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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.
561

The Posterior Bed Nucleus of the Stria Terminalis Mediates Opposite-Sex Odor Preference in Male Syrian Hamsters (Mesocricetus Auratus)

Been, Laura Elizabeth 11 November 2008 (has links)
In Syrian hamsters, social behavior is mediated exclusively by chemosensory cues and circulating gonadal steroid hormones. Where these two signals are processed in the brain is unknown, but the posterior bed nucleus of the stria terminalis (pBNST) has been suggested as a candidate site. Therefore, we tested male hamsters’ preference for opposite-sex odors following excitotoxic lesions of the pBNST. Lesions of the pBNST (pBNST-X) eliminated male hamsters’ preference for opposite-sex odors. Furthermore, pBNST-X males spent significantly less time investigating female odors than clean odors and significantly less time investigating female odors than control males did. Lesions of the pBNST did not change male hamsters’ investigation of male odors. The deficits observed in pBNST-X males were not due to a failure to discriminate between odors, as pBNST-X males were able to distinguish between odors. Together, these data suggest the pBNST is critical for opposite-sex odor preference in male hamsters.
562

Supply Chain Design - Competitive and Financial Perspectives

Sanajian, Nima 28 February 2013 (has links)
In this thesis we study problems in the context of inventory control and facility location. In chapter 2 we study the competition among risk averse newsvendors. We showed that the well-known result for the single-product monopoly firm, which states higher risk aversion causes the firm to reduce its order quantity, cease to hold under the competition. We concluded that the higher risk aversion does not necessarily cause both firms to reduce their order quantity. We showed that the impact of risk aversion on equilibrium quantities is a trade-off between two effects: (a) Own risk aversion increment which causes that the firm reduces its order quantity and (b) Effect of spillover demand from competitor which causes that the firm increases its order quantity. We also show which firm raises its order quantity as both firms become more risk averse depending on their attributes: profitability ratio (overstocking to understocking ratio), initial risk aversion level and demand characteristic (distribution and substitution). In Chapter 3, we study how the operational decisions of a firm's manager depend on her own incentives, the capital structure, and financial decisions in the context of the newsvendor framework. We showed that in contrast to common practices, tying the manager's compensation to stock price (equity value) may not be optimal for shareholders. We propose to tie the managers' compensation to the firm value or include a debt-like instrument in the compensation package to mitigate the risk taking behaviour of the managers. We also show how the board of directors can modify the compensation structure based on the state of the economy and publicly available information about company's demand. In Chapter 4, we study the effect of risk attitude of decision makers on well-known location problems with uncertain demand. In addition to providing mathematical formulations for those problems, we also discussed how we can solve these problems using linearization techniques. We also shed some light on the importance of considering the volatility and correlation structure. Furthermore, we apply a Bayesian updating method, a useful tool for updating the probability distribution to incorporate the consultants' view about uncertain factors in location problems.
563

A Study in Preference Elicitation under Uncertainty

Hines, Greg January 2011 (has links)
In many areas of Artificial Intelligence (AI), we are interested in helping people make better decisions. This help can result in two advantages. First, computers can process large amounts of data and perform quick calculations, leading to better decisions. Second, if a user does not have to think about some decisions, they have more time to focus on other things they find important. Since users' preferences are private, in order to make intelligent decisions, we need to elicit an accurate model of the users' preferences for different outcomes. We are specifically interested in outcomes involving a degree of risk or uncertainty. A common goal in AI preference elicitation is minimizing regret, or loss of utility. We are often interested in minimax regret, or minimizing the worst-case regret. This thesis examines three important aspects of preference elicitation and minimax regret. First, the standard elicitation process in AI assumes users' preferences follow the axioms of Expected Utility Theory (EUT). However, there is strong evidence from psychology that people may systematically deviate from EUT. Cumulative prospect theory (CPT) is an alternative model to expected utility theory which has been shown empirically to better explain humans' decision-making in risky settings. We show that the standard elicitation process can be incompatible with CPT. We develop a new elicitation process that is compatible with both CPT and minimax regret. Second, since minimax regret focuses on the worst-case regret, minimax regret is often an overly cautious estimate of the actual regret. As a result, using minimax regret can often create an unnecessarily long elicitation process. We create a new measure of regret that can be a more accurate estimate of the actual regret. Our measurement of regret is especially well suited for eliciting preferences from multiple users. Finally, we examine issues of multiattribute preferences. Multiattribute preferences provide a natural way for people to reason about preferences. Unfortunately, in the worst-case, the complexity of a user's preferences grows exponentially with respect to the number of attributes. Several models have been proposed to help create compact representations of multiattribute preferences. We compare both the worst-case and average-case relative compactness.
564

Isovist Analysis as a Tool for Capturing Responses Towards the Built Environment

Dzebic, Vedran January 2013 (has links)
Experience of the built-environment is said to be dependent on visual perception and the physical properties of space. Scene and environmental preference research suggests that particular visual features greatly influence one’s response to their environment. Typically, environments which are informative and allow an individual to gain further knowledge about their surroundings are preferred. Although, such findings could be applied to the design process it is first necessary to develop a way in which to accurately and objectively describe the visual properties within an environment. Recently it has been proposed that isovist analysis could be employed to describe built-environments. In two experiments we examined whether or not isovist analysis can capture experience of real-world environments. In Experiment one we demonstrated that isovist analysis can be employed to describe experience of environment within a controlled, laboratory environment. In Experiment two we employed some of the methods of post-occupancy analysis to examine the robustness of the isovist approach and whether it would capture experience of a complex, real-world environment. The results of Experiment two suggest that isovist analysis could capture certain experiences, such as spaciousness, but failed to capture other responses. Regression analysis suggests that a large number of variables predicted experience, including previous experience with the building and the presence of other individuals. These findings suggest that experience of real-world, complex environments cannot be captured by the visual properties alone, but also highlight some of the other factors, such as presence of others and previous experiences may influence experience of built settings. Implications for the design processes are described.
565

The Effects Of Multiple Representations-based Instruction On Seventh Grade Students&#039 / Algebra Performance, Attitude Towards Mathematics, And Representation Preference.

Akkus Cikla, Oylum 01 December 2004 (has links) (PDF)
The purpose of this study was to investigate the effects of multiple representations-based instruction on seventh grade students&amp / #8217 / algebra performance, attitudes toward mathematics, and representation preference compared to the conventional teaching. Moreover, it was aimed to find out how students use multiple representations in algebraic situations and the reasons of preferring certain modes of representations. The study was conducted in four seventh grade classes from two public schools in Ankara in the 2003-2004 academic year, lasting eight weeks. For assessing algebra performance, three instruments called algebra achievement test, translations among representations skill test, and Chelsea diagnostic algebra test were used. To assess students&amp / #8217 / attitudes towards mathematics, mathematics attitude scale, to determine students&amp / #8217 / representation preferences before and after the treatment representation preference inventory were administered. Furthermore, as qualitative data, interview task protocol was prepared and interviews were carried out with the students from experimental and control classes. The quantitative analyses were conducted by using multivariate covariance analyses. The results revealed that multiple representations-based instruction had a significant effect on students&amp / #8217 / algebra performance compared to the conventional teaching. There was no significant difference between the experimental and control groups in terms of their attitudes towards mathematics. The chi square analyses revealed that treatment made a significant contribution to the students&amp / #8217 / representation preferences. The results of the interviews indicated that the experimental group students used variety of representations for algebra problems and were capable of using the most appropriate one for the given algebra problems.
566

Predictors Of Disordered Eating Among Turkish University Students

Pembecioglu, Umit 01 January 2005 (has links) (PDF)
The purpose of the present study is twofold: First, to assess to what extent gender, age, body mass index, weight satisfaction, body satisfaction and coping styles predict disordered eating attitudes of Turkish university students. Second, to examine whether there is a significant difference between female and male university students&rsquo / expert preference in case of a weight problem and importance of significant other&rsquo / s opinion regarding their weight. Three instruments- Eating Attitudes Test, Coping Styles Inventory, and a Demographic Data Form were administered to 525 students from four (3 state, 1 private) universities of Ankara. A stepwise multiple regression analysis was conducted to evaluate how well emotion focused coping, problem focused coping, gender, age, body mass index, weight satisfaction and body satisfaction predicted the disordered eating attitudes of Turkish university students. A two way contingency table analysis was conducted to evaluate whether there was a significant difference between female and male university students regarding their expert preference in case of a weight problem, and whether there was a significant difference between female and male university students with respect to the importance of significant other&rsquo / s opinion regarding their weight. The variables found to be most predictive of disordered eating attitudes and entered the regression equation were weight satisfaction, gender, emotion focused coping, age, and body mass index. Of the five variables, weight satisfaction was strongly negatively related to disordered eating attitudes. Results indicated that proportions of female students preferring dietitian and fitness expert in case of a weight problem were nearly same, whereas male students prefered fitness expert, medical doctor and dietitian, respectively. Regarding the importance of significant other&rsquo / s opinion in relation to weight, there were no significant differences between two groups. Opposite sex friend&rsquo / s opinion in relation to weight was found to be the most important source for both female and male students.
567

Valuation of irrigation water in southern Alberta: a stated preference approach

Wang, Yihong 06 1900 (has links)
The research presented in this thesis focuses on determining the value of irrigation water in southern Alberta. Utilizing a stated preference method, the research represents a successful attempt at applying contingent behavior scenarios to estimate irrigation water supply and demand, and thus irrigators willingness to pay/accept (WTP/WTA) for water through a hypothetical water market during droughts. The research also aims to assess the effectiveness of water markets in conserving water and promoting water productivity and efficiency. The findings reveal that irrigators WTP during droughts is within the range of $1.22-4.90/acre-inch ($0.012-$0.048/m3), varying over various levels of water scarcity. It is found that the presence of water markets plays a crucial role in water reallocation and improves water productivity and efficiency, the extent of which depends on how active are water markets. / Agricultural and Resource Economics
568

非補償型意思決定方略を表現するためのデータマイニング手法の適用に関する分析

山本, 俊行, YAMAMOTO, Toshiyuki 07 1900 (has links)
No description available.
569

The benefits of viewing sacred versus preferred landscapes

Burger, Donald Allen 05 1900 (has links)
Restoration landscape theories propound the observation that landscape mitigates human emotion, mental functioning, and behaviour. Those environments that positively affect these spheres are called "restorative". In recent years, many attempts have been made to quantify restorative landscapes, so that landscape architects and others can replicate them in the manipulated environment. An understanding of how certain combinations of landscape attributes affect humans is important in knowing the ramifications of certain designs. A major finding in recent years is that preferred landscapes—or those high in scenic beauty—are generally more restorative than less-attractive environments. One realm of the environment not dealt with, however, is the sacred landscape. One reason for this is the relative difficulty in narrowing down the term “sacred” to something measurable. The purpose of this thesis is to investigate the nature of sacred landscapes, and then to test sacred landscapes against preferred landscapes to measure their restorative potential. This testing involved subjecting participants to a psychological stressor, and then exposing them to slides rated highly in either sacredness or preference. A control group was also tested, but viewed a blank screen rather than images. Implications of this research impact both researchers and practitioners in the fields of landscape architecture, environmental psychology, public land management, and visual resource management. This study found that sacred landscapes are very restorative, although not quite as restorative as environments that rate highly in scenic beauty. This confirms previous research efforts, and opens the study of restorative environments to other landscape typologies as well.
570

Team role balance : investigating knowledge-building in a CSCL environment

Roberts, Alan January 2007 (has links)
Computer Supported Collaborative Learning (CSCL) is one approach that seemingly maps neatly to the notion of equipping learners for emergent knowledge-age work practice currently exemplified by Computer Supported Cooperative Work (CSCW) or Virtual Teams. However, the difficulty of achieving peer interaction in Computer Supported Collaborative Learning (CSCL) environments has proved to be a recurrent problem. Seemingly collaborative settings have been interpreted too narrowly referring only to positive phenomenon. There has been a tendency to focus on technology rather than social scaffolds. Little is known about the influence of students' personalities on online collaborative interaction and knowledge-building activity. Within collaborative team based contexts individuals demonstrate preferences towards certain activities. Such preferences and combinations of preferences may affect team knowledge-building activity both in terms of quality and efficiency. This thesis reports on the findings from a study that investigated if knowledge-building activity can be enhanced in tertiary education CSCL environments through the use of teams balanced by Team Role Preference.

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