279 research outputs found

    Distributed Video Coding: Selecting the Most Promising Application Scenarios

    Get PDF
    Distributed Video Coding (DVC) is a new video coding paradigm based on two major Information Theory results: the Slepian–Wolf and Wyner–Ziv theorems. Recently, practical DVC solutions have been proposed with promising results; however, there is still a need to study in a more systematic way the set of application scenarios for which DVC may bring major advantages. This paper intends to contribute for the identification of the most DVC friendly application scenarios, highlighting the expected benefits and drawbacks for each studied scenario. This selection is based on a proposed methodology which involves the characterization and clustering of the applications according to their most relevant characteristics, and their matching with the main potential DVC benefits

    Quality of Service Control for WLAN-based Converged Personal Network Service

    Get PDF
    This paper proposes a framework for quality of service (QoS) control in WLAN-based converged personal network service (CPNS). First, we show that the CPNS devices in WLANs occupy the shared wireless channel in an unfair manner; and thus, QoS is degraded. The reasons of such problem are analyzed from two viewpoints of (i) channel access mechanism according to carrier sensing multiple access protocol of WLAN and (ii) TCP congestion control mechanism in response to packet loss. To improve QoS and assure fair channel sharing, we propose an integrated QoS control framework consisting of admission control and rate control. Based on the available capacity, the admission control determines whether or not a specific QoS service can be admitted. The rate control is implemented using congestion window control or token bucket algorithm. The proposed mechanism differentiates QoS service from best-effort (BE) service such that the QoS service is preferentially served to satisfy its QoS requirements and the BE service is served to share the remaining resource in a fair manner. The extensive simulation results confirm that the proposed scheme assures QoS and fair channel sharing for WLAN-based CPNS

    TechNews digests: Jan - Nov 2008

    Get PDF
    TechNews is a technology, news and analysis service aimed at anyone in the education sector keen to stay informed about technology developments, trends and issues. TechNews focuses on emerging technologies and other technology news. TechNews service : digests september 2004 till May 2010 Analysis pieces and News combined publish every 2 to 3 month

    The digital media lab at Bainbridge College

    Get PDF
    This project describes the development of an audio and video production facility at Bainbridge College, a small community college in Bainbridge, Georgia. The Digital Media Lab provides faculty, staff, and students with the ability to create audio and video resources for classroom use, research, training, and outreach. The principal steps of this project were a literature review, a needs analysis, the equipment selection process, and implementation. The literature review included examples of how video is used in higher education, information about current trends in technology, and faculty development strategies. The needs analysis determined that the facility should support both analog and digital media and that a facility where users could work independently was most practical. A list of equipment, user guidelines, outlines of current workshops, and samples of quick reference materials used in the lab are also included in this report

    MedLAN: Compact mobile computing system for wireless information access in emergency hospital wards

    Get PDF
    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.As the need for faster, safer and more efficient healthcare delivery increases, medical consultants seek new ways of implementing a high quality telemedical system, using innovative technology. Until today, teleconsultation (the most common application of Telemedicine) was performed by transferring the patient from the Accidents and Emergency ward, to a specially equipped room, or by moving large and heavy machinery to the place where the patient resided. Both these solutions were unpractical, uneconomical and potentially dangerous. At the same time wireless networks became increasingly useful in point-of-care areas such as hospitals, because of their ease of use, low cost of installation and increased flexibility. This thesis presents an integrated system called MedLAN dedicated for use inside the A&E hospital wards. Its purpose is to wirelessly support high-quality live video, audio, high-resolution still images and networks support from anywhere there is WLAN coverage. It is capable of transmitting all of the above to a consultant residing either inside or outside the hospital, or even to an external place, thorough the use of the Internet. To implement that, it makes use of the existing IEEE 802.11b wireless technology. Initially, this thesis demonstrates that for specific scenarios (such as when using WLANs), DICOM specifications should be adjusted to accommodate for the reduced WLAN bandwidth. Near lossless compression has been used to send still images through the WLANs and the results have been evaluated by a number of consultants to decide whether they retain their diagnostic value. The thesis further suggests improvements on the existing 802.11b protocol. In particular, as the typical hospital environment suffers from heavy RF reflections, it suggests that an alternative method of modulation (OFDM) can be embedded in the 802.11b hardware to reduce the multipath effect, increase the throughput and thus the video quality sent by the MedLAN system. Finally, realising that the trust between a patient and a doctor is fundamental this thesis proposes a series of simple actions aiming at securing the MedLAN system. Additionally, a concrete security system is suggested, that encapsulates the existing WEP security protocol, over IPSec

    Spread and SpreadRecorder An Architecture for Data Distribution

    Get PDF
    The Space Acceleration Measurement System (SAMS) project at the NASA Glenn Research Center (GRC) has been measuring the microgravity environment of the space shuttle, the International Space Station, MIR, sounding rockets, drop towers, and aircraft since 1991. The Principle Investigator Microgravity Services (PIMS) project at NASA GRC has been collecting, analyzing, reducing, and disseminating over 3 terabytes of collected SAMS and other microgravity sensor data to scientists so they can understand the disturbances that affect their microgravity science experiments. The years of experience with space flight data generation, telemetry, operations, analysis, and distribution give the SAMS/ PIMS team a unique perspective on space data systems. In 2005, the SAMS/PIMS team was asked to look into generalizing their data system and combining it with the nascent medical instrumentation data systems being proposed for ISS and beyond, specifically the Medical Computer Interface Adapter (MCIA) project. The SpreadRecorder software is a prototype system developed by SAMS/PIMS to explore ways of meeting the needs of both the medical and microgravity measurement communities. It is hoped that the system is general enough to be used for many other purposes

    Paper Session II-D - Establishing a Real-Time Multimedia Link to the Arctic

    Get PDF
    On July 27th, 1998, the National Aeronautics and Space Administration\u27s (NASA) Learning Technologies (LT) Project and the United States Coast Guard (USCG) implemented the world\u27s first real-time multimedia link between the USCG Cutter Polar Star (Polar Star) located in the Gulf of Alaska and schools from as far west as Japan across the entire United States. This link allowed students to enjoy the benefits of leading-edge technology. The effort was built upon LT\u27s existing cadre of technology and was taken to a new height when placed aboard the Polar Star. The Polar Star was the second U.S. ship to implement a mobile high-speed data link connected to the Internet using lnmarsat via Intelsat 178° E. This technology was further developed to produce events from Ice Station Sheba located at 79° N

    CCTV Technology Handbook

    Get PDF
    This CCTV Technology Handbook provides emergency responders, law enforcement security managers, and other security specialists with a reference to aid in planning, designing, and purchasing a CCTV system. This handbook includes a description of the capabilities and limitations of CCTV components used in security applications
    • …
    corecore