Thèse de doctorat : SCIENCES APPLIQUEES : Metz : 1994. / 1994METZ031S. 57 REF.

Thesis (Ph.D)--Aerospace Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Dr. Dimitri N. Mavris; Committee Member: Dr. Brian J. German; Committee Member: Dr. Daniel P. Schrage; Committee Member: Dr. Frederic Villeneuve; Committee Member: Dr. Michelle R. Kirby; Committee Member: Ms. Antje Lembcke. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Log processor heads have become increasingly used in New Zealand (NZ) forest harvesting operations to increase productivity and improve worker safety. Information regarding the measurement accuracy and productivity of new model processor heads is limited. As a result, log quality control (QC) is carried out on logs that have been merchandised by a processor head. This task can have a high risk for injury from man – machine interaction. A trend between studies was that older model Waratah’s did not have sufficient measurement accuracy to alleviate the requirement for log QC. In this study, a Waratah HTH 625c processor head operating in NZ was analysed for measurement accuracy and productivity. Measurement accuracy was considered by measuring logs for length, diameter and branch size. A comparison of two methods of processing was also considered to determine measurement accuracy, productivity and production efficiency for the way logs are delimbed and merchandised. Once gathered, the data was then analysed to identify significant effects, trends and relationships between variables. Length measurements were highly accurate but diameter measurements were under- estimated. It was also evident that although there was absolute accuracy, there was a high variability in measurements with underestimating and overestimating. Branch size was also found to have a significant impact in reducing length measurement accuracy and productivity. Single pass processing has significantly higher production efficiency than two pass processing, although single pass processing had a higher length error associated with it. The Waratah HTH 625c processor head has better measurement accuracy than older model Waratah’s. However, logs are still cut out-of-spec which will require a log QC to identify. As measurement technology is further improved in processor heads, and improvements to NZ’s plantation resource (improved form and smaller branching) are realised at harvest age, measurement accuracy and productivity of log processor heads will further improve.

Graphics Processing Units (GPUs) have become a popular platform for executing general purpose (i.e., non-graphics) applications. To run efficiently on a GPU, applications must be parallelized into many threads, each of which performs the same task but operates on different data (i.e., data parallelism). Previous work has shown that some applications experience significant speedup when executed on a GPU instead of a CPU. The applications that benefit most tend to have certain characteristics such as high computational intensity, regular control-flow and memory access patterns, and little to no communication among threads. However, not all parallel applications have these characteristics. Applications with a more balanced compute to memory ratio, divergent control flow, irregular memory accesses, and/or frequent communication (i.e., not-so-regular applications) will not take full advantage of the GPU's resources, resulting in performance far short of what could be delivered. The goal of this dissertation is to enhance the GPU architecture to better handle not-so-regular parallelism. This is accomplished in two parts. First, I analyze a diverse set of data parallel applications that suffer from divergent control-flow and/or significant stall time due to memory. I propose two microarchitectural enhancements to the GPU called the Large Warp Microarchitecture and Two-Level Warp Scheduling to address these problems respectively. When combined, these mechanisms increase performance by 19% on average. Second, I examine one of the most important and fundamental applications in computing: database search. Database search is an excellent example of an application that is rich in parallelism, but rife with not-so-regular characteristics. I propose enhancements to the GPU architecture including new instructions that improve intra-warp thread communication and decision making, and also a row-buffer locality hint bit to better handle the irregular memory access patterns of index-based tree search. These proposals improve performance by 21% for full table scans, and 39% for index-based search. The result of this dissertation is an enhanced GPU architecture that better handles not-so-regular parallelism. This increases the scope of applications that run efficiently on the GPU, making it a more viable platform not only for current parallel workloads such as databases, but also for future and emerging parallel applications. / text

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Syfte: Syftet med denna studie är att identifiera hur framfarten av online-banking påverkar de fysiska kontoren. Metod: Vår studie har genomförts med en kvalitativ metod och en abduktiv ansats. Valet av datainsamlingsmetod  resulterade i semistrukturerade intervjuer. Urvalet för respondenterna har varit litet med bara 9 respondenter. Respondenterna valdes strategiskt och utefter vad som fanns att tillhandahålla. Vi använder både personal på bankkontor och bankkunder. Teoretiskt referensram: Utgångspunkten för vår studie är tidigare genomförd forskning på relaterade ämne. Även beslutsteorier och forskning om hur individer reagerar på förändring har legat till grund för vår studie. Dessutom använder vi oss av teorin diffusion of an innovation. Slutsats: Resultatet av denna studie blev att vi identifierade ett cirkulärt händelseförlopp när det gäller förhållandet mellan online-banking och bankkontor. Utefter analyser av de semistrukturerade intervjuerna kom vi även fram till att de fysiska bankkontoren fortfarande behövs både ur kunders och bankers perspektiv. / Purpose: The purpose with this study is to identify how the online-banking services has a impact on the physical branch offices. Methodology: The research strategy for our study has been of a qualitative nature and with a abductive approach. We have been using semi-structured interviews to collect our empirics. Our selection of respondents is fairly small with only 9 respondents. There has been an strategic selection of respondents. We are using both staff at branch office and banking customers. Theoretical Approach: The base for our study is earlier research on similar subjects. We have also been using decision making theories and proven research about how individuals react on changes. Furthermore, we are using the diffusion of innovation theory. Conclusions: The result of our study is that we identified a circular course of event that describe the relationship between online-banking services and bank offices. The analysis that was made on the semi-structured interviews shows that the branch offices still is desirable both from customers and from banks.

The research reported in this thesis considers the classical combinatorial optimization problem known as the Generalized Assignment Problem (GAP). Since the mid 1970's researchers have been developing solution approaches for this particular type of problem due to its importance both in practical and theoretical terms. Early attempts at solving GAP tended to use exact integer programming techniques such as Branch and Bound. Although these tended to be reasonably successful on small problem instances they struggle to cope with the increase in computational effort required to solve larger instances. The increase in available computing power during the 1980's and 1990's coincided with the development of some highly efficient heuristic approaches such as Tabu Search (TS), Genetic Algorithms (GA) and Simulated Annealing (SA). Heuristic approaches were subsequently developed that were able to obtain high quality solutions to larger and more complex instances of GAP. Most of these heuristic approaches were able to outperform highly sophisticated commercial mathematical programming software since the heuristics tend to be tailored to the problem and therefore exploit its structure. A new approach for solving GAP has been developed during this research that combines the exact Branch and Bound approach and the heuristic strategy of Tabu Search to produce a hybrid algorithm for solving GAP. This approach utilizes the mathematical programming software Xpress-MP as a Branch and Bound solver in order to solve sub-problems that are generated by the Tabu Search guiding heuristic. Tabu Search makes use of memory structures that record information about attributes of solutions visited during the search. This information is used to guide the search and in the case of the hybrid algorithm to generate sub problems to pass to the Branch and Bound solver. The new algorithm has been developed, imp lemented and tested on benchmark test problems that are extremely challenging and a comprehensive report and analysis of the experimentation is reported in this thesis.

We take a novel perspective on real-life decision making problems involving binary activity-selection decisions that compete for scarce resources. The current literature in operations research approaches these problems by forming an optimal portfolio of activities that meets the specified resource constraints. However, often practitioners in industry and government do not take the optimal-portfolio approach. Instead, they form a rank-ordered list of activities and select those that have the highest priority. The academic literature tends to discredit such ranking schemes because they ignore dependencies among the activities. Practitioners, on the other hand, sometimes discredit the optimal-portfolio approach because if the problem parameters change, the set of activities that was once optimal no longer remains optimal. Even worse, the new optimal set of activities may exclude some of the previously optimal activities, which they may have already selected. Our approach takes both viewpoints into account. We rank activities considering both the uncertainty in the problem parameters and the optimal portfolio that will be obtained once the uncertainty is revealed. We use stochastic integer programming as a modeling framework. We develop several mathematical formulations and discuss their relative merits, comparing them theoretically and computationally. We also develop cutting planes for these formulations to improve computation times. To be able to handle larger real-life problem instances, we develop parallel branch-and-price algorithms for a capital budgeting application. Specifically, we construct a column-based reformulation, develop two branching strategies and a tabu search-based primal heuristic, propose two parallelization schemes, and compare these schemes on parallel computing environments using commercial and open-source software. We give applications of prioritization in facility location and capital budgeting problems. In the latter application, we rank maintenance and capital-improvement projects at the South Texas Project Nuclear Operating Company, a two-unit nuclear power plant in Wadsworth, Texas. We compare our approach with several ad hoc ranking schemes similar to those used in practice. / text

Despite its emergence as a key player in igniting policy change, very little work has been done to understand the Supreme Court’s agenda in terms of policy content. Scholars have tended to describe the Court mostly in terms of the direction (liberal/conservative) of justices’ decisions and the significance of particular cases. As a result, I ask if the Supreme Court allocates a disproportionate share of its docket to particular policy areas and if over attention to issue areas can be explained in terms of ideological shifts on the Court. This paper utilizes a new dataset, which includes a sample of 4591 certiorari denied cases and all 7014 cases granted certiorari from 1948 to 1990. Each case is coded for policy content according to the Policy Agendas Project coding scheme. By comparing the policy content of certiorari granted and certiorari denied cases over time, I show that judicial attention to policy areas waxes and wanes and court eras can be differentiated according to which issues occupied a disproportionate share of the Court’s attention. Additionally, I demonstrate that disproportionate attention to a subset of issue areas varies with changes in the ideological makeup of the Court. / text

Ο κύριος σκοπός της παρούσας εργασίας είναι να παρουσιάσει τη μέθοδο του benchmarking και τα περιθώρια εφαρμογής της στον οικονομικό προγραμματισμό πιστωτικών ιδρυμάτων. Η τεχνική που χρησιμοποιούμε για την εφαρμογή της μεθόδου του benchmarking είναι η ανάλυση αριθμοδεικτών. Στην αρχή πραγματοποιούμε μια σύγκριση ανάμεσα στις τιμές συγκεκριμένων αριθμοδεικτών της Εθνικής Τράπεζας της Ελλάδος με τη μέση τιμή των δεικτών αυτών στον τραπεζικό κλάδο. Έπειτα, πραγματοποιούμε μια εφαρμογή του benchmarking ανάμεσα σε υποκαταστήματα της Εθνικής Τράπεζας. Τα αποτελέσματα αυτών των συγκρίσεων μπορούν να χρησιμοποιηθούν στη σύνταξη των προϋπολογισμών επόμενων περιόδων. / The major aim of this study is to present benchmarking, as it is used during the process of financial planning of banking institutions. The technique, which we use to apply the method of benchmarking, is accounting ratio analysis. At first we make a comparison between the price of certain ratios of National Bank of Greece and the average price for the whole banking sector in Greece. Then we present benchmarking between bank branches of the same bank. The output of these comparisons can be used in the financial planning and the budgets of forthcoming periods.