VictorJuiz/thesis huggingface dataset:
Mathematical evolutionary epidemiology: limited epitopes, evolution of strain structures and age-specificity

We investigate the biological constraints determined by the complex relationships between ecological and immunological processes of host-pathogen interactions, with emphasis on influenza viruses in human, which are responsible for a number of pandemics in the last 150 years. We begin by discussing prolegomenous reviews of historical perspectives on the use of theoretical modelling as a complementary tool in public health and epidemiology, current biological background motivating the objective of the thesis, and derivations of mathematical models of multi-locus-allele systems for infectious diseases with co-circulating serotypes. We provide detailed analysis of the multi-locus-allele model and its age-specific extension. In particular, we establish the necessary conditions for the local asymptotic stability of the steady states and the existence of oscillatory behaviours. For the age-structured model, results on the existence of a mild solution and stability conditions are presented. Numerical studies of various strain spaces show that the dynamic features are preserved. Specifically, we demonstrate that discrete antigenic forms of pathogens can exhibit three distinct dynamic features, where antigenic variants (i) fully self-organize and co-exist with no strain structure (NSS), (ii) sort themselves into discrete strain structure (DSS) with non-overlapping or minimally overlapping clusters under the principle of competitive exclusion, or (iii) exhibit cyclical strain structure (CSS) where dominant antigenic types are cyclically replaced with sharp epidemics dominated by (1) a single strain dominance with irregular emergence and re-emergence of certain pathogenic forms, (2) ordered alternating appearance of a single antigenic type in periodic or quasi-periodic form similar to periodic travelling waves, (3) erratic appearance and disappearance of synchrony between discrete antigenic types, and (4) phase-synchronization with uncorrelated amplitudes. These analyses allow us to gain insight into the age-specific immunological profile in order to untangle the effects of strain structures as captured by the clustering behaviours, and to provide public health implications. The age-structured model can be used to investigate the effect of age-specific targeting for public health purposes.

Keywords: influenza
age-specificity
mathematical biology
age-structured model
infectious diseases
strain structure
antigenic variation
Advisor: Maini, P
Gupta, S
Dyson, J
Mathematical methods for valuation and risk assessment of investment projects and real options

In this thesis, we study the problems of risk measurement, valuation and hedging of financial positions in incomplete markets when an insufficient number of assets are available for investment (real options). We work closely with three measures of risk: Worst-Case Scenario (WCS) (the supremum of expected values over a set of given probability measures), Value-at-Risk (VaR) and Average Value-at-Risk (AVaR), and analyse the problem of hedging derivative securities depending on a non-traded asset, defined in terms of the risk measures via their acceptance sets. The hedging problem associated to VaR is the problem of minimising the expected shortfall. For WCS, the hedging problem turns out to be a robust version of minimising the expected shortfall; and as AVaR can be seen as a particular case of WCS, its hedging problem is also related to the minimisation of expected shortfall. Under some sufficient conditions, we solve explicitly the minimal expected shortfall problem in a discrete-time setting of two assets driven by correlated binomial models. In the continuous-time case, we analyse the problem of measuring risk by WCS, VaR and AVaR on positions modelled as Markov diffusion processes and develop some results on transformations of Markov processes to apply to the risk measurement of derivative securities. In all cases, we characterise the risk of a position as the solution of a partial differential equation of second order with boundary conditions. In relation to the valuation and hedging of derivative securities, and in the search for explicit solutions, we analyse a variant of the robust version of the expected shortfall hedging problem. Instead of taking the loss function l(x)=[x]+ we work with the strictly increasing, strictly convex function Lϵ(x)=ϵlog(
1+exp{−x/ϵ}
exp{−x/ϵ}
). Clearly limϵ→0Lϵ(x)=l(x). The reformulation to the problem for L_{\epsilon}(x) also allow us to use directly the dual theory under robust preferences recently developed in [82]. Due to the fact that the function Lϵ(x) is not separable in its variables, we are not able to solve explicitly, but instead, we use a power series approximation in the dual variables. It turns out that the approximated solution corresponds to the robust version of a utility maximisation problem with exponential preferences (U(x)=−
1
γ
e−γx) for a preferenes parameter γ=1/ϵ. For the approximated problem, we analyse the cases with and without random endowment, and obtain an expression for the utility indifference bid price of a derivative security which depends only on the non-traded asset.
Flexible repression: engineering control and contention in authoritarian China

How do authoritarian states foster civil society growth while keeping unruly organizations in line? This governance dilemma dogs every state that attempts to modernize by permitting civil society to pluralize while minding its potential to stir up restive social forces. This dissertation’s main finding is that the Chinese party-state— the world’s largest and arguably the most resilient authoritarian regime—has engineered a flexible institution of state control in which the “rules of the game” are created, disseminated, and enforced outside of institutionalized channels. This dissertation demonstrates how the coercive apparatus improvises in an erratic manner, unfettered by accountability mechanisms.
The regime does not necessarily pull the levers of hard control mechanisms—the tanks, guns, and tear gas—whenever dissenters cross a line of political acceptability. Instead, in keeping with its decentralized political system and its tradition of experimental policy-making, the Chinese state continually remakes the rules of the game which keeps potential rabble-rousers on their toes. Although the regulatory skeleton of state corporatism remains intact, flexible repression is the informal institution—the set of rules and procedures—that structures state-civil society interactions. Specifically, this institution is made up of three key practices: a) decentralization b) ad-hoc deployment c) mixed control strategies. These three practices manifest in two concrete strategies used to govern aboveground and underground civil society: fragmented coercion and controlled competition. Flexible repression enables the Chinese party-state to exploit the advantages of a flourishing third sector while curtailing its threatening potential.
Through participant observation, interviews, and comparative case studies of aboveground and underground independent labor organizations, this dissertation accomplishes three goals. First, it identifies the within-country variation in state control strategies over civil society, which includes the above-ground sector as well as the underground sector of ostensibly banned organizations. Secondly, it traces the patterns of interactions between the state and civil society, generating hypotheses about the mechanisms of change. Finally, it identifies new concepts relevant for studying organized contention in authoritarian regimes. Overall, this dissertation contributes to the study of authoritarian state control and civil society contention, with an emphasis on the nexus between the two.

Keywords: contentious politics
civil society
state-society relations
authoritarian politics
labor organizations
Chinese politics
Advisor: Shue, V
Murphy, R
Insolvency and reform of English bankruptcy law, 1831-1914

This thesis is a history of the reform of English bankruptcy law 1831-1914 and a statistical analysis of the insolvency the reforms sought to limit. The first two chapters describe the historiography of government growth in nineteenth-century Britain and outline the history of English bankruptcy legislation until 1831. Using statistics from bankruptcy reports published by the Board of Trade after 1883 and returns issued by other government entities prior to that date, chapters three and four define the extent and the characteristics of insolvency. These chapters analyze the aggregate level of bankruptcy in particular occupations and geographic areas; they also examine the effect of trade cycles on bankruptcy levels, both in terms of numbers of bankruptcies and losses occasioned. The remaining chapters trace the history of bankruptcy legislation and examine why Parliament embraced the concept of government supervision of bankrupt estates in 1831, then dismantled the system in the 1860s, only to reimpose it once again a short time later. The roles of three groups in this story -- the business community, the legal profession, and the government -- are examined in detail using the records of the local chambers of commerce, law societies, and other organizations.
The thesis concludes that, while the aggregate level of losses declined after the Bankruptcy Act of 1883, the loss rates for some occupations did not reflect this decline. Also, trade cycles did not uniformly affect the rate of bankruptcy for all occupations and geographic areas. Random factors rather than trade cycles had the greatest effect on annual bankruptcy rates. The thesis also argues that the extension of government brought about by bankruptcy reforms was largely a pragmatic attempt to manage bankrupt estates efficiently and had little philosophical basis. Further, the close resemblances between bankruptcy reforms and other Victorian extensions of government add to the evidence that, while there may not be a strict pattern to government growth, such growth may be considered as a distinct and identifiable process.
Biomimetic and autonomic server ensemble orchestration

This thesis addresses orchestration of servers amongst multiple co-hosted internet services such as e-Banking, e-Auction and e-Retail in hosting centres. The hosting paradigm entails levying fees for hosting third party internet services on servers at guaranteed levels of service performance. The orchestration of server ensemble in hosting centres is considered in the context of maximising the hosting centre's revenue over a lengthy time horizon.
The inspiration for the server orchestration approach proposed in this thesis is drawn from nature and generally classed as swarm intelligence, specifically, sophisticated collective behaviour of social insects borne out of primitive interactions amongst members of the group to solve problems beyond the capability of individual members. Consequently, the approach is self-organising, adaptive and robust.
A new scheme for server ensemble orchestration is introduced in this thesis. This scheme exploits the many similarities between server orchestration in an internet hosting centre and forager allocation in a honeybee (Apis mellifera) colony. The scheme mimics the way a honeybee colony distributes foragers amongst flower patches to maximise nectar influx, to orchestrate servers amongst hosted internet services to maximise revenue. The scheme is extended by further exploiting inherent feedback loops within the colony to introduce self-tuning and energy-aware server ensemble orchestration.
In order to evaluate the new server ensemble orchestration scheme, a collection of server ensemble orchestration methods is developed, including a classical technique that relies on past history to make time varying orchestration decisions and two theoretical techniques that omnisciently make optimal time varying orchestration decisions or an optimal static orchestration decision based on complete knowledge of the future.
The efficacy of the new biomimetic scheme is assessed in terms of adaptiveness and versatility. The performance study uses representative classes of internet traffic stream behaviour, service user's behaviour, demand intensity, multiple services co-hosting as well as differentiated hosting fee schedule. The biomimetic orchestration scheme is compared with the classical and the theoretical optimal orchestration techniques in terms of revenue stream. This study reveals that the new server ensemble orchestration approach is adaptive in a widely varying external internet environments. The study also highlights the versatility of the biomimetic approach over the classical technique. The self-tuning scheme improves on the original performance. The energy-aware scheme is able to conserve significant energy with minimal revenue performance degradation. The simulation results also indicate that the new scheme is competitive or better than classical and static methods.

Keywords: Nature-Inspired Computing
Social Insects
Server Allocation Algorithm
Biomimicry
Mathematics
Behavioural Biology
Biomimesis
Bio-Inspired Computing
Operation Research
Data Centre
Self-Organising Algorithms
Biomimetic
Advisor: McColl, W
Tovey, C
Social mechanisms of tax behaviour

The main goal of this thesis is to provide a sociologically informed analysis of tax avoidance and tax evasion in contemporary Mexico and Sweden, focusing particular attention on the explanatory role of social networks, social interactions, and positive feedback mechanisms.
Two major data sources are used: (1) A panel dataset that includes all persons, 16 years or older, who resided in Stockholm County during at least one of the years 1990 to 2003 (N=1,967,993). The dataset includes detailed information on the socio-demographic characteristics, kinship networks, and criminal offences of these individuals; (2) A random sample of 36,949 firms that appeared in the Mexican Federal Register of Taxpayers for the year 2002. The records of the Mexican Federal Administrative Fiscal Tribunal provided data on all types of tax claims appealed before them during the 2002-2008 period.
A variety of approaches and techniques are used such as agent-based simulation models, discrete time event history models, random effect logit models, and hierarchical linear models. These models are used to test different hypotheses related to the role of social networks, social interactions, and positive feedback mechanisms in explaining tax behaviour.
There are five major empirical findings. (1) Networks seem to matter for individuals' tax behaviour because exposure to tax crimes of family members appears to increase a person’s likelihood of committing a tax crime. (2) Positive feedback mechanisms appear relevant because if a person commits a tax crime, it seems to increase the likelihood that the person will commit more tax crimes in the future. (3) Positive feedback mechanisms are also important for explaining corporate tax behaviour because a firm that has engaged in legal tax avoidance in the past appears to be more likely to engage in tax avoidance in the future. (4) Network effects are important in the corporate world because exposure to the tax avoidance of other firms increase the propensity of a firm to engage in tax avoidance. (5) Substitution effects between tax evasion and tax avoidance are likely to exist because when tax evasion becomes more prevalent in a firm’s environment, their likelihood of engaging in legal tax avoidance is lowered.
The results underscore the importance of a sociological perspective on tax behaviour that takes into account social interactions and positive feedback mechanisms. In order to understand microscopic as well as macroscopic tax evasion patterns, the results presented in this thesis suggest that much more attention must be given to mechanisms through which taxation crimes breed more taxation crimes.

Keywords: taxpayer-compliance
Sweden
corporate-tax-avoidance
Mexico
social-mechanisms
social-networks
social-interactions
tax-crimes
tax-behaviour
evasion
Advisor: Biggs, M
Essays on the allocation of labour and capital in Indonesia

This dissertation comprises three essays on the allocation of labour and capital in a large developing country, Indonesia.
In the first essay, I examine the impact of the 1998 East Asian recession on child schooling outcomes in Indonesia. Using panel data on 7-15 year-olds, I exploit the heterogeneous impact of the recession across urban communities as measured by the variation in rice price increases, under the assumption that communities where rice prices increased the most were those where real wages declined the most. I find that for the youngest children (aged 7-12 years) there is a large negative impact of higher rice prices on school attendance and no effect on labour market participation. For older children (aged 13-15 years), schooling enrolment does not respond to rice prices but labour market participation declines sharply in the worst-hit communities. I find no evidence of adverse long-term consequences on human capital formation.
In the second essay, I test the hypothesis that there exists a significant earnings differential between similar workers in the formal and informal sectors. Using panel data on salaried and self-employed individuals, I find that after controlling for firm size and individual-specific heterogeneity, there is no formal sector earnings premium, except in the public sector. The results are robust to the presence of unpaid family workers, measurement error, and non-random attrition in the survey. This questions the commonly held belief that labour markets in developing countries are segmented because of legal institutions that protect high formal sector earnings.
In the third essay, I estimate the effect of a large exchange rate depreciation on the performance of importers. The ability to manage volatility in the cost of imported inputs is likely to depend on a firm's access to external sources of finance as well its ability to hedge against exchange rate movements. Using data from a census on Indonesian firms, I find that while domestic importers face lower value-added due to a rise in their costs of production, foreign-owned importers fare better: they are more likely to sustain higher value-added, hire more labour and use more materials than domestic owned firms. This suggests another channel through which FDI can add value to a firm in a developing country, particularly with the increasing importance of trade in intermediate goods.

Keywords: economics and education
microeconomics
development economics
labour economics
Advisor: Dercon, S
Rice, P
Finnegans wake and readership

The argument of this thesis is that Finnegans Wake is a peculiarly appropriate text for an investigation of the academic discipline of English, and that the issue of readership is the best way to approach the Wake. The thesis, which is organised into three main sections, shows that both Finnegans Wake and the discipline of English Studies are similarly engaged in problems of defining audiences. The opening section shows that the Wake has long been seen as a limit to literature, and as a defining text of literary study. Reception theory proves unable to cope with a study of historical audiences. Finnegans Wake was written over a period roughly concomitant with the rapid professionalisation of English studies and underwent a loss of audiences except for its critical reviewers. The extended third chapter sets out in some detail the growth of English studies, both in itself and more specifically as a context for the name of Joyce in the 1930s and beyond. This also includes analysis of the passage of the Wake in university syllabi. The second section considers post-structuralist claims that the Wake disrupts or subverts the space of the academy. It analyses a wide range of poststructuralist and other reactions to the Wake, and proceeds to a study of inscriptions of readership in the work of Derrida, and explores Derrida's idea of audiences for Joyce. The third section presents two readings of key elements of Finnegans Wake. Analysis of the letters, and of some of Joyce's sources, stresses the important role of the professor figures, which is indicative of the extent to which Joyce's last work was influenced by the professionalisation of literary study. Textual analysis proceeds with the Four, who function as an internal interpretive community. A brief conclusion sums up the argument of the thesis.
Failure analysis of pressure vessels with defects

A combined theoretical and experimental study of the criteria governing the failure analysis of pressure vessels with defects has been performed.
The fields of fracture mechanics (linear elastic and elastic-plastic behaviour), failure governed by large scale plastic deformation and energy balance methods are critically reviewed. All three approaches are shown to have relevance in the complete failure analysis of a structure with defects.
An experimental study of the failure mechanisms of precracked polycarbonate and maraging steel plates and model polycarbonate vessels is presented. Room temperature, static loading tests are performed on 85andnbsp;mm wide, 5andnbsp;mm thick compact specimens of polycarbonate (0.013 andle; aandfrasl;W andle; 0.810). For comparison, 51andnbsp;mm wide maraging steel compact specimens are monotonically loaded at room temperature. The influence of through-thickness constraint on the fracture toughness and slow crack growth characteristics of the steel is investigated using plates of varying thickness (3.1andnbsp;mmandndash;25.4andnbsp;mm) and initial crack length (0.386 andle; aandfrasl;W andle; 0.766 for 3.1andnbsp;mm thick sheet); various ancillary studies (scanning electron microscopy, surface deformation studies) complement the results.
The crack growth behaviour of longitudinal through (0.704 andle; c / andradic;DT/2 andle; 1.434) and deep part-through (dandfrasl;T = 0.700 and 0.878) cracks in 50.8andnbsp;mm and 102andnbsp;mm diameter (5andnbsp;mm and 6andnbsp;mm wall thickness) polycarbonate cylinders is also studied.
Bowling and Townley's two-criteria approach to failure i.e. LEFM on the one hand and limit analysis on the other, is shown to provide a useful method for assessing the relative importance of crack initiation, in the presence of limited crack tip plasticity and general yield as failure criteria for a given sized defect. Thus, for crack tip plasticity fully contained by an outer elastic field i.e. not general yield, the LEFM parameter, KIc (with the possibility of a plasticity correction factor for thin sheet) can be used to predict crack initiation. For the low strain-hardening maraging steel, Irwin's plane strain plasticity correction, 1andfrasl;6andpi; (KIc/andsigma;y)2 is shown to be applicable to sheet thicknesses comparable to 1andfrasl;andpi; (KIc/andsigma;y)2 i.e. twice Irwin's plane stress plastic zone radius.

Advisor: Ruiz, C
Modelling rainforests

In this dissertation, we develop a competition-colonisation model to describe the dynamics of interactions between tropical rainforest tree species. There is a great deal of interest in modelling rainforest diversity. Understanding the natural processes that maintain diversity is essential so that sustainable management systems can attempt to replicate important processes. We find, through numerical investigation and analysis, that with constant colonisation rates, ci
, we cannot predict multiple species coexistence. The inclusion of decaying colonisation rates, describing the seedling population decay over time, and random mass fruiting events allows coexistence of species, but using unrealistic parameter values. Finally we investigate a mathematical model without any competition between species and find that, using realistic parameter values, our results qualitatively mimic observations of rainforest dynamics. The results of the no competition model support Hubbell's null hypothesis [17].