The primary objective of this research is to use the benefits offered by computerized three dimensional graphics and apply those to the field of human computer interaction. Focussing primarily on the interactive content of the 3D world, this research describes a range of innovative new interface elements demonstrating specific new 3Dinterfaces/components designed to provide a new interactive 3D method for handling a range of particular common real-world tasks (ranging from simple value setting tasks up to larger scale systems for browsing structured sets of hierarchical data). These systems incorporate new design concepts such as active 3D interfaces that present their data to the user rather than statically waiting for the user to interact with them (these systems prove particularly useful in the presentation of large sets of data). Overall this set of components introduces a range of new interface styles that prove very effective in many mainstream real world tasks.In addition to the development of these systems, this project demonstrates a new high level 3D interface development tool designed to simplify the challenge of constructing interactive 3D user interfaces and in doing so make 3D interface development available to a wider developer base. By constructing the components mentioned above in a structured generic form, this combination of a new development tool and a range of re-usable components provide a strong development platform, from which more complex interactive 3D interfaces can be constructed.In essence the core idea that underlies this research is making the construction of interactive and functional 3D interfaces simpler to undertake (by developing effective re-usable components to handle mainstream tasks) while at the same time generating resulting 3D interfaces that are more effective and more capable of providing users with an enjoyable and functional 3D working environment.

Current models of visual spatial attention are based on the extent to which attention can be allocated in 2-dimensional displays. The distribution of attention in 3-dimensional space has received little consideration. A series of experiments were devised to explore the apparent inconsistencies in the literature pertaining to the allocation of spatial attention in the third dimension. A review of the literature attributed these inconsistencies to differences and limitations in the various methodologies employed, in addition to the use of differing attentional paradigms. An initial aim of this thesis was to develop a highly controlled novel adaptation of the conventional robust covert orienting of visual attention task (COVAT) in depth defined by either binocular (stereoscopic) or monocular cues. The results indicated that attentional selection in the COVAT is not allocated within a 3-dimensional representation of space. Consequently, an alternative measure of spatial attention in depth, the overlay interference task, was successfully validated in a different stereoscopic depth environment and then manipulated to further examine the allocation of attention in depth. Findings from the overlay interference experiments indicated that attentional selection is based on a representation that includes depth information, but only when an additional feature can aid 3D selection. Collectively, the results suggest a dissociation between two paradigms that are both purported to be measures of spatial attention. There appears to be a further dissociation between 2-dimensional and 3-dimensional attentional selection in both paradigms for different reasons. These behavioural results, combined with recent electrophysiological evidence suggest that the temporal constraints of the 3D COVAT paradigm result in early selection based predominantly on retinotopic spatial coordinates prior to the complete construction of a 3-dimensional representation. Task requirements of the 3D overlay interference paradigm, on the other hand, while not being restricted by temporal constraints, demand that attentional selection occurs later, after the construction of a 3-dimensional representation, but only with the guidance of a secondary feature. Regardless of whether attentional selection occurs early or late, however, some component of selection appears to be based on viewer-centred spatial coordinates.

Typescript (Photocopy) / Bibliography: leaves 243-284 / 284 leaves : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (M.D.)--Dept. of Surgery, University of Adelaide, Dept. of Surgery, 1992

歯科基礎医学会, 金子 知生 = Tomoo Kaneko, 歯に矯正力を加えた際の圧迫側歯周組織の三次元的様相について = Three-dimensional situation of periodontal tissue at pressure side incident to orthodontic tooth movement, 歯科基礎医学会雑誌, 36(2), APR 1994, pp.170-186 / Hokkaido University (北海道大学) / 博士 / 歯学

<p>A common technique to evaluate load paths in complex structures is to perform FE-calculations with relative large elements. This procedure gives no information regarding stress concentrations at e.g. holes or radius but this phenomenon can later on be investigated in details with local individual submodels. Displacements is taken from the global model and used to analyse stress concentrations and crack driving parameters in the submodel.</p><p>Today, the crack controlling stress intensity factors are in general cases obtained from handbook solutions of elementary cases. This method requires engineering judgements in a conservative manner and one way to improve the solution is to model the crack in its correct surroundings in a local three-dimensional submodel.</p><p>This master thesis is focused on the development of an automated support for analysing three-dimensional cracks in submodels. The results from a global Nastran model can be imported to Trinitas and used for a more accurate stress and fatigue life analysis in a local model. Here a three-dimensional crack tip subdomain can be generated inside an eight point brick volume. The crack tip subdomain is specially designed and adjusted for accurate determination of stress intensity factors along the crack front. For example, all points are adjusted with respect to the brick volume and the crack size, triangular wedge elements are applied around the crack tip, the midpoints for these elements are moved to quarter points and the crack front is curved. The crack tip subdomain is validated against several reference cases and shows sufficiently good results with respect to the stress intensity factor.</p><p>Finally, the automated crack tip subdomain generation is applied to a geometrically complex part of a main wing carry-through bulkhead of a fighter aircraft in order to show the applicability of the procedure in an industrial environment.</p>

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 143-150).

This thesis deals with receptivity mechanisms of three-dimensional, crossflow-dominated boundary layers. The receptivity of two model problems, a swept-flat-plate and a swept-wing boundary layer, is investigated by solving the parabolised stability equations (PSE) as well as by performing direct numerical simulations (DNS).Both flow cases are known to exhibit strong inflectional instabilities, the crossflow disturbances, whose excitation by external disturbances such as surface roughness or free-stream vorticity is studied. One focus is on worst-case scenarios. This involves the determination of optimal conditions, i.e. those disturbance environments yielding the largest possible response inside the boundary layer. A new method on the basis of the PSE is presented which allows to study optimal disturbances of swept-flat-plate boundary layers. These take the form of tilted streamwise vortices. While convected downstream they develop into streamwise streaks experiencing strong non-modal growth. Eventually, they turn into crossflow disturbances and undergo exponential growth. Non-modal growth is thus found to optimally excite crossflow disturbances and can be related to a receptivity mechanism of three-dimensional boundary layers. Evaluating effects of compressibility reveals that the potential for both non-modal and modal growth increases for higher Mach numbers. It is shown that wall cooling has diverse effects on disturbances of non-modal and modal nature. While destabilising the former it attenuates the growth of modal disturbances. Concave curvature on the other hand is found to be equally destabilising for both types of disturbances. The adjoint of the linearised Navier-Stokes equations is solved for a swept-wing boundary layer by means of DNS. The adjoint solution of a steady crossflow disturbance is computed in the boundary layer as well as in the free-stream upstream of the leading edge. This allows to determine receptivity to incoming free-stream disturbances and surface roughness as well as the corresponding worst-case scenarios. Upstream of a swept wing the optimal initial free-stream disturbance is found to be of streak-type which convects downstream towards the leading edge. It entrains the boundary layer a short distance downstream of the stagnation line. While minor streamwise vorticity is present the streak component is dominant all the way into the boundary layer where the optimal disturbance turns into a crossflow mode. Futher, the worst-case surface roughness is determined. It takes a wavy shape and is distributed in the chordwise direction. It is shown that, under such optimal conditions, the swept-wing boundary layer is more receptive to surface roughness than to free-stream disturbances. Another focus of this work has been the development and evaluation of tools for receptivity prediction. Both DNS and direct and adjoint solutions of the PSE are used to predict the receptivity of a swept-wing boundary layer to localised surface roughness. The configuration conforms to wind tunnel experiments performed by Saric and coworkers at the Arizona State University. Both the DNS and the PSE are found to predict receptivity amplitudes which are in excellent agreement with each other. Though the predicted disturbance amplitudes are slightly lower than experimental measurements the overall agreement with experimental results is very satisfactory. Finally, a DNS of the stabilisation of a transitional swept-wing boundary layer by means of discrete roughness elements is presented. This control approach is found to completely suppress transition to turbulence within the domain studied and confirms experimental results by Saric &amp; coworkers. / QC 20111124

QC 20100531

The objective of this research is to explore the feasibility of addressing the major performance and reliability problems or issues, such as wirelength, stress-induced carrier mobility variation, temperature, and quality trade-offs, found in three-dimensional integrated circuits (3D ICs) that use through-silicon vias (TSVs) at placement stage. Four main works that support this goal are included. In the first work, wirelength of TSV-based 3D ICs is the main focus. In the second work, stress-induced carrier mobility variation in TSV-based 3D ICs is examined. In the third work, temperature inside TSV-based 3D ICs is investigated. In the final work, the quality trade-offs of TSV-based 3D-IC designs are explored. In the first work, a force-directed, 3D, and gate-level placement algorithm that efficiently handles TSVs is developed. The experiments based on synthesized benchmarks indicate that the developed algorithm helps generate GDSII layouts of 3D-IC designs that are optimized in terms of wirelength. In addition, the impact of TSVs on other physical aspects of 3D-IC designs is also studied by analyzing the GDSII layouts. In the second work, the model for carrier mobility variation caused by TSV and STI stresses is developed as well as the timing analysis flow considering the stresses. The impact of TSV and STI stresses on carrier mobility variation and performance of 3D ICs is studied. Furthermore, a TSV-stress-driven, force-directed, and 3D placement algorithm is developed. It exploits carrier mobility variation, caused by stress around TSVs after fabrication, to improve the timing and area objectives during placement. In addition, the impact of keep-out zone (KOZ) around TSVs on stress, carrier mobility variation, area, wirelength, and performance of 3D ICs is studied. In the third work, two temperature-aware global placement algorithms are developed. They exploit die-to-die thermal coupling in 3D ICs to improve temperature during placement. In addition, a framework used to evaluate the results from temperature-aware global placements is developed. The main component of the framework is a GDSII-level thermal analysis that considers all structures inside a TSV-based 3D IC while computing temperature. The developed placers are compared with several state-of-the-art placers published in recent literature. The experimental results indicate that the developed algorithms help improve the temperature of 3D ICs effectively. In the final work, three block-level design styles for TSV-based die-to-wafer bonded 3D ICs are discussed. Several 3D-IC layouts in the three styles are manually designed. The main difference among these layouts is the position of TSVs. Finally, the area, wirelength, timing, power, temperature, and mechanical stress of all layouts are compared to explore the trade-offs of layout quality.

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