As seismic waves travel through the earth, the visco-elasticity of the earth's medium will cause energy dissipation and waveform distortion. This phenomenon is referred to as seismic absorption or attenuation. The absorptive property of a medium can be described by a quality factor Q, which determines the energy decay and a velocity dispersion relationship. Four new ideas have been developed in this thesis to deal with the estimation and application of seismic absorption. By assuming that the amplitude spectrum of a seismic wavelet may be modeled by that of a Ricker wavelet, an analytical relation has been derived to estimate a quality factor from the seismic data peak frequency variation with time. This relation plays a central role in quality factor estimation problems. To estimate interval Q for reservoir description, a method called reflectivity guided seismic attenuation analysis is proposed. This method first estimates peak frequencies at a common midpoint location, then correlates the peak frequency with sparsely-distributed reflectivities, and finally calculates Q values from the peak frequencies at the reflectivity locations. The peak frequency is estimated from the prestack CMP gather using peak frequency variation with offset analysis which is similar to amplitude variation with offset analysis in implementation. The estimated Q section has the same layer boundaries of the acoustic impedance or other layer properties. Therefore, the seismic attenuation property obtained with the guide of reflectivity is easy to interpret for the purpose of reservoir description. To overcome the instability problem of conventional inverse Q filtering, Q compensation is formulated as a least-squares (LS) inverse problem based on statistical theory. The matrix of forward modeling is composed of time-variant wavelets. The LS de-absorption is solved by an iterative non-parametric approach. To compensate for absorption in migrated seismic sections, a refocusing technique is developed using non-stationary multi-dimensional deconvolution. A numerical method is introduced to calculate the blurring function in layered media, and a least squares inverse scheme is used to remove the blurring effect in order to refocus the migrated image. This refocusing process can be used as an alternative to regular migration with absorption compensation.

Essay 1: To delegate or not to delegate to stock markets: The case of boards with related industry expertise Abstract: I examine the extent to which boards with expertise in related product markets, i.e., downstream (customer) or upstream (supplier) industries, delegate their monitoring and advisory functions to stock markets. Directors from related industries (DRIs) are argued to have greater access to information about the input and output product markets of the firm. This, in turn, is predicted to reduce the reliance on stock-based compensation, a costly mechanism, particularly for firms that depend more on information about product markets and whose stock prices are not very informative about product markets. The evidence documented in this paper is largely consistent with these predictions. A number of additional tests suggest that this evidence is not likely to be explained by the potential conflict of interests between the firm’s stockholders and DRIs. Hence, I conclude that boards with related industry expertise delegate to stock markets to an optimally lesser extent due to their informational advantages. Essay 2: Stock-based CEO compensation following conglomerate acquisitions Abstract: I examine how stock-based incentive compensation for the CEO is designed following corporate acquisitions conditional on the economic nature of the acquisition. Large acquisitions represent significant changes in the economic environment of the firm. Furthermore, these changes are more likely to occur with conglomerate acquisitions. Accordingly, implications of the two mainstream theories of incentive compensation, i.e., efficient contracting theory and agency theory, are tested separately for conglomerate acquisitions. The empirical tests generally show that stock-based compensation is employed more intensely after conglomerate acquisitions than otherwise. Overall, the results documented in this paper seem consistent with the notion that greater economic uncertainties that are likely to follow conglomerate acquisitions induce the board to rely more heavily on stock-based incentives, an external monitoring mechanism.

This thesis consists of three chapters on financial structure, managerial compensation, and product markets. The unifying theme of these chapters is to examine how the financial decisions of firms are affected by market imperfections. Chapter 1 places emphasis on the impact of internal imperfections arising from asymmetric beliefs (or behavioral biases) and agency conflicts by examining how these internal imperfections affect managerial compensation and corporate financial structure. On the other hand, Chapters 2 and 3 incorporate external market imperfections especially arising from imperfect product market competition. More specifically, these two chapters develop market equilibrium frameworks to examine how the matching market for CEOs and firms interacts with the product market to affect the distributions of CEO compensation and firm size. In Chapter 1, we develop a dynamic model to examine the effects of asymmetric beliefs of a firm's manager and blockholders regarding the profitability of the firm's projects, and differing attitudes towards their risk, on its capital structure. The firm's capital structure reflects the tradeoff between the positive incentive effects of managerial optimism that increases the manager's output and blockholders' private benefits against the negative effects of risk-sharing costs. We provide several testable implications for the effects of the degree of managerial optimism as well as permanent and transitory components of the firm's risk on different components of capital structure. In our calibration of the model, performed separately for different industries, we show that while optimism and risk have qualitatively similar effects on capital structure in different industries, their quantitative effects are significantly different. The interactive effects of asymmetric beliefs and agency conflicts could potentially explain a significant portion of the substantial inter-industry variation in capital structure. Chapter 2 studies how the distributions of CEO talent and compensation vary across industries, and how product market characteristics affect these distributions. We develop a market equilibrium model that incorporates the competitive assignment of CEOs to firms in a framework in which firms engage in imperfect product market---specifically, monopolistic---competition. Using the distributions of CEO pay and firm value in each of twelve Fama-French industries, we calibrate the parameters of our structural model, and indirectly infer the unobserved distributions of CEO talent and firm quality that together determine firm output. We then conduct several counterfactual experiments using the calibrated models corresponding to each of the industries. We find that the distribution of CEO talent does, indeed, vary dramatically across industries. More importantly, contrary to the conclusions of earlier studies that abstract away from the effects of the product market (Tervio, 2008 and Gabaix and Landier, 2008), the impact of CEO talent on firm value appears to be quite significant. Our estimates of the effect of CEO talent on firm value for the industries in our sample are two orders of magnitude higher than those obtained by the aforementioned studies. Further, our estimates suggest that the compensation of CEOs is quantitatively in line with their contributions to firms. Broadly, our study shows that it is important to incorporate the product market environment in which firms operate when assessing the contributions of CEOs to firms. Chapter 3 builds a market equilibrium framework in which the CEO-firm matching process is affected by the product market. We show that under reasonable assumptions there is a unique equilibrium in which only managers with ability above a unique cutoff level are matched to firms. This very simple screening process endogenizes the distribution of active managers who match with firms. Our calibration of the model using a parametric approach, which is in contrast with the empirical analysis performed in Chapter 2, strongly supports the principle arguments on the importance of CEO talent and appropriate CEO talent levels (on average) in Chapter 2. In addition, due to the law of demand and supply, which is a key feature of the extended model, we obtain somewhat different influence of some of product market characteristics on CEO pay. Furthermore, our parametric approach allows us to draw some implications for the effects of CEO talent distribution on the market equilibrium.

All mechanical systems with moving parts are affected by friction, including industrial robots. Being able to design an accurate friction model would further increase the performance of todays robots. Friction is a complex dynamic phenomena that is constantly changing depending on the state and environment of the robot. It is therefore beneficial to update the parameters of the friction model online. An estimate of the friction will be made using the feedback control signal with the help of a feedforward control scheme in a two axis simulation setup. The friction estimate is then used for an offline identification of three friction model parameters in a static Lugre friction model. Improvements on the identification will be done by introducing some shut-off rules that will improve the estimate. The normalized least mean square method (NLMS) will then be used to update the parameters online. A simulation of friction compensation with a fixed friction model, and with an adaptive friction model will be studied. The method will also be simulated using experimental data taken from a real industrial robot.

Robotic manipulators have been introduced in industry as a form of increasing productivity. Today, there exist an interest to enlarge the application of these manipulators to outdoor environments. Forestry cranes used in the forestry industry are a clear example. A long term goal in this industry is the development of autonomous systems to increase the logging efficiency. In this thesis, we consider how to control the rotator of these cranes, which is an electro-hydraulically actuated motor, and is used to control the end ffector tool. Control system design for the rotator is a challenging task since the sensing is not available to full extent. The main reason is the harsh environment that these machines are exposed to and sensors such as encoders are very fragile and cannot be used. In this thesis we use alternative sensing devices, such as a magnetic sensor and a stereo camera. In the case of the camera we face a problem with big delay. A prediction method has been used to compute desired values. Due to various reasons certain measuring devices can not be used in the industry. We consider four cases for control system design where dfferent combinations of available sensors have been used. Initially angular position of the rotator is controlled using only the magnetic sensor. A cascade control setup is used where pressure and position are measurable, first using the magnetic sensor and later using the camera. When only pressure measurements are available identified models have replaced sensors for position feedback. All tests and experiments have been done using a scaled version of a real forestry crane. The available crane has similar configuration and dynamics as the real one and is therefor useful for experimental purposes.

This thesis consider enhancement of X-ray fluoroscopy image sequences. The purpose is to investigate the possibilities to improve the image enhancement in Biplanar 500, a fluoroscopy system developed by Swemac Medical Appliances, for use in orthopedic surgery. An algorithm based on recursive filtering, for temporal noise suppression, and motion compensation, for avoidance of motion artifacts, is developed and tested on image sequences from the system. The motion compensation is done both globally, by using the theory of the shift theorem, and locally, by subtracting consecutive frames. Also a new type of contrast adjustment is presented, received with an unlinear mapping function. The result is a noise reduced image sequence that shows no blurring effects upon motion. A brief study of the result shows, that both the image sequences with this algorithm applied and the contrast adjusted images are preferred by orthopedists compared to the present images in the system.

Environmental sustainability in Sweden is challenged by rising greenhouse gas emissions from transportation, input-intensive agriculture and potentially unsustainable removal of organic material from forests and farmland. The Swedish government is working towards sixteen environmental quality objectives in order to overcome these problems, among others.  The past decade gave rise to an international research community dedicated to investigate the age-old practice of applying charcoal to soil, practiced most notably by ancient civilisations in the Amazon region of South America. The high level of interest and controversy around this subject inspired this investigation of biochar’s potential benefits in Sweden.  A scientific study was conducted to examine the potential of biochar to enhance environmental sustainability in Sweden. This was largely a desk study, supplemented by expert interviews, GIS map work, an experiment and mathematical analysis.  It was found that there was insufficient research to date to prove the agronomic benefits of biochar in Sweden. More field studies are required to build up the evidence of its potential. Furthermore, as the rate of mineralization of the carbon content is dependent on numerous factors, including the composition of the soil to which the biochar is applied, it is difficult to conclusively define biochar’s carbon storage potential.  This study adds to the existing body of knowledge on the subject by integrating the conclusions from a variety of studies and expert opinions, as well as by providing maps indicating land areas in Sweden that would be likely to benefit from biochar application.

The resistor ladder (R/2R) digital-to-analogue converter (DAC) architecture is often used in high performance audio solutions due to its low-noise performance. Even high-end R/2R DACs suffer from static nonlinearity distortions. It was suspected that compensating for these nonlinearities would be possible. It was also suspected that this could improve audio quality in audio systems using R/2R DACs for digital-to-analogue (A/D) conversion. Through the use of models of the resistor ladder architecture a way of characterizing and measuring the faults in the R/2R DAC was created. A compensation algorithm was developed in order to compensate for the nonlinearities. The performance of the algorithm was simulated and an implementation of it was evaluated using an audio evaluation instrument. The results presented show that it is possible to increase linearity in R/2R DACs by compensating for static nonlinearity distortions. The increase in linearity can be quite significant and audible for the trained ear.

In a conventional charge-pump based PLL design, the loop parameters such as the band-width, jitter performance, charge-pump current, pull-in range among others govern the ar-chitecture and implementation details of the PLL. Different loop parameter specificationschange with a change in the reference frequency and inmost cases, requires careful re-designof some of the PLL blocks. This thesis describes the implementation of a semi-digital PLLfor high bandwidth applications, which is self-compensated, low-power and exhibits band-width tracking for all reference frequencies between 40 MHz and 1.6 GHz in 65nm CMOStechnology.This design can be used for a wide range of reference frequencies without redesigning anyblock. The bandwidth can be fixed to some fraction of the reference frequency during designtime. In this thesis, the PLL is designed to make the bandwidth track 5% of the referencefrequency. Since this PLL is self-compensated, the PLL performance and the bandwidthremains same over PVT corners.

This thesis discusses non-linearities associated with a sampling switch and compares transmission gate, bootstrapping and bulk-effect compensation architectures at circuit level from linearity point of view for 0.35 um CMOS process. All switch architectures have been discussed and designed with an additional constraint of switch reliability. Results indicate that for a specified supply of 3.3 Volts, bulk-effect compensation does not improve third-order harmonic distortion significantly which defines the upper most limit on linearity for a differential topology. However, for low-voltage operations bulk-effect compensation improves third-order harmonic noticeably.