VictorJuiz/thesis huggingface dataset:
ECG in Biometric Recognition: Time Dependency and Application Challenges

As biometric recognition becomes increasingly popular, the fear of circumvention, obfuscation and replay attacks is a rising concern. Traditional biometric modalities such as the face, the fingerprint or the iris are vulnerable to such attacks, which defeats the purpose of biometric recognition, namely to employ physiological characteristics for secure identity recognition. This thesis advocates the use the electrocardiogram (ECG) signal for human identity recognition. The ECG is a vital signal of the human body, and as such, it naturally provides liveness detection, robustness to attacks, universality and permanence. In addition, ECG inherently satisfies uniqueness requirements, because the morphology of the signal is highly dependent on the particular anatomical and geometrical characteristics of the myocardium in the heart. However, the ECG is a continuous signal, and this presents a great challenge to biometric recognition. With this modality, instantaneous variability is expected even within recordings of the same individual due to a variety of factors, including recording noise, or physical and psychological activity. While the noise and heart rate variations due to physical exercise can be addressed with appropriate feature extraction, the effects of emotional activity on the ECG signal are more obscure. This thesis deals with this problem from an affective computing point of view. First, the psychological conditions that affect the ECG and endanger biometric accuracy are identified. Experimental setups that are targeted to provoke active and passive arousal as well as positive and negative valence are presented. The empirical mode decomposition (EMD) is used as the basis for the detection of emotional patterns, after adapting the algorithm to the particular needs of the ECG signal. Instantaneous frequency and oscillation features are used for state classification in various clustering setups. The result of this analysis is the designation of psychological states which affect the ECG signal to an extent that biometric matching may not be feasible. An updating methodology is proposed to address this problem, wherein the signal is monitored for instantaneous changes that require the design of a new template. Furthermore, this thesis presents the enhanced Autocorrelation- Linear Discriminant Analysis (AC/LDA) algorithm for feature extraction, which incorporates a signal quality assessment module based on the periodicity transform. Three deployment scenarios are considered namely a) small-scale recognition systems, b) large-scale recognition systems and c) recognition in distributed systems. The enhanced AC/LDA algorithm is adapted to each setting, and the advantages and disadvantages of each scenario are discussed. Overall, this thesis attempts to provide the necessary algorithmic and practical framework for the real-life deployment of the ECG signal in biometric recognition.

Keywords: electrocardiogram
biometrics
Advisor: Hatzinakos, Dimitrios
Embryoprotective Role of Endogenous Catalase

Oxidative stress and reactive oxygen species (ROS) such as hydrogen peroxide (H2O2), which is detoxified by catalase, are implicated in fetal death and birth defects, but embryonic levels of catalase are only about 5% of adult activity, and its protective role is unknown. Our approach involved the use of mice genetically modified to either: (1) express low levels of endogenous catalase (acatalasemic, aCat); or, (2) express human catalase resulting in elevated levels of embryonic catalase activity (hCat). Using these mouse models we investigated the protective importance of constitutive embryonic catalase against endogenous ROS and the ROS-initiating teratogen phenytoin in embryo culture and in vivo. We hypothesized that aCat mice would be more sensitive to endogenous embryonic and phenytoin-enhanced ROS production, while hCat embryos would be less sensitive. aCat and hCat embryos respectively exhibited reduced and enhanced catalase activity compared to wild-type (WT) controls, with conversely enhanced and reduced spontaneous and phenytoin-enhanced embryopathies and DNA oxidation. Among aCat embryos exposed to phenytoin, embryopathies increased with decreasing catalase activity, and were completely blocked by addition of exogenous catalase. The alterations in phenytoin embryopathies were not due to pharmacokinetic differences, as drug concentrations in maternal and fetal tissues were similar among all strains. However, phenytoin concentrations in fetal brain exceeded those in fetal liver or maternal tissues, which may explain the predominance of cognitive deficits over structural birth defects in children exposed in utero to phenytoin. Similarly in untreated aged mice (about 18 months), female aCat mice showed a substantial loss in motor coordination compared to WT controls in the rotarod test. Following in utero exposure to phenytoin, the effect of altered embryonic catalase activity on postnatal neurodevelopment was assessed by several pre- and post-weaning tests. Catalase deficiency (aCat), independent of drug treatment, reduced performance in surface righting, negative geotaxis tests and rotarod tests. Conversely, high catalase expression (hCat) enhanced performance in the surface righting, negative geotaxis, air righting and rotarod tests. Our results provide the first evidence that the quantitatively minor amounts of antioxidative enzymes like catalase in the embryo and fetus provide important protection against the molecular damage and adverse fetal effects caused by developmental and drug-enhanced oxidative stress. Accordingly, interindividual variation in embryonic/fetal activities of catalase, and possibly other antioxidative enzymes, likely constitute an important determinant of risk for adverse developmental outcomes.

Keywords: Catalase
embryonic development
Advisor: Wells, Peter G.
Managing Inventory, Transportation and Location in a Supply Chain

We consider three problems on inventory, transportation and location in a supply chain. In Chapter 2, we study Multilevel Rationing (MR) and Strict Priority (SP) stock allocation policies for a centralized single product multi-class M/G/1 make-to-stock queueing systems. To obtain the total cost of the system under these policies, we introduce a new method called “customer composition”. Using this method, we focus on the proportion of customers of each class out of the total number of customers in the queue since the number of customers in M/G/1 queues is invariant for any non-idling and non-anticipating policy. We consider a series of two-priority M/G/1 queues with an exceptional service time in each busy period to characterize the customer composition. We derive closed form expressions for the costs of SP and MR policies using these results. In Chapter 3, we consider a two-echelon inventory system with a congested centralized production facility and several Distribution Centers (DCs). We assume that the production and transportation times are stochastic that are generally distributed, and customers arrive to each DC according to an independent Poisson process. Inventory at DCs is managed using the one-for-one replenishment policy. We use the customer composition approach to characterize the total inventory carrying and backlog costs of the system under the FCFS, SP and MR allocation policies at the warehouse. For the special case of exponentially distributed production and transportation times, we use the unit-flow method and derive closed form expressions for the optimal cost and base-stock level of the DCs. We numerically demonstrate that prioritization using either the SP or the MR policy could be very beneficial in comparison with the FCFS policy. In Chapter 4, we study a two-echelon supply chain with a set of suppliers, a set of retailers and a set of capacitated cross-docks which are to be established. The demand of the retailers could be satisfied from the suppliers through the cross-docks. The objective is to determine the number and location of cross-docks, the assignment of retailers to suppliers so that the total cost of pipeline and retailers’ inventory, transportation, and facility location is minimized. We formulate the problem as a non-linear mixed integer programming and derive several structural results for special cases of the problem. To solve the general problem, we show that it can be written as a cutting stock problem and develop a column generation algorithm to solve it. We investigate the efficiency of the proposed algorithm numerically.

Keywords: Supply Chain Management
Queueing Analysis
Advisor: Berman, Oded
Early Verification of the Power Delivery Network in Integrated Circuits

The verification of power grids in modern integrated circuits must start early in the design process when adjustments can be most easily incorporated. We adopt an existing early verification framework. The framework is vectorless, i.e., it does not require input test patterns and does not rely on simulating the power grid subject to these patterns. In this framework, circuit uncertainty is captured via a set of current constraints that capture what may be known or specified from circuit behavior. Grid verification becomes a question of finding the worst-case grid behavior which, in turn, entails the solution of linear programs (LPs) whose size and number is proportional to the size of the grids. The thesis builds on this systematic framework for dealing with circuit uncertainty with the aim of improving efficiency and expanding the capabilities handled within. One contribution introduces an efficient method based on a sparse approximate inverse technique to greatly reduce the size of the required linear programs while ensuring a user-specified over-estimation margin on the exact solution. The application of the method is exhibited under both R and RC grid models. Another contribution first extends grid verification under RC grid models to also check for the worst-case branch currents. This would require as many LPs as there are branches. Then, it shows how to adapt the approximate inverse technique to speed up the branch current verification process. A third contribution proposes a novel approach to reduce the number of LPs in the voltage drop and branch current verification problems. This is achieved by examining dominance relations among node voltage drops and among branch currents. This allows us to replace a group of LPs by one conservative and tight LP. A fourth contribution proposes an efficient verification technique under RLC models. The proposed approach provides tight conservative bounds on the maximum and minimum worst-case voltage drops at every node on the grid.

Keywords: Verification
Power Grids
Advisor: Najm, Farid N.
Lanthanide-encoded Polysterene Microspheres for Mass Cytometry-based Bioassays

This thesis describes the synthesis and characterization of metal-encoded polystyrene microspheres with a narrow size distribution designed for mass cytometry-based immuno- and oligonucleotide-assays. These particles were prepared by multiple stage dispersion polymerization techniques using polyvinylpyrrolidone (PVP) as a steric stabilizer. As a cytometeric technique, mass cytometry necessitated metal-encoded microspheres to perform the same roles of fluorescent microspheres used in conventional flow cytometry. The first role of the microsphere was to be able to act as a platform (classifier microspheres) for bioassays. Secondly, the microspheres should be suitable for mass cytometry machine calibration as standards. To perform these roles, metal-encoded microspheres were required to have certain size, functionality and metal content criteria. Lanthanide elements were chosen as the metals for encoding the microspheres for their low natural abundance in biological systems and for their similar chemistry. My goal was to employ two-stage dispersion polymerization, of styrene in ethanol, to introduce the lanthanide salts along with excess acrylic acid in the second stage, one hour after the initiation. Acrylic acid deemed to serve as a ligand for the lanthanide ions, through its carbonyl group, so the lanthanide ions get incorporated into the microsphere while acrylic acid is copolymerizing with styrene. Using two-stage dispersion polymerization, I could synthesize lanthanide encoded microspheres with narrow size distribution and high lanthanide content. However the lanthanide content distributions were unexpectedly much broader than the size distribution obtained. In addition, I could not attach biomolecules to the surface of such particles. In an attempt to improve the characteristics of these microspheres, I employed modified versions of multiple stage dispersion polymerization and seeded emulsion polymerization to grow functional polymer shell on the surface of the particles prepared by dispersion polymerization. Moreover, I coated the lanthanide encoded microspheres with silica shell which enabled me to grow another layer of functional-silica. Consequently, I could use these particles as classifier microspheres for mass cytometry-based immunoassays as well as fluorescence-based oligonucleotide-assays.

Keywords: polymer microspheres
Lanthanides
Immunoassays
Dispersion polymerization
Biological assays
Metal encoding
ICP-MS
Mass cytometry
Advisor: Winnik, Mitchell A.
Early Age Mechanical Behavior and Stiffness Development of Cemented Paste Backfill with Sand

Rapid delivery of backfill to support underground openings attracted many mines to adopt paste backfilling methods. As a precaution to prevent liquefaction and to improve the mechanical performance of backfills, a small portion of a binder is added to the paste to form the cemented paste backfill (CPB). Recently, adding sand to mine tailings (MT) in CPB mixes has attracted attention since it enhances the flow and mechanical characteristics of the pastefill. This thesis investigates the effects of adding sand to CPB on the undrained mechanical behavior of the mixture (CPBS) under monotonic and cyclic loads. Liquefaction investigations took place at the earliest practically possible age. Beyond this age, the present research focused on characterizing the evolution of stiffness and obtaining the values of the stiffness parameters that could be useful for designing and modeling backfilling systems. The liquefaction investigation involved monotonic compression and extension triaxial tests. Neither flow nor temporary liquefaction was observed for all cemented and uncemented specimens under monotonic compression, while temporary liquefaction was observed for all specimens under monotonic extension. The addition of binder and sand to MT was found to slightly strengthen the pastefill in compression while weakening it in extension. Under cyclic loading, the addition of sand negatively impacted the cyclic resistance. However, binder was found to be more effective in the presence of sand. All specimens exhibited a cyclic mobility type of response. The evolution of effective stiffness parameters for two CPB-sand mixtures was monitored in a non-destructive triaxial test for five days. Self-desiccation was found to not be influential on the development of early age stiffness. Moreover, a framework is suggested to predict the undrained stiffness at degrees of saturation representative of the field. The credibility of the proposed test in providing stiffness parameters at representative strain levels of the field was verified.

Keywords: Cemented paste backfill
Liquefaction
Cyclic
Monotonic
Stiffness
Hydration
Advisor: Grabinsky, Murray
Bawden, William
Science-based Health Innovation in Sub-Saharan Africa

Policy making bodies are increasingly highlighting the important role innovation can play in African development─not only to spur economic growth but also to deliver locally relevant, affordable products and services to African populations. The health sector is one area where innovation is most needed; however, we know very little about the capacity of African countries to innovate in this area. At the same time, a range of conceptual questions have arisen in the academic literature as to the very definition of innovation in an African context, and specifically, the applicability of the National Innovation System (NIS) to African countries. Through detailed case study research of science-based health firms in South Africa, of the NIS health system of Ghana, and by comparing these data with data collected in Uganda and Tanzania, I shed light on these questions from an empirical perspective. I find that science-based health innovation is a complex field, and whilst institutions can help or hinder its viability, the current state of health innovation in SSA can be attributed primarily to individual entrepreneurs with strong networks, who are taking risks in a largely non-enabling environment. I find that, more important for innovation, is the ability to access global knowledge–through appropriate policies and strong partnerships–and the capacity to apply it locally. For this, tacit knowledge, or “learning-by-doing,”’ to respond to consumer demand and achieve regional product penetration, is vital. My results show that the traditional focus on knowledge - or science-heavy innovation - will simply not capture the true extent of health innovation in SSA countries. Furthermore, science-based health innovation is clearly not one thing, and it is, for example, important to understand how plant medicine innovation fit in. The aims, intentions, and impacts of African health research on the countries themselves are rather vague, which constrains innovation at all levels.

Keywords: Innovation
Science and Technology
Advisor: Singer, Peter A.
Health Technology Innovation by Indigenous Enterprises in China, India and Brazil

This thesis explores health technology innovation within indigenous enterprises in China, India, and Brazil. The main discussions are presented in five papers/manuscripts. The first is a case study of Brazil’s health biotechnology sector. It concludes that systemic tensions between the country’s public and private sectors may be detracting from its overall innovative success. The second paper gauges vaccine and medicinal innovation within enterprises in the stated countries by analyzing new technologies in their pipelines or on the market. It concludes that that a growing number of health enterprises in these countries are tackling more technologically challenging and costly innovations. The third paper explores how national institutions and industry globalization interact to shape commitments to new drug and vaccine innovations by enterprises in the three countries. It concludes that; a) the introduction of pharmaceutical product patent regimes has had a modest impact on entrepreneurial attempts to develop new technologies, b) key challenges that diminish patent incentives tend to be institutional in nature and, c) the increasingly globalized nature of health product innovation limits what countries can achieve independently. The fourth paper analyzes key issues and trends in health biotechnology firms’ transition to innovation in China, India, Brazil, and South Africa. It concludes that this transition often entails greater integration into the global system. The fifth paper ponders the implications for global health of the emerging market firms’ transition to innovation. It concludes that these enterprises have the potential to simultaneously address global health needs while exploiting global markets, provided support mechanisms are put in place to enable product development for the poorest market segments. This research suggests that to succeed in biopharmaceutical innovation, nations need to adjust scientifically, sectorally and globally all at the same time. Also, that national governments and the global health community need to enhance engagement of emerging market enterprises in related efforts.

Keywords: Biotechnology
Innovation
Pharmaceutical
Enterprises
Advisor: Singer, Peter A.
Sociolinguistic (Re)constructions of Diaspora portugueseness: Portuguese-Canadian Youth in Toronto

This dissertation demonstrates that notions of language and identity are not entirely about personal characteristics (what a person is born with, what is "in his blood"), nor are they entirely about agency (how a person chooses to present herself). Instead, they are largely about markets and about the multiple positionings of social actors within markets that are structured by ideologies of the nation state, immigration and the globalized new economy. This critical perspective challenges the normalized view that immigrant (diasporic) communities are simply natural social groupings or depoliticized transplantations of distinct ethnolinguistic units from their "homeland". They are, like language and identity, carefully constructed and managed social projects that are shaped by forces from within and from without. In Canada, the conditions for the institutionalization and (re)production of ethnolinguistic differences, which also make and mark class relations, are strengthened by the state’s multiculturalist policy. The Portuguese-Canadian community is one such ethnolinguistic market and the goal of this research is to examine which forms of portugueseness dominate the market, why and with what consequences for whom. Building from an ethnographic and critical sociolinguistic approach (Bourdieu 1977, Heller 2002), the qualitative data behind this research was produced through a two-year ethnography, participant observations and semi-structured interviews drawing primarily from six second-generation Portuguese-Canadians and members of their social networks. The findings suggest that the kind of portugueseness that dominates the Portuguese-Canadian market is one from Mainland Portugal; one that is folklorized, patriarchal, and that promotes (Mainland) Portuguese monolingualism and false cultural homogeneity. A consequence of this sociolinguistic structuration is a division between Azoreans and Mainlanders who make up two parts of the same Portuguese market; partners in conflict over the legitimacy and value of their linguistic and social capital. Furthermore, the inheritors of this market, the second and subsequent generations, navigate discursive spaces filled with contradictions that often marginalize them. Their experiences highlight strategic mobilizations of Portuguese language and identity, as well as the consequences of having delegitimized cultural and linguistic capital. In short, this dissertation highlights the productive tensions between structure and agency, between uniformity and variability, and between exclusion and inclusion.

Keywords: Sociolinguistics
Ethnography
Linguistic Anthropology
Identity
Multiculturalism
Globalization
Postnationalism
Advisor: Brousseau, Anne-Marie