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The financial crisis and the bankruptcy of Lehman Brothers in 2008 lead to harder regulations for the banking industry which included larger capital reserves for the banks. One of the parts that contributed to this increased capital reserve was the the credit valuation adjustment capital charge which can be explained as the market value of the counterparty default risk. The purpose of the credit valuation adjustment capital charge is to capitalize the risk of future changes in the market value of the counterparty default risk. One financial contract that had a key role in the financial crisis was the credit default swap. A credit default swap involves three different parts, a contract seller, a contract buyer and a reference entity. The credit default swap can be seen as an insurance against a credit event, a default for example of the reference entity. This thesis focuses on the study and calculation of the credit valuation adjustment of credit default swaps. The credit valuation adjustment on a credit default swap can be implemented with two different assumptions. In the first case, the seller (buyer) of the contract is assumed to be default risk free and then only the buyer (seller) contributes to the default risk. In the second case, both the seller and the buyer of the contract is assumed to be default risky and therefore, both parts contributes to the default risk. / Finanskrisen och Lehman Brothers konkurs 2008 ledde till hårdare regleringar för banksektorn som bland annat innefattade krav på större kapitalreserver för bankerna. En del som bidrog till denna ökning av kapitalreserverna var kreditvärdighetsjusteringens kapitalkrav som kan förklaras som marknadsvärdet av motpartsrisken. Syftet med kreditvärdighetsjusteringens kapitalkrav är att kapitalisera risken för framtida förändringar i marknadsvärdet av motpartsrisken. Ett derivat som hade en nyckelroll under finanskrisen var kreditswappen. En kreditswap innefattar tre parter, en säljare, en köpare och ett referensföretag. Kreditswappen kan ses som en försäkring mot en kredithändelse, till exempel en konkurs på referensföretaget. Detta arbete fokuserar på studier och beräkningar av kreditvärdesjusteringen på kreditswappar. Kreditvärdesjusteringen på en kreditswap kan implementeras med två olika antaganden. I det första fallet antas säljaren (köparen) vara riskfri och då bidrar bara köparen (säljaren) till konkursrisken. I det andra fallet antas både säljaren och köparen bidra till konkursrisken.

Made available in DSpace on 2014-06-12T18:08:10Z (GMT). No. of bitstreams: 2 arquivo8041_1.pdf: 1032286 bytes, checksum: cb40cd20e21c163acad02ddabf34f51f (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2002 / Neste trabalho foi projetado e montado um sistema de evaporação de filmes finos utilizando um laser de Nd:YAG como a fonte de energia de evaporação com comprimentos de onda de 1064 nm e 532 nm. Esta técnica é conhecida como: Deposição com Laser Pulsado (Pulsed Laser Deposition, PLD). O material escolhido para evaporação foi o CdS. A caracterização dos filmes foi feita através de técnicas como difração de raios-X, microscopia eletrônica, transmissão, fotoluminescência, e absorção no infravermelho médio e distante por transformada de Fourier. Verificamos a obtenção de filmes cristalinos com estrutura wurtzita e com eixo c altamente orientado na direção perpendicular à superfície do substrato. Até onde conhecemos este é um resultado original para filmes evaporados com 532 nm. Através dos espectros de absorção e transmissão foram obtidos parâmetros importantes como espessura do filme, índice de refração, gap óptico e variação relativa da concentração de impurezas. Foi constatada uma diminuição na concentração de impurezas por excesso de Cd com o aumento da fluência e a diminuição do comprimento de onda de evaporação. O aumento da fluência também acarretou uma diminuição do gap do material como reflexo das variações na concentração de impurezas. As bandas de impurezas foram estudadas pela técnica de absorção no infravermelho médio e distante por transformada de Fourier. Os espectros de fotoluminescência obtidos mostraram picos de máxima intensidade no verde. Este aspecto é um indicador da alta qualidade dos filmes evaporados

This paper complements theoretical and methodological considerations regarding social media in critical discourse studies as it addresses social media content policies as a key contextual element. Specifically, this paper argues that - and why - the exploration of content policies and their enforcement is indispensable when approaching social media platforms and social media data in particular from a critical perspective. A number of researchers have already begun to identify contextual elements that require particular attention when viewing social media and social media data through a CDS lens. However, social media sites' content policies, as pervasive contextual element, have not received adequate research attention yet. Drawing on Computer-Mediated Discourse Analysis (CMDA) and recent developments in Social Media CDS (SM-CDS), this paper first demonstrates the existing gap in research. Then, it contends that social media sites' content policies deserve more detailed attention in SM-CDS, argues why this is the case and elaborates on the different aspects of content policies and policy enforcement that require examination. After detailed theoretical discussion of this, empirical evidence to support this argument is presented in the form of a case study of Wikipedia and Wikipedia data.

Nos travaux antérieurs ont développé la débenzylation DIBAL-H de α-, β- et γ-CDBn, qui génère une fonctionnalisation regiosélective sur le bord primaire. De plus, la déméthylation DIBAL-H de α- et β-CDMe donne accès à une modification régiosélective sur le bord secondaire sans changer la conformation de l'unité suger. La déméthylation DIBAL-H optimisée pourrait également influer sur la modification du bord primaire. En raison de la grande cavité du γ-CD sur la solubilisation et l'encapsulation C60, l'un des objectifs de mon travail est d'obtenir le γ-CDMe sélectivement modifié sur le bord secondaire. Sur la base de la déméthylation DIBAL-H de α-, β- et γ-CDMe, 7 conjugués α-CD-C60 sont soumis à l'évaluation biologique en tant qu'agents antiviraux potentiels et un conjugué β-CD-C60 est en cours d'étude en tant que potentiel anti-allergique agent. En outre, le conjugué 2A-γ-CDMe-C60 avec attachement de jante secondaire présente la plus grande solubilité dans l'eau parmi les conjugués CD-C60 et les complexes γ-CD / C60. Le conjugué 2A-γ-CDMe-C60 et le conjugué 6A-γ-CDMe-C60 avec fixation du jonc primaire ont montré un rendement quantique 1O2 plus élevé que les conjugués CD-C60 rapportés sous irradiation UV. À la lumière de la méthodologie de la débenzylation DIBAL-H, 6 complexes α- et β-CDMe-Ag hydrosolubles (Cu, Au) ont été synthétisés. On a obtenu des structures cristallines à rayons X d'α-CDMe-AgCl à la fois dans CDCl3 et dans de l'eau. Par ailleurs, nous avons obtenu le monomère α-CDMe-CuCCPh qui est stable dans l'eau. De plus, α- et β-CDMe-AuCl ont été comme catalyseurs en cyclosomérisation regiosélective, énantiéselective et lactonisation dans DCM et eau. / Our previous work have developed DIBAL-H debenzylation of α-, β- and γ-CDBn, which generates regioselective functionalization on the primary rim. Moreover, DIBAL-H demethylation of α- and β-CDMe gives an access to regioselective modification on the secondary rim without changing the conformation of suger unit. Meanwhile, the optimized DIBAL-H demethylation could affordes the modification on the primary rim as well. Because of the large cavity of γ-CD on C60 solubilization and encapsulation, one of the goals of my work is to obtain the selectively modified γ-CDMe on the secondary rim. Based on DIBAL-H demethylation of α-, β- and γ-CDMe, 7 α-CD-C60 conjugates are under the biological evaluation as potential antiviral agents and a β-CD-C60 conjugate is being studied as a potential anti-allergic agent. Furthermore, 2A-γ-CDMe-C60 conjugate with secondary rim attachement displays the highest water-solubility among CD-C60 conjugates and γ-CD/C60 complexes. Both 2A-γ-CDMe-C60 conjugate and 6A-γ-CDMe-C60 conjugate with primary rim attachment showed higher 1O2 quantume yield than the reported CD-C60 conjugates under UV irradiation. In light of the methodology of DIBAL-H debenzylation, 6 water-soluble α- and β-CDMe-Ag(Cu, Au) complexes have been synthesized. X-ray crystal structures of α-CDMe-AgCl in both CDCl3 and water have been obtained. Besides, we got monomer α-CDMe-CuCCPh which is stable in water. In addition, α- and β-CDMe-AuCl have been as catalysts in regioselective, enantioselective cycloisomerization and lactonization in DCM and neat water.

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This thesis analyses the relationship between the increasingly important sovereign CDS spreads and exchange rates, from a macroeconomic perspective. It attempts to address an existing gap in the empirical literature, which to date has paid limited attention to the role of exchange rates in influencing sovereign CDS spreads, and vice versa. In exploring the relationship between sovereign CDS markets and foreign exchange markets, I find relatively strong evidence of a causal relationship between these two variables. In a longer-term cointegrating relationship, I find that sovereign CDS spreads have different impacts (positive or negative) on exchange rates depending on the structural characteristics of the domestic export sectors of the countries studied. Turning to the second moment of exchange rates and sovereign CDS spreads, I examine the relationship between the volatility of sovereign CDS spreads and the volatility of exchange rates for developed economies (proxied by an index containing 10 Eurozone countries) and emerging economies (proxied by Brazil and Russia). My findings point to different mechanisms of transmission between sovereign CDS markets and foreign exchange markets with regard to developed and emerging economies: for developed economies, exchange rates affect sovereign CDS spreads through the volatility, whilst in emerging economies the exchange rates affect sovereign CDS spreads at the price level. To further analyse the determinants of sovereign CDS spreads, I incorporate additional macroeconomic fundamentals in addition to exchange rates into a model to explain sovereign CDS spreads. The results show that sovereign CDS spreads are indeed driven by most macroeconomic fundamentals. However, these results do not hold during periods of economic turmoil, in which the rising risk aversion of investors becomes a principal influence behind the sovereign CDS spreads. As changes in exchange rates are able to capture changes to risk aversion through trading in foreign exchange markets, the exchange rate retains its explanatory power to sovereign CDS spreads in ‘normal’ as well as ‘crisis’ conditions. Overall, the study provides strong support for the claim that exchange rates are an important determinant of sovereign CDS spreads, in addition to the interest rate which is highlighted in the literature review. The exchange rate – as an important fundamental indicator – can reflect the general domestic economic status, the relative international competitiveness of countries, as well as capture changes in risk aversion among investors. Therefore, using exchange rates to explain sovereign CDS spreads can help to account for both domestic and international dimensions of the ‘health’ of an economy as well as changes in investors’ attitudes.

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No description available.

X-ray medical imaging provides invaluable medical information, while subjecting patients to hazardous ionizing radiation. The dosage that the patient is exposed to may be reduced, at the cost of image resolution. A technology that promises lower dosage for a given resolution is direct conversion digital imaging, typically based on amorphous Selenium semiconductor. Sufficient exposure should be used for the first exposure to avoid subsequent exposures; a challenge is then to reduce the necessary exposure for a suitable image. To quantify how little radiation the detector can reliably discriminate, one needs an analysis of the variance that 1/f and white noise contribute to the signal of such detectors. An important consideration is that the dark current, which varies with time, is subtracted from the photo-current, to reduce the spurious spatial variance in the image. In this thesis, the variance that 1/f noise contributes to integrating detectors is analysed, for a very general integrating detector. Experiments were performed to verify the theoretical results obtained for the 1/f noise variance contribution.