theory of elasticity and including up to cubic powers of the strain components in the strain energy function. A simple method of deriving them directly from the energy function itself has been indicated for any general case and the same has been applied to the case of hydrostatic compression. The notion of an effective elastic energy-the energy require to effect an infinitesimal deformation over a state of finite strain-has been introduced, the coefficients in this expression being the effective elastic constants. A separation of this effective energy function into normal co-ordinates has been given for the particular case of cubic symmetry and it has been pointed out, that when any of such coefficients in this normal form becomes negative, elastic instability will set in, with associated release of energy.

The Contested Terrain of Globalization: Review and Conceptual Clarifications for Management Studies

The concept of globalization has become a shorthand for making sense of contemporary society. It reflects large-scale economic and social change, which affects people differently and evokes different viewpoints. Globalization is thus a highly contested concept and phenomenon. Contradictory and competing views, in turn, seem to be based on different interpretations of the present dominant forms of globalization, and of the material, economic, social and cultural conditions that these forms produce and give rise to. We view globalization not only as a significant set of economic, financial, social, political and cultural forces but as a powerful and contested discursive space. In this article, we present an overview of recent literature to introduce different thematic perspectives on globalization, to specify different ideological and discursive bases to approach globalization, and to place multinational corporations (MNC:s) within this context. Our account is not exhaustive, rather, it is intended as a basis for further discussion on the nature and role of multinational corporations in complex ”global” society

Molecular Basis for the Role of Staphylococcus aureus Penicillin Binding Protein 4 in Antimicrobial Resistance

Penicillin binding proteins (PBPs) are membrane-associated proteins that catalyze the final step of murein biosynthesis. These proteins function as either transpeptidases or carboxypeptidases and in a few cases demonstrate transglycosylase activity. Both transpeptidase and carboxypeptidase activities of PBPs occur at the D-Ala-D-Ala terminus of a murein precursor containing a disaccharide pentapeptide comprising N-acetyl-glucosamine and N-acetyl-muramic acid-L-Ala-D-Glu-L-Lys-D-Ala-D-Ala. beta-Lactam antibiotics inhibit these enzymes by competing with the pentapeptide precursor for binding to the active site of the enzyme. Here we describe the crystal structure, biochemical characteristics, and expression profile of PBP4, a low-molecular-mass PBP from Staphylococcus aureus strain COL. The crystal structures of PBP4-antibiotic complexes reported here were determined by molecular replacement, using the atomic coordinates deposited by the New York Structural Genomics Consortium. While the pbp4 gene is not essential for the viability of S. aureus, the knockout phenotype of this gene is characterized by a marked reduction in cross-linked muropeptide and increased vancomycin resistance. Unlike other PBPs, we note that expression of PBP4 was not substantially altered under different experimental conditions, nor did it change across representative hospital- or community-associated strains of S. aureus that were examined. In vitro data on purified recombinant S. aureus PBP4 suggest that it is a beta-lactamase and is not trapped as an acyl intermediate with beta-lactam antibiotics. Put together, the expression analysis and biochemical features of PBP4 provide a framework for understanding the function of this protein in S. aureus and its role in antimicrobial resistance.

Growth and Convergence: The case of China

Growth and Convergence: The Case of China Since the initiation of economic reforms in 1978, China has become one of the world’s fast-growing economies. The rapid growth, however, has not been shared equally across the different regions in China. The prominent feature of substantial differences in incomes and growth rates across the different Chinese regions has attracted the attention of many researchers. This book focuses on issues related to economic growth and convergence across the Chinese regions over the past three decades. The book has eight chapters. Apart from an introduction chapter and a concluding chapter, all the other chapters each deal with some certain aspects of the central issue of regional growth and convergence across China over the past three decades. The whole book is organized as follows. Chapter 1 provides an introduction to the basic issues involved in this book. Chapter 2 tests economic growth and convergence across 31 Chinese provinces during 1981-2005, based on the theoretical framework of the Solow growth model. Chapter 3 investigates the relationship between openness to foreign economic activities, such as foreign trade and foreign direct investment, and the regional economic growth in the case of China during 1981-2005. Chapter 4, based on data of 31 Chinese provinces over the period 1980-2004, presents new evidence on the effects of structural shocks and structural transformation on growth and convergence among the Chinese regions. Chapter 5, by building up an empirical model that takes account of different potential effects of foreign direct investment, focuses on the impacts of foreign direct investment on China’s regional economic performance and growth. Chapter 6 reconsiders the growth and convergence problem of the Chinese regions in an alternative theoretical framework with endogenous saving behavior and capital mobility across regions. Chapter 7, by building up a theoretical model concerning comparative advantage and transaction efficiency, focuses on one of the potential mechanisms through which China achieves its fast economic growth over the past few decades. Chapter 8 concludes the book by summarizing the results from the previous chapters and suggesting directions for further studies.

The Gendered Social Organisation of Defence: Two Ethnographic Case Studies in the Finnish Defence Forces

In Finland the organising of defence is undergoing vast restructuring. Recent legislation has redefined the central tasks of the Finnish Defence Forces. At the same time, international security cooperation, economic pressures and new administrative paradigms have steered the military towards new ways of organising. National defence is not just politics and principles; to a large extent it is also enacted in day-to-day life in organisations. The lens through which these realities of defence are analysed in this study is gender. How is the security sector – and national defence as part of it – organised in the changing security environment? What is the new division of labour between different societal actors in the face of security challenges? What happens ‘at work’ within the military and the defence sector more broadly? How does gender affect the way in which defence is organised and understood, and how do the changes in the organising of security affect gender relations? The thesis searches for answers to these questions in the context of two organisational settings in the male-dominated defence sector. The case study on a Finnish peacekeeping unit in the Balkans opens a critical view on men’s social practices and the everyday life of crisis management organisations. In the second case study, reorganising of provisioning in the Finnish Defence Forces turns out to be a complicated process where different power relations and social divisions intermingle. Tallberg’s extensive ethnographic fieldwork in the two focal organisations has produced a detailed set of data that lays the basis for critical analysis and policy development in terms of defence organising, cooperation around peace and security issues, and gender equality in organisations. Observations and results are provided for understanding social networks, militarisation, authority relations, care, public-private partnerships, personnel policies, career planning, and humour.