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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.
1

Amélioration des performances du polycarbonate et des mélanges polycarbonate/polystyrène par des copolymères à blocs ABC / Improvement of the performances of polycarbonate and polycarbonate/polystyrene blends by using ABC block copolymers

Dubromez, Vincent 18 December 2009 (has links)
Le polycarbonate (PC) est un polymère thermoplastique particulièrement intéressant pour de nombreuses applications industrielles et biomédicales, de par ses propriétés d’usage exceptionnelles (transparence, résistance mécanique et thermique). Néanmoins, il présente deux défauts majeurs : sa viscosité élevée et sa sensibilité à l’entaille. L’objectif de cette étude est de remédier à ces inconvénients, tout en préservant sa transparence. Pour ce faire, trois voies ont été envisagées : (i) amélioration de la fluidité par ajout de polystyrène (PS), (ii) renforcement par des copolymères à blocs de type poly(styrène-b-butadiène-b-méthacrylate de méthyle) (SBM) et (iii) utilisation simultanée de PS et de SBM. L’incorporation du PS permet de fluidifier le PC, tout en conservant sa transparence. Toutefois, les propriétés mécaniques des mélanges PC/PS sont inférieures à celles du PC seul. L’étude des mélanges binaires PC/SBM montre que la nature et la fraction de copolymère SBM incorporé, ainsi que la viscosité de la matrice, jouent un rôle déterminant sur les propriétés finales. L’étude des mélanges ternaires PC/PS/SBM démontre qu’il est possible d’obtenir une amélioration des propriétés au choc, toute en préservant la transparence du PC, à condition de générer une morphologie homogène et bien dispersée. Ceci implique une combinaison optimale entre la fluidité de la matrice PC, la nature et la fraction de copolymères à blocs et du PS dans le mélange, et un choix judicieux des paramètres technologiques de mise en œuvre. / Polycarbonate (PC) is a widely used thermoplastic polymer for numerous industrial and biomedical applications, due to its exceptional use properties (transparency, mechanical and thermal behavior). Nevertheless, the PC exhibits two major defects: high viscosity and poor notch impact properties. The goal of the present study was to propose a solution for these two issues, while preserving the PC transparency. Three ways were investigated: (i) the decrease of viscosity via adding polystyrene (PS), (ii) the improvement of notch impact behavior by adding poly(styrene-b-butadiene-bmethylmethacrylate) block copolymers (SBM) and (iii) simultaneous use of PS and SBM. Adding PS to a PC matrix does decrease its viscosity, while preserving the transparency. However, the mechanical properties of PC/PS blends are inferior to those of the neat PC. The experimental study on binary PC/SBM blends point out the great influence of the nature and proportion of the copolymer in the blend, as well as of the matrix viscosity, on the final properties of the blends. The investigation of the ternary PC/PS/SBM blends demonstrate that it is possible to obtain an improvement of the notch impact properties, while preserving the PC transparency – by generating a homogeneous and well dispersed blend morphology. This requires an optimal combination between the matrix fluidity, the nature and the proportion of block copolymers and PS, and also an appropriate choice of the processing conditions.
2

The North American Free Trade Agreement : trade protection and competition issues

Lopez, Luis F. Rojas January 1994 (has links)
No description available.
3

A new era for the EU-SADC trade relationship: a critical analysis of the EU-SADC EPA and the ipmact on regional intergration in SADC and South Africa's role in the negotiations/

Keller, Sara Regina. Unknown Date (has links) (PDF)
Thesis (L.L.M) -- University of the Western Cape, 2007. / Includes bibliographic references (leaves 87-95).
4

The cost of bypassing MFN obligations through GSP schemes: EU-India GSP case and its implications for developing countries.

Kabajulizi, Julian January 2005 (has links)
The principal objective of this research was a critical examination of the Generalised System of Preference schemes as a form of special and differential treatment under the Enabling Clause with specific reference to the complaint brought against the European Union (EU) by India regarding the EU's granting of tariff preferences to developing countries with illegal drug trafficking problem.
5

Regionalization and Marketing Mix Strategies of a company (A study of Telecommunication Company)

Awan, Anam ul Haq, Ali, Shahzad January 2006 (has links)
<p>Our study deals with the concept of regional trade blocs or open borders </p><p>(Nordic Region) and their impact on the Marketing Mix Strategies of the firm. The </p><p>purpose of our study is to analyze the regionalization concept as company point </p><p>of view and then its impact on the marketing mix strategies of a company </p><p>operating in Nordic Region. To get the appropriate data for this, we studied a </p><p>telecommunication company based in Norway and operating in Denmark and </p><p>Sweden as well. We adopted the inductive approach and case study method, </p><p>and our study is based on our research findings, on the basis of which we </p><p>developed our own model. The model discusses certain variables and factors </p><p>which influence the marketing mix decisions of the company. </p><p>The study results show that company felt the reality of open market and </p><p>trying to get the advantages of this opportunity by modifying or reorganizing its </p><p>marketing mix strategies according to the open market conditions. Innovation and </p><p>product development according to the customer demands in different markets </p><p>forced the company to take attention about their product line and product </p><p>components. Competition in local and regional market forced the company and </p><p>they based their price strategy on competition so competition became a driving </p><p>force for the company’s price strategy. Open borders gave a number of </p><p>alternatives to position the products and Telenor is using different distribution </p><p>channels which vary from market to market and country to country. Company </p><p>adopted trans-border strategy for the easiness of their end consumers and used </p><p>different brand names in different markets but with single logo at all.</p>
6

Regionalization and Marketing Mix Strategies of a company (A study of Telecommunication Company)

Awan, Anam ul Haq, Ali, Shahzad January 2006 (has links)
Our study deals with the concept of regional trade blocs or open borders (Nordic Region) and their impact on the Marketing Mix Strategies of the firm. The purpose of our study is to analyze the regionalization concept as company point of view and then its impact on the marketing mix strategies of a company operating in Nordic Region. To get the appropriate data for this, we studied a telecommunication company based in Norway and operating in Denmark and Sweden as well. We adopted the inductive approach and case study method, and our study is based on our research findings, on the basis of which we developed our own model. The model discusses certain variables and factors which influence the marketing mix decisions of the company. The study results show that company felt the reality of open market and trying to get the advantages of this opportunity by modifying or reorganizing its marketing mix strategies according to the open market conditions. Innovation and product development according to the customer demands in different markets forced the company to take attention about their product line and product components. Competition in local and regional market forced the company and they based their price strategy on competition so competition became a driving force for the company’s price strategy. Open borders gave a number of alternatives to position the products and Telenor is using different distribution channels which vary from market to market and country to country. Company adopted trans-border strategy for the easiness of their end consumers and used different brand names in different markets but with single logo at all.
7

The cost of bypassing MFN obligations through GSP schemes: EU-India GSP case and its implications for developing countries.

Kabajulizi, Julian January 2005 (has links)
The principal objective of this research was a critical examination of the Generalised System of Preference schemes as a form of special and differential treatment under the Enabling Clause with specific reference to the complaint brought against the European Union (EU) by India regarding the EU's granting of tariff preferences to developing countries with illegal drug trafficking problem.
8

Three essays in public finance

Chen, Shiyuan. January 2008 (has links)
Thesis (Ph. D.)--Georgia State University, 2008. / Title from file title page. Sally Wallace, committee chair; Yongsheng Xu, David L. Sjoquist , Dillon Alleyne, committee members. Electronic text (142 p.) : digital, PDF file. Description based on contents viewed Nov. 20, 2008. Includes bibliographical references (p. 125-141).
9

Strategic interaction among international trading blocs

Wemhöner, Frederik. January 1992 (has links)
Thesis (Ph. D.)--University of Georgia, 1992. / Includes bibliographical references (leaves 66-68).
10

Learning, selection and coding of new block transforms in and for the optimization loop of video coders / Apprentissage, sélection et codage de nouvelles transformées de blocs dans et pour la boucle d’optimisation de codeurs vidéo

Puri, Saurabh 09 November 2017 (has links)
Les transformées sont un élément clé dans les systèmes de codage vidéo par blocs. Cette thèse approfondit les schémas d’apprentissage à multiples transformées. Une première contribution de ce travail est consacrée à l’évaluation de schémas d’apprentissage de transformées de deux types en ligne et hors ligne. Les deux approches sont comparées en détail et leur pertinence respective révélées. Nous proposons ensuite plusieurs techniques afin d’améliorer la stabilité du système d’apprentissage et réduire le coût de la signalisation. Une seconde contribution concerne les schémas d’apprentissage multi-transformées hors ligne déjà connus qui sont étendus avec pour objectifs de 1) fournir des transformées plus génériques et moins biaisées, 2) obtenir des gains de compression plus élevés, 3) réduire la complexité d’encodage et de décodage. On propose un schéma dit IMDTC (Improved Mode Dependent Transform Competition) qui offre un gain de codage très significatif, plus de 5% par rapport à HEVC standard sous la configuration All Intra (AI), avec une augmentation de complexité raisonnable. Enfin, l’adaptabilité au contenu de l’apprentissage hors ligne est étendue en explorant une nouvelle approche d’apprentissage des transformées basée sur des jeux de transformées adaptées à des contenus. Plusieurs ensembles contenant de multiples transformées sont appris sur différents contenus et regroupés en jeu. Lors du codage d’une région donnée d’une image, un ensemble de transformées est sélectionné localement à partir du jeu. Les résultats numériques montrent le potentiel élevé de cette approche par rapport aux approches classiques en ligne et hors ligne. / Transforms are a key element in block-based video coding systems which, in conjugation with quantization, is important for the overall compression efficiency of the system. This thesis explores multipletransform- based learning schemes. A first contribution of this work is dedicated to the evaluation of transform learning schemes with two flavors 1) online learning, and 2) offline learning. The two approaches are compared against each other and their respective appropriability is studied in detail. Some novel techniques are proposed in this work to 1) improve the stability of the learning scheme and 2) to reduce the signaling cost. In a second contribution of this thesis, the offline multiple-transform learning schemes already known in the literature are further extended with the aims to altogether 1) provide more generic transforms that are less biased towards specific classes of contents, 2) achieve higher compression gains, 3) reduce encoding and decoding computational complexity. An improved Mode Dependent Transform Competition (IMDTC) scheme is proposed which provides a considerable gain of over 5% compared to standard HEVC under All Intra (AI) configuration at a complexity just 2.9 times the standard HEVC. Finally, the content adaptability aspect of the offline learning is explored through a novel content-adapted pool-based transform learning approach where several multiple-transform sets are learned on different contents and pooled together. During the coding of a given region of an image, one transform set is selected locally from the pool. Numerical results show the high potential of this approach against the conservative online and offline approaches.

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