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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Implementation of a fuzzy logic based set-point modulation scheme with SVC system applications

Howell, Steven 04 April 2013 (has links)
This thesis introduces a novel online set-point modulation (SPM) technique that employs fuzzy logic to adjust the timing and magnitude of control system set-points. After first applying fuzzy logic-enabled SPM to underdamped second order systems for testing purposes, the new scheme is then applied to an electromagnetic transient simulation model of Manitoba Hydro’s existing Ponton SVC system, and the results are then compared to the original SVC system that uses traditional control approaches. Conclusions show that fuzzy logic-based SPM improves the controlled voltage’s transient overshoot response to changes in the voltage set-point.
152

Superharmonic and multiply superharmonic functions and Jensen measures in axiomatic Brelot spaces

Alakhrass, Mohammad. January 2009 (has links)
We study quasi superharmonic functions in Brelot spaces and the relationship between a reduced function, and harmonic and Jensen measures. We introduce the concept of quasi multiply superharmonic functions on a product of two Brelot spaces and study their properties. A main result obtained is characterizing the quasi superharmonic functions in terms of harmonic, finely harmonic and Jensen measures. Then we prove that a quasi multiply superharmonic function on a product of Brelot spaces equals its lower semicontinuous regularization out side of a 2-negligible set. Further we give a sufficient condition on a Brelot space O under which O becomes an extension space for superharmonic functions. As a result we characterize the extreme Jensen measures in such spaces. Finally we study extreme Jensen measures relative to several classes of multiply superharmonic functions.
153

Alterations in executive functioning induced by repeated amphetamine exposure

Whelan, Jennifer M. 11 1900 (has links)
Chronic exposure to psychostimulants such as amphetamine (AMPH) can induce long-term disruptions in cognition via actions on prefrontal cortex dopamine. Previous work has shown that two types of executive functions, set shifting and working memory (WM), are disrupted by AMPH sensitization and that these cognitive domains are impaired in schizophrenics and stimulant abusers. We assessed the effects of AMPH sensitization on behavioural flexibility using a cross-maze set shifting task and a WM task using the delayed spatial win-shift (SWSh) task in Long Evans (LE) and Sprague Dawley (SD) rats. Rats were exposed to an AMPH sensitization regimen (15 AMPH or saline injections: 1-5 mg/kg every 2nd day, increasing the dose by 1 mg every 3rd injections) following habituation on the mazes. In experiment 1, LE and SD rats were initially trained on a visual cue discrimination. During the set shift, rats were required to shift from the previously acquired visual-cue-based strategy to a response strategy (e.g.; always turn left, ignore the visual cue). For the reversal, rats were trained to reverse their turn direction. AMPH treatment did not impair learning of the initial cue discrimination in either strain. However, AMPH treated rats learned the response discrimination faster than controls during the set shift and AMPH treated LE rats were faster than controls to reach acquisition criterion during the response reversal. AMPH treatment neither impaired nor improved reversal learning in SD rats. In experiment 2, rats were tested on the SWSh task in which spatial information acquired during a training phase was used 30 minutes later during the testing phase in order to retrieve food pellets on the maze. In this task, AMPH treated rats were faster to re-attain criterion than control rats. Correlational analysis further revealed that AMPH sensitized rats that required more days to reach criterion before AMPH treatment (i.e. slow learners) tended to make more errors during re-acquisition of the memory task. Viewed collectively, these results suggest that chronic AMPH treatment can enhance behavioural flexibility and WM assessed in this manner. However, repeated AMPH exposure may have exacerbated pre-existing cognitive deficits in slow learning rats.
154

Multimapping Abstraction and State-set Search Theory

Pang, Bo Unknown Date
No description available.
155

Effects of mindset on relationship illusions

Gagné, Faby. January 1998 (has links)
This study investigated Gollwitzer's mindset theory in the context of romantic relationships. One-hundred and sixty-eight students involved in a dating relationship were asked either to deliberate about or to think of implementing a goal not related to their relationship (e.g., finding a summer job) or a goal related to their relationship (e.g., moving in with their romantic partner). All participants subsequently completed assessments of current affect, perceptions of partner and of optimism for the future of the relationship. In line with Taylor and Gollwitzer (1995), thinking about implementing a decided goal not related to the relationship was found to increase positive affect and relationship illusions compared to non-relationship goal deliberation. In contrast, among those in the relationship mindset conditions, deliberation was found to elicit greater relationship illusions compared to goal implementation. These results help to delineate between effects of relationship specific and non relationship specific mindsets on relationship appraisals.
156

Implementation of a fuzzy logic based set-point modulation scheme with SVC system applications

Howell, Steven 04 April 2013 (has links)
This thesis introduces a novel online set-point modulation (SPM) technique that employs fuzzy logic to adjust the timing and magnitude of control system set-points. After first applying fuzzy logic-enabled SPM to underdamped second order systems for testing purposes, the new scheme is then applied to an electromagnetic transient simulation model of Manitoba Hydro’s existing Ponton SVC system, and the results are then compared to the original SVC system that uses traditional control approaches. Conclusions show that fuzzy logic-based SPM improves the controlled voltage’s transient overshoot response to changes in the voltage set-point.
157

Examining the role of retrieval processes in set-alternation costs

Wong, Jady 02 October 2013 (has links)
The goal of the experiments was to evaluate an explanation of set-alternation costs based on episodic memory principles. The assumption is that performance of any task is a consequence of memory retrieval processes that involve representations of specific prior experiences (Kolers, 1976; Leboe, Whittlesea, & Milliken, 2005; Neill & Mathis, 1998; Tenpenny, 1995; Whittlesea, 1997; Whittlesea & Jacoby, 1990). When the Event 1 and 3 targets mismatch the retrieval of the Event 1 memory episode is not entirely appropriate for performing the Event 3 task. The interference due to a partial match between Events 1 and 3 might be the source of set-alternation costs. Results of Experiment 1 revealed larger costs in the high probability set-alternation condition. The high probability set-alternation condition encouraged retrieval of Event 1. However, because the targets of Event 1 and 3 mismatched the retrieval of Event 1 interfered with the processing of Event 3’s task-set. In other words, the interference due to a match in task-sets but a mismatch in targets generated costs. If set-alternations costs originate from a partial match between Events 1 and 3, increasing the amount of overlapping information between these events should reduce costs. The findings of Experiments 2 and 3 showed reduced set-alternation costs when there was a target identity match between Events 1 and 3. Lastly, Experiment 4 showed that set-alternation costs are larger when the retrieval of the Event 1 memory episode is obstructed. That is, costs were larger when there was a combination of obstructed Event 1 retrieval and a partial match between Events 1 and 3.
158

Embedding a Planar Graph on a Given Point Set

MONDAL, DEBAJYOTI 02 1900 (has links)
A point-set embedding of a planar graph G with n vertices on a set S of n points is a planar straight-line drawing of G, where each vertex of G is mapped to a distinct point of S. We prove that the point-set embeddability problem is NP-complete for 3-connected planar graphs, answering a question of Cabello [20]. We give an O(nlog^3n)-time algorithm for testing point-set embeddability of plane 3-trees, improving the algorithm of Moosa and Rahman [60]. We prove that no set of 24 points can support all planar 3-trees with 24 vertices, partially answering a question of Kobourov [55]. We compute 2-bend point-set embeddings of plane 3-trees in O(W^2) area, where W is the length of longest edge of the bounding box of S. Finally, we design algorithms for testing convex point-set embeddability of klee graphs and arbitrary planar graphs.
159

On arithmetic in free monoids.

Zeamer, Richard Warwick January 1972 (has links)
No description available.
160

Examining the role of retrieval processes in set-alternation costs

Wong, Jady 02 October 2013 (has links)
The goal of the experiments was to evaluate an explanation of set-alternation costs based on episodic memory principles. The assumption is that performance of any task is a consequence of memory retrieval processes that involve representations of specific prior experiences (Kolers, 1976; Leboe, Whittlesea, & Milliken, 2005; Neill & Mathis, 1998; Tenpenny, 1995; Whittlesea, 1997; Whittlesea & Jacoby, 1990). When the Event 1 and 3 targets mismatch the retrieval of the Event 1 memory episode is not entirely appropriate for performing the Event 3 task. The interference due to a partial match between Events 1 and 3 might be the source of set-alternation costs. Results of Experiment 1 revealed larger costs in the high probability set-alternation condition. The high probability set-alternation condition encouraged retrieval of Event 1. However, because the targets of Event 1 and 3 mismatched the retrieval of Event 1 interfered with the processing of Event 3’s task-set. In other words, the interference due to a match in task-sets but a mismatch in targets generated costs. If set-alternations costs originate from a partial match between Events 1 and 3, increasing the amount of overlapping information between these events should reduce costs. The findings of Experiments 2 and 3 showed reduced set-alternation costs when there was a target identity match between Events 1 and 3. Lastly, Experiment 4 showed that set-alternation costs are larger when the retrieval of the Event 1 memory episode is obstructed. That is, costs were larger when there was a combination of obstructed Event 1 retrieval and a partial match between Events 1 and 3.

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