• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 108
  • 23
  • 22
  • 10
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 231
  • 44
  • 38
  • 33
  • 31
  • 31
  • 29
  • 28
  • 26
  • 23
  • 22
  • 18
  • 18
  • 18
  • 18
  • 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.
31

Quantification of metamerism and colour constancy

Kuo, Wen-Guey January 1995 (has links)
Reliable colour constancy by industry for colour conducted to quantify metamerism. and metamerism indices are highly desired quality control. Two experiments were the degree of colour constancy and In the colour constancy experiment, 240 wool samples were prepared and scaled using a magnitude estimation method by a panel of 5 experienced observers under sources D65, A and TL84. 2 corresponding data sets derived from the experimental results were used to test various chromatic adaptation transforms. The results clearly show that the BFD transform gave the most precise prediction than the other transforms. Attempts were also made to derive 4 new transforms from four independent data sets. These gave similar performance as that of the BFD, but overcome the BFO's problem (incapable of predicting some of the high saturated colours). Hence, these transforms should be used with confidence for predicting the degree of colour constancy. This experimental results were also used to test various uniform colour spaces and colour appearance models. The Hunt94 model gave the most precise prediction to the colourfulness and hue results. Modification was made to its lightness scale for improving the fit. In the metamerism experiment, 76 pairs of wool samples were prepared and assessed with 20 observations using a grey scale under 7 sources: D65, A, TL84, TL83, P27, W and WW. The experimental results were used to test 3 types of illuminant metamerism indices derived here. It was found that calculating colour difference using 3 colour difference formulae, i.e. CMC, BFD and CIE94 gave the most precise prediction to the visual results. The degree of precision is quite satisfactory in comparison with typical observer precision. A new standard deviate observer (SDO) was also derived. This together with the CIE SDO and 1964 Observer were tested using the author's and the Obande's data. The results showed that the new SDO predicted results more accurate than those from the other two CIE Observers. An Observer Metamerism Index (OMI) was also derived to indicate the degree of metamerism based upon the new SDO. The results showed that the new SDO was more suitable for indicating the degree of observer metamerism.
32

Analyse en ondelettes et prolongement des champs de potentiel : développement d'une théorie 3-D et application en géophysique /

Boukerbout, Hassina. January 2004 (has links)
Thesis (doctoral)--Université de Rennes, 2004. / Includes bibliographical references (p. [131]-[136]) . Also available on the World Wide Web.
33

Analysis of Optimized Design Tradeoffs in Application of Wavelet Algorithms to Video Compression

Wanis, Paul, Fairbanks, John S. 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / Because all video compression schemes introduce artifacts into the compressed video images, degradation occurs. These artifacts, generated by a wavelet-based compression scheme, will vary with the compression ratio and input imagery, but do show some consistent patterns across applications. There are a number of design trade-offs that can be made to mitigate the effect of these artifacts. By understanding the artifacts introduced by video compression and being able to anticipate the amount of image degradation, the video compression can be configured in a manner optimal to the application under consideration in telemetry.
34

A custom coprocessor for matrix algorithms

Amira, A. A. January 2001 (has links)
No description available.
35

Theory and realization of novel algorithms for random sampling in digital signal processing

Lo, King Chuen January 1996 (has links)
Random sampling is a technique which overcomes the alias problem in regular sampling. The randomization, however, destroys the symmetry property of the transform kernel of the discrete Fourier transform. Hence, when transforming a randomly sampled sequence to its frequency spectrum, the Fast Fourier transform cannot be applied and the computational complexity is N(^2). The objectives of this research project are (1) To devise sampling methods for random sampling such that computation may be reduced while the anti-alias property of random sampling is maintained : Two methods of inserting limited regularities into the randomized sampling grids are proposed. They are parallel additive random sampling and hybrid additive random sampling, both of which can save at least 75% of the multiplications required. The algorithms also lend themselves to the implementation by a multiprocessor system, which will further enhance the speed of the evaluation. (2) To study the auto-correlation sequence of a randomly sampled sequence as an alternative means to confirm its anti-alias property : The anti-alias property of the two proposed methods can be confirmed by using convolution in the frequency domain. However, the same conclusion is also reached by analysing in the spatial domain the auto-correlation of such sample sequences. A technique to evaluate the auto-correlation sequence of a randomly sampled sequence with a regular step size is proposed. The technique may also serve as an algorithm to convert a randomly sampled sequence to a regularly spaced sequence having a desired Nyquist frequency. (3) To provide a rapid spectral estimation using a coarse kernel : The approximate method proposed by Mason in 1980, which trades the accuracy for the speed of the computation, is introduced for making random sampling more attractive. (4) To suggest possible applications for random and pseudo-random sampling : To fully exploit its advantages, random sampling has been adopted in measurement Random sampling is a technique which overcomes the alias problem in regular sampling. The randomization, however, destroys the symmetry property of the transform kernel of the discrete Fourier transform. Hence, when transforming a randomly sampled sequence to its frequency spectrum, the Fast Fourier transform cannot be applied and the computational complexity is N"^. The objectives of this research project are (1) To devise sampling methods for random sampling such that computation may be reduced while the anti-alias property of random sampling is maintained : Two methods of inserting limited regularities into the randomized sampling grids are proposed. They are parallel additive random sampling and hybrid additive random sampling, both of which can save at least 75% , of the multiplications required. The algorithms also lend themselves to the implementation by a multiprocessor system, which will further enhance the speed of the evaluation. (2) To study the auto-correlation sequence of a randomly sampled sequence as an alternative means to confirm its anti-alias property : The anti-alias property of the two proposed methods can be confirmed by using convolution in the frequency domain. However, the same conclusion is also reached by analysing in the spatial domain the auto-correlation of such sample sequences. A technique to evaluate the auto-correlation sequence of a randomly sampled sequence with a regular step size is proposed. The technique may also serve as an algorithm to convert a randomly sampled sequence to a regularly spaced sequence having a desired Nyquist frequency. (3) To provide a rapid spectral estimation using a coarse kernel : The approximate method proposed by Mason in 1980, which trades the accuracy for the speed of the computation, is introduced for making random sampling more attractive. (4) To suggest possible applications for random and pseudo-random sampling : To fully exploit its advantages, random sampling has been adopted in measurement instruments where computing a spectrum is either minimal or not required. Such applications in instrumentation are easily found in the literature. In this thesis, two applications in digital signal processing are introduced. (5) To suggest an inverse transformation for random sampling so as to complete a two-way process and to broaden its scope of application. Apart from the above, a case study of realizing in a transputer network the prime factor algorithm with regular sampling is given in Chapter 2 and a rough estimation of the signal-to-noise ratio for a spectrum obtained from random sampling is found in Chapter 3. Although random sampling is alias-free, problems in computational complexity and noise prevent it from being adopted widely in engineering applications. In the conclusions, the criteria for adopting random sampling are put forward and the directions for its development are discussed.
36

Compact iris verification on portable computing platform.

January 2003 (has links)
Chun, Chun Nam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 73-75). / Abstracts in English and Chinese. / ABSTRACT --- p.i / 摘要 --- p.ii / ACKNOWLEDGEMENTS --- p.iii / TABLE OF CONTENTS --- p.iv / LIST OF FIGURES --- p.v / LIST OF TABLES --- p.vii / Chapter 1 --- INTRODUCTION --- p.01 / Chapter 1.1 --- Iris Texture as A Biometric Password --- p.01 / Chapter 1.1.1 --- Advantages --- p.02 / Chapter 1.1.2 --- Previous Work --- p.04 / Chapter 1.1.3 --- Operation Procedures --- p.06 / Chapter 1.1.3.1 --- Image Acquisition --- p.07 / Chapter 1.1.3.2 --- Iris Localization --- p.07 / Chapter 1.1.3.3 --- Image Encoding and Database Matching --- p.08 / Chapter 1.2 --- Motivation and Research Objective --- p.09 / Chapter 1.3 --- Thesis Outline --- p.11 / Chapter 2 --- IMAGE ACQUISITION --- p.13 / Chapter 2.1 --- Difficulties on Image Acquisition --- p.13 / Chapter 2.2 --- Our Iris Image Acquisition Setting --- p.13 / Chapter 3 --- PRE-PROCESSING --- p.15 / Chapter 3.1 --- Isolating the Region of Interest --- p.15 / Chapter 3.1.1 --- Conscious and Unconscious Recognition --- p.15 / Chapter 3.1.2 --- Iris Boundary Detection --- p.16 / Chapter 3.2 --- Iris-ring Unfolding and Normalization --- p.19 / Chapter 3.2.1 --- Eccentric-polar Coordinate System --- p.20 / Chapter 3.2.2 --- Iris-ring Unfolding --- p.22 / Chapter 3.2.3 --- Normalization --- p.22 / Chapter 3.3 --- Data Binarization --- p.24 / Chapter 4 --- RADON TRANSFORM BASED ENCODING AND MATCHING --- p.27 / Chapter 4.1 --- Radon Transform based Encoding --- p.28 / Chapter 4.2 --- Iris Code Matching --- p.32 / Chapter 4.2.1 --- Regional Correlation --- p.32 / Chapter 5 --- PALM-TOP IMPLEMENTATION ON COMPUTING PLATFORM --- p.36 / Chapter 5.1 --- Image Acquisition --- p.37 / Chapter 5.1.1 --- Desktop Version --- p.37 / Chapter 5.1.2 --- Palm-top Version --- p.37 / Chapter 5.2 --- Iris Localization --- p.39 / Chapter 5.2.1 --- Desktop Version --- p.39 / Chapter 5.2.2 --- Palm-top Version --- p.39 / Chapter 5.3 --- Image Encoding --- p.41 / Chapter 5.3.1 --- Desktop Version --- p.41 / Chapter 5.3.2 --- Palm-top Version --- p.41 / Chapter 5.4 --- Palm-Top Computer Application --- p.42 / Chapter 5.4.1 --- Palm-top Computer Setting --- p.42 / Chapter 5.4.2 --- Software Selection --- p.42 / Chapter 5.4.3 --- Technical Problems --- p.43 / Chapter 5.4.3.1 --- Problem 1: Memory Limitation --- p.43 / Chapter 5.4.3.2 --- Problem 2: Image Format --- p.44 / Chapter 5.4.3.3 --- Problem 3: Origin of Image --- p.44 / Chapter 5.5 --- Our Iris Recognition Platform --- p.44 / Chapter 6 --- EXPERIMENTAL RESULTS --- p.47 / Chapter 6.1 --- The Test Data --- p.47 / Chapter 6.2 --- Experiment One: Eccentric Polar Coordinates System Recognition Performance --- p.48 / Chapter 6.2.1 --- Performance Measure of Recognition --- p.48 / Chapter 6.2.2 --- Experimental Result --- p.49 / Chapter 6.3 --- Experiment Two: Radon Transform-based Recognition System Performance --- p.53 / Chapter 6.3.1 --- Intra-group Similarity vs. Inter-group Similarity --- p.54 / Chapter 6.3.2 --- Performance Comparison with an Existing System --- p.57 / Chapter 6.4 --- Experiment Three: The Resolution of Image in the Eccentric-polar Coordinates System --- p.58 / Chapter 7 --- CONCLUSION AND FUTURE WORK --- p.62 / Chapter 7.1 --- Conclusion --- p.62 / Chapter 7.2 --- Future Work --- p.63 / APPENDIX A --- p.66 / APPENDIX B --- p.67 / BIBLIOGRAPHY --- p.73
37

Complexity of Linear Summary Statistics

Pedrick, Micah G 01 January 2017 (has links)
Families of linear functionals on a vector space that are mapped to each other by a group of symmetries of the space have a significant amount of structure. This results in computational redundancies which can be used to make computing the entire family of functionals at once more efficient than applying each in turn. This thesis explores asymptotic complexity results for a few such families: contingency tables and unranked choice data. These are used to explore the framework of Radon transform diagrams, which promise to allow general theorems about linear summary statistics to be stated and proved.
38

Asymptotic Expansions of Berezin Transforms

Jonathan Arazy, Bent Orsted, jarazy@math.haifa.ac.il 31 July 2000 (has links)
No description available.
39

none

Lee, Tai-long 22 August 2006 (has links)
Abstract The broadcast industry is the non-profit organization, with disseminates the news, provides the entertainment, may change audience's manner and the behavior, widespread also is profound to society's influence, therefore, broadcasts the organization to have specially to emphasize the specialty, regarding each kind of specialized talented person's demand is earnest. How however has the series to gather broadcasts the organization complex specialized talented people, and obeys leader's command, unitedly aims at a common goal struggle, broadcasts the leader to have to be skilled in the leadership series imperial method and the skill. Moreover, because the broadcast frequency channel is open, each kind of broadcasting station sets up one after another, forms hundred school of thought contends the situation, the broadcast industry must survive in the competition management environment, and has the competitive advantage, the leader must grasp the current situation pulsation, effectively carries on the organization to transform. Broadcasts the leader to be supposed to relate from the crowd embarks, understanded the solution organization team characteristic, nimbly utilizes theleadership management the technology and the main point, can displaythe team strength, strengthens the staff achievements, achieves continues forever the development goal, then has the frontageinfluence to the national society. Although the broadcast industry is suitable the crowd relations which organizes to the enterprise, but broadcasts the training and the common business management which the leader receives alien, they also must consider the broadcast industry because the dissemination science and technology unceasingly progresses, brings each kind of impact and faces each challenge. Therefore, this research specially by the home well-known five broadcasting station's manager, the department manager and the basic unit staff, the altogether twenty artificial research objects, and with the depth document interview method, carries on time the transformation from the broadcast organization, discusses the leader special characteristic and the team interaction and the team and the member achievements connection and so on the subject, even influence which develops to the whole organization, hoped takes advantage of this describes the broadcast industry management and the management strategy and the blueprint, provides individual or the social reform, and is ambitious the investment broadcast enterprise development direction. But this research discovery, broadcasts the leader to be allowed because the person, because of events, to adopt the different condition leadership way as circumstances permit, but like can unfold the transformation leadership the special characteristic, regardless of to the team strength display also or the team and the staff achievements, all has reveals the influence effect. Essential character:¡GThe organization transforms, The leadership, The team, The achievements, Depth interview.
40

Gabor wavelets for human biometrics = Gaibo xiao bo zai ren ti shi bie zhong de ying yong /

Amin, Md. Ashraful. January 2009 (has links) (PDF)
Thesis (Ph.D.)--City University of Hong Kong, 2009. / "Submitted to the Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references.

Page generated in 0.0371 seconds