A parameter-free solution is presented for data projector calibration using a single camera and Gray coded structured light patterns. The proposed method assumes that both camera and projector exhibit significant non-linear distortion, and that projection surfaces can be either planar or freeform. The camera is calibrated first through traditional methods, and the calibrated images are then used to detect Gray coded patterns displayed on a surface by the data projector. Projector to camera correspondences are created by decoding the patterns in the camera images to form a 2D correspondence map. Calibrated systems produce geometrically correct, ex- tremely short throw projections, while maintaining or exceeding the projection size of a standard configuration. Qualitative experiments are performed on two baseline images, while quantitative data is recovered from the projected image of a chessboard pattern. A typical throw ratio of 0.5 can be achieved with a pixel distance error below 1. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-06-29 09:33:50.311

The Veo+ projector is using a cooling system that consists of fan and blowers. This system is cooling the electronic components of the device and the lamp of the projector, however extracting a high noise. To lower this noise the rpm speeds (rotational speed) of the fan and blowers should be decreased. Thus, lowering the speed will result in higher temperature values in whole system (inside the device). While lowering the speed, the higher temperature values should be kept within the thermal design specifications of the electronic components. The purpose of this thesis work is to find an optimal solution with lower rpm speeds of the fan and blowers while keeping the temperatures of the various components of the device (touch temperature of the enclosure and electronic components) within the temperature design limits. Before testing the device to find the optimum state, the design limits of the device are determined. Then, by using the design of experiment methods like Taguchi, the optimum state for the device within the design specifications is obtained. Finally, additional tests are applied within the optimum state to demonstrate a fan algorithm as a final solution. While doing the experiments thermocouples are used for measuring the component temperatures.

Introduction One of the products made by SAAB Avionics Systems in Jönköping was in need of a better cooling solution. The product, a Head-Up Display, holds a LED that was overheating when run at desired input power. The purpose of this thesis was to identify the design weaknesses in the current solution regarding heat dissipation and produce new design proposals that fulfill the requirements. The parts analyzed consist of a LED light source, adjustment plates and a heat sink. The adjustment plates and heat sink where covered in a surface treatment. Theoretical framework A simulation of a finite element model was set up of the current solution in order to identify the influence of the different parts and their thermal properties. The simulation was set up as a steady state thermal model. The FEM and steady state equations used during this are mentioned and shortly explained. The state of modern research was found in order to find new innovative ways of solving the heat problem. Method In order to understand the current solution, experimentswere carried out. Interviews were used in order to get the correct information easily. A literature study was preformed to understand the different theories. Reverse engineering was applied to get a detailed understanding of the functionality both mechanically and thermally. Brainstorming was used to generate new solutions, which was followed by a feasibility evaluation and Pugh’s method to sort out the best concepts. Implementation and Result Based on the simulations it can be concluded that some of the developed solutions pass the requirements and can be implemented right away. Some need some more work in order to fully pass the demands. Conclusions The thermal flow was greatly affected by the properties of the aluminum in the adjustment plates and heat sink, though there was not much room for thickness reduction. However, the oxide layer and the surface roughness also had a great impact on the high junction temperature. The requirements where therefore met when adjustment plates and interfaces were removed, to lower the amount of oxide and air between the LED and the heat sink. But the oxide layers needed to be thinner and the surface roughness needed to be reduced in order to meet requirements. If the oxide layers need to stay at current thickness or the surface roughness cannot be changed, the heat sink needs to be redesigned. The recommended concepts were smaller than the current solution. If this space is utilized with a bigger heat sink, the goals can be met with greater ease. There is also room for improvement when it comes to heat sink heat spreader pattern. Discussion The discussion covers what knowledge which was needed to write this thesis and how different problems that occurred along its path were solved. Sustainability in different ways was also discussed.

A key feature of recent agricultural extension programs has been the focus on increased participation for local, rural communities in the overall decision-making process. This move towards increasing community participation has raised expectations in terms of communication: communication between central research facilities and rural communities, between rural communities and central research facilities, and amongst the rural communities themselves. In order to provide effective communication along each of these channels, attention is turning to the extension trainers deployed in the field. For extension trainers this emerging communication role is distinct from, and supplementary to, the conventional technical training function. The thesis highlights the lack of effective training in communication skills in existing extension training programs. It identifies the flip chart as the most widely used visual aid for farmer training, and the overhead projector as the most widely used visual aid for in-service training. The thesis develops a comprehensive set of training competencies and content for teaching those two technologies, derived from individual task analyses and an extensive literature review. A range of strategic alternatives for the delivery of those competencies in a developing country are then formulated and examined. Central to the different strategies considered is the use of interactive multimedia as a key delivery technology. Two proprietary CDROMs have been designed and produced specifically to the support training in the design and production skills for overhead projector and flip chart technologies. The design, content and production of the CDROMs is described, and both technical and user evaluations are presented. The two CDROMs have been field-tested in Sri Lanka, across a broad range of strategic alternatives. The outcome is a set of guidelines and specific structures for training programs in overhead projector and flip chart technologies. The guidelines are generic and broadly applicable. The case studies also indicate a particular subset of preferred strategies for the future deployment of interactive multimedia-based training in developing countries. Most specifically, the thesis indicates a balance between and the need for mix of interactive multimedia modules along with face-to-face training support / Doctor of Philosophy (PhD)

<p>Quantum sl_3 projectors are morphisms in Kuperberg's sl_3 spider, a diagrammatically defined category equivalent to the full pivotal subcategory of the category of (type 1) finite-dimensional representations of the quantum group U_q (sl_3 ) generated by the defining representation, which correspond to projection onto (and then inclusion from) the highest weight irreducible summand. These morphisms are interesting from a topological viewpoint as they allow the combinatorial formulation of the sl_3 tangle invariant (in which tangle components are labelled by the defining representation) to be extended to a combinatorial formulation of the invariant in which components are labelled by arbitrary finite-dimensional irreducible representations. They also allow for a combinatorial description of the SU(3) Witten-Reshetikhin-Turaev 3-manifold invariant. </p><p>There exists a categorification of the sl_3 spider, due to Morrison and Nieh, which is the natural setting for Khovanov's sl_3 link homology theory and its extension to tangles. An obvious question is whether there exist objects in this categorification which categorify the sl_3 projectors. </p><p>In this dissertation, we show that there indeed exist such "categorified projectors," constructing them as the stable limit of the complexes assigned to k-twist torus braids (suitably shifted). These complexes satisfy categorified versions of the defining relations of the (decategorified) sl_3 projectors and map to them upon taking the Grothendieck group. We use these categorified projectors to extend sl_3 Khovanov homology to a homology theory for framed links with components labeled by arbitrary finite-dimensional irreducible representations of sl_3 .</p> / Dissertation

Current high power LEDs are used popularly, energy saving can be achieved if the heat transfer performance of a high power LED is increased. Numerical analysis is carried out herein to study the parameters effect on the cooling performance for the heat sinks of the LED projector. The parameters include fin spacing, fin depth, fin thickness, base thickness and flow speed. The numerical results reveal that the parameters of the heat sinks significantly affects the average Nusselt Number. The results of this study can provide design references for LED projector.

Recent rapid development of cost-effective, accurate digital imaging sensors, high-speed computational hardware, and tractable design software has given rise to the growing field of augmented reality in the computer vision realm. The system design of a 'Digital Whiteboard' system is presented with the intention of realizing a practical, cost-effective and publicly available spatial augmented reality system. A Microsoft Kinect sensor and a PC projector coupled with a desktop computer form a type of spatial augmented reality system that creates a projection based graphical user interface that can turn any wall or planar surface into a 'Digital Whiteboard'. The system supports two kinds of user inputs consisting of depth and infra-red information. An infra-red collimated light source, like that of a laser pointer pen, serves as a stylus for user input. The user can point and shine the infra-red stylus on the selected planar region and the reflection of the infra-red light source is registered by the system using the infra-red camera of the Kinect. Using the geometric transformation between the Kinect and the projector, obtained with system calibration, the projector displays contours corresponding to the movement of the stylus on the 'Digital Whiteboard' region, according to a smooth curve fitting algorithm. The described projector-based spatial augmented reality system provides new unique possibilities for user interaction with digital content.

It is an undisputable fact that most systems, upon consistence usage are bound to fail in the performance of their intended functions at a point in time. When this occurs, various strategies are set in place to restore them back to a satisfactory performance. This may include replacing the failed component with a new one, swapping parts, resetting adjustable parts to mention but a few. Any such system is referred to as a repairable system. There is the need to study these systems and use statistical models to predict their failing time and be able to set modalities in place to repair them at least cost to the operator. The main objective of this paper is to analyze data collected on the projectors used for teaching and learning activities in some designated rooms at the Brigham Young University (BYU) under the auspices of the Office of Information Technology (OIT) and help to detect the failure rate of such systems, predict the optimal replacement time for the parts with the view of maximizing the reliability of the systems and finally formulate a cost model that will be used to estimate the optimal cost involve in servicing a failed projector.

<p> A review of movie projection principles and techniques as applied to conventional projectors and a description of general features, mechanism and film movement of the Rolling Loop Projector are presented.</p> <p> The characteristics of a film loop under static conditions with coplanar clamping planes are investigated in terms of loop shape, supporting forces and bending moments. An extension of this analysis is applicable to the case when the loop is fixed on a curved surface.</p> <p> The motion of a loop in the projector is simulated as it grows and rolls on a flat surface and a numerical technique is employed to find the point paths and the velocity and acceleration vectors of these points on the loop at various instants in a projection cycle.</p> <p> Some design criteria are derived from an examination of the results, and these are presented.</p> / Thesis / Master of Engineering (MEngr)

Cette thèse est consacrée à l'étude de la méthode PAW (projector augmented-wave) et d'une de ses modifications, baptisée méthode PAW variationnelle (VPAW), pour le calcul de l'état fondamental d'Hamiltoniens en géométrie périodique. Ces méthodes visent à améliorer la vitesse de convergence des méthodes d'ondes planes (ou méthodes de Fourier) en appliquant une transformation inversible au problème aux valeurs propres initial agissant au voisinage de chaque site atomique. Cette transformation permet de capter une partie des difficultés dues aux singularités coulombiennes. La méthode VPAW est analysée pour un opérateur de Schr\"odinger unidimensionnel avec des potentiels de Dirac. Les fonctions propres de ce modèle comprennent des sauts de dérivées similaires aux cusps électroniques. Le saut de dérivée des fonctions propres du problème aux valeurs propres issu de la méthode VPAW est réduit de façon importante. Cela entraîne une accélération de convergence en ondes planes du calcul des valeurs propres corroborée par une étude numérique. Une étude de la méthode VPAW est conduite pour des Hamiltoniens 3D périodiques avec des singularités coulombiennes, parvenant à des conclusions similaires. Pour la méthode PAW, la transformation inversible comporte des sommes infinies qui sont tronquées en pratique. Ceci introduit une erreur, qui est rarement quantifiée en pratique. Elle est analysée dans le cas de l'opérateur de Schrödinger unidimensionnel avec des potentiels de Dirac. Des bornes sur la plus basse valeur propre en fonction des paramètres PAW sont prouvées conformes aux tests numériques. / This thesis is devoted to the study of the PAW method (projector augmented-wave) and of a variant called the variational PAW method (VPAW). These methods aim to accelerate the convergence of plane-wave methods in electronic structure calculations. They rely on an invertible transformation applied to the eigenvalue problem, which acts in a neighborhood of each atomic site. The transformation captures some difficulties caused by the Coulomb singularities. The VPAW method is applied to a periodic one-dimensional Schr\"odinger operator with Dirac potentials and analyzed in this setting. Eigenfunctions of this model have derivative jumps similar to the electronic cusps. The derivative jumps of eigenfunctions of the VPAW eigenvalue problem are significantly reduced. Hence, a smaller plane-wave cut-off is required for a given accuracy level. The study of the VPAW method is also carried out for 3D periodic Hamiltonians with Coulomb singularities yielding similar results. In the PAW method, the invertible transformation has infinite sums that are truncated in practice. The induced error is analyzed in the case of the periodic one-dimensional Schrödinger operator with Dirac potentials. Error bounds on the lowest eigenvalue are proved depending on the PAW parameters.