8279890
Location tracking using quorums in mobile ad hoc networks
Abstract We explore applications of quorum systems to the problem of tracking locations of mobile users in mobile ad hoc networks (MANETs). The location tracking system uses biquorum systems, a generalization of traditional quorum systems. We performed extensive simulations of the location tracking system. The simulation results show that our strict biquorum implementation has better performance than the traditional strict quorum implementations. Moreover, our results show that randomized dynamic quorum implementations have better overall performance than strict (bi)quorum implementations.
8052541
Applications of probabilistic quorums to iterative algorithms
Presents a definition of a read-write register that sometimes returns out-of-date values, shows that the definition is implemented by the probabilistic quorum algorithm of D. Malkhi et al. (1997), and shows how to program with such registers using the framework of A. U/spl uml/resin and M. Dubois (1990). Consequently, existing iterative algorithms for an interesting class of problems (including finding shortest paths, constraint satisfaction and transitive closure) converge with high probability if executed in a system in which the shared data is implemented with registers satisfying the new definition. Furthermore, the algorithms in this framework inherit positive attributes concerning load and availability from the underlying register implementation. A monotone version of the new register definition is specified and implemented; it can provide improved expected convergence time and message complexity for iterative algorithms.
9646078
Parallel hashing algorithms on BSP and QSM models
Summary form only given. We study two parallel computing models - the bulk synchronous parallel (BSP) and the queued shared memory (QSM) - as alternatives to the PRAM model to provide more accurate performance predictions and analyses, and compares the two models in detail. As a case study, we consider a simple hashing problem, design the two versions - the message passing version and the shared memory version - of the algorithm, and compare their run time analytically. The message passing version of the algorithm is implemented and the experiments are performed to display the accuracy and the limitations of the predicted performance analysis.
6784159
Randomized registers and iterative algorithms
Abstract.We present three different specifications of a read-write register that may occasionally return out-of-date values - namely, a (basic) random register, a P-random register, and a monotone random register. We show that these specifications are implemented by the probabilistic quorum algorithm of Malkhi, Reiter, Wool, and Wright, and we illustrate how to program with such registers in the framework of Bertsekas, using the notation of Üresin and Dubois. Consequently, existing iterative algorithms for a significant class of problems (including solving systems of linear equations, finding shortest paths, constraint satisfaction, and transitive closure) will converge with high probability if executed in a system in which the shared data is implemented with registers satisfying the new specifications. Furthermore, the algorithms in this framework will inherit positive attributes concerning load and fault-tolerance from the underlying register implementation. The expected convergence time for iterative algorithms using the monotone implementation is analyzed and shown experimentally to improve on that of the original implementation. The message complexity for iterative algorithms using the monotone probabilistic quorum implementation is shown to improve on that of non-probabilistic implementations in a quantifiable situation.
37964793
Object-Oriented Design and Implementation of the OE-Scheduler in Real Time Environments
21234984
A distributed utility max-min flow control algorithm
A fair allocation of utility (application-layer performance) is essential in providing QoS (Quality of Service) guarantee. However, there have been few researches in the literature of utility-fair network resource allocation scheme. In this paper, we propose a distributed utility max-min flow control algorithm which accommodates application diversity in that it does not require the concavity of utility functions, and is scalable in that it does not require any per-flow operation in the network. The algorithm is proved to be convergent under the assumption that there exists a single bottleneck link and the communication delay between any two links in the network is bounded. Although the convergence of the algorithm is analyzed only for the case of a single bottleneck link, we show through simulations that the proposed algorithm works as designed for the case of multiple bottleneck links as well.
36948650
Constructing SSML Documents with Automatically Generated Intonation Information in a Combinatory Categorial Grammar Framework
As of now, Text-to-Speech (TTS) systems are widely used throughout the full spectrum of our activities, and various natural language processing techniques have been utilized to enhance the performance of such TTS systems. As TTS systems begin to play an important role for communication between human and machine, naturalness is considered the most crucial measure of performance for TTS systems, in addition to correctness. General statistical approaches, though widely adopted, are not appropriate for the phenomena as they assign the same intonation to the same sentence. We analyze various kinds of corpus to extract informative features for intonation generation in a Combinatory Categorial Grammar framework, and express intonation-annotated document using Speech Synthesis Markup Language for target system neutral application.
7244802
Design, implementation and testing of an interactive video retrieval system
In this paper we present and discuss the system we developed for the search task of the TRECVID 2002, and its evaluation in an interactive search task. To do this we will look at the strategy we used in designing the system, and we discuss and evaluate the experiments used to determine the value and effectiveness of one system incorporating both feature evidence and transcript retrieval compared to a transcript-only retrieval system. Both systems tested are built on the foundation of the Físchlár System developed and running for a number of years at the CDVP. The system is fully MPEG-7 compliant and uses XML for exchange of information within the overall architecture.
6879205
Mobile access to personal digital photograph archives
Handheld computing devices are becoming highly connected devices with high capacity storage. This has resulted in their being able to support storage of, and access to, personal photo archives. However the only means for mobile device users to browse such archives is typically a simple one-by-one scroll through image thumbnails in the order that they were taken, or by manually organising them based on folders. In this paper we describe a system for context-based browsing of personal digital photo archives. Photos are labeled with the GPS location and time they are taken and this is used to derive other context-based metadata such as weather conditions and daylight conditions. We present our prototype system for mobile digital photo retrieval, and an experimental evaluation illustrating the utility of location information for effective personal photo retrieval.