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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.
21

Estudo e análise sobre métodos de interpolação de imagens bidimensionais / The study and analysis of bidimensional images interpolation methods

Pinheiro, Rogerio Voges January 1994 (has links)
Este trabalho apresenta um estudo sobre métodos utilizados para realizar metamorfose entre imagens digitais. Segundo esses métodos é possível estabelecer uma imagem fonte, uma destino e, através de operações de mapeamento de texturas, realizar uma seqüência de imagens intermediárias. Essas imagens intermediárias apresentam-se como deformações sobre a imagem fonte ou como etapas de transição entre as imagens originais, efeito produzido pela inserção de um processo de fusão de imagens. O processo de deformação varia segundo o método empregado e influencia diretamente nos resultados por ele gerado. Assim, dois métodos com características diferentes para deformação de imagens foram escolhidos, dentre os encontrados, para um estudo mais aprofundado e são referenciados como o Método das Malhas e o Método dos Campos de Influência. Esses métodos são apresentados, seus funcionamentos discutidos e resultados gerados para se estabelecer uma análise entre os mesmos. A análise é efetuada segundo os aspectos de tempo de processamento, consumo de minoria e atribuição de correspondências entre as imagens, sendo que esta última característica leva em consideração o tempo total gasto para se estabelecer as correspondências necessárias entre a imagem fonte e a destino. Neste ponto também é estabelecido um quadro comparativo entre os métodos escolhidos, destacando-se vantagens e desvantagens. Os resultados da aplicação dos métodos analisados encontram-se distribuídos ao longo do texto sob a forma de imagens e tabelas, são utilizados para provar a eficiência desses métodos e foram gerados por um sistema de testes implementado. O sistema de testes desenvolvido possibilita a geração de imagens, segundo o método escolhido, informa os tempos utilizados no processamento e exibe essas imagens seqüencialmente sob a forma de uma animação. Por fim o trabalho apresenta conclusões sobre o estudo, salientando aspectos considerados relevantes quando do estudo e implementação dos métodos, e indica futuras extensões que podem ser efetuadas a fim de tornar o sistema de testes mais flexível e completo. / This work presents a study on methods used to make digital images metamorphosis. According to these methods it is possible to establish a source image, a destination image and also to generate a sequence of intermediate images through operations of texture mapping. These intermediate images appears as deformations of the source image or as transition steps between the original images which are produced by the insertion of a cross-dissolve process. The warping process varies according to the method which is used and it influences directly its results. Thus, two methods for image warping with different characteristics were chosen, among the available ones, for a more detailed study and are refered as the Mesh Method and as the Fields of Influence Method. These two methods are presented, their functioning is discussed and results are generated to allow comparative analyses. The analysis concerns aspects of processing time, memory allocation and correspondence establishment, which take into account the time waisted in order to establish the correspondences between the images. At this point it is also established a comparative table between the chosen methods highlighting advantages and disadvantages. The results of the application of the analysed methods are distributed throughout the text as images and tables, which are used to prove the efficiency of them and were generated by a test system implemented. The system developed provides the generation of images, according to the choosen method, informs the time waisted on processing and shows those images sequentially as an animation. Finally this work presents conclusions about the study and indicates future extensions that can be done in order to make the developed system more flexible and complete.
22

Estudo e análise sobre métodos de interpolação de imagens bidimensionais / The study and analysis of bidimensional images interpolation methods

Pinheiro, Rogerio Voges January 1994 (has links)
Este trabalho apresenta um estudo sobre métodos utilizados para realizar metamorfose entre imagens digitais. Segundo esses métodos é possível estabelecer uma imagem fonte, uma destino e, através de operações de mapeamento de texturas, realizar uma seqüência de imagens intermediárias. Essas imagens intermediárias apresentam-se como deformações sobre a imagem fonte ou como etapas de transição entre as imagens originais, efeito produzido pela inserção de um processo de fusão de imagens. O processo de deformação varia segundo o método empregado e influencia diretamente nos resultados por ele gerado. Assim, dois métodos com características diferentes para deformação de imagens foram escolhidos, dentre os encontrados, para um estudo mais aprofundado e são referenciados como o Método das Malhas e o Método dos Campos de Influência. Esses métodos são apresentados, seus funcionamentos discutidos e resultados gerados para se estabelecer uma análise entre os mesmos. A análise é efetuada segundo os aspectos de tempo de processamento, consumo de minoria e atribuição de correspondências entre as imagens, sendo que esta última característica leva em consideração o tempo total gasto para se estabelecer as correspondências necessárias entre a imagem fonte e a destino. Neste ponto também é estabelecido um quadro comparativo entre os métodos escolhidos, destacando-se vantagens e desvantagens. Os resultados da aplicação dos métodos analisados encontram-se distribuídos ao longo do texto sob a forma de imagens e tabelas, são utilizados para provar a eficiência desses métodos e foram gerados por um sistema de testes implementado. O sistema de testes desenvolvido possibilita a geração de imagens, segundo o método escolhido, informa os tempos utilizados no processamento e exibe essas imagens seqüencialmente sob a forma de uma animação. Por fim o trabalho apresenta conclusões sobre o estudo, salientando aspectos considerados relevantes quando do estudo e implementação dos métodos, e indica futuras extensões que podem ser efetuadas a fim de tornar o sistema de testes mais flexível e completo. / This work presents a study on methods used to make digital images metamorphosis. According to these methods it is possible to establish a source image, a destination image and also to generate a sequence of intermediate images through operations of texture mapping. These intermediate images appears as deformations of the source image or as transition steps between the original images which are produced by the insertion of a cross-dissolve process. The warping process varies according to the method which is used and it influences directly its results. Thus, two methods for image warping with different characteristics were chosen, among the available ones, for a more detailed study and are refered as the Mesh Method and as the Fields of Influence Method. These two methods are presented, their functioning is discussed and results are generated to allow comparative analyses. The analysis concerns aspects of processing time, memory allocation and correspondence establishment, which take into account the time waisted in order to establish the correspondences between the images. At this point it is also established a comparative table between the chosen methods highlighting advantages and disadvantages. The results of the application of the analysed methods are distributed throughout the text as images and tables, which are used to prove the efficiency of them and were generated by a test system implemented. The system developed provides the generation of images, according to the choosen method, informs the time waisted on processing and shows those images sequentially as an animation. Finally this work presents conclusions about the study and indicates future extensions that can be done in order to make the developed system more flexible and complete.
23

Evaluation of Image Warping Algorithms for Implementation in FPGA

Serguienko, Anton January 2008 (has links)
The target of this master thesis is to evaluate the Image Warping technique and propose a possible design for an implementation in FPGA. The Image Warping is widely used in the image processing for image correction and rectification. A DSP is a usual choice for implantation of the image processing algorithms, but to decrease a cost of the target system it was proposed to use an FPGA for implementation. In this work a different Image Warping methods was evaluated in terms of performance, produced image quality, complexity and design size. Also, considering that it is not only Image Warping algorithm which will be implemented on the target system, it was important to estimate a possible memory bandwidth used by the proposed design. The evaluation was done by implemented a C-model of the proposed design with a finite datapath to simulate hardware implementation as close as possible.
24

Design, modelling and optimisation of morphing structures for medium altitude long endurance UAVs

Ajaj, Rafic Mohammad January 2013 (has links)
No description available.
25

Design and Implementation of Video View Synthesis for the Cloud

Pouladzadeh, Parvaneh January 2017 (has links)
In multi-view video applications, view synthesis is a computationally intensive task that needs to be done correctly and efficiently in order to deliver a seamless user experience. In order to provide fast and efficient view synthesis, in this thesis, we present a cloud-based implementation that will be especially beneficial to mobile users whose devices may not be powerful enough for high quality view synthesis. Our proposed implementation balances the view synthesis algorithm’s components across multiple threads and utilizes the computational capacity of modern CPUs for faster and higher quality view synthesis. For arbitrary view generation, we utilize the depth map of the scene from the cameras’ viewpoint and estimate the depth information conceived from the virtual camera. The estimated depth is then used in a backward direction to warp the cameras’ image onto the virtual view. Finally, we use a depth-aided inpainting strategy for the rendering step to reduce the effect of disocclusion regions (holes) and to paint the missing pixels. For our cloud implementation, we employed an automatic scaling feature to offer elasticity in order to adapt the service load according to the fluctuating user demands. Our performance results using 4 multi-view videos over 2 different scenarios show that our proposed system achieves average improvement of 3x speedup, 87% efficiency, and 90% CPU utilization for the parallelizable parts of the algorithm.
26

Defect Detection in Selective Laser Melting

Foster, Moira 01 June 2018 (has links) (PDF)
Additively manufactured parts produced using selective laser melting (SLM) are prone to defects created during the build process due to part shrinkage while cooling. Currently defects are found only after the part is removed from the printer. To determine whether cracks can be detected before a print is completed, this project developed print parameters to print a test coupon with inherent defects – warpage and cracking. Data recorded during the build was then characterized to determine when the defects occurred. The test coupon was printed using two sets of print parameters developed to control the severity of warpage and cracking. The builds were monitored using an accelerometer recording at 12500 samples per second, an iphone recording audio at 48000 samples a second, and a camera taking a photo every build layer. Data was analyzed using image comparison, signal amplitude, Fourier Transform, and Wavelet Decomposition. The developed print parameters reduced warpage in the part by better distributing heat throughout the build envelope. Reducing warpage enabled the lower portion of the part to be printed intact, preserving it to experience cracking later in the build. From physical evidence on the part as well as time stamps from the machine script, several high energy impulse events in the accelerometer data were determined to be when cracking occurred in the build. This project’s preliminary investigation of accelerometers to detect defects in selective laser melting will be used in future work to create machine learning algorithms that would control the machine in real time and address defects as they arise.
27

Denial of service detection using dynamic time warping

Diab, D.M., AsSadhan, B., Binsalleeh, H., Lambotharan, S., Kyriakopoulos, K.G., Ghafir, Ibrahim 18 April 2021 (has links)
Yes / With the rapid growth of security threats in computer networks, the need for developing efficient security‐warning systems is substantially increasing. Distributed denial‐of‐service (DDoS) and DoS attacks are still among the most effective and dreadful attacks that require robust detection. In this work, we propose a new method to detect TCP DoS/DDoS attacks. Since analyzing network traffic is a promising approach, our proposed method utilizes network traffic by decomposing the TCP traffic into control and data planes and exploiting the dynamic time warping (DTW) algorithm for aligning these two planes with respect to the minimum Euclidean distance. By demonstrating that the distance between the control and data planes is considerably small for benign traffic, we exploit this characteristic for detecting attacks as outliers. An adaptive thresholding scheme is implemented by adjusting the value of the threshold in accordance with the local statistics of the median absolute deviation (MAD) of the distances between the two planes. We demonstrate the efficacy of the proposed method for detecting DoS/DDoS attacks by analyzing traffic data obtained from publicly available datasets. / The Deanship of Scientific Research, King Saud University. The Gulf Science, Innovation, and Knowledge Economy Programme of the U.K. Government
28

Deciphering Emotional Responses to Music: A Fusion of Psychophysiological Data Analysis and Bi-LSTM Predictive Modeling

Mahat, Maheep 10 June 2024 (has links)
This research explores the temporal patterns of psychophysiological responses to musical excerpts by analyzing the expansive Emotion in Motion dataset, the most comprehensive of its kind. Utilizing the Dynamic Time Warping and T-test analysis techniques, we examined data from participants across seven countries who listened to three distinct musical pieces. During these listening sessions, Electrodermal Activity (EDA) and Pulse Oximetry (POX) readings were collected, complemented by qualitative feedback from the participants. Our analysis focused on detecting recurring patterns and extracting meaningful insights from the data. In addition to this, we compare several Deep Neural Networks to find the one that is best suited for prediction of emotional attributes with EDA and POX signals as input. To further facilitate a comprehensive visualization and analysis of the EDA, POX, and audio signals, we developed a dedicated platform, which features a coordinated multiple view interface, as an integral part of this work. / Master of Science / We explored how people's bodies react over time when they listen to music. We used a large collection of data called the ``Emotion in Motion'' dataset, which has information from people in seven countries who listened to three different music pieces. To understand this data, we used special tools that help detect patterns and changes in how the body responds. During the music sessions, the participant's skin's electrical activity and the amount of oxygen in the blood were recorded, which can give clues about emotional reactions. People also shared their feelings about the music. To make it easier to see and understand all this information together, we created a new web platform that simulates the experiment in real-time. This work aims to help us better understand the deep connection between music and human emotions.
29

Combine Shapelets

Qingwen, Zeng 01 April 2024 (has links) (PDF)
Sensor-based human activity recognition has become an important research field within pervasive and ubiquitous computing. Techniques for recognizing atomic activities such as gestures or actions are mature for now, but complex activity recognition still remains a challenging issue. I was a candidate in an activity classification thesis. It collected 4 activities, which included walking on the sidewalk for a set distance, walking up and down a set of stairs, walking on the treadmill at 2.5 mph for 2 minutes, and jogging on the treadmill at 5.5 mph for 1 minute. It took 30 minutes to collect one candidate data. If complex activity data can be made up with atomic activities data, the data collecting process will be simplified. In this thesis, I used methods to mimic a complex activity shapelet by combing atomic activity shapelets. I first collect two candidates walk, jump and skip time series data, in which walk and jump are considered the atomic activities of skip. Time series patterns, shapelets, are extracted using tsshapelet package. Shapelets are small sub-series, or parts of the time-series, that are informative or discriminative for a certain class. They can be used to transform the time-series to features by calculating the distance for each of the time-series you want to classify to a shapelet. In order to create skip representative shapelet, Barycenter Dynamic Time Warping and Weighted Dynamic Time Warping are used to average walk and jump shapelet, and then compare the euclidean distance between skip shapelet with walk shapelet, jump shapelet and, combined-shapelet. Experimental result show that the combined-shapelet is closer to skip shapelet than single walk or jump shapelet. Then I use three evaluation methods to mathematically and statistically show that combined-shapelet and real skip shapelet are similar. Evaluation methods include sliding window, cycle comparison and random comparison. To verify whether combined-shapelet can substitute real skip shapelet, a new labeled time series data is introduced, the result shows that both shapelets have the label accuracy around 70%, accuracy difference is less than 1%.
30

Time warped continuous speech signal matching using Kalman filter

Khan, Wasiq, Holton, Robert January 2015 (has links)
No / Dynamic speech properties, such as time warping, silence removal and background noise reduction are the most challenging issues in continuous speech signal matching. Among all of them, the time warped speech signal matching is of great interest and has been a tough challenge for the researchers. The literature contains a variety of techniques to measure the similarity between speech utterances, however there are some limitations associated with these techniques. This paper introduces an adaptive framing based continuous speech tracking and similarity measurement approach that uses a Kalman filter (KF) as a robust tracker. The use of KF is novel for time warped speech signal matching and dynamic time warping. A dynamic state model is presented based on equations of linear motion. In this model, fixed length frame of input (test) speech signal is considered as a unidirectional moving object by sliding it along the template speech signal. The best matched position estimate in template speech (sample number) for corresponding test frame at current time is calculated. Simultaneously, another position observation is produced by a feature based distance metric. The position estimated by the state model is fused with the observation using KF along with the noise variances. The best estimated frame position in the template speech for the current state is calculated. Finally, forecasting of the noise variances and template frame size for next state are made according to the KF output. The experimental results demonstrate the robustness of the proposed technique in terms of time warped speech signal matching as well as in computation cost.

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