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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.
51

GA-based Fractal Image Compression and Active Contour Model

Wu, Ming-Sheng 01 January 2007 (has links)
In this dissertation, several GA-based approaches for fractal image compression and active contour model are proposed. The main drawback of the classical fractal image compression is the long encoding time. Two methods are proposed in this dissertation to solve this problem. First, a schema genetic algorithm (SGA), in which the Schema Theorem is embedded in GA, is proposed to reduce the encoding time. In SGA, the genetic operators are adapted according to the Schema Theorem in the evolutionary process performed on the range blocks. We find that such a method can indeed speedup the encoder and also preserve the image quality. Moreover, based on the self-similarity characteristic of the natural image, a spatial correlation genetic algorithm (SC-GA) is proposed to further reduce the encoding time. There are two stages in the SC-GA method. The first stage makes use of spatial correlations in images for both the domain pool and the range pool to exploit local optima. The second stage is operated on the whole image to explore more adequate similarities if the local optima are not satisfactory. Thus not only the encoding speed is accelerated further, but also the higher compression ratio is achieved, because the search space is limited relative to the positions of the previously matched blocks, fewer bits are required to record the offset of the domain block instead of the absolute position. The experimental results of comparing the two methods with the full search, traditional GA, and other GA search methods are provided to demonstrate that they can indeed reduce the encoding time substantially. The main drawback of the traditional active contour model (ACM) for extracting the contour of a given object is that the snake cannot converge to the concave region of the object under consideration. An improved ACM algorithm is proposed in this dissertation to solve this problem. The algorithm is composed of two stages. In the first stage, the ACM with traditional energy function guides the snake to converge to the object boundary except the concave regions. In the second stage, for the control points which stay outside the concave regions, a proper energy template are chosen and are added in the external energy. The modified energy function is applied so as to move the snake toward the concave regions. Therefore, the object of interest can be completely extracted. The experimental results show that, by using this method, the snake can indeed completely extract the boundary of the given object, while the extra cost is very low. In addition, for the problem that the snake cannot precisely extract the object contour when the number of the control points on the snake is not enough, a GA-based ACM algorithm is presented to deal with such a problem. First the improved ACM algorithm is used to guide the snake to approximately extract the object boundary. By utilizing the evolutionary strategy of GA, we attempt to extract precisely the object boundary by adding a few control points into the snake. Similarly, some experimental results are provided to show the performance of the method.
52

Improving the Treated Water for Water Quality and Good Tastes from Traditional and Advanced Water Treatment Plants

HAn, Chia-Yun 19 July 2007 (has links)
The purpose of this research is to compare the performance for the water quality of two traditional water treatment plants (WTP) and three advanced water treatment plants (AWTP), and to investigate the treated drinking water in distribution systems in Kaohsiung area for promoting the consumers¡¦ self-confidence. Samples of the treated water from five major water supplies¡¦ WTP(noted numbers: WF1, WF2, WF3, WF4 and WF5) and the tap water at user¡¦s end were selected in planning of this work. It was the traditional WTP stage with treated drinking water and distribution systems in Kaohsiung area During 91 year to 92 year, so we conducted WF1 and WF2 of 8 times sampling and WF3, WF4 and WF5 for 2 times sampling at this stage. In and after 93 year, we conducted WF1, WF2, WF3, WF4 and WF5 of 8 times sampling from 93 year to 94year for the advanced WTP stage. The major tests related with the parameters of influencing operation condition included pH, odor (abbreviated as TON), total trihalomethane (abbreviated as THMs), haloacetic acids (abbreviated as HAAs), nitrogen (abbreviated as, NH3-N, hardness, total dissolved solid (abbreviated as TDS), alkalinity, total organic carbon (abbreviated as TOC), calcium ion, flavor profile analysis (abbreviated as FPA), and suspension observation in boiling with treated waters from two WTP , three AWTP and the tap water at user¡¦s end in a distribution system. It point out the better quality of treated water used the advanced water treatment plants than that of traditional water treatment plant. The items with improvement of water quality, including THMs, HAAs, hardness, TON, 2-MIB, TOC, alkinality and Ca ions concentration, is presented. Their efficiency for improvement are respectively 47%, 29%, 43%, 11%, 29%, 15%, 14% and 34%. The insignificant efficiency were concentrated at TDS, NH3-N, pH and FPA. Water quality of six items are fitted for the drinking water standard at present in Taiwan (such as: odor<3 TON; THMs<0.1 mg/L; NH3-N<0.1 mg/L; TDS< 600 mg/L; Hardness <400 mg as CaCO3/L; 6.0<pH <8.5). The HAAs is fit for water quality USEPA first stage water standard (HAAs<80 £gg/L). In the suspension observation in boiling experimentation, we cooperate with the experiment of suspension observation in boiling to do contrast with TDS and hardness experiment, which can find out, the treated water after the advanced procedure, the time with boiling increases, the condition of its suspended substance has great reduction. It show treated drinking water after the advanced WTP can huge improve the traditional WTP¡¦s white suspended substance or white material precipitate questions in the boiling. In the contour map for water quality , we found that Gushan District, Lingya District, Qianzhen District, Xiaogang District, Fongshan City and Daliao Shiang etc had higher concentration profile in the four season (included spring, summer, fall and winter ) and during two seasons (included raining and drying) in the water supplies systems. We hope the contour map can offer a clear information of conveyer system administrator of drinking water and let administrator know where areas have high concentration produced in water quality management planning, in order to having priority or effective solutions (included washing the pipeline, changing the pipeline, changing the water flow, etc.).
53

Using Subpixel Technology in Contour Recognition on Low-resolution Hexagonal Images

Lee, Yorker 08 June 2000 (has links)
Pattern recognition is very important in automatic industry. The automation machinery vision system must exchange information very fast with the object we need. So the machinery vision system must have powerful recognition ability. There are more important on image processing, lately. But most researches of image processing are developed on high-resolution image. However, in same situation, for increasing the processing speed, reducing the saving space. Low-resolution image are the only way to achieve the above condition up to now. For the purpose of quickly recognition, we construct the recognition system on low-resolution image. From observing the characteristic of hexagonal grid, we knew the hexagonal grid have greater angular resolution and better image performance than rectangular grid. Therefore, we apply the hexagonal grid on low-resolution image, and using Curve Bend Function (call CBF) on hexagonal gird system; for promoting the accuracy of recognition.We presented an technique of subpixel on low-resolution hexagonal image to obtain better results.
54

PSO-based Fractal Image Compression and Active Contour Model

Tseng, Chun-chieh 23 July 2008 (has links)
In this dissertation, particle swarm optimization (PSO) is utilized for fractal image compression (FIC) and active contour model (ACM). The dissertation is divided into two parts. The first part is concerned with the FIC and the second part with ACM. FIC is promising both theoretically and practically for image compression. However, since the encoding speed of the traditional full search method is very time-consuming, FIC with full search is unsuitable for real-time applications. In this dissertation, several novel PSO-based approaches incorporating the edge property of the image blocks are proposed to speedup the encoder and preserve the image quality. Instead of the full search, a direction map is built according to the edge type of the image blocks, which directs the particles in the swarm to regions consisting of candidates of higher similarity. Therefore, the searching space is reduced and the speedup can be achieved. Also, since the strategy is performed according to the edge property, better visual effect can be preserved. Experimental results show that the visual-based particle swarm optimization speeds up the encoder 125 times faster with only 0.89 dB decay of image quality in comparison to the full search method. The second part of the dissertation is concerned with the active contour model for automatic object boundary identification. In the traditional methods for ACM, each control point searches its new position in a small nearby window. Consequently, the boundary concavities cannot be searched accurately. Some improvements have been made in the past to enlarge the searching space, yet they are still time-consuming. To overcome these drawbacks, a novel multi-population PSO technique is adopted in this dissertation to enhance the concavity searching capability and reduce the search time but in a larger searching window. In the proposed scheme, to each control point in the contour there is a corresponding swarm of particles with the best swarm particle as the new control point. The proposed optimizer not only inherits the spirit of the original PSO in each swarm but also shares information of the surrounding swarms. Experimental results demonstrate that the proposed method can improve the search of object concavities without extra computation time.
55

Decoupled Deformable Model For 2D/3D Boundary Identification

Mishra, Akshaya Kumar 07 1900 (has links)
The accurate detection of static object boundaries such as contours or surfaces and dynamic tunnels of moving objects via deformable models is an ongoing research topic in computer vision. Most deformable models attempt to converge towards a desired solution by minimizing the sum of internal (prior) and external (measurement) energy terms. Such an approach is elegant, but frequently mis-converges in the presence of noise or complex boundaries and typically requires careful semi-dependent parameter tuning and initialization. Furthermore, current deformable model based approaches are computationally demanding which precludes real-time use. To address these limitations, a decoupled deformable model (DDM) is developed which optimizes the two energy terms separately. Essentially, the DDM consists of a measurement update step, employing a Hidden Markov Model (HMM) and Maximum Likelihood (ML) estimator, followed by a separate prior step, which modifies the updated deformable model based on the relative strengths of the measurement uncertainty and the non-stationary prior. The non-stationary prior is generated by using a curvature guided importance sampling method to capture high curvature regions. By separating the measurement and prior steps, the algorithm is less likely to mis-converge; furthermore, the use of a non-iterative ML estimator allows the method to converge more rapidly than energy-based iterative solvers. The full functionality of the DDM is developed in three phases. First, a DDM in 2D called the decoupled active contour (DAC) is developed to accurately identify the boundary of a 2D object in the presence of noise and background clutter. To carry out this task, the DAC employs the Viterbi algorithm as a truncated ML estimator, curvature guided importance sampling as a non-stationary prior generator, and a linear Bayesian estimator to fuse the non-stationary prior with the measurements. Experimental results clearly demonstrate that the DAC is robust to noise, can capture regions of very high curvature, and exhibits limited dependence on contour initialization or parameter settings. Compared to three other published methods and across many images, the DAC is found to be faster and to offer consistently accurate boundary identification. Second, a fast decoupled active contour (FDAC) is proposed to accelerate the convergence rate and the scalability of the DAC without sacrificing the accuracy by employing computationally efficient and scalable techniques to solve the three primary steps of DAC. The computational advantage of the FDAC is demonstrated both experimentally and analytically compared to three computationally efficient methods using illustrative examples. Finally, an extension of the FDAC from 2D to 3D called a decoupled active surface (DAS) is developed to precisely identify the surface of a volumetric 3D image and the tunnel of a moving 2D object. To achieve the objectives of the DAS, the concepts of the FDAC are extended to 3D by using a specialized 3D deformable model representation scheme and a computationally and storage efficient estimation scheme. The performance of the DAS is demonstrated using several natural and synthetic volumetric images and a sequence of moving objects.
56

Logaritminės eilės begalinio indekso nehomogeninis kraštinis Rymano uždavinys sričiai, apribotai begaliniu Dini – Lipšico kontūru / The inhomogeneous Riemann boundary - value problem with infinite index of the logarithmic order for the region limited by the infinity Dini - Lipschitz contour

Spetylaitė, Jurga 27 August 2009 (has links)
Šiame darbe formuluojamas ir nagrinėjamas logaritminės eilės α≥1 kraštinis Rymano uždavinys sričiai, apribotai begaliniu Dini – Lipšico kontūru. Darbe naudojamasi Koši tipo integralo su logaritminiu tankiu asimptotika. Iš esmės skiriasi funkcijos Фα(z) ir Фα*(z). Pirmajame integrale lnαt yra analizinės funkcijos lnαz kontūrinė reikšmė ir Koši tipo integralui Фα(z) yra gauta daugianarė asimptotinė formulė. Su kanonine funkcija X(z) siejamai funkcijai Фα*(z) gautoje asimptotinėje formulėje yra tik vienas, greičiausiai augantis narys, kai z→∞. Šios informacijos apie Фα*(z) kitimą nepakanka, nagrinėjant nehomogeninį uždavinį. Todėl buvo būtina panaudoti Dini – Lipšico kontūrą. Tik pareikalavus, kad L΄ būtų eilės q>α Dini – Lipšico kontūras, įrodyta, kad funkcija ηα(t) yra tolydi ir aprėžta kontūro L΄ taškuose, o sveikosios funkcijos F0(z) nuliai išdėstyti ant realiosios ašies neigiamos pusašės. Esant tokiam kontūrui, pavyko įrodyti, jog atskirasis nehomogeninio uždavinio sprendinys yra aprėžtas. Gautas suformuluoto uždavinio bendrasis sprendinys aprėžtų funkcijų klasėje BL. / In this work is formulated and studied boundary Riemann problem of logarithmic order α≥1 for the space bounded by the infinite Dini – Lipschitz contour. In this paper is used asymptotics of Cauchy type integrals with a logarithmic density. Basically differ functions Фα(z) and Фα*(z). In the first integral lnαt is contour value of the analytical function lnαz and for Cauchy-type integral Фα(z) is obtained polynomial asymptotic formula. Function Фα*(z) associated with the canonical function X(z) obtained in asymptotic formula is the only one, the fastest growing member, when z→∞. The information about the change of the Фα*(z) is insufficient considering inhomogeneous problem. It is necessary to use the Dini – Lipschitz contour. Let L΄ be Dini – Lipschitz contour of q>α order, it is proved that the function ηα(t) is continuous and bounded in contour L΄ points, and zeros of entire function F0(z) are arranged on the negative semi-axis of the real axis. Being the before mentioned contour, it was proved that a separate inhomogeneous target solution is bounded. In this work is obtained the general solution of formulated task of bounded functions in class BL.
57

The evolution of snake toward automation for multiple blob-object segmentation

Saha, Baidya Nath Unknown Date
No description available.
58

Fast Contour Matching Using Approximate Earth Mover's Distance

Grauman, Kristen, Darrell, Trevor 05 December 2003 (has links)
Weighted graph matching is a good way to align a pair of shapesrepresented by a set of descriptive local features; the set ofcorrespondences produced by the minimum cost of matching features fromone shape to the features of the other often reveals how similar thetwo shapes are. However, due to the complexity of computing the exactminimum cost matching, previous algorithms could only run efficientlywhen using a limited number of features per shape, and could not scaleto perform retrievals from large databases. We present a contourmatching algorithm that quickly computes the minimum weight matchingbetween sets of descriptive local features using a recently introducedlow-distortion embedding of the Earth Mover's Distance (EMD) into anormed space. Given a novel embedded contour, the nearest neighborsin a database of embedded contours are retrieved in sublinear time viaapproximate nearest neighbors search. We demonstrate our shapematching method on databases of 10,000 images of human figures and60,000 images of handwritten digits.
59

Modelagem numérica do terreno na avaliação do volume admissível em canais de cordões de contorno nivelados

Gomes, Luciano Nardini [UNESP] 16 December 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-16Bitstream added on 2014-06-13T21:04:34Z : No. of bitstreams: 1 gomes_ln_dr_botfca.pdf: 919435 bytes, checksum: 21a680807df6222aa5f0029cc1b06f57 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A ação de processos erosivos em áreas rurais constitui um dos principais problemas da agricultura mundial. A falta de ações conservacionistas nessas áreas, somadas às ações de intemperismo proporciona perda considerável de solos agricultáveis, prejuízo ambiental que é acrescido pela poluição e assoreamento dos rios. Na tentativa de potencializar a produção de alimentos e visando atender à demanda proporcionada pelo crescente aumento da população, técnicas como o cultivo mínimo e o plantio direto contribuem para que haja equilíbrio entre produção agrícola e o meio ambiente, interesse patente das gerações presente e futura. Contudo, notadamente em pequenas propriedades rurais, é comum ainda o uso de tecnologias convencionais, como implantação de cordões de contorno. Em pequena propriedade rural, em área de reforma de pastagem, foram locados quatro cordões de contorno utilizando trator e arado convencional. Com estação total foram realizados dois levantamentos planialtimétricos, logo após a construção dos cordões de contorno e decorridos doze meses. Os dados foram processados pelos softwares DataGEOSIS e LandDESKTOP, onde foram criados artifícios para o cálculo do volume admissível nos canais dos cordões de contorno nas duas épocas distintas com o objetivo de verificar a validade da modelagem numérica do terreno na caracterização da movimentação de solo nos canais. Com base na metodologia adotada foi possível concluir que o modelo numérico do terreno permitiu avaliar o volume de solo movimentado nas três feições de relevo estudadas (relevo natural à montante, fundo do canal e camalhão), quando se constatou que a diminuição da capacidade de acúmulo de águas pluviais nos cordões de contorno foi em média 20,76% em um ano. / The actions of the erosive process in rural areas constitutes one of the most serious problem in agriculture worldwide. The lack of conservationist actions in those areas added to the weathering actions led to a preoccupying agricultural soil loss, environmental damage increased by pollution and rivers sedimentation. To attempt to increase the food production and aiming to help the food demand due to the population increasing, techniques like minimum tillage and no tillage contribute to the equilibrium between agricultural production and environment, what is the interest of the current and future generations. However, mainly in small farms it is common the use of conventional techniques like the contour lines implantation. In an area of pasture reformation into a small farm, four contour lines were demarcated using a tractor and conventional plow. Using a total station were made two topographic survey just after the contour lines demarcation and after twelve months. The data were processed using the software DataGEOSIS and LandDESKTOP, where artifices were created to the calculation of the possible water volume into channels of contour lines for the two dates of surveying, aiming to verify the validity of numerical terrain model to the soil movement characterization into channels. Considering the methodology used was possible to conclude that the numerical terrain model allowed to evaluate the soil volume alteration in the three relief forms studied (natural relief above, channel bottom and soil ridge), when was verified that the water storage capacity into contour lines decreased in average 20,76 % in a year.
60

Modelagem numérica do terreno na avaliação do volume admissível em canais de cordões de contorno nivelados /

Gomes, Luciano Nardini, 1979- January 2009 (has links)
Resumo: A ação de processos erosivos em áreas rurais constitui um dos principais problemas da agricultura mundial. A falta de ações conservacionistas nessas áreas, somadas às ações de intemperismo proporciona perda considerável de solos agricultáveis, prejuízo ambiental que é acrescido pela poluição e assoreamento dos rios. Na tentativa de potencializar a produção de alimentos e visando atender à demanda proporcionada pelo crescente aumento da população, técnicas como o cultivo mínimo e o plantio direto contribuem para que haja equilíbrio entre produção agrícola e o meio ambiente, interesse patente das gerações presente e futura. Contudo, notadamente em pequenas propriedades rurais, é comum ainda o uso de tecnologias convencionais, como implantação de cordões de contorno. Em pequena propriedade rural, em área de reforma de pastagem, foram locados quatro cordões de contorno utilizando trator e arado convencional. Com estação total foram realizados dois levantamentos planialtimétricos, logo após a construção dos cordões de contorno e decorridos doze meses. Os dados foram processados pelos softwares DataGEOSIS e LandDESKTOP, onde foram criados artifícios para o cálculo do volume admissível nos canais dos cordões de contorno nas duas épocas distintas com o objetivo de verificar a validade da modelagem numérica do terreno na caracterização da movimentação de solo nos canais. Com base na metodologia adotada foi possível concluir que o modelo numérico do terreno permitiu avaliar o volume de solo movimentado nas três feições de relevo estudadas (relevo natural à montante, fundo do canal e camalhão), quando se constatou que a diminuição da capacidade de acúmulo de águas pluviais nos cordões de contorno foi em média 20,76% em um ano. / Abstract : The actions of the erosive process in rural areas constitutes one of the most serious problem in agriculture worldwide. The lack of conservationist actions in those areas added to the weathering actions led to a preoccupying agricultural soil loss, environmental damage increased by pollution and rivers sedimentation. To attempt to increase the food production and aiming to help the food demand due to the population increasing, techniques like minimum tillage and no tillage contribute to the equilibrium between agricultural production and environment, what is the interest of the current and future generations. However, mainly in small farms it is common the use of conventional techniques like the contour lines implantation. In an area of pasture reformation into a small farm, four contour lines were demarcated using a tractor and conventional plow. Using a total station were made two topographic survey just after the contour lines demarcation and after twelve months. The data were processed using the software DataGEOSIS and LandDESKTOP, where artifices were created to the calculation of the possible water volume into channels of contour lines for the two dates of surveying, aiming to verify the validity of numerical terrain model to the soil movement characterization into channels. Considering the methodology used was possible to conclude that the numerical terrain model allowed to evaluate the soil volume alteration in the three relief forms studied (natural relief above, channel bottom and soil ridge), when was verified that the water storage capacity into contour lines decreased in average 20,76 % in a year. / Orientador: Lincoln Gehring Cardoso / Coorientador: João Carlos da Costa Catalão Fernandes / Banca: Zacarias Xavier de Barros / Banca: Vilmar Antonio Rodrigues / Banca: Sérgio Pascola de Campos / Banca: Fernanda Leite Ribeiro / Doutor

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