126 research outputs found

    On combining temporal scaling and quality scaling for streaming MPEG

    Full text link
    Temporal Scaling and Quality Scaling are both widely-used techniques to reduce the bitrate of streaming video. How-ever, combinations and comparisons of Temporal and Qual-ity Scaling have not been systematically studied. This re-search extends previous work to provide a model for combin-ing Temporal and Quality Scaling, and uses an optimization algorithm to provide a systematic analysis of their combina-tion over a range of network conditions and video content. Analytic experiments show: 1) Quality Scaling typically per-forms better than Temporal Scaling, with performance dif-ferences correlated with the motion characteristics of the video. In fact, when the network capacity is moderate and the loss rate is low, Quality Scaling performs nearly as well as the optimal combination of Quality and Temporal Scal-ing; 2) when the network capacity is low and the packet loss rate is high, Quality Scaling alone is ineffective, but a combination of Quality and Temporal Scaling can provide reasonable video quality; 3) adjusting the amount of For-ward Error Correction (FEC) provides significantly better performance than video streaming without FEC or video streaming with a fixed amount of FEC. 1

    Measuring the Annoyance in Streaming Media Caused by Buffers and Interrupts

    Get PDF
    With the increasing demand for streaming media, it is important to study the effects of quality defects in a video. We concentrated on how buffers and interrupts can impact a user\u27s quality of experience by measuring how a user becomes annoyed with their presence. We determined annoyance by having the user watch a series of videos with different buffer times or interrupt count, asking for the perceived annoyance afterward. The results from 37 users show a polynomial relationship between buffer time and annoyance and a logarithmic relationship between interrupt count and annoyance. These results can be used by streaming services to understand how buffers and interrupts affect users, which can help find a better balance that minimizes annoyance

    Treatment-Based Classi?cation in Residential Wireless Access Points

    Get PDF
    IEEE 802.11 wireless access points (APs) act as the central communication hub inside homes, connecting all networked devices to the Internet. Home users run a variety of network applications with diverse Quality-of-Service requirements (QoS) through their APs. However, wireless APs are often the bottleneck in residential networks as broadband connection speeds keep increasing. Because of the lack of QoS support and complicated configuration procedures in most off-the-shelf APs, users can experience QoS degradation with their wireless networks, especially when multiple applications are running concurrently. This dissertation presents CATNAP, Classification And Treatment iN an AP , to provide better QoS support for various applications over residential wireless networks, especially timely delivery for real-time applications and high throughput for download-based applications. CATNAP consists of three major components: supporting functions, classifiers, and treatment modules. The supporting functions collect necessary flow level statistics and feed it into the CATNAP classifiers. Then, the CATNAP classifiers categorize flows along three-dimensions: response-based/non-response-based, interactive/non-interactive, and greedy/non-greedy. Each CATNAP traffic category can be directly mapped to one of the following treatments: push/delay, limited advertised window size/drop, and reserve bandwidth. Based on the classification results, the CATNAP treatment module automatically applies the treatment policy to provide better QoS support. CATNAP is implemented with the NS network simulator, and evaluated against DropTail and Strict Priority Queue (SPQ) under various network and traffic conditions. In most simulation cases, CATNAP provides better QoS supports than DropTail: it lowers queuing delay for multimedia applications such as VoIP, games and video, fairly treats FTP flows with various round trip times, and is even functional when misbehaving UDP traffic is present. Unlike current QoS methods, CATNAP is a plug-and-play solution, automatically classifying and treating flows without any user configuration, or any modification to end hosts or applications

    Capstone Depleted Uranium Aerosols: Generation and Characterization

    Full text link

    Ecocinema Theory and Practice 2

    Get PDF
    This second volume builds on the initial groundwork laid by Ecocinema Theory and Practice by examining the ways in which ecocritical cinema studies have matured and proliferated over the last decade, opening whole new areas of study and research. Featuring fourteen new essays organized into three sections around the themes of cinematic materialities, discourses, and communities, the volume explores a variety of topics within ecocinema studies from examining specific national and indigenous film contexts to discussing ecojustice, environmental production studies, film festivals, and political ecology. The breadth of the contributions exemplifies how ecocinema scholars worldwide have sought to overcome the historical legacy of binary thinking and intellectual norms and are working to champion new ecocritical, intersectional, decolonial, queer, feminist, Indigenous, vitalist, and other emergent theories and cinematic practices. The collection also demonstrates the unique ways that cinema studies scholarship is actively addressing environmental injustice and the climate crisis. This book is an invaluable resource for students and scholars of ecocritical film and media studies, production studies, cultural studies, and environmental studies

    NASA Tech Briefs, September 2001

    Get PDF
    Topics include: special coverage section on sensors, and sections on electronic components systems, software, materials, machinery/automation, manufacturing/fabrication, bio-medical, book and reports, and a special section of Photonics Tech Briefs

    Ecocinema Theory and Practice 2

    Get PDF
    This second volume builds on the initial groundwork laid by Ecocinema Theory and Practice by examining the ways in which ecocritical cinema studies have matured and proliferated over the last decade, opening whole new areas of study and research. Featuring fourteen new essays organized into three sections around the themes of cinematic materialities, discourses, and communities, the volume explores a variety of topics within ecocinema studies from examining specifc national and indigenous flm contexts to discussing ecojustice, environmental production studies, flm festivals, and political ecology. The breadth of the contributions exemplifes how ecocinema scholars worldwide have sought to overcome the historical legacy of binary thinking and intellectual norms and are working to champion new ecocritical, intersectional, decolonial, queer, feminist, Indigenous, vitalist, and other emergent theories and cinematic prac-tices. The collection also demonstrates the unique ways that cinema studies scholarship is actively addressing environmental injustice and the climate crisis. This book is an invaluable resource for students and scholars of ecocritical flm and media studies, production studies, cultural studies, and environmental studies.https://cupola.gettysburg.edu/books/1181/thumbnail.jp

    Ecocinema Theory and Practice 2

    Get PDF
    This second volume builds on the initial groundwork laid by Ecocinema Theory and Practice by examining the ways in which ecocritical cinema studies have matured and proliferated over the last decade, opening whole new areas of study and research. Featuring fourteen new essays organized into three sections around the themes of cinematic materialities, discourses, and communities, the volume explores a variety of topics within ecocinema studies from examining specific national and indigenous film contexts to discussing ecojustice, environmental production studies, film festivals, and political ecology. The breadth of the contributions exemplifies how ecocinema scholars worldwide have sought to overcome the historical legacy of binary thinking and intellectual norms and are working to champion new ecocritical, intersectional, decolonial, queer, feminist, Indigenous, vitalist, and other emergent theories and cinematic practices. The collection also demonstrates the unique ways that cinema studies scholarship is actively addressing environmental injustice and the climate crisis. This book is an invaluable resource for students and scholars of ecocritical film and media studies, production studies, cultural studies, and environmental studies
    • …
    corecore