This Dissertation consists of two essays. The first essay studies the causal impacts of compensation disclosure on executive compensation, turnover, and executives’ job responsibilities. We find that, after the SEC mandates the disclosure of Chief Financial Officers (CFOs)’ compensation in 2006, CFO pay increases significantly relative to CEO pay, particularly in firms most affected by the mandate. CFOs are more likely to leave their firms following poor performance. The results are absent for the CEO or other executives, suggesting they are unique outcomes of enhanced CFO compensation disclosures. The evidence is consistent with more intense monitoring following the disclosure mandate. CFOs require additional compensation for the loss of private benefits due to greater monitoring and are subject to greater internal discipline. There is also some evidence that the CFOs hide bad news and lower corporate reporting quality after the mandate, suggesting that CFOs engage in more short-term behavior to boost their performance and avoid termination. The second essay of my dissertation focuses on the idiosyncratic volatility puzzle - the negative relation between estimated idiosyncratic volatility and the subsequent month returns documented by Ang et al (2006). We document a systematic pattern of temporary increases in the estimated idiosyncratic volatility for the quintile of stocks with the highest estimated idiosyncratic volatility in a given month. A large portion of this temporary increase in the estimated idiosyncratic volatility is reversed in the subsequent month. This temporary increase in the idiosyncratic volatility for the quintile of stocks with the highest estimated idiosyncratic volatility is associated with relatively large positive returns (positive abnormal returns) in the estimation month and relatively low returns (negative abnormal returns) in the subsequent month. Our evidence shows that these temporary increases in the estimated idiosyncratic volatility and the related positive and negative abnormal returns in the estimation and subsequent months, respectively, create a negative relation between the estimated idiosyncratic volatility and subsequent month returns documented in the prior literature (Ang et al. 2006). We find no significant relation between idiosyncratic volatility and subsequent returns for eighty percent of the stocks that do not exhibit large changes in idiosyncratic volatility despite large differences in the levels of their idiosyncratic volatility. Finally, there is no relation between the estimated idiosyncratic volatility and subsequent returns after a lag of 3 months when the abnormal returns associated with temporary changes are no longer present. Overall, our results are consistent with the notion that there is no relation between the true underlying idiosyncratic volatility and expected returns, and that the previously documented negative relation between estimated idiosyncratic volatility and subsequent month’s returns is being driven by temporary one-month increases in the estimated idiosyncratic volatility and the associated abnormal returns for a subset of stocks. / Ph. D.

Offentliga företag har fått ett större intresse av att införa Business Intelligence-lösningar. Graden av framgång varierar mellan olika typer av industrier på grund av komplexa processer som är relaterade till höga kostnader. Syftet med studien var att identifiera de kritiska framgångsfaktorerna för att framgångsrikt införa en BI-lösning ur ett CFO-perspektiv. BI har en bred kategori av olika applikationer och teknologier som används för att samla in, lagra och analysera data för att sedan extrahera den. Denna data görs sedan tillgänglig för anställda i företaget för att hjälpa beslutsfattare att skapa professionella och informerade affärsbeslut. Studien genomfördes med hjälp av en kvalitativ innehållsanalys tillsammans med semi-strukturerade intervjuer. Intervjuer genomfördes med sju olika CFO:er för att få sina perspektiv angående vilka som är de kritiska framgångsfaktorer för att införa en BI-lösning. Innehållsanalysen genererade nio kategorier med flera underkategorier. Varje kategori och underkategori identifierar CSF ur ett CFO-perspektiv. De kategorier som identifierades var: Företagsledare med genomtänkta arbetslag, hållbar datakvalitet, slutanvändaren i fokus, extern hjälp bidrar med ett bredare perspektiv och kapacitet, mål och visioner, stöd från ledningen, iterativt tillvägagångssätt, affärsdriven expansion och agila tekniska ramar, och att ha rätt förutsättningar under hela implementeringen. Både studielitteraturen, CFO:erna och CFO:ernas rankning av CSF drar slutsatsen att alla framgångsfaktorer verkligen behövs för en framgångsrik BI-lösning. Alla CSF prioriteras däremot olika inom alla tre datakällor som fanns tillgängliga för studien. / Public companies have gotten a bigger interest in implementing Business Intelligence solutions. The level of success rate varies between various types of industries because of complex processes that are related to high costs. The aim of the study was to identify the critical success factors for implementing a BI-solution successfully from a Chief Financial Officers perspective. BI has a broad category of various applications and technologies that are used to collect, store and analyze data and then extract it and make the data available to employees in the company in order to help decision makers to create professional and informed business decisions. The study was conducted using a qualitative content analysis and semi-structured interviews making use of seven different CFO’s to follow up on their perspective on organizational critical successfactors for implementing a BI-solution. The content analysis generated nine categories with several sub-categories. Each category and sub-category defining CSF from a CFO’s point of view. The categories identified were: Business leaders with well-thought-out work teams, sustainable data quality, the end user in focus, external help contributes witha broader perspective and capacity, goals and visions, management support, iterative approach, business-driven expansion and agile technical framework, and having the right conditions through out the implementation. Both the study literature, respondents and the respondents’ ranking of the CSF conclude that all success factors are indeed CSF needed for a successful BI-implementation. However, the CSF were prioritized differently within all three data sources of material that were available for the study.

This thesis presents a novel method to solve the problem of estimating the carrier frequency set in an Orthogonal Frequency Division Multiplexing (OFDM) system. The approach is based on the minimization of the probability of symbol error. Hence, this approach is called the Minimum Symbol Error Rate (MSER) approach. An existing approach based on Maximum Likelihood (ML) is chosen to benchmark the performance of the MSER-based algorithm. The MSER approach is computationally intensive. The thesis evaluates the approximations that can be made to the MSER-based objective function to make the computation tractable. A modified gradient function based on the MSER objective is developed which provides better performance characteristics than the ML-based estimator. The estimates produced by the MSER approach exhibit lower Mean Squared Error compared to the ML benchmark. The performance of MSER-based estimator is simulated with Quaternary Phase Shift Keying (QPSK) symbols, but the algorithm presented is applicable to all complex symbol constellations.

One of the challenges of distributed cooperative orthogonal frequency division multiplexing systems is that the multiple carrier frequency offsets (CFOs) simultaneously present at the receiver. According to our knowledge up to now, even the CFOs are known at the receiver, the way to perfectly eliminate the effect of CFOs is still an open problem. This thesis proposes a scheme to mitigate the effect due to multiple CFOs by using the concept of intercarrier interference self-cancellation in transitional OFDM systems, a scheme where the data are simultaneously modulated on symmetric subcarriers between two transmit antennas. Before processing FFT, two values related to CFOs are used to adjust the time-domain signal resulting in better signal-to-interference ratio in even and odd subcarriers respectively. After that, the data are combined by applying maximum ratio combining and then decoded. Simulation results are given to demonstrate the effectiveness of the proposed scheme as compared to previous scheme.

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Nous avons étudié le comportement de capteurs répartis par rétrodiffusion Brillouin dans des fibres optiques soumises à des environnements radiatifs pour la mesure de contraintes thermomécaniques. Le premier chapitre présente le besoin de mesure répartie par fibre optique pour le stockage sur site géologique des déchets radioactifs de moyennes et hautes activités vie longue (MA-VL et HA-VL) envisagé par l'Andra. Le second chapitre précise la méthodologie utilisée durant la thèse. Le choix de fibres optiques utilisées ainsi que les moyens de caractérisation exploités pour étudier l'évolution de la réponse des fibres optiques y sont présentés. Dans la troisième partie, nous montrerons l'influence de l'exposition aux rayonnements UV sur le spectre Brillouin de certaines fibres optiques. La réponse de la fibre optique fortement dopées au Germanium montre une grande sensibilité de l'atténuation et des changements sur la fréquence Brillouin induits par des rayonnements UV. Dans la quatrième partie, nous montrerons les résultats de la méthodologie appliquée pour la caractérisation de la réponse capteurs répartis par rétrodiffusion Brillouin dans diverses fibres optiques au cours des irradiations gamma. Ces études ont permis de converger vers la conception d'une fibre optique spéciale dopée au Fluor qui est adaptée l'application de surveillance d'alvéole de stockage de déchets radioactifs de type HA-VL et MA-VL pendant une échelle séculaire

Orthogonal frequency-division multiplexing (OFDM) has been adopted by many broadband wireless communication systems for the simplicity of the receiver technique to support high data rates and user mobility. However, studies also show that the advantage of OFDM over the single-carrier modulation schemes could be substantially compromised by timing or frequency estimation errors at the receiver. In this thesis we investigate the synchronization problem for practical OFDM systems using a system model generalized from the IEEE 802.11 and IEEE 802.16 standards. For preamble based synchronization schemes, which are most common in the downlink of wireless communication systems, we propose a novel timing acquisition algorithm which minimizes false alarm probability and indirectly improves correct detection probability. We then introduce a universal fractional carrier frequency offset (CFO) estimator that outperforms conventional methods at low signal to noise ratio with lower complexity. More accurate timing and frequency estimates can be obtained by our proposed frequency-domain algorithms incorporating channel knowledge. We derive four joint frequency, timing, and channel estimators with different approximations, and then propose a hybrid integer CFO estimation scheme to provide flexible performance and complexity tradeoffs. When the exact channel delay profile is unknown at the receiver, we present a successive timing estimation algorithm to solve the timing ambiguity. Both analytical and simulation results are presented to confirm the performance of the proposed methods in various realistic channel conditions. The ranging based synchronization scheme is most commonly used in the uplink of wireless communication systems. Here we propose a successive multiuser detection algorithm to mitigate multiple access interference and achieve better performance than that of conventional single-user based methods. A reduced-complexity version of the successive algorithm feasible for hardware real-time implementation is also presented in the thesis. To better understand the performance of a ranging detector from a system point of view, we develop a technique that can directly translate a detector�s missed detection probability into the maximum number of users that the method can support in one cell with a given number of ranging opportunities. The analytical results match the simulations reasonably well and show that the proposed successive algorithms allow a base station to serve more than double the number of users supported by the conventional methods. Finally, we investigate inter-carrier interference which is caused by the timevarying communication channels. We derive the bounds on the power of residual inter-carrier interference that cannot be mitigated by a frequency-domain equalizer with a given number of taps. We also propose a Turbo equalization scheme using the novel grouped Particle filter, which approaches the performance of the Maximum A Posterior algorithm with much lower complexity.

Nous avons étudié le comportement de capteurs répartis par rétrodiffusion Brillouin dans des fibres optiques soumises à des environnements radiatifs pour la mesure de contraintes thermomécaniques. Le premier chapitre présente le besoin de mesure répartie par fibre optique pour le stockage sur site géologique des déchets radioactifs de moyennes et hautes activités vie longue (MA-VL et HA-VL) envisagé par l’Andra. Le second chapitre précise la méthodologie utilisée durant la thèse. Le choix de fibres optiques utilisées ainsi que les moyens de caractérisation exploités pour étudier l’évolution de la réponse des fibres optiques y sont présentés. Dans la troisième partie, nous montrerons l’influence de l’exposition aux rayonnements UV sur le spectre Brillouin de certaines fibres optiques. La réponse de la fibre optique fortement dopées au Germanium montre une grande sensibilité de l’atténuation et des changements sur la fréquence Brillouin induits par des rayonnements UV. Dans la quatrième partie, nous montrerons les résultats de la méthodologie appliquée pour la caractérisation de la réponse capteurs répartis par rétrodiffusion Brillouin dans diverses fibres optiques au cours des irradiations gamma. Ces études ont permis de converger vers la conception d’une fibre optique spéciale dopée au Fluor qui est adaptée l’application de surveillance d’alvéole de stockage de déchets radioactifs de type HA-VL et MA-VL pendant une échelle séculaire / We studied the behavior distributed Brillouin sensor in optical fibers under radiative environments for strain and temperature measurements. The first chapter presents the need for distributed measurement by using optical fiber for the storage of radioactive waste geological site of medium and high long-lived activities (MA- VL and HA-VL) proposed by Andra. The second chapter outlines the methodology used in the thesis. The choice of fiber used and the characterization means operated to study the evolution of the response of the optical fibers are presented. In the third part, we show the influence of exposure to UV radiation on the Brillouin spectrum of several optical fibers. The response of the optical fiber highly doped with Germanium shows high sensitivity on the attenuation and the Brillouin frequency induced by UV radiation. In the fourth section, we show results from our methodology for the characterization of the response Brillouin sensors in various optical fibers during differents gamma irradiation conditions. These studies converge towards the design of a special fluorine -doped optical fiber which is suitable for the application of monitoring of the future site for the storage of radioactive waste type HA- MA- VL and VL for a century scale

Titel: Ledningens karaktärsdrag - effekten på kapitalstrukturEn studie om förhållandena mellan tre individuella chefers karaktärsdrag och företagshävstång  Bakgrund och problematisering: Här diskuteras bakgrunden till studien och enproblematisering kring chefers karaktärsdrag och dess påverkan på kapitalstruktur samt vadsom menas med dessa begrepp. Vidare tar detta kapitel upp det underliggande intresset attförklara sambandet mellan tre chefers karaktärsdrag (CEO, CFO och COO) ochkapitalstruktur. Syfte: Syftet med denna studie är att förklara effekten av individuella chefers karaktärsdragpå svenska börsnoterade företags kapitalstruktur. Metod: Företagens kapitalstruktur undersöks genom att använda en kvantitativforskningsmetod med en deduktiv forskningsansats för att identifiera förhållanden mellanchefernas karaktärsdrag och hävstång. Paneldata används från 114 svenska börsnoteradeföretag över en femårsperiod (2014-2018). Studien fann totalt 179 chefer varav 87 CEO:s, 73CFO:s och 19 COO:s. Den insamlade datan testas genom regressionsanalyser där paneldataregressioner med random effects-modellen och robusta standardfel utförs. Slutsats: Resultaten från testerna visar på både signifikanta och icke-signifikantaförhållanden mellan de tre chefernas karaktärsdrag och företagens kapitalstruktur, mätt somhävstång. Det finns därmed bevis som tyder på att olika karaktärsdrag hos individuella cheferpåverkar företags kapitalstruktur.

The purpose of this study was to analyze the characteristics of, and the perceived responsibilities of chief financial officers in California single and multi-district community colleges. This study sought to answer questions about how current CFOs in California Community Colleges perceive the necessary skills and the value of job and professional development to do their job. This study focused on three research questions: 1) What do current California Community College CFOs perceive to be necessary preparation and skills and 2) How do current California Community College CFOs acquire the skills they believe necessary to be a California Community College CFO? 3) What are the demographic characteristics of California Community College CFOs? A survey with both structured closed and open-ended questions was used to identify what 110 California Community College CFOs perceive to be the necessary preparation, skills, and professional preparation is needed to be an effective community college CFO. The majority of the community college CFOs of California are white males between the age of 50 and 59 who are likely to retire within the next ten years. Women constitute 33 percent of the CFOs; 17 percent are African American; 8.5 percent Asians; and Hispanics, the fastest growing minority group in California, made up only 1.7% of the respondents. In this study, the data showed that California's current CFOs are highly educated and bring an average of 12 years of experience to their position. They tend to work in urban, ethnically diverse Hispanic serving community colleges with average student enrollments of 15 to 20 thousand unduplicated student head count. These seasoned CFOs identified skills and on the job experiences they felt were important to being a community college CFO. The identified skills and experiences provide data that can support the development of a comprehensive mentoring, training and professional development program that closely aligns with the needs of California's community college CFOs.