<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1998, Härtill 4 uppsatser.</p> / digitalisering@umu

Classical homological algebra is done in a category of modules beginning with the study of projective and injective modules. This dissertation investigates analogous notions of projectivity and injectivity in a category of filtered modules. This category is similar to one studied by Sjödin, Nǎstǎsescu, and Van Oystaeyen. In particular, projective and injective objects with respect to the restricted class of strict morphisms are defined and characterized. Additionally, an analogue to the injective envelope is discussed with examples showing how this differs from the usual notion of an injective envelope.

This dissertation demonstrates a procedure to view any quasitoric manifold as a “minimal” sub-manifold of an ambient quasitoric manifold of codimension two via the wedge construction applied to the quotient polytope. These we term wedge quasitoric manifolds. We prove existence utilizing a construction on the quotient polytope and characteristic matrix and demonstrate conditions allowing the base manifold to be viewed as dual to the first Chern class of the wedge manifold. Such dualization allows calculations of KO characteristic classes as in the work of Ochanine and Fast. We also examine the Todd genus as it relates to two types of wedge quasitoric manifolds. Background matter on polytopes and toric topology, as well as spin and complex cobordism are provided.

Projectively textured models are used in an increasingly large number of applicationsthat dynamically combine images with a simple geometric surface in a viewpoint dependentway. These models can provide visual fidelity while retaining the effects affordedby geometric approximation such as shadow casting and accurate perspective distortion.However, the number of stored views can be quite large and novel views must be synthesizedduring the rendering process because no single view may correctly texture the entireobject surface. This work introduces the Master Texture encoding and demonstrates thatthe encoding increases the utility of projectively textured objects by reducing render-timeoperations. Encoding involves three steps; 1) all image regions that correspond to the samegeometric mesh element are extracted and warped to a facet of uniform size and shape,2) an efficient packing of these facets into a new Master Texture image is computed, and3) the visibility of each pixel in the new Master Texture data is guaranteed using a simplealgorithm to discard occluded pixels in each view. Because the encoding implicitly representsthe multi-view geometry of the multiple images, a single texture mesh is sufficientto render the view-dependent model. More importantly, every Master Texture image cancorrectly texture the entire surface of the object, removing expensive computations suchas visibility analysis from the rendering algorithm. A benefit of this encoding is the supportfor pixel-wise view synthesis. The utility of pixel-wise view synthesis is demonstratedwith a real-time Master Texture encoded VDTM application. Pixel-wise synthesis is alsodemonstrated with an algorithm that distills a set of Master Texture images to a singleview-independent Master Texture image.

In this thesis, autopilots are developed for missiles with moderate dynamics and stationary targets. The aim is to use the designs in real applications. Since the real missile model is nonlinear, a linearization process is required to get use of systematic linear controller design techniques. In the scope of this thesis, the linear quadratic full state feedback approach is applied for developing missile autopilots. However, the limitations of measurement systems on the missiles restrict the availability of all the states required for feedback. Because of this fact, the linear quadratic design will be approximated by the use of projective control theory. This method enables the designer to use preferably static feedback or if necessary a controller plus a low order compensator combination to approximate the full state feedback reference. Autopilots are checked for the validity of linearization, robust stability against aerodynamic, mechanical and measurement uncertainties.

This is an attempt to understand the interaction of meanings of brand identity and &amp / #8216 / designed&amp / #8217 / product from the consumers&amp / #8217 / viewpoint. Brand Identity is taken as the &amp / #8216 / conceived&amp / #8217 / identity, which overlaps with concepts of brand image and brand associations. &amp / #8216 / Designed&amp / #8217 / product is analyzed via dimensions of function, form (aesthetic) and symbol. The aim of the thesis is to find patterns of interaction of functional, emotive and symbolic associations for brand identity and the functional, formal (aesthetic) and symbolic communication of the &amp / #8216 / designed&amp / #8217 / product. A qualitative research paradigm is followed in the thesis, given the emphasis on consumer-constructed meanings. Projective tasks based on dummy models and word associations are used as research tools. The product group included in the study is mobile phones because of high awareness levels and wide interest of the consumers. The context of the interaction is constrained by the nature of product group (fashion and high-tech item) as well as the properties of brands used in the study (Nokia, Motorola and Samsung).

[Truncated abstract]The overall aim of the research reported in this thesis was to develop and validate an instrument that would identify children among the general population at risk of self-harm. To achieve this, four separate yet interrelated studies were conducted. Study One, which sought to explore the risk factors of self-harm in children comprised a series of focus interviews with three paediatricians and 24 mothers of children who had self-harmed or who had verbalized self-harm ideation. The findings revealed that prior to the onset of self-harming or self-harm ideation these children reportedly manifested other problem behaviours that prompted their mothers to seek specialist advice from a paediatrician. The majority of these problem behaviours were characteristic of externalizing problems, either in the form of conduct problems, aggressive behaviours or impulsiveness. Conversely, some problem behaviours were characteristic of internalizing problems such as anxiety and depression. These findings provided valuable information which in addition to the current literature created the conceptual framework for the subsequent studies. Study Two incorporated the information obtained from Study One, along with that obtained from a review of existing instruments that measure self-harm or suicide, to develop a new instrument specifically designed to assess the risk of children in the general population developing self-harming behaviours. Initially, 159 items were generated and using the extant knowledge regarding the risk factors of self-harm as a guide, the items were categorized into risk factors of anxiety, depression, low self- ii worth, social difficulty, social withdrawal, helplessness, hopelessness, atypical cognition, emotional lability, impulsivity, self-harming ideation and self-harm. ... Study Four comprised four interrelated investigations, the purposes of which were to (i) examine the prevalence rates of self-harming ideation and self-harm among young school aged children in the general population; (ii) investigate differences of risk of self-harm between the referred group and community comparison group; (iii) examine the relationship between impulsivity and risk of self-harm in these children and, (iv) examine the relationship between executive function and risk of self-harm among these children. The results from these investigations revealed that approximately 3.5% of children aged between 6 to12 years in the general population manifest self-harming ideations and approximately 2.5% actually self-harm. No significant age or gender differences were found. Children that presented with a higher level of risk of self-harm also presented with a complex array of internalizing and externalizing problem behaviours. Furthermore, children who displayed significantly higher levels of hyperactive-impulsive symptomatology scored higher on the SHRAC instrument, as did the children who had higher levels of executive functioning impairment. The findings are discussed and interpreted in line with the current research literature and are used to make suggestions for future research.

Thesis (Ph.D.)--University of Western Australia, 2007.

Thesis (MA (SW Play Therapy))--University of Pretoria, 2003. / Includes bibliographical references.

Thesis (MCom)--Universiteit van Stellenbosch, 1962. / No abstract available