<p>Plentiful research has addressed low-complexity software-based shared-memory systems since the idea was first introduced more than two decades ago. However, software-coherent systems have not been very successful in the commercial marketplace. We believe there are two main reasons for this: lack of performance and/or lack of binary compatibility.</p><p>This thesis studies multiple aspects of how to design future binary-compatible high-performance scalable shared-memory servers while keeping the hardware complexity at a minimum. It starts with a software-based distributed shared-memory system relying on no specific hardware support and gradually moves towards architectures with simple hardware support.</p><p>The evaluation is made in a modern chip-multiprocessor environment with both high-performance compute workloads and commercial applications. It shows that implementing the coherence-violation detection in hardware while solving the interchip coherence in software allows for high-performing binary-compatible systems with very low hardware complexity. Our second-generation hardware-software hybrid performs on par with, and often better than, traditional hardware-only designs.</p><p>Based on our results, we conclude that it is not only possible to design simple systems while maintaining performance and the binary-compatibility envelope, it is often possible to get better performance than in traditional and more complex designs.</p><p>We also explore two new techniques for evaluating a new shared-memory design throughout this work: adjustable simulation fidelity and statistical multiprocessor cache modeling.</p>

The aim with this thesis was to study cardiovascular disease and hypertension, use of drugs and health from an epidemiological perspective. Various methods - self-rated health (SRH), health related quality of life (HRQL) - the 36-item short form questionnaire (SF-36) - and health utility measurements - the rating scale (RS) and the time-trade off (TTO) methods - were employed. Data from the Swedish Adoption/Twin Study of Aging (SATSA) in 1984, 1987, 1990, and 1993 as well as a general population survey conducted in Uppsala County in 1995 were used. Persons who have cardiovascular disease, both with and without drug treatment, were found to have a lower SRH as compared to others in the population. Longitudinal analyses showed that SRH was relatively stable over time among persons with cardiovascular disease. Both having a low SRH and having cardiovascular disease were associated with a higher mortality rate. Hypertensives were found to have a lower HRQL than do others in the general population as measured by the SF-36. The lowest scoring was found in the general health perception scale (GH), whereas role emotional (RE) and mental health (MH) were the scales least affected by hypertension. Nearly 20 percent of the antihypertensive drug users reported side effects.The pattern of side effects was similar to that reported in clinical trials. Both hypertension itself and the drug treatment were found to have an impact on the patient's health-state utility as measured by the RS. Comparative analyses showed that health utilities and psychometric quality-of-life instruments were only moderately correlated among hypertensives. The results also showed that inequalities in HRQL were present with respect to several sociodemographic factors. In summary, this thesis revealed that persons with cardiovascular disease and/or with hypertension experience poorer health than others in the population. The poor health may be caused both by the disease and/or the drug treatment. The results in this thesis also suggested that special attention and care should be directed to persons with cardiovascular disease and/or hypertension reporting ill health. This especially is important given that low HRQL can be a riskfactor for subsequent cardiovascular events or complications which in turn might result in higher mortality rate.

Ett företags kapitalstruktur har varit ett hett diskussionsämne de senaste 50 åren. Det forskars kontinuerligt än idag gällande företagets skuldsättningsgrad och det existerar ett stort omfång av erkända förklarande teorier. En intressant fråga är varför forskarna inte har hittat en teori som förklarar alla delar av företagets val av kapitalstruktur. Uppsatsen har två viktiga syften för att möjligtvis illustrera ett nytt perspektiv av kapitalstruktursvalet. Syftet utgår ifrån att undersöka om kapitalstrukturen är rätt definierad för att kunna förklaras eftersom det är skuldsättningsgraden som utgör den originella definitionen. Den andra delen av vårt syfte utgör frågeställningen om företagets styrning kan påverka valet av kapitalstruktur. För att uppsatsen skall uppnå sitt syfte har vi valt att genomföra en kvantitativ undersökning som baseras på företagens årsredovisningar. En tvärsnittsstudie har upprättats med utgångs året 2005 varav intervallet 2005 – 2001 har använts när ett antal faktorer beräknats. Undersökningens urvalsram är baserad på bolag som var noterade på Stockholmsbörsen och OMX listorna Mid, Small och Lage Cap. Totalt har 267 bolag undersökts. Utifrån vår analys har vi dragit ett antal intressanta slutsatser som möjligtvis kan komplettera dagens forskning. Vår egen Persson-Svensson definition av kapitalstrukturen har signifikant bekräftat de flesta av de samband den traditionella definitionen teoretiskt stöder. Samtidigt visade Persson-Svensson definitionen ett antal för oss nya signifikanta samband. Undersökningen har även bekräftat ett möjligt samband mellan företagsstyrningen och företagets val av kapitalstruktur.

Acknowledging the necessity of a detailed understanding of the dynamics and contributions of wetlands in decision making processes, this research aims to identify the trade-offs between human interventions and human well-being in wetlands. Being one of the thirteen Ramsar Sites of Turkey and providing various ecosystem functions, Kizilirmak Delta was determined as the case study area of the research. Following the literature review on wetlands and their valuation, an assessment framework was developed for analyzing the trade-offs in the Kizilirmak Delta. Following this framework, first the importance, values and functions of the delta were defined by evaluation of its ecological, socio-cultural and economic structures and function analysis. Then, the pressures on the delta and their impacts were analyzed through DPSIR (Driving forces, Pressures, State, Impacts and Responses) Framework by action analysis. Finally, the trade-offs in the delta were calculated in monetary terms through valuation of the functions of the delta. Because of time and data constraints only a small portion of the functions of the delta was quantified in monetary terms. Calculated functions of the delta provide 753.531.772 TL worth of services that constitutes the 34 % of total GDP of the delta. This value was accepted as the cost of trade-offs in the delta, because the pressures on the delta would result in the loss of this value.

This thesis contains three self-contained chapters, covering different subjects but using similar methods: The Effect of Foreclosure Laws on Securitization: Evidence from U.S. States shows that mortgage loans are less likely to be securitized in states with costlier foreclosure procedures. I interpret this in light of prior literature showing a higher foreclosure risk for securitized loans, due to unwillingness to renegotiate by the agents working on behalf of investors. Moreover, the magnitude of the effect increases for loans with higher risk of default, and disappears for loans where state foreclosure laws usually do not apply. Do daughters make family firms more sustainable? studies listed companies with a family owning a large block of shares, and asks how the family composition affects the company’s policies. Creating a novel Swedish data set, I find that environmental performance improves when the family has more daughters. The effect does not seem to operate through more adult daughters leading to more female CEOs or board members, or through the appointment of family members as CEOs. Bank taxes, leverage and risk uses staggered changes in US state-level bank taxation, and documents an increase in leverage when taxes are raised. Banks partly dampen the effect by adjusting their Tier 2 capital (a lower-quality form of regulatory capital that is less able to absorb losses), and by reducing the risk on the asset side of the balance sheet as measured by regulators. / <p>Diss. Stockholm :  Stockholm School of Economics, 2015. Introduction together with 3 papers</p>

This thesis investigates the determinants of UK corporate cash holdings between 1980 and 2012. The global and long term phenomenon of corporate cash pilling has drawn significant attention from researchers. Similarly, this study aims at shedding light on the empirical relationship between cash holding and specific firm characteristics. Our preliminary research incorporates a comprehensive literature review. Towards this end, the relevant financial theory is presented and the previous empirical studies are highlighted. Afterwards, the expected results of our research are synthesized into a set of distinct hypotheses and tested with regression analysis. The empirical findings suggest that cash holdings are positively related to investment opportunity, as R&D and market to book ratio. Cash ratio is also positively related to industry cash flow volatility and negatively affected by cash flow, net working capital, capital expenditures, leverage, tax expenses, age and size. Regarding the development of the determinants of cash holdings, the study indicates that three major variables influenced cash holdings over the years of analysis. In particular, leverage, tax regime and capital expenditures significantly affect the corporate liquidity in UK market. Furthermore, the results suggest that cash holdings are mostly defined by trade off theory. Indeed, our findings offer stimulating insights on the factors that determine the firms’ cash holdings during the past three decades. These findings may be beneficial for financial managers, investors and consultants. / Στην παρούσα διατριβή εξετάζονται οι προσδιοριστικοί παράγοντες του δείκτη μετρητών σε επιχειρήσεις του Ηνωμένου Βασιλείου μεταξύ των ετών 1980 και 2012. Η διακράτηση μετρητών αποτελεί παγκόσμιο φαινόμενο και λαμβάνει της ανάλογης προσοχής από πληθώρα ερευνητών. Σε αυτή τη βάση, η μελέτη αυτή έχει ως στόχο να ρίξει φως σχετικά με την εμπειρική σχέση μεταξύ του δείκτη μετρητών και τα συγκεκριμένα χαρακτηριστικά που επηρεάζουν την ρευστότητα στις επιχειρήσεις διαχρονικά. Αρχικά η έρευνα ενσωματώνει μια βιβλιογραφική ανασκόπηση. Προς το σκοπό αυτό, οι σχετικές οικονομικές θεωρίες και οι προηγούμενες εμπειρικές μελέτες παρουσιάζονται. Στη συνέχεια, τα αναμενόμενα αποτελέσματα της έρευνας συντίθενται σε ένα σύνολο διακριτών υποθέσεων και δοκιμάζονται με ανάλυση παλινδρόμησης. Τα εμπειρικά ευρήματα υποδηλώνουν ότι ο δείκτης μετρητών σχετίζεται θετικά με τις επενδυτικές ευκαιρίες, τις δαπάνες Ε&Α και τον λόγο της αγοραίας προς τη λογιστική αξία των βιβλίων της επιχείρησης. Ο δείκτης μετρητών επίσης, σχετίζεται θετικά με την μεταβλητότητα των ταμειακών ροών του κλάδου και επηρεάζεται αρνητικά από τις ταμειακές ροές, το καθαρό κεφάλαιο κίνησης, τις κεφαλαιακές δαπάνες, την μόχλευση, τα φορολογικά έξοδα, την ηλικία και το μέγεθος των επιχειρήσεων. Όσον αφορά την εξέλιξη των προσδιοριστικών παραγόντων των ταμειακών ρευστών διαθεσίμων, η μελέτη δείχνει ότι τρεις είναι οι κύριες μεταβλητές που επηρεάζουν τη διακράτηση μετρητών κατά τη διάρκεια των χρόνων της ανάλυσης. Ειδικότερα, η μόχλευση, το φορολογικό καθεστώς και τις κεφαλαιακές δαπάνες επηρεάΖουν σημαντικά την απόφαση για εταιρική ρευστότητα στην αγορά του Ηνωμένου Βασιλείου. Επιπλέον, τα αποτελέσματα δείχνουν ότι η διακράτηση μετρητών ακολουθεί κυρίως την trade off θεωρία. Πράγματι, τα ευρήματά προσφέρουν χρήσιμες γνώσεις σχετικά με τους παράγοντες που καθορίζουν τη διακράτηση μετρητών των επιχειρήσεων κατά τη διάρκεια των τριών τελευταίων δεκαετιών. Τα ευρήματα αυτά μπορεί να είναι επωφελή για οικονομολόγους, επενδυτές και συμβούλους.

Plentiful research has addressed low-complexity software-based shared-memory systems since the idea was first introduced more than two decades ago. However, software-coherent systems have not been very successful in the commercial marketplace. We believe there are two main reasons for this: lack of performance and/or lack of binary compatibility. This thesis studies multiple aspects of how to design future binary-compatible high-performance scalable shared-memory servers while keeping the hardware complexity at a minimum. It starts with a software-based distributed shared-memory system relying on no specific hardware support and gradually moves towards architectures with simple hardware support. The evaluation is made in a modern chip-multiprocessor environment with both high-performance compute workloads and commercial applications. It shows that implementing the coherence-violation detection in hardware while solving the interchip coherence in software allows for high-performing binary-compatible systems with very low hardware complexity. Our second-generation hardware-software hybrid performs on par with, and often better than, traditional hardware-only designs. Based on our results, we conclude that it is not only possible to design simple systems while maintaining performance and the binary-compatibility envelope, it is often possible to get better performance than in traditional and more complex designs. We also explore two new techniques for evaluating a new shared-memory design throughout this work: adjustable simulation fidelity and statistical multiprocessor cache modeling.

Most of the modern wireless communication systems as WiMAX, DVB-NGH, WiFi, HSPA+ and 4G have adopted the use of multiple antennas at the transmitter and the receiver, called multiple-input multiple-output (MIMO). Space time coding for MIMO systems is a promising technology to increase the data rate and enhance the reliability of wireless communications. Space-time block codes (STBCs) are commonly designed according to the rank-determinant criteria suitable at high signal to noise ratios (SNRs). In contrast, wireless communication standards employ MIMO technology with capacity-approaching forward-error correcting (FEC) codes like turbo codes and low-density parity-check (LDPC) codes, ensuring low error rates even at low SNRs. In this thesis, we investigate the design of STBCs for MIMO systems with capacity-approaching FEC codes. We start by proposing a non-asymptotic STBC design criterion based on the bitwise mutual information (BMI) maximization between transmitted and soft estimated bits at a specific target SNR. According to the BMI criterion, we optimize several conventional STBCs. Their design parameters are shown to be SNR-dependent leading to the proposal of adaptive STBCs. Proposed adaptive STBCs offer identical or better performance than standard WiMAX profiles for all coding rates, without increasing the detection complexity. Among them, the proposed adaptive trace-orthonormal STBC can pass continuously from spatial multiplexing, suitable at low SNRs and therefore at low coding rates, to the Golden code, optimal at high SNRs. Uncorrelated, correlated channels and transmit antenna selection are considered. We design adaptive STBCs for these cases offering identical or better performance than conventional non-adaptive STBCs. In addition, conventional STBCs are designed in a way achieving the asymptotic DMT frontier. Recently, the finite-SNR DMT has been proposed to characterize the DMT at finite SNRs. Our last contribution consists of the derivation of the exact finite-SNR DMT for MIMO channels with dual antennas at the transmitter and/or the receiver. Both uncorrelated and correlated Rayleigh fading channels are considered. It is shown that at realistic SNRs, achievable diversity gains are significantly lower than asymptotic values. This finite-SNR could provide new insights on the design of STBCs at operational SNRs.

I investigated Lake Sturgeon (Acipenser fulvescens) foraging and anti-predator behaviour. My goals were to understand: (1) The role of environmental change on foraging and anti-predator behaviour trade-offs. (2) The relative cost/benefit trade-off between escape behaviour and cover-seeking behaviour. (3) How development of several independent morphological traits affects anti-predator behaviours. I used simulated river mesocosms to study Lake Sturgeon behavioural ecology under controlled conditions. I found: (1) Foraging intensity was significantly higher during the night than the day as well as in turbid environments versus clear environments, indicating that decreased turbidity alone, may in part drive anti-predator behaviour and constrain foraging activity. (2) In high-risk clear-water environments, Lake Sturgeon responded to danger by evoking an escape response and seeking cover in rocky microhabitats. However, in low-risk turbid environments, Lake Sturgeon responded to danger by seeking cover in rocky microhabitats, but not fleeing to a significant degree. Cover-seeking behaviour may therefore be a relatively low-cost/high-benefit anti-predator strategy. (3) Strong evidence for trait co-dependence between escape responses and body size, where larger fish were able to elicit stronger escape responses. I also found that cover-seeking behaviour exhibited a complex multi-tiered relationship, representing a mixture of trait compensation and trait co-specialization that is dependent on specific combinations of morphological traits. These findings are important because they help us understand: (1) The degree to which anti-predator behaviour can be influenced by changing environmental conditions. (2) The relative cost/benefit trade-off between two common anti-predator behaviours. (3) How behaviour and morphology interact in species with a complex anti-predator phenotype.

The purpose of this dissertation is to contribute to the closure of these aforementioned research gaps. Answering these calls, the following research objectives are proposed: 1. Understanding the main factors that have an influence on the capital structure decision of firms. 2. Understanding how the capital structure of firms differs among various industries and to fathom cross-sectional differences in the importance of debt determinants among industries. 3. Investigating the influence of time on the capital structure decision of firms. In specific, it must be found out whether certain debt determinants alter their effect on the capital structure decision of firms over time. 4. Studying the market-timing effect of debt financing. It must be researched how managers time the debt market when engaging in bond or loan issues. 5. Empirically proving how stylized factors and market-timing behaviour influences the transaction of equity, bond and loan issues as well as of share repurchases. 6. Finally, discussing how far the stylized facts can be explained by existing capital structure theory in order to crown the theory, whose notion can best account the observed financing patterns across the world.