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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.
511

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).
512

Business restructuring of tangible goods : The restructuring of an ongoing concern with respect to profit potential in the context of the Swedish arm’s length rule.

Olsson, Andreas January 2012 (has links)
Enterprises when transacting with each other, are not subjected to the same market forces as independent enterprises. From a Swedish perspective the applicable rule to transactions between associated enterprises is chap. 14 para. 19. Both the Swedish arm’s length rule and its international equivalence are abstract rules of law as they merely provides the legal ramification if associated enterprises interact in a manner that independent enterprises would not. The international equivalence to the Swedish arm’s length rule is not a separate rule of law per se it is the gateway by which the Swedish rule is made applicable in international situations, through the use of a double tax agreement, with the fundamental principle that a double tax agreement can only limit, never expand a countries right to tax. The OECD Guidelines governing the general aspects of transfer pricing states that the fundamental meaning of the Guidelines is to find ways of establishing a price used between associated enterprises that are similar to what independent enterprise would conclude. The first step towards finding such a price is though the comparability analyses were all the relevant characteristics of the transferred goods is analysed. The chapter in the Guidelines that governs business restructurings is meant to be applied alongside the general aspects of transfer pricing. The Guidelines proposed way of finding an appropriate price for the transaction of a branch of production with respect to profit potential is with special consideration to risks. The profit potential is irrevocably linked with the risks transferred since it is a presumption that with increased risk there is a potential for higher profits. Although the risks are the most important aspect there are other things to look at such as other options realistically available and benefits from concluding a business restructuring.
513

Implementation of a Program Address Generator in a DSP processor / Implementering av en Programadress generator i en DSP processor

Waltersson, Roland January 2003 (has links)
The purpose of this thesis is to construct a"Program Address Generator"(PAG) to a 24-bit Harvard type, RISC DSP processor using the VHDL language. The PAG is a part of the program control unit, and should consist of the following units: A system stack for storing jump and loop information. A program counter, a status register, a stack pointer, an operating mode register and two registers called loop address and loop counter register, to support hardware loops. The PAG handles the fetch stage of the processor pipeline, and should handle instructions such as the jump, subroutine jump, return from subroutine/interrupt and loop instructions, among others. The PAG was successfully designed, and its function verified through extensive tests, where common combinations of ASM instructions were tested. Files for automated testing was created, to support easy testing if only small changes are applied to the PAG.
514

The citizenship education system in Canada from 1945-2005 : an overview and assessment

Richet, Evan 01 May 2007 (has links)
There has been a significant interest amongst immigrants in obtaining Canadian citizenship, dating all the way back to the end of World War Two in 1945. This thesis is particularly interested in what knowledge and skills these immigrants obtain as a result of their experiences in the citizenship education programs provided by the federal government prior to them becoming official citizens of Canada.<p>This thesis has a number of objectives. First, it intends to track the evolution of citizenship policy in Canada from 1945 to the present time, with a particular focus on the changes made to the citizenship education system. Secondly, an assessment of the adequacy of the changes made to the citizenship education system will be conducted, focusing primarily on whether or not those changes have provided newcomers to Canada with the knowledge and skills necessary to be active and informed citizens. Finally, suggestions will be offered as to how citizenship education programs can best provide new Canadians with a more well-rounded quality of citizenship. <p>The evolution of citizenship policy and the assessment of the changes made to citizenship education from 1945 to the present time reveal a number of findings, with many of them pointing to citizenship education policy and programming in Canada as being inadequate. The findings identify a lack of political leadership and financial resources provided for citizenship training initiatives, as well as a painfully basic citizenship education curriculum provided for newcomers to Canada. <p>The central contention of this thesis is that the federal government regards citizenship education as little more than a short-term goal. In other words, the priority is to speed up the processing of newcomers rather than to develop good citizens. Immigrants are provided with basic knowledge and language skills, but are largely left to fend for themselves once official citizenship has been attained. This short-term focus has resulted in a diminution of the quality and importance of Canadian citizenship and has impaired the ability of new citizens to feel comfortable participating in Canadian society. <p>The significance of these findings is that policy makers need to develop a long-term citizenship education strategy that focuses on providing long-term benefits to new citizens to Canada. Such a strategy will help to maximize the potential contributions of the growing immigrant population to Canadian society and will provide much needed clarity of roles and responsibilities to citizenship education service providers and instructors.
515

Global Optimization of Monotonic Programs: Applications in Polynomial and Stochastic Programming.

Cheon, Myun-Seok 15 April 2005 (has links)
Monotonic optimization consists of minimizing or maximizing a monotonic objective function over a set of constraints defined by monotonic functions. Many optimization problems in economics and engineering often have monotonicity while lacking other useful properties, such as convexity. This thesis is concerned with the development and application of global optimization algorithms for monotonic optimization problems. First, we propose enhancements to an existing outer-approximation algorithm | called the Polyblock Algorithm | for monotonic optimization problems. The enhancements are shown to significantly improve the computational performance of the algorithm while retaining the convergence properties. Next, we develop a generic branch-and-bound algorithm for monotonic optimization problems. A computational study is carried out for comparing the performance of the Polyblock Algorithm and variants of the proposed branch-and-bound scheme on a family of separable polynomial programming problems. Finally, we study an important class of monotonic optimization problems | probabilistically constrained linear programs. We develop a branch-and-bound algorithm that searches for a global solution to the problem. The basic algorithm is enhanced by domain reduction and cutting plane strategies to reduce the size of the partitions and hence tighten bounds. The proposed branch-reduce-cut algorithm exploits the monotonicity properties inherent in the problem, and requires the solution of only linear programming subproblems. We provide convergence proofs for the algorithm. Some illustrative numerical results involving problems with discrete distributions are presented.
516

The Budget Constrained Discrete Time/cost Trade-off Problem In Project Networks

Degirmenci, Guvenc 01 August 2008 (has links) (PDF)
The time/cost trade-off models in project management aim to compress the project completion time by accelerating the activity durations at an expense of additional resources. The budget problem in discrete time/cost trade-off scheduling selects the time/cost mode -among the discrete set of specified modes- for each activity so as to minimize the project completion time without exceeding the available budget. There may be alternative modes that solve the budget problem optimally, however each solution may have a different total cost value. In this study we aim to find the minimum cost solution among the optimal solutions of the budget problem. We analyze the structure of the problem together with its linear programming relaxation and derive some mechanisms for reducing the problem size. We solve the reduced problem by linear programming relaxation and branch and bound based approximation and optimization algorithms. We find that our branch and bound algorithm finds optimal solutions for medium-sized problem instances in reasonable times and the approximation algorithms produce high quality solutions. We also discuss the way our algorithms could be used to construct the time/cost trade-off curve.
517

One-warehouse Multi-retailer Problem Under Inventory Control And Transportation Policies

Solyali, Oguz 01 December 2008 (has links) (PDF)
We consider a one-warehouse multi-retailer system where the warehouse orders or receives from its supplier and replenishes multiple retailers with direct shipping or multi-stop routing over a finite time horizon. The warehouse has the knowledge of external (deterministic) demands at the retailers and manages their inventories while ensuring no stock-out. We consider two problems with direct shipping policy and two problems with routing policy. For the direct shipping policy, the problem is to determine the optimal replenishments for the warehouse and retailers such that the system-wide costs are minimized. In one problem, the warehouse decides about how much and when to ship to the retailers while in the other problem, inventory level of the retailer has to be raised up to a predetermined level whenever replenished. We propose strong mixed integer programming formulations for these problems. Computational experiments show that our formulations are better than their competitors and are very successful in solving the problems to optimality. For the routing policy, the problem is to decide on when and in what sequence to visit the retailers and how much to ship to a retailer so as to minimize system-wide costs. In one problem, the warehouse receives given amounts from its supplier while in the other the warehouse decides on its own replenishments. We propose branch-and-cut algorithms and heuristics based on strong formulations for both problems. Computational results reveal that our procedures perform better than their competitors in the literature for both problems.
518

Multi Resource Agent Bottleneck Generalized Assignment Problem

Karabulut, Ozlem 01 May 2010 (has links) (PDF)
In this thesis, we consider the Multi Resource Agent Bottleneck Generalized Assignment Problem. We aim to minimize the maximum load over all agents. We study the Linear Programming (LP) relaxation of the problem. We use the optimal LP relaxation solutions in our Branch and Bound algorithm while defining lower and upper bounds and branching schemes. We find that our Branch and Bound algorithm returns optimal solutions to the problems with up to 60 jobs when the number of agents is 5, and up to 30 jobs when the number of agents is 10, in less than 20 minutes. To find approximate solutions, we define a tabu search algorithm and an &amp / #945 / approximation algorithm. Our computational results have revealed that these procedures can find high quality solutions to large sized instances very quickly.
519

A Branch And Bound Algorithm For Resource Leveling Problem

Mutlu, Mustafa Cagdas 01 August 2010 (has links) (PDF)
Resource Leveling Problem (RLP) aims to minimize undesired fluctuations in resource distribution curves which cause several practical problems. Many studies conclude that commercial project management software packages can not effectively deal with RLP. In this study a branch and bound algorithm is presented for solving RLP for single and multi resource, small size networks. The algorithm adopts a depth-first strategy and stores start times of non-critical activities in the nodes of the search tree. Optimal resource distributions for 4 different types of resource leveling metrics can be obtained via the developed procedure. To prune more of the search tree and thereby reduce the computation time, several lower bound calculation methods are employed. Experiment results from 20 problems showed that the suggested algorithm can successfully locate optimal solutions for networks with up to 20 activities. The algorithm presented in this study contributes to the literature in two points. First, the new lower bound improvement method (maximum allowable daily resources method) introduced in this study reduces computation time required for achieving the optimal solution for the RLP. Second, optimal solutions of several small sized problems have been obtained by the algorithm for some traditional and recently suggested leveling metrics. Among these metrics, Resource Idle Day (RID) has been utilized in an exact method for the first time. All these solutions may form a basis for performance evaluation of heuristic and metaheuristic procedures for the RLP. Limitations of the developed branch and bound procedure are discussed and possible further improvements are suggested.
520

Automated anatomical labeling of the bronchial branch and its application to the virtual bronchoscopy system

Mori, Kensaku, Hasegawa, Jun-ichi, Suenaga, Yasuhito, Toriwaki, Jun-ichiro 02 1900 (has links)
No description available.

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