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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Study of fibre-optic interferometric 3-D sensors and frequency-modulated laser diode interferometry

Wu, Fang January 2000 (has links)
No description available.
72

Do Investors Over-react to Patterns of Past Financial Performance Measures?

Alwathainani, Abdulaziz 01 January 2006 (has links)
The objectives of this thesis are threefold. First, this dissertation examines whether patterns (growth and consistency in growth) of firms' past financial performance influence investors' perceptions about stock values and future performance of these firms. Second, multiple estimation horizons of past performance variables (ranging from one to five years) are used to assess whether the interaction between growth patterns and measurement interval lengths of these variables influence investor expectations. Third, this thesis examines whether an intermediate price drifts (e.g. Jegadeesh and Titman [1993]) and subsequent long-horizon price reversal (e.g. DeBondt and Thaler (1985)] are manifestations of a market over-reaction as suggested in recent studies (e.g. Lee and Swaminathail [2000]).Annual data on sales, earnings, cash flow, and stock returns over various time periods from a sample of publicly traded firms listed on the NYSE, AMEX, and NASDAQ exchanges from 1983 to 1999 are used to address the research questions proposed in this thesis. The evidence provided in this study shows that low-growth firms outperform their high-growth firm counterparts across different performance variables, estimation intervals, and investment horizons except in the first post-formation year for firms ranked by their prior one-year financial growth rate (except for sales growth). These return differentials between low and high growth firms increase uniformly as more years of past financial performance added.Furthermore, when ranking firms based on the consistency of their prior financial growth rates over multiple estimation periods, this study finds that a firm consistently achieving low (high) growth rates that places it in the lowest (highest) growth 40 percent earns high (low) stock returns. The consistency in a firm's prior financial performance influences the behavior of its future stock returns, i.e. the longer the consistency of exceptionally strong (weak) performance of a firm, the greater (lower) its subsequent stock returns. However, the incremental impact of an additional year of growth consistency on future returns seems to dissipate after the third year of prior performance data, suggesting that it may not take investors longer than three years to assume that a firm's past growth will continue for many years to come. Thus, additional evidence confirming investors' prior beliefs will not lead to a significant price drift because their expectations are already reflected in market prices.First year returns for firms except SG exhibit a strong financial drift. The price drift seems to persist even with longer estimation horizons. Multiple regression analyses suggest that reported higher returns for low-growth firms is not due to risk as measured by market betas or book-to-market ratios, nor is it due to the disproportionate impact caused by relatively smaller firms. As well, the one-year-ahead size-adjusted abnormal returns are significantly and negatively related to the size-adjusted abnormal returns for years 2 through 5. This result indicates that the evidence of a price drift reported in the first post-formation year might be due to a market over-reaction, a finding consistent with results reported by Lee and Swaminathan (2000). In additional analysis, return performance for all growth portfolios for the month of January is compared to the remainder of the year. No evidence indicating that returns to these portfolios are driven by extraordinary performance of low-growth firms in the month of January.For all variables (except for past sales growth and to some degree past stock returns), the financial drift in year one return for portfolios based on prior-one year of past performance data, is significantly stronger than that reported in Chan et al. (2004). Results reported in this thesis indicate that the average abnormal return differential between low and high growth firms for the five-year estimation intervals (with exception of past sales growth) is greater than 10 percentage points. The evidence contradicts that documented in Chan et al. (2004). They find no discernable evidence of price reversals over the next 36-months after ranking firms by their five-year growth rates in sales, operating income, and net income. However, results of this study are consistent with the predictions of behavioral models (e.g. Daniel et al. [I998] and Lakonishok et al. [1994]) suggesting that investors put excessive weight on patterns of a firm's past financial performance when projecting its future prospects.
73

Development and Prototypical Implementation of a Universal Concept for a Trailer Rear View Camera

Böttger, Sören January 2016 (has links)
Manoeuvring a vehicle with additionally attached trailers is a tedious task. Albeit driver assistance systems support the driver in nearly any situation in these days, tools facilitating the manoeuvring process of extended vehicles can only rarely be found in research and especially in the market. This thesis deals with the prototypical implementation of a rear view camera parking assistance system. In particular, the visualisation of the predicted driving path of the tractor-trailer combination in the camera image is emphasised, following the representation of existing parking assistance systems for individual vehicles. A general approach is aiming at the portability of the system to nearly any kind of trailer. The superimposed guidelines are based on a state space model, which is derived on top of assumptions agreeing with results found in the literature. Due to the strong assumptions and simplifications, the model is tested in three different ways and moreover for different types of trailers. All underlying methods are described in detail and furthermore tested in several scenarios, if necessary. Special importance is attached to the comparison of the actual driven paths with their previous predictions, for which a new method has been derived, implemented and tested successfully. Beside the implementation of the guideline projection to the camera’s image, the human-machine interface is augmented by a Bird’s Eye view animation, too. A final test of the integrated system for different types of trailers shows the proper operation of the overall system during parking situations.
74

Production of a filmstrip and guide on the operation and maintenance of the viewlex projector model 22CL

Williams, Fred Earl Unknown Date (has links)
No description available.
75

Trilinear Projection

Vallance, Scott, scottvallance@internode.on.net January 2005 (has links)
In computer graphics a projection describes the mapping of scene geometry to the screen. While linear projections such as perspective and orthographic projection are common, increasing applications are being found for nonlinear projections, which do not necessarily map straight lines in the scene to straight lines on the screen. Nonlinear projections occur in reflections and refractions on curved surfaces, in art, and in visualisation. This thesis presents a new nonlinear projection technique called a trilinear projection that is based on the trilinear interpolation of surface normals used in Phong shading. Trilinear projections can be combined to represent more complicated nonlinear projections. Nonlinear projections have previously been implemented with ray tracing, where rays are generated by the nonlinear projections and traced into the scene. However for performance reasons, most current graphics software uses scanline rendering, where a scene point is imaged on a screen as a function of the projection parameters. The techniques developed in this thesis are of this nature. This thesis presents several algorithms used in trilinear projection: 1. An algorithm to analytically determine which screen locations image a given scene point. 2. An algorithm that correctly connects projected vertices. Each scene point may be imaged multiple times, which means a projected scene triangle may form from one to four different shapes of from two to nine vertices. Once connected, the projected shapes may be rendered with standard scanline algorithms. 3. An algorithm to more accurately render the curved edges between projected vertices. 4. A scene-space edge-clipping algorithm that handles continuity issues for projected shapes across composite projections. The trilinear projection technique is demonstrated in two different application areas: visualisation, and reflections and refractions. Specifically, various nonlinear projections that are congruent with pre-existing visualisation techniques are implemented with trilinear projections and a method for approximating the reflections and refractions on curved surfaces with trilinear projections is presented. Finally, the performance characteristics of the trilinear projection is explored over various parameter ranges and compared with a naive ray tracing approach.
76

Fast Factorized Back-Pro jection in an FPGA

Hast, Andreas, Johansson, Lars January 2006 (has links)
<p>The Fast Factorized Back Pro jection (FFBP) algorithm is a computationally efficient </p><p>algorithm for image formation in a Very High Frequency Synthetic Aperture Radar (VHF </p><p>SAR) system. In this report an investigation of the feasibility of using an FPGA with a </p><p>hard CPU core to calculate the FFBP in real-time has been done. Two System on a Chip </p><p>designs for this task have been proposed for calculating the FFBP. A simplified version of </p><p>the FFBP has also been implemented in Matlab and used during this pro ject. The result </p><p>is that the computationally intensive parts, such as index generating and interpolation </p><p>calculations, should be implemented in the logic part of the FPGA and the CPU should </p><p>handle scheduling. This kind of modular system is easy to maintain and upgrade.</p>
77

Perspective Projection Invariants

Verri, Alessandro, Yuille, Alan 01 February 1986 (has links)
An important part of stereo vision consists of finding and matching points in two images which correspond to the same physical element in the scene. We show that zeros of curvature of curves are perspective projection invariants and can therefore be used to find corresponding points. They can be used to help solve the registration problem (Longuet-Higgins, 1982) and to obtain the correct depth when a curve enters the forbidden zone (Krol and van de Grind, 1982). They are also relevant to theories for representing image curves. We consider the stability of these zeros of curvature.
78

Video Installation Design: Appropriation and Assemblage As Projection Surface Geometry

Weaver, Timothy A. 2010 May 1900 (has links)
This area of research focuses on the use of video projections in the context of fine art. Emphasis is placed on creating a unique video installation work that incorporates assemblage and appropriation as a means to develop multiple complex geometrical surfaces for video projection. The purpose of this research is to document a working process within a pre-defined set of guidelines that is influenced from my past work and the study of other artist?s prior work. Research includes the demonstration of the entire working process to create this original work and recommendations for future artists who wish to work in this medium.
79

Fast Factorized Back-Pro jection in an FPGA

Hast, Andreas, Johansson, Lars January 2006 (has links)
The Fast Factorized Back Pro jection (FFBP) algorithm is a computationally efficient algorithm for image formation in a Very High Frequency Synthetic Aperture Radar (VHF SAR) system. In this report an investigation of the feasibility of using an FPGA with a hard CPU core to calculate the FFBP in real-time has been done. Two System on a Chip designs for this task have been proposed for calculating the FFBP. A simplified version of the FFBP has also been implemented in Matlab and used during this pro ject. The result is that the computationally intensive parts, such as index generating and interpolation calculations, should be implemented in the logic part of the FPGA and the CPU should handle scheduling. This kind of modular system is easy to maintain and upgrade.
80

Video Installation Design: Appropriation and Assemblage As Projection Surface Geometry

Weaver, Timothy A. 2010 May 1900 (has links)
This area of research focuses on the use of video projections in the context of fine art. Emphasis is placed on creating a unique video installation work that incorporates assemblage and appropriation as a means to develop multiple complex geometrical surfaces for video projection. The purpose of this research is to document a working process within a pre-defined set of guidelines that is influenced from my past work and the study of other artist?s prior work. Research includes the demonstration of the entire working process to create this original work and recommendations for future artists who wish to work in this medium.

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