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Notions of Dependence with Applications in Insurance and FinanceWei, Wei January 2013 (has links)
Many insurance and finance activities involve multiple risks. Dependence structures between different risks play an important role in both theoretical models and practical applications. However, stochastic and actuarial models with dependence are very challenging research topics. In most literature, only special dependence structures have been considered. However, most existing special dependence structures can be integrated into more-general contexts. This thesis is motivated by the desire to develop more-general dependence structures and to consider their applications.
This thesis systematically studies different dependence notions and explores their applications in the fields of insurance and finance. It contributes to the current literature in the following three main respects. First, it introduces some dependence notions to actuarial science and initiates a new approach to studying optimal reinsurance problems. Second, it proposes new notions of dependence and provides a general context for the studies of optimal allocation problems in insurance and finance. Third, it builds the connections between copulas and the proposed dependence notions, thus enabling the constructions of the proposed dependence structures and enhancing their applicability in practice.
The results derived in the thesis not only unify and generalize the existing studies of optimization problems in insurance and finance, but also admit promising applications in other fields, such as operations research and risk management.
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Ultra Wide Band Sigma-Delta modulator in CMOS090 / UWB Sigma-Delta modulator i CMOS090Jonsson, Fredrik January 2004 (has links)
Today the frequency spectrum is full of wireless standards. The most common technique being used is the frequency modulation. To take advantage of this and the technology improvement a new wireless communication standard is being developed. This standard is using a low power impulse modulation method, allowing it to overlap with other standards. The proposed standard called IEEE802.15.3a is applied at an Ultra Wide Band and has potential to be used both in interchip and intrasystem communication, since it allows a very high data density. In this thesis the analog to digital converter is designed, which is one part of a communication system. Although the signal bandwidth is very wide the converter is designed as a Sigma-Delta modulator, which is most suitable for low-speed applications. Its main advantages over high-speed converters are less area and less power consumption. The goal of this project is to investigate if the CMOS090 process technology will be sufficient for reaching a signal-to-noise ratio, SNR, of 30 dB in a signal band of 264 MHz. The main limiting factor during the design of the modulator is the excess feedback delay. This delay degrades the SNR and can even make the system unstable. At a feedback delay of 83 ps and a sampling frequency of 6.336 GHz, the maximum SNR achieved was 27 dB. At this high frequency the modulator is close to instability. Hence, to ensure stability a maximum sampling frequency of 4.224 GHz is chosen, achieving a SNR of 19 dB. The effect of the feedback delay can be reduced either by using a different structure or by using compensation methods, either of them would probably allow a SNR above 30 dB.
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Likviditetsstrategi på Stockholmsbörsen : En studie om likviditetspremiens existens och dess eventuella överavkastningSvartholm, Per, Uhrberg, Magnus January 2012 (has links)
Bakgrund: Det har tidigare konstaterats att det existerar ett samband mellan aktiers likviditet och dess avkastning. Bevis för detta har främst gått att finna på utländska aktiemarknader. På den svenska aktiemarknaden har tidigare utförda studier konstaterat att detta samband inte existerar. Vi vill därför göra en studie på den svenska aktiemarknaden, vilken delvis innefattar en ny tidsperiod för att se om någon likviditetspremie existerar. Syfte: Vårt syfte med denna studie var att undersöka om det är möjligt att uppnå en högre avkastning genom att investera i en portfölj med relativt sett illikvida aktier jämfört med en portfölj bestående av likvida aktier på Stockholmsbörsen samt undersöka om faktorerna likviditet, betavärde samt företagsstorlek signifikant påverkar portföljernas eventuella överavkastning jämfört mot ett lämpligt index. Metod: Vi har skapat tre olika portföljer, med tio aktier i varje vilka representerar de minst, mitterst och mest likvida aktierna enligt vårt valda likviditetsmått, aktieomsättningshastighet. Likviditetsmåttet laggar en månad för att kunna användas som investeringsstrategi. Vi har studerat portföljernas värdeutveckling under perioden september 2003 till december 2011 för att se om portföljernas olika likviditet påverkar avkastningen. Genom regressionsanalyser där aktieomsättningshastighet, betavärde samt storleken använts som oberoende variabler har vi försökt förklara portföljernas överavkastning mot AFGX. Resultat: Vi har kommit fram till att det inte existerar någon likviditetspremie på Stockholmsbörsen under vår valda undersökningsperiod. Det samma gäller under uppåt- respektive nedåtgående marknadstrend. Det enda fallet där en mer illikvid portfölj presterar bäst är under januari månad. / Background: Earlier studies have concluded that there is a connection between a stock’s liquidity and its yield. Proof of this connection has mainly been found on foreign stock exchanges. On the Swedish stock market, earlier studies have concluded that this connection may not exist. The authors therefore intend to do a liquidity study on the Swedish stock market on a partly new time period to see whether this liquidity premium exists or not. Aim: The aim with this study is to investigate if there is a possibility to achieve a higher yield by investing in a portfolio consisting of relatively illiquid stocks contrary a portfolio with highly liquid stocks. We also want to investigate if the factors: liquidity, beta value and company size have a significant impact on the portfolios possible excess return in relation to an appropriate index. Completion: In this study, the authors have constructed three different portfolios consisting of ten stocks, each which represent the least, middle, and highest liquid stocks according to our liquidity measure. This measure has a one-month lag to make it possible to use as an active investment strategy. The authors have studied the portfolios growth during the period September 2003 to December 2011 to investigate if the difference in liquidity has any impact on the return. Through regression analysis, where stock turnover ratio, beta value and company size has been used as independent variables, the study tries to explain the portfolios excess return over the AFGX index. Results: The study concludes that there is no significant liquidity premium during our chosen time period. The same conclusion is drawn on the sub-periods with both an up going and down going market trend. The only period during which an illiquid portfolio outperforms a liquid portfolio is during the month of January.
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Design of a Generalized Predictive Controller for Hydrogen Supply on a PEM Fuel CellDai, Liang-Yu 04 October 2011 (has links)
This thesis proposes an adaptive control approach to regulate the hydrogen feed of a fuel cell. The goal of the controller is to maintain the so-called hydrogen excess ratio, defined as the ratio between the hydrogen fed to the cell stake and those consumed in the stake, at a desired level when the fuel cell is under load variation. Maintaining the hydrogen excess ratio
at an appropriate level would avoid hydrogen starvation, which is crucial for slowing degeneration of the fuel cell membranes and prolonging the life of the cell stake.
The control approach we propose is based on the receding horizon linear quadratic optimal control algorithm with an on-line turning scheme which updates the plant model according to real-time measurement. To ease the computational complexity and make real-time turning realizable, we adopt a simple autoregressive with external disturbance (ARX) model to approximate the complicate chemical/electrical process of the fuel cell. The proposed adaptive control approach is implemented
on an experimental platform. The experimental results show that the proposed control works with reasonably good performance.
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System Design of a Wide Bandwidth Continuous-Time Sigma-Delta ModulatorPeriasamy, Vijayaramalingam 2010 May 1900 (has links)
Sigma-delta analog-to-digital converters are gaining in popularity in recent times because of their ability to trade-off resolutions in the time and voltage domains. In particular, continuous-time modulators are finding more acceptance at higher bandwidths due to the additional advantages they provide, such as better power efficiency and inherent anti-aliasing filtering, compared to their discrete-time counterparts. This thesis work presents the system level design of a continuous-time low-pass sigma-delta modulator targeting 11 bits of resolution over 100MHz signal bandwidth. The design considerations and tradeoffs involved at the system level are presented. The individual building blocks in the modulators are modeled with non-idealities and specifications for the various blocks are obtained in detail. Simulation results obtained from behavioral models of the system in MATLAB and Cadence environment show that a signal-to-noise-and-distortion-ratio (SNDR) of 69.6dB is achieved. A loop filter composed of passive LC sections is utilized in place of integrators or resonators used in traditional modulator implementations. Gain in the forward signal path is realized using active circuits based on simple transconductance stages. A novel method to compensate for excess delay in the loop without using an extra summing amplifier is proposed.
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Did bowhead whales (Balaena mysticetus) from the Bering-Chukchi-Beaufort Seas undergo a genetic bottleneck? A test using nuclear microsatellite lociHunter, Devra Denise 01 November 2005 (has links)
This study reexamines the nuclear microsatellite analysis by Rooney et al. (1999a) of Bering-Chukchi-Beaufort Seas bowhead whales (Balaena mysticetus) to determine if this population underwent a genetic bottleneck as a result of 19th and early 20th Century commercial whaling. This investigation used more accurate laboratory techniques to score alleles, had a larger sample size that was divided into two groups (mainland Alaska and St. Lawrence Island (SLI)), and used a moderately different set of microsatellite loci which are more variable and thus, more informative. The results corroborate the findings of Rooney et al. (1999a) for mainland Alaska showing no evidence of a genetic bottleneck. However, the SLI data analyses provide conflicting conclusions. The Wilcoxon test is significant for a heterozygote excess (p = 0.042) suggesting that a genetic bottleneck has occurred. This is not substantiated by the exact tests of each locus or the table-wide sign test. There is a possibility that a bottleneck has occurred, but due to the small sample size this is not a definitive conclusion and warrants reanalysis with a larger sample size.
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Performance of Actively Managed Equity Mutual Funds : Empirical Evidence of the Swedish MarketDijokas, Paulius, Zaric, Dijana January 2015 (has links)
During the last decade, investments into the Swedish mutual fund market have increased substantially. The increased popularity of actively managed Swedish equity funds among households and investment companies, correspondingly, funds need to deliver substantial results, raised the importance to evaluate these funds’ performance. This thesis adds to the scarce empirical literature on Swedish equity mutual fund performance. Employing the Fama-French three factor model, it analyzes whether actively managed Swedish equity mu- tual funds outperform the Fama-French benchmarks net- and gross of management fees. The study uses time-series data and constructs equally-weighted portfolios of the 42 Swe- dish based actively managed equity mutual funds investing in Sweden for the period 2003- 2013. The portfolios’ excess returns are calculated by estimating the Fama-French three factor model by means of ordinary least squares (OLS) regression analysis. The empirical results show that actively managed equity mutual funds over performed the Fama-French three factor benchmarks by an average annualized net- and gross excess return of 3.60 and 4.67 percent respectively. Sorting out the funds by the performance into deciles, the find- ings indicate that management fees influence the performance of the equity mutual funds in the sample of our study. The conclusion is made such that there is an indication that Swedish equity funds’ managers are able to add value above passive investing.
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Development of optical sensing protocols for the rapid determination of enantiomeric excess in high-throughput screeningLeung, Diana 27 June 2012 (has links)
Asymmetric synthesis has become an important tool to prepare enantiomerically pure compounds because it avoids the wasteful discarding of the undesired enantiomer. Combinatorial libraries allow for much faster screening for new and better asymmetric catalysts/auxiliaries, but they generate a large number of samples whose enantiomeric excess (ee) cannot be determined rapidly. This bottleneck currently limits the applicability of such approaches. We propose here the use of faster optical techniques for the determination of ee using common instrumentation, such as UV-vis spectrophotometers, and circular dichroism (CD) spectrophotometers. Our methods are easily transitioned to the microwell format commonly used in parallel/combinatorial chemistry endeavors, just by using common microplate readers: this allows for an even more rapid analysis of samples and a seamless integration in a high-throughput workflow.
We have shown that enantioselective indicator displacement assays can be developed to determine ee in a high-throughput fashion utilizing either a UV-vis spectrophotometer or a 96-well plate reader. Two chiral receptors and a commercial pH indicator were used to enantioselectively discriminate α-amino acids by monitoring the degree of indicator displacement. The two receptors were able to enantioselectively discriminate 13 of the 17 analyzed α-amino acids and accurately determine ee values of independent test samples with the use of ee calibration curves. Moreover, a sample of valine was synthesized through an asymmetric reaction, whose ee was then determined with our assay and compared to chiral HPLC and 1H NMR chiral shift reagent analysis, with excellent correlation. An artificial neural network was also successfully employed in the analyses, as an alternative to ee calibration curves. Both techniques consistently produced results accurate enough for preliminary determination of ee in a rapid manner, allowing for high throughput screening (HTS) of asymmetric reactions.
The use of circular dichroism spectroscopy with chiral BINAP was also explored to enantioselectively discriminate α-chiral ketones. The ketones were derivatized with pyridyl hydrazines to produce hydrazones, which were then bound to enantiomerically pure [Cu(I)(BINAP)]+, forming diastereomeric complexes with differential steric interactions leading to different degrees of twist in the BINAP moiety and characteristic signatures in the CD spectrum, as a function of sample ee. / text
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Notions of Dependence with Applications in Insurance and FinanceWei, Wei January 2013 (has links)
Many insurance and finance activities involve multiple risks. Dependence structures between different risks play an important role in both theoretical models and practical applications. However, stochastic and actuarial models with dependence are very challenging research topics. In most literature, only special dependence structures have been considered. However, most existing special dependence structures can be integrated into more-general contexts. This thesis is motivated by the desire to develop more-general dependence structures and to consider their applications.
This thesis systematically studies different dependence notions and explores their applications in the fields of insurance and finance. It contributes to the current literature in the following three main respects. First, it introduces some dependence notions to actuarial science and initiates a new approach to studying optimal reinsurance problems. Second, it proposes new notions of dependence and provides a general context for the studies of optimal allocation problems in insurance and finance. Third, it builds the connections between copulas and the proposed dependence notions, thus enabling the constructions of the proposed dependence structures and enhancing their applicability in practice.
The results derived in the thesis not only unify and generalize the existing studies of optimization problems in insurance and finance, but also admit promising applications in other fields, such as operations research and risk management.
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FORESTS FULL OF BEASTS: ARISTOTELIAN ANALYSES OF ANTINOMIAN MADNESS IN 'KING LEAR' AND 'TIMON OF ATHENS'Poley, Danen 23 August 2012 (has links)
"Forests Full of Beasts" analyzes late-Shakespearean thought as represented in "Timon of Athens" and "King Lear," focusing on expressions of madness. Applying an Aristotelian framework, each chapter examines the two plays through a different lens, applying the "Nicomachean Ethics," "Politics" and "Poetics" in turn. Looking at these plays through the "Ethic"s shows that Timon and Lear miss the mark of happiness through excessive action, and their madness is therefore construed as deliberately maintaining unsustainable behaviour. The Politics foregrounds humanity's social nature, and it is in their rejection of society's provisions and friendship that Timon and Lear are seen to be most mad. Following the Poetics' prioritization of plot, both plays are analyzed in terms of the unified whole, and their madness is seen as seamlessly interwoven with the overall action. The conclusion ties these analyses together, understanding Timon's and Lear's madness as the deliberate choice to pursue excessive, antisocial behaviour.
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