Abstract Master’s thesis about „Assessing of the financial situation of a company using time series” focuses on a detailed assessment of the economic situation of the state-owned enterprise DIAMO between years 2005–2014. The theoretical part describes methods and indicators of strategic, financial and statistical analyses, which are in the next chapter sequentially applied on the analysed company. The content of the final chapter introduce proposals of elimination of the risk areas of the state-owned enterprise, while the greatest emphasis will be applied on the issue of rising shares of receivables and liabilities to total assets and ensuring positive economic result in corporate profit. The main object of this master’s thesis is assessing financial efficiency of state-owned enterprise DIAMO, afterward identifying risk areas and introducing possible precautions, which will lead to overall greater economic health of the enterprise itself.

<p>The cross-sectional variation of stock returns used to be described by the Capital Asset Pricing Model until the early 90‟s. Anomalies, such as, book-to-market effect and small firm effect undermined CAPM‟s ability to explain stock returns and Fama & French (1992) have shown that simple firm attributes, like, firm size and book-to-market value can explain the returns far better than Beta. Following Fama & French many other researchers examine the explanatory powers of CAPM and other asset pricing models. However, most of those studies use US data. There are some researches done in different countries than US, however more out-of-sample studies need to be conducted.</p><p>To our knowledge there are very few studies using the Swedish data and this thesis contributes to that small pool of studies. Moreover, the studies testing the CAPM use the unconditional version of the model. There are some papers suggesting the use of a conditional CAPM that would exhibit better explanatory powers than the unconditional CAPM. Different ways of conditioning the CAPM have been proposed, but one that we think is the least complex and possible to make use of in the business world is the dual-beta model. This conditional CAPM assumes a different relationship between beta and stock returns during the up markets and down markets. Furthermore, the model has not thoroughly been tested outside the US. Our study is the first to use the dual-beta model in Sweden. In addition, the momentum effect has lately been given some attention and Fama & French‟s (1993) three factor model has not been able to explain the abnormal returns related to that anomaly. We test the Fama & French three factor model, CAPM and Carhart‟s four factor model‟s explanatory abilities of the momentum effect using Swedish stock returns. Ultimately, our aim is to find the best model that describes stock return cross-section on the Stockholm Stock Exchange.</p><p>We use returns of all the non-financial firms listed on Stockholm Stock Exchange between September, 1997 and April, 2010. The number of companies included in our time sample is 366. The results of our tests indicate that the small firm effect, book-to-market effect and the momentum effect are not present on the Stockholm Stock Exchange. Consequently, the CAPM emerges as the one model that explains stock return cross-section better than the other models suggesting that Beta is still a proper measure of risk. Furthermore, the conditional version of CAPM describes the stock return variation far better than the unconditional CAPM. This implies using different Betas to estimate risk during up market conditions and down market conditions.</p>

The cross-sectional variation of stock returns used to be described by the Capital Asset Pricing Model until the early 90‟s. Anomalies, such as, book-to-market effect and small firm effect undermined CAPM‟s ability to explain stock returns and Fama &amp; French (1992) have shown that simple firm attributes, like, firm size and book-to-market value can explain the returns far better than Beta. Following Fama &amp; French many other researchers examine the explanatory powers of CAPM and other asset pricing models. However, most of those studies use US data. There are some researches done in different countries than US, however more out-of-sample studies need to be conducted. To our knowledge there are very few studies using the Swedish data and this thesis contributes to that small pool of studies. Moreover, the studies testing the CAPM use the unconditional version of the model. There are some papers suggesting the use of a conditional CAPM that would exhibit better explanatory powers than the unconditional CAPM. Different ways of conditioning the CAPM have been proposed, but one that we think is the least complex and possible to make use of in the business world is the dual-beta model. This conditional CAPM assumes a different relationship between beta and stock returns during the up markets and down markets. Furthermore, the model has not thoroughly been tested outside the US. Our study is the first to use the dual-beta model in Sweden. In addition, the momentum effect has lately been given some attention and Fama &amp; French‟s (1993) three factor model has not been able to explain the abnormal returns related to that anomaly. We test the Fama &amp; French three factor model, CAPM and Carhart‟s four factor model‟s explanatory abilities of the momentum effect using Swedish stock returns. Ultimately, our aim is to find the best model that describes stock return cross-section on the Stockholm Stock Exchange. We use returns of all the non-financial firms listed on Stockholm Stock Exchange between September, 1997 and April, 2010. The number of companies included in our time sample is 366. The results of our tests indicate that the small firm effect, book-to-market effect and the momentum effect are not present on the Stockholm Stock Exchange. Consequently, the CAPM emerges as the one model that explains stock return cross-section better than the other models suggesting that Beta is still a proper measure of risk. Furthermore, the conditional version of CAPM describes the stock return variation far better than the unconditional CAPM. This implies using different Betas to estimate risk during up market conditions and down market conditions.

資本資產定價模型已被廣泛使用於分析股票風險與要求報酬率之間的關係。然而，個別股票風險Beta是否足以解釋其報酬，也受到愈來愈多的質疑。Fama和French在1993年提出額外兩個因子來解釋股票報酬。我們將應用資本資產定價模型和三因子模型來分析1963年7月至2002年12月之美國的三大股票交易所上市公司。藉由一次改變分析過程中的一部分，以觀察參數估計值是否穩定。結果發現Beta_HML總是顯著且最為穩定，而Beta_SMB並不顯著。Beta經常顯著，但變動情況較大。另外，我們將考慮個別股票本身的變異，亦即將隨機效果納入考量。 / The Capital Asset Pricing Model (CAPM) has been widely used to analyze the relationship between risk and required rate of return on a stock, while it is doubted that individual stock's risk Beta has enough explanatory power for it's returns. Fama and French (1993) proposed two more factors to help explaining stock returns. We use the CAPM and the three-factor model to analyze listed companys in American stock exchanges, during the period from July 1963 to December 2002. We change part of the analyzing process a time to see if the estimates of the parameters are stable. The risk-premium Beta_HML is always significant and it performs most stable, while another risk-premium Beta_SMB is never significant. Beta is usually significant but it varies. Furthermore, we take within-stock variation into account, so random effects are considered.

Passive Intermodulation is a type of distortion affecting the sensitive receiving signals in a cellular network, which is a growing problem in the telecommunication field. One way to mitigate this problem is through Passive Intermodulation Cancellation, where the predicted noise in a signal is modeled with polynomials. Recent experiments using neural networks instead of polynomials to model this noise have shown promising results. However, one drawback with neural networks is their lack of explainability. In this work, we identify a suitable method that provides explanations for this use case. We apply this technique to explain the neural networks used for Passive Intermodulation Cancellation and discuss the result with domain expertise. We show that the input space as well as the architecture could be altered, and propose an alternative architecture for the neural network used for Passive Intermodulation Cancellation. This alternative architecture leads to a significant reduction in trainable parameters, a finding which is valuable in a cellular network where resources are heavily constrained. When performing an explainability analysis of the alternative model, the explanations are also more in line with domain expertise. / Passiv Intermodulation är en typ av störning som påverkar de känsliga mottagarsignalerna i ett mobilnät. Detta är ett växande problem inom telekommunikation. Ett tillvägagångssätt för att motverka detta problem är genom passiv intermodulations-annullering, där störningarna modelleras med hjälp av polynomiska funktioner. Nyligen har experiment där neurala nätverk används istället för polynomiska funktioner för att modellera dessa störningar påvisat intressanta resultat. Användandet av neurala nätverk är dock förenat med vissa nackdelar, varav en är svårigheten att tyda och tolka utfall av neurala nätverk. I detta projekt identifieras en passande metod för att erbjuda förklaringar av neurala nätverk tränade för passiv intermodulations-annullering. Vi applicerar denna metod på nämnda neurala nätverk och utvärderar resultatet tillsammans med domänexpertis. Vi visar att formatet på indatan till neurala nätverket kan manipuleras, samt föreslår en alternativ arkitektur för neurala nätverk tränade för passiv intermodulations-annullering. Denna alternativa arkitektur innebär en avsevärd reduktion av antalet träningsbara parametrar, vilket är ett värdefullt resultat i samband med mobilnät där det finns kraftiga begränsningar på hårdvaruresurser. När vi applicerar metoder för att förklara utfall av denna alternativa arkitektur finner vi även att förklaringarna bättre motsvarar förväntningarna från domänexpertis.

Real-time prediction of taxi demand in a discrete geographical space is useful as it can minimise service disequilibrium by informing idle drivers of the imbalance, incentivising them to reduce it. This, in turn, can lead to improved efficiency, more stimulating work conditions, and a better customer experience. This study aims to investigate the possibility of utilising an artificial neural network model to make such a prediction for Stockholm. The model was trained on historical demand data and - uniquely - crowd flow data from a cellular provider (aggregated and anonymised). Results showed that the final model could generate very helpful predictions (only off by less than 1 booking on average). External factors - including crowd flow data - had a minor positive impact on performance, but limitations regarding the setup of the zones lead to the study being unable to make a definitive conclusion about whether crowd flow data is effective in improving taxi demand predictors or not. / Prognos av taxiefterfrågan i ett diskret geografiskt utrymme är användbart då det kan minimera obalans mellan utbud och efterfrågan genom att informera lediga taxiförare om obalansen och därmed utjämna den. Detta kan i sin tur leda till förbättrad effektivitet, mer stimulerande arbetsförhållanden och en bättre kundupplevelse. Denna studie ämnar att undersöka möjligheten att använda artificiella neurala nätverk för att göra en sådan prognos för Stockholm. Modellen tränades på historisk data om efterfrågan och - unikt för studien - folkströmsdata (aggregerad och anonymiserad) från en mobiloperatör. Resultaten visade att den slutgiltiga modellen kunde generera användbara prognoser (med ett genomsnittligt prognosfel med mindre än 1 bil per tidsenhet). Externa faktorer – inklusive folkströmsdata – hade en märkbar positiv inverkan på prestandan, men begränsningar rörande framställningen av zonerna ledde till att studien inte kunde dra en definitiv slutsats om huruvida folkströmsdata är effektiva för att förbättra prognoser för taxiefterfrågan eller ej.