<p>One way of modeling human knowledge is by using multidimensional spaces, in which an object is represented as a point in the space, and the distances among the points reflect the similarities among the represented objects. The distances are measured with some metric, commonly some instance of the Minkowski metric. The instances differ with the magnitude of the so-called r-parameter. The instances most commonly mentioned in the literature are the ones where r equals 1, 2 and infinity.</p><p>Cognitive scientists have found out that different metrics are suited to describe different dimensional combinations. From these findings an important distinction between integral and separable dimensions has been stated (Garner, 1974). Separable dimensions, e.g. size and form, are best described by the city-block metric, where r equals 1, and integral dimensions, such as the color dimensions, are best described by the Euclidean metric, where r equals 2. Developmental psychologists have formulated a hypothesis saying that small children perceive many dimensional combinations as integral whereas adults perceive the same combinations as separable. Thus, there seems to be a shift towards increasing separability with age or maturity.</p><p>Earlier experiments show the same phenomenon in adult short-term learning with novel stimuli. In these experiments, the stimuli were first perceived as rather integral and were then turning more separable, indicated by the Minkowski-r. This indicates a shift towards increasing separability with familiarity or skill.</p><p>This dissertation aims at investigating the generality of this phenomenon. Five similarity-rating experiments are conducted, for which the best fitting metric for the first half of the session is compared to the last half of the session. If the Minkowski-r is lower for the last half compared to the first half, it is considered to indicate increasing separability.</p><p>The conclusion is that the phenomenon of increasing separability during short-term learning cannot be found in these experiments, at least not given the operational definition of increasing separability as a function of a decreasing Minkowski-r. An alternative definition of increasing separability is suggested, where an r-value ‘retreating’ 2.0 indicates increasing separability, i.e. when the r-value of the best fitting metric for the last half of a similarity-rating session is further away from 2.0 compared to the first half of the session.</p>

<p>Ett digitalt vågfilter av Richardstyp har implementerats i en FPGA på ett utvecklingskort. Sampel kan skickas till filtret och mottas från filtret via serieporten på en dator. Metoden som användes är att en modell av filtret konstruerades i Simulink. Filtret har modifierats med avseende på skalning, brus och stabilitet. VHDL-koden till filtret genererades i Simulink genom att bygga modellen av Xilinx Blockset. Ytterligare VHDL-kod konstruerades för att kunna skicka sampel mellan filter och minnet på utvecklingskortet. För kommunikation mellan minnet på utvecklingskortet och dator utnyttjades färdiga lösningar.</p> / <p>Filtrets funktion efter implementeringen var samma som modellens byggd i Simulink. A Richards’ structure wave digital filter has been implemented on an evaluation board in an FPGA. Samples can be sent to the filter and received from the filter using the serial port of a computer. The method used is that a modell of the filter has been created in Simulink. The filter has been modified with respect to scaling, noise and stability. VHDL for the filter has been generated in Simulink by using Xilinx blockset to build the modell. Also, VHDL has been constructed to be able to send samples between the filter and the memory on the evaluationboard. For communication between the memory on the evaluationboard and the computer, existing solutions have been used. The functionality of the filter after implementation was the same as in the modell built in Simulink.</p>

<p>In this thesis two versions of a single filter frequency masking narrow-band high-speed recursive digital filter structure, proposed in [1], have been implemented and evaluated considering the maximal clock frequency, the maximal sample frequency and the power consumption. The structures were compared to a conventional filter structure, that was also implemented. The aim was to see if the proposed structure had some benefits when implemented and synthesized, not only in theory. For the synthesis standard cells from AMS csx 0.35 mm CMOS technology were used.</p>

A numerical analysis was conducted to study the effects of geometrically scaling scramjet inlet-combustor isolators. Three-dimensional fully viscous numerical simulation of the flow inside constant area rectangular ducts, with a downstream back pressure condition, was analyzed using the SolidWorks Flow Simulation software. The baseline, or 1X, isolator configuration has a 1” x 2.67” cross section and 20” length. This baseline configuration was scaled up based on the 1X configuration mass flow to 10X and 100X configurations, with ten and one hundred times the mass flow rate, respectively. The isolator aspect ratio of 2.67 was held constant for all configurations. To provide for code validation, the Flow Simulation program was first used to analyze a converging-diverging channel and a wind tunnel nozzle. The channel case was compared with analytical theory and showed good agreement. The nozzle case was compared with AFRL experimental data and showed good agreement with the entrance and exit conditions (Pi0= 40 psia, Ti0= 530ºR, Pe= 18.86 psia, Te= 456ºR, respectively). While the boundary layer thickness remained constant, the boundary layer thickness with respect to the isolator height decreased as the scale increased. For all the isolator simulations, a shock train was expected to form inside the duct. However, the flow simulation failed to generate this flow pattern, due to improper sizing of the isolator and combustor for a 3-D model or having a low pressure ratio of 2.38. Instead, a single normal shock wave was established at the same relative location within the length of each duct, approximately 80% of the duct length from the isolator entrance. The shape of the shock changed as the scale increased from a normal shock wave, to a bifurcated shock wave, and to a normal shock train, respectively for the 1X, 10X, and 100X models.

The present thesis reviews my scientific works on disordered systems from 1995 until today. They can be roughly categorized into three main classes: (1) non-interacting disordered systems, (2) the two-interacting particle problem, and (3) the interplay of disorder and many-particle interaction. A (4)th chapter is concerned with the implementation of the numerical algorithms. The structure of the thesis reflects this division. The reprints have been added at the end of these main divisions according to their context. For the convenience of the reader, I have ordered them in each chapter alphabetically according to the names of the authors. Furthermore, in each citation of my work, the starting page number in the thesis is given, e.g, Ref.\ \cite{EPR97} refers to a paper of Eckle, Punnoose and myself and can be found on page \pageref{EPR97}. Citations which do not refer to my work are numbered and are ordered in the bibliography according to the names of the authors.

Title from PDF of title page (University of Missouri--Columbia, viewed on March 10, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Thesis advisor: Dr. Lisa Flores & Dr. Craig Frisby. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 99-114).

A graphical user interface program was created along with shape models, which allow persons with disabilities to set up a stereovision system with off-the-shelf hardware and detect objects of interest, which can be picked up using a sensor assisted telerobotic manipulator. A Hitachi KP-D50 CCD camera and an Imaging Source CCD camera were used along with two Imaging Source DFG/LC1 frame grabbers to set up a stereovision system. In order to use the stereovision system, the two main problems of correspondence and reconstruction are solved using subroutines of the program created for this work.The user interface allows the user to easily perform the intrinsic and extrinsic camera calibration required for stereovision, by following a few basic steps incorporated into the user interface program, which are described in this thesis. A calibration table required for these tasks can also be easily created using the program. In order to detect the object of interest, shape models, created by the user interface program, are used to solve the correspondence problem of stereovision. The correspondence problem is that of locating corresponding points in the left eye and the right eye, which are necessary to perform the calculations to obtain the location of the object of interest with respect to the end-effector. The shape models created for some commonly available items such as a doorknob and a door handle are included in the program and used to test the stereovision system. As expected, the error of detection decreases as the stereo system is moved closer to the object of interest in the x-, y- and z-position.

The hellbender (Cryptobranchus alleganiensis) is a salamander that grows over a large range of body sizes (2-74 cm total length) making it an ideal organism for examining the effects of body size on morphology and performance. The goal of this study is to investigate the morphology changes over ontogeny and change in feeding ability. Cryptobranchus feeds on small aquatic insects as juveniles and shifts to crayfish as they get larger. Morphology can be expected to change as an organism grows larger, and because morphology and performance are closely linked, this morphological change can result in a change in feeding ability. Cryptobranchus alleganiensis are primarily aquatic salamanders that utilize both suction feeding and biting behaviors. I hypothesize bite force would increase with positive allometry reflecting a possible dietary shift during ontogeny in which larger Cryptobranchus favor crayfish. Because suction is the primary mode of feeding making it an important aspect of feeding throughout ontogeny, suction index was hypothesized to scale with isometry. Fourteen preserved specimens (11.9-34.5 cm SVL) were used to investigate the effects of scaling on suction potential and estimated bite force. Bite force was calculated using a 3D static equilibrium model and suction potential was calculated as suction index. Bite force scaled with positive allometry allowing the animals to bite harder relative to body mass with increasing body size, and suction index showed no effect of body size. Results of this study indicate that Cryptobranchus alleganiensis maintains suction performance across ontogeny allowing them to generate suction with similar ability ontogenetically, but increases its biting performance to cope with durophagous prey with a possible ontogenetic dietary shift.

This dissertation presents analytical solutions to address several unresolved issues on the modeling of CO₂ flow in permeable media. Analytical solutions are important as numerical simulations do not yield explicit expressions in terms of the model parameters. In addition, simulations that provide the most comprehensive solutions to multiphase flow problems are computationally intensive. Accordingly, we address the following topics in this dissertation. The method of characteristics (MOC) solution of the overall mass conservation equation of CO₂ in two-phase flow through permeable media is derived in the presence of compressibility. The formally developed MOC solutions rely on the incompressible fluid and rock assumptions that are rarely met in practice; hence, the incompressible assumption is relaxed and the first semi-analytic MOC solution for compressible flow is derived. The analytical solution is verified by simulation results. Fractional flow theory is applied to evaluate the CO2 storage capacity of one-dimensional (1D) saline aquifers. Lack of an accurate estimation of the CO₂ storage capacity stands in the way of the fully implementation of CO₂ storage in aquifers. The notion of optimal solvent-water-slug size is incorporated into the graphical solution of combined geochemical front propagation and fractional flow theory to determine the CO₂ storage capacity of aquifers. The analytical solution is verified by simulation results. The limits of the Walsh and Lake (WL) method to predict the performance of CO₂ injection is examined when miscibility is not achieved. The idea of an analogous first-contact miscible flood is implemented into the WL method to study miscibly-degraded simultaneous water and gas (SWAG) displacements. The simulation verifies the WL solutions. For the two-dimensional (2D) displacements, the predicted optimal SWAG ratio is accurate when the permeable medium is fairly homogeneous with a small cross-flow or heterogeneous with a large lateral correlation length (the same size or greater than the interwell spacing). We conclude that the WL solution is accurate when the mixing zone grows linearly with time. We examine decoupling of large and small-scale heterogeneity in multilayered reservoirs. In addition, using an analytical solution derived in this research, the fraction of layers in which the channeling occurs is determined as a function of the Koval factor and input dispersivity. We successfully present a simulation configuration to verify the off-diagonal elements of the numerical dispersion tensor. Numerical dispersion is inevitably introduced into the finite difference approximations of the 2D convection-dispersion equation. We show that the off-diagonal elements of the numerical dispersion tensor double when the flow velocity changes with distance. In addition, the simulation results reveal that the flow becomes more dispersive with distance travelled if there is convective cross-flow. In addition, local mixing increases with the convective cross-flow between layers. A numerical indicator is presented to describe the nature of CO₂ miscible displacements in heterogeneous permeable media. Hence, the quantitative distinction between flow patterns becomes possible despite the traditionally qualitative approach. The correlation coefficient function is adopted to assign numerical values to flow patterns. The simulation results confirm the accuracy of the descriptive flow pattern values. The order-of-one scaling analysis procedure is implemented to provide a unique set of dimensionless scaling groups of 2D SWAG displacements. The order-of-one scaling analysis is a strong mathematical approach to determine approximations that are allowed for a particular transport phenomenon. For the first time, we implement the scaling analysis of miscible displacements while considering effects of water salinity, dissolution of CO₂ in the aqueous phase, and complex configurations of injection and production wells. / text