The thesis applies the ICC tecniques to the probabilistic polinomial complexity classes in order to get an implicit characterization of them. The main contribution lays on the implicit characterization of PP (which stands for Probabilistic Polynomial Time) class, showing a syntactical characterisation of PP and a static complexity analyser able to recognise if an imperative program computes in Probabilistic Polynomial Time. The thesis is divided in two parts. The first part focuses on solving the problem by creating a prototype of functional language (a probabilistic variation of lambda calculus with bounded recursion) that is sound and complete respect to Probabilistic Prolynomial Time. The second part, instead, reverses the problem and develops a feasible way to verify if a program, written with a prototype of imperative programming language, is running in Probabilistic polynomial time or not. This thesis would characterise itself as one of the first step for Implicit Computational Complexity over probabilistic classes. There are still open hard problem to investigate and try to solve. There are a lot of theoretical aspects strongly connected with these topics and I expect that in the future there will be wide attention to ICC and probabilistic classes.

This thesis addressed non-smooth dynamics of lumped parameter systems, and was restricted to Filippov-type systems. The main objective of this thesis was twofold. Firstly, modeling aspects of Filippov-type non-smooth dynamical systems were addressed with an emphasis on the constitutive assumptions and mathematical structure behind these models. Secondly, robust algorithms were presented to obtain numerical solutions for various Filippov-type lumped parameter systems. Governing equations were written using two different mathematical approaches. The first approach was based on differential inclusions and the second approach was based on differential-algebraic equations. The differential inclusions approach is more amenable to mathematical analysis using existing mathematical tools. On the other hand, the approach based on differential-algebraic equations gives more insight into the constitutive assumptions of a chosen model and easier to obtain numerical solutions. Bingham-type models in which the force cannot be expressed in terms of kinematic variables but the kinematic variables can be expressed in terms of force were considered. Further, Coulomb friction was considered in which neither the force can be expressed in terms of kinematic variables nor the kinematic variables in terms of force. However, one can write implicit constitutive equations in terms of kinematic quantities and force. A numerical framework was set up to study such systems and the algorithm was devised. Towards the end, representative dynamical systems of practical significance were considered. The devised algorithm was implemented on these systems and the results were obtained. The results show that the setting offered by differential-algebraic equations is appropriate for studying dynamics of lumped parameter systems under implicit constitutive models.

The mass media project a thin “ideal” female body type (ideal-body media; IBM) onto young women. Sociocultural theorists propose that, through processes of internalisation and social comparison, IBM-exposure promotes negative body satisfaction and unhealthy eating behaviour. In three experiments, I investigated how IBM-exposure affected restrained eaters. Restrained eaters are women who are trying to lose weight by attempting to restrict their food intake. Previous researchers have found that restrained eaters perceive and process body-related information more readily than others do. The literature surrounding restrained eaters’ IBM-related self-evaluations and food intake is inconsistent. Some researchers have found restrained eaters to report positive self-evaluative effects and others have not. Furthermore, the majority of researchers report that viewing IBM triggers restrained eaters’ eating. However, this effect is not always replicated and this might be because restrained eaters have been identified with different restraint scales. To test this idea, I used two conceptually different dietary restraint scales throughout the current experiments: the concern for dieting subscale of the Restraint Scale (RS-CD) and the Dietary Intent Scale (DIS). Furthermore, because some researchers have argued that participants within previous (non-restraint) studies reported negative IBM-effects because they thought that they were meant to be negatively affected (i.e., demand characteristics), reducing these demands was a focus throughout the current experiments. In Study 1, demand characteristics were minimised by employing implicit outcome measures and by incorporating a two-study pre-text to separate the experimental manipulation from the explicitly measured dependent variables. Under the guise of a hunger and memory study, restrained and unrestrained eaters (N = 107) were required to concentrate on a slideshow of IBM- or Control-images for 2-minutes and complete an associated memory test (i.e., advertent attention). Restrained eaters (RS-CD and DIS) exposed to IBM reported negative effects (e.g., mood). However, IBM-exposure did not trigger their food intake in an unrelated taste test with M&Ms. I interpreted these findings alongside control theory. This is the theory that goal-related negative affect encourages increased goal-performance. I reasoned that paying advertent attention to the IBM caused goal-related negative affect, which triggered goal effort (i.e., dietary restraint). This theory was further tested in Study 2. The same manipulation was used in Study 2 (N = 268), which was touted as a study about participants’ personality and task performance. Here, I aimed to test restrained eaters’ implicit approach and avoidance tendencies toward diet and food stimuli. Therefore, a joystick lexical decision task (LDT) was used instead of a taste test. Restrained eaters’ self-evaluations (e.g., self-esteem) were not significantly affected by being in different experimental conditions. However, restrained eaters (RS-CD) in the IBM-condition avoided high-calorie food words during the LDT significantly faster than other participants did. These results (Studies 1 and 2) differed from previous research. This difference was attributed to the high level of advertent attention participants paid to the IBM in my experiments. Therefore, in Study 3, I manipulated participants’ attention levels. Participants (N = 171) were made to believe that the experimental slideshow and LDT were part of a task performance study. Although participants who were assigned to the Inadvertent- and Advertent-Attention conditions were exposed to the same slideshow (IBM- or Neutral-images), the experimenter did not ask participants in the Inadvertent-condition to focus on the slideshow. After this experimental manipulation, participants completed the joystick LDT. Subsequently, they completed a second unrelated study about personality and the five human senses (e.g., taste, touch, etcetera). All participants were randomly assigned to the taste-condition and completed a taste test. Inconsistent with my previous results, I did not obtain significant self-evaluation or LDT results. Furthermore, restrained eaters (RS-CD) who paid advertent attention to the IBM consumed more food than others consumed during the taste test. In comparison, restrained eaters were buffered from this effect if they had paid inadvertent attention to the IBM-images. When comparing these (nonsignificant and significant) results with previous research, it seems that restrained eaters’ IBM-responses are highly specific to environmental and/or experimental settings. I developed a preliminary theory to predict restrained eaters’ behaviour. This theory takes into account participants’ restraint status, restraint success, IBM-related attention and their eating-related attention.

This thesis focuses on the phenomenon of aliasing and its mitigation with two explicit filters, i.e., Shuman and Padé filters. The Shuman filter is applied to velocity components of the Navier--Stokes equations. A derivation of this filter is presented as an approximation of a 1-D “pure math” mollifier and extend this to 2D and 3D. Analysis of the truncation error and wavenumber response is conducted with a range of grid spacings, Reynolds numbers and the filter parameter, β. Plots of the relationship between optimal filter parameter β and grid spacing, L2-norm error and Reynolds number to suggest ways to predict β are also presented. In order to guarantee that the optimal β is obtained under various stationary flow conditions, the power spectral density analysis of velocity components to unequivocally identify steady, periodic and quasi-periodic behaviours in a range of Reynolds numbers between 100 and 2000 are constructed. Parameters in Pade filters need not be changed. The two filters are applied to velocities in this paper on perturbed sine waves and a lid-driven cavity. Comparison is based on execution time, error and experimental results.

BlobTree modelling has been used in several solid modelling packages to rapidly prototype models by making use of boolean and sketch-based modelling. Using these two techniques, a user can quickly create complex models as combinations of simple primitives and sketched objects. Because the BlobTree is based on continuous field-values, it offers a lot of possibilities to create and control smooth transitions between surfaces, something more complicated in other modelling approaches. In addition, the data required to describe a BlobTree is very compact. Despite these advantages, the BlobTree has not yet been integrated into state of the art industrial workflows to create models. This thesis identifies some shortcomings of the BlobTree, presents potential solutions to those problems and demonstrates an application that makes use of the BlobTree's compact representation. A main criticism is that the evaluation of a large BlobTree can be quite expensive, and, therefore, many applications are limited in the complexity of models that can be created interactively. This work presents an alternative way of traversing a BlobTree that lowers the time to calculate field-values by at least an order of magnitude. As a result, the limit of model complexity is raised for interactive modelling applications. In some domains, certain models need more than one designer or engineer to be created. Often, several iterations of a model are shared between multiple participants until it is finalized. Because the description of a BlobTree is very compact, it can be synchronized efficiently in a collaborative modelling environment. This work presents CollabBlob, an approach to collaborative modelling based on the BlobTree. CollabBlob is lock-free, and provides interactive feedback for all the participants, which helps with a fast iteration in the modelling process. In order to extend the range of models that can be created within CollabBlob, two areas of BlobTree modelling are improved in the context of this thesis. CAD modelling often makes use of a feature called filleting to add additional surface features, which could be caused by a manufacturing process. Filleting in general creates smooth transitions between surfaces, something that the BlobTree can do with less mathematical complexity than approaches needed in Constructive Solid Geometry (CSG), in the case of fillets between primitives. However, little research has been done on the construction of fillets between surfaces of a single BlobTree primitive. This work outlines Angle-Based Filleting and the Surface Fillet Curve, two solutions to improve the specification of fillets in the BlobTree. Sketch-based implicit modelling generates 3D shapes from 2D sketches by sampling the drawn shape and using the samples to create the implicit field via variational interpolation. Additional samples inside and outside the sketched shape are needed to generate a field compatible with BlobTree modelling and state of the art approaches use offset curves of the sketch to generate these samples. The approach presented in this work reduces the number of sample points, thus accelerating the interpolation time and improving the resulting implicit field. / Graduate / 0984 / herbert.grasberger@gmail.com

<p>Today's consumer mobile platforms such as Android and iOS manage large ecosystems of untrusted third-party applications. It is common for an application to request one or more types of sensitive data. Unfortunately, users have no insight into how their data is used. Given the sensitivity of the data accessible by these applications, it is paramount that mobile operating systems prevent apps from leaking it.</p><p>This dissertation shows that it is possible to improve the soundness of dynamic information-flow tracking on a mobile device without sacrificing precision, performance, or transparency. We extend the state of the art in dynamic information-flow tracking on Android and address two major limitations: quantifying implicit flow leaks in Dalvik bytecode and tracking explicit flows in native code. Our goal is to deliver seamless end-to-end taint tracking across Dalvik bytecode and native code.</p><p>We propose SpanDex, a system that quantifies implicit flow leaks in Dalvik bytecode for apps handling password data. SpanDex computes a bound of revealed tainted data by recording the control-flow dependencies and for each password character, keeps track of the possible set of values that have been inferred. We also propose TaintTrap, a taint tracking system for native code in third party apps. We explore native taint tracking performance bottlenecks and hardware acceleration techniques to improve instrumentation performance.</p> / Dissertation

Undersöker hur den berättartekniska strukturen i John Fowles roman The French Lieutenant's Woman skapar en interaktion mellan läsare och text. Syftet är att diskutera hur detta bidrar till det didaktiska budskap som romanen tycks formulera. Uppsatsen använder Shoshana Felmans teorier om överföring mellan läsare och text och Wolfgang Isers begrepp "den implicita läsaren" som verktyg för analysen.

This study is an investigation of the correlation between Grade 9 students’ self-theories of their intelligence and their tendency for intellectual engagement. Individuals have been shown to self-identify, with respect to their self-theories of intelligence as either entity theorists (who think of their own intelligence as fixed and fairly unchangeable), or incremental theorists (who think of their intelligence as malleable and able to be increased over time). Previous research has shown that individuals have a strong tendency to self-select one or the other of these theoretical frameworks. This study examined the correlation of this identification with individuals’ tendency to become intellectually engaged in their learning. Other demographic factors were also explored. A moderate correlation between students’ self-theory of their intelligence and their tendency for intellectual engagement was demonstrated. In this study, female students showed a higher proportion of an incremental self-theory of intelligence than males. Implications for educational leadership and classroom planning and instruction were explored

No description available.

Implicit surfaces offer many advantages for sketch-based modeling systems, such as blending, CSG, and a procedural object hierarchy. Free-form deformation (FFD) is also extremely useful in this context, however existing FFD approaches do not support implicit surface representations, and FFD lattice manipulation is time-consuming compared to sketch-based techniques. In this thesis, an FFD technique suitable for implicit surface representations is described. To enhance real-time feedback, the problem is split into an approximate formulation used during interactive deformation, and a more robust variational technique which preserves desirable scalar field properties. As an interface to manipulate the deformation, a sketch-based volumetric peeling interface is introduced. The user's task is to draw a curve on the surface, and pull or push the surface to the desirable position via the curve. Subsequently, the deformation is automatically defined. This technique has been implemented in a prototype implicit FFD system called Taco. Results created in Taco show that a desirable deformation can be easily achieved while preserving implicit properties.