This project examines the determinants of political responsiveness to bureaucratic performance. A large literature exists that has examined how bureaucratic agencies are responsive to political institutions. While policy theory contends that the reverse is also true – that is, political institutions engage in political assessment of policies – there is little empirical literature examining this important question. Indeed, research in public administration suggests that political responsiveness only occurs following massive bureaucratic failure or policy crises. Using data from Texas public school districts, this dissertation explores the role of policy salience in determining the likelihood of political responsiveness to bureaucratic outputs and outcomes. The findings suggest that issue salience is the key determinant of political involvement in administration. Furthermore, this project incorporates the concepts of descriptive and substantive representation in examining these questions. The results indicate that policy salience depends on the composition of the interests of political institutions. Furthermore, race and ethnicity work to shape those preferences and, in turn, condition what policy makers deem as salient. The findings suggest that descriptively unrepresentative political institutions are less likely to be responsive to the needs of those who are not represented (e.g. Latino students). Thus, representation is central to political responsiveness when the policy outputs or outcomes in question are not universally salient. Finally, this project examines whether political institutions can influence policy outcomes, and, more importantly, what factors – environmental, organizational, managerial – either facilitate or constrain the political influence of elected officials. The findings suggest that goal and preference alignment between political institutions and bureaucratic agencies is critical in enhancing political influence – a finding that is commonly argued in formal models of political control, but rarely tested empirically. This research also finds that bureaucratic power or independence can work to hinder political influence of policy outputs.

Geometric computations are essential in many real-world problems. One important issue in geometric computations is that the geometric models in these problems can be so large that computations on them have infeasible storage or computation time requirements. Decomposition is a technique commonly used to partition complex models into simpler components. Whereas decomposition into convex components results in pieces that are easy to process, such decompositions can be costly to construct and can result in representations with an unmanageable number of components. In this work, we have developed an approximate technique, called Approximate Convex Decomposition (ACD), which decomposes a given polygon or polyhedron into "approximately convex" pieces that may provide similar benefits as convex components, while the resulting decomposition is both significantly smaller (typically by orders of magnitude) and can be computed more efficently. Indeed, for many applications, an ACD can represent the important structural features of the model more accurately by providing a mechanism for ignoring less significant features, such as wrinkles and surface texture. Our study of a wide range of applications shows that in addition to providing computational efficiency, ACD also provides natural multi-resolution or hierarchical representations. In this dissertation, we provide some examples of ACD's many potential applications, such as particle simulation, mesh generation, motion planning, and skeleton extraction.

Executing sequential code in parallel on a multithreaded machine has been an elusive goal of the academic and industrial research communities for many years. It has recently become more important due to the widespread introduction of multicores in PCs. Automatic multithreading has not been achieved because classic, static compiler analysis was not powerful enough and program behavior was found to be, in many cases, input dependent. Speculative thread level parallelization was a welcome avenue for advancing parallelization coverage but its performance was not always optimal due to the sometimes unnecessary overhead of checking every dynamic memory reference. In this dissertation we introduce a novel analysis technique, Hybrid Analysis, which unifies static and dynamic memory reference techniques into a seamless compiler framework which extracts almost maximum available parallelism from scientific codes and incurs close to the minimum necessary run time overhead. We present how to extract maximum information from the quantities that could not be sufficiently analyzed through static compiler methods, and how to generate sufficient conditions which, when evaluated dynamically, can validate optimizations. Our techniques have been fully implemented in the Polaris compiler and resulted in whole program speedups on a large number of industry standard benchmark applications.

Meaning based search retrieves objects from search index repository based on user's search Meanings and meaning of objects rather than keyword matching. It requires techniques to capture user's search Meanings and meanings of objects, transform them to a representation that can be stored and compared efficiently on computers. Meaning of objects can be adequately captured in terms of a hierarchical composition structure called concept tree. This thesis describes the design and development of an algorithm that transforms the hierarchical concept tree to a tensor representation using tensor algebra theory. These tensor representations can capture the information need of a user in a better way and can be used for similarity comparisons in meaning based search. A preliminary evaluation showed that the proposed framework outperforms the TF-IDF vector model in 95% of the cases and vector based conceptual search model in 92% of the cases in adequately comparing meaning of objects. The tensor conversion tool also was used to verify the salient properties of the meaning comparison framework. The results show that the salient properties are consistent with the tensor similarity values of the meaning comparison framework.

The primary intent of this study was to gain insight into children's ability to use visual information in planning reaching movements. More specifically, the work presented here examined, from a developmental perspective, the use of visual information to use a) egocentric cues, b) allocentric cues, and c) the combination, in the form of visual background around a target. Children representing the age groups 5-, 7-, 9-, 11 years and adults participated in three experiments. All experiments were conducted using an immediate (visually-guided) and response-delay (memory-guided) paradigm. Experiment 1 examined the ability of participants to use an egocentric frame of reference to estimate reach via motor imagery. Results indicated that introducing a >̲ 2s delay affected responses in all age groups, especially the younger age groups (5- and 7-year-olds). As delay increased, children as a group tended to overestimate, while adults underestimated. Experiment 2 investigated how participants used allocentric cues to estimate the location of objects in a perceptual estimate paradigm. Results revealed that introducing a delay affected the estimation of distance among all age groups, with greater effect on the younger age groups. Experiment 3 examined how a visual background surrounding a target would affect estimation of reach. Results revealed that there were no differences when targets were surrounded with or without a background. Results also showed that the 5- and 7-year-olds were most affected on their perception of reach and estimates by longer delays. Considered together, these results hint that: (1) there is a significant temporal constraint on the representation of movement through the visoumotor stream, especially with children 7 years and younger, and (2) children as a whole tend to operate and rely more on an egocentric frame of reference; therefore, responses of reachability and distance estimates were susceptible to greater error when performed after a 2s delay.

We construct a new operation among representations of the symmetric group that interpolates between the classical internal and external products, which are defined in terms of tensor product and induction of representations. Following Malvenuto and Reutenauer, we pass from symmetric functions to non-commutative symmetric functions and from there to the algebra of permutations in order to relate the internal and external products to the composition and convolution of linear endomorphisms of the tensor algebra. The new product we construct corresponds to the Heisenberg product of endomorphisms of the tensor algebra. For symmetric functions, the Heisenberg product is given by a construction which combines induction and restriction of representations. For non-commutative symmetric functions, the structure constants of the Heisenberg product are given by an explicit combinatorial rule which extends a well-known result of Garsia, Remmel, Reutenauer, and Solomon for the descent algebra. We describe the dual operation among quasi-symmetric functions in terms of alphabets.

The aim of this study is to analyze students¡¦ mathematics concepts in solving Pythagorean Theorem problems presented in two different representations (word problems and word problems with diagrams). The investigators employed the mathematics competence indicators in Grade 1-9 Integrated Curriculum in developing such problems. In analyzing data, the investigator used Schoenfeld¡¦s method in depicting their problem-solving processes, with attention to students¡¦ sequence and difference in time consumption. Four eight grade students with good competence in mathematics and expressions from a secondary school were selected as research subjects. Problems related to Pythagorean Theorem were divided into three types: Shape, Area, and Number. Data were collected using thinking aloud method and semi-structured interview, and triangulation was further applied in protocol analysis. The research results revealed 3 findings: (1) For the ¡§Shape¡¨ type problems, students¡¦ problem-solving concepts varied with different problem representation. For the ¡§Area¡¨ and ¡§Number¡¨ types of problems (without diagram), students were required to use their geometric concept when processing word problems. Students¡¨ use of problem-solving concepts would not significantly vary with problem representation types. However, students¡¦ use of problem-solving methods would affect the types and priorities of concepts used. Generally, the types of mathematics concepts could be made up by the frequency of concepts used, and more types of problem-solving concepts would be used for word problems representation than for word problems with diagrams representation. (2) In terms of the time consumed in the first three problem-solving stages of Schoenfeld, the time required to solve word problems was 1.6 times of that required to solve word problems with diagrams. In terms of the total time consumed, the time required to solve word problems was 1.25 times of that required to solve word problems with diagrams. In the problem-solving stages, students needed to explore the problem first when dealing with word problems before they could go on to solve the problem, and such repetition was more frequent when they dealt with word problems. (3) For both type of problem representations, there is a higher number of correctly-answered problems. This finding indicated that a higher frequency of problem-solving concepts and less repetition in the problem-solving stage were required; and vice versa. As to the sequence of Pythagorean Theorem concepts to be taught, the investigator suggest teachers to start with the concept of area filling in the ¡§Shape¡¨ type of problems to derive Pythagorean Theorem, and further apply the formula to - III - solving ¡§Number¡¨ problems. After students have acquired basic competency in ¡§Shape¡¨ and ¡§Number¡¨ Pythagorean Theorem problems, teachers could explain and introduce this theorem from the perspective of ¡§Area¡¨. Finally, in problem posing, teachers were also advised to apply various contexts; covering all kinds of representations of problems that enhance students¡¦ utilization of mathematics concepts; and to cater for various needs of students.

Thesis (MA)--University of Montana, 2009. / Contents viewed on November 29, 2009. Title from author supplied metadata. Includes bibliographical references.

Thesis (Ph. D.)--University of California, San Diego, 2002. / Vita. Includes bibliographical references (leaves 224-229).

Thesis (Ph. D.)--Open University. BLDSC no. DX222333.