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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.
171

The Neuropsychological Mechanisms of Avoidant Coping Post Traumatic Brain Injury

Krpan, Katherine Maria 13 April 2010 (has links)
Many people who sustain traumatic brain injuries (TBI) have poor psychosocial outcomes. Previous research has indicated that poor outcomes are related to the use of avoidant coping following TBI, although the mechanisms of this relationship are not clear. The major pathological consequence of TBI is damage to the frontal lobes and/or their connections, resulting for most people in executive and/or affective dysfunction. The purpose of this dissertation study was to delineate the neuropsychological, psychiatric, personality and physiological mechanisms of avoidant coping following TBI. Controls and people with TBI completed the Baycrest Psychosocial Stress Test (BPST), where coping behaviour was observed directly, and physiological measures were recorded. Participants also completed a neuropsychological test battery, and a series of questionnaires assessing coping, psychiatric status, personality and outcomes. There were no significant differences between groups in self reported coping. However, the control and mild TBI group engaged in more planful than avoidant behaviour on the BPST. As a group, individuals with moderate-to-severe injury, in contrast, engaged in more avoidant than planful behaviour. However, analysis of individual differences in coping behaviour within the moderate-to-severe group revealed a bimodal distribution, allowing classification of people in this group as ‘planners’, or ‘avoiders’ (this distribution was not evident in the mild TBI group). Within the moderate-to-severe group, planners had better executive function, were more reactive to stress (psychologically and physiologically), performed better on the speech task during the BPST, and had greater return to productivity. However, planners also had worse psychosocial outcomes as compared to the avoiders. This was the first study, to the author’s knowledge, to examine coping behaviour during a simulated real-world stress test. Results indicate that behavioural measures of coping, such as the BPST, are more sensitive to changes in coping post TBI than are self and significant other reported questionnaires. Results also demonstrate that executive function and psychological and physiological reactivity are important factors that contribute to coping following moderate-to-severe TBI. These data raise important questions about the challenges of targeting coping through rehabilitation.
172

The Neuropsychological Mechanisms of Avoidant Coping Post Traumatic Brain Injury

Krpan, Katherine Maria 13 April 2010 (has links)
Many people who sustain traumatic brain injuries (TBI) have poor psychosocial outcomes. Previous research has indicated that poor outcomes are related to the use of avoidant coping following TBI, although the mechanisms of this relationship are not clear. The major pathological consequence of TBI is damage to the frontal lobes and/or their connections, resulting for most people in executive and/or affective dysfunction. The purpose of this dissertation study was to delineate the neuropsychological, psychiatric, personality and physiological mechanisms of avoidant coping following TBI. Controls and people with TBI completed the Baycrest Psychosocial Stress Test (BPST), where coping behaviour was observed directly, and physiological measures were recorded. Participants also completed a neuropsychological test battery, and a series of questionnaires assessing coping, psychiatric status, personality and outcomes. There were no significant differences between groups in self reported coping. However, the control and mild TBI group engaged in more planful than avoidant behaviour on the BPST. As a group, individuals with moderate-to-severe injury, in contrast, engaged in more avoidant than planful behaviour. However, analysis of individual differences in coping behaviour within the moderate-to-severe group revealed a bimodal distribution, allowing classification of people in this group as ‘planners’, or ‘avoiders’ (this distribution was not evident in the mild TBI group). Within the moderate-to-severe group, planners had better executive function, were more reactive to stress (psychologically and physiologically), performed better on the speech task during the BPST, and had greater return to productivity. However, planners also had worse psychosocial outcomes as compared to the avoiders. This was the first study, to the author’s knowledge, to examine coping behaviour during a simulated real-world stress test. Results indicate that behavioural measures of coping, such as the BPST, are more sensitive to changes in coping post TBI than are self and significant other reported questionnaires. Results also demonstrate that executive function and psychological and physiological reactivity are important factors that contribute to coping following moderate-to-severe TBI. These data raise important questions about the challenges of targeting coping through rehabilitation.
173

Spreading of wave packets in lattices with correlated disorder / Spridning av v ̊agpaket i gitter med korrelerad oordning

Rönnbäck, Jakob January 2011 (has links)
It is known that a highly ordered medium allows certain wave functions to move unhindered throughout and in this manner achieve delocalization. It is also known that if one introduces disorder into a medium, wave packets will not be able to move as freely and will instead be trapped or localized. In this thesis, I have simulated a medium in which the amount of disorder can be modified and using this I have shown that the shape of the localization can be altered.
174

An Empirical Study on the Existence Value of Stock Index Futures :Hedging and Speculating Functions

Hsieh, Cheng-yen 20 June 2012 (has links)
By the time of 2011, Taiwan Futures Exchange has issued 8 kinds of stock index futures. By taking a closer look at the transaction of the index futures, we found out that, in terms of trading volume, there is a significant difference among each others. Based on the observation, our research focuses on studying the existence value of the index futures in terms of hedging and speculating functions. The definition of futures¡¦ existence value is that the investors can use the futures to achieve the objectives of hedging and speculating in financial market. The research objects are TX, TE, TF, MTX, XIF, and GTF. The method to measure the hedging function is based on Portfolio and Hedging Theory of Johnson (1959). We estimate the hedging ratio with different data periods to calculate the hedging effectiveness. The method to measure the speculating function is based on the theory of Rutledge (1979) et al. We calculate the speculating trading volume to study the relationship with the basis by using OLS model. The empirical result shows that, in the hedging function, all of the index futures¡¦ hedging ratios are almost less than 1, and all have high hedging effectiveness. There is no significant influence on hedging effectiveness with different data periods and issuing time. In the speculating function, TX, MTX, and GTF will make speculating activities increase when the basis get bigger but TE, TF, and XIF will not. To sum up, TX, MTX, and GTF have higher existence value than TE, TF, and XIF. At last, based on the observation from this study, we propose several policy suggestions for enhancing the existence value of the index futures in financial market.
175

Simulation of vertical ship responses in high seas

Rajendran, Suresh 15 May 2009 (has links)
This research was done to study the effect of sea severity on the vertical ship responses like heave and pitch. Model testing of a 175m moored container ship with zero heading speed was done for different sea states varying from very rough to very high seas. Transfer functions were extracted using Volterra model which constitutes both linear and quadratic part. The experimental linear transfer functions were calculated using Volterra linear model and were compared with linear transfer function from the hydrodynamic theory. Experimental second order transfer functions were also extracted using Volterra quadratic model and their behavior was studied for different sea states. After the extraction of linear and second order transfer functions total responses were reconstructed and compared with the measured responses. This also helped to investigate the contribution of second order part to the total vertical ship responses. In the last stage of the research a new semi- empirical method was developed called as ‘UNIOM’ for the prediction of the responses. Laboratory input waves and theoretical LTFs were used for the simulation of ship response and these were compared with measured responses.
176

On Planar Functions

Hamidli, Fuad 01 September 2011 (has links) (PDF)
The notion of &rdquo / Planar functions&rdquo / goes back to Dembowski and Ostrom, who introduced it in 1968 first time to describe projective planes with special properties in finite geometry. Recently, they attracted an interest from cryptography because of having an optimal resistance to differential cryptanalysis.This thesis is based on the paper &rdquo / New semifields, PN and APN functions&rdquo / by J&uuml / rgen Bierbrauer. The whole purpose of this thesis is to understand and present a detailed description of the results of the paper of Bierbrauer about planar functions. Here and throughout this thesis &rdquo / new&rdquo / means &rdquo / new&rdquo / in the paper of Bierbrauer. In particular we have no new constructions here and we only explain the results of Bierbrauer.
177

Explicit Formulas and Asymptotic Expansions for Certain Mean Square of Hurwitz Zeta-Functions: III

MATSUMOTO, KOHJI, KATSURADA, MASANORI 05 1900 (has links)
No description available.
178

Extend Depth Of Field From A Lens System Using A Phase Mask

Hsu, Chun-hsiang 08 July 2009 (has links)
A method using a phase mask to extend the depth of field for an incoherent lens system is presented. This phase mask is designed to generate a point spread function in which the intensity distribution is invariant to misfocus. Thus, image could be retrieved by de-convoluting the misfocused one. Its application to 3D profile sensing using point white light illumination is presented as well. A fringe pattern is projected onto the inspected surface using the point white light source. Fringe distribution is then observed by a CCD camera through the presented phase mask at a different viewpoint. Phase can be extracted by the Fourier transform method or the phase-shifting technique. With triangulation methods or proper calibration approaches, depth information can be identified from the phase of the fringes. The phase mask enlarges the depth of field of the image acquisition system, while the point white light illumination increases the depth of focus of the fringe projection system. Thus, a highly accurate, non-scanning projected fringe profilometer with large depth measuring range can be realized.
179

Regular aerobic exercise and cognitive function : the roles of vascular function and plasma insulin

Tarumi, Takashi 20 November 2012 (has links)
There is an increasing recognition that vascular disease risk is associated with a greater incidence of cognitive impairment and dementia. Such link is supported by the physiological observation that cerebral metabolism heavily relies on vascular supply of oxygen and energy substrates. Cerebral hypoperfusion which results from vascular dysfunction causes a mismatch between energy demand and supply and is associated with the pathological features of dementia, including the impairments of action potential generation and protein synthesis, glutamatergic excitotoxicity, and the deposition of cerebral amyloid-β proteins. In contrast, habitual aerobic exercise is an established strategy to ameliorate the risk factors for vascular disease and is increasingly recognized in improving cognitive function. Accordingly, the primary purpose of this dissertation study was to investigate whether the exercise-related improvement in cognitive function was attributable to ameliorated vascular function and risk factors for vascular disease. In order to address this as comprehensively as we could, both cross-sectional and interventional studies were conducted. The primary findings from the present study were as follows. In the cross-sectional study, a greater cognitive performance observed in endurance-trained adults was associated with higher levels of cerebral CO2 reactivity and brachial endothelium-dependent vasodilation and lower levels of central arterial stiffness and plasma insulin. In the interventional study, a 3-month aerobic exercise training intervention did not improve cognitive function although central arterial stiffness and brachial endothelium-dependent vasodilation made favorable changes. However, we found that the improvement in memory performance after aerobic exercise training was associated with the reduction in central systolic blood pressure. Taken together, a better cognitive performance observed in endurance-trained adults may not directly be attributable to greater vascular function because there were discrepant changes in cognitive and vascular functions after a 3-month aerobic exercise intervention. The correlation between the changes in memory performance and central systolic blood pressure is interesting but needs further investigation using a larger sample size. The discrepancy in the results between the cross-sectional and interventional studies could be explained by the duration of exercise training and/or the time it takes for the effect of improved vascular function to translate into cognitive function. / text
180

A TRANSLOG COST FUNCTION ANALYSIS OF INPUT SUBSTITUTION IN THE U.S. COPPER SMELTING INDUSTRY 1960 - 1991

Pitts, Morris Michael January 2005 (has links)
The copper smelting industry has under gone extreme change over the past three decades. These changes have reordered dramatically the demand for inputs and the way in which those inputs have been utilized. The stimulus for change has come from multiple sources, and chief among these stimuli has been the mandate to sharply curtail the atmospheric release of sulfur dioxide. Even though the total emissions were lower than those from steam generation of electricity and from the refinery and petro-chemical industry, the perceived local and regional impact of sulfur dioxide forced extreme changes in the utilization of fundamental inputs of capital, labor, energy and materials.This study attempts to analyze these input use changes by modeling the industry as a translog cost function and by generating a number of associated elasticities. In addition to the four basic inputs, the model includes as control variables output, and other variables that represent pollution abatement and technical change.The challenge of estimating a large model on a limited number of observations has delivered information that is more limited in scope than was originally desired. The proxy for technical change did not produce significant parameters and the pollution abatement proxy is limited in its participation in the results. The range of elasticities computed reveal a picture of an industry characterized by inelasticity, in general, labor and energy being part of the exceptions. The industry is found to be sensitive to output level in its degree of elasticity among inputs.The translog model is found to be an effective tool for industry analysis. The promise of detailed analytical information may be even greater at the firm level where data are more accurate and the number of observations far greater.

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