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Design and analysis of RTP circuit breaker for multimedia applicationsFough, Nazila January 2015 (has links)
Live network multimedia applications (e.g., video conferencing, TV on demand) have been very popular in recent years and are expected to dominate Internet traffic in the near future. With multimedia and Internet-enabled devices being ubiquitous, mechanisms that ensure multimedia flows do not congest the Internet are crucial components of multimedia systems that are embraced rather than opposed by network service providers. The emergence of browser-based multimedia conferencing applications using the WebRTC protocol, an open source project aiming at Real-Time Communication (RTC) with Web, and wide deployment of these applications are expected to increase the traffic of interactive real-time multimedia on the Internet. RTP Media Congestion Avoidance Technique (RMCAT) may be applied to WebRTC, but this is a long-term process and WebRTC deployments will occur before RMCAT is completed. New methods and quick solutions are therefore required to protect the network from uncontrolled media flows until deployment of effective congestion control can be guaranteed. The RTP Protocol Circuit Breaker (RTP-CB) has been proposed in March 2012 within the Internet Engineering Task Force (IETF). Rather than providing congestion control, the RTP-CB is designed only to protect the network by terminating RTP/UDP flows that cause excessive congestion. While the deployment of congestion control for RTP/UDP flow remains an open issue, design a RTP-CB as a quick solution for protecting the current internet is the main focus of this work. In this work by analysing the UDP traffic over a limited path, a RTP-CB algorithm is designed. Then a packet sniffer's code (C routine) is written to sniff and analyse all RTP/UDP, TCP, RTCP SR, and RTCP RR traffic. Based on the designed algorithm the above code was developed further to work as a RTP-CB. This RTP-CB can be deployed on receiver or sender. After deployment of RTP-CB for RTP/UDP flows in a controlled network, its performance in a range of scenarios with using only its congestion rule has been evaluated. The evaluation showed some short coming in performance of RTP-CB in some certain condition when RTP-CB used only congestion rule. The performance of the RTP-CB is evaluated from two perspectives: First, the thesis considered network performance metrics, such as the frequency at which a RTP circuit breaker triggered. Then, it considered the experience of multimedia users, accounting for all outcomes to all users: those congesting the network (where the flow is terminated), those that did not (and are rewarded by reduced congestion) as well as flows that, without severely congesting the network, obtained little quality from a multimedia session and consumed network resources to no avail. Building on the knowledge gathered in these experiments, some extensions (Media Usability Rule) to the RTP-CB rules is proposed and evaluated. This work demonstrates this evaluation by streaming video flows over IP networks using a dedicated test-bed and proposed RTP-CB. These experiments assess the effect of network conditions (packet loss, jitter and network capacity constraint) on the transmission of different types of video stream with and without the proposed RTP-CB Media usability rule. The experiments prove that RTP-CB implementing the congestion rule alone can offer adequate protection to a network, but it does not perform well in some conditions, for example, when the bottleneck buffer size is small. Experiments confirm that the proposed (computationally inexpensive) modifications to the RTP-CB rules improve the RTP-CB performance. The results of these experiments and media usability rule were introduced in IETF RTP-CB draft version 07 of October 27, 2014 and later versions acknowledged contributions by the author of this thesis.
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Real-time scheduling for multimedia services using network delay estimationGibbon, John F. January 1994 (has links)
Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / A multimedia system combines audio, video, graphics, and text into one presentation. Each of these multimedia data types has distinct temporal characteristics. For example video has a specific number of frames that must be displayed per second. There are also temporal relationships that exist between the media. In a movie application, the audio and video streams must be synchronized to achieve a lip syncing effect.
In our system, we manage these temporal requirements through the scheduling of the communication channel; multimedia data is retrieved across the network at the appropriate time so that temporal presentation requirements are met. This real-time scheduling forms a basis for the limited a priori (LAP) scheduler. The scheduler assumes that it knows enough about the system a priori to schedule the next period or limited portion of the presentation. By considering only one period at a time, the scheduler can adapt to dynamic user input or changing communication channel characteristics.
A network delay model and retrieval delay estimation are used by the LAP scheduler when scheduling objects so that they arrive before their playout deadlines. This modeling and estimation also allow the LAP scheduler to decide when there are changes in the communication channel performance that require adjustments to the retrieval schedule. Furthermore, they enable the LAP scheduler to lower the resource requirements of a multimedia presentation when there is less than sufficient network bandwidth or buffer space for normal playout.
The characteristics of the LAP scheduler are first described by analyzing the delay estimation techniques. Properties of the LAP scheduler are further investigated by using performance results from an FDDI network simulation and from an implementation of the LAP scheduler between two Unix workstations interconnected by an Ethernet network. The LAP scheduler wss found to satisfy the proposed objectives for multimedia data retrieval. However, its performance is hindered by the difficulty in predicting network traffic patterns, the normal approximations in the estimation process, and the lack of scheduling for resources other than the communication channel. / 2031-01-01
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The value of teaching history with technology -- a professor's evolutionAthanasopoulos, Evangelos January 2004 (has links)
Thesis (Ed.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This study examined the added value technology in the form of computer-based resources brought to the teaching of history of an experienced, tenured university history professor. This added value was measured by following the evolution of this history professor's adoption of computer-based resources in teaching. During his evolution the use of technology enhanced Dr. K. 's ability to deliver, explain and deepen the meaning of complicated historical lessons.
From summer 2000 to summer 2003 the researcher helped design, develop and create computer-based resources for two history classes at a large northeastern U.S. urban university taught by this fulltime history professor. The researcher also oversaw the implementation, which involved the layering of those multimedia resources.
In 2001, some of the computer-based resources developed for these classes were also partially implemented at a nearby urban high school. Overall the lectures were all put into Microsoft Power Point slides. They included audio clips (WAV) and video clips (AVI, WMV). Some slides also included animations that were created in Macromedia Flash. Other animations were created within Microsoft Power Point to help understanding of elaborate dynamic processes. / 2031-01-01
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MET4MORFOSESUnknown Date (has links)
MET4MORFOSES is an interactive multimedia project marrying ancient mythic
narrative, tabloid celebrity worship, bombardment of consumerist driven
advertising, social media, high technology, and futuristic forms of communication
with speculative science fiction. / Includes bibliography. / Thesis (M.F.A.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
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Like a Rolling Stone: Moving Toward Methodologies for Analysis of Multimodal Musical PerformanceUnknown Date (has links)
As a means for understanding a wide range of multimodal phenomena, multimodal analysis poses methodological challenges for the novice
researcher intent on investigating multimodal communication, especially communication that involves multimodal musical performance (MMP), an
understudied communicative act. As a response to these challenges, this project examines three approaches to multimodal analysis identified
by Carey Jewitt in The Routledge Handbook of Multimodal Analysis as central to studying multimodality writ large: social-semiotic multimodal
analysis (SSMA), multimodal discourse analysis (MDA), and multimodal interactional analysis (MIA). However, while these approaches each
provide a theory and key concepts for analysis, they lack a practicable methodology—necessary for the novice research—and, thus, provide no
concrete way to pursue multimodal analysis or to assess the strengths and deficits of a particular approach when applied to the analysis of
MMPs. In this project, I conduct a critical analysis that includes a theoretical and pragmatic examination of these approaches to multimodal
analysis and assess them for strengths and deficits in terms of a particular MMP because such a performance is an important and
under-explored variety of multimodal text. Thus, this project asks three questions of each approach and its methods: 1) What are the
strengths of each approach to multimodal analysis of musical performance as multimodal communication? 2) What are the deficits of each
approach to multimodal analysis of musical performance as multimodal communication? 3) And, finally, given the strengths and deficits of
competing approaches to multimodal analysis of musical performance as multimodal communication, what do we need moving forward in order to
fully, robustly, and capaciously analyze and understand musical performance as multimodal communication? I respond to these questions by
devising a synthesized, practicable methodology for each approach, one derived from the work in key chapters in The Routledge Handbook
identified by Jewitt as employing a specific approach. I apply each of these methodologies to a single musical performance: video footage
from Bob Dylan’s July 25, 1965 performance at the Newport Folk Festival—which is often seen as a pivotal moment in popular music
history—collected on the 2011 blu-ray release of Murray Lerner’s concert film The Other Side of the Mirror: Bob Dylan Live At Newport Folk
Festival 1963-1965. I assess the results of my application of each methodology and its methods to determine the strengths and deficits of
each approach for analyzing MMPs. Finally, I offer two options to bolster strengths and address deficits of these three approaches to the
multimodal analysis of MMPs, one crafted from combining approaches, and one crafted from a new perspective—that of sonic imaginations
(Sterne)—thus informing methodology with attention to the sonic aspects of MMPs. This dissertation offers three key results important for the
novice researcher. First, it provides a practicable methodology for each approach, a necessary step in the process of assessing an approach's
strengths and deficits. Second, it offers the novice researcher insight into each methodology’s potential. For instance, analyses indicated
that SSMA possesses, among its five strengths, a focus on the sign-maker, while at the same time, it possesses, among its three deficits, no
mechanism through which to consider the multiple sign-makers involved in an MMP. Similarly, MDA possesses, among its six strengths, a focus
on the multimodal phenomenon, while at the same time, it possesses, among its four deficits, a lack of a systematic means for delineating
levels of discourse. And, MDA possesses, among its five strengths, a focus on interaction between social actors involved in an MMP, while at
the same time, it possesses, among its five deficits, a requirement for a considerable amount of guesswork on the part of the researcher.
Third, while demonstrating that no approach to multimodal analysis offers a “best” methodology for the analysis of MMPs, this dissertation
offers two directions for methodological inspiration. It concludes that, through a deliberate courting of emotion by tapping into elements of
music criticism and through a deliberate courting of messiness by embracing the union of emotion and analysis, methodologies for analysis can
be crafted that align with the demands of MMPs. / A Dissertation submitted to the Department of English in partial fulfillment of the requirements for the
degree of Doctor of Philosophy. / Fall Semester 2017. / October 25, 2017. / Composition, Methodologies, Multimodal Analysis, Music, Musical Performance, Sound Studies / Includes bibliographical references. / Kristie Fleckenstein, Professor Directing Dissertation; Davis Houck, University Representative; Kathleen
Blake Yancey, Committee Member; Michael Neal, Committee Member.
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Design and implementation of high speed multimedia network.January 1994 (has links)
by Yeung Chung Toa. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 63-[65]). / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Bandwidth required by multimedia applications --- p.1 / Chapter 1.2 --- Real-time requirement --- p.2 / Chapter 1.3 --- Multicasting --- p.2 / Chapter 1.4 --- Other networks --- p.3 / Chapter 1.5 --- Overview of CUM LAUDE NET --- p.5 / Chapter 1.5.1 --- Protocols --- p.7 / Chapter 1.5.2 --- Network Services --- p.8 / Chapter 1.6 --- Scope of the Thesis --- p.9 / Chapter 2 --- Network Architecture --- p.11 / Chapter 2.1 --- CUM LAUDE NET Architectural Overview --- p.11 / Chapter 2.2 --- Level One Network Architecture --- p.12 / Chapter 2.3 --- Level-One Router --- p.14 / Chapter 2.3.1 --- packet forwarding --- p.14 / Chapter 2.3.2 --- packet insertion --- p.15 / Chapter 2.3.3 --- packet removal --- p.15 / Chapter 2.3.4 --- fault protection --- p.15 / Chapter 2.4 --- Hub --- p.16 / Chapter 2.5 --- Host & Network Interface Card --- p.17 / Chapter 3 --- Protocol --- p.19 / Chapter 3.1 --- Design Overview --- p.19 / Chapter 3.2 --- Layering --- p.20 / Chapter 3.3 --- "Segment, Datagram, and Packet Format" --- p.21 / Chapter 3.3.1 --- IP/VCI field --- p.23 / Chapter 3.4 --- Data Link --- p.23 / Chapter 3.4.1 --- byte format and data link synchronization --- p.23 / Chapter 3.4.2 --- access control byte --- p.24 / Chapter 3.4.3 --- packet/frame boundary --- p.26 / Chapter 3.5 --- Fast Packet Routing Protocol --- p.26 / Chapter 3.5.1 --- Level-2/Level-l Bridge/Router --- p.27 / Chapter 3.5.2 --- Level-1 Hub --- p.29 / Chapter 3.5.3 --- Local Host NIC --- p.29 / Chapter 3.6 --- Media Access Control Protocol I : ACTA --- p.30 / Chapter 3.7 --- Media Access Control Protocol II: Hub Polling --- p.34 / Chapter 3.8 --- Protocol Implementation on CUM LAUDE NET --- p.36 / Chapter 4 --- Hardware Implementation & Performance of Routers and NIC --- p.40 / Chapter 4.1 --- Functionality of Router --- p.40 / Chapter 4.2 --- Important Components Used in the Router Design --- p.43 / Chapter 4.2.1 --- TAXI Transmitter and Receiver --- p.43 / Chapter 4.2.2 --- First-In-First-Out Memory (FIFO) --- p.44 / Chapter 4.3 --- Design of Router --- p.45 / Chapter 4.3.1 --- Version 1 --- p.45 / Chapter 4.3.2 --- Version 2 --- p.47 / Chapter 4.3.3 --- Version 3 --- p.50 / Chapter 4.4 --- Lessons Learned from the High Speed Router Design --- p.57 / Chapter 5 --- Conclusion --- p.61 / Bibliography --- p.63
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Interactive multimedia design features : their derivation, application and assessment in electronic shoppingNemetz, Fabio January 2013 (has links)
The aim of this thesis is to investigate interactive multimedia design: from the analysis of problems with multimedia systems to the subsequent derivation of design features and their assessment. It concentrates on the application of interactive multimedia from a user-centred perspective to rational, choice-based decision making in electronic-shopping, and specifically as a solution to the difficulty consumers have in judging product quality. The popularity and widespread use of interactive technologies, especially the Internet, the complexities of multimedia design, and the importance of electronic-shopping make the need for this investigation timely. The research approach consisted of the following: the derivation of design features through analysis of designs, interviews with designers and review of relevant literature; application of design features through an understanding of problems with electronic-shopping and development of a prototype shopping environment; and assessment of the features through empirical work. The thesis produces three key findings. First, a set of six design features to support multimedia design: naturalness/realness, media allocation and combination, redundancy, significant contribution of the media, exploration, and quality of information representation. Second, a better understanding of multimedia design decision-making. And third, the application of interactive multimedia product experience to improve online consumer behaviour. The research makes contributions to the areas of Human-Computer Interaction and Electronic Commerce, and offers practical recommendations to designers of interactive multimedia, especially when part of their design problem involves support for users’ interactions with representations of choice alternatives.
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Access control in wireless multimedia systems. / CUHK electronic theses & dissertations collectionJanuary 1998 (has links)
by Sung Chi Wan. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 150-[157]). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.
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Data-Driven Sourcing: How Journalists Use Digital Search Tools to Decide What's NewsFink, Katherine January 2014 (has links)
This dissertation examines the efforts of journalists to expand their pool of potential sources beyond a group of people often called "the usual suspects." This group consists of public officials, business leaders, experts, spokespeople, and other people who are in the news often. Using interviews, participant observation, a survey, and online ethnography, this research investigates how a growing skepticism of the usual suspects and increasingly powerful technology have led to innovations in the source search process.
Some journalists have seen potential in digital search tools, including databases and social media, for finding sources that had once been too difficult or time-consuming to find. Journalists themselves have created two source-finding initiatives: a database called the Public Insight Network, and Storyful, which calls itself the "world's first social news agency." Storyful journalists specialize in finding and verifying social media content from the scenes of breaking news events. Journalists have also used other tools created by public relations professionals and technologists.
How did the availability of these tools change the reporting process? It varied by tool, and by journalist. Although the tools were designed to do similar things, journalists used them in different ways. This dissertation examines how journalists used these tools in three stages of the reporting process: finding sources, verifying sources, and managing sources. Ultimately, most journalists used these tools not to find new sources, but to follow and research sources they had already identified by name or location. Few journalists had discovered new sources and story ideas with the help of digital search tools. So while these tools opened new possibilities for finding sources, journalists were still more likely to cover some people and topics over others.
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Factors Affecting the Implementation And Use of Technology in Teaching Biology Courses in Florida's Community CollegesMillen, James W. January 2003 (has links)
Students are constantly immersed in Hollywood glitz, MTV music videos and fastpaced television commercials. For "better or for worse" the movement to make communication a multimedia presentation is upon us. Educational technology -multimedia/Internet - is playing an increasingly important role as a teaching and learning supplement in modern classrooms and has been suggested as an avenue to improve science education. Potential benefits of the Internet, CD-ROMS, Videodiscs, WebCT, course web sites and other computer-based resources include increased communication among students and between instructor and students. Recently, although not a new idea for some, it has been demonstrated that for a significant number of students, learning occurs more readily if the material is presented visually as compared to verbally. Visual presentation is what multimedia is all about. Biology in particular seems to benefit from the application of technology in the classroom since rapid advances in the field make it nearly impossible for textbooks to remain current. Many biology instructors are seeking to take advantage of these benefits by using technology as an increasingly integral part of the teaching experience. This research involves an investigation into how multimedia and the Internet are or are not being used in the teaching of biology courses at the community college level in the State of Florida. A questionnaire was developed to elicit biology faculty perceptions of factors that encourage and those that inhibit their use of the Internet and multimedia in the classroom and in the laboratory. / The Educational Technology Survey was designed for ease of response in order to encourage a high return, and respondents answered the survey via the Internet. The collected data were analyzed by using distributions of frequencies and percentages. Perhaps the most outstanding feature noticeable as a result of this research is that instructor interest was the number one factor responsible for instructors using the Internet or any other form of multimedia. Without the resources, time, faculty development, and technical support, teachers are less likely to use technology in their laboratory and classroom presentations. Educational technology offers exciting possibilities to advance and change teaching, and this research points out some of the factors affecting the implementation of such technology. The study concludes with recommendations for faculty as well as administrators in their efforts to implement technology into the curriculum. Also included are suggestions for further research.
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