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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.
41

Weapon Detection In Surveillance Camera Images

Vajhala, Rohith, Maddineni, Rohith, Yeruva, Preethi Raj January 2016 (has links)
Now a days, Closed Circuit Television (CCTV) cameras are installedeverywhere in public places to monitor illegal activities like armedrobberies. Mostly CCTV footages are used as post evidence after theoccurrence of crime. In many cases a person might be monitoringthe scene from CCTV but the attention can easily drift on prolongedobservation. Eciency of CCTV surveillance can be improved by in-corporation of image processing and object detection algorithms intomonitoring process.The object detection algorithms, previously implemented in CCTVvideo analysis detect pedestrians, animals and vehicles. These algo-rithms can be extended further to detect a person holding weaponslike rearms or sharp objects like knives in public or restricted places.In this work the detection of weapon from CCTV frame is acquiredby using Histogram of Oriented Gradients (HOG) as feature vector andarticial neural networks performing back-propagation algorithm forclassication.As a weapon in the hands of a human is considered to be greaterthreat as compared to a weapon alone, in this work the detection ofhuman in an image prior to a weapon detection has been found advan-tageous. Weapon detection has been performed using three methods.In the rst method, the weapon in the image is detected directly with-out human detection. Second and third methods use HOG and back-ground subtraction methods for detection of human prior to detectionof a weapon. A knife and a gun are considered as weapons of inter-est in this work. The performance of the proposed detection methodswas analysed on test image dataset containing knives, guns and im-ages without weapon. The accuracy rate 84:6% has been achievedby a single-class classier for knife detection. A gun and a knife havebeen detected by the three-class classier with an accuracy rate 83:0%.
42

Implementation of Directional Median Filtering using Field Programmable Gate Arrays

Gundam, Madhuri 17 December 2010 (has links)
Median filtering is a non-linear filtering technique which is effective in removing impulsive noise from data. In this thesis, directional median filtering has been implemented using cumulative histogram of samples in several directions. Different methods to implement directional median filtering have been proposed. The filtered images are smoothed along the direction of the filtering window. All implementations aimed to generate outputs in the least amount of time, while reducing the resource utilization on hardware. The implementation methods were designed for Xilinx Virtex 5 FPGA devices but were also attempted on Spartan 3E. The proposed methods used less than 30% of the resources on Virtex 5 FPGA but the resource utilization on Spartan 3E exceeded the number of available resources. After an initial delay, methods 1 and 2 generate a new output for every 5 clock cycles while method 3 generates an output for every 1.5 clock cycles.
43

Quality and real-time performance assessment of color-correction methods : A comparison between histogram-based prefiltering and global color transfer

Nilsson, Linus January 2018 (has links)
In the field of computer vision and more specifically multi-camera systems color correction is an important topic of discussion. The need for color-tone similarity among multiple images that are used to construct a single scene is self-evident. The strength and weaknesses of color- correction methods can be assessed by using metrics to measure structural and color-tone similarity and timing the methods. Color transfer has a better structural similarity than histogram-based prefiltering and a worse color-tone similarity. The color transfer method is faster than the histogram-based prefiltering. Color transfer is a better method if the focus is a structural similar image after correction, if better color-tone similarity at the cost of structural similarity is acceptable histogram-based prefiltering is a better choice. Color transfer is a faster method and is easier to run with a parallel computing approach then histogram-based prefiltering. Color transfer might therefore be a better pick for real-time applications. There is however more room to optimize an implementation of histogram-based prefiltering utilizing parallel computing.
44

Modelo multi-estados markoviano não homogêneo com efeitos dinâmicos / Non-homogeneous Markov models with dynamic effects.

Arashiro, Iracema Hiroko Iramina 08 May 2008 (has links)
Modelos multi-estados têm sido utilizados para descrever o comportamento de unidades amostrais cuja principal resposta é o tempo necessário para a ocorrência de seqüências de eventos. Consideramos um modelo multi-estados markoviano, não homogêneo, que incorpora covariáveis cujos efeitos podem variar ao longo do tempo (efeitos dinâmicos), o que permite a generalização dos modelos usualmente empregados. Resultados assintóticos mostram que procedimentos de estimação baseados no método histograma crivo convergem para um processo gaussiano. A metodologia proposta mostra-se adequada na modelagem de dados reais para comparação de desenvolvimento de recém-nascidos pré-termo com os a termo. Estudos com dados gerados artificialmente confirmam os resultados teóricos obtidos. / Multi-state models have been used to describe the behavior of sample units where the principal response is the time needed for the occurrence of a sequence of events. We consider a non-homogeneous Markovian multi-state model that incorporates covariates with time-dependent coefficient (dynamic effects), generalizing models usually employed. The asymptotic results show that the estimators based on the method of histogram sieves converge to a Gaussian process. The proposed methodology revels adequated for modeling data related to the comparison of developement of preterm infants with term infants. The studies with artificially generated data confirm the asymptotic results.
45

Fundamental Study For Supplier Quality Improvement at AP&T Presses AB Sweden

Yah, Fritz Alum, Che, Jian January 2008 (has links)
This thesis aims at securing the quality of components from AP&T’s suppliers and to get a picture of different suppliers’ processes. In this thesis, samples supplied by various AP&T suppliers where measured at AP&T to gather data on how well the parts met design specifications. The collected data were analyzed using histogram and stratification. Further analysis was done using pareto chart and capability indices. Only the critical dimensions identified from the pareto chart together with discussions with experts on the shop floor were further analyzed using capability indices. This was done to focus more on the critical dimensions which needed more attention. The findings were critically studied and suggestions were made which served as a fundamental base for supplier product quality improvement plan at AP&T. However, there was no direct contact with the supplier process to ascertain its being in control; therefore, product characterization was carried out. In this case, all the results obtained from the analyses only gave a momentary picture of the process. Therefore, the results can not be used for future predictions.In the analysis, special attention was laid on the shape, spread and centering of the histogram. Studies were also done on the significant few; got from the pareto chart. Use was made of capability indices to get the momentary fall-outs of ppm and the percentage of the specification band used up by the process. / Uppsatsnivå: D
46

Modelo multi-estados markoviano não homogêneo com efeitos dinâmicos / Non-homogeneous Markov models with dynamic effects.

Iracema Hiroko Iramina Arashiro 08 May 2008 (has links)
Modelos multi-estados têm sido utilizados para descrever o comportamento de unidades amostrais cuja principal resposta é o tempo necessário para a ocorrência de seqüências de eventos. Consideramos um modelo multi-estados markoviano, não homogêneo, que incorpora covariáveis cujos efeitos podem variar ao longo do tempo (efeitos dinâmicos), o que permite a generalização dos modelos usualmente empregados. Resultados assintóticos mostram que procedimentos de estimação baseados no método histograma crivo convergem para um processo gaussiano. A metodologia proposta mostra-se adequada na modelagem de dados reais para comparação de desenvolvimento de recém-nascidos pré-termo com os a termo. Estudos com dados gerados artificialmente confirmam os resultados teóricos obtidos. / Multi-state models have been used to describe the behavior of sample units where the principal response is the time needed for the occurrence of a sequence of events. We consider a non-homogeneous Markovian multi-state model that incorporates covariates with time-dependent coefficient (dynamic effects), generalizing models usually employed. The asymptotic results show that the estimators based on the method of histogram sieves converge to a Gaussian process. The proposed methodology revels adequated for modeling data related to the comparison of developement of preterm infants with term infants. The studies with artificially generated data confirm the asymptotic results.
47

Mapeamento das áreas de inundação utilizando imagens C–SAR e SRTM , nas províncias de Santa Fé e Entre Ríos, Argentina.

Graosque, Jones Zamboni January 2018 (has links)
Eventos de inundação são fenômenos geralmente associados a eventos de chuvas intensas. Nesses eventos a cobertura de nuvens, normalmente, prejudica o mapeamento com uso de imagens ópticas. Assim, este trabalho tem como objetivo avaliar os resultados de mapeamento de áreas de inundação utilizando imagens SAR e SRTM. Para aplicação dos métodos foram analisadas as áreas de inundação nas cidades de Santa Fe e Parana, na Argentina. Embora a maior inundação registrada tenha sido no ano de 2003, registros de inundação são frequentemente observados nas províncias de Santa Fé e Entre Ríos. Foi utilizado imagens do satélite Sentinel-1, equipado com sensor C-SAR com dupla polarização (VV/VH). As imagens obtidas são do tipo Interferométrico (IW) Ground Range Detected (GRDH) com resolução espacial de 10 m. Foram utilizadas imagens em períodos com e sem eventos de inundação entre 2016 e 2017, calibradas e coregistradas. Sobre as imagens foram aplicadas técnicas de limiarização e de análise temporal para mapear a mancha de inundação. Também foi elaborado mapa a partir do Modelo Digital de Elevação (MDE) utilizando como referência estações de medição de nível da água dos rios. A validação de todos os métodos foi totalmente remota, baseando-se em um mapeamento da inundação de abril de 2003 na cidade de Santa Fe. Além disso, imagens publicadas de eventos de inundação complementaram a validação e foi possível comparar os resultados com uma imagem óptica Landsat – 8 com resolução de 15 m do dia 22 de fevereiro de 2016, quando o nível do rio Paraná estava acima do nível de alerta Os resultados dos três mapeamentos foram somados para formar uma única imagem com a mancha de inundação em comum. Entre as melhores acurácias, o método de análise do MDE atingiu o melhor resultado, 82% da área de inundação, no entanto, considerando os três métodos, a acurácia atinge mais de 91% de precisão. A técnica de limiarização foi mais eficiente em áreas sem alvos verticais, como áreas urbanas por exemplo. O MDE foi eficiente para simular a inundação em todos os alvos, no entanto em modelos de elevação com melhor resolução, o resultado final do mapeamento será mais preciso. A análise temporal mostrou ser uma técnica promissora para mapeamentos de inundação, no entanto um mapa detalhado de uso de solo é fundamental para aprimorar o resultado desta análise. Todos os processos foram feitos remotamente, possibilitando o desenvolvimento no futuro de um sistema automático para detecção de evento de inundação que pode ser aplicado em áreas com características similares. / Flood events usually go hand in hand with intensive rainfall during which clouds compromise any mapping attempts with optical imagery. Thus, this thesis aims at evaluate the results of mapping flood areas using SAR and SRTM images. For this purpose, flood areas in the cities Santa Fe and Parana in Argentina were analyzed. While the worst flood was registered in 2003, flood events frequently occur in both provinces Santa Fé and Entre Ríos. The employed Sentinel-1 satellite carrying a C-SAR sensor with dual polarization (VV/VH) provided interferometric (IW) Ground Range Detected (GRDH) imagery with a spatial resolution of 10 meters. Images from periods with and without flood events between 2016 and 2017 were calibrated and co-registered. Subsequently on the images were applied threshold and time analysis techniques, as well as a Digital Elevation Model (DEM) analysis with data from stations which measure the rivers’ water levels. The validation of all methods was totally remote, based on a flood mapping of April 2003 in the city of Santa Fe. In addition, published images of flood events complemented the validation and it was possible to compare the results with an optical image Landsat - 8 with 15 m resolution of February 22, 2016, when the level of the Paraná River was above the alert level The three maps were summed to form a single image with the flood spot in common. Among the best accuracy, the MDE analysis method achieved the best result, 82% of the flood area, however, considering all three methods, the accuracy reaches more than 91% accuracy. The thresholding technique was more efficient in areas with no vertical targets, such as urban areas. The DEM was efficient to simulate flooding on all targets, however using elevation models with better resolution, the final result of the mapping will be more accurate. The temporal analysis showed to be a promising technique for flood mapping, however a detailed map of land use is fundamental to improve the results of this analysis. All processes were done remotely, allowing the future development of an automatic flood event detection system that can be applied in areas with similar characteristics.
48

Automatisk bedömning av reglerkretsarsprestanda / Automatic Evaluation of Control Loop Performance

Holmqvist, Peter January 2005 (has links)
<p>In this thesis, a computer program that in a simple way can calculate the performance of control loops at the refinery Preemraff Lysekil has been created. The computer program has been adapted to the environment at Preemraff Lysekil. Theories for evaluation has been studied in aspect of reliability and of automatic implementation. The evaluation has been carried out from data collected directly from control loops at the refinery and from simulated control loops with implemented errors. </p><p>Among the studied methods are Harris index and Stattin´s oscillation index. According to the literature the Harris index is the most used for measure of control performance, but the results show that it does not work as a single measure at Preemraff Lysekil. However Stattin´s oscillation index works well and can be used for detection of oscillations. Statistic measures like variance, IAE, ISE and a method based on histogram are also studied. All the statistical measures are simple to implement and are rather accurate. Several tests on control loops has been carried out and it has been shown that it ís enough to use the method based on histograms and Stattins oscillation index to get a good picture of the performace of the control loops at Preemraff Lysekil. </p><p>The work has resulted in a MATLAB tool that evaluates the control loops and can be run at any time. The tool first calculates Stattin´s oscillation index. The loops that are oscillating are marked. In the next step, the method based on histograms is used and a list with the worst performing loops at the top is created.</p>
49

Automatic Exposure Correction And Local Contrast Setting For Diagnostic Viewing of Medical X-ray Images

Pehrson Skidén, Ottar January 2010 (has links)
<p>To properly display digital X-ray images for visual diagnosis, a proper display range needs to be identified. This can be difficult when the image contains collimators or large background areas which can dominate the histograms. Also, when there are both underexposed and overexposed areas in the image it is difficult to display these properly at the same time. The purpose of this thesis is to find a way to solve these problems. A few different approaches are evaluated to find their strengths and weaknesses. Based on Local Histogram Equalization, a new method is developed to put various constraints on the mapping. These include alternative ways to perform the histogram calculations and how to define the local histograms. The new method also includes collimator detection and background suppression to keep irrelevant parts of the image out of the calculations. Results show that the new method enables proper display of both underexposed and overexposed areas in the image simultaneously while maintaining the natural look of the image. More testing is required to find appropriate parameters for various image types.</p>
50

A novel method of generating Dendritic cells in vitro using the KG-1 cell line and its use as a model for testing effects of lactic acid bacteria

Vidya, Parimala 01 August 2011 (has links)
Dendritic cells (DCs) are prime mediators of innate and adaptive immunity. In humans the DC population comprise only 0.1% of all leukocytes, making their isolation and ex vivo manipulation difficult. Since study of DC activity in vitro requires large numbers of DCs to be readily available, a cell line model, KG-1, was selected. KG-1 cells are a cytokine-responsive human CD34+ myelomonocytic cell line and can be induced to differentiate to a DC phenotype. A range of differentiation agents and protocols were compared, and differentiation efficiency was determined using both morphological features and cell surface marker expression. Expression of CD83, CD11c, CD123, CD86, HLA-DR and DC-SIGN was assessed by immunofluorescence and flow cytometry. KG-1 cells stimulated with 10 ng/ml PMA and 100 ng/ml Ionomycin were found to be the ideal model for obtaining Dendritic Like Cells (DLCs) in vitro. The effect of lactic acid bacteria on KG-1 differentiation was also tested using two immunomodulatory strains, Lactobacillus rhamnosus R0011 and Lactobacillus helveticus R0052. After 5 days of incubation with R0011 the KG-1 cells expressed DC-specific surface markers CD83, CD86, CD11c, CD123, DC-SIGN and HLA-DR. Lactobacillus rhamnosus R0011 induced a marked rise in CD83 expression with a mean fluorescence intensity of 115.3 after 5 days, suggesting this strain promoted KG-1 differentiation to DLC. Analysis of cytokine by KG-1 DLC indicated that constitutive production of pro-inflammatory cytokines TNF-α and IL-12 was minimal. However IL-10 and TGF-β were detected after TLR-agonist stimulation of R0011-differentiated KG-1s. This study aimed to develop and assess the KG-1 cell model for screening effects of mediators and microbes on DC. / UOIT

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