This dissertation investigates three issues on business failure causality and prediction. First, a nonlinear model for mathematical programming based discriminant analysis is studied. This study proposes a nonlinear model that builds on the existing linear and quadratic models and allows for a more flexible degree of nonlinearity through a set of power parameters. The proposed nonlinear model is solved using a genetic algorithm and is tested against linear and quadratic models using real financial data. The results show that each model is better in certain cases, but the nonlinear model turns out to be the best overall among the three. Better performance of this nonlinear model appears likely, but a more robust solver would be required. Second, the relationship between aggregate business failures and macroeconomic conditions is studied from a causality perspective. A structural Vector Autoregression (VAR) is used while incorporating the recently developed causal inference method Directed Acyclic Graph (DAG). Particularly, DAG is used to provide a contemporaneous causal structure and the VAR results are summarized using innovation accounting techniques. The results show that during the period from 1980 to 2004 in the U.S., aggregate business failures were influenced by interest rates, but overall these failures appear to be far more exogenous than was found previously. Third, the effect of incorporating macroeconomic variables into business failure prediction models is investigated with a focus on the U.S. airline industry from 1995 to 2005. The attention is placed on prediction accuracy, parameter stability, and the effect of particular macroeconomic variables. The results show that the stability of parameters in the prediction model is improved when macro variables are added. In terms of prediction accuracy, the model augmented with a macro variable performed better in a jackknife prediction, but not in out-of-sample predictions. The macroeconomic variable found to be significant is the change of interest rate, which is probably related to the high level of leverage common in this particular industry. Also, the results demonstrate that a probability score can be used as a more informative evaluation measure than the current one based on cutoff probabilities.

This study examines the failure firm¡¦s stock risk character and return behavior prior announcements day. This study includes three parts. First, we examine the risk different between failure firms and control firms. Second, we analysis the returns character of failure firms, and third, we test whether the different judgment announcements will affect the failure firms¡¦ stock return. We examine the daily stock returns between 1997 and 1999, 26 failure firms and 50 control firms have been observed. The empirical results can be summarized as follows: 1. Systematic risk behaves quite differently for the failure and control groups as much as two years before failure. 2. Both the total variance and the firm-specific variance behave quite differently for the failure and control groups only two months before failure. 3. The market is effective before announcements and not effective after announcements. 4. The shareholders of failure firms lost between different judgment announcements are no different in a short time. 5. The magnitude of the price reaction to failure filings depend on the probability of bankruptcy and proxy for predisclosure information impounded in stock prices over the year prior to failure filing.

Thesis (MNutr)--University of Stellenbosch, 2008. / Bibliography. Also available via the Internet.

Thesis (Ed. Spec.)--University of Wisconsin--Stout, 2003. / Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 261-290). Available also in a digital version from Dissertation Abstracts.

Thesis (M. Nurs.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 60-64).

Most models developed for hydraulic fracturing in unconsolidated sands are based on Linear Elastic Fracture Mechanics (LEFM) and tensile fracture (Mode I fracture). However, in unconsolidated sand formations the field data shows that LEFM based models cannot properly predict the fracture behavior. Hydraulic fracture lab experiments in a true triaxial setup which was made as a part of this study are designed to investigate the failure mechanism around the crack tip in unconsolidated sands and effects of fluid rheology, leak off, and stress state are investigated. The results show that two mechanisms of tensile and shear failure are involved in fracture propagation in unconsolidated sands and depending on the fracturing fluid rheology and stress state of the formation one or both of them can happen at the crack tip. Several experiments with different fracturing fluids, rates, and different stress boundary conditions are categorized into two major categories based on whether we have a fracture or not. A subsequent categorization is used to categorize the fractured cases into Tensile Failure, Shear Failure and Mixed Failure categories. First the experimental observations are presented and subsequently observations are analyzed and compared in order to explain the observations and conclusions. ;Tensile failure category is happening in medium viscosity fracturing fluids in the order of 20,000 cP viscosity at unit 1/s shear rate. Shear failure category is mostly taking place in low viscosity fluids (200 cP viscosity at unit 1/s shear rate). Mixed mode fracturing is happening in high viscosity fluids (70,000 cP viscosity at unit 1/s shear rate) with high stress anisotropy. However, the same fluid will give a No Fracture result in the case of isotropic or near isotropic stress state. It is shown that higher stress anisotropy increases the tendency of shear failure and at the same time, the resulting fracture will propagate in a preferential direction. However, tilting and branching might happen due to high stress anisotropy which is more pronounced in case of thicker fluids. It was also observed that in case of vaseline injection, stress anisotropy decreases treatment breakdown pressure. / text

published_or_final_version / Nursing Studies / Master / Master of Nursing

The present study investigated the effects of different goal orientations on motivation after failure. A 2 goals (mastery vs. performance) x 2 regulatory focuses (approach vs. avoidance) experimental design was adopted. Junior secondary students (N = 173) voluntarily attended a prefix learning class. They were randomly assigned one of the four conditions and finished some computerized tasks. The result indicated performance-approach participants had lower persistence than mastery-approach, mastery-avoidant and performance-avoidant participants after failure feedback, regardless of self-efficacy level. Mastery-oriented participants displayed higher interest and higher willingness to seek challenge than performance-oriented participants after failure. Avoidance focus participants revised more materials than approach focus participants after failure. / published_or_final_version / Educational Psychology / Master / Master of Social Sciences

Heart failure is associated with significant morbidity, mortality and economic cost. Over the past 30 years our understanding of the pathophysiology of heart failure has advanced greatly. However, morbidity and mortality remain high and further improvements in therapy are necessary. Pre-clinical data suggest that the novel peptide apelin, acting through the APJ receptor, has anti-hypertensive, vasodilator, diuretic and inotropic actions and an antagonistic relationship with angiotensin-II. These findings are of obvious interest in heart failure, particularly as plasma and myocardial apelin concentrations are reduced in patients with advanced heart failure. Consequently, it is hypothesised that upregulation of the apelin-APJ system may be of therapeutic value. The aims of this doctoral thesis were therefore to delineate the actions, mechanisms of action and relative efficacy of apelin; compare the arterial vasodilator action of apelin in health and heart failure; and examine the interactions of apelin with other key neurohormones in health and heart failure. This was achieved using wire myography and organ bath techniques in an array of animal and human blood vessels and in a validated rabbit model of post-myocardial infarction heart failure. Apelin is a modest nitric oxide and prostanoid dependent vasodilator at supra-physiological concentrations in small arteries. No such effect was noted in larger arteries or veins. This vasodilator action is abolished in heart failure, whilst response to acetylcholine is preserved suggesting an apelin-APJ specific abnormality in this syndrome. Apelin has an antagonistic relationship with endothelin-1 and synergistic relationship with B-type natriuretic peptide in normal small arteries. Again, these putative cardioprotective properties are lost in heart failure. These data suggest that the putative cardioprotective properties of apelin are lost in heart failure.