To see the other types of publications on this topic, follow the link: Video server.
Dissertations / Theses on the topic 'Video server'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Video server.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Daar, Waqas. "Distribution Agnostic Video Server." Thesis, KTH, School of Information and Communication Technology (ICT), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-24269.
Full textAbstract:
With the advances of network and communication technology, real time audio and video streaming services are becoming progressively popular over the Internet. In order to enable universal access of multimedia streaming content and thus the desired end-to-end QoS, it is very desirable to design a video server. A video server, that can dynamically coupled to dierent streaming engines and deployed in a test bed for conducting dierent streaming experiments.
In this thesis we present the design of a video server that implement an agnostic" experiments using dierent engines. Proposed video server is also deployed in a test bed for evaluating dierent performance measurement parameters like CPU load, memory utilization etc. The results of test bed also support our proposed idea and unfold many opportunities for the research community to perform dierent multimedia streaming experiments with proposed video server. "engine-abstraction that will help to automate and repeat deterministic streaming
2
Chang, He. "Server selection for heterogeneous cloud video services." HKBU Institutional Repository, 2017. http://repository.hkbu.edu.hk/etd_oa/419.
Full textAbstract:
Server selection is an important problem of cloud computing in which cloud service providers direct user demands to servers in one of the multiple data centers located in different geographical locations. The existing solutions usually assume homogeneity of cloud services (i.e., all users request the same type of service) and handle user demands in an individual basis which incurs high computational overhead. In this study, we propose a new and effective server selection scheme in which diversities of cloud services are taken into account. We focus on a specific cloud service, i.e., online video service, and assume that different videos have different bandwidth requirements. We group users into clusters and handle user demands on a cluster basis for faster and more efficient process. Firstly, we assume that user demands and bandwidth capacities of servers are given in the data centers, our problem is to assign the user demands to the servers under the bandwidth constraint, such that the overall latency (measured by the network distance) between the user clusters and the selected servers is minimized. We design a server selection system and formulate this problem as a linear programming formulation which can be solved by existing techniques. The system periodically executes our scheme and computes an optimal solution for server selection. User demands are assigned to the servers according to the optimal solution and the minimum overall latency can be achieved. The simulation results show that our scheme is significantly better than the random algorithm and the YouTube server selection strategy. Based on the first part, we take the storage capacities of servers constraint into consideration. In the second part, our new problem is to assign the user demands to the servers under the bandwidth and storage constraint, such that the function of overall latency (measured by the network distance) between the user clusters and the selected servers and standard deviation of traffic load of every server in the system is minimized. We design a server selection system and formulate this problem which can be solved by existing techniques. User demands are assigned to the servers according to the optimal solution and the two goals (minimum overall latency and the most balanced traffic load) can be achieved. The simulation results show the influence of different weights of these two goals on the user demands assigning.
3
Islam, Md Safiqul. "A HTTP Streaming Video Server with Dynamic Advertisement Splicing." Thesis, KTH, Kommunikationssystem, CoS, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91108.
Full textAbstract:
The Internet today is experiencing a large growth in the amount of traffic due to the number of users consuming streaming media. For both the operator and content providers, streaming of media generates most of its revenue through advertisements inserted in the content. One common approach is to pre-stitched (i.e. insert) advertisements into the content. Another approach is dynamic advertisement insertion, which inserts advertisements at run-time while the media is being streamed. Dynamic advertisement insertion gives operators the flexibility to insert advertisements based on context, such as the user's geographic location or the user's preferences. Developing a technique to successfully insert advertisements dynamically into the streaming media has several challenges, such as maintaining synchronization of the media, choosing the appropriate transport format for media delivery, and finding a splicing boundary that starts with a key frame. The details of these challenges are detailed in this thesis. We carried out extensive research to find the best transport format for delivery of media and we studied prior work in an effort to find an appropriate streaming solution to perform dynamic advertisement insertion. Based upon this research and our study of prior work we identify the best transport format for delivery of media chunks, then propose, implement, and evaluate a technique for advertisement insertion.Idag har internet mycket trafik på grund av att alltfler servrar erbjuder högkvalitativa videon som strömmas till internetanvändare. Både för operatörer och leverantörer av sådan innehåll genererar direktuppspelning mest intäkter genom annonser som lagts till i videon. Det är väldigt vanligt att lägga till annonser i videon genom att sy in dem i videofiler. En annan metod är att lägga till annonser dynamiskt. Det betyder att resulterande videofilen genereras medan den blir strömmad till användare. Att sätta in annonser dynamiskt har som fördel för operatörer att välja reklam beroende på kontexten, såsom användarens position eller preferenser. Det är utmanande att utveckla den teknik som krävs för att kunna sätta in annonser dynamiskt i strömmade videofiler. Till exempel är det viktigt att tänka på följande: synkronisering av strömmad innehåll, val av lämplig transportformat för videoleveransen och gränsen för skarvning (så kallad splicing boundary). Detaljerna kring denna teknik finns i denna avhandling. Vi har forskat på att hitta det bästa transportformatet för videoleverans och vi har studerat relevant arbete som gjorts tidigare för att hitta en lämplig mekanism för dynamisk annonsinsättning. Baserat på vår forskning och studerande av tidigare arbeten har vi klassificerat det bästa formatet för leveransen av videostycken, implementerat och evaluerat en teknik för annonsinlägg.
4
Qazzaz, Bahjat. "Admission Control and Media Delivery Subsystems for Video on Demand Proxy Server." Doctoral thesis, Universitat Autònoma de Barcelona, 2004. http://hdl.handle.net/10803/3045.
Full textAbstract:
El desarrollo y las avances recientes de la tecnología de los ordenadores y de la tecnología de alta velocidad de redes han hecho posible que las aplicaciones de video bajo demanda estén conectadas a "shared-computing" servidores reemplazando los sistemas tradicionales donde cada aplicación tenía su propia máquina dedicada para servirla. La aplicación de video bajo demanda permite a los usuarios seleccionar de una lista de videos su película favorita y ver su reproducción a su gusto.Sin embargo, la aplicación de video bajo demanda se considera como una de las aplicaciones que debería soportar largos "video streams", que consumen muchos recursos como el anch de banda de red y I/O, a gran número de clientes. Por eso, el servidor de video debería asegurar los recursos necesarios para cada "stream" durante un periodo de tiempo largo (e.g. 7200 segundos) para que los clientes reproduzcan el video sin "jitter" y "starvation" en sus búferes.
Esta tesis presenta el diseño y la implementación de un Servidor Proxy de Video (VPS) que puede proveer video bajo demanda interactiva. El VPS consiste de tres componentes (partes) principales. La primera parte es el Modulo de Control de Admisión (ACM) que recibe las peticiones de los clientes, negocia los recursos requeridos, y decide si la petición puede ser aceptada o rechazada basado en la disponibilidad de los recursos. La segunda parte es el Modulo de Manejo de los Recursos (RMM) que maneja los recursos del sistema como el CPU, la Memoria, la Red, y el Disco. Este consta de cuatro "brokers" que reservan a los recursos necesarios basado en una política predefinida. La tercera parte es el algoritmo CB_MDA "Credit_Based Media Delivery Algorithm" que controla y regula el flujo de los "streams" del video. La CB_MDA utiliza una combinación de canales unicast y "multicast" para transmitir el video. Los "streams" de "multicast" se inician para empezar a emitir el video desde el principio, mientras los canales unicast se usan para juntar los llegados tardes a un "stream multicast" apropiado. En la implementación, el CB_MDA detecta los momentos cuando el servidor tiene disponibilidad de recursos y les asigna a los usuarios apropiados para crear un trabajo en adelanto.
The recent advances and development of inexpensive computers and high speed networking technology have enabled the Video on Demand (VoD) application to connect to shared-computing servers, replacing the traditional computing environments where each application was having its own dedicated special purpose computing hardware. The VoD application enables the viewer to select, from a list of video files, his favourite video file and watch its reproduction at will.
However, the VoD application is known as one of the applications that must provide long-lived video streams which consume high resources such as I/O and network bandwidth to a large number of clients. Therefore, a video server must secure the necessary resources for each stream during a long period of time (e.g. 7200 seconds) so that the clients can reproduce (play) the video data without witnessing jitter or starvation in their buffers.
This thesis presents the design and implementation for a video proxy server (VPS) which can provide interactive video on demand. The VPS consists of three main parts. The first part is the Admission Control Module which receives the clients' requests, negotiates the required resources, and decides whether to accept or reject a client based on the available resources. The second part is the Resources Management Module which manages several shared resources such as the CPU, the Memory, the Network and the Disk It consists of four brokers that can reserve the necessary resources based on a predefined policy. The third part is the CB_MDA algorithm which is responsible for regulating the resources assignment and scheduling the video streams. The CB_MDA uses a combination of multicast and unicast channels for transmitting the video data. The multicast streams are initiated to start a video file from the beginning while the unicast channels are used to join the later arrivals to the appropriate multicast stream. In the implementation, the CB_MDA discovers the period of time when the server has plenty of resources an assigns them to appropriate clients in order to create work-ahead video data.
The thesis further goes beyond the design of the VPS and presents a video client architecture that can synchronize with the server and work as a plug-in for producing the video data on different players such as MPEG-Berkely player, Xine.etc.
5
Papanikolaou, Aikaterini. "Server and management system design for a distributed VoD service." Thesis, University College London (University of London), 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342295.
Full text
6
Westin, Georg. "Evaluation of Video-on-Demand Streaming Servers." Thesis, Blekinge Tekniska Högskola, Institutionen för programvaruteknik och datavetenskap, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-2307.
Full textAbstract:
This thesis evaluates and presents streaming server solutions in terms of price and performance with focus on delivering high quality video movies over broadband. The general results that have been found are that Darwin Streaming Server for Linux is recommended for a distributed solution with many nodes in the network where large distribution cost per movie is acceptable, Darwin Streaming Server for Windows is not recommended and Windows Media 9 Series is recommended in distributions where few servers can be used in the streaming network and low cost per delivered object is highly desirable.Rapporten presenterar en utvärdering av streaming server lösningar med avseende på pris och prestanda. Fokus ligger på att utvärdera möjligheterna att streama hög kvalitets video över bredband. De generella resultaten är att Darwin Streaming Server för Linux är rekommenderad för en distribuerad lösning som kräver många noder i nätverket och höga distributionskostnader är acceptabla. Darwin Streaming Server för Windows är inte rekommenderad och Windows Media 9 Series rekommenderas när få streaming servrar kan användas och där låga distributionskostnader är viktiga.
georg.westin@home.se
7
Horyna, Miroslav. "Video telefon." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2015. http://www.nusl.cz/ntk/nusl-221059.
Full textAbstract:
This thesis deals with door video phone on the platform Raspberry Pi. There is described the platform Raspberry Pi, Raspberry Pi Camera module, operating systems for Raspberry Pi and described installing and configuring the software. Next is described the concept and description of programs created for door video phone and design of additional modules.
8
Karpati, Peter. "Designing and scaling proactive, self-organizing video servers a formal and a simulation model." Saarbrücken VDM Verlag Dr. Müller, 2007. http://d-nb.info/98872877X/04.
Full text
9
Regueyra, Philip. "Videokonferenční systém pro distanční výuku." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219286.
Full textAbstract:
The aim of my diploma thesis is to introduce the problematic of today’s videoconference system and to compare the existing solutions. First chapters of my work are dedicated to a description of the theory of the conference system. Furthermore there is described the application Skype and application WebEx. These are the projects that are the nearest to the submission of this work. On the basis of the acquired information, the thesis is dealing with the creation of my own solution of video conference system. In the third chapter there are described all the used technologies needed for the realization of the project. The thesis is then dealing with the creation of own client on the platform Silverlight. This client is working on the components that play the multimedia content and on the service WCF RIA. After the part dedicated to a creation of the client, there are described the settings of services Windows Server 2008, on which the solution is realized. There are described the settings of services of web server, services of multimedia media, settings of SQL server and usage of program Windows Media Encoder. The last part is dedicated to a testing and plotting of the functionality of created video conference system. In the conclusion of the work there are evaluated the results of the work and described possible directions, where the development of the client of video conference could proceed.
10
Al-mufti, Summia, and Rasmus Jönsson. "HTTP/2, Server Push and Branched Video : Evaluation of using HTTP/2 Server Push in Dynamic Adaptive Streaming over HTTP with linear and non-linear prefetching algorithms." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-138726.
Full textAbstract:
The purpose of this thesis is to investigate and test the usage of HTTP/2 in dynamic adaptive video streaming as well as to take a look into how it can be used to benefit prefetching algorithms used with branched video. With a series of experiments the performance gains of using HTTP/2 rather than the older standard HTTP/1.1 has been investigated. The results has shown no significant change to player quality and buffer occupancy when using HTTP/2, though our tests has shown in a slight decrease in overall playback quality when using HTTP/2. When using a linear prefetch of two fragments an average quality improvement of 4.59% has been shown, however, the result is inconclusive due to variations in average quality between different values for how many fragments to prefetch. Average buffer occupancy has shown promise with a maximum increase of 12.58%, when using linear prefetch with three fragments. The values for buffer occupancy gains are conclusive. Two implementations for non-linear prefetching has been made. The first one uses HTTP/2 server push to deliver fragments for prefetching and the second one uses client-side invoked HTTP requests to pull fragments from the server. Using HTTP/2 server push has shown in a decrease of 2.5% in average total load time while using client-side pulling has shown in a decrease of 34% in average total load time.
11
Abdullah, Jan Mirza, and Mahmododfateh Ahsan. "Multi-View Video Transmission over the Internet." Thesis, Linköping University, Department of Electrical Engineering, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-57903.
Full textAbstract:
3D television using multiple views rendering is receiving increasing interest. In this technology a number of video sequences are transmitted simultaneously and provides a larger view of the scene or stereoscopic viewing experience. With two views stereoscopic rendition is possible. Nowadays 3D displays are available that are capable of displaying several views simultaneously and the user is able to see different views by moving his head.
The thesis work aims at implementing a demonstration system with a number of simultaneous views. The system will include two cameras, computers at both the transmitting and receiving end and a multi-view display. Besides setting up the hardware, the main task is to implement software so that the transmission can be done over an IP-network.
This thesis report includes an overview and experiences of similar published systems, the implementation of real time video, its compression, encoding, and transmission over the internet with the help of socket programming and finally the multi-view display in 3D format. This report also describes the design considerations more precisely regarding the video coding and network protocols.
12
Cheng, Xiaolin. "Multiple Description Video Communications in Wireless Ad Hoc Networks." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33590.
Full textAbstract:
As developments in wireless ad hoc networks continue, there is an increasing expectation with regard to supporting content-rich multimedia communications (e.g., video) in such networks, in addition to simple data communications. The recent advances in multiple description (MD) video coding have made it highly suitable for multimedia applications in such networks. In this thesis, we study three important problems regarding multiple description video communications in wireless ad hoc networks. They are multipath routing for MD
video, MD video multicast, and joint routing and server selection for MD video in wireless ad hoc networks. In multipath routing for MD video problem, we follow an applicationcentric
cross-layer approach and formulate an optimal routing problem that minimizes the application layer video distortion. We show that the optimization problem has a highly complex objective function and an exact analytic solution is not obtainable. However, we find that a metaheuristic approach such as Genetic Algorithms (GAs) is eminently effective in addressing this type of complex cross-layer optimization problems. We provide a detailed solution procedure for the GA-based approach, as well as a tight lower bound for video distortion. We use numerical results to compare this approach to several other approaches
and demonstrate its superior performance. In MD video multicast problem, we take the similar application-centric, cross-layer approach as in the multipath routing problem. We propose an MD video multicast scheme where multiple source trees are used. Furthermore, each video description is coded into multiple layers in order to cope with diversity in wireless link bandwidths. Based on this multicast model, we formulate the multicast routing as a combinatorial optimization problem and apply Genetic Algorithm (GA)-based metaheuristic procedure to solove this problem. Performance comparisons with existing approaches show significant gains for a wide range of network operating conditions. In the last problem, we study the important problem of joint routing and server selection for MD video in ad hoc networks. We formulate the task as a combinatorial optimization problem and present tight lower and upper bounds for the achievable distortion. The upper bound also provides a feasible solution to the formulated problem. Our extensive numerical results show that the bounds are very close to each other for all the cases studied, indicating the near-global optimality of the derived upper bounding solution. Moreover, we observe significant gains in video quality achieved by the proposed approach over existing server selection schemes. This justifies the importance of jointly considering routing and server selection for optimal MD video streaming in wireless ad hoc networks.Master of Science
13
Dušek, Martin. "Implementace protokolu SIP." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-218958.
Full textAbstract:
This Master’s thesis deals in detail with the SIP protocol – a method of communication between two entities, various types of transmitted messages and their content. Few SIP libraries are introduced and two of them are used for development of an application for audio/video conference-calls. Compilation of OPAL and PTlib libraries for Windows 7 Professional (64bit) is described, and problems resulting from lack of information provided by authors. New improved “how to build” is presented. At the end, paper focuses on several ways of development of mentioned application.
14
Goularte, Rudinei. "Utilização de metadados no gerenciamento de acesso a servidores de vídeo." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/55/55134/tde-29012001-160200/.
Full textAbstract:
A experiência com autoria de material didático multimídia para propósitos educacionais mostra um grande problema: como prover uma maneira de tratar objetos multimídia de modo que usuários inexperientes (como professores) possam estar aptos a projetar e construir suas próprias apresentações? A criação de tais apresentações envolve fatores como armazenamento, entrega, busca e apresentação de material multimídia (vídeo em especial). Uma infra-estrutura básica que armazene e entregue eficientemente os dados de vídeo é necessária, porém, outro ponto importante é organizar esses dados armazenados no servidor de forma a facilitar seu acesso por parte dos usuários. Neste trabalho, isto é alcançado através do uso de um sistema interativo de recuperação e gerenciamento de informações projetado para facilitar o acesso a itens (ou parte deles) armazenados no servidor. A principal característica de tal sistema é o uso de uma base de metadados contendo os atributos dos vídeos armazenados no servidor. Buscas podem ser feitas por título, assunto, tamanho, autor, conteúdo ou, mais importante no caso de material didático, por cenas ou frames específicos. O sistema foi implementado segundo uma abordagem cliente/servidor utilizando a linguagem de programação JAVA. A comunicação entre clientes e servidores é realizada através do uso do Visibroker 3.0, que é uma ferramenta de programação para Objetos Distribuídos segundo o padrão CORBA. O acesso aos dados a partir da base de metadados é realizado através do uso de um driver PostgreSQL que segue a API JDBC. Para propósitos de avaliação do sistema um player foi construído utilizando a ferramenta Java Media Framework (JMF). Foi realizada uma análise para a verificação do impacto da utilização das tecnologias CORBA e JDBC no sistema. Foi detectado que a utilização da tecnologia JDBC impõe um atraso muito mais significante que a utilização da tecnologia CORBA. Outra conclusão é que a utilização de metadados provê uma melhor interatividade em buscas, permite economia de tempo durante o processo de edição e provê economia de espaço de armazenamento através do compartilhamento de objetos como vídeos, cenas e frames.The experience with authoring multimedia material for educational purposes shows a major problem: how to provide an easy and efficient way to handle multimedia objects in a manner that non-expert users (namely school teachers) can be able to design and build their own presentations? The creation of this presentations involves factors like storage, delivery, search and presentation of multimedia material (video in special). A basic infra-structure that stores and efficiently deliver the video data is needed. However, another important point is the organization of these data stored into the server in a way to facilitate the access to them from the users. In the system wich is the subject of this work, this is achived through the use of an interactive information management and retrieval system designed to facilitate the access to items (or parts of the items) stored in the server. The main characteristic of the system is the use of a metadata base which contains attributes of the videos stored in the server. Searches can be made by title, subject, length, author, content or, most important in the didatic multimedia material case, by a specific scene or frame. The system was built with JAVA programming language in a client/server way. The communication between clients and servers is realized through the use of the Visibroker 3.0, which is a Distributed Objects programming tool according to the CORBA standard. The data access from the metadata base use a PostgreSQL driver which follows the JDBC API. For evaluation purposes a playback tool was built using Java Media Framework (JMF). An analisys was carried out to verify the impact of the utilization of CORBA and JDBC technologies in the system. It was detected that JDBC technology utilization imposes a much more significate delay than the CORBA technology utilization. Another conclusion is that metadata utilization provide better interactivity searches, making the editing process faster and save storage space through the sharing of objects like videos, scenes and frames.
15
Černý, Pavel. "Prednasky.com - systém pro automatické zpracování přednášek." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2015. http://www.nusl.cz/ntk/nusl-264970.
Full textAbstract:
The objective of this thesis is to create system for automated processing of the video lectures. There are two main parts in this thesis. Bash Framework, which is created from several separated atomic tasks. At the beginning we have a simple video prepared for processing. When it is processed, there are added intro part, subtitles and synchronized presentation. Second part of this thesis is a web application. It is designated for playing, editing and creating videos. Further it provides process management of created framework and whole system administration.
16
Křenek, Tomáš. "Audio a video vysílání s využitím real-time protokolu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218188.
Full textAbstract:
This diploma thesis focus on transmiting multimedia over computer network. There are detailed informations about protocols RTP and RTPC in a first part because a transmition over a network is realized by using these protocols. Some basic multimedia terms, FFmpeg codecs and SDL library are described in next chapters. A multimedia player using FFmpeg and SDL is implemented in a second part of thesis. The player is console application and it has basic user interface. The player reproduces video and audio from a given file. RTP communication is described in next chapters of the second part. RTP server and client are implemented there too. They are console aplications and they use data coded by Theora or Vorbis. There are summarized results in a conclusion.
17
Chong, Luis A. Caceres. "DYNAMAC media distribution system /." Online version of thesis, 2007. http://hdl.handle.net/1850/5545.
Full text
18
Kolář, Jakub. "Návrh mobilní aplikace pro správu serveru." Master's thesis, Vysoká škola ekonomická v Praze, 2015. http://www.nusl.cz/ntk/nusl-202096.
Full textAbstract:
Thesis deals with remote servers specifically those for the Minecraft. These servers are divided into groups. The work examines the possibility of remote access to these servers on network protocols level, which are described briefly, and also at the level of the game itself. Describes the game options that can be influenced via remote management. Then analyzes the applications that are intended for this remote access, and identifies problems associated with them. Based on the issues that implied from this analysis, application that solves these problems is designed. The first chapter contains a brief description of the network protocols that can be used to remotely manage servers for the Minecraft and identifies the most appropriate protocol. The next chapter describes the Minecraft, and specifically those of its regions which can be influenced via remote management. The next chapter analyzes the applications that can be used to remotely manage Minecraft servers and based on the problems that this analysis identifies, an application that solves these problems is designed. The designed application is then implemented. The last part contains user documentation of created application.
19
Lidström, Martin, and Ulf Jonsson. "Videosamtal i webbutik." Thesis, Växjö University, School of Mathematics and Systems Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:vxu:diva-438.
Full textAbstract:
I traditionella butiker kan kunden välja att ta kontakt med en försäljare för att få information om produkter eller tjänster. Försäljaren kan tipsa om lösningar efter kundens behov, även visa upp hur produkten fungerar och kunden kan själv välja vilken fråga han eller hon vill ha svar på. Den här mänskliga realtidskontakten kan i många fall vara värdefull och förtroendegivande för kunden. Vi antar att mervärden skapas för kunden när denne kan mötas ansikte mot ansikte och samtala med försäljare i en webbutik. För att se vilka dessa mervärden kunde vara, designade vi en prototyp för videosamtal. Denna implementerades i en fiktiv webbutik, som tillhandhöll kläder. Fem testpersoner fick agera presumtiva kunder och föra videosamtal med en professionell försäljare. Testpersonerna och försäljaren satt i olika rum och videosamtalen fördes via ett lokalt nätverk. Efter varje test genomfördes en kvalitativ intervju med testpersonerna och resultaten visade vilka mervärden som hade skapats. Ett mervärde var den personliga servicen med omedelbar feedback som försäljaren gav, i huvudsak via ljudkanalen. Videosamtalen medförde att kunderna kunde förhandla om priser och leveranstider. Ett annat var att kunder kunde få sina klädmått bedömda, men endast korrekt bedömda i två fall av fem. Ett annat visuellt mervärde var att kunden kunde be försäljaren att visa upp olika kombinationer av klädesplagg för att se hur de passade ihop med varandra. En testperson tyckte ett mervärde var att klädesplaggen kunde ses ur den vinkel som önskades. Ytterligare ett mervärde var att webbutiken upplevdes som trovärdig när försäljaren fanns i den som en fysisk gestalt. Testpersonerna tyckte att videosamtalen gjorde att de fick förtroende för webbutiken.
In retail shops in real life the customer can chose to contact a salesman to get information about products or services. The salesman can recommend solutions depending on the customers needs. The salesman can show the product to the customer and tell how it works. The customer on the other hand can ask questions to the salesman about the product to get the specific information that interests him or her. This human contact in real time can be valuable and confidece inspiring for the customer in many situations. We assume there are surplus values for the customer when he or she will meet face to face with a salesman via a video call in a webshop. To find out which these surplus values could be we designed a prototype for video calls. This was implemented in a fictitious webshop that supplied clothes. Five persons with experience from webbshopping acted customers and had video calls with a professional salesman. The customers and the salesman were in different rooms and could only communicate through a video call. Their computers were connected via a local network. We did qualitative interviews with every customer after each test and the results showed the surplus values that were generated. One surplus value was the personal service with instant feedback that the customer got from the salesman, mainly through the sound channel. The video calls resulted in negotiations about prices and delivery times. Another surplus value was that the salesman estimated the customers sizes in trousers and jackets. He only succeded in two cases of five. Another visual surplus value was that the customer asked the salesman to show articles of clothing in different combinations to see how them fit together. One person thought one surplus value was that he could see an article of clothing from whichever angle he wished. Further surplus value was that the customers experienced the webshop as trustworthy when the salesman was there as a physical human being. The customers thought that the video calls caused that they got confidence in the webshop.
20
Wu, Yuk Ying. "Movie allocation in parallel video servers /." View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?COMP%202002%20WU.
Full textAbstract:
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002.Includes bibliographical references (leaves 69-76). Also available in electronic version. Access restricted to campus users.
21
Shi, Feng. "An architecture for scalable and deterministic video servers." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627397.
Full text
22
He, Jingzhu. "Video file distribution among geo-distributed cloud servers." HKBU Institutional Repository, 2016. https://repository.hkbu.edu.hk/etd_oa/304.
Full textAbstract:
With the emergence of cloud computing, many applications are migrated onto clouds. Video-on-demand (VoD) can be implemented on the cloud platform with geo-distributed cloud servers to serve worldwide users. New videos are distributed to these geo-distributed cloud servers. This distribution should be properly scheduled based on the videos' sizes, videos' popularities and the available network bandwidth, so that the mean completion time is minimized. We formulate this problemas a preemptive scheduling problem, prove that it is NP-hard, and design a heuristic scheduling algorithm to solve it. This algorithm iteratively determines: 1) themost preferred file to be received by the most preferred destination server by pairwise analysis and PageRank, and 2) the most preferred source servers which can transmit this file to the most preferred destination server with appropriate data rates. The simulation results demonstrate that the proposed scheduling algorithm gives much smaller mean completion time than four scheduling algorithms.
23
Pokhrel, Jeevan. "Intelligent quality of experience (QoE) analysis of network served multimedia and web contents." Thesis, Evry, Institut national des télécommunications, 2014. http://www.theses.fr/2014TELE0027/document.
Full textAbstract:
De nos jours, l’expérience de l'utilisateur appelé en anglais « User Experience » est devenue l’un des indicateurs les plus pertinents pour les fournisseurs de services ainsi que pour les opérateurs de télécommunication pour analyser le fonctionnement de bout en bout de leurs systèmes (du terminal client, en passant par le réseaux jusqu’à l’infrastructure des services etc.). De plus, afin d’entretenir leur part de marché et rester compétitif, les différents opérateurs de télécommunication et les fournisseurs de services doivent constamment conserver et accroître le nombre de souscription des clients. Pour répondre à ces exigences, ils doivent disposer de solutions efficaces de monitoring et d’estimation de la qualité d'expérience (QoE) afin d’évaluer la satisfaction de leur clients. Cependant, la QoE est une mesure qui reste subjective et son évaluation est coûteuse et fastidieuse car elle nécessite une forte participation humaine (appelé panel de d’évaluation). Par conséquent, la conception d’un outil qui peut mesurer objectivement cette qualité d'expérience avec une précision raisonnable et en temps réel est devenue un besoin primordial qui constitue un challenge intéressant à résoudre. Comme une première contribution, nous avons analysé l'impact du comportement d’un réseau sur la qualité des services de vidéo à la demande (VOD). Nous avons également proposé un outil d'estimation objective de la QoE qui utilise le système expert basé sur la logique floue pour évaluer la QoE à partir des paramètres de qualité de service de la couche réseau. Dans une deuxième contribution, nous avons analysé l'impact des paramètres QoS de couche MAC sur les services de VoD dans le cadre des réseaux sans fil IEEE 802.11n. Nous avons également proposé un outil d'estimation objective de la QoE qui utilise le réseau aléatoire de neurones pour estimer la QoE dans la perspective de la couche MAC. Pour notre troisième contribution, nous avons analysé l'effet de différents scénarios d'adaptation sur la QoE dans le cadre du streaming adaptatif au débit. Nous avons également développé une plate-Forme Web de test subjectif qui peut être facilement intégré dans une plate-Forme de crowd-Sourcing pour effectuer des tests subjectifs. Finalement, pour notre quatrième contribution, nous avons analysé l'impact des différents paramètres de qualité de service Web sur leur QoE. Nous avons également proposé un algorithme d'apprentissage automatique i.e. un système expert hybride rugueux basé sur la logique floue pour estimer objectivement la QoE des Web servicesToday user experience is becoming a reliable indicator for service providers and telecommunication operators to convey overall end to end system functioning. Moreover, to compete for a prominent market share, different network operators and service providers should retain and increase the customers’ subscription. To fulfil these requirements they require an efficient Quality of Experience (QoE) monitoring and estimation. However, QoE is a subjective metric and its evaluation is expensive and time consuming since it requires human participation. Therefore, there is a need for an objective tool that can measure the QoE objectively with reasonable accuracy in real-Time. As a first contribution, we analyzed the impact of network conditions on Video on Demand (VoD) services. We also proposed an objective QoE estimation tool that uses fuzzy expert system to estimate QoE from network layer QoS parameters. As a second contribution, we analyzed the impact of MAC layer QoS parameters on VoD services over IEEE 802.11n wireless networks. We also proposed an objective QoE estimation tool that uses random neural network to estimate QoE from the MAC layer perspective. As our third contribution, we analyzed the effect of different adaption scenarios on QoE of adaptive bit rate streaming. We also developed a web based subjective test platform that can be easily integrated in a crowdsourcing platform for performing subjective tests. As our fourth contribution, we analyzed the impact of different web QoS parameters on web service QoE. We also proposed a novel machine learning algorithm i.e. fuzzy rough hybrid expert system for estimating web service QoE objectively
24
Marlow, Gregory. "Principles of Digital Animation Video Series." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etsu-oer/2.
Full textAbstract:
The Principles of Digital Animation course provides students with an awareness of animation and other 3D industries, as well as preliminary hands-on experience in animation production. This is a collection of openly licensed videos created by Gregory Marlow for the Principles of Digital Animation course taught during the Fall 2019 semester. For ease of adopting and adapting, the streaming version is embedded for each video and the original video and subtitle files are available to download.https://dc.etsu.edu/etsu-oer/1001/thumbnail.jpg
25
Lukeš, Pavel. "Implementace nových koncových uzlů do firmy a jejich management." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2016. http://www.nusl.cz/ntk/nusl-241594.
Full textAbstract:
This thesis deals with analysis of company’s MBG, spol. s r.o. problems, following with teoretical basis for these problems and in the end, it suggests the solutions. These problems are insufficient monitoring, any of used technology are old and absent of any information security management system. The first part is focused on a teoretical basis for the described problems, the second part will completely analyze all mentioned problems of a company. Final part will contain a solution for every company’s problem, based on theory and analysis with taking care about company’s demand too.
26
Belda, Ortega Román. "Mejora del streaming de vídeo en DASH con codificación de bitrate variable mediante el algoritmo Look Ahead y mecanismos de coordinación para la reproducción, y propuesta de nuevas métricas para la evaluación de la QoE." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/169467.
Full textAbstract:
[ES] Esta tesis presenta diversas propuestas encaminadas a mejorar la transmisión de vídeo a través del estándar DASH (Dynamic Adaptive Streaming over HTTP).
Este trabajo de investigación estudia el protocolo de transmisión DASH y sus características. A la vez, plantea la codificación con calidad constante y bitrate variable como modo de codificación del contenido de vídeo más indicado para la transmisión de contenido bajo demanda mediante el estándar DASH.
Derivado de la propuesta de utilización del modo de codificación de calidad constante, cobra mayor importancia el papel que juegan los algoritmos de adaptación en la experiencia de los usuarios al consumir el contenido multimedia. En este sentido, esta tesis presenta un algoritmo de adaptación denominado Look Ahead el cual, sin modificar el estándar, permite utilizar la información de los tamaños de los segmentos de vídeo incluida en los contenedores multimedia para evitar tomar decisiones de adaptación que desemboquen en paradas no deseadas en la reproducción de contenido multimedia.
Con el objetivo de evaluar las posibles mejoras del algoritmo de adaptación presentado, se proponen tres modelos de evaluación objetiva de la QoE. Los modelos propuestos permiten predecir de forma sencilla la QoE que tendrían los usuarios de forma objetiva, utilizando parámetros conocidos como el bitrate medio, el PSNR (Peak Signal-to-Noise Ratio) y el valor de VMAF (Video Multimethod Assessment Fusion). Todos ellos aplicados a cada segmento.
Finalmente, se estudia el comportamiento de DASH en entornos Wi-Fi con alta densidad de usuarios. En este contexto, se producen un número elevado de paradas en la reproducción por una mala estimación de la tasa de transferencia disponible debida al patrón ON/OFF de descarga de DASH y a la variabilidad del acceso al medio de Wi-Fi. Para paliar esta situación, se propone un servicio de coordinación basado en la tecnología SAND (MPEG's Server and Network Assisted DASH) que proporciona una estimación de la tasa de transferencia basada en la información del estado de los players de los clientes.[CA] Aquesta tesi presenta diverses propostes encaminades a millorar la transmissió de vídeo a través de l'estàndard DASH (Dynamic Adaptive Streaming over HTTP). Aquest treball de recerca estudia el protocol de transmissió DASH i les seves característiques. Alhora, planteja la codificació amb qualitat constant i bitrate variable com a manera de codificació del contingut de vídeo més indicada per a la transmissió de contingut sota demanda mitjançant l'estàndard DASH. Derivat de la proposta d'utilització de la manera de codificació de qualitat constant, cobra major importància el paper que juguen els algorismes d'adaptació en l'experiència dels usuaris en consumir el contingut. En aquest sentit, aquesta tesi presenta un algoritme d'adaptació denominat Look Ahead el qual, sense modificar l'estàndard, permet utilitzar la informació de les grandàries dels segments de vídeo inclosa en els contenidors multimèdia per a evitar prendre decisions d'adaptació que desemboquin en una parada indesitjada en la reproducció de contingut multimèdia. Amb l'objectiu d'avaluar les possibles millores de l'algoritme d'adaptació presentat, es proposen tres models d'avaluació objectiva de la QoE. Els models proposats permeten predir de manera senzilla la QoE que tindrien els usuaris de manera objectiva, utilitzant paràmetres coneguts com el bitrate mitjà, el PSNR (Peak Signal-to-Noise Ratio) i el valor de VMAF (Video Multimethod Assessment Fusion). Tots ells aplicats a cada segment. Finalment, s'estudia el comportament de DASH en entorns Wi-Fi amb alta densitat d'usuaris. En aquest context es produeixen un nombre elevat de parades en la reproducció per una mala estimació de la taxa de transferència disponible deguda al patró ON/OFF de descàrrega de DASH i a la variabilitat de l'accés al mitjà de Wi-Fi. Per a pal·liar aquesta situació, es proposa un servei de coordinació basat en la tecnologia SAND (MPEG's Server and Network Assisted DASH) que proporciona una estimació de la taxa de transferència basada en la informació de l'estat dels players dels clients.
[EN] This thesis presents several proposals aimed at improving video transmission through the DASH (Dynamic Adaptive Streaming over HTTP) standard. This research work studies the DASH transmission protocol and its characteristics. At the same time, this work proposes the use of encoding with constant quality and variable bitrate as the most suitable video content encoding mode for on-demand content transmission through the DASH standard. Based on the proposal to use the constant quality encoding mode, the role played by adaptation algorithms in the user experience when consuming multimedia content becomes more important. In this sense, this thesis presents an adaptation algorithm called Look Ahead which, without modifying the standard, allows the use of the information on the sizes of the video segments included in the multimedia containers to avoid making adaptation decisions that lead to undesirable stalls during the playback of multimedia content. In order to evaluate the improvements of the presented adaptation algorithm, three models of objective QoE evaluation are proposed. These models allow to predict in a simple way the QoE that users would have in an objective way, using well-known parameters such as the average bitrate, the PSNR (Peak Signal-to-Noise Ratio) and the VMAF (Video Multimethod Assessment Fusion). All of them applied to each segment. Finally, the DASH behavior in Wi-Fi environments with high user density is analyzed. In this context, there could be a high number of stalls in the playback because of a bad estimation of the available transfer rate due to the ON/OFF pattern of DASH download and to the variability of the access to the Wi-Fi environment. To relieve this situation, a coordination service based on SAND (MPEG's Server and Network Assisted DASH) is proposed, which provides an estimation of the transfer rate based on the information of the state of the clients' players.
Belda Ortega, R. (2021). Mejora del streaming de vídeo en DASH con codificación de bitrate variable mediante el algoritmo Look Ahead y mecanismos de coordinación para la reproducción, y propuesta de nuevas métricas para la evaluación de la QoE [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/169467
TESIS
27
Abousabea, Emad Mohamed Abd Elrahman. "Optimization algorithms for video service delivery." Thesis, Evry, Institut national des télécommunications, 2012. http://www.theses.fr/2012TELE0030/document.
Full textAbstract:
L'objectif de cette thèse est de fournir des algorithmes d'optimisation pour l'accès aux services vidéo qu’ils soient non-gérés (Internet TV) ou gérés (IPTV). Nous étudions des statistiques récentes concernant les services vidéo non-gérés comme YouTube et nous proposons des techniques d'optimisation appropriées qui pourraient améliorer l'accès aux fichiers vidéos et réduire le coût de cet accès. En outre, l’analyse des coûts joue un rôle important dans les décisions qui concernent la mise en cache des fichiers vidéos et celles liées au choix des périodes temporelles d'hébergement de ces fichiers sur les serveurs. En ce qui concerne les services vidéo gérés appelés IPTV, nous avons mené des expériences sur une architecture ouverte IPTV-collaboration entre différents opérateurs. Ce modèle est analysé selon un critère de coût d’investissement et d'exploitation à l'intérieur de la sphère domestique. En outre, nous avons introduit une solution d’optimisation dynamique de l'arbre « minimum spanning tree » (MST) pour le service IPTV multicast. Lors d’un accès nomade, les arbres statiques pourraient être incapables de fournir le service de manière efficace vu que l'utilisation de la bande passante augmente aux côté des points de streaming (racines de la topologie). Finalement, nous étudions des mesures de sécurité fiables en streaming vidéo basées sur la méthodologie de la chaîne de hachage et nous proposons un nouvel algorithme hybride. Nous effectuons des comparaisons entre les différentes manières utilisées dans la réalisation de la fiabilité des chaînes de hachage basées sur les classifications génériquesThe aim of this thesis is to provide optimization algorithms for accessing video services either in unmanaged or managed ways. We study recent statistics about unmanaged video services like YouTube and propose suitable optimization techniques that could enhance files accessing and reduce their access costs. Moreover, this cost analysis plays an important role in decision making about video files caching and hosting periods on the servers. Under managed video services called IPTV, we conducted experiments for an open-IPTV collaborative architecture between different operators. This model is analyzed in terms of CAPEX and OPEX costs inside the domestic sphere. Moreover, we introduced a dynamic way for optimizing the Minimum Spanning Tree (MST) for multicast IPTV service. In nomadic access, the static trees could be unable to provide the service in an efficient manner as the utilization of bandwidth increases towards the streaming points (roots of topologies). Finally, we study reliable security measures in video streaming based on hash chain methodology and propose a new algorithm. Then, we conduct comparisons between different ways used in achieving reliability of hash chains based on generic classifications
28
Sengupta, Shreeya. "Multidimensional time series classification and its application to video activity recognition." Thesis, Ulster University, 2015. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.673808.
Full textAbstract:
A collection of observations made sequentially through time is known as a time series. The order in which the observations in a time series are recorded is important and is a distinct characteristic of time series. A time series may have only one dimension (unidimensional) or may have multiple dimensions (multidimensional). The research presented in this thesis considers multidimensional time series. Financial stock market, videos, medical (EEG and ECG) and speech data are all examples of multidimensional time series data. Analysis of multidimensional time series data can reveal underlying patterns, the knowledge of which can benefit several time series applications. For example, rules derived by analysing the stock data can be helpful in predicting the behaviour of the stock market and identifying the pattern of the strokes in signatures can aid signature verification. However, time series analysis is often hindered by the presence of variability in the series. Variability refers to the difference in the time series data generated at different points of time. It arises because of the stochasticity of the process generating the time series, non-stationarity of time series, presence of noise in time series and the variable sampling rate with which a time series is sampled. This research studies the effect of non-stationarity and variability on multidimensional time series analysis, with a pat1icular focus on video activity recognition. The research, firstly, studies the effect of non-stationarity, one of the causes of variability, and variability on time series analysis in general. The efficacy of several analysis models was evaluated on various time series problems. Results show that both non-stationarity and variability degrades the performance of the models consequently affecting time series analysis. Then, the research concentrates on video data analysis where space and time variabilities abound. The variability of the video content along the space and time dimension is known as spatial and temporal variability respectively. New methods to handle / minimise the effect of spatial and temporal variabilities are proposed. The proposed methods are then assessed against existing methods which do not handle the spatial and temporal variabilities explicitly. The proposed methods perform better than the existing methods, indicating that better video activity recognition can be achieved by addressing the spatial and temporal variabilities
29
Bost, Xavier. "A storytelling machine ? : automatic video summarization : the case of TV series." Thesis, Avignon, 2016. http://www.theses.fr/2016AVIG0216/document.
Full textAbstract:
Ces dix dernières années, les séries télévisées sont devenues de plus en plus populaires. Par opposition aux séries TV classiques composées d’épisodes autosuffisants d’un point de vue narratif, les séries TV modernes développent des intrigues continues sur des dizaines d’épisodes successifs. Cependant, la continuité narrative des séries TV modernes entre directement en conflit avec les conditions usuelles de visionnage : en raison des technologies modernes de visionnage, les nouvelles saisons des séries TV sont regardées sur de courtes périodes de temps. Par conséquent, les spectateurs sur le point de visionner de nouvelles saisons sont largement désengagés de l’intrigue, à la fois d’un point de vue cognitif et affectif. Une telle situation fournit au résumé de vidéos des scénarios d’utilisation remarquablement réalistes, que nous détaillons dans le Chapitre 1. De plus, le résumé automatique de films, longtemps limité à la génération de bande-annonces à partir de descripteurs de bas niveau, trouve dans les séries TV une occasion inédite d’aborder dans des conditions bien définies ce qu’on appelle le fossé sémantique : le résumé de médias narratifs exige des approches orientées contenu, capables de jeter un pont entre des descripteurs de bas niveau et le niveau humain de compréhension. Nous passons en revue dans le Chapitre 2 les deux principales approches adoptées jusqu’ici pour aborder le problème du résumé automatique de films de fiction. Le Chapitre 3 est consacré aux différentes sous-tâches requises pour construire les représentations intermédiaires sur lesquelles repose notre système de génération de résumés : la Section 3.2 se concentre sur la segmentation de vidéos,tandis que le reste du chapitre est consacré à l’extraction de descripteurs de niveau intermédiaire,soit orientés saillance (échelle des plans, musique de fond), soit en relation avec le contenu (locuteurs). Dans le Chapitre 4, nous utilisons l’analyse des réseaux sociaux comme une manière possible de modéliser l’intrigue des séries TV modernes : la dynamique narrative peut être adéquatement capturée par l’évolution dans le temps du réseau des personnages en interaction. Cependant, nous devons faire face ici au caractère séquentiel de la narration lorsque nous prenons des vues instantanées de l’état des relations entre personnages. Nous montrons que les approches classiques par fenêtrage temporel ne peuvent pas traiter convenablement ce cas, et nous détaillons notre propre méthode pour extraire des réseaux sociaux dynamiques dans les médias narratifs.Le Chapitre 5 est consacré à la génération finale de résumés orientés personnages,capables à la fois de refléter la dynamique de l’intrigue et de ré-engager émotionnellement les spectateurs dans la narration. Nous évaluons notre système en menant à une large échelle et dans des conditions réalistes une enquête auprès d’utilisateursThese past ten years, TV series became increasingly popular. In contrast to classicalTV series consisting of narratively self-sufficient episodes, modern TV seriesdevelop continuous plots over dozens of successive episodes. However, thenarrative continuity of modern TV series directly conflicts with the usual viewing conditions:due to modern viewing technologies, the new seasons of TV series are beingwatched over short periods of time. As a result, viewers are largely disengaged fromthe plot, both cognitively and emotionally, when about to watch new seasons. Sucha situation provides video summarization with remarkably realistic use-case scenarios,that we detail in Chapter 1. Furthermore, automatic movie summarization, longrestricted to trailer generation based on low-level features, finds with TV series a unprecedentedopportunity to address in well-defined conditions the so-called semanticgap: summarization of narrative media requires content-oriented approaches capableto bridge the gap between low-level features and human understanding. We review inChapter 2 the two main approaches adopted so far to address automatic movie summarization.Chapter 3 is dedicated to the various subtasks needed to build the intermediaryrepresentations on which our summarization framework relies: Section 3.2focuses on video segmentation, whereas the rest of Chapter 3 is dedicated to the extractionof different mid-level features, either saliency-oriented (shot size, backgroundmusic), or content-related (speakers). In Chapter 4, we make use of social network analysisas a possible way to model the plot of modern TV series: the narrative dynamicscan be properly captured by the evolution over time of the social network of interactingcharacters. Nonetheless, we have to address here the sequential nature of thenarrative when taking instantaneous views of the state of the relationships between thecharacters. We show that standard time-windowing approaches can not properly handlethis case, and we detail our own method for extracting dynamic social networksfrom narrative media. Chapter 5 is dedicated to the final generation and evaluation ofcharacter-oriented summaries, both able to reflect the plot dynamics and to emotionallyre-engage viewers into the narrative. We evaluate our framework by performing alarge-scale user study in realistic conditions
30
ABOUSABEA, Emad Mohamed Abd Elrahman. "Optimization algorithms for video service delivery." Phd thesis, Institut National des Télécommunications, 2012. http://tel.archives-ouvertes.fr/tel-00762636.
Full textAbstract:
The aim of this thesis is to provide optimization algorithms for accessing video services either in unmanaged or managed ways. We study recent statistics about unmanaged video services like YouTube and propose suitable optimization techniques that could enhance files accessing and reduce their access costs. Moreover, this cost analysis plays an important role in decision making about video files caching and hosting periods on the servers. Under managed video services called IPTV, we conducted experiments for an open-IPTV collaborative architecture between different operators. This model is analyzed in terms of CAPEX and OPEX costs inside the domestic sphere. Moreover, we introduced a dynamic way for optimizing the Minimum Spanning Tree (MST) for multicast IPTV service. In nomadic access, the static trees could be unable to provide the service in an efficient manner as the utilization of bandwidth increases towards the streaming points (roots of topologies). Finally, we study reliable security measures in video streaming based on hash chain methodology and propose a new algorithm. Then, we conduct comparisons between different ways used in achieving reliability of hash chains based on generic classifications
31
Thomas, Brendan Nigel. "Video analysis as a form of feedback to improve sport performance." Thesis, Stellenbosch : Stellenbosch University, 2004. http://hdl.handle.net/10019.1/50225.
Full textAbstract:
Thesis (MScSportSc)--Stellenbosch University, 2004.ENGLISH ABSTRACT: Feedback is critical for motor skill learning. Knowledge of performance (KP) In the form of verbal feedback is the most commonly used type of augmented feedback. Advances in technology have made it possible for coaches to utilise video-supported feedback with athletes with the intention of accelerating the learning process. The use of videotape replay has been an effective aid under some circumstances. Recent commercially available products offer digital analysis that may be even more successful than ordinary video replay in this regard. The purpose of this study was to determine the effectiveness of knowledge of results (KR) and verbal KP with video-support in improving the learning of the tennis serve, when compared to KR with verbal KP only. A total of 18 adults (lOwomen and 8 men) were assessed on their serving technique (6 kinematic variables), accuracy (2 variables) and speed (1 variable). Technique analysis was completed using a commercially available analysis programme. For a short intervention period, one group (n = 10) received KR with verbal feedback only, while the other group (n = 8) received KR plus verbal feedback with video support. The subjects were tested after the intervention to see what changes had occurred with regards to the speed, accuracy and technique of their serves. No significant differences were found for any of the variables, leading to the conclusion that the amount oftime spent in the intervention programme must be extended in order to possibly achieve significant effects on performances.
AFRIKAANSE OPSOMMING: By die aanleer van motoriese vaardighede is terugvoer van kritiese belang. Verbale terugvoering is die mees algemene vorm van kennis oordraging aan die uitvoerder. Verbetering in tegnologie het dit nou moontlik gemaak vir afrigters om videoondersteunde terugvoer met atlete te gebruik, met die doelom die leerproses te versnel. Die gebruik hiervan is in sekere situasies 'n effektiewe hulpmiddel. Kommersiële produkte wat tans beskikbaar is bied die moontlikheid van digitale ontledings, wat dalk meer suksesvol kan wees as slegs die terugspeel van 'n video aan die uitvoerder. Die doel van hierdie studie was om die doeltreffendheid van kennis van resultate (knowledge of results) en verbale terugvoering met video-ondersteuning in die verbetering van die tennis afslaan te meet, en dit dan te vergelyk met kennis van resultate waar net verbale terugvoering verskaf is. 'n Totaal van 18 volwassenes (It) vroue en 8 mans) se afslaantegniek (6 kinematiese verandelikes), akkuraatheid van afslaan (2 verandelikes) en die spoed van die afslaan (1 verandelike) is nagegaan. Tegniekontleding is met die gebruik van 'n komersieël beskikbare analise-program gedoen. Een groep (n = l O) het kennis van resultate en verbale terugvoer gekry vir 'n kort intervensie periode. Die ander groep (n = 8) het kennis van resultate en video-ondersteunde verbale terugvoer, ook vir 'n kort intervensie tydperk ontvang. Die deelnemers is na afloop van die intervensie tydperk getoets om te bepaal watter veranderinge met betrekking tot spoed, akkuraatheid en afslaantegniek plaasgevind het. Geen beduidende verskille is in enige van die verandelikes gevind nie. Dit gee aanleiding tot 'n gevolgtrekking dat die duur van die intervensieprogram verleng moet word om 'n beduidende effek op uitvoering te kry.
32
BONHOMME, ALICE. "Conception d'un systeme de stockage distribue et tolerant aux pannes, pour un serveur de video a la demande." Lyon, École normale supérieure (sciences), 2001. http://www.theses.fr/2001ENSL0192.
Full textAbstract:
L'avancee technologique enregistree ces dernieres annees concernant les reseaux et les technologies de stockage a permis l'emergence d'applications multimedias manipulant de nouveaux types de donnees tels que l'audio ou la video. Ces donnees dynamiques sont semantiquement differentes des donnees statiques (texte, images, etc. ) et se caracterisent par leur volume important et leur contrainte temps-reel. Ainsi, elles imposent aux serveurs de nouveaux besoins en terme de stockage, de techniques d'acces, etc. Les serveurs de donnees classiques ne permettant pas de repondre a ces besoins, de nouvelles approches de stockage et de gestion pour les donnees dynamiques ont ete proposees. Nous nous interessons ici plus particulierement aux aspects de stockage pour des donnees video. Un systeme de stockage pour la video doit etre performant (pour pouvoir servir plusieurs clients), extensible (le rajout d'un element de stockage doit permettre le support de nouveaux clients), economiquement rentable et enfin tolerer les pannes de ses composants afin de ne pas interrompre les flux des clients. L'objectif de cette these est de concevoir un tel systeme, d'etudier son fonctionnement et d'evaluer ses performances. Afin d'avoir un systeme economiquement rentable et extensible, l'architecture materielle choisie est une grappe de pc connectes par le reseau haut debit myrinet. L'architecture logicielle est totalement distribuee sur les noeuds de la grappe. La gestion de la tolerance aux pannes est entierement integree dans la solution et donc transparente a l'utilisateur. Un prototype appele cfs (cluster file system) construit selon cette approche est presente et evalue. L'etude experimentale approfondie permet d'evaluer les divers compromis de conception.
33
Menuez, Paolo Xavier Machado. "The Downward Spiral| Postmodern Consciousness as Buddhist Metaphysics in the Dark Souls Video Game Series." Thesis, Portland State University, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10637267.
Full textAbstract:
This paper is about locating the meaning of a series of games known as the Dark Souls series in relation to contemporary social conditions in Japan. I argue that the game should be thought of as an emblem of the current cultural zeitgeist, in a similar way one might identify something like Jack Kerouac’s The Dharma Bums as an emblem of the counter cultural 60s. I argue that the Dark Souls series expresses in allegorical form an anxiety about living in a time where the meaning of our everyday actions and even society itself has become significantly destabilized. It does this through a fractured approach to story-telling, that is interspersed with Buddhist metaphysics and wrapped up in macabre, gothic aesthetic depicting the last gasping breath of a once great kingdom. This expression of contemporary social anxiety is connected to the discourse of postmodernity in Japan. Through looking at these games as a feedback loop between text, environment and ludic system, I connect the main conceptual motifs that structure the games as a whole with Osawa Masachi’s concept of the post-fictional era and Hiroki Azuma’s definition of the otaku.
34
Billot, Manuel. "Fiabilité comme une extension de la notion de qualité de service : application à un serveur de vidéo à la demande." Université de Rennes 1, 1997. http://www.theses.fr/1997REN10108.
Full textAbstract:
Nous abordons dans ce document le probleme de la fiabilite des applications multimedias. Nous avons limite notre etude a des applications distribuees a flux continu telles que la visio-conference ou la video a la demande. Ces applications transmettant du son ou des images entre deux interlocuteurs distants necessitent la garantie de proprietes telles qu'un debit suffisant entre les interlocuteurs pour assurer le codage des informations ou un delai qui soit suffisamment faible pour etre imperceptible. Ces contraintes necessaires au bon deroulement de l'application sont souvent regroupees sous le terme qos (quality of service). Apres avoir precise la notion de qos dans ces applications multimedias, nous montrons dans ce document que la fiabilite peut etre consideree comme un element de qos. De maniere similaire aux contraintes de temps evoquees precedemment, cette proposition entraine que la fiabilite est negociee entre l'application et le systeme sous-jacent en fonction des besoins de l'application et des capacites du systeme. D'autre part, la fiabilite est garantie durant l'execution de l'application. Ces proprietes sont assurees dans notre proposition a l'aide d'un modele appele ressource fiable. Nous illustrons notre proposition sur l'exemple d'un serveur distribue de video a la demande. Cet exemple nous permet de demontrer que notre proposition peut etre mise en oeuvre dans un cas realiste mais aussi de mettre en avant les avantages de cette methode. La methode offre une grande souplesse dans le choix de la fiabilite ainsi que la transparence des moyens de fiabilisation utilises. D'autre part, nous demontrons sur cet exemple que la souplesse et la transparence obtenues ne le sont pas au depens des performances. En comparant avec l'approche traditionnelle de fiabilisation de ces serveurs fondee sur l'utilisation de raids, nous montrons que notre approche permet d'obtenir une fiabilite equivalente tout en reduisant le surcout en terme de materiel utilise.
35
Yeh, Tiz-Hua, and 葉子華. "Scheduling Strategies of Video Cache in Video Server." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/43004234223662143858.
Full textAbstract:
碩士大同工學院
資訊工程研究所
87
The video cache buffer plays a very important role in the video server. In the past, there were many researches which discuss how to use the video cache buffer space well to reach the real-time playback and multiple user sharing. And the primary technique is to combine the batching and the buffering in video cache buffer. We continue the research and expand the research on interactive services. And we find that the processes of the interactive services-like VCR functions (Jump forward, Jump backward, Fast forward, Rewind, and Pause and resume) in the video server, the current solutions are to require extra video cache buffer space to do the interactive services. And this way wastes video cache buffer space very much. In this thesis, we study the new solution, which includes a management of the video cache buffer to solve this problem. We use the techniques of the batching and the buffering in video cache to be up to the multiple-users environments and satisfy all the interactive requests issued by users quickly. We also find out that the interactive requests are not required extra video cache buffer space in our proposed system and the users become more, the waiting probability, which issued by users, is getting down oppositely. Besides, we also discuss the relation between the video cache buffer and the storage sub-system, and combine the relations with the whole control efficiently to avoid the infinite waiting of users. So, it can come to the reach real interactive requests and satisfies the sprit of the VoD by using our proposed video cache system.
36
Tsai, Chian-Chuan, and 蔡岍權. "Designing Issues of Video Server." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/53068023139807121496.
Full textAbstract:
碩士大同工學院
資訊工程研究所
82
Multimedia is the new trend in computer industry. One of the key multimedia technology is video on demand, which can passive TVs into interactive ones. To make it come true, powerful video servers have to send out continuous video streams requested from thousands of users simultaneously. In this thesis, we present quantitative analysis in designing the hardware and software of video servers. The analysis is based on different scales of video services: low end for tens of clients, middle end for hundreds of users, and high end for thousands of users. For each scale of service, we consider hardware performance, including storage bandwidth and size, bus speed and networking throughput that satisfies the service requirements. In software, we analyze disk scheduling, file management, network management, and synchronization control for providing continuous video and audio streams.
37
Chen, Yu-Pin, and 陳毓斌. "A Fault-Tolerant Video-on-Demand Server." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/17308313334732916478.
Full textAbstract:
碩士國立交通大學
資訊工程學系
86
Fault tolerance requirements for a real-time multimedia server become an important issue in recent years. In a video-on-demand (VOD) environment, disk arrays are often used to support the disk bandwidth requirement. As the number of disks in the video server increases, so does the probability of a disk failure. This can cause serious problems when some disks cannot function normally. Traditionally parity and duplex based approaches provide the capability of recovery but may not guarantee the quality of service. We propose a new scheme of data placement to maintain the quality of service as well as possible in the presence of a single disk failure. In this thesis, we explore the approach of replicating frequently accessed movies to provide high data bandwidth and fault tolerance required in a disk-array-based video server. For those movies that are not so popular, we use parity information to recover the original data. To evaluate the performance of our proposed method, we conduct a series of experiments by simulating the storage and delivery of movies in a VOD system. We compare our method with other approaches in terms of fault tolerance capability after disk failure. Other modules such as admission control and job scheduling algorithm are also studied.
38
Chen, Chie-Hon, and 陳奇宏. "Storage Management of a KTV Video Server." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/37773109068638561657.
Full textAbstract:
碩士國立交通大學
資訊工程學系
84
Due to the reduction of cost in storage devices and rapid progress of mult imedia techniques, it becomes possible to use digital video in a video service system. However, video data are of large amount and require high bandwidth for retrieval. Therefore, to store large amount of video data and to support many concurrent retrieval for clients are the important issues for storage subsyste m of video server. In this thesis, a storage structure of video server is proposed. Upon this structure, a hierarchical storage management system is built which can support several clients for video streams concurrently. Besides, the system can supply large amount of contents for clients to choose under a reasonable cost. There are many methods used to improve performance, guarantee quality of service, an d to reduce the cost of server. These methods include disk scheduling, admissi on control, storage hierarchy and popularity based assignment of contents. Fin ally, by implementing KTV application on the server, the effectiveness and eff iciency of the server can be proved.
39
Roodi, Meysam. "Multi server video streaming using SCTP transport protocol." 2007. http://link.library.utoronto.ca/eir/EIRdetail.cfm?Resources__ID=452848&T=F.
Full text
40
陳祜琦. "A Video Streaming Server with Dynamic Bandwidth Management." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/p4r83r.
Full textAbstract:
碩士國立臺灣師範大學
資訊工程研究所
96
In this thesis, we propose a bandwidth management algorithm and implement a video streaming server with this algorithm. We want the system can achieve two goals as follows: (1) When total used bandwidth of video streaming server is over safety area, video streaming server will manage bandwidth and minimize video quality decadence. (2) When total used bandwidth of video streaming server is under safety area, video streaming server will manage bandwidth and maximize video quality increase. In order to verify this algorithm, we implement a video streaming system simulate program using the algorithm and also implement a positive video streaming system. We will test these two systems in several scenarios and get some measurements. According to those measurements, it can be observed that the algorithm is effective and useful.
41
Jaung, Bo-kai, and 莊博凱. "The Investigation and Implementation of H.264 Video Server." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/46222103440087961747.
Full textAbstract:
碩士義守大學
資訊工程學系碩士班
94
The development of image science and technology has played a very important part in the industry. The need of high quality video are increasing, so there are many technique proposed. The latest video compression standard is H.264. It is the next-generation video compression technology in the MPEG-4 standard, also known as MPEG-4 Part 10. H.264 can match the best possible MPEG-2 quality at up to half the data rate. In addition the development of network are very complete. People rely on network communication more and more. We not only send the message with the form of word but also transmit the multimedia data like image and video. We combined H.264 video compression standard with network , and implemented the H.264 video server . The system is designed on linux operation system with TCP/IP network protocol . It uses a CCD camera to capture the real time image . Then it does two kind of processing . One is image processing , another is video processing .People can connect to the server and get the real time image in the JPEG form or video in the H.264 compressed form by browser.
42
Juang, Yih-Ruey, and 莊益瑞. "The architecture design of video server and admission control." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/07212292594363768259.
Full textAbstract:
碩士國立交通大學
資訊工程研究所
83
In video on demand (VOD), videos are stored on a video server in order to provide a number of customers to be able to view movies at homes simultaneously from a server, and the real-time services like the VCR functions. The requirements of designing a video server for VOD are the high throughput of retrieval system and efficient management of network bandwidth. We propose an architecture of video server Diverging Video Server (DVS), which applies the hierarchical management mechanism to gain the service management. The file system has been isolated from operating system, and diverged to an integral and independent system, so that it can simplify the overhead of file management in operating system. The techniques of parallel processing and pipe-lining are used to advance the system throughput and performance. Video frames can be transferred directly from disk processors to clients. To ensure this constrain, we formulate an admission control algorithm to examine each new client's request to coincide this requirement. A prototype of the DVS has been built. By observing the evaluation result, the proposed architecture of video server can serve the numbers of clients simultaneously more than the other PC-based video server.
43
Najafian, Razavi Maryam. "Performance issues in an interactive video-on-demand server." Thesis, 2000. http://hdl.handle.net/2429/11417.
Full textAbstract:
This research project is an experimental investigation of resource management techniques
that can improve the performance of Interactive Video-On-Demand (IVOD)
servers. Examples of IVOD can be found in digital libraries, hyper-media, education,
entertainment and telemarketing applications. Interactive video programs have some
particular characteristics which need to be considered when designing an IVOD server.
They consist of a series of short video segments which are created by on-line user
interactions and need to be presented to the user in a particular order. The IVOD
server must thus try to keep the latency before start-up and between video segments
to minimum. Furthermore, user arrivals and departures are frequent in most of the
IVOD applications, which causes the server to be in the transient state most of the
time. Thus, The adverse effect of frequent transients on the performance of the server
must also be addressed.
In this research, we identify IVOD performance issues and propose several resource
management strategies to improve the performance of our IVOD server in
various aspects. An IVOD server is designed and implemented to aim evaluating the
suggested techniques.
44
Cheng-Fa, Tsai, and 蔡振發. "JPEG2000-Base Client-Server Video surveillance with Encryption Transmission." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/46617892534469239489.
Full textAbstract:
碩士元智大學
電機工程學系
91
In this thesis, a video surveillance system is studied and implemented client-server communication. The surveillance system includes controllers of digital input (DI) and digital output (DO) for sensor alarm-trigger if the captured images yield some pre-programmed events. To demonstrate applications of the surveillance system, Visual C++ in a Windows environment is employed to realize the whole client-server surveillance system.
45
Chiang, YuYung, and 蔣永裕. "A Practical Video-On-Demand Server Design and Implementation." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/31327146445158170420.
Full text
46
Hou, Yu-Zhan, and 侯玉展. "An Effective Scheduling Policy in Distributed Video Server Environment." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/44208911213208893259.
Full textAbstract:
碩士國立交通大學
資訊工程系
87
Due to the advances in computer and multimedia techniques, the applications of video-on-demand are visible and influence people's life worldwide. However, with the growth of service demand, the single-server architecture is limited by its scalability and server-level fault-tolerance. Recently, several multi-server architectures are proposed to alleviate such problems. In this thesis, we will propose a scalable architecture for video server management system. Our architecture employs not only distributed storage servers but also distributed subscriber management. Wide striping technique is a cost-effective data placement in multi-server architecture. However, the unpredictable access skew from users results in performance degradation. Therefore we design a new scheduling policy to fully utilize the potential bandwidth of wide striping by controlling the startup time of each request. With different modes of our policy, we can benefit from minimum delay or load balance. According to our simulation results, our policy efficiently alleviates load imbalance and thus improves system performance. The detailed information about design principles and performance evaluations will be described in the literature.
47
Lin, Da-Chung, and 林大中. "Flow Control for Video Stream on A VoD Server." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/97080420838113078594.
Full textAbstract:
碩士國立中正大學
資訊工程學系
84
In this thesis, we'll discuss how a VoD server to control the total flow rate ofvideo streams by dynamic changing the QoS level of each user to make the interactive with the other elements of a VoD system possible. At first, we'll show why we choose the CBR model to transmit the MPEG stream from VoD server to users. And we'll explain how can a VBR consuming user avoid starvation under the CBR transmission model. Second, we introduce dynamic QoS level changing to make a VoD server has the ability to control the total flow rate of video streams. We also introduce two disk placement strategies to support dynamic QoS level changing. At last, we'll examine some characteristics of our method under these two disk placement strategies by simulation with a real video data.
48
Wu, Chi-Fon, and 吳奇峰. "A Cost-Effective Video-On-Demand Server Supporting VCR Operations." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/13840786706004693165.
Full textAbstract:
碩士國立交通大學
資訊工程學系
85
In video-on-demand (VOD) services, the video server plays an important role. The design of a good video server should not only consider managing the users' requests quickly, but also take the cost into consideration. This thesis describes a cost- effective solution to the video-on-demand server that not only manages users' requests quickly, but also supports VCR operations such as play, fast-forward, and rewind. Basically, we present a video placement scheme that partitions videos according to MPEG encoding techniques to provide efficient support for fast-forward operations in video servers. In addition to the placement scheme taking MPEG encoding into consideration, we also present a simple real-time scheduling scheme that makes the playback of clients starvation-free and provides better quality of service (QOS). With this scheduling scheme, we also present an admission control policy that can thoroughly handle all system resources to prevent the interference among streams. By the integration of these schemes, we can obtain a video server that can support VCR operations efficiently. A cost model of the proposed video-on-demand server was also established in this thesis. By analysis of this cost model, we will get the cost function of the server and the parameters that make video server cost-effective. We do some simulations to demonstrate the performance of proposed schemes and do some comparisons between the performance of our proposed schemes and that of other schemes to show that our proposed schemes are cost-effective.
49
Liao, Tzung-Wen, and 廖宗文. "A Study on Video-on-Demand Server for e-Learning." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87833468408923196846.
Full textAbstract:
碩士世新大學
資訊管理學研究所(含碩專班)
98
As the Internet developed, how to make video-on-demand(VOD) service without interruption to become an important topic. This paper purpose to design a fault-tolerant ability of clustering server, and to balance the loading of each MP4 VOD servers without down-time limitation, when a user has the same video needs, it can play video directly through the cache server will no longer need to send through the MP4 VOD server, which can save the bandwidth of the inquiries servers without going through the Streaming Proxy as the traditional way and cut down the budget of general maintenance. In this paper, respectively, aim to load-balancing servers, and MP4 VOD server to introduce appropriate mechanisms for fault-tolerant, in this mechanism, the "redundant of load-balancing Server", when the load-balancing servers can not service, start redundant of load-balancing servers and the service will failover to redundant of load-balancing servers, to achieve the on-demand video services are not interrupted. In addition, the thesis for the MP4 VOD servers, use sharing-disk to reduce the respective costs of the maintenance cost of the media, and through the video popularity analysis of streaming proxy server, to avoid the wasteful use of space, full use of disk space, and the levels in accordance with popular video, different grades of film placed in different levels above the disk.
50
Chang, Chih-Wei, and 張智偉. "A Hot Video on Demand Server Based on Fast Broadcast." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/87371522977374120963.
Full textAbstract:
碩士國立中央大學
資訊工程研究所
88
Using multiplae channels to broadcast a hot video can reduce the viewer''s waiting time to approach video-on-demand service. For a 120-minutes movie, conventional broadcasting schemes can support the movie every 30 minutes with 4 video channels. Suppose the set-top box at client end can buffer porions of the playing video on disk. For a given bandwidth, fast broadcasting schemes can provide users with shorter waiting time as compared with conventional broadcasting schemes. The average waiting time is 4 minutes even the longest waiting time is 8minutes. However fast broadcast has many problems in implementing, such as the movie must be divided into many segments, the synchronous problem of multiple video channels and the delay problem of receiving each segment in the client. In this paper, we present a hot video-on-demand server based on fast broadcast schemes and solve the problems in implementing the system.