Recent years have witnessed increasing interest in using metaheuristics to solve the codebook generation problem (CGP) of vector quantization as well as increasing interest in reducing the computation time of metaheuristics. One of the recently proposed methods aimed at reducing the computation time of metaheuristics is based on the notion of pattern reduction (PR). The problem with PR is in that it may compress and remove patterns that are not supposed to be compressed and removed, thus decreasing the quality of the solution. In this thesis, we proposed a fuzzy version of PR called fuzzy pattern reduction (FPR) to reduce the possibility of compressing and removing patterns that are not supposed to be compressed and removed. To evaluate the performance of the proposed algorithm, we apply it to the following four metaheuristics: generalized Lloyd algorithm, code displacement, genetic k-means algorithm, and particle swarm optimization and use them to solve the CGP. Our experimental results show that the proposed algorithm can not only significantly reduce the computation time but also improve the quality of all the metaheuristics evaluated.

In this paper, we propose a novel approach of vector quantization using a merge-based hierarchical neural network. Vector quantization¡]VQ¡^is known as a very useful technique for lossy data compression. Recently, Neural network¡]NN¡^algorithms have been used for VQ. Vlajic and Card proposed a modified adaptive resonance theory (modified ART2¡^[1] which is a constructing tree structure clustering method. However, modified ART2 has disadvantages of slow construction rate and constructing many redundant levels. Therefore, we propose a more efficient approach for constructing the tree in this paper. Our method establishes only those required levels without losing the fidelity of a compressed image.

NPR (Non-Photo-Realistic Rendering) is a new and quick-developed research topic in Image Processing. The main purpose of NPR is to generate pencil sketching¡Bwatercolor and oil painting, something different from photos, automatically by computer algorithms. On the other hand, there is another technique called PR (Photo-Realistic Rendering). The goal of PR is to generate real objects by computer algorithms, such as Matting or Inpainting. Furthermore, NPR includes two modes¡Gone is with physical model, researchers could write programs to simulate NPR by the properties of physical model. Without physical model, researchers could write programs to simulate NPR by their observation and deliberation. This thesis to the latter, there is no physical model in NPR. In the viewpoint of artists, drawing is performance of light and shadow. Then, in scientific, drawing depends on the degree of luminance. Luminance supports artists block and direction when drawing. Moreover, This thesis is mainly simulating oil painting with impressionist.

In real-time, two way video communications, how to minimize the end-to-end delay for transmitting video data is very important. Since the delay produced by bits accumulated in the encoder buffer must be very small, we need an improved rate control to encode the video with high quality and maintain low buffer fullness. One approach to reduce the buffer fullness is to skip the encoding frames, but the frame-skipping will produce undesirable motion discontinuity in the encoded video sequence. In this thesis, we study the impact of low delay constraint in H.264 rate control and its improvements. The drawback of the H.264 rate control is it cannot handle the frame-skipping mechanism well. To modify this, we control the quantization parameter of each I-frame to avoid the buffer overflow and frame-skipping. Since encoding the I-frame by different quantization parameter will generate different rate and distortion for a group of pictures (GOP), we use Lagrangian optimization to find the tradeoff between rate and distortion for a GOP. By the estimation models of rate and distortion for a GOP, calculate the Lagrangian cost for each possible quantization parameter of I-frame, the quantization parameter with minimum Lagrangian cost will be our choice for I-frame. Simulation results show that our proposed rate control encode the video sequence with less skipped frames and with higher PSNR compared to H.264 rate control under low delay constraint.

The rapid-eye-movement (REM) sleep is one of the most important parts in overnight sleep. In this study, an automatic REM sleep staging rule is introduced. Compared with the traditional REM detection method, a distinct feature of this method is that it only requires two EOG signals and thus reduces the number of input signal channels significantly. We calculate the correlation coefficient series between two EOG signals. By representing such a series with a VQ coding method, several techniques are proposed to improve the classification rate. Experimental results are given to demonstrate the effectiveness of the proposed approach.

The purpose of this research is to investigate undergraduate students&rsquo / mental models about the quantization of physical observables. The research was guided by ethnography, case study, and content analysis integrated to each other. It focused on second-year physics and physics education students, who were taking the Modern Physics course at the Department of Physics, at Middle East Technical University. Wide range of data was collected by interview, observation, test, diary, and other documents during 2008-2 academic semester. The findings obtained from the qualitative analysis of the data indicated the following conclusions: (1) Students displayed six different mental models, defined as Scientific Model, Primitive Scientific Model, Shredding Model, Alternating Model, Integrative Model, and Evolution Model, about the quantization of physical observables. (2) Students&rsquo / models were influenced by the external sources such as textbooks (explanations in textbooks, bringing textbook into the classes, and the use of one or both textbooks), instructional elements (explanations in instruction, taking notes in classes, and studying before and after the classes+taking notes in classes+attending classes regularly), topic order, and classmate / they were influenced by the internal sources such as meta-cognitive elements, motivation, belief (the nature of science and the nature of quantum physics concepts), and familiarity and background about the concepts. (3) The models displayed by students developed with the contribution of these sources in different proportions. Furthermore, although upgrading in models was observed within the cases of quantization, students&rsquo / mental models about the quantization of physical observables are context dependent, and stable during the semester.

A Microsoft Windows program is designed to implement a Multi-Language Identification system based on formants estimation and vector quantization classifier with n-Gram and HMM. LPC is used here as an effective method for formants feature extraction of the speakers, and a new method for distance measure of VQ is also proposed.

Thesis (M.S.)--Brigham Young University. Dept. of Electrical and Computer Engineering, 2004. / Includes bibliographical references (p. 103-104).

In this dissertation, we devise a quantization scheme to construct eigenfunctions by classical periodic orbits in both regular systems as well as chaotic systems. Our method is based on the principle that eigenfunctions can be resolved from a time-dependent wavefunction. This is different from the classical (or EBK) quantization scheme that constructs eigenfunction in the energy-domain. The advantage of our method is that it can be applied to more varieties of systems, including some chaotic systems. Three systems, the simple harmonic oscillator, the x⁴-potential oscillator, and the x²y² quartic-oscillator, are used as examples for our eigenfunction construction. The key to the constructions is a family (or families) of periodic orbits with a newly defined quantization rule, the resolving quantization rule. The eigenspectrum for the x⁴-potential oscillator is also computed. Furthermore, the classical Green's function is used to explain the relation between the resolving quantization rule and the classical quantization rule. This dissertation begins with an introduction in Chapter 1. The semiclassical theory for the eigenfunction construction by periodic orbits is developed in Chapter 2. In Chapter 3 and Chapter 4, eigenfunctions are constructed for the simple harmonic oscillator, the x⁴-potential oscillator, and the x²y² quartic-oscillator. The eigenspectrum for the x⁴-potential oscillator is computed in Chapter 5. Chapter 6 is devoted to discussions including the interpretation of the resolving quantization rule from the classical Green's function, the interpretation of the photoabsorption spectrum for a Rydberg atom in a magnetic field, and the comparison of our method with the EBK quantization scheme. Conclusions are made in Chapter 7. / text

A new ensemble method for cluster analysis is introduced, which can be interpreted in two different ways: As complexity-reducing preprocessing stage for hierarchical clustering and as combination procedure for several partitioning results. The basic idea is to locate and combine structurally stable cluster centers and/or prototypes. Random effects of the training set are reduced by repeatedly training on resampled sets (bootstrap samples). We discuss the algorithm both from a more theoretical and an applied point of view and demonstrate it on several data sets. (author's abstract) / Series: Working Papers SFB "Adaptive Information Systems and Modelling in Economics and Management Science"