Thesis (Ph. D.)--University of Chicago, Dept. of Statistics, December 2003. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--Oregon Graduate Center, 1987.

Extant attention theories explain how individuals direct attention towards different stimuli. However, the theories are relatively silent about how attention is switched off, other than the idea that attention to a stimulus may cease because another stimulus overwhelms the first in its demand for attention. We theorized that individuals have a tendency to ‘not switch off’ attention from a current process, in the absence of a competing stimulus that wrenches attention away from it. We present evidence consistent with this attentional bias – individuals continue attending to an ongoing mundane process until it reaches its ‘end’, even when that attention is normatively unwarranted, namely under conditions where (1) they cannot control or influence the process and (2) they are aware of the outcome with a reasonable degree of certainty as well. Moreover, since attention is a limited capacity resource, such attentional hijacking is negatively hedonically marked which gets mis-attributed to salient available targets. Consequently, we also demonstrate decreased positivity in attitudes towards entities associated with the incomplete process.

The aim of this thesis is to study the role played by negation in databases and to develop data models that can handle inconsistent and incomplete information. We develop models that also allow incompleteness through disjunctive information under both the CWA and the OWA in relational databases. In the area of logic programming, extended logic programs allow explicit representation of negative information. As a result, a number of extended logic programs have an inconsistent semantics. We present a translation of extended logic programs to normal logic programs that is more tolerant to inconsistencies. Extended logic programs have also been used widely in order to compute the repairs of an inconsistent database. We present some preliminary ideas on how source information can be incorporated into the repair program in order to produce a subset of the set of all repairs based on a preference for certain sources over others.

The notion of fulfilment of a formula by a sequence of numbers, an approximation of truth due to Kripke, is presented and subsequently formalised in the weak arithmetic theory IΣ1, in some detail. After a number of technical results connecting the formalised notion to the meta-theoretical one a version of Gödel’s Incompleteness Theorem, that no consistent, recursively axiomatisable, Σ2-sound extension T of Peano arithmetic is complete, is shown by construction of a true Π2-sentence and a model of T where it is false, yielding its independence from T. These results are then generalised to a more general notion of fulfilment, proving that IΣ1 has no complete, consistent, recursively axiomatisable, Σ2-sound extensions by a similar construction of an independent sentence. This generalisation comes at the cost of some naturality, however, and an explicit falsifying model will only be obtained under additional assumptions. The aim of the thesis is to reproduce in some detail the notions and results developed by Kripke and Quinsey and presented by Quinsey and Putnam. In particular no novel results are obtained.

abstract: As the information available to lay users through autonomous data sources continues to increase, mediators become important to ensure that the wealth of information available is tapped effectively. A key challenge that these information mediators need to handle is the varying levels of incompleteness in the underlying databases in terms of missing attribute values. Existing approaches such as Query Processing over Incomplete Autonomous Databases (QPIAD) aim to mine and use Approximate Functional Dependencies (AFDs) to predict and retrieve relevant incomplete tuples. These approaches make independence assumptions about missing values--which critically hobbles their performance when there are tuples containing missing values for multiple correlated attributes. In this thesis, I present a principled probabilis- tic alternative that views an incomplete tuple as defining a distribution over the complete tuples that it stands for. I learn this distribution in terms of Bayes networks. My approach involves min- ing/"learning" Bayes networks from a sample of the database, and using it do both imputation (predict a missing value) and query rewriting (retrieve relevant results with incompleteness on the query-constrained attributes, when the data sources are autonomous). I present empirical studies to demonstrate that (i) at higher levels of incompleteness, when multiple attribute values are missing, Bayes networks do provide a significantly higher classification accuracy and (ii) the relevant possible answers retrieved by the queries reformulated using Bayes networks provide higher precision and recall than AFDs while keeping query processing costs manageable. / Dissertation/Thesis / M.S. Computer Science 2011

abstract: Current work in planning assumes that user preferences and/or domain dynamics are completely specified in advance, and aims to search for a single solution plan to satisfy these. In many real world scenarios, however, providing a complete specification of user preferences and domain dynamics becomes a time-consuming and error-prone task. More often than not, a user may provide no knowledge or at best partial knowledge of her preferences with respect to a desired plan. Similarly, a domain writer may only be able to determine certain parts, not all, of the model of some actions in a domain. Such modeling issues requires new concepts on what a solution should be, and novel techniques in solving the problem. When user preferences are incomplete, rather than presenting a single plan, the planner must instead provide a set of plans containing one or more plans that are similar to the one that the user prefers. This research first proposes the usage of different measures to capture the quality of such plan sets. These are domain-independent distance measures based on plan elements if no knowledge of the user preferences is given, or the Integrated Preference Function measure in case incomplete knowledge of such preferences is provided. It then investigates various heuristic approaches to generate plan sets in accordance with these measures, and presents empirical results demonstrating the promise of the methods. The second part of this research addresses planning problems with incomplete domain models, specifically those annotated with possible preconditions and effects of actions. It formalizes the notion of plan robustness capturing the probability of success for plans during execution. A method of assessing plan robustness based on the weighted model counting approach is proposed. Two approaches for synthesizing robust plans are introduced. The first one compiles the robust plan synthesis problems to the conformant probabilistic planning problems. The second approximates the robustness measure with lower and upper bounds, incorporating them into a stochastic local search for estimating distance heuristic to a goal state. The resulting planner outperforms a state-of-the-art planner that can handle incomplete domain models in both plan quality and planning time. / Dissertation/Thesis / Ph.D. Computer Science 2014

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No / This paper shows that the presence of persistent uninsurable risk concentrated in economic depressions has the potential to resolve two well¿known asset pricing puzzles. It is also shown that the presence of such risk in more normal economic expansions and recessions is likely to be much less relevant in determining equilibrium asset prices.

The master’s thesis «“Poem Without a Hero” by Anna Akhmatova: Poetics of Inkompleteness» makes an attempt to investigate one of the main works of A. Akhmatova’s late period from the perspective of the phenomenon of incompleteness. The logic of studying is determined by two important aspects of the phenomenon – aesthetic and ontological. The first chapter is devoted to the theoretical grounds for the incompleteness. Some peculiarities of the verse ordonnance are considered in the second chapter. The specificity of the creative mind expressed in the fundamental text categories such as subjectival and spatiotemporal ordonnances is considered in the third chapter. Generally the master’s thesis is the basis for distinguishing some general principles of inkompleteness. These principles seem to be concerned with the «Poem Without a Hero» creative history. / В магистерской диссертации «“Поэма без героя” Анны Ахматовой: поэтика незавершенного» предпринимается попытка исследовать одно из главных произведений позднего творчества А. Ахматовой с позиции феномена незавершенного, выделение двух важнейших аспектов которого – эстетического и онтологического – обусловливает и логику работы. Первая глава посвящена обоснованию явления незавершенности, в том числе, разграничению понятий завершенное/незавершенное и законченное/незаконченное произведение; во второй главе рассмотрены некоторые особенности стиховой организации «Поэмы», в том числе специфика варьирования строфы; в третьей главе рассматривается специфика художественного сознания, явленная в таких текстообразующих категориях, как субъектная и пространственно-временная организации. В целом диссертация служит основанием для выделения нескольких принципов незавершенности, с которыми, как представляется, связана творческая история «Поэмы без героя».