A growing number of studies suggest that accounting information risk, primarily idiosyncratic in nature, can be diversified away in the capital market. In this dissertation, I show that accounting information risk, proxied by accruals quality, is priced even if it is entirely idiosyncratic. In particular, building on a model from the ambiguity literature, I demonstrate that (1) in an under-diversified market, idiosyncratic information risk is priced even if it is diversifiable, and (2) in a well-diversified market, idiosyncratic information risk is priced when information is subject to managers' discretion and thus ambiguous. The empirical results corroborate the predictions from the model. Specifically, although an association is observed between (unambiguous if risky) innate accruals quality and cost of capital, the association can be largely mitigated through diversification. However, diversification has little impact on the association between (ambiguous) discretionary accruals quality and cost of capital. Taken together, these findings strengthen our understanding of the fundamental role of accounting information as a basis for capital allocation.

Musical characterisation plays an important role in Britten's operas. The aim of this study was to determine how Britten depicts the diverse, dualistic characters in Billy Budd through music. Ambiguity, which is characteristic of this opera, is the result of the manner in which the plot is portrayed musically through developing motives. The conflict between the diverse characters in Billy Budd is depicted by the thematic material. The musical ideas and motives change as the plot becomes more complex. The method of investigation was, in the first instance, to analyse the musical ideas associated with each character. Second, the manner in which these ideas change through the course of the opera was pointed out. The story does not only concern itself with the relationship between good and evil. The fate of the three main characters, Billy, Vere and Claggart, is precisely the opposite of their true nature. Who they really are, is not reflected in their doings, as depicted by the integrated themes. Billy, the innocent boy, kills. Vere, the father figure, doesn't protect Billy on the day of his conviction. Claggart, who manipulates to have his own way, can't avoid his own death. This study shows that Billy is represented by the stammer figure and Vere by the "Starry Vere" motive. Vere's inner conflict is depicted by the ambiguous combination of a major third and minor third interval. The confusion that eventually leads to Billy's demise is represented by intervals of a perfect fourth, associated with Claggart. During the course of the opera, Vere's music is infiltrated by Claggart's motives. Billy is represented in the opera by the woodwind instruments, Vere by the strings and Claggart by the brass instruments. / Thesis (M.Mus.)--North-West University, Potchefstroom Campus, 2006.

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Musical characterisation plays an important role in Britten's operas. The aim of this study was to determine how Britten depicts the diverse, dualistic characters in Billy Budd through music. Ambiguity, which is characteristic of this opera, is the result of the manner in which the plot is portrayed musically through developing motives. The conflict between the diverse characters in Billy Budd is depicted by the thematic material. The musical ideas and motives change as the plot becomes more complex. The method of investigation was, in the first instance, to analyse the musical ideas associated with each character. Second, the manner in which these ideas change through the course of the opera was pointed out. The story does not only concern itself with the relationship between good and evil. The fate of the three main characters, Billy, Vere and Claggart, is precisely the opposite of their true nature. Who they really are, is not reflected in their doings, as depicted by the integrated themes. Billy, the innocent boy, kills. Vere, the father figure, doesn't protect Billy on the day of his conviction. Claggart, who manipulates to have his own way, can't avoid his own death. This study shows that Billy is represented by the stammer figure and Vere by the "Starry Vere" motive. Vere's inner conflict is depicted by the ambiguous combination of a major third and minor third interval. The confusion that eventually leads to Billy's demise is represented by intervals of a perfect fourth, associated with Claggart. During the course of the opera, Vere's music is infiltrated by Claggart's motives. Billy is represented in the opera by the woodwind instruments, Vere by the strings and Claggart by the brass instruments. / Thesis (M.Mus.)--North-West University, Potchefstroom Campus, 2006.

Detecting ambiguity is essential for successful communication. Two studies investigated whether preschool- (4- to 5-year-old) and school-age (6- to 7-year-old) children show sensitivity to communicative ambiguity and can use this cue to determine which speakers constitute valuable informational sources. Children were provided clues to the location of hidden dots by speakers who varied in clarity and accuracy. Subsequently, children decided from whom they would like to receive additional information. In Study 1, preschool- (n=40) and school-age (n=42) children preferred to solicit information from unambiguous than from ambiguous speakers. However, ambiguous speakers were preferred to speakers who provided inaccurate information. In Study 2, when not provided with information about the outcome of the speakers’ clues, school-age (n=22), but not preschool-age (n=19), children preferred unambiguous relative to ambiguous speakers. Results highlight a developmental progression in children’s use of communicative ambiguity as a cue to determining which individuals are preferable informants.

This thesis is concerned with (i) how to estimate the perceived mortality risk, (ii) how to calculate the welfare change of mortality risk reduction and (iii) whether ambiguity aversion influences subjects' treatment decision. This study is an important topic in environmental and resource economics, and the attempt to introduce ambiguity preference into the models might shed light on future research in nonmarket valuation. In this study, I estimate the economic value of reducing mortality risk relating to arsenic in drinking water employing contingent valuation in U.S. arsenic hot spots. Re-cent studies have shown that perceived risk is a more reliable variable than scientific assessments of risk when applied to interpret and predict individual's averting behavior. I am also interested in the confidence level of perceived risk, which was elicited and treated as the degree of risk ambiguity in this paper. I develop a formal parametric model to calculate the mean willingness to pay (WTP) for mortality risk reduction, and find weak evidence of ambiguity aversion.

Satellite-based navigation systems make it possible to determine the relative positions of points on the earth with centimetre or even millimetre level accuracy over baselines of up to several thousand kilometres. The highest possible accuracy can only be achieved if the carrier phase integer ambiguities can be resolved. In order to resolve the L1 and L2 integer ambiguities over long GPS baselines, the double difference residual ionospheric errors must be estimated for every satellite, every epoch. The resulting number of parameters is usually too large for estimation using ordinary least squares to be practical due to the time or computing resources needed for the processing. The technique currently used to efficiently estimate the parameters is known as pre-elimination. Pre-elimination divides the unknowns into parameters of interest (the coordinates and ambiguities) and nuisance parameters (the ionospheric path delays). The nuisance parameters are treated as stochastic variables and modelled as process noise, avoiding the need for them to be explicitly estimated. Whilst this approach is highly efficient, it makes assumptions about the stochastic behaviour of the residual ionospheric error that are not necessarily valid. The effectiveness of preelimination can be increased through the use of a deterministic model of the ionosphere. It is the hypothesis of this research that the ionospheric error can be more effectively estimated than is possible with pre-elimination, leading to more reliable ambiguity resolution for long baseline precise positioning. (For complete abstract open document)

The role of the basal ganglia in human language function remains unknown, despite a corpus of literature documenting the association between vascular lesions of the dominant nonthalamic subcortical (NS) region and disordered language. Theories of subcortical language function have been postulated (e.g., Crosson, 1985; Wallesch & Papagno, 1988), however, research in this field has remained largely data-driven, providing limited descriptions of individuals with vascular NS lesions in terms of performance on standard off-line language measures. This approach has failed to reveal the underlying nature of these language deficits “locally” in terms of various dynamic and temporally constrained linguistic and nonlinguistic component processes. The current series of studies are based largely on the premise that such empirical data has the potential to speak more directly to the cogency of current theories proposing a subcortical role in language or related cognitive functions. The present thesis investigated the performance of individuals with dominant chronic vascular NS lesions, compared to matched control subjects, individuals with Parkinson’s disease (PD) (also assumed to have NS dysfunction) and subjects with cortical lesions (CL), on a series of experiments which allowed for the real-time examination of language processing, manipulating the degree to which automatic and attentional/strategic processing is invoked. The theoretical underpinning of these experiments hinges primarily on the proposed role of frontal-subcortical systems in mediating aspects of language via attentional/strategic mechanisms. Accordingly, it was hypothesised that the locus of impairment for individuals with NS lesions would be centred selectively on those facets of language processing which require increased recourse to these proposed frontal-subcortical cognitive capacities. The language abilities of 15 subjects with chronic dominant NS lesions, 15 matched control subjects, 14 matched subjects with CL, and 12 matched individuals with PD were examined initially on the Western Aphasia Battery (WAB) and the Boston Naming Test (BNT). Most NS subjects were classified as non-aphasic according to the WAB, however, circumscribed deficits were evidenced, typically in generative and confrontation naming. In contrast, the CL group showed significant deficits on most aspects of the WAB compared to matched normal control subjects, and presented with a more severe impairment than NS subjects overall on the WAB and in confrontation naming and repetition. The PD group performance was not significantly different from the matched control group, while PD subjects performed better than the NS group overall on the WAB. The same cohort of NS, CL, PD, and control subjects undertook a battery of complex language measures designed to place a range of higher-order cognitive demands on the language processing system. This battery included subtests from the Test of Language Competence-Expanded Edition (TLC-E), the Test of Word Knowledge (TOWK), and The Word Test-Revised (TWT-R). The NS, CL, and PD subjects presented with marked disturbances in those tasks involving cognitive-linguistic flexibility, sentence formulation, indeterminacy of meaning, and metalinguistic manipulation of the lexical-semantic system. Collectively, the off-line results suggest that those aspects of language processing which are more heavily reliant on higher-order cognitive capacities are selectively compromised in subjects with NS lesions and PD. This assumption was further examined and substantiated in a series of on-line lexical ambiguity priming experiments performed by a subset of the original NS subjects (n = 10), matched control subjects (n = 10), matched CL subjects (n=10), and matched PD subjects (n = 10). When lexical ambiguities were presented in a single word context as word triplets, NS subjects showed rapid nonselective lexical activation, suggesting that intact lexical-semantic information could be accessed via automatic routines, similar to control subjects. Unlike control subjects, however, NS subjects were unable to sustain any form of significant activation, implying a selective impairment in the ability to manipulate lexical-semantic information through attentional/controlled processing. This breakdown was qualitatively different to the controlled processing disturbance evidenced by CL subjects, who maintained nonselective meaning facilitation over time, while PD subjects showed a pattern of selective priming consistent with a reduction in attentional processing. The emerging picture of a dissociation between intact automatic processing and compromised attentional/strategic lexical processing in the NS subjects was further elucidated in an experiment examining the processing of unequibiased lexical ambiguities in isolation. In this study, NS and PD subjects showed rapid nonselective meaning facilitation, again implying intact automatic lexical processing. While control and CL subjects evidenced multiple meaning activation followed by selective facilitation of the dominant meaning, NS and PD subjects were unable to achieve selective meaning facilitation, instead showing a protracted period of nonselective lexical activation. This finding suggested that when ambiguities were encountered in isolation, there was not an absolute breakdown in attentional processing per se, but rather a circumscribed deficit in the selective attentional engagement of the semantic network on the basis of meaning frequency, possibly implicating a disturbance of inhibitory mechanisms within the semantic network. A cross-modal priming experiment was used to investigate how lexical ambiguities were processed and resolved in a biased sentential context. Initially, lexical activation for the neurological patient groups appeared influenced by contextual information to a greater extent than in normal controls, which may indicate delayed lexical decision making or disturbed automatic lexical access. Only the PD and NS individuals failed to then maintain selective facilitation of the contextually appropriate meaning, suggesting a breakdown in the attention-based control and maintenance of semantic activation on the basis of integrated sentential constraints. This finding was extended in another cross-modal priming experiment, where NS and PD subjects appeared unable to use discourse-level information to select meanings and develop topical inferences via attentional/strategic mechanisms, while CL subjects showed a selective disturbance of inference development. The results of this thesis have served to delineate certain dynamic aspects of language processing in individuals with NS lesions in terms of automatic lexical processing components and processes involving the attentional/strategic selection of meaning on the basis of meaning frequency and various types of contextual information. In general, the NS group showed a demarcation between intact automatic processing and a breakdown in attentional/strategic processing which was manifest differently depending on the conditions under which processing was invoked. Furthermore, the performance of NS subjects on attentional operations was able to be dissociated under certain conditions from CL group performance and was similar to the PD group’s performance in certain instances. These preliminary findings are consistent with recent theories proposing a role for frontal-subcortical systems in the “top-down” modulation of semantic processing via executive attentional and strategic mechanisms. Although a disturbance in these systems provides a parsimonious explanation of the NS and PD group performance, such conclusions are drawn tentatively with the caveat that the precise neuropathological basis of cognitive-linguistic deficits in these individuals remains unclear at present.

Thesis (M.A.)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

Thesis (M.A)--University of Texas at El Paso, 2008. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.