La première partie de mes résultats concerne les phénomènes de diffusion induits par des effets de contrainte. Nous avons étudié ces effets d’un point de vu théorique, afin de comprendre le rôle de la contrainte dans la diffusion. Les résultats montrent que l’effet de contrainte ne semble pas induire d’effet mesurable sur le coefficient cinétique à l’interface, cependant le taux de mélange semble diminuer. La seconde partie concerne des mesures expérimentales, par EXAFS et GIXRF utilisées sur des empilements Ta/a-Si/Ni/a-Si/Ta/substrat permettant de suivre la formation des phases ainsi que la croissance, à une température donnée, et ce jusqu’à la formation de la phase Ni2Si et au delà. La troisième partie concerne le système Cu-Si. Nous avons suivi les premiers stades de la formation de la phase Cu3Si, en utilisant les techniques XRD, APT, SNMS, ainsi qu’un profilomètre et une mesure de résistance quatre points sur différents échantillons réalisés par pulvérisation. Dans le cas de l’empilement Cu/a-Si/substrat, la formation de phases a suivi une cinétique linéaire. Nous avons notamment mis en évidence la formation très rapide d’une phase qui apparait directement après le premier recuit très court, démontrant ainsi le rôle déterminant de la préparation des échantillons dans l’étude des processus de formation de phases. La quatrième partie s’intéresse au silicène : cette structure bidimensionnelle de silicium dite en « nid d’abeilles », réalisée sur un substrat d’argent et qui présente de grandes similitudes avec le graphène. En utilisant de façon complémentaire les techniques AES-LEED-STM, nous avons déterminé la limite de solubilité du silicium dans l’argent. / Diffusion and related solid state reaction phenomena have been studied in four different material couples. The first section of the results concerned the diffusion related stress effects. We analyzed the question theoretically, for planar model geometry, to find the role of stress in diffusion. We obtained that stress effects do not have any measurable effects on the kinetic coefficient of the interface shift. However, the intermixing rate decreases. The second section we performed EXAFS and GIXRF experiments on sandwich structured Ta/a- Si/Ni/a-Si/Ta/substrate samples and followed the phase formation and growth at a given temperature at which the Ni2Si phase has formed and continued to grow. The third section we obtained in the Cu-Si system. We followed the early stages of phase formation of the Cu3Si phase under different circumstances. We performed XRD, APT, SNMS, profilometer and 4 wire resistance measurements on sputtering deposited samples. We found that in case of the Cu/a-Si/substrate samples the phase formation was followed by a linear kinetics. Secondly, prior to the linear phase growth, we observed an extremely fast phase formation that appeared immediately after the very first and shortest annealing, which showed that the preparation sequence of the sample is a crucial point in phase formation processes. The fourth section deals with the silicene. It is the honeycomb structured formation of Si atoms with properties similar to graphene. We investigated the dissolution of Si into Ag. We performed a combination of AES, LEED, STM measurements. We determined the dissolution limit of Si in Ag from data obtained from the AES measurements.

The thesis investigates APT attacks, which are professional targeted attacks that are characterised by long-term duration and use of advanced techniques. The thesis summarises current knowledge about APT attacks and suggests seven symptoms that can be used to check, whether an organization is under an APT attack. Thesis suggests a system for detection of APT attacks based on interaction of those symptoms. This system is elaborated further for detection of attacks in computer networks, where it uses user behaviour modelling for anomaly detection. The detector uses k-nearest neighbors (k-NN) method. The APT attack recognition ability in network environment is verified by implementing and testing this detector.

Med bakgrund till det ökade intresset för aktier och dagens ekonomiska läge är det högst aktuellt att undersöka relationen mellan makroekonomiska svängningar och aktiepriserna på den svenska börsen. Det finns flera teorier som försöker förklara hur aktiepriser förändras, en allmän slutsats är att externa faktorer påverkar priset genom oförväntade händelser. Chen, Roll och Ross konstruerade en tidsseriemodell för att studera hur oförväntade makroekonomiska faktorer påverkar aktieavkastningen på New York-börsen. Deras slutsatser landade i att oförväntade förändringar i samtliga variabler har en signifikant relation till aktieprisavkastningen. Med detta i åtanke är syftet med uppsatsen att undersöka om avkastningen på olika branscher på den svenska börsen påverkas av oförväntade månatliga förändringar i inflation (KPI), konjunkturläget (BNP), avkastningskurvan, riskpremien samt växelkursen under tidsperioden 2000-2023. Det genomförs även en jämförande analys mellan de europeiska länderna Sverige, Tyskland, Danmark och Finland. De branschindex som studeras är finans, industri, teknologi, sjukvård och detaljhandel för respektive land. Genom en multipel regressionsmodell har få signifikanta samband påvisats, däremot finner vi ett mönster i negativa respektive positiva relationer mellan oförväntade makroekonomiska händelser och aktieavkastningen för samtliga länder. Sammanfattningsvis finner vi inga tydliga skillnader i vilka branscher som påverkas av respektive riskfaktor, däremot finns en skillnad i antal signifikanta värden mellan länderna. Nationella makroekonomiska händelser påvisar flest signifikanta samband till tyska branschindex, följt av danska och finska. Minst signifikanta samband påvisas för de svenska branschindexen. En förklaring bakom resultatet kan vara att ländernas aktiemarknader är mer eller mindre effektiva och investerare på respektive marknad är olika mottagliga till ny information. Avslutningsvis ser vi det vara rimligt att både branscher och länder påverkas av riskfaktorerna i olika stor utsträckning. Att bygga en aktieportfölj med tillgångar från både olika branscher och länder är därmed betydelsefullt för att sprida sina risker. / Considering the increased interest in the stock market and the current economic situation, it is highly relevant to examine the relationship between macroeconomic fluctuations and share prices on the Swedish stock exchange. There are several theories that try to explain how stock prices change, a general conclusion is that external factors affect the price through unexpected events. Chen, Roll, and Ross constructed a time series model in order to study how unexpected macroeconomic factors affect stock returns on the New York Stock Exchange. Their conclusions resulted in that unexpected changes in all variables have a significant relationship to share price returns. With this in mind, the purpose of the essay is to investigate whether the return on various sector indexes on the Swedish stock exchange is affected by unexpected monthly changes in inflation (CPI), economic state (GNP), the term structure, the risk premium and the exchange rate during the time period 2000-2023. A comparative analysis is also carried out between the European countries Sweden, Germany, Denmark and Finland. The examined sector indexes are finance, industry, technology, healthcare and retail for each country. Through a multiple regression model, the result shows that few macroeconomic variables are significant in explaining stock returns. However, we find a pattern in negative as well as positive relationships between unexpected risk factors and stock returns for all countries. We find no significant differences in which sectors are affected by each risk factor but there is a difference in the number of significant values ​​between the countries. National macroeconomic events show the most significant relations to German sector indexes, followed by Danish and Finnish. Least significant relationships are found for the Swedish sector indexes. An explanation behind the result could be that the countries stock markets are more or less efficient and investors in each market are differently receptive to new information. Our conclusion is that we see it as reasonable that both sectors and countries are affected by the risk factors to varying degrees. Building a stock portfolio with assets from both different sectors and countries is therefore important for spreading your risks.

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This thesis examines the performance of different models of conditional betas and higher comoments in the context of the cross-section of expected stock returns, both in-sample and out-of-sample. I first examine the performance of different conditional market beta models by using monthly returns of the Fama-French 25 portfolios formed by the quintiles of size and book-to-market ratio in Chapter 3. This is a cross-sectional test of the conditional CAPM. The models examined include simple OLS regressions, the macroeconomic variables model, the state-space model, the multivariate GARCH model and the realized beta model. The results show that the state-space model performs best in-sample with significant betas and insignificant intercepts. For the out-of-sample performance, however, none of the models examined can explain returns of the 25 portfolios. Next, I examine the recently proposed realized beta model, which is based on the realized volatility literature, by using individual stocks listed in the US market in Chapter 4. I extend the realized market beta model to betas of multi-factor asset pricing models. Models tested are the CAPM, the Fama-French three-factor model and a four-factor model including the three Fama-French factors and a momentum factor. Realized betas of different models are used in the cross-section regressions along with firm-level variables such as size, book-to-market ratio and past returns. The in-sample results show that market beta is significant and additional betas of multi-factor models can reduce although not eliminate the effects of firm-level variables. The out-of-sample results show that no betas are significant. The results are robust across different markets such as NYSE, AMEX and NASDAQ. In Chapter 5, I test if realized coskewness and cokurtosis can help explain the cross-section of stock returns. I add coskewness and cokurtosis to the factor pricing models tested in Chapter 4. The results show that the coefficients of coskewness and cokurtosis have the correct sign as predicted by the higher-moment CAPM theory but only cokurtosis is significant. Cokurtosis is significant not only in-sample but also out-of-sample, suggesting cokurtosis is an important risk. However, the effects of firm-level variables remain significant after higher moments are included, indicating a rejection of higher-moment asset pricing models. The results are also robust across different markets such as NYSE, AMEX and NASDAQ. The overall results of this thesis indicate a rejection of the conditional asset pricing models. Models of systematic risks, i.e. betas and higher comoments, cannot explain the cross-section of expected stock returns.

Determination of the stock expected return is an important element of asset management. This paper presents an Arbitrage Pricing Theory model, which strives to estimate the expected return explaining the historical volatility of the stock prices. This paper presents the model as it was introduced, necessary extension for application to a small market included. Statistical methods on which the model has been build are discussed -- factor analysis completed by principal component analysis. In the practical part, the model is applied to the Czech market with an assessment of the success of the application. The forces which were expected to represent risk factors for the market have been examined as well. It will be shown that the model may contribute to the understanding of risk behaviour of the stocks.

Titanium nitride (TiN) films are widely applied as diffusion barrier layers in microelectronic devices. The continued miniaturization of such devices not only poses new challenges to material systems design, but also puts high demands on characterization techniques. To gain understanding of diffusion processes that can eventually lead to failure of the barrier layer and thus of the whole device, it is essential to develop routines to chemically and structurally investigate these layers down to the atomic scale. In the present study, model TiN diffusion barriers with a Cu overlayer acting as the diffusion source were grown by reactive magnetron sputtering on MgO(001) and thermally oxidized Si(001) substrates. Cross-sectional transmission electron microscopy (XTEM) of the pristine samples revealed epitaxial, single-crystalline growth of TiN on MgO(001), while the polycrystalline TiN grown on Si(001) exhibited a [001]-oriented columnar microstructure. Various annealing treatments were carried out to induce diffusion of Cu into the TiN layer. Subsequently, XTEM images were recorded with a high-angle annular dark field detector, which provides strong elemental contrast, to illuminate the correlation between the structure and the barrier efficiency of the single- and polycrystalline TiN layers. Particular regions of interest were investigated more closely by energy dispersive X-ray (EDX) mapping. These investigations are completed by atom probe tomography (APT) studies, which provide a three-dimensional insight into the elemental distribution at the near-interface region with atomic chemical resolution and high sensitivity. In case of the single-crystalline barrier, a uniform Cu-enriched diffusion layer of 12 nm could be detected at the interface after an annealing treatment at 1000 °C for 12 h. This excellent barrier performance can be attributed to the lack of fast diffusion paths such as grain boundaries. Moreover, density-functional theory calculations predict a stoichiometry-dependent atomic diffusion mechanism of Cu in bulk TiN, with Cu diffusing on the N-sublattice for the experimental N/Ti ratio. In comparison, the polycrystalline TiN layers exhibited grain boundaries reaching from the Cu-TiN interface to the substrate, thus providing direct diffusion paths for Cu. However, the microstructure of these columnar layers was still dense without open porosity or voids, so that the onset of grain boundary diffusion could only be found after annealing at 900 °C for 1 h. The present study shows how to combine two high resolution state-of-the-art methods, TEM and APT, to characterize model TiN diffusion barriers. It is shown how to correlate the microstructure with the performance of the barrier layer by two-dimensional EDX mapping and three-dimensional APT. Highly effective Cu-diffusion barrier function is thus demonstrated for single-crystal TiN(001) (up to 1000 °C) and dense polycrystalline TiN (900 °C).

El presente trabajo tiene como objetivo analizar el uso y aplicación del modelo de valoración de activos de capital, CAPM, como herramienta de planificación y evaluación financiera, comparándolo con otros modelos alternativos. El CAPM propone una relación entre el riesgo y rendimiento de un activo. El riesgo está representado por el coeficiente beta, que mide la sensibilidad del instrumento financiero en relación con el riesgo sistemático, ya sea en un portafolio de activos o en la valoración de una empresa. Debido a que existen críticas sobre la validez del CAPM, en este estudio se busca conocer la efectividad que tiene el uso y la aplicación del modelo. Para ello, se han buscado evidencias empíricas, en diferentes países, y sectores económicos en las que se compara el CAPM con otros modelos alternativos, tales como el APT o el de Tres Factores Fama y French que, según la investigación realizada, serían los más utilizados. Los resultados de esta investigación muestran que el CAPM no ofrece necesariamente resultados positivos significativos en los estudios revisados. Sin embargo, ello no quiere decir que el CAPM no sea un modelo suficiente para predecir la relación riesgo – rentabilidad en los casos en los que se aplica. Se concluye por ello que, a pesar de que existen modelos alternativos tratando de superar las limitaciones del CAPM, hoy en día este modelo sigue siendo el más utilizado fundamentalmente por su sencillez y por su capacidad de explicar y predecir, de manera suficiente, en la mayoría de las aplicaciones generales. / The objective of this paper is to analyze the use and application of the capital asset pricing model, CAPM, as a planning and financial evaluation tool and to compare it with other alternative models. The CAPM propose a relationship between the risk and return of an asset. The risk is represented by coefficient called beta, which measures the sensitivity of the financial asset in relation to it´s systematic risk, either in a portfolio or in the valuation of a company. Given that there are controversies about the validity of the CAPM, the study is gad is to understand the effectiveness of the use and application of the model. In order to do that, evidence, in different countries and economic sectors, is presented in which the CAPM is compared with other alternative models, such as the APT or the Fama and French Three Factor, according to this investigation would be the most used. The results of this investigation shown that, the CAPM, even though it is not able to offer significant positives results in the studies reviewed. However, it is not a sufficient model for predictins the risk - return relationship in the cases where it applies. It is concluded for that, although there are alternatives models trying to overcome the limitations of the CAPM, this model is nowadays the most used yet, fundamentally because of its simplicity and its ability to explain and predict, in a sufficient fashion, in most of the general applications. / Trabajo de Suficiencia Profesional

As the stock market plays an important role in the global economy and Chinese economy become progressively significant part of the world economy, we are interested in the Chinese stock market. After we compared the methods on the stock market, we choose to use the CAPM and the APT model on Chinese stock market. As a lot papers study on the Main Board of Chinese stock market, we pay our attention on the SME Board and the ChiNext Board of Chinese stock market. We put the samples from the SME Board and the ChiNext Board into the regression models which are based on the CAPM and the APT model, and then we can use the regression models to forecast the long returns. Comparing the forecast ln returns with the true ln returns, we may find that the CAMP or the APT model can forecast better on the SME Board and the ChiNext Board. The systematic risk is the only factor we put the regression model based on the CAPM. For the regression model based on the APT model, we use three factors which are the systematic risk, daily exchange volume and the volatility. Our results show that the APT model can explain factors better than the CAPM for the samples from the SME Board and the ChiNext Board. On the other hand, we could not find evidence that the APT Model can forecast better than the CAPM for the SME Board and the ChiNext Board.

Scania’s discount rate - the return requirement of investments - refers to Scania’s WACC or weighted average cost of capital. The capital markets return requirement on equity and the credit market interest cost of borrowing is weighted to become the single discount rate, the WACC. The purpose of this study is to investigate which asset pricing model of APT and CAPM Scania should use in their WACC calculations. The company now uses a group WACC of 11 percent which is used in all company levels. The problem with this is that investments in low-risk markets will be discounted by the same factor as high-risk markets, which can result in a misleading NPV. The objective is to create a differentiated WACC which gives an opportunity to compare investments with different risk profiles. The study proposes the best fitting model, given by evaluating APT and CAPM in a Scania context. To achieve a differentiated WACC a new method is created, The JCJ-Method. The method uses an industry index as a benchmark of Scania. The results indicate that APT is the better model for Scania in the differentiating context. / Carl-Johan Peel