Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.

Historically, credit market conditions have been shown to impact economic activity, at times severely. For instance, in the late 2000s, the United States experienced a financial crisis that seized domestic and foreign credit markets. The ensuing lack of access to credit brought about a steep decline in output and a sluggish recovery. Accordingly, policymakers commonly take steps to mitigate the effects of adverse credit market conditions and, at times, conduct unconventional monetary policy once traditional policy tools become ineffective. This dissertation is a collection of essays regarding monetary policy, the flow of credit, financial crises, and the macroeconomy. Specifically, I describe monetary policy’s impact on the allocation of credit in the U.S. and analyze the role of upstream and downstream credit conditions and financial crises on international trade in a global supply chain. The first chapter assesses the impact of monetary policy shocks on credit reallocation and evaluates the importance of theoretical transmission mechanisms. Compustat data covering 1974 through 2017 is used to compute quarterly measures of credit flows. I find that expansionary monetary policy is associated with positive long-term credit creation and credit reallocation. These impacts are larger for long-term credit and for credit of financially constrained firms and firms that are perceived as risky to the lender. This is predicted by the balance sheet channel of monetary policy and mechanisms that reduce lenders’ risk perceptions and increase the tendency to search for yield. Furthermore, I find that, on average, the largest increases in credit creation resulting from monetary expansion are to firms that exhibit relatively low investment efficiency. These estimation results suggest that expansionary monetary policy may have a negative impact on future economic growth. The second chapter evaluates the quantitative effects of unconventional monetary policy in the late 2000s and early 2010s. This was a period when the traditional monetary policy tool (the federal funds rate) was constrained by the zero lower bound. We compute credit flow measures using Compustat data, and we employ a factor augmented vector autoregression to analyze unconventional monetary policy’s impact on the allocation of credit during the zero lower bound period. By employing policy counterfactuals, we find that unconventional monetary policy has a positive and simultaneous impact on credit creation and credit destruction and these impacts are larger in long-term credit markets. Applying this technique to analyze the flows of financially constrained and non-financially constrained borrowing firms, we find that unconventional monetary policy operates through the easing of collateral constraints because these effects are larger for small firms or those with high default probabilities. During the zero lower bound period, we also find that unconventional monetary policy brings about increases in credit creation for firms of relatively high investment efficiency. The third chapter pertains to the global trade collapse of the late 2000s. This collapse was due, in part, to strained credit markets and the vulnerability of exporters to adverse credit market conditions. The chapter evaluates the impact of upstream and downstream credit conditions and the differential effects of financial crises on bilateral trade. I find that upstream and downstream sectors’ needs for external financing is negatively associated with trade flows when the exporting or importing country’s cost of credit is high. However, I find that this effect is dampened for downstream sectors. I also find that downstream sectors’ value of collateral is positively associated with trade when the cost of credit is high in the importing country. High downstream trade credit dependence coupled with high costs of credit in the importing country also cause declines in imports. There are amplifying effects of credit costs for sectors that are highly dependent on external financing when the importing or exporting country is in financial crisis. Further, the magnitude is larger when the exporting country is in financial crisis. Finally, I find that these effects on trade flows are large when the exporting country is a developed economy, but they are muted for developing economies.

Les travaux présentés dans cette thèse portent sur l'ordonnancement d'applications au sein d'un environnement de grille de calcul. Nous étudions comment mieux gérer les tâches au sein des intergiciels de grille, ceci dans l'objectif d'améliorer les performances globales de la plateforme. Les solutions que nous proposons se situent dans l'intergiciel, ce qui permet de conserver les architectures sous-jacentes sans les modifier. Dans un premier temps, nous proposons un mécanisme de réallocation permettant de prendre en compte dynamiquement les erreurs d'ordonnancement commises lors de la soumission de calculs. En effet, lors de la soumission sur une machine parallèle, il est souvent nécessaire de fournir une estimation du temps d'exécution afin que celle-ci puisse effectuer un ordonnancement. Cependant, les estimations ne sont pas précises et les décisions d'ordonnancement sont sans cesse remises en question. Le mécanisme de réallocation proposé permet de prendre en compte ces changements en déplaçant des calculs d'une machine parallèle à une autre. Le second point auquel nous nous intéressons dans cette thèse est l'ordonnancement d'une application de climatologie sur la grille. Afin de fournir les meilleures performances possibles nous avons modélisé l'application puis proposé des heuristiques spécifiques. Pour exécuter l'application sur une grille de calcul, l'intergiciel utilise ces connaissances sur l'application pour fournir le meilleur ordonnancement possible.

<p>The next generation satellite communication networks will provide multimedia services supporting high bit rate, mobility, ATM, and TCP/IP. In these cases, the satellite technology will act as the internetwork infrastructure of future global systems and assuming a global wireless system, no distinctions will exist between terrestrial and satellite communications systems, as well as between fixed and 3G mobile networks. In order for satellites to be successful, they must handle bursty traffic from users and provide services compatible with existing ISDN infrastructure, narrowcasting/multicasting services not offered by terrestrial ISDN, TCP/IP-compatible services for data applications, and point-to-point or point-to-multipoint on-demand compressed video services. This calls for onboard processing payloads capable of frequency multiplexing and demultiplexing and interference suppression.</p><p>This thesis introduces a new class of oversampled complex modulated filter banks capable of providing frequency multiplexing and demultiplexing. Under certain system constraints, the system can handle all possible shifts of different user signals and provide variable bandwidths to users. Furthermore, the aliasing signals are attenuated by the stopband attenuation of the channel filter thus ensuring the approximation of the perfect reconstruction property as close as desired. Study of the system efficient implementation and its mathematical representation shows that the proposed system has superiority over the existing approaches for Bentpipe payloads from the flexibility, complexity, and perfect reconstruction points of view. The system is analyzed in both SISO and MIMO cases. For the MIMO case, two different scenarios for frequency multiplexing and demultiplexing are discussed.</p><p>To verify the results of the mathematical analysis, simulation results for SISO, two scenarios of MIMO, and effects of the finite word length on the system performance are illustrated. Simulation results show that the system can perform frequency multiplexing and demultiplexing and the stopband attenuation of the prototype filter controls the aliasing signals since the filter coefficients resolution plays the major role on the system performance. Hence, the system can approximate perfect reconstruction property by proper choice of resolution.</p>

The next generation satellite communication networks will provide multimedia services supporting high bit rate, mobility, ATM, and TCP/IP. In these cases, the satellite technology will act as the internetwork infrastructure of future global systems and assuming a global wireless system, no distinctions will exist between terrestrial and satellite communications systems, as well as between fixed and 3G mobile networks. In order for satellites to be successful, they must handle bursty traffic from users and provide services compatible with existing ISDN infrastructure, narrowcasting/multicasting services not offered by terrestrial ISDN, TCP/IP-compatible services for data applications, and point-to-point or point-to-multipoint on-demand compressed video services. This calls for onboard processing payloads capable of frequency multiplexing and demultiplexing and interference suppression. This thesis introduces a new class of oversampled complex modulated filter banks capable of providing frequency multiplexing and demultiplexing. Under certain system constraints, the system can handle all possible shifts of different user signals and provide variable bandwidths to users. Furthermore, the aliasing signals are attenuated by the stopband attenuation of the channel filter thus ensuring the approximation of the perfect reconstruction property as close as desired. Study of the system efficient implementation and its mathematical representation shows that the proposed system has superiority over the existing approaches for Bentpipe payloads from the flexibility, complexity, and perfect reconstruction points of view. The system is analyzed in both SISO and MIMO cases. For the MIMO case, two different scenarios for frequency multiplexing and demultiplexing are discussed. To verify the results of the mathematical analysis, simulation results for SISO, two scenarios of MIMO, and effects of the finite word length on the system performance are illustrated. Simulation results show that the system can perform frequency multiplexing and demultiplexing and the stopband attenuation of the prototype filter controls the aliasing signals since the filter coefficients resolution plays the major role on the system performance. Hence, the system can approximate perfect reconstruction property by proper choice of resolution.

Interest in converting portions of the large volumes of flood control storage capacity in federal multiple-purpose reservoirs in Texas and elsewhere to water supply and other conservation purposes has been growing for some time. Evaluation of storage reallocations involving tradeoffs between flood control and conservation purposes in multiple-purpose, multiple-reservoir systems represents a new area for applying the Water Rights Analysis Package (WRAP) and Texas Water Availability Modeling (WAM) System. A system of 12 multiple-purpose reservoirs operated by the U.S. Army Corps of Engineers (USACE) and Brazos River Authority (BRA) was adopted as a case study in this research to develop and test expanded WRAP/WAM-based methods for analyzing modifications in reservoir storage allocations and related system operations. The research consisted of the following tasks: ? The Brazos River Basin WRAP input dataset from the Texas WAM System (Brazos WAM) has a 1940-1997 hydrologic period-of-analysis. The research included developing and applying methods to extend the period-of-analysis to 1900-2007 providing a better representation of river basin hydrology. The methodology developed could potentially be used to update the other river basin datasets in the statewide WAM System. ? The Brazos WAM has 3,830 control points, 670 reservoirs, and hundreds of water rights. The research included developing and applying methods to create a much easier-to-apply condensed dataset focused on the USACE/BRA reservoir system and associated water rights that have only 48 control points and 14 reservoirs. ? The WRAP/WAM System was developed based on a monthly computational time step. The research included applying developmental methodologies for converting a monthly model to a daily time step that includes disaggregation of monthly naturalized flows to daily flows, calibration of flow routing coefficients, and incorporation of forecasting in the simulation. ? The WRAP/WAM System is designed for assessing water supply reliabilities and stream flow and storage frequencies from the perspective of conservative purposes. The research added flood risk indices to the WRAP modeling system in order to address tradeoffs between flood control and conservation purposes. ? The WRAP/WAM-based simulation study performed with the modified WAM dataset developed in this research demonstrates the improvements in water supply capabilities and tradeoffs with flood control associated with various reservoir storage reallocation strategies and other modifications in reservoir system operations.

This study focuses on persuasive design concerning the household users&rsquo / energy saving behavior while using electrical household appliances for the housework. Household users form a balance at home determined by the household resources they have, and they do not want to change this fragile balance because it is established as a result of household users&rsquo / habitual behavior. It is crucial to persuade household users to save energy at home without disturbing the balance among resources. Persuasion becomes an effective tool at this stage. The study provides an efficient reallocation of the resources for energy saving behavior, which is supported by household resource reallocation and persuasion literature, and an empirical study.

In 2003, the Florida legislature appropriated funds to finance pilot programs (1012.231, Florida Statutes) to prepare for the 2004-2005 school year in which pay for performance initiatives were to be implemented in each district. Therefore, the purpose of this study was to examine and describe the planning, processes, and implications of a pilot career ladder program that was implemented into a large Florida school district in the spring of 2004. During data collection, the program was terminated therefore creating a second purpose that sought to describe residual implications of a program when it is discontinued. Data collected for this study were used to respond to six specific research questions. The first inquired about the planning process prior to implementation. Archival documents were used to determine whether research-based strategies were involved. The second through the fifth questions rely heavily on survey and structured interview data collected by the district and the primary researcher respectively and seek to determine critical perspectives from teachers and administrators regarding the career ladder including knowledge, fairness, and implications for school and district. The sixth question asks whether residual effects remain in place after an initiative has been terminated. Particularly, as a major finding, time for implementation was a theme throughout the study as most respondents were concerned about the short timeline this program had to develop fully. Stakeholder buy-in and understanding of program roles emerged from the data. However, the notion of a mentor that was given the time and resources was frequently mentioned as a benefit to new teachers and the school overall. Furthermore, respondents saw the potential long-term benefit of staff development that would allow highly trained master teachers to coach new and struggling teachers during the day in a clinical setting. There was evidence that this program did have an initial negative impact on the culture of the schools in the district. One unplanned aspect of this case study was the fact that the program was terminated at the state level. This had implications for all stakeholders and could be a strong factor in later implementations; therefore, this would require further study.

Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal

A partially parallel reconfigurable channel switch is constructed for use in DFBR. Its permutation can be changed while running without any interruption in the streams of data. Three approaches are tried: one based on asorting network, one based on memories and multiplexers and one based on a Clos network. Variants with the pattern stored in memories and in shift registers are tried. They are implemented in automatically generated Verilog and synthesized for an FPGA. Their cost in terms of area use, memory use and maximum clock frequency is compared and the results show that the Clos based approach is superior in all aspects and that pattern data should not be saved in shift registers. The work is open source and available for download at https://github.com/channelswitch/channelswitch. / En delvis parallel och delvis seriell kanalswitch för användning inom DFBR skapas. Dess permutation kan ändras medan den kör utan avbrott i dataströmmen. Tre alternativ undersöks: ett baserat ett sorteringsnätverk, ett baserat på minnen och multiplexrar och ett som baseras på Clos-nätverk. Versioner med mönsterdata sparad i skiftregister och i minnen prövas. De implementeras i automatiskt genererad Verilog och synthesiseras för en FPGA. Deras kostnad i areaanvändning, minnesanvändning och maximal klockfrekvens jämförs. Resultaten visar i princip att Clos-nätverken är bäst i alla avseenden och att mönsterdata ska sparas i RAM-minnen och inte i skiftregister. Arbetet är open source och kan laddas ner från https://github.com/channelswitch/channelswitch.