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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
531

On Integrating Theories of International Economics in the Strategic Planning of Global Supply Chains and Dynamic Supply Chain Reconfiguration with Capacity Expansion and Contraction

Lee, Chaehwa 2011 December 1900 (has links)
This dissertation discusses two independent topics. The first part of the dissertation relates three theories of international economics (comparative advantage, competitive advantage, and competitiveness), and formulates the thesis that incorporating them in the form of readily available individual competitiveness indicators in OR/MS models offers promise to enhance decision-support for the strategic planning of global supply chains in general, and for locating facilities in particular. The objectives of this research were to relate each of these theories and to describe their interrelationships; to describe measures provided by two well-known annual competitiveness reports; and to illustrate application of the theories as a means of supporting the thesis of the research, and justifying the research questions we pose for future research. While this research discusses topics relative to the broader background of global supply chain design, it illustrates applications associated with facility location, a component of the global supply chain design. In the last chapter of the first part of the dissertation, we provide a vision to foster future research that will enhance the profitability of international enterprises under NAFTA. The second part of the dissertation deals with the DSCR model with capacity expansion and contraction. The strategic dynamic supply chain reconfiguration (DSCR) problem is to prescribe the location and capacity of each facility, select links used for transportation, and plan material flows through the supply chain, including production, inventory, backorder, and outsourcing levels. The objective is to minimize total cost. The configuration must be dynamically redesigned over time to accommodate changing trends in demand and/or costs by opening facilities, expanding and/or contracting their capacities, and closing facilities. The problem involves a multi-period, multi-product, multi-echelon supply chain. Research objectives are alternative formulations of DSCR and tests that identify the computational characteristics of each model to determine if one offers superior solvability in comparison with the others. To achieve the first objective, we present an initial MIP model, a refined model that relates decision variables according to a convenient structure, and branch and price (B&P) schemes for the refined model. We found that the network-based formulation offered superior solvability compared to the traditional formulation.
532

The early development, design, and construction of the Marion Branch of the National Home for Disabled Volunteer Soldiers

Rector, Matthew D. January 2002 (has links)
This study has presented a history of the early development, design, and construction of the Marion, Indiana Branch of the National Home for Disabled Volunteer Soldiers. A general history of the institution of the National Home for Disabled Volunteer Soldiers provides the context for the establishment of the Marion Home. A historical review of the selection of the Marion site, its layout plan, design and construction of buildings, and landscape design between 1888 and 1900 was then provided. The development of the Marion Home is next compared with the 1890's developmental history of the Central Branch in Dayton, Ohio and the first ten years of the Danville, Illinois Branch in order to assess commonalities and differences in construction among three homes during the same period. In the conclusion, the evidence suggests that the layout and architectural design of three homes had many similarities during the 1890s and the turn of twentieth century. / Department of Architecture
533

Representation operators of metric and Euclidian charges

Bouafia, Philippe 07 January 2014 (has links) (PDF)
We study multiple valued functions with values in a Hilbert space. We introduce a possibledefinition of Sobolev spaces and the rightful notion of p energy. We prove the existence of pminimizers. Then we consider two-valued real functions of two variables which are stationarywith respect to both domain and range transformations. We prove their local Lipschitzcontinuity and use it to establish strong convergence in W1,2 to their unique blow-up at anypoint. We claim that the branch set of any such function consists of finitely many real analyticcurves meeting at nod points with equal angles. We also provide an example showing thatstationarity with respect to domain transformations only does not imply continuity.In a second part, we prove that there does not exist a uniformly continuous retractionfrom the space of continuous vector fields onto the subspace of vector fields whose divergencevanishes in the distributional sense. We then generalise this result using the concept of mcharges on any subset X _ Rn satisfying a mild geometric condition, there is no uniformlycontinuous representation operator for mcharges in X.
534

Geochemistry and Noble Gases of Permafrost Groundwater and Ground Ice in Yukon and the Northwest Territories, Canada

Utting, Nicholas C. 11 January 2012 (has links)
In Canada’s western Arctic, perennial discharge from permafrost watersheds is the surface manifestation of active groundwater flow systems, yet understanding the mechanisms of groundwater recharge and flow in periglacial environments remains enigmatic. This thesis addresses questions on how and where groundwater recharge occurs. Watersheds were selected in Yukon (Fishing Branch River at Bear Cave Mountain) and the Northwest Territories at latitudes spanning from continuous to discontinuous permafrost (five tributary rivers to the Mackenzie River from Wrigley to Aklavik). All are characterized by perennial flow with open water in the winter, and discharge from sedimentary formations of karstic carbonates and evaporate rocks. Determinations of groundwater contributions to discharge, mixing, recharge conditions and circulation times were made on the basis of a suite of analytical approaches involving measurements of major dissolved ions, δ18O, δD, δ13CDIC, 3H, noble gases and flow gauging was conducted at some sites. The application of these tracers show that hydrogeological conditions and flow paths in permafrost terrains are surprisingly similar to those of temperate regions. Groundwater recharge was determined to be a mix of annual precipitation with contributions from snowmelt and precipitation. All systems investigated show that groundwaters have recharged through organic soils with elevated PCO2, which suggests that recharge occurs largely during summer when biological activity is high. Noble gas concentrations show that the recharge temperature was between 0 and 6 °C, which, when considered in the context of discharge temperatures, suggests that there is no significant imbalance of energy flux into the subsurface. Groundwater ages were found using the 3H-3He method and were dependent on flow path. By characterizing groundwater and surface water chemistry, the proportion of groundwater was found in numerous water courses. The possible impact of ground ice formation and melting on noble gas concentrations in groundwater was considered. To assess this link, a new method to measure the noble gas composition of ground ice bodies was developed. The method can be used to determine the origin of ice, based on changes in noble gas ratios between ice originating from compaction of snow (e.g. glacier ice) vs. ice originating from freezing of water. No significant fractionation of noble gases during groundwater freezing and ground ice formation was identified. Applied to determination of the origin of ground ice bodies, the method was shown to be both diagnostic of ice origin and un-encumbered by reactivity in the subsurface, which compromises the use of the dominant atmospheric gases (O2 and N2).   Résumé Dans l’Ouest de l'Arctique canadien, la décharge pérenne dans certaines rivières en région de pergélisol est la manifestation en surface d’une circulation d’eau souterraine; cependant la compréhension des mécanismes d’écoulement et de recharge des eaux souterraines en région de pergélisol demeure énigmatique. Cette thèse s’intéresse à la question de savoir comment et où la recharge des eaux souterraines se produit. Des bassins versants ont été choisis au Yukon (Rivière Fishing Branch à Bear Cave Mountain) et dans les Territoire du Nord-Ouest à des latitudes s’étendant du pergélisol discontinu au pergélisol continu (cinq tributaires du Mackenzie entre Wrigley et Aklavik). Toutes ces rivières ont un écoulement d’eau pérenne avec des zones non gelées et une décharge dans des formations sédimentaires de roches carbonatées et d‘évaporites. L’identification des contributions des eaux à la décharge, les mélanges, les conditions de recharge, et les temps de circulation ont été faits à partir d’analyses qui ont inclus les concentrations en éléments majeurs, leur valeur isotopique (δ18O, δD, δ13C, 3H), ainsi que leur teneur en gaz rares. A certain des sites analysés des mesures d’écoulement ont été prises. L’application de ces traceurs montre que les conditions hydrauliques et le chemin des écoulements en région de pergélisol sont similaires à ceux des régions tempérées. La recharge en eau souterraine a été identifiée comme étant un mélange de précipitations annuelles, avec des contributions de neige et de pluies. Tous les systèmes étudiés montrent que les eaux souterraines se sont rechargées en traversant des sols organiques avec une PCO2 élevée, ce qui suggère que la recharge se produire largement durant l’été quand l’activité biologique est élevée. Cependant, les concentrations en gaz nobles montre que la température de recharge des eaux souterraines était entre 0 et 6 °C ce qui indique qu’il n’y a pas de déséquilibre de flux d’énergie à l’intérieur de la zone proche de la surface. L’âge des eaux a été déterminé par la méthode 3H-3He et cet âge est dépendant du chemin d'écoulement. En caractérisant les paramètres chimiques des eaux de surface et des eaux souterraines, il a été possible de trouver la contribution des eaux souterraines aux eaux surface. Le possible impact de la formation et de la fonte de la glace souterraine sur les concentrations des gaz nobles a été considéré. Pour déterminer s’il y a un lien entre ceux-ci, une nouvelle méthode pour mesurer la concentration en gaz nobles dans les glaces souterraines a été développée. La méthode peut être utilisée pour déterminer l’origine de la glace; elle est basée sur les changements dans les rapports des gaz nobles entre la glace issue de la compaction de la neige (c’est-à-dire la glace de glacier) par opposition à la glace issue du gel de l’eau. Aucun fractionnement significatif des gaz nobles durant l’engel des eaux souterraines et la formation de glaces souterraines n’a été identifié. Appliquée à l’identification de l’origine des masses de glace enfouies, on a montré que la méthode pouvait permettre d’identifier l’origine des glaces souterraines sans qu’elle soit affectée par des réactions biologiques de sub-surface, lesquelles rendent inutilisables les gaz atmosphériques (O2, and N2).
535

Assembly Line Balancing With Task Paralleling

Kaplan, Ozlem 01 September 2003 (has links) (PDF)
In this study, we consider single model deterministic Assembly Line Balancing problem with task paralleling. The objective is to minimize the total cost which is composed of station opening cost and task dependent equipment cost. A branch and bound algorithm that allows two-level task paralleling is proposed. A heuristic algorithm is also developed both for obtaining efficient upper bounds to branch and bound and for achieving good approximate solutions for large sized problems. Computational experiments are conducted to investigate the effects of experimental parameters on the cost-related and algorithm-related performance measures. The exact algorithm results are compared to the proposed heuristic algorithm results, station paralleling results and optimal solutions without paralleling.
536

Kinetic Analysis Of Glucose-6-phosphate Branch Point In Saccharomyces Cerevisiae

Alagoz, Eda 01 October 2005 (has links) (PDF)
Glycolysis is the main metabolic route in Saccharomyces cerevisiae and it is the sequence of enzyme catalyzed reactions that oxidatively convert glucose to pyruvic acid in the yeast cytoplasm. In addition to the basic steps, glycolysis involves branch points providing the intermediary building blocks of the cell (i.e amino acids and nucleotides). One of these pathways is glucose-6-phosphate branch point which is a junction of glycolytic pathway and pentose phosphate pathway. At this point glucose-6-phosphate can be converted to fructose-6-phosphate a metabolite of glycolytic pathway by phosphoglucoisomerase or it can be dehydrogenated to 6-phosphogluconolactone by glucose-6-phosphate dehydrogenase which is the first enzyme of the pentose phosphate pathway. In this study, the influence of different nitrogen sources on the flux distribution through the pentose phosphate pathway and glycolysis in Saccharomyces cerevisiae was examined. For this purpose, four different compositions of nitrogen sources were used in growth media. The growth medium contained one of the following composition of nitrogen sources / only ammonium sulfate, only yeast nitrogen base, ammonium sulfate and histidine, yeast nitrogen base and histidine. Histidine was added because its synthesis branches from pentose phosphate pathway. In order to analyse the effect of the different compositions of nitrogen sources on the physiology of the yeast, specific activities of hexokinase, phosphoglucose isomerase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase enzymes were measured in the crude extracts of the biomass samples taken in the late exponential phase of the cultures. Addition of histidine caused an increase in the specific activities of all the enzymes analysed in medium containing ammonium sulfate. The specific activity of hexokinase, phosphoglucose isomerase and glucose-6-phosphate dehydrogenase in medium containing yeast nitrogen base and histidine were higher than medium containing yeast nitrogen base. However, the specific activity of 6-phosphogluconate dehydrogenase decreased 3.1% in medium containing yeast nitrogen base and histidine medium with respect to medium with only yeast nitrogen base. The OD value and dry weight in the culture containing histidine aminoacid was higher than the cultures contaning only ammonium sulfate and only yeast nitrogen base. Also the period of the exponential phase was shorter in medium containing ammonium sulfate and histidine and yeast nitrogen base and histidine than medium only ammonium sulfate and only yeast nitrogen base.
537

Resource constrained shortest paths and extensions

Garcia, Renan 09 January 2009 (has links)
In this thesis, we use integer programming techniques to solve the resource constrained shortest path problem (RCSPP) which seeks a minimum cost path between two nodes in a directed graph subject to a finite set of resource constraints. Although NP-hard, the RCSPP is extremely useful in practice and often appears as a subproblem in many decomposition schemes for difficult optimization problems. We begin with a study of the RCSPP polytope for the single resource case and obtain several new valid inequality classes. Separation routines are provided, along with a polynomial time algorithm for constructing an auxiliary conflict graph which can be used to separate well known valid inequalities for the node packing polytope. We establish some facet defining conditions when the underlying graph is acyclic and develop a polynomial time sequential lifting algorithm which can be used to strengthen one of the inequality classes. Next, we outline a branch-and-cut algorithm for the RCSPP. We present preprocessing techniques and branching schemes which lead to strengthened linear programming relaxations and balanced search trees, and the majority of the new inequality classes are generalized to consider multiple resources. We describe a primal heuristic scheme that uses fractional solutions, along with the current incumbent, to search for new feasible solutions throughout the branch-and-bound tree. A computational study is conducted to evaluate several implementation choices, and the results demonstrate that our algorithm outperforms the default branch-and-cut algorithm of a leading integer programming software package. Finally, we consider the dial-a-flight problem (DAFP), a new vehicle routing problem that arises in the context of on-demand air transportation and is concerned with the scheduling of a set of travel requests for a single day of operations. The DAFP can be formulated as an integer multicommodity network flow model consisting of several RCSPPs linked together by set partitioning constraints which guarantee that all travel requests are satisfied. Therefore, we extend our branch-and-cut algorithm for the RCSPP to solve the DAFP. Computational experiments with practical instances provided by the DayJet Corporation verify that the extended algorithm also outperforms the default branch-and-cut algorithm of a leading integer programming software package.
538

Trade union militancy: Case studies in transport

Cribb, Margaret Unknown Date (has links)
No description available.
539

Trade union militancy: Case studies in transport

Cribb, Margaret Unknown Date (has links)
No description available.
540

Tourenplanung mittelständischer Speditionsunternehmen : Modelle und Methoden /

Rieck, Julia. January 2008 (has links)
Zugl.: Clausthal, Techn. Universiẗat, Diss., 2008.

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