Despite the numerous advantages reconfigurable computing adds to a system, it is only advantageous if the execution time exceeds the configuration time. As a result of the long configuration time, reconfiguration is o...
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ISBN:
(纸本)9781467321648
Despite the numerous advantages reconfigurable computing adds to a system, it is only advantageous if the execution time exceeds the configuration time. As a result of the long configuration time, reconfiguration is only suitable for quasi-static applications. Due to the additional overhead required for communication, the bus-based architectures most commonly used to connect the configuration controller to the memory contribute to the configuration time. A method proposed to ameliorate this overhead is an architecture utilizing localized block RAM (BRAM), directly connected to the configuration controller to store the configuration data. the drawback of this method is that the BRAM is extremely limited and only a discrete set of configurations can be stored. this paper is a work in progress and proposes a hardware reconfiguration architecture that addresses the size limitation of the localized BRAM-architecture by using parameterizable configuration. this will allow a single bitstream stored in the BRAM to be specialized according to certain parameters, which will be used to reconfigure the device. this will migrate reconfigurable computing to more dynamic applications. the architecture proposed in this paper will be validated using real-time PID control of a five degree of freedom active magnetic bearing system.
D-ReServE increases reliability of SOA-based systems in case of failure occurrence. the fault-tolerant information in D-ReServE is stored in the Stable Storage, which available space depletes withtime. thus, in this ...
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ISBN:
(纸本)9781467357043
D-ReServE increases reliability of SOA-based systems in case of failure occurrence. the fault-tolerant information in D-ReServE is stored in the Stable Storage, which available space depletes withtime. thus, in this paper we propose a garbage collection protocol for D-ReServE that allows the periodic purging of the Stable Storage, and discuss the challenges of garbage collection due to the nature of SOA systems.
the following topics are dealt with: software life cycle, evolution and maintenance; reliability, metrics and fault tolerance; software testing; trustworthiness of open source, open data, open systems and open standar...
the following topics are dealt with: software life cycle, evolution and maintenance; reliability, metrics and fault tolerance; software testing; trustworthiness of open source, open data, open systems and open standards; software architecture and design; security; software testing, software quality and trust in software-based systems; requirements engineering; creative computing: reconciling objective precision with subjective ambiguity; formal method; cloud computing; Web-based system; a perspective of software trustworthiness based on finance industry; smart and semantic computing; HCI and usability; cloud computing for developing countries; mobile and pervasive computing; and real-time and embeddedsystems.
Online videos are one of the most prevalent forms of communication over the Internet because humans are attracted to visual stimulations. Multimedia services, especially real-time services, require data to arrive on t...
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Online videos are one of the most prevalent forms of communication over the Internet because humans are attracted to visual stimulations. Multimedia services, especially real-time services, require data to arrive on time. Unlike any other transmissions, video streaming needs to be monitored and adapted to bandwidth, when the video stream passes through the best-effort environment. A guaranteed QoS (Quality of Service) is essential in all real-timeapplications. this paper presents a context aware mechanism, which improves the QoS of realtime video transmission, over wireless networks. this proposed RSQA system ensures video availability even when the bandwidth is low. Drawbacks to other solutions for saving bandwidth in real-time include being: (1) too expensive due to requiring a priority based router (in the case of proxy based and frame prioritization approaches); (2) too complex; (3) not appropriate for real-timesystems. this RSQA system succeeds in being of low complexity, appropriate for real-timesystems and cost effective (not requiring a priority based router to function). this RSQA system is independent of wireless technology making, thus it appropriate for use in a heterogeneous environment as well. Whenever a user experiences packet loss or a delay in receiving a video, the server will be notified about the congestion and decrease the video quality to make the video available at low bandwidth. the decision regarding the needed QoS parameters and the rate control is based on context information (available bandwidth). the RTP (real-time Transport Protocol) based streaming is simulated and verified by an Eclipse simulator and Java using an MJPEG standard. Results show that the QoS parameters of video transmission were improved considerably by this RSQA system.
this paper presents an overview of the current state-of-the-art in mobile data stream mining. this area of mobile data stream mining is significant for a number of new application domains such as mobile crowd sensing ...
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this paper presents an overview of the current state-of-the-art in mobile data stream mining. this area of mobile data stream mining is significant for a number of new application domains such as mobile crowd sensing and mobile activity recognition. the paper presents the strategies and techniques for adaptation that are essential in order to perform real-time, continuous data mining on mobile devices. We present an overview of the algorithms research in this area. Finally, we discuss the key toolkits, systems and applications of mobile data stream mining.
real-time group communication is fundamental to many emerging interactive multimedia applications. Communication among the group members is N-to-N in that any number of group members may generate data and control pack...
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real-time group communication is fundamental to many emerging interactive multimedia applications. Communication among the group members is N-to-N in that any number of group members may generate data and control packets destined to all the other members at the same time. Redundancy Reduction Gossip (RRG) is a highly effective real-time N-to-N dynamic group protocol over the Internet and demonstrates churn and sporadic traffic coping capability. In this paper, a peer-to-peer (P2P) real-time group communication protocol based on RRG is proposed for Content-Centric Network (CCN). A highly effective synergy between RRG and the capability of CCN is exploited. Effects include connectivity expansion, traffic reduction and latency improvement. the proposed protocol allows information distributed from an arbitrary number of dynamic sources in a group. It has low latency and minimal membership maintenance.
Achieving quality of service (QoS) in ieee 802.16 networks depends, among other factors, on mechanisms for traffic policing at the base station (BS) and subscriber stations (SSs). Since ieee 802.16 does not include a ...
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Achieving quality of service (QoS) in ieee 802.16 networks depends, among other factors, on mechanisms for traffic policing at the base station (BS) and subscriber stations (SSs). Since ieee 802.16 does not include a mandatory policing, this paper proposes a policing mechanism for the SS in the uplink traffic which uses the leaky bucket mechanism (token bucket). the performance evaluation studies based on modeling and simulation have shown that the proposed mechanism is able to ensure satisfactory levels of QoS to applications, meeting their average limited delay requirements, minimum sustainable throughput and limited packet drop rate.
the recent data deluge needing to be processed represents one of the major challenges in computational field. Available high-performance computing (HPC) systems can be very useful for solving this problem when data ca...
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the recent data deluge needing to be processed represents one of the major challenges in computational field. Available high-performance computing (HPC) systems can be very useful for solving this problem when data can be divided in chunks that can be processed in parallel. However, due to intrinsic characteristics of data-intensive problems, these applications can present huge load imbalances, and it can be difficult to efficiently use the available resources. this work proposes a strategy for dynamically analyzing and tuning the partition factor used to generate the data chunks. Withthe aim of decreasing the load imbalance and therefore the overall execution time, this strategy divides the data chunks withthe biggest computation times and gathers contiguous chunks withthe smallest computation times. the criteria to divide or join chunks are based on the chunks' associated execution time (average and standard deviation) and the number of processing nodes being used. We have evaluated our strategy by using simulation, and a real data-intensive application. Applying our strategy, we have obtained promising results since we have improved up to 55% the total execution time.
Collaborative Augmented reality (CAR) systems allow multiple users to share a real world environment including computer-generated images in realtime. Currently, the hardware features of most mobile phones provide exc...
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Collaborative Augmented reality (CAR) systems allow multiple users to share a real world environment including computer-generated images in realtime. Currently, the hardware features of most mobile phones provide excellent multimedia services, and it also includes wireless network capabilities that offer a natural platform for CAR systems. However, the performance of the mobile CAR applications under different conditions, like the number and type of devices in the system, has not been studied yet. this paper presents the experimental characterization of CAR systems based on mobile phones, providing quantitative results about well-known performance metrics in distributed systems like system throughput and system response times. the characterization results show that the system saturation point depends on the overall percentage of CPU utilization in the computer platform acting as the system server, although it is not a fixed value and it is inversely related to the number of processor cores. Also, the results show that throughput of CAR systems heavily depends on the kind of client devices, but CAR systems can efficiently support some hundreds of clients in any case. Another important result is that the CAR system throughput is limited by the server I/O in some cases. therefore, any improvement in CAR systems should be addressed to alleviate the server I/O, even though it may add computational overhead to the server.
It is well known that the performance of real-time control applications can be affected by many factors, including the choice (and configuration) of the hardware platform and task scheduling algorithm. this paper pres...
It is well known that the performance of real-time control applications can be affected by many factors, including the choice (and configuration) of the hardware platform and task scheduling algorithm. this paper presents a real-time hardware-in-the-loop simulation tool that simultaneously integrates concepts from control and real-timecomputing to allow further investigation into these links. It allows the experimental prototyping and analysis of real-time control systems on real hardware - but within a simulated plant environment -and thus allows the potential impacts of hardware and software architecture on control performance and dependability to be evaluated. the structure of the proposed tool is described, along with a preliminary experiment that has been performed to illustrate some of the test facility capabilities.
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