this paper presents a more efficient algorithm to count codewords of given weights in self-dual double-circulant and formally self-dual quadratic double-circulant codes over GF(2). A method of deducing the modular con...
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this paper presents a more efficient algorithm to count codewords of given weights in self-dual double-circulant and formally self-dual quadratic double-circulant codes over GF(2). A method of deducing the modular congruence of the weight distributions of the binary quadratic double-circulant codes is proposed. this method is based on that proposed by Mykkeltveit, Lam and McEliece, JPL. Tech. Rep., 1972, which was applied to the extended quadratic-residue codes. A useful application of this modular congruence method is to provide independent verification of the weight distributions of the extended quadratic-residue and quadratic double-circulant codes. Using this method in conjunction withthe proposed efficient codeword counting algorithm, we are able i) to give the previously unpublished weight distributions of the [76, 38,12] and [124, 62, 20] binary quadratic double-circulant codes; ii) to provide corrections to the published results on the weight distributions of the binary extended quadratic-residue code of prime 151, and the number of codewords of weights 30 and 32 of the binary extended quadratic-residue code of prime 137; and iii) to prove that the [168, 84, 24] extended quadratic-residue and quadratic double-circulant codes are inequivalent
distributed resource discovery is a crucial problem of dynamic and mobile system task environment. Most existing discovery studies are designated for the fixed infrastructure networks. In practice, the majority of the...
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distributed resource discovery is a crucial problem of dynamic and mobile system task environment. Most existing discovery studies are designated for the fixed infrastructure networks. In practice, the majority of the solutions have adopted centralized design and implementation strategies to locate the pool of resources. In this research, a means of virtualized and adaptive resource discovery is presented as a key entity of the study with an analytical model and adaptive algorithms for attribute based range queries. the proposed method is evaluated and discussed analytically. In addition, a scalable resource discovery overlay network is advocated. the design and implementation of the proof of concept are deliberated.
In pervasive computing, devices should be adaptive to changes in the need of users and respond to theses dynamical and unpredictable changes. An embedded Internet access server with dual-MCU(Microcontroller Unit) arch...
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In pervasive computing, devices should be adaptive to changes in the need of users and respond to theses dynamical and unpredictable changes. An embedded Internet access server with dual-MCU(Microcontroller Unit) architecture (DMCUEIAS) is presented in the paper, in the light of the question that the ratio of performance and cost of an embedded Internet access server with single MCU architecture is low and flexibility is weak. One MCU(InetMCU) that uses embedded thin TCP/IP protocol stack communicates with users through Internet, the other MCU (DevMCU) answers for the control of scene devices, the communications between both MCUs are based on the RAC (remote access control) protocol. the system architecture of dual-MCU makes the users and the devices control separate. the users not only watch over and control scene devices, but also download tasks to the scene devices through Internet. It solves the conflict between the low cost single MCU that runs slowly and the high cost single MCU that runs quickly.
Network researchers have dedicated a notable part of their efforts to the area of modeling traffic and to the implementation of efficient traffic generators. We feel that there is a strong demand for traffic generator...
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Network researchers have dedicated a notable part of their efforts to the area of modeling traffic and to the implementation of efficient traffic generators. We feel that there is a strong demand for traffic generators capable to reproduce realistic traffic patterns according to theoretical models and at the same time with high performance. this work presents an open distributed platform for traffic generation that we called distributed internet traffic generator (D-ITG), capable of producing traffic (network, transport and application layer) at packet level and of accurately replicating appropriate stochastic processes for both inter departure time (IDT) and packet size (PS) random variables. We implemented two different versions of our distributed generator. In the first one, a log server is in charge of recording the information transmitted by senders and receivers and these communications are based either on TCP or UDR In the other one, senders and receivers make use of the MPI library. In this work a complete performance comparison among the centralized version and the two distributed versions of D-ITG is presented. (c) 2004 Elsevier B.V. All rights reserved.
the use of distributedcomputing architectures has become commonplace in complex embedded systems with potential advantages, for example, in terms of scalability, dependability and maintainability. One particular area...
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ISBN:
(纸本)9780780394018
the use of distributedcomputing architectures has become commonplace in complex embedded systems with potential advantages, for example, in terms of scalability, dependability and maintainability. One particular area in which that trend can be witnessed is mobile autonomous robotics in which several sensors and actuators are interconnected by means of a control network. In this paper we address one case study concerning the CAMBADA robots that were developed at the University of Aveiro for the Robocup Middle Size League. these robots have a distributed architecture with two layers, a coordination layer responsible for the global behaviors and a distributed sensing and actuating layer that conveys internal state information and executes coordination commands. this paper focuses on the latter layer, which is based on the FTT-CAN protocol, following a network-centric approach that provides an efficient framework for the synchronization of all systems activities. We describe the computing and communication requirements, the robot architecture, the system design and implementation, and finally we provide experimental results that show advantages with respect to a non-synchronized distributed approach.
this paper introduces a GIS-supported scheduling model, BAL, for optimizing infrastructure maintenance programs involving multiple-distributed sites. BAL uses GIS to store site-specific information and to calculate di...
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this paper(1) presents an architecture to build distributed embedded real-time systems in the RTLinux-GPL platform. the architecture (built in a layered fashion) has being built around open source projects ranging fro...
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ISBN:
(纸本)9780780394018
this paper(1) presents an architecture to build distributed embedded real-time systems in the RTLinux-GPL platform. the architecture (built in a layered fashion) has being built around open source projects ranging from Ethernet drivers to a CORBA environment. the paper focuses on those layers that give support for QoS and real-time networking over Ethernet networks. the main ideas are: to accomplish deterministic access times by using a TDMA protocol over Ethernet and to multiplex different types of traffic in that real-time network, providing dill ferent service types (QoS) to each type of traffic without jeopardizing the a priori guarantee of the system's real-time properties. Traffic types include real-time messages, multimedia streams and conventional TCP/IP traffic. the traffic multiplexing is achieved using a modular packet scheduler based on the principles of Differentiated Services architecture. the paper describes in detail the design basics and analyzability of both implementations: a TDMA protocol and a traffic multiplexing (QoS) layer
this paper presents a nonlinear three-dimensional finite element model for composite beams subjected to uniformly distributed loads based on the use of the ANSYS software. the model allows for any pattern of shear con...
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in this paper, we design and develop a core-based multicast routing protocol in mobile ad-hoc networks. the network is modeled by a weighted graph model. Core is selected by the median node of the multicasting nodes. ...
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ISBN:
(纸本)9789806560628
in this paper, we design and develop a core-based multicast routing protocol in mobile ad-hoc networks. the network is modeled by a weighted graph model. Core is selected by the median node of the multicasting nodes. We design distributed core selection and adaptive core migration sub-protocols for mobile ad-hoc networks with dynamically changing network topology. We analyze the time complexities and run-time overhead of these sub-protocols. Finally, the fault tolerant feature of this core-based multicast routing protocol is also discussed.
the task of programming concurrent systems is substantially more difficult than the task of programming sequential systems with respect to both correctness and efficiency. this paper describes (1) a powerful mechanism...
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