VictorJuiz/thesis huggingface dataset:
Performance analysis of neural networks applied to robot trajectory following systems

The advantage of neural network controllers to address robot trajectory tracking errors due to dynamic parameter uncertainties has been widely recognized. Despite many publications in the field of neural networks applied to repetitive robotic task execution, the lack of quantitative performance analysis impedes the application of neural networks in industry. The objective of this thesis is to formulate a systematic approach to analyze the mathematical relation between the performance and parameters of the neural network control robot system, i.e., the sensitivity of the system performance to parameters. This provides a better understanding how the neural network controller performs after the neural network is trained, a condition in which robot systems typically operate. First, the complete dynamic system is treated as a two-time-scale dynamics system, based on the perturbation theory. The learning rate is considered as a small parameter, the robot and neural network dynamics are regarded as fast and slow dynamic systems respectively. Then, the solution bound approach is employed to bound the norm of the system solutions. Finally, the influence of the system parameters, such as the robot payload and link mass etc., on the system performance, measured by the system error norm, is investigated using sensitivity analysis. Experimental results obtained with an industrial robot demonstrate the validity of the proposed approach. Above all, the quantification of the performance issue provides further justification for the commercialization of neural networks to robot systems. The future impact of this thesis is that it gives the basis to formulate an approach for synthesis of neural network control systems with guaranteed performance.
Chemical erosion of graphite due to simultaneous H§+ and O§+ irradiation

Graphite is one of the prime candidates for first-wall use in fusion devices. Its main advantages are its low Z and excellent thermomechanical properties, while its drawbacks are plasma-induced erosion and hydrogen retention. In addition to normal physical sputtering, graphite shows regimes of enhanced erosion at elevated temperatures. Exposure to hydrogen--the fusion fuel--in the temperature range 300-1000K leads to the formation of volatile hydrocarbons. Furthermore, since oxygen is often one of the main intrinsic impurities in the plasma of current fusion devices with carbon walls, the reaction of oxygen-containing ions with carbon materials also plays an important role in the complex process of plasma wall interaction. This thesis investigates the synergistic effect of H+ and O+ irradiation of graphite. Experiments of simultaneous O+ and H+ irradiation on graphite showed that water is formed as the main synergistic product, along with reductions in the CO/O+, CO2/O+ and CH4/H+ yields. Similar to CH4 yields, water yields (H2O/O+) are temperature dependent with maximum yield occurring at ~800K. Beam range separation experiments of O+ and H+ irradiations indicated that water is produced at the end of the O+ ion range. Furthermore, water formation was shown to be dependent on the mobile hydrogen concentration on internal surfaces, and independent of ion range separation. Reduction of CO and CO2 yields was found to depend on the reduction of oxygen supply due to water formation. CH4 yield reduction was found to be dependent on the incident oxygen, and the "methane break-up" mechanism was postulated and confirmed by Ne+-H+ [right arrow] C experiments. Experiments of simultaneous O+ and H+ irradiation on boron-doped graphite showed that the methane yield reduction due to break-up may be more than compensated for by the methane yield due to the combined presence of oxygen and boron. The reduction of methane yields from the H+ [right arrow] C/B reaction due to boron can also be partially nullified by the incident oxygen. Furthermore, O+-H + [right arrow] C/B irradiations showed that water formation was reduced when compared to O+-H+ [right arrow] C irradiations. These observations provided additional details in the CH4 and H 2O formation mechanisms. Finally, a semi-empirical mathematical model was formulated based on the emerging mechanisms.
A configurable framework for the provision of quality of service in third generation wireless systems

Third-generation wireless systems aim to enable multimedia-capable mobile communications. In this thesis, we present a framework to address four objectives central to that aim: QoS provision, adaptation to resource availability, application awareness, and programmability. A design was developed that integrates an adaptation controller to oversee adaptation in the channel access protocol, scheduling, and resource management, a QoS negotiation API to allow the application to specify its needs, and a module manager to enable the dynamic programming of key parameters. A proof of concept implementation was used to validate the interactions within the modules of the framework and with the upper and lower interface APIs. The contributions of this thesis are: (1) The integration of adaptation schemes at the data link and physical layer. (2) Programmability at two different levels: at the application-level through the QoS negotiation API and on a framework-wide basis through the Module Enhancement APIs. (3) A lower layer independent interface that allows the framework to collect channel state and dynamically update channel access protocol parameters.
Establishing the practical frontier in data envelopment analysis

Data Envelopment Analysis (DEA) assigns a score to each production unit (DMU) considered in the analysis. Such score indicates whether the unit is efficient or not. For inefficient units, it also identifies a hypothetical unit as the target and thus suggests improvements to their efficiency. However, for efficient units no further improvement can be indicated based on a DEA analysis. Nevertheless, it is important for management to indicate targets for their efficient units if the organization is to improve as a whole. If the inputs and outputs of efficient units can be varied within a specified range, then it is possible to find other combinations of inputs and outputs from which new, "artificial", DMUs can be created. These DMUs are constrained to be more efficient than the DEA efficient unit from which they were created. This thesis presents a linear programming model and a methodology for improving the efficiency of empirically efficient units by defining a new "Practical Frontier" and utilizing management input. This new frontier allows the analyst to identify adjusted efficiency scores for DMUs which were on the frontier when only real DMUs were considered. The new frontier, formed mostly from the new, artificial DMUs, thus ranks the efficient units which will now have scores less than 1.0. Available bank branch data was used to illustrate the applicability of this theoretical development.
The teaching of elementary Italian as a second language in Canadian universities, methodologies, curricula, and future considerations

Foreign language departments in Canadian universities are currently confronting new challenges that reflect distinctive exigencies in educational reform. These convey the following concerns on which these departments must immediately focus: (a) anticipated enrollment figures (as a result of expanding population and the "double cohort"), and (b) the changing student body (i.e., non-traditional L2 students) that will enroll in the course offerings of these language departments. As Italian is a microcosm of foreign language pedagogy in Canada (it truly is a reflection of the richness in research and practice of second language teaching and learning theories), Italian departments will harness these issues and interpret them positively by continuing to enhance research, materials production and curriculum design. These three fundamentals in second/foreign language pedagogy have been cultivated by a number of Italian pedagogues in Canada with great success. However, there has never been a comprehensive study to examine the national perspective of Italian as a foreign language. Therefore, the purpose of the study is to put forth the following three questions: (1) what are the current directions of research, and what influenced this research? (2) do the Italian language programs implemented in university curricula evidence the theoretical and practical research conducted by Canadian pedagogues? and (3) what do these programs indicate about the teaching of Italian in Canadian universities? As a response to these queries, this study first observes the current Canadian research in Italian L2 pedagogy, then provides a comparison of the elementary Italian programs adopted by the various universities, and concludes with implications and suggestions derived from research and curricula. As a final thought, a pedagogical cycle of elementary L2 Italian in Canadian universities is advanced to promote a more fully integrated and active investigation by all participants of this hypothesis. Data was collected from all Italianists whose focus in research is specifically language teaching at the beginner's level via publications and personal communications, while facts regarding program and syllabus design were collected via surveys distributed to the twenty-two universities that offer an introductory level Italian courses. As well, some universities were personally visited to experience both research and curriculum in action.
Util[i]zation and outcomes of interventional procedures for peripheral occlusive arterial disease in Ontario, a population-based study

This thesis describes the utilization and outcomes of interventional procedures for peripheral occlusive arterial disease in Ontario for fiscal years 1991 to 1998, using Ontario's administrative databases. The age and sex adjusted rate of arterial bypass surgery (ABS) fell significantly (p = 0.0002), whereas the rate of angioplasty increased significantly (p = 0.0005). However, the combined rate for revascularization procedures (ABS and angioplasty) was stable over the same time. The 5-year cumulative survival and major amputation-free survival rates for patients who underwent ABS were 61.5% and 83.4%, respectively and for patients who underwent angioplasty were 69% and 92.2%, respectively. These trends suggest a 'substitution effect' of angioplasty for bypass surgery, which in turn may reflect a change in the practice pattern of vascular surgeons in Ontario. Long-term survival and amputation-free survival rates may be used as a measure of the population-based effectiveness of revascularization procedures.
Combined Queue-Rate Active Queue Management for Internet congestion control

The 'Combined Queue-Rate Active Queue Management' (' QR-AQM') algorithm randomly drops the arriving packets, before the buffer overflows, to effectively control the: (1) 'Actual Queue Size' below a 'Desired Optimum Queue Size' (' Qopt') to limit queueing delay and avoid buffer overflows; (2) 'Buffer's Average Traffic Arrival Rate' in the vicinity of the 'Outgoing Link Capacity' to enable the control of congestion and queue size. QR-AQM combines the 'Actual Queue Size' and queue's 'Average Traffic Arrival Rate', in computing the ' Packet Drop Probability' upon each packet's arrival, by comparing the 'Expected' and 'Desired'/'Allowed ' changes in the queue level over a tunable 'Control Time Constant ' ('Tm') period, to achieve a better performance compared to schemes that use only the 'Average Queue Size' such as ' Random Early Detection' ('RED'). The performance comparisons of 'Linear' and 'Quadratic' QR-AQM to RED reveal that QR-AQM achieves its intended goals with a superior performance.
Novel polymer spheres and nanocomposites from the collapse of polyacrylic acid

Polyelectrolytes in very dilute solution exist as single chains. These single chains undergo a change in size from an expanded coil to a collapsed globular state upon addition of salt. The effects of NaCl, CUSo4 and AgNO3 on the collapse transition of polyacrylic acid were investigated. Gamma irradiation was used to permanently form the collapsed coils and reduce the metal ions. Novel particles in the form of polymer spheres and polymer-metal nanocomposites were observed and characterized.
Self-selection, labour markets and capital markets

Self-selection is a market allocation mechanism that is pervasive. Workers sort into jobs, firms sort into product and factor markets. My thesis analyses what effects self-selection mechanisms have on microeconomic phenomena such as the trade pattern and earnings inequality, and on macroeconomic phenomena such as the exchange rate and the capital account. The current work horse trade models are based on relatively simplistic labour market assumptions. In my first essay, I propose a model which instead incorporates a rich labour market model of worker sorting, the Roy (1951) model. This model unites the long-run production and trade predictions of the Heckscher-Ohlin model with the short-run political economy predictions of the specific factors model. In addition, it shows how even North-North trade can be based on endowments, being driven by differences in endowments inequality. In my second essay, I test this model empirically. I focus on the determinants of within-industry earnings inequality during the 1980s and 1990s using data from the CPS and the Bartelsmann-Becker-Gray database on productivity. The results overwhelmingly confirm the importance of skill-biased technological change in the rise in within-industry inequality during the sample period. In my third essay, I turn to the macroeconomic effects of firms self-selecting into export markets and into the international capital market. Only the most productive firms are able to export into foreign product markets and only the most productive among these exporters are able to borrow on the international capital market. In such a setting, capital account liberalisation has not only the standard effects on macroeconomic variables such as the exchange rate, but also on microeconomic variables such as aggregate firm productivity, firm exit and entry. The predictions generally match the developments in developing countries, most notably in Chile in the late 1970s and early 1980s. The analysis raises a note of caution: since capital account liberalisations have usually taken place concurrently with trade liberalisations, studies which correlate firm productivity with trade liberalisation have to be interpreted carefully.
Rethinking Jewish vitality, exploring sources of significance, affection and change in traditional Jewish ritual observance

Jewish survival in the Diaspora has always been complicated by the challenge to 'successfully' integrate into a host culture and yet remain distinctive. Some scholars see increases in North American Jews' generation status (distance from the immigrant experience) and success as an indicator and/or determinant of perceived losses to ethnic attachment. Others emphasize the additive dimension and significance of creative reconstructions of ethnic modalities into alternate bases of ethnic commitment. Deep disagreements over style and substance keep the Jewish vitality (continuity) debate at a stalemate. While ethnicity researchers are increasingly aware of the misspecification biases inherent in our current crop of assumptions, definitions and measures, they have been slow to revise their tools. To this end, over a period of thirty months, 100 in-depth, life history oriented interviews were conducted exploring the nature of Jewish identities, specifically the vitality of traditional Jewish ritual observances (TJRO), articulated by non-immigrant members, typically parents and offspring, of Toronto-based non-Orthodox, Jewish endogamous and intermarried households. Variation was unearthed in the priorities deemed significant to ones TJRO (personal, familial, social, congregational-communal, ancestral-historical or universal-mystical) and the emotional orientations (active or passive) that accompany these expressions. Importantly, performing many TJRO was not necessarily indicative of vitality in this area and those performing little TJRO were sometimes more committed to the few ritual observances they chose to maintain. The long interview format provided ample time to explore the dynamics of people's Jewish journeys. Various factors emerged and/or were assessed as agents of change and (dis)affection. Most notably, it was discovered that generation status was not a reliable predictor of Jewish vitality, it is operationally and conceptually problematic and obscures the important effects of other potentially interacting factors like differential immigrant starting points, period, and intrafamilial processes. In addition, charges of ethnic losses owing to intermarriage were found oversimplified and misdirected in light of 5 mediating variables. Other factors were identified, implications for further research noted and policy directives suggested. It was concluded that greater awareness and respect for Jewish plurality and a democratization of legitimate claims to Jewish authenticity could function to encourage and sustain ethnic attachment.
Validation of two standard risk assessments (RRASOR, 1997; STATIC-99, 1999) on a sample of adult males who are developmentally disabled with significant cognitive deficits

Problematic sexual behaviours in men with developmental disabilities often severely stigmatize, restrict, and limit the success of these individuals in our communities. Two actuarial risk assessments, the Rapid Risk Assessment of Sex Offender Recidivism (RRASOR) and the STATIC-99, developed for men with average intelligence, were applied to a population of men with significant cognitive deficits ('N' = 76). Analyses revealed that many factors that predict sexual reoffence in normative samples also predict reoffence in this sample. The 4 item RRASOR, outpredicted the 11 item STATIC-99. This may indicate a wider latitude of application to more diverse populations for the more generalizable RRASOR. Actuarial risk assessment can be used to better rationalize treatment and supervision resources thereby improving quality of treatment, community access and community safety. Future research should increase sample size and focus on the prospective investigation of dynamic predictors in samples of individuals with developmental disabilities.
Thermo-oxidation of carbon-containing materials in fusion reactors

The thermo-oxidation of codeposited layers on tiles removed from the upper divertor and midplane of the DIII-D tokamak in San Diego has been studied to determine the rate of D removal from the codeposit. Results of these studies show that the deuterium can be removed at a rate of up to 2 * 10-9 D/O2, with the rate decreasing significantly after the first few hours of O2 exposure. A study of impurities, in particular tungsten, on the oxidation of laboratory-produced plasma-deposited films and of graphite was performed to determine if catalytic activity could explain the range of oxidation results for tokamak produced films; little to no catalytic oxidation was observed. Carbon oxidation at low temperatures was also investigated to determine if thermo-oxidation in fusion reactors will erode the graphite walls. The upper limit on graphite erosion at 623K was <4 * 10-10 C/O2, several orders of magnitude smaller than the erosion of some codeposits.
Self/disciplining/body, a genealogy of obsessive-compulsive disorder

In this thesis, I posit and elucidate a relationship between processes of cultural knowledge production and the so-called psychiatric syndrome, obsessive-compulsive disorder (OCD). Using a primarily Foucauldian-derived framework, I draw from the work of major writers in the sociology of the body to produce a reading of Western culture through the embodiment of the disorder. I argue that many of the symptoms and characteristic experiences of OCD can be reconceptualized as expressions of, and engagements with, positively valued cultural beliefs, discourses and practices. In particular, my analysis centres upon discourses and processes of the self, body dualism and risk, and the way in which these are manifested in social bodies and spaces. In so doing, I call attention to the arbitrary distinctions between 'normal' and 'abnormal' psychology and behaviour, and between mentally 'ordered' and 'disordered' persons.
Futile cycling of estrone sulfate and estrone in liver

Futile cycling of estrone sulfate (E1S) and estrone (E1) is a pharmacologically important biocycle that regulates endogenous estrogens. In order to understand the influence of the futile cycling on E 1S and E1 hepatic clearances, vascular and tissue binding, zonal transport and metabolism, and excretion were investigated 'in-vitro ' and the variables were integrated stepwise to intact hepatocytes and then to perfused rat liver preparations. 'In-vitro' studies identified that E1S and E1 were highly bound to bovine serum albumin and tissues. In addition, E1 was bound and metabolized by erythrocytes. In zonal hepatocytes, acinar homogeneity was found for the transport of E1S and E1 and the desulfation of E 1S; these processes occur more rapidly than the sulfation of E 1, mediated predominantly by estrogen sulfotransferase in the cytosol of the perivenous over the periportal hepatocytes. When E1S was incubated with intact zonal hepatocytes, higher concentrations of E1 S and E1 were observed in periportal than in perivenous hepatocytes, and saturation was evident at the higher concentrations. When the in-vitro and hepatocyte data were fitted to a cellular model, the fitted results revealed that E1 sulfation was indeed the slowest step in futile cycling. The greater metabolism of E1 in PV hepatocytes, sulfation, glucuronidation, and hydroxylation led to lower E1 and E1 S levels in PV hepatocytes. Moreover, the nonlinear uptake, tissue binding, and vesicular accumulation of E1S resulted in different elimination half-lives for E1S and E1. Hence, hepatic clearances of E1S and E1 were investigated in the recirculating liver preparation with simultaneous delivery of tracer [3H]E 1S and [14C]E1. The hepatic clearances of [3H]E1S and [14C]E1 were high despite tight vascular binding. Low concentrations of [3H]E 1 were detected following the tracer [3H]E1S dose because [3H]E1 was highly partitioned into the microsomes. Thus, a distributed-in-space model that embodied vascular and tissue binding, transport, subcompartmentalization of the cytosol and endoplasmic reticulum, and zonal metabolism was used to interpret the perfusion results. The model described the perfusion data well. However, in the absence of drug partitioning into the endoplasmic reticulum, parallel elimination profiles for E1 and E1S, characteristic of compounds undergoing futile cycling, were observed in the simulation study.
Student response to equity issues in teacher education, pushing the boundaries of resistance and transformation

The purpose of this qualitative study was to explore how students responded to equity issues and required social foundational coursework in the context of a single teacher education program. Paying specific attention to programmatic context, student experiences and beliefs, student and faculty social location and instructor pedagogy, I generated data through semi-structured interviews with three instructors and twelve students involved in the program. I used a modified version of Giroux's (1983) theory of resistance to frame my interpretive analysis and generated hypotheses about factors linked to student transformation and resistance. After analysing the interviews reflexively, I found that the response of student resistance differed from that detailed in much of the teacher education literature and that in addition to resistance and transformation, many students responded with complacency and a few others with a dedication to advocacy work. I concluded with some implications for teacher educators and teacher education programs.