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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.
281

The impact of teacher-related variables on students' Junior Secondary Certificate (JSC) mathematics results in Namibia

Akpo, Simon Eno 08 1900 (has links)
This study explored the link between teachers’ inputs and process and students’ academic achievement in Junior Secondary Certificate (JSC) Mathematics for the period 2006 to 2010.The outcome (teacher effectiveness) was obtained by means of value added measures (students’ aggregate JSC Mathematics scores for 2006 to 2010 by school). One hundred and fifty JSC schools out of a total of 573 constituted the units of analysis for the study. The data regarding teachers were obtained by means of self-administered questionnaires, and JSC Mathematics results from 2006 to 2010 were obtained from the Directorate of National Examinations and Assessment (DNEA). Multi-correlation and regression techniques at alpha =0.001; 0.05 and 0.10 were used to analyse the link between teachers’ inputs and processes, and students’ academic achievement in JSC Mathematics. The null hypotheses formulated for the study were tested at the 0.05 (5%) level of significance. In summary, it appears that the various aspects of teachers’ inputs (teachers’ educational qualifications, teaching experience, subject specialisation etc.), processes (standards-based professional development, standards-based classroom activities, and classroom management beliefs) are related to students’ academic achievement in JSC Mathematics. In particular, a linear combination of the following variables had a significant and positive association with students’ academic achievement in JSC Mathematics: teachers’ major in Mathematics (teachers’ inputs); teachers’ usage of whole class discussion (standards-based classroom activities); perceived knowledge of algebra; teachers’ professional development in interdisciplinary instruction; teachers’ review of students’ homework/assignments; and students talking to other students about how to solve mathematics problems. Teachers’ pedagogical content knowledge (PCK) in general, and some classroom practices were not significantly related to students’ academic achievements. This study, therefore, recommends that teachers’ professional development should focus on the subject matter that the teachers will be teaching, as well as alignment of teachers’ learning opportunities with real work experience using actual curriculum materials and assessment. / Educational Studies / D. Ed. (Didactics)
282

An investigation of performance in the Biology 5090 at selected high schools in Lesotho / Investigation of performance in the Biology five thousand and ninety at selected high schools in Lesotho

Lebata, Mamalanga Calextina 06 1900 (has links)
Performance in Lesotho at senior level (COSC) has been poor. One of the subjects which is performed poorly is Biology 5090. This prompted the researcher to examine factors responsible for the poor performance in Biology 5090. The study also aimed at finding ways in which teachers envisage to improve Biology 5090 performance. Data was collected from three schools through semi-structured interviews and document analysis. The study also adopted the General System Theory (GST) as the theoretical framework. Data was analyzed in line with qualitative content analysis, and from the perspective of the GST. The data analysis scheme was developed and presented (appendix P). The results of the study showed that Biology 5090 performance was affected by factors such as human resources, and the transformation process. The study also suggested ways in which Biology 5090 performance could be improved in Lesotho. These include: in-serving training, team work and others. / Science and Technology Education / M. Ed. (Natural Science Education)
283

Aspekte van die dematerialisasie van genoteerde aandele in die Suid-Afrikaanse reg

Vermaas, Maria Rosina 06 1900 (has links)
Summaries in Afrikaans and English / Text in Afrikaans / In South Africa the transfer and settlement processes associated with share transactions are essentially paper-based. The physical handling of the share certificate plays an important role in this regard. Foreign trends to reduce the movement of paper involve in broad terms the alternatives of dematerialisation and immobilisation of the share certificate. These developments cannot slavishly be followed without examining the legal nature of the South African share and share certificate. The process of immobilisation in a collective securities depository system involves no change in the nature of the shares. However, the use of a nominee where shares are held in safe custody forms a barrier between the shareholder and the issuer company which could dilute the shareholders' rights. This is even more applicable where shares are immobilised in a central depository. Further, although central depositories are based upon book-entries, they are still limited by the retention of the physical certificates. The development of electronic systems which dematerialise the share certificate must take into account the reasonable expectations of the public and should not be forced upon investors. The shareholder of a 'uncertificated' share must be placed, as far as possible, in the same position as if he had received a certificate. This requires legislation to amend present enactments and to define the rights of the shareholder. It is submitted that dematerialisation should gradually be phased in, starting with a voluntary dematerialisation in the case of holdings in the central securities depository. / In Suid-Afrika is die oordrag- en verrekeningsprosesse wat gepaardgaan met aandeletransaksies hoofsaaklik papiergebaseer. Die fisiese bantering van die aandelesertifikaat speel in die opsig 'n belangrike rol. Buitelandse pogings om die beweging van papier te verminder, neig in die algemene rigting van die dematerialisasie en immobilisasie van die aandelesertifikaat. Hierdie ontwikkelings kan nie slaafs nagevolg word sonder om die regsaard van die Suid-Afrikaanse aandeel en aandelesertifikaat te ondersoek nie. Die proses van immobilisasie in 'n kollektiewe bewaarnemerstelsel vir effekte wysig nie die aard van aandele nie. Nietemin plaas die gebruik van genomineerdes waar aandele in veilige bewaring gehou word 'n wig tussen die aandeelhouer en die uitreikermaatskappy wat die aandeelhouersregte kan verwater. Dit is selfs meer toepaslik waar aandele in 'n sentrale depot ge'lmmobiliseer word. Verder is dit so dat alhoewel sentrale depots op boekinskrywings gebaseer word, hul steeds beperk word deur die behoud van die fisiese sertifikate. Die ontwikkeling van elektroniese stelsels wat die aandelesertifikaat dematerialiseer moet rekening hou met die redelike verwagtinge van die publiek en behoort nie op beleggers afgedwing te word nie. Die aandeelhouer van 'n 'ongesertifiseerde' aandeel moet, so ver moontlik, in dieselfde posisie geplaas word asof hy 'n sertifikaat ontvang bet. Wetgewing is noodsaaklik om bestaande bepalings te wysig en die regte van die aandeelhouer te omskryf. Daar word aan die hand gedoen dat dematerialisasie stelselmatig infaseer word - aanvanklik met 'n vrywillige dematerialisasie in die geval waar aandeelhouding in sentrale bewaameming is. / Private Law / LL.D.
284

Ar informacijos apie asmens sveikatos būklę atskleidimas tretiesiems asmenims pažeidžia asmens teisę į privatų gyvenimą? / Does the Disclosure of Personal Health Information to Third Parties Violate the Individual's Right to Privacy?

Tamašauskaitė, Eglė 19 June 2014 (has links)
Informacijos apie asmens sveikatos būklę konfidencialumas yra svarbi įstatymų saugoma vertybė. Tačiau teisės doktrinoje, teisės aktuose ir teismų praktikoje pri¬pažįstama, kad teisė į privataus gyvenimo neliečiamumą nėra absoliuti. Kai ribojama asmens teisė į privatų gyvenimą, toks ribojimas turi būti numatytas įstatymų lygmenyje ir ad hoc analizuojama, ar toks ribojimas yra būtinas demokratinėje visuomenėje, siekiant ap¬saugoti teisėtą tikslą. Darbe yra nagrinėjami ir vertinami informacijos apie asmens sveikatos būklę atskleidimo tretiesiems asmenims atvejai, identifikuojami pažeidimai ir pateikiamos rekomendacijos, kokių teisinių priemonių įgyvendinimas padėtų tinkamai užtikrinti asmens teisę į šią privataus gyvenimo sritį. Darbe pristatoma asmens sveikatos informacijos konfidencialumo samprata, aprašoma, koks yra asmens, kaip paciento, teisės į privataus gyvenimo neliečiamumą reglamentavimas Lietuvoje, pristatoma šalių praktika, identifikuojami sveikatos informacijos konfidencialumo principo ribojimai, pateikiami atvejai, kuomet informacija apie asmens sveikatos būklę yra atskleidžiama pažeidžiant teisės aktus, taip pat vertinami atvejai, kai galimai ultra vires įstatymų leidėjas priima įstatymus, kurie prieštarauja LR Konstitucijai ir tarptautinėms sutartims. Darbe yra išsikeliamos dvi hipotezės: H1 – Lietuvoje be paciento sutikimo atskleidžiant informaciją apie paciento sveikatos būklę draudimo įstaigoms pažeidžiama asmens teisė į privatų gyvenimą; H2 – Lietuvoje... [toliau žr. visą tekstą] / Confidentiality of personal health information is an important value which is protected by The Convention for the Protection of Human Rights and Fundamental Freedoms, Constitution of the Republic of Lithuania and other laws. However, the right to confidentiality is not recognized as absolute in the doctrine of law, legislation and legal cases. When there is the restriction of confidentiality of personal health information, it is necessary to emphasize the principle of necessity to protect a legitimate target which is necessary in a democratic society. It is important to notice that every restriction must be provided at the level of a piece of legislation. In the paper there is analyzed and evaluated the cases of the disclosure of personal health information to third parties, identified violations and made recommendations what legislative measures should be implemented to ensure the patient's right to private life. In the paper there has set the following objectives: to analyze the current situation in Lithuania what there is the regulation of the patient's right to privacy; to present the practice of different countries about patient's right to privacy; to carry out a theoretical analysis by comparing the various scientific researches on the personal health privacy; to determine what is the restrictions for the principle of medical confidentiality; to identify privacy problems while disclosing personal health information; to reveal when information is disclosed in accordance... [to full text]
285

Les technologies nouvelles ont-elles un rôle à jouer sur un marché très concurrentiel de la Russie postsoviétique, le marché du chauffage ? (Période étudiée 1991-2008) / Do new technologies have a part to play in the very competitive heating market of the post-soviet Russia? (Period studied 1991-2008)

Lochoshvili, Maksym 16 October 2009 (has links)
Sur un exemple concret d’entreprise française disposant des technologies innovantes dans les domaines du chauffage et de la distribution d’eau et ayant un projet d’expansion vers un nouveau marché, en l’occurrence, le marché russe, l’auteur montre l’importance de ces technologies pour accéder au marché fortement différent du marché domestique. Au sein du secteur du chauffage dans un pays où, à cause des conditions climatiques froides, le besoin de se chauffer présente un besoin vital, où le retard technologique dû au phénomène historique du monopole du chauffage central collectif est particulièrement ressenti et où le marché est en pleine formation avec la montée de la concurrence, les technologies nouvelles ont sans doute un rôle capital à jouer. Comment l’entreprise porteuse de ces technologies doit-t-elle aborder le marché russe certes très prometteur, mais fragile surtout en cette période délicate de la crise économique mondiale? Quels en sont les risques et les perspectives ? Comment réussir ce marché ? Comment mettre en valeur et transférer de nouvelles solutions technologiques ? Quels sont les avantages de ce transfert pour l’entreprise, mais également pour son partenaire local, pour la région visée et pour l’Etat receveur ? Telles sont les questions que l’auteur se pose. Le rôle des technologies nouvelles va certainement au-delà d’un secteur ou d’un domaine d’activité : les technologies nouvelles apportées par des entreprises occidentales ont sans doute accéléré, en ce qui concerne la Russie, le passage d’un système économique du type soviétique vers un système de libre-échange que l’on connait sous le terme d’économie de marché. / On a specific example of a French company having innovative technologies in the field of heating and water distribution, and realizing an expansion project to a new market, in this case, the Russian market, the author shows the importance of technologies when penetrating a market strongly different from the domestic one. Within the heating sector in the country where, because of a cold climate, the need to feel warm is a vital need, where the technological backwardness due to the historical phenomenon of the central residential heating monopoly is obvious, and where market is taking shape and competition is now growing, new technologies have without doubt a capital part to play. How should a company with such technologies approach the Russian market certainly very promising, but also fragile especially in this delicate period of the world economic crisis? What are the risks and the perspectives for the company? How to succeed in this market? How to enhance the value and to transfer new technological solutions? What advantages does this transfer bring to the company, but also to the company’s local partner, to the targeted region, and to the receiving country? These are questions the author asks himself. The role of new technologies is certainly beyond a sector or a field of activity: the new technologies brought by western companies undoubtedly accelerated, as Russia is concerned, the change from the Soviet-type economic system to a free-market system, known as the market economy.
286

Droits de propriété intellectuelle et protection des plantes: approches, limites et perspectives

Honvou, Dansou Rock Sèmako 09 1900 (has links)
Le droit de la propriété intellectuelle présente, depuis quelques années, un intérêt particulier à l'évolution de la recherche sur les plantes. Ceci s'est traduit, au plan international, par l'adoption de plusieurs instruments visant à assurer une meilleure protection des investissements consentis dans ce domaine. Il s'agit notamment de la Convention de l'UPOV, qui s'inscrit dans une logique de protection par la voie sui generis avec la possibilité de délivrance de certificat d'obtention végétale aux sélectionneurs; de l'Accord ADPIC, qui, en plus de recommander un système sui generis efficace, ouvre l'option de protection par brevet ou en définitive par le cumul des deux systèmes; de la Convention sur la Diversité Biologique (CDB) et du Traité de la FAO portant sur les ressources phytogénétiques pour l'alimentation et l'agriculture, qui, favorables aux deux précédentes formes de protection, demandent que soient prises en compte des considérations relatives aux droits souverains des pays sur leurs ressources végétales, au partage des bénéfices, etc. Au plan régional, on distingue, entre autres, l'initiative de l'Afrique, visant à assurer la protection des plantes suivant une logique partagée entre l'alignement sur les normes internationales existantes (Accord de Bangui) ou l'institution d'une autre législation originale qui reflète les réalités et préoccupations du continent (Loi modèle). Il apparaît donc qu'il existe plusieurs instruments pour cerner la même réalité. Ceci est forcément la source de quelques difficultés qui sont d'ordre conceptuel, socioéconomique, environnemental et juridique. Pour les pallier, il est important que certaines conditions soient satisfaites afin d'harmoniser les points de vue entre les différents acteurs concernés par la question et d'assurer une appropriation conséquente des instruments adoptés. / The intellectual property rights have showed increasing attention to the evolution of plant research in recent years. This has been reflected, at the international level through the adoption of several measures to ensure a fairly comprehensive protection of rights arising. These measures include the Convention of the Union for the protection of Plant breeder' Rights, which is part of a logic of protection through sui generis with the possibility of issue plant breeders' rights to breeders; the Agreement on Intellectual Property Rights Related to Trade, which, in addition to recommending an effective sui generis system gives the option of protection by patent or by the combination of the two systems of law to protect plant varieties; the Convention on Biological Diversity (CBD) and the Treaty on Plant Genetic Resources for Food and Agriculture, which supported both previous forms of protection, ask to be taken into account considerations on sovereign rights of nations over their plant resources, benefit sharing, and so on. At the regional level, there are the initiative of the Africa which aimed to ensure the protection of plants following a certain vision shared between alignment on existing international standards or the institution of another original legislation which reflects the realities and concerns of the continent. It then appears that there are several tools to handle the same reality, which can be a source of difficulty. These are difficulties are conceptual, socio-economic, environmental and legal. T0 overcome these difficulties, it is important that certain conditions are met to harmonise points of view between different actors involved in the issue and ensure a consistent ownership of the instruments adopted.
287

Is Safe Haven Legislation an Efficacious Policy Response to Infant Abandonment: A Biopsychosocial Profile of the Target Population

Gruss, Stephanie Mayes 01 January 2006 (has links)
This study represents an attempt to describe the extent and features of safe haven legislation in the United States, discuss implementation issues, and to examine if the legislation is reaching its intended target audience in order to answer the question, "Is safe haven legislation an efficacious response to infant abandonment?" Safe havens are designated locations where infants can be anonymously abandoned without fear of prosecution or incarceration. As of May of 2006, forty-seven states have passed such legislation, citing the need for an alternative to unsafe infant abandonment leading to an infant's death, and an alternative to infanticide (the killing of an infant within one year of its birth). Since the initial passage of this legislation in Texas in 1999, there have been more unsafe infant abandonments than accounts of safe haven abandonments. As this legislation provides for anonymous infant abandonment researchers cannot study the population of women actually utilizing safe havens. Therefore, the study of women seeking connection with safe havens in comparison to the population of women who have engaged in infant abandonment resulting in an infant's death is considered one of the sole viable sources of insight into this problem. The scope of the research is exploratory in nature and analyses are considered preliminary due to the lack of data that exists in this area and the relative newness of the legislation.A quantitative analysis of women likely to utilize safe havens reveals that they have a mean age of 19, are unmarried, have entered into prenatal care late, have disclosed their pregnancy to someone, and are currently dating the birthfather. The findings from this analysis were compared to those from a national linked birth and infant death dataset to ascertain if women seeking safe havens have similar biopsychosocial characteristics as those engaging in unsafe abandonment leading to an infant's death. Similar biopsychosocial characteristics were found including mother's age, marital status, late entry into prenatal care, disclosure of pregnancy, and dating status. A regression analysis was used to construct a biopsychosocial profile of women likely to abandon an infant. Findings suggest that legislators and those involved with safe havens have some knowledge of their target population, but are not effectively reaching this audience, nor promoting the existence of safe havens. They also appear to be utilizing research findings on infanticide inappropriately, in order to profile their target audience. This effectively limits the promulgation of education and early identification services that could prevent both safe haven and unsafe infant abandonments. This study concludes with policy reform recommendations.
288

Essays on actively and passively managed financial products

Meinhardt, Christian 15 September 2015 (has links)
Diese Dissertation besteht aus fünf empirischen Studien. Zwei Studien befassen sich mit passiv gemanagten Finanzprodukten. Sie untersuchen den Replikationsprozess von Exchange Traded Funds (ETFs) und vergleichen hierbei die Replikationsgüte von synthetischen und physischen ETFs. Oftmals wird darauf verwiesen, dass synthetische ETFs eine höhere Replikationsgüte besitzen als physische ETFs. Dies lässt sich für Renten-ETFs bestätigen, allerdings nicht für Aktien-ETFs. Zudem wird gezeigt, dass ETFs und Indexzertifikate, die sich im direkten Wettbewerb befinden, im Hinblick auf ihre Geldmittelflüsse komplementär, allerdings nicht perfekt komplementär zueinander sind. Dieser Effekt lässt sich mithilfe der Replikationsgüte und einer Zuordnung beider Indexprodukte in verschiedene Marktnischen erklären. Weitere drei Studien befassen sich mit aktiv gemanagten Finanzprodukten. Sie widmen sich der Frage, ob mithilfe von Fondsbewertungen wie dem Feri Trust Rating, der Finanztest-Bewertung und der FondsNote die zukünftige Performance deutscher Aktienfonds prognostiziert werden kann. Hintergrund ist, dass Investoren Fondsbewertungen in ihre Anlageentscheidung einbeziehen. Sie investieren vor allem in Fonds, die eine Top-Bewertung aufweisen. Die Prognosefähigkeit von Fondsbewertungen kann sich allerdings stark voneinander unterscheiden. Die Ergebnisse zeigen, dass mithilfe der FondsNote am besten zwischen sich zukünftig besser und schlechter entwickelnden Fonds differenziert werden kann. Die Prognosefähigkeit lässt sich durch Kombination der drei Fondsbewertungen sogar erhöhen. Dies hängt allerdings von der Kombination und dem verwendeten Performancemaß/-zeitraum ab. Zudem werden Faktoren untersucht, die einen Einfluss auf die Prognosefähigkeit haben können. Es wird gezeigt, dass qualitative Bewertungsfaktoren nicht zu einer Erhöhung der Prognosefähigkeit beitragen. Stattdessen weisen die Fondskosten und das Verhalten der Investoren einen signifikanten Einfluss auf. / This thesis consists of five empirical studies that deal with actively and passively managed financial products. The first two studies focus on the replication process of exchange-traded funds (ETFs) and compare the tracking ability of ETFs based on physical replication of their benchmark indices with those of synthetic ETFs. Contrary to conventional wisdom, synthetic equity ETFs are not different in terms of tracking errors from their physical counterparts. However, synthetic fixed-income ETFs have lower tracking errors than physical fixed-income ones. Moreover, the second study examines the coexistence of ETFs and index certificates within one market by analyzing the relationship between their money flows. Evidence shows that ETFs and index certificates complement each other, but not in a perfect way. This effect can be explained by similar tracking abilities and a segmentation of investors into different market niches. The other three studies address the question if fund ratings like the Feri Trust rating, the Finanztest-Bewertung, and the FondsNote can predict the future performance of German equity mutual funds. The reason is that investors include fund ratings in their decision-making. They primarily invest in funds which have the best fund rating. However, fund rating predictability can significantly differ among fund ratings. Results indicate that the FondsNote can best distinguish between well and poorly performing funds. Predictability can be enhanced by a combination of fund ratings. However, it depends on the particular fund rating combination, the chosen performance measure, and the post-rating period. Moreover, these three studies analyze factors that could influence the predictability of fund ratings. It is shown that qualitative factors can hardly improve the predictability. By contrast, the costs of funds and the behavior of investors with regard to fund ratings significantly influence the ability to predict future performance.
289

Certificado de recebíveis do agronegócio

Winter, Marcelo Franchi 15 August 2014 (has links)
Made available in DSpace on 2016-04-26T20:23:01Z (GMT). No. of bitstreams: 1 Marcelo Franchi Winter.pdf: 927409 bytes, checksum: c232a0e890cf58ef7c2fb77318ab045c (MD5) Previous issue date: 2014-08-15 / The Agribusiness Receivables Certificate, created by the Law n. 11.076 of December, 30, 2004, in order to increase the share of the private capital in the financing of national agribusiness, is a title of credit that represents the promise to pay in cash, linked to credit rights originated in the agribusiness, issued exclusively by of an agribusiness securitization company. In practical terms, it is a specific securitization instrument applied to the agribusiness sector that grants to the investor safety, liquidity, tax benefits, high capital return and low risks, and to the borrower liquidity, better funding costs and new funding resources. This work, therefore, has the purpose to provide an detailed analysis of the agribusiness receivables certificate in Brazil in order to demonstrate that this kind of transaction can be utilized as an accelerator to the development of the agribusiness sector, as well as happened in others sectors of the economy as the case of the real state with the real state receivables certificate / O Certificado de Recebíveis do Agronegócio, criado em 2004 pela Lei 11.076, de 30 de dezembro, com a finalidade de fomentar a participação privada no financiamento do agronegócio nacional, é um título de crédito representativo da promessa de pagamento em dinheiro vinculado a direitos creditórios do agronegócio de emissão exclusiva de companhia securitizadora do agronegócio. Na prática, trata-se de um instrumento de securitização específico para o setor do agronegócio que confere ao investidor segurança, benefícios fiscais, alto retorno do capital investido e redução de riscos, e ao tomador liquidez, melhores taxas de captação e novas fontes de financiamento. O presente trabalho, portanto, tem como objetivo fazer uma análise detalhada do Certificado de Recebíveis do Agronegócio no Brasil, de forma a demonstrar que esse tipo de operação de securitização pode ser um catalizador para o desenvolvimento do setor do agronegócio, assim como já ocorreu com outros setores da economia, como foi o caso do setor imobiliário com o Certificado de Recebíveis Imobiliário
290

Identifiabilité des signaux parcimonieux structurés et solutions algorithmiques associées : application à la reconstruction tomographique à faible nombre de vues / Identifability of s-sparse structured signals and associated algorithms : application at limited view angle tomography

Nicodeme, Marc 23 November 2016 (has links)
Cette thèse étudie différents problèmes de minimisations avec des fonctions de régularisations qui promeuvent la parcimonie. Plus précisément, on souhaite reconstruire une image, que l'on suppose parcimonieuse et qui a subit une transformation après un opérateur linéaire, à l'aide de problèmes de minimisations. Dans ce manuscrit, on s'intéressera plus particulièrement à la minimisation l1 synthèse, analyse et bloc qui sont très utilisées pour reconstruction une image que l'on sait parcimonieuse. Ces minimisations produisent en pratique des résultats convaincants qui n'ont été compris théoriquement que récemment. Les différents travaux sur le sujet mettent en évidence le rôle d'un vecteur particulier appelé certificat dual. L'existence d'un certificat dual permet à la fois d'assurer la reconstruction exacte d'une image dans le cas où il n'y a pas de perturbations et d'estimer l'erreur de la reconstruction en présence de perturbations. Dans nos travaux, nous allons introduire l'existence d'un certifical dual optimal pour la minimisation l1 synthèse qui minimisent l'erreur de reconstruction. Ces résultats ayant une forte interprétation géométrique, nous avons développé un critère identifiabilité, c'est à dire que ce critère assure que l'image recherchée est l'unique solution du problème de minimisation. Ce critère permet d'étendre nos travaux à la minimisation l1 analyse, l1 bloc et à d'autres cas. / This thesis studies different minimization problems with sparses based regularization. More precisely, we want to reconstruct a sparses image, which undergone a linear transformation, with minimization problems. In this manuscript, we will be focused on l1 synthesis, analysis and block minimization which are widely used in sparse approximations. These problems offer competitive results which are theorietical understood only recntly. Different studies on the subject emphasized the contribution of a particular vector called dual certificate. The existence of this dual certificate allows simultaneously to guarantee the exact recovey of an image in noiseless case and to estimate the noise robustness in noisy case. In this work, we introduce eth existence of an optimal dual certificate for the l1 synthesis minimization which minimizes the reconstruction error. As those results have a strong geometrical interpretation, we develop an identifiability criterion which ensures the uniqueness of a solution. This criterion generalizes the work on l1 synthesis minimization tothe analysis case, block case and others.

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