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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.
41

En räntebärande e-krona : Makroekonomiska effekter på kort till lång sikt samt rollen som ett penningpolitiskt styrmedel / An Interest-Bearing E-krona : Macroeconomic effects on the short to long run and the role as a monetary policy instrument

Andersson, Mathias, Helgesson, Olle January 2020 (has links)
Sverige rör sig mot ett kontantlöst samhälle i en takt som uppmärksammas internationellt. Det svenska betalningsväsendet kan komma att genomgå omfattande strukturella förändringar inom snar framtid. En av dessa förändringar kan antas vara införandet av den digitala centralbanksvalutan (CBDC) e-kronan. Då språnget mot det kontantlösa samhället börjat uttrycka sig i resten av världen är olika länders centralbanker mitt uppe i att reda ut de makroekonomiska effekter som en CBDC medför. Då e-kronan är ett nytt fenomen existerar det inte någon omfattande empirisk forskning, utan förhållandesättet är fortfarande teoretiskt. Vi undersöker därför de makroekonomiska effekter som kan tänkas uppstå vid införandet av en räntebärande e-krona från kort till lång sikt, samt diskuterar möjligheten för att använda e-kronan som ett penningpolitiskt styrmedel. Vi finner utifrån en modifiering av IS-MP-PC-modellen att en räntebärande e-krona som sätts i enlighet med inflationsmålet har liknande makroekonomiska effekter som styrräntan har idag. Vidare utvidgar vi en överlappande generationsmodell och visar på en undanträngning av reala tillgångar på lång sikt vid höga räntenivåer på e-kronan relativt till räntan på reala tillgångar i ett intergenerationellt sammanhang. / Sweden is moving towards a cashless society at an internationally recognized pace. The Swedish payment system may undergo extensive structural changes in the near future. One of these changes is assumed to be the introduction of the digital central bank currency (CBDC) e-krona. As the leap towards a cashless society has begun to manifest itself in the rest of the world, various countries' central banks are in the midst of figuring out the macroeconomic effects that a CBDC brings. As the e-krona is a new phenomenon, there is no extensive empirical research and the approach is still theoretical. We therefore investigate the macroeconomic effects that may arise from the introduction of an interest-bearing e-krona from the short to the long term and discuss the possibility of using the e-krona as a monetary policy instrument. By modifying the IS-MP-PC-model we find that an interest-bearing e-krona set in accordance with the inflation target has similar macroeconomic effects as the policy rate today. Furthermore, we extend an overlapping generations model and show a crowding out effect of real assets in the long run when the interest rate on the e-krona is high relative to the interest rate on real assets in an intergenerational context.
42

Optimization of memory management on distributed machine / Optimisation de la gestion mémoire sur machines distribuées

Ha, Viet Hai 05 October 2012 (has links)
Afin d'exploiter les capacités des architectures parallèles telles que les grappes, les grilles, les systèmes multi-processeurs, et plus récemment les nuages et les systèmes multi-cœurs, un langage de programmation universel et facile à utiliser reste à développer. Du point de vue du programmeur, OpenMP est très facile à utiliser en grande partie grâce à sa capacité à supporter une parallélisation incrémentale, la possibilité de définir dynamiquement le nombre de fils d'exécution, et aussi grâce à ses stratégies d'ordonnancement. Cependant, comme il a été initialement conçu pour des systèmes à mémoire partagée, OpenMP est généralement très limité pour effectuer des calculs sur des systèmes à mémoire distribuée. De nombreuses solutions ont été essayées pour faire tourner OpenMP sur des systèmes à mémoire distribuée. Les approches les plus abouties se concentrent sur l’exploitation d’une architecture réseau spéciale et donc ne peuvent fournir une solution ouverte. D'autres sont basées sur une solution logicielle déjà disponible telle que DMS, MPI ou Global Array, et par conséquent rencontrent des difficultés pour fournir une implémentation d'OpenMP complètement conforme et à haute performance. CAPE — pour Checkpointing Aided Parallel Execution — est une solution alternative permettant de développer une implémentation conforme d'OpenMP pour les systèmes à mémoire distribuée. L'idée est la suivante : en arrivant à une section parallèle, l'image du thread maître est sauvegardé et est envoyée aux esclaves ; puis, chaque esclave exécute l'un des threads ; à la fin de la section parallèle, chaque threads esclaves extraient une liste de toutes modifications ayant été effectuées localement et la renvoie au thread maître ; le thread maître intègre ces modifications et reprend son exécution. Afin de prouver la faisabilité de cette approche, la première version de CAPE a été implémentée en utilisant des points de reprise complets. Cependant, une analyse préliminaire a montré que la grande quantité de données transmises entre les threads et l’extraction de la liste des modifications depuis les points de reprise complets conduit à de faibles performances. De plus, cette version est limitée à des problèmes parallèles satisfaisant les conditions de Bernstein, autrement dit, il ne permet pas de prendre en compte les données partagées. L'objectif de cette thèse est de proposer de nouvelles approches pour améliorer les performances de CAPE et dépasser les restrictions sur les données partagées. Tout d'abord, nous avons développé DICKPT (Discontinuous Incremental ChecKPoinTing), une technique points de reprise incrémentaux qui supporte la possibilité de prendre des points de reprise discontinue lors de l'exécution d'un processus. Basé sur DICKPT, la vitesse d'exécution de la nouvelle version de CAPE a été considérablement augmenté. Par exemple, le temps de calculer une grande multiplication matrice-matrice sur un cluster des ordinateurs bureaux est devenu très similaire à la durée d'exécution d'un programme MPI optimisé. En outre, l'accélération associée à cette nouvelle version pour divers nombre de threads est assez linéaire pour différentes tailles du problème. Pour des données partagées, nous avons proposé UHLRC (Updated Home-based Lazy Relaxed Consistency), une version modifiée de la HLRC (Home-based Lazy Relaxed Consistency) modèle de mémoire, pour le rendre plus adapté aux caractéristiques de CAPE. Les prototypes et les algorithmes à mettre en œuvre la synchronisation des données et des directives et clauses de données partagées sont également précisées. Ces deux travaux garantit la possibilité pour CAPE de respecter des demandes de données partagées d'OpenMP / In order to explore further the capabilities of parallel computing architectures such as grids, clusters, multi-processors and more recently, clouds and multi-cores, an easy-to-use parallel language is an important challenging issue. From the programmer's point of view, OpenMP is very easy to use with its ability to support incremental parallelization, features for dynamically setting the number of threads and scheduling strategies. However, as initially designed for shared memory systems, OpenMP is usually limited on distributed memory systems to intra-nodes' computations. Many attempts have tried to port OpenMP on distributed systems. The most emerged approaches mainly focus on exploiting the capabilities of a special network architecture and therefore cannot provide an open solution. Others are based on an already available software solution such as DMS, MPI or Global Array and, as a consequence, they meet difficulties to become a fully-compliant and high-performance implementation of OpenMP. As yet another attempt to built an OpenMP compliant implementation for distributed memory systems, CAPE − which stands for Checkpointing Aide Parallel Execution − has been developed which with the following idea: when reaching a parallel section, the master thread is dumped and its image is sent to slaves; then, each slave executes a different thread; at the end of the parallel section, slave threads extract and return to the master thread the list of all modifications that has been locally performed; the master includes these modifications and resumes its execution. In order to prove the feasibility of this paradigm, the first version of CAPE was implemented using complete checkpoints. However, preliminary analysis showed that the large amount of data transferred between threads and the extraction of the list of modifications from complete checkpoints lead to weak performance. Furthermore, this version was restricted to parallel problems satisfying the Bernstein's conditions, i.e. it did not solve the requirements of shared data. This thesis aims at presenting the approaches we proposed to improve CAPE' performance and to overcome the restrictions on shared data. First, we developed DICKPT which stands for Discontinuous Incremental Checkpointing, an incremental checkpointing technique that supports the ability to save incremental checkpoints discontinuously during the execution of a process. Based on the DICKPT, the execution speed of the new version of CAPE was significantly increased. For example, the time to compute a large matrix-matrix product on a desktop cluster has become very similar to the execution time of the same optimized MPI program. Moreover, the speedup associated with this new version for various number of threads is quite linear for different problem sizes. In the side of shared data, we proposed UHLRC, which stands for Updated Home-based Lazy Release Consistency, a modified version of the Home-based Lazy Release Consistency (HLRC) memory model, to make it more appropriate to the characteristics of CAPE. Prototypes and algorithms to implement the synchronization and OpenMP data-sharing clauses and directives are also specified. These two works ensures the ability for CAPE to respect shared-data behavior
43

Stratégies de routage multi-chemin dans les réseaux sans fil multi-sauts

Doghri, Inès 30 May 2012 (has links) (PDF)
Un réseau sans fil multi-saut est un ensemble d'entités mobiles et/ou fixes formant un réseau dynamique temporaire avec ou sans l'aide de toute administration centralisée. Cette particularité rend le routage problématique en cas d'instabilité des éléments qui composent les communications non directes. Afin de palier ces problèmes, de nouvelles formes de routage sont utilisées comme le routage multi-chemin (MC). Le routage MC permet d'envoyer les données sur des chemins multiples et semble être une solution efficace pour ces réseaux. Le but de cette thèse est d'étudier les techniques de routage MC dans un contexte sans fil multi-saut en vue d'obtenir de meilleures performances. Nous avons choisi pour notre étude une extension MC du protocole OLSR, appelée MP-OLSR. Nous évaluons ses performances sous divers scénarios sous NS-2. Ces tests d'évaluation nous ont amenés à mettre en 'evidence deux problèmes dans MP-OLSR : la réactivité du protocole de routage MC suite à des ruptures de route et la stratégie de répartition des données sur les chemins multiples. Nous avons étudié la réactivité de tels mécanismes dans MP-OLSR. Nous avons proposé trois nouvelles techniques de réparation de pannes qui diminuent les temps de rétablissement d'une route et réduisent le taux de perte des flux transmis. Nous proposons aussi un mécanisme qui détecte la dégradation de la qualité des liens durant le transfert d'un trafic de données. Les informations déduites de ce mécanisme servent à adapter la proportion de trafic à affecter à chaque chemin selon les conditions réseaux. Cette nouvelle variante du protocole MP-OLSR est évaluée par simulation.
44

Vliv pohádkových postav na vývoj mentálně postižených dětí / The fairy-tail characters influence on a mentally affected children progression The influence of fairytale characters on the development of mentally handicapped children

KREJČOVÁ, Irena January 2009 (has links)
Fairy tales are a basic way of mediating social, ethic, and cultural values to children. The form of a story is accessible and understandable to children. By their definiteness fairytale characters enable children to understand and differentiate the good and the evil, the right and the wrong, the positive and the negative more easily. Mental handicap influences the whole personality and proves by a lower level of rational abilities and a different way of perception. Nobody has specified so far to what extent fairytale characters influence the development of mentally handicapped children. The aim of my work was to find out whether mentally handicapped children know and perceive fairytale characters and whether they are influenced by them similarly to healthy children. The examined complex included ten children with a medium-severe mental retardation aged 12 {--} 19. The research was carried out by semi {--} structured dialogues with children, their parents, and school workers. I also used a method of structured observation and anylysis of products. All the ten children meet with fairy tales regularly. All children prefer audiovisual forms of fairy tales. The parents of three children stated that they also read fairy tales to their children. The children were able to name 3 {--} 18 fairy tales. They were able to present their favourite characters together with their characteristcs. In nine cases it was a positive character, one child gave a negative character. Eight children could name both positive and negative characters. A typical fairytale character of a devil is understandable better than a character of a water sprite, which is ambiguous for them. In a free drawing fairytale topics occured only sporadically in figural and technical motives. The occurence of fairytale motives in spontaeous children´s play and their conversation was also sporadic. Understanding a fairy tale and fairytale characters is limited with mentally handicapped children. Although audiovisual forms of fairy tales are criticised in literature, for these children they seem to be more accessible. TV interpretation of a fairy tale is more understandable for them. It mediates information for more senses simultaneously and thus it has a bigger chance to capture them.
45

Preparação de Aços Rápidos Ao Molibdênio Com Adição de Carboneto de Nióbio Através de Técnicas de Metalurgia do Pó

ANTONELLO, Rodrigo Tecchio 31 January 2012 (has links)
Submitted by Eduarda Figueiredo (eduarda.ffigueiredo@ufpe.br) on 2015-03-10T14:59:09Z No. of bitstreams: 2 Antonello, R. T._DISSERTAÇÃO.pdf: 11868567 bytes, checksum: 37f02ff74a4b9a3a993814861c25e4db (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-10T14:59:09Z (GMT). No. of bitstreams: 2 Antonello, R. T._DISSERTAÇÃO.pdf: 11868567 bytes, checksum: 37f02ff74a4b9a3a993814861c25e4db (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2012 / FACEPE / Aços rápidos obtidos por técnicas de metalurgia do pó (MP) apresentam propriedades melhoradas quando comparados aos aços rápidos obtidos pelo processo convencional. A inserção do nióbio (Nb) como elemento de liga nos aços rápidos iniciou-se com o objetivo de substituir elementos de liga como o vanádio (V) e o tungstênio (W). A sinterização com fase líquida é uma das técnicas de fabricação de aços rápidos obtidos pela metalurgia do pó. O objetivo deste trabalho é a obtenção dos aços rápidos AISI M2 e M3:2 com e sem a adição de carboneto de nióbio (NbC) por compactação uniaxial a frio e sinterização a vácuo com fase líquida. Os pós dos aços rápidos AISI M2 e M3:2 foram processados por moagem de alta energia (MAE) com e sem adição de carboneto de nióbio e compactado uniaxialmente a frio a 700 MPa e sinterizados nas temperaturas de 1240 °C, 1270 °C, para os aços sem a adição de NbC e 1250 °C, para os aços com a adição de 6% de NbC. Os pós dos aços rápidos AISI M2 e M3:2 com a adição de carboneto de nióbio (NbC) processados por uma técnica de moagem de alta energia (MAE) foram caracterizados por difração de raios-X e Microscopia eletrônica de varredura (MEV) e espectroscopia de baixa energia dispersiva de raios-X (EDS) para avaliar a incorporação do reforço do carboneto de nióbio (NbC) aos pós elementares dos aços rápidos. Amostras dos aços rápidos AISI M2 e M3:2 sinterizadas a vácuo com e sem a adição de carboneto de nióbio (NbC) tiveram suas densidades avaliadas e as microestruturas foram caracterizadas por microscopia óptica (MO) para avaliar as microestruturas (porosidades, tamanho e distribuição de carbonetos). Os aços rápidos AISI M2 e M3:2 objetos desse trabalho de pesquisa foram avaliados ainda no que concerne a propriedade mecânica de dureza através de ensaios de dureza Vickers (HV).
46

The use of dioxy MP 14 (stabilized aqueous chlorine dioxide) to control environmental airborne microorganisms

Mbamalu, Oluchi Nneka January 2009 (has links)
Magister Pharmaceuticae - MPharm / Dioxy MP 14 is a locally developed form of stabilized chlorine dioxide in an aqueous medium. It has all the sanitizing properties of chlorine dioxide gas, a neutral compound of chlorine in the +IV oxidation state, which has been used extensively as a non-toxic sterilizing agent with various applications. In this study, Dioxy MP14 was tested in a commercial chicken pen to determine its effectiveness as an environmental sanitizing agent. Control of environmental microbes in a chicken pen is important to ensure healthy birds and optimum egg production. The biocide was introduced via an overhead misting system with a variable dosing pump at various daily frequencies.The effectiveness of environmental microorganism control was determined with air settle plates. The health and performance of the chickens were evaluated and compared to chickens in a control pen.The results show a decrease in airborne microbial load in the treated pen. Better egg production and lower mortality of the chickens in the treated pen compared to the control pen, indicate effective environmental microbial control was achieved with a residual 7.46 ppm Dioxy MP 14 at a daily dose given for 5 minutes every 2 hours.This study was a pilot study, with encouraging results, for an extended study to investigate the feasibility of introducing Dioxy MP 14 through a misting system in a clinical environment (clinics and hospitals) to control airborne pathogens like Mycobacterium tuberculosis thereby reducing the infection risks for clinical workers and medical staff.
47

Analyzing components of barrier coatings in different fractions during a repulping process.

Särnholm, Evelina January 2021 (has links)
During paper manufacturing, coating and adhesives are added to paper and cardboard to improve quality and durability. When the paper is later recycled or becoming new paper, the coatings may pollute the water used in the recycling process. Thus, it is important to know in which fraction these coatings finish during the process. In this study, laboratory made samples that mimic the repulping and paper making process is used. The different fractions of the processes were analyzed for a clay as well as a polymer coating. Metal content from clay coating is analyzed using inductively coupled plasma-mass spectrometry and microwave plasma-atomic emission spectrometry. For analyzing polymer coating, gas chromatography-mass spectrometry was used. From the result of the analysis the Reject sample, which was collected with a bigger mesh sieve in a repulping system, contained the highest amount of both clay and polymer coating. The other sample fractions from the repulping process and paper making process, did not contain as high mass content of either clay nor polymer coating.
48

Fluoride removal by low-cost adsorbents

Bernheim, Fredrik January 2022 (has links)
Fluoride, the most abundant form of fluorine, is an ion released into the environment, mainly via anthropogenic sources and erosion of mineral rocks. Although the element is well known for its health benefits on teeth and bones, it can as well be a harmful pollutant. In some areas on earth, the population can not obtain drinking water that is below the guideline limits of fluoride, which is set to 1.5 mg/L by the world health organization (WHO). Therefore there is a relevance to develop methods that can clean the waters from excess fluoride. The potential problems when it comes to finding these types of methods is that they can be expensive. However, materials generated as residues in industrial processes may be low in cost. In this thesis, silicon reduced AOD-slag, a material generated as a by-product from the production of stainless steel, was examined by its fluoride adsorption behavior and adsorption capacity. The concentrations of fluoride were measured with ion chromatography (IC) and the concentration of metals were analyzed with microwave plasma atomic emission spectroscopy (MP-AES). Additionally pH and conductivity were measured. The functionality of the material surface was analyzed with isotherm modeling, where the Sips isotherm model was tested. Moreover, optimization of the slag was performed by heat treating the material, as well as a sorption kinetics test on both optimized and original slags. The results from the analysis indicated that the material corresponds well to the Sips isotherm. Considering this result it is suggested that at low concentrations, the surface can be characterized as heterogeneous, with different binding energies at different available sites. At higher concentrations the Sips-model explains the surface to be saturated when a monolayer of fluoride is formed. Therefore the binding on the slag surface can be described to have an inner-sphere and covalent character. The metal analysis showed that calcium ions are released from the slag when in aqueous solutions. The presence of calcium in the liquid samples are believed to result in formations of solid calcium fluoride (CaF2), precipitated on the slag surface. Lastly, the maximum fluoride removal is believed to differ between different types of AOD-slag, where there as well are possibilities to optimize the material.
49

Minding the gap. Filling the public security gap in post-war societies.

McKay, Terrence Penn January 2010 (has links)
No electronic version of the thesis exists at present. For the print version please use the link above to the University of Bradford Library Catalogue.
50

Comparison of MP-AES and ICP-MS for thedetermination of potentially toxic elements in (polluted) plant material

Baysal, Ramazan January 2024 (has links)
The purpose of this study was to assess the metal content present in pine needles collected from an old shooting range known for elevated lead levels in the soil by different analytical methods. The focus on conifers originated from their evergreen nature year-round, and their ability to absorb potentially harmful elements. Research on needles as biomonitors for environmental contamination, particularly in areas affected by heavy metal pollution, has gained significant global attention. Four trees, two Norway spruces (Picea abies), and two Scots pines (Pinus sylvestris) were identified within the designated area. Samples of conifer needles were collected in plastic bags. The needles underwent washing, drying, and grinding into powder for subsequent digestion method and quantitative determination of metal content using ICP-MS and MPAES. The study focused on elements commonly found in various types of ammunition, specifically manganese, iron, nickel, copper, zinc, molybdenum, antimony, and lead. Results obtained from both analytical methods, which was only manganese, showed statistically significant differences. During the analysis, only manganese could be quantified using MPAES, as the other analytes were below the detection limit. For ICP-MS, the LOD values were much lower, making this method more suitable, as all analytes were above LOD and could be quantified. The recovery values for the CRM were good for all elements when ICP-MS was utilized. However, the calculated recovery value for manganese decreased based on the results obtained from MPAES compared to the calculated recovery value for manganese based on the results obtained from ICP-MS. Interestingly, the analysis of conifer needles revealed no noticeable contamination from the shooting range. Instead, it highlighted variances among different pine needle species. The metal content in the pine needles remained within acceptable limits according to external literature sources.

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