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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.
361

Design and Analysis of a Real-time Data Monitoring Prototype for the LWA Radio Telescope

Vigraham, Sushrutha 11 March 2011 (has links)
Increasing computing power has been helping researchers understand many complex scientific problems. Scientific computing helps to model and visualize complex processes such as molecular modelling, medical imaging, astrophysics and space exploration by processing large set of data streams collected through sensors or cameras. This produces a massive amount of data which consume a large amount of processing and storage resources. Monitoring the data streams and filtering unwanted information will enable efficient use of the available resources. This thesis proposes a data-centric system that can monitor high-speed data streams in real-time. The proposed system provides a flexible environment where users can plug-in application-specific data monitoring algorithms. The Long Wavelength Array telescope (LWA) is an astronomical apparatus that works with high speed data streams, and the proposed data-centric platform is developed to evaluate FPGAs to implement data monitoring algorithms in LWA. The throughput of the data-centric system has been modeled and it is observed that the developed data-centric system can deliver a maximum throughput of 164 MB/s. / Master of Science
362

NextBrowse: An integrated and interactive web-based genome browser for analyzing and interpreting genomic data

Whisenhunt, Phillip J. 29 May 2012 (has links)
With the advent of high throughput sequencing technologies over the past decade there has been a surge in the amount of genomic data that needs to be analyzed and interpreted. Despite the availability of software frameworks such as the Genome Analysis Toolkit, data interpretation and analysis still requires human intervention and refinement. Genome browsers enable developers and users of sequence analysis tools to visualize, compare, and better interpret genomic data such as gene expression and functional annotations. We developed a next generation cross platform web-based genome browser, NextBrowse, for visualizing General Feature Format and Binary Alignment Map files. NextBrowse uses advanced visualization techniques such as 3D feature selection and transparency based on mapping quality, and improved Graphical User Interface elements such as individual track searching and textual and graphical reference location. NextBrowse is the first genome browser to allow BAM files to be streamed and visualized, the first genome browser to employ security measures, and the first to use only client side rendering. NextBrowse takes advantage of the open-source community, allowing developers and users to extend the project to fit their needs. NextBrowse along with all documentation is available for use at http://www.nextbrowse.vbi.vt.edu. / Master of Science
363

Evaluation of Spectrum Data Compression Algorithms for Edge-Applications in Industrial Tools

Ring, Johanna January 2024 (has links)
Data volume is growing for each day as more and more is digitalized which puts the data management on test. The smart tools developed by Atlas Copco saves and transmits data to the cloud as a service to find errors in tightening's for their customers to review. A problem is the amount of data that is lost in this process. A tightening cycle usually contains thousands of data points and the storage space for it is too great for the tool's hardware. Today many of the data points are deleted and a small portion of scattered data of the cycle is saved and transmitted. To avoid overfilling the storage space the data need to be minimized. This study is focus on comparing data compression algorithms that could solve this problem.   In a literature study in the beginning, numerous data compression algorithms were found with their advantages and disadvantages. Two different types of compression algorithms are also defined as lossy compression, where data is compressed by losing data points or precision, and lossless compression, where no data is lost throughout the compression. Two lossy and two lossless algorithms are selected to be avaluated with respect to their compression ratio, speed and error tolerance. Poor Man's Compression - Midrange (PMC-MR) and SWING-filter are the lossy algorithms while Gorilla and Fixed-Point Compression (FPC) are the lossless ones.   The reached compression ratios, in percentage, could range from 39\% to 99\%. As combinations of a lossy and a lossless algorithm yields best compression ratios with lower error tolerance, PMC-MR with Gorilla is suggested to be the best suited for Atlas Copco's needs.
364

A Contribution to Video Streaming Quality and Energy Efficiency in Optical and Ethernet Networks

Vargas Hernández, Tito Raúl 18 April 2023 (has links)
[ES] La distribución de contenidos multimedia, tanto a través de Internet como de redes gestionadas dedicadas exclusivamente a este fin, está teniendo una mayor cuota del tráfico total y crece cada día, especialmente el servicio de vídeo streaming. Por ello, ha surgido el interés de investigar para mantener y mejorar la Calidad de Servicio (QoS) en redes de acceso y backbone, y ofrecer Calidad de Experiencia (QoE) a los usuarios finales; mediante el ajuste de parámetros, configuraciones, protocolos y algoritmos a los requerimientos de la red en cuanto a la alta demanda de tráfico de vídeo. Lo anterior aprovechando al máximo los recursos de la red, tanto en el núcleo y las redes de acceso, como el ancho de banda y la capacidad total instalada, y al mismo tiempo, proponiendo alternativas de transporte eficientes para el tráfico de vídeo agregado sin incrementar los costos de los servicios; y alternativas para reducir los costos operativos y gastos de mantenimiento de manera eficiente, como por ejemplo la reducción del consumo de energía. En primer lugar, esta tesis aborda el estudio de propuestas de conmutación óptica en redes troncales y la distribución de contenidos multimedia, particularmente la propuesta de Red de Conmutación Óptica de Ráfagas (OBS) desde el punto de vista de la Ingeniería Telemática. Por lo tanto, se estudia la arquitectura, protocolos y algoritmos de estas redes para hacer aportes a la evaluación del tráfico de vídeo y alternativas para ofrecer QoS y QoE para el tráfico multimedia. En este sentido, este trabajo contribuye con propuestas para la evaluación de la calidad mediante simulación utilizando trazas de transmisiones de vídeo reales, y propuestas de algoritmos de scheduling y ensamblaje de ráfagas ópticas para ofrecer QoS y QoE al tráfico de vídeo en las redes OBS. En segundo lugar, se estudian los patrones de tráfico de vídeo a nivel de aplicación y de red para caracterizarlos y realizar estudios de eficiencia energética y ahorro de consumo energético en las tarjetas de red utilizadas por servidores de vídeo en streaming y clientes que implementan el estándar IEEE 802.3az Energy Efficient Ethernet (EEE), tanto en redes gestionadas, como IPTV que implementa transmisión de vídeo RTP, como en redes no gestionadas, como Internet, que implementa el estándar Dynamic Adaptive Streaming over HTTP (DASH) para servicios Over The Top (OTT). Para alcanzar este objetivo, se implementan testbeds y se llevan a cabo experimentos para concluir cómo el tráfico de vídeo podría beneficiarse de la eficiencia energética y lograr una reducción a gran escala en el consumo de energía si el estándar EEE se implementa a nivel mundial en las tarjetas Ethernet de los dispositivos involucrados en la distribución de vídeo. El tema integrador que se aborda en esta tesis es la distribución de vídeo digital. Por lo tanto, este trabajo también presenta un estudio sobre la codificación y adaptación de transmisión de vídeo en redes IP, presentando aspectos relacionados con la evaluación de la calidad de vídeo y la evaluación de la calidad de transmisión de la red. Por ello, se proponen e implementan metodologías y bancos de pruebas que involucran la programación y ejecución de simuladores, scripts, algoritmos, software y, en general, frameworks para realizar estudios de transmisiones de vídeo en redes de telecomunicaciones, cubriendo el amplio espectro de las Comunicaciones Multimedia. Este estudio podría ser de utilidad para emprender otros estudios necesarios ante la rápida evolución tanto de la demanda de servicios multimedia como de las propuestas de nuevas técnicas de distribución de contenidos. / [CAT] La distribució de continguts multimèdia, a través d'Internet i a través de xarxes gestionades dedicades exclusivament a aquesta finalitat, està tenint una part més gran del trànsit total i augmenta cada dia, especialment el servei de streaming de vídeo. Per tant, ha sorgit l'interés de la recerca per mantenir i millorar la Qualitat de Servei (QoS) en les xarxes d'accés i troncals, i per oferir Qualitat d'Experiència (QoE) als usuaris finals, ajustant paràmetres, configuracions, protocols i algoritmes als requeriments de la xarxa pel que fa a l'alta demanda de trànsit de vídeo. Aquest últim, aprofitant al màxim els recursos de xarxa al nucli i a les xarxes d'accés, com ara l'amplada de banda i la capacitat instal·lada total, i alhora, proposant alternatives de transport eficients per al trànsit agregat de vídeo sense augmentar els costos dels serveis i alternatives per reduir les despeses operatives i de manteniment d'una manera eficient, com ara reduir el consum d'energia. En primer lloc, aquesta tesi tracta l'estudi de les propostes de commutació òptica en xarxes troncals pel que fa a la distribució de continguts multimèdia, especialment l'estudi de la proposta de xarxes de commutació de ràfegues òptiques (OBS) des del punt de vista de l'Enginyeria Telemàtica. Per tant, s'estudia l'arquitectura, els protocols i els algoritmes d'aquestes xarxes per fer contribucions a l'avaluació del trànsit de vídeo i alternatives per oferir QoS i QoE per al trànsit multimèdia. En aquest sentit, aquest treball contribueix amb propostes per a l'avaluació de la qualitat mitjançant la simulació utilitzant traces de transmissions de vídeo reals, i propostes d'algoritmes de programació i muntatge de ràfegues òptiques per oferir QoS i QoE al trànsit de vídeo a les xarxes OBS. En segon lloc, s'estudien els patrons de trànsit de vídeo a nivell d'aplicació i xarxa per caracteritzar-los i realitzar estudis sobre eficiència energètica i estalvi energètic en les targetes de xarxa utilitzades pels servidors i clients de vídeo en streaming que implementen l'IEEE 802.3az Energy Efficient Ethernet (EEE) estàndard, tant en xarxes gestionades com IPTV, que implementa la transmissió de vídeo RTP, com en xarxes no gestionades com Internet, que implementa l'estàndard Dynamic Adaptive Streaming sobre HTTP (DASH) per als serveis Over The Top (OTT). Per assolir aquest objectiu, s'implementen bancs de proves i es realitzen experiments per concloure com el trànsit de vídeo podria beneficiar l'eficiència energètica i aconseguir una reducció a gran escala del consum d'energia si s'implementa l'estàndard EEE a les targetes Ethernet dels dispositius implicats en la distribución de vídeo. El tema integrador que s'aborda en aquesta tesi és la distribució de vídeo digital, per tant, aquest treball també presenta un estudi sobre la codificació i adaptació de la transmissió de vídeo a les xarxes IP, presentant aspectes relacionats amb l'avaluació de la qualitat del vídeo i l'avaluació de la qualitat de la transmissió de la xarxa. Per això, es proposen i s'implementen metodologies i bancs de proves que impliquen la programació i execució de simuladors, scripts, algoritmes, programari i, en general, frameworks per a la realització d'estudis de transmissions de vídeo en xarxes de telecomunicacions, abastant l'ampli espectre de les Comunicacions Multimèdia. Aquest estudi podria ser útil per emprendre altres estudis necessaris en la ràpida evolució tant de la demanda de serveis multimèdia com de les noves propostes de tècniques de distribució de continguts. / [EN] Multimedia content distribution, both over the Internet and over managed networks dedicated exclusively for this purpose, is having a greater share of total traffic and it is raising every day, especially the video streaming service. Therefore, research interest has arisen to maintain and improve the Quality of Service (QoS) in access and backbone networks, and to offer Quality of Experience (QoE) to end users, by adjusting parameters, configurations, protocols and algorithms to the network requirements regarding the video traffic high demand. The latter is carried out taking full advantage of the network resources at core and access networks such as bandwidth and total installed capacity, and at the same time, proposing efficient transportation alternatives for the aggregated video traffic without increasing services costs and alternatives to reduce operational and maintenance expenditures in an efficient manner, such as reducing the energy consumption. In the first place, this thesis deals with the study of optical switching proposals in backbone networks regarding multimedia content distribution, particularly studying the Optical Bursts Switching (OBS) Networks proposal from the Telematics Engineering point of view. Therefore, architecture, protocols and algorithms of these networks are studied to make contributions to the video traffic evaluation and alternatives to offer QoS and QoE for multimedia traffic. In this sense, this work contributes with proposals for the evaluation of quality through simulation using traces of real video transmissions, and optical burst assembly and scheduling algorithms proposals to offer QoS and QoE to video traffic in the OBS networks. Secondly, video traffic patterns at the application and network level are studied to characterize them and carry out studies on energy efficiency and energy consumption savings in the network cards used by streaming video servers and clients that implement the IEEE 802.3az Energy Efficient Ethernet (EEE) standard, both in managed networks, such as IPTV that implements RTP video streaming, and unmanaged networks, such as Internet which implements Dynamic Adaptive Streaming over HTTP (DASH) standard for Over The Top (OTT) services. To reach this goal, testbeds are implemented, and experiments are carried out to conclude how video traffic could benefit from the energy efficiency and achieve a large-scale reduction in energy consumption if the EEE standard is implemented word wide in the Ethernet cards of devices involved in video distribution. The integrating subject that is addressed in this thesis is the distribution of digital video. Therefore, this work also presents a study on the IP networks video transmission encoding and adaptation, presenting aspects regard the video quality evaluation and the network transmission quality assessment. Therefore, methodologies and testbeds are proposed and implemented that involves programming and execution of simulators, scripts, algorithms, software and, in general, frameworks to carry out studies for video transmissions in telecommunications networks, covering the broad spectrum of Multimedia Communications. This study could be useful to undertake other necessary studies in the rapid evolution of both, multimedia services demand and new content distribution techniques proposals. / Vargas Hernández, TR. (2023). A Contribution to Video Streaming Quality and Energy Efficiency in Optical and Ethernet Networks [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/192760
365

Automatic Generation of Efficient Parallel Streaming Structures for Hardware Implementation

Koehn, Thaddeus E. 30 November 2016 (has links)
Digital signal processing systems demand higher computational performance and more operations per second than ever before, and this trend is not expected to end any time soon. Processing architectures must adapt in order to meet these demands. The two techniques most prevalent for achieving throughput constraints are parallel processing and stream processing. By combining these techniques, significant throughput improvements have been achieved. These preliminary results apply to specific applications, and general tools for automation are in their infancy. In this dissertation techniques are developed to automatically generate efficient parallel streaming hardware architectures. / Ph. D. / The algorithms that process data have been getting more complicated requiring more operations in less time. This trend has been going on for many years with no end in sight. Techniques must be developed to allow the processing system to meet these requirements. Assembly line techniques, or stream processing allows multiple stages in which each stage is working on a different piece of data. Increasing the number of assembly lines can further increase the number of operations, but results in large overheads. This dissertation develops automation techniques to reduce these overheads resulting in efficient hardware.
366

Varför ser vi på spelstreams? : En kvalitativ intervjustudie av motivationen bakom att se på spelstreams

Lindström, Martin, Chowdhury, Arman January 2017 (has links)
Varför sitter människor i flera timmar och tittar på när någon annan spelar ett dator/tv-spel? Idag har spelstreaming vuxit sig stort och flera miljoner väljer att titta på spelandet. I vår undersökning kommer vi att svara på vad som motiverar vissa människor att titta på spelstreams genom en kvalitativ intervjustudie. Från den data som vi samlar in från intervjuer tar vi ut de motivationsfaktorer som nämns och delar in dem i fem behovskategorier: cognitive, affective, personal integrative, social integrative samt tension release. Genom vår studie så blev det klart att samma person kan titta på spelstreams vid olika tillfällen, med olika motiv. De två absolutvanligaste motiven till att se på spelstreams var underhållning och att lära sig något. / Why do people sit for hours to watch someone else play a videogame? Today gamingstreaming has grown large and millions of people choose to watch others play games. In our study we will answer what motivates people to watch gamingstreams through a qualitative interview study. From the data that we collect through interviews we will extract the motivationsfactors mentioned and sort them by five need-categories: cognitive, affective, personal integrative, social integrative and tension release. Our study showed that the same person can watch gamingstreams with different motives at different times. The two most common motives for watching thestreams was entertainment and learning something new.
367

Streamování počítačových her v České republice: kvalitativní studie / Live streaming of computer games in the Czech republic: a qualitative study

Válek, Jiří January 2015 (has links)
This thesis focuses on the phenomenon of live-streaming of computer games in the Czech Republic. This thesis is based on an approach of online ethnography and tries to describe what meaning do the producers of content (who are labeled as performers in this thesis) ascribe to streaming, what are their motivations to stream, how they present themselves on the streams and what is the content of those streams. The live-streaming of computer games in this thesis is put into context of user-generated content. The main part of this thesis is a qualitative research realized through an online observations of streams and through interviews with the performers, who stream on the streaming service Twitch. The findings show that streaming is entertaining and time passing activity for the performers, but also a form of a social contact. Some motivations of the performers include the satisfaction of their viewers and recurring contact with them. There were no financial motivations involved among the performers. Performers mostly do not stylize themselves into any specific role, however some of them do take on themselves the roles of teachers, who teach their viewers to be a better gamer, or the roles of entertainers. During the stream the performers mostly put their attention to only a single game and also to an...
368

Streamingtjänsternas inverkan på det linjära TV-tittandet : En undersökning om tittandemönster och värdet i tillsammanstittande

Thor, Christoffer, Otterstål, Fredrik January 2016 (has links)
The purpose of this essay is to study whether streaming services has made a difference in the act of viewing linear TV together with others. The methods used in the research are: a focus group performed with six people, an email-interview with an expert in TV and a general survey used to define the user groups. The results shows that streaming services has had an impact on viewing patterns and also contributed with new ones. The Swedish consumer is more likely to use streaming services everyday except for Fridays, which can be attributed to a tradition called Fredagsmys (friday cosiness), co-viewing primetime TV on Fridays. Co-viewing TV is also affected by streaming services according to our studies, but not nearly as much as the viewing behaviours. We’re using a theory called Diffusion of Innovation to explain the usage of streaming services and why it has not been adopted by everyone as their main platform for viewing media.
369

Streaming Video over Unreliable and Bandwidth Limited Networks

Aziz, Hussein January 2013 (has links)
The main objective of this thesis is to provide a smooth video playout on the mobile device over wireless networks. The parameters that specify the wireless channel include: bandwidth variation, frame losses, and outage time. These parameters may affect the quality of the video negatively, and the mobile users may notice sudden stops during the playout video, i.e., the picture is momentarily frozen, followed by a jump from one scene to a different one. This thesis focuses on eliminating frozen pictures and reducing the amount of video data that need to be transmitted. In order to eliminate frozen scenes on the mobile screen, we propose three different techniques. In the first technique, the video frames are split into sub-frames; these sub-frames are streamed over different channels. In the second technique the sub-frames will be “crossed” and sent together with other sub-frames that are from different positions in the streaming video sequence. If some sub-frames are lost during the transmission a reconstruction mechanism will be applied on the mobile device to recreate the missing sub-frames. In the third technique, we propose a Time Interleaving Robust Streaming (TIRS) technique to stream the video frames in different order. The benefit of that is to avoid losing a sequence of neighbouring frames. A missing frame from the streaming video will be reconstructed based on the surrounding frames on the mobile device. In order to reduce the amount of video data that are streamed over limited bandwidth channels, we propose two different techniques. These two techniques are based on identifying and extracting a high motion region of the video frames. We call this the Region Of Interest (ROI); the other parts of the video frames are called the non-Region Of Interest (non-ROI). The ROI is transmitted with high quality, whereas the non-ROI is interpolated from a number of references frames. In the first technique the ROI is a fixed size region; we considered four different types of ROI and three different scenarios. The scenarios are based on the position of the reference frames in the streaming frame sequence. In the second technique the ROI is identified based on the motion in the video frames, therefore the size, position, and shape of the ROI will be different from one video to another according to the video characteristic. The videos are coded using ffmpeg to study the effect of the proposed techniques on the encoding size. Subjective and objective metrics are used to measure the quality level of the reconstructed videos that are obtained from the proposed techniques. Mean Opinion Score (MOS) measurements are used as a subjective metric based on human opinions, while for objective metric the Structural Similarity (SSIM) index is used to compare the similarity between the original frames and the reconstructed frames.
370

Avaliação objetiva e subjetiva de qualidade de vídeo via rede IP com variação de atraso. / Objective and subjective assessment of video quality over IP network with packet delay variation.

Coaquira Begazo, Dante 04 October 2012 (has links)
Atualmente existe uma grande variedade de serviços de telecomunicações focados na transmissão de voz, vídeo e dados através de redes complexas, embora, em muitos casos, o usuário final não seja atendido com um nível de qualidade aceitável. Neste trabalho, se avalia como o serviço de streaming de vídeo em uma rede com protocolo Internet (IP) pode ser afetado por uma condição adversa da rede, tal como a variação de atraso (jitter). São mostrados os resultados de avaliações objetivas e subjetivas de streaming de vídeo que indicam que a qualidade de vídeo é diretamente afetada por fatores de degradação da rede IP como a variação de atraso de pacotes. Além disso, se verifica que cenas de maior movimento também são mais afetadas pela variação de atraso. Para a realização dos testes, utiliza-se um cenário de emulação de rede isolado, no qual são parametrizadas diferentes condições de rede. Assim, no canal de transmissão são configurados diversos valores de variação de atraso, obtendo-se uma Base de Dados de vídeos com diferentes graus de degradação de qualidade. Estes vídeos são avaliados utilizando métodos subjetivos: Índice por Categorias Absolutas (ACR - Absolute Category Rating) e Índice por Categorias de Degradação (DCR - Degradation Category Rating) e métricas objetivas: Relação Sinal-Ruído de Pico (PSNR - Peak Signal to Noise Ratio), Índice de Similaridade Estrutural (SSIM - Structural Similarity Index) e Medição de Qualidade de Vídeo (VQM - Video Quality Metric). Com a finalidade de mostrar o desempenho das métricas objetivas em relação às subjetivas são empregados os coeficientes de correlação, além do erro de predição e quadrático médio. Adicionalmente, é importante destacar que a partir dos resultados obtidos são estabelecidos intervalos de valores de variação de atraso para os quais a qualidade do vídeo é considerada aceitável ou não para o usuário final. Finalmente, obtém-se uma Base de Dados de vídeos com diferentes graus de degradação da qualidade e que pode ser utilizada em futuras pesquisas. / Nowadays, there is a wide range of telecommunications services focused on the transmission of voice, video and data across complex networks, although, in many cases, the end user is not satisfied with an acceptable quality level. In this work it is assessed how the video streaming service over an IP network can be affected by adverse conditions on the network, such as packet delay variation (jitter). Results from objective and subjective video streaming assessments are shown and indicate that the video quality is directly affected by IP network degradation factors such as packet delay variation. Beyond that, it is also verified that scenes with great movement content are also more sensitive to packet delay variation. For experimental tests, a network emulation totally isolated is considered, for which different network conditions are parameterized. Then, to the transmission channel, different values of packet delay variation are configured and videos are assessed, using subjective metrics: Absolute Category Rating (ACR) and Degradation Category Rating (DCR), and objective metrics: Peak Signal to Noise Ratio (PSNR), Structural Similarity (SSIM) and Video Quality Metric (VQM). In order to show the performance of objective metrics in relation to subjective ones correlation coefficients are employed as well as the prediction error and the mean square error. Finally, it is important to note that, from the results obtained, it can be established a range of delay variation values in which the video quality is acceptable or not at the end user. Additionally, a Video Data Base is obtained with different degrees of quality degradation and which can be used for future researches.

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