VictorJuiz/thesis huggingface dataset:
Mechanism Design for Multi-dimensional Facility Location Problems: A Computational and Informational Perspective
Keywords: Facility location problem
Mechanism desgin
Single-peaked preferences
Social choice

Mechanism design deals with the design of protocols to elicit individual preferences while achieving some social objective (e.g., maximizing social welfare). An important property of mechanisms is strategy-proofness, which requires that no agent can gain (or induce a more preferred outcome) by misreporting her preferences to the mechanism. Previous results have shown that when monetary transfer (e.g., in the form of payments) is allowed between agents and the mechanism, the famous VCG mechanism is both strategy-proof and efficient (for social welfare maximization). Despite these positive results, there are still many settings where monetary transfer is difficult to implement, or even prohibited. For instance, political policies are generally determined without payment; monetary compensation between parties that are involved in organ donation is illegal in most countries, etc. It is natural to ask that whether it is possible to design strategy-proof mechanisms when monetary transfer is not allowed. This line of research, referred to as ``mechanism design without payment", has received much attention from people in economics, political science, and more recently, computer science. In this thesis, we study a classical embodiment of mechanism design without money called the facility location problem: suppose the municipal government plans to build several homogeneous facilities according to the reported preferred locations of the residents. Each resident would prefer one of the facilities built near his home/office (or ideal location), and the facilities should be built to minimize the social cost (i.e., sum of costs over all agents) or other social objectives. We study the facility location from three perspectives: mechanism design, single-peaked preferences and preference elicitation. We first propose a family of strategy-proof mechanisms for multi-dimensional, multi-facility location problem, called quantile mechanisms, by extending the classical generalized median mechanisms. We also show that the quantile mechanism are approximately group strategy-proof for constrained/unconstrained facility location problems, and study the computational complexity of finding an optimal group manipulation. Next, we study the common assumption of single-peakedness used in classical mechanism design for facility location problems, and show that agent preferences are far from being single-peaked in one-dimension, but approximately single-peaked in two-dimensions. Finally, we study preference elicitation in facility location problems (along with the second price auction), and propose a framework for analyzing the tradeoff between efficiency and privacy.
Non-governmental Organization's (NGOs) Impact on Health Care Services in Rural Honduras: Evaluating a Short-Term Medical Mission (STMM) Utilizing a Case Study Approach
Keywords: Case Study Design
Evaluation
Global Health
Honduras
Primary Health Care
Short-Term Medical Missions

Non-Governmental Organization’s (NGOs) Impact on Health Services in Rural Honduras: Evaluating a Short-Term Medical Mission (STMM) Utilizing a Case Study Approach Canada is a leading, international country that engages in Non-Governmental Organization (NGO)-led STMMs to low and middle-income countries for the provision of health care, education or structural development. Honduras, a chief destination country, is one of the poorest, most politically unstable in Central America. Health expenditure is among the lowest in the Americas, approximately 30.1% of the population receives no health care, and there is marked exclusion of ethnic and rural minorities. In Honduras, there is a paucity of evidence on the expectations, coordination and outcomes of STMMs. Guided by World Health Organization’s Primary Health Care (PHC) framework, an exploratory, type 2, single case study with a multiple embedded units design was used to address two research questions relating to the processes and outcomes of STMM services, and how stakeholders assess services. Eight propositions supported the data collection and a 12-day STMM involving 7 rural villages in Gracias a Dios (client n = 1120) constituted the case over three time periods (pre, during, and 10-weeks post STMM). Other data sources were key stakeholders (regional health/host officials, Honduran and Canadian health care providers). A revised, adapted Harvard evaluation tool was the principal data collection instrument. According to a review of English publications, this is the first longitudinal assessment of STMM processes, outcomes and community perspectives. Community members provided rich details regarding factors that impact their health, such as their impoverished situation and environmental challenges and risks (water, sanitation, food scarcity, poverty, and limited transportation). Diagnoses and treatments were consistent with the evidence of predominant health issues and medications provided in similar regions. Due to limited resources and/or unavailability of services STMM, clients had no opportunity to follow up on referrals. The results suggest that the existing STMM model is limited to adequately meet the needs of the people living in a rural and remote region of Honduras where poverty is extreme. The discussion situates the findings within the context of a country where, despite individuals’ constitutional right for health, political instability and multiple, intersectoral complexities challenge such right and reveal that STMM’s contributions are valued but fragmented with largely unknown outcomes. Recommendations for STMM quality and accountability, policy, education, and future research are presented.
Towards Offering Performance Guarantees in Software-Defined Networks
Keywords: Fabric
HyperFlow
Network Function Virtualization
NOX
Performance Isolation
Software-Defined Networking

Software-Defined Networking (SDN) promises to bring the long-sought flexibility to networks by decoupling packet handling (data plane) and network control (control plane). SDN's logically central control and poor performance of early SDN controller prototypes raised concerns about its performance and scalability. Moreover, the simple hardware-based datapath that legacy SDN assumed is a major obstacle to implement complex policies without significant performance penalty. In this thesis, I show that SDN could offer performance guarantees without sacrificing flexibility. First, I present NOX-MT and HyperFlow that are controller designs that demonstrate the performance and scalability of that logically central control could offer. NOX-MT improves NOX's (the legacy SDN controller) performance by an order of magnitude and can handle $1.6M$ events per second with $8$ cores. HyperFlow transparently captures and replays state altering events to construct an eventually consistent global view across controllers. HyperFlow's prototype can synchronize 1500 events across the network in a single RTT. Second, I propose an alternative design that embraces the notion of edge-core distinction and software at the edge to free the network core from implementing complex policies and introduce the much-needed flexibility in data plane at the edge. Software datapaths are increasingly common in today's networks but they introduce a new challenge: Performance guarantees that a software datapath provides in isolation no longer holds when it is consolidated with other software datapaths. I show that performance degradation under consolidation can be directly controlled (with less than $3\%$ error) by isolating accesses to the last-level processor cache. Finally, I present a formulation of the service-level agreement enforcement problem the solution to which is a placement of software datapaths and their cache allocations that guarantees performance objectives.
miRNA Analysis by Next-generation Sequencing and its Prognostic Importance in Non-small Cell Lung Cancer
Keywords: Lung Cancer
miRNA
Next-generation sequencing

Lung cancer is the leading cause of cancer death worldwide, with an estimated 1.8 million new cases diagnosed each year. Non-small cell lung cancer (NSCLC) is the predominant histological type, accounting for approximately 85% of all lung cancers. Despite significant advances in smoking cessation, early detection and genetic understanding of the disease, the 5-year overall survival has remained at ~15% over the past few decades. Post-surgical chemotherapy has been shown to improve the survival of some early-stage NSCLC patients, but the overall benefit is modest. To optimize the toxicity/benefit ratio, better diagnostic tools are needed to identify low-risk individuals who can be spared from unnecessary intervention, while avoiding undertreating high-risk patients. Over the past decade, a multitude of prognostic gene signatures has been published, however, none are currently used in the clinical setting to guide therapeutic decision-making. It is hypothesized that the integration of multidimensional high-throughput molecular data may better capture the molecular heterogeneity of lung cancer patients, resulting in more robust biomarkers for patient classification. To aid in the prediction of patient outcome using multidimensional molecular data, I have worked on different stages of the process of biomarker development with respect to microRNAs (miRNA) and their potential added prognostic value to gene signatures. First, I conducted a comprehensive comparison of miRNA profiling technologies, including next-generation sequencing, a microarray platform and the NanoString nCounter System. Next, data preprocessing methods were evaluated to develop a standardized pipeline for the preprocessing of small RNA-seq data, with the end-goal of retrieving miRNA count abundance profiles. Finally, miRNA profiling was performed on tumour specimen resected from early-stage NSCLC patients and combined with gene expression profiling data for the development of an integrated miRNA-mRNA risk classifier for predicting prognosis. The knowledge gained from these studies provides technical insights for the analysis of miRNAs and biological insights for the development of more robust prognostic classifiers.
Planetary Dynamos: Magnetic Constraints on the Interior Structure and Evolution of a Planet
Keywords: Computational Fluid Dynamics
Dynamos
Planetary Evolution
Planetary Interiors
Planetary Magnetic Fields

Planetary magnetism is a phenomenon that not only protects humanity from the destructive forces of nature, but also provides us with a natural probe into our planet's deep interior. In this dissertation, I will explore some of the insights concerning planetary interiors that can be gained by combining the techniques of interior structure modelling with constraints provided by planetary dynamo theory. Applications to the dynamical history of the Moon, the interior evolution of Jovian planets, and predicted magnetic fields of planets in our solar system and beyond are considered under this framework. The inferred intensity and longevity of the lunar dynamo from paleomagnetic studies has led to the proposition of mechanical stirring, caused by differential rotation of the inner core and the mantle relative to the fluid outer core, as an energy source alternative to convection. Using fully three-dimensional magnetohydrodynamics (MHD) modelling techniques, I simulated the purported mechanism, and found it to reproduce not only the strength and longevity of the inferred lunar dynamo, but also its precipitous decline later in its history. For the Jovian planets, due to the lack of constraints, there are a wide range of acceptable interior models in the literature. By combining 1-D interior modelling techniques with constraints imposed by theories of the planet's dynamo, I was able to construct improved models of these planets' interior structure. The discrepancy between the pictures of the Neptunian interior suggested by dynamo models and by thermal evolution models motivated improvements on our current theories about multipolar magnetic field generation. Therefore, I determined some predictive scaling laws for the magnetic field morphologies of planets (and exoplanets) using parameter studies of interior structure and dynamo models. These results will aid in our understandings of the link between interior properties and observed magnetic field characteristics for planets in our solar system and beyond. The following thesis documents the valuable insights gained by combining interior structure models and theories of planetary evolution with the study of planetary dynamos.
Social Impairment of Adolescents with Attention-deficit/Hyperactivity Disorder
Keywords: Adolescents
Attention-Deficit/Hyperactivity Disorder
Bullying
Social Cognition
Social Impairment
Social Skills

The goal of this dissertation was to enhance our understanding of the social impairment of adolescents with Attention-Deficit/Hyperactivity Disorder (ADHD). It examined several aspects of their social functioning including bullying, social skills, and social perspective taking (SPT) and how SPT is related to social skills. In Study 1, I sought to determine whether adolescents with and without ADHD differ in rates of bullying and victimization, and to describe the nature of their experiences. In Study 2, I examined whether adolescents with and without ADHD differ in their levels of SPT and social skills and to examine the association between these skills. The sample comprised 112 13- to 18-year-old adolescents: 59 (39 male, 20 female) with ADHD and 53 (25 male, 28 female) without ADHD. Adolescents, as well as their parents and teachers, completed measures assessing 1) adolescents’ inattention, hyperactivity-impulsivity and oppositionality; 2) adolescents’ experiences of victimization by peers and bullying others and 3) adolescents’ SPT and social skills. Results indicated that, according to parent report, adolescents with ADHD were more likely to be victimized by peers than adolescents without ADHD. However, the patterns of victimization they experienced were normative. In terms of bullying others, there were discrepancies between adolescent- and parent-report. Adolescents with ADHD demonstrated impairment in SPT and social skills. They had lower SPT skills, suggesting that they have difficulty considering multiple perspectives and coordinating their perspectives with others in social situations. Both adolescents with ADHD and their parents reported that these adolescents displayed deficits in social skills, though parents reported more severe deficits than adolescents did. The association between SPT and social skills was variable. For some self-reported social skills, SPT was a significant predictor over and above ADHD status, whereas for other domains, SPT moderated the relationship between ADHD status and self-reported social skills. SPT was not a significant predictor of parent-reported social skills over and above ADHD status for five domains, but it was for parent-reported responsibility skills. These findings are discussed within the context of the existing literature on the social functioning of adolescents with ADHD. Additionally, clinical implications and future directions are discussed.
Deconfinement and Duality of (super) Yang-Mills on Toroidially-compactified Spacetimes for all Gauge Groups
Keywords: confinement
duality
high energy physics
particle theory
phase transitions
theoretical physics

I study gauge theories for any gauge group G, in particular Yang-Mills (YM) theories including super Yang-Mills (SYM) and mass deformed super Yang-Mills (SYM*), on toroidially compactified spacetimes. Each compact direction introduces r=rank(G) massive scalar fields into the theory and results in an effective potential added to the Lagrangian of the theory. The mathematics of such potentials is interesting, however important applications begin with special simple cases. The first case studied here is finite temperature super Yang-Mills where a thermal circle of size 1/T is introduced and the temperature dependence of phases of the theory can be studied including the deconfinement phase transition. Further compactification on a spatial circle of size L is useful. For small such L we are in a regime where semiclassical calculations can be performed at weak coupling. The transition is found to be mediated by the competition between non-perturbative objects including monopole-instantons and 'exotic' topological molecules: neutral and magnetic bions composed of BPS and KK monopole constituents, with charges in the co-root lattice of the gauge group G, as well as electrically charged W-bosons (and wino superpartners in the case of SYM) with charges in the root lattice of G.\\ The second case is super Yang-Mills on circle compactified spacetimes, but with softly broken supersymmetry with a small mass m for the adjoint fermion. This is interesting as there is a conjectured continuity relating this theory, and its quantum deconfining phase transition at some critical mass for the gluino, to pure Yang-Mills with a thermal deconfinement transition at some critical temperature. Furthermore, on torus compactified spacetimes, I determine a duality for all G to a 2D Coulomb gas of bions of different charges of their monopole constituents, and W-bosons of both scalar and electric charges. Aharonov-Bohm interactions exist between magnetic bions and W-bosons. New scalar interactions of W-bosons and neutral bions exist which attract like charges, as opposed to the magnetic and electric charges where like charges repel. I then propose a dual lattice 'affine' XY-model with symmetry-breaking perturbations coupled to the scalar field, for SU(2), and show results of lattice studies to determine the nature of the deconfinement phase transition and propose generalizations for other groups.
Using Mathematical Models to Inform Syphilis Control Strategies in Men Who Have Sex with Men
Keywords: Communicable diseases
Epidemiology
Mathematical modeling
Screening
Sexually transmitted infections
Syphilis

Syphilis is resurgent in many high-income countries, disproportionately affecting urban men who have sex with men (MSM). Frequent screening of at-risk individuals remains the best available tool for syphilis control, but current public health efforts are not resulting in reduced disease burden. The aim of this thesis was to use mathematical modeling to understand the effect of different approaches to syphilis screening on epidemic dynamics and the health of MSM. An agent-based model of syphilis transmission in a core group of sexually active MSM was parameterized with data on the epidemiology of the current epidemic to evaluate plausible screening strategies that might be employed for epidemic control. Of the strategies evaluated, more frequent screening of at-risk MSM already accessing screening, rather than expanding outreach to provide screening to unscreened individuals, was found to be the most effective means of reducing syphilis incidence over a 10-year intervention period. A state-transition microsimulation model of syphilis natural history and medical care was developed to determine the cost-effectiveness of incorporating routine syphilis testing into the blood-work of MSM under care for HIV. When rates of syphilis acquisition were high, opt-out syphilis screening in HIV-infected MSM was projected to be a highly cost-effective intervention. A risk-structured deterministic compartmental mathematical model of syphilis transmission in MSM was used to examine the impact of sustained syphilis screening at varying levels of population coverage. Increasing screening in a population with initially low levels of coverage was shown to lead to increases in infection incidence. Although screening has the potential to control syphilis outbreaks, suboptimal screening coverage may result in the establishment of higher equilibrium infection incidence than that observed in the absence of the intervention, possibly contributing to outbreak persistence. The results of this research suggest that current control efforts are not expected to reduce syphilis incidence, with more effective screening programs required to reduce syphilis burden in MSM. The work presented in this thesis provides some insight into factors that may lead to screening programs that both improve the health of individuals and reduce the overall population burden, ultimately resulting in improved epidemic control.
Role of Notch Signaling and GATA-3 in Establishing T-lineage Commitment and Survival in Developing Thymocytes
Keywords: Epigenetic regulation of T cell development
GATA-3
Notch signaling
Thymocyte survival
T-lineage commitment

The adaptive immune response, including antigen-specific T cells, is crucial in resolving infections and protecting against tumourigenesis. However, the precise molecular signals needed for the development of these cells are still not clearly defined. The Notch signaling pathway is required to commit progenitors to the T-lineage and acts in concert with many transcription factors such as GATA-3 to fully induce this fate choice while inhibiting the B-cell lineage. Although both Notch and GATA-3 are indispensible for thymocyte development, their precise roles in directing these events remain to be elucidated. Examining such phenomena during ontogeny has been prohibited by genetic lethality caused by deletion of these genes early in development. Work presented in this Thesis provides means to circumvent this obstacle by establishing genetic systems, which allow to examine precise roles of Notch and GATA-3 in adult mice. Using RBPjind mice in which Notch responsiveness in all cells of hematopoietic lineage can be controlled with a Teton-inducible system, we demonstrate that Notch is absolutely required for generation of αβ and γδ thymocytes as well as marginal zone B-cells, while inhibiting B-lineage fate from bone marrow-derived progenitors. Similarly, conditional deletions of GATA-3 establish a profound need for this transcription factor in T-lineage specification for inducing expression of Bcl11b and directing early thymocyte proliferation and survival through repression of cell cycle-dependent kinase inhibitor 2b. Unlike Notch, GATA-3 was not required to inhibit B-lineage development but was crucial in preventing myeloid lineage outcome. These findings characterize a novel role for GATA-3 during T-lymphopoiesis and cement Notch signaling as a key lineage-commitment factor.