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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.
1

An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers

Courey, Karim Joseph 18 March 2008 (has links)
Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In these experiments, the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit was studied. From this data, the probability of an electrical short was estimated, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.
2

Some Properties of Empirical Risk Minimization over Donsker Classes

Caponnetto, Andrea, Rakhlin, Alexander 17 May 2005 (has links)
We study properties of algorithms which minimize (or almost minimize) empirical error over a Donsker class of functions. We show that the L2-diameter of the set of almost-minimizers is converging to zero in probability. Therefore, as the number of samples grows, it is becoming unlikely that adding a point (or a number of points) to the training set will result in a large jump (in L2 distance) to a new hypothesis. We also show that under some conditions the expected errors of the almost-minimizers are becoming close with a rate faster than n^{-1/2}.
3

The role of Sir Roderick Murchison in promoting the geographical and geological exploration of the British Empire and its sphere of influence, 1855-1871

Stafford, R. A. January 1985 (has links)
No description available.
4

An Empirical Test of a Theoretical Model of Surprise in Marketing

Unknown Date (has links)
The purpose of this research was to construct and empirically test a theoretical model of surprise and its impact on consumer affect and behavior. First the literature on the emotion of surprise was reviewed with particular emphasis on classification and process models of surprise. A theoretical model of surprise was constructed. A new concept called motivated meaning integration (MMI) was proposed. MMI takes place in a setting that includes the interaction of the appraisal process with factors such as environmental uncertainty and consumers’ individual differences. These interactions impact outcomes such as consumer affect and buying behavior. Ten hypotheses were derived from the theoretical model and empirically tested using several pretests and two main studies. The present research designed and evaluated several surprise manipulations and MMI manipulation checks to effectively test the proposed relationships. Participants were recruited from Amazon Mechanical Turk (Mturk). Although many of the hypotheses were not supported, some important ones were. The results provide some support that a consumer’s sense of personal control interacts with MMI to impact a consumer’s likelihood of choosing unknown or mystery products ( e.g. products in a known category such as beauty products but the actual products are selected by the company). Specifically, consumers who experienced a low sense of personal control (compared to a high sense personal control) were more likely to choose mystery products (vs. objectively similar known products) after they encountered surprise with mystery (vs. with known) elements. The results also provided some support that productivity orientation interacts with surprise appraisal to impact consumer affect. Particularly, consumers with high productivity orientation (vs. low) were more likely to experience higher positive affect after encountering surprise with mystery (vs. with known) elements. The primary implication for theory involves refining the conceptualization of surprise appraisal, especially fast MMI, and adopting adequate measure for testing it. The most relevant implication for marketing management is to offer products with mystery elements because consumers are more likely to choose additional mystery products. If this dissertation stimulates others to pursue research on surprise theory in marketing, my efforts to continue developing scientific theory will be worth it. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
5

Momentum Trading and Limits to Arbitrage

Armstrong, William 2012 May 1900 (has links)
An extensive body of research supports the momentum strategy's persistence but disagrees on the underlying source of its profitability. A key obstacle to distinguishing between behavioral and rational explanations of momentum is that mispricing is unobservable. This dissertation studies the endogenous relationship between momentum trading and mispricing. The basic idea is that momentum trades can impede arbitrage when they are in the opposite direction of arbitrage trades and reinforce arbitrage when they are in the same direction. A simple model suggests that when momentum trades reinforce the arbitrage process, momentum strategy returns contain relatively less mispricing than when momentum trades impede the arbitrage process. Empirical results show that an arbitrage-reinforcing strategy has significantly higher average returns that are largely related to risk and do not reverse in subsequent periods, while an arbitrage-impeding strategy exhibits significant long-term reversal consistent with more mispricing. Additional tests show that winners have higher future growth rates than losers consistent with cross-sectional differences in expected returns. Overall, the evidence suggests that momentum profitability is largely related to risk which is partially masked by mispricing. An important implication of this model is that, like noise traders, trading strategies that do not condition on relative value can impede arbitrage.
6

Towards a Unified Signal Representation via Empirical Mode Decomposition

Gao, Jiexin 20 November 2012 (has links)
Empirical mode decomposition was proposed recently as a time frequency analysis tool for nonlinear and nonstationary signals. Despite from its many advantages, problems such as “uniqueness” problem have been discovered which limit the application. Although this problem has been addressed to some extent by various extensions of the original algorithm, the solution is far from satisfactory in some scenarios. In this work we propose two variants of the original algorithm, with emphasis on providing unified representations. R-EMD makes use of a set of reference signals to guide the decomposition therefore guarantees unified representation for multiple 1D signals. 2D- BEMD takes advantage of a projection procedure and is capable of providing unified representation between a pair of 2D signals. Application of the proposed algorithms on different problems in biometric and image processing demonstrates promising results and indicates the effectiveness of the proposed framework.
7

Common risk factors in bank stocks

Viale, Ariel Marcelo 17 September 2007 (has links)
This dissertation provides evidence on the risk factors that are priced in bank equities. Alternative empirical models with precedent in the nonfinancial asset pricing literature are tested, including the single-factor Capital Asset Pricing Model (CAPM), three-factor Fama-French model, and Intertemporal Capital Asset Pricing Model (ICAPM). The empirical results indicate that an unconditional two-factor Intertemporal Capital Asset Pricing Model (ICAPM) model, that includes the stock market excess return and shocks to the slope of the yield curve, is useful in explaining the cross-section of bank stock returns. I find no evidence, however, that firm specific factors, such as size and book-to-market ratios, are priced in bank stock returns. These results have a number of practical implications for event studies of banking firms, estimation of bank cost of capital and investment performance, as well as regulatory initiatives to utilize market discipline to evaluate bank risk under Basel II.
8

Investigation and Analysis in Cross-Media Reception: Schubert, Goethe, and Others

Weed, Janelle Unknown Date
No description available.
9

Towards a Unified Signal Representation via Empirical Mode Decomposition

Gao, Jiexin 20 November 2012 (has links)
Empirical mode decomposition was proposed recently as a time frequency analysis tool for nonlinear and nonstationary signals. Despite from its many advantages, problems such as “uniqueness” problem have been discovered which limit the application. Although this problem has been addressed to some extent by various extensions of the original algorithm, the solution is far from satisfactory in some scenarios. In this work we propose two variants of the original algorithm, with emphasis on providing unified representations. R-EMD makes use of a set of reference signals to guide the decomposition therefore guarantees unified representation for multiple 1D signals. 2D- BEMD takes advantage of a projection procedure and is capable of providing unified representation between a pair of 2D signals. Application of the proposed algorithms on different problems in biometric and image processing demonstrates promising results and indicates the effectiveness of the proposed framework.
10

Investigation and Analysis in Cross-Media Reception: Schubert, Goethe, and Others

Weed, Janelle 11 1900 (has links)
Is there ever a simple place of convergence where two media coexist and interact equally? If one assumes that there is indeed a mental space where media convgerge and are understood simultaneously, what problems arise if an when one medium overrides the meaning of another? It is difficult to distinguish with precision what individuals respond to in the reception of media presented simultaneously. The relationship between music and text together is a complex one I aim to analyze in this thesis. Using the poet-composer combinations of Schubert and Goethe, and Britten and Donne, I will analyze the interaction between text and music. Additionally, I have conducted empirical studies in Edmonton and Munich to investigate the felt engagement of participants as well as any cultural differences that may be present in terms of how the media are received. I will also engage in a cultural analysis of the changes in pedagogical approches in public education that might make students more willing to appreciate areas of media that might otherwise be categorized by them as only academic.

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