This paper tackles the key scheduling problem of reducing the overall wait time of mobile clients in wireless data broadcast systems. It is observed that in periodic broadcast, new mobile clients may join in and exist...
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This paper tackles the key scheduling problem of reducing the overall wait time of mobile clients in wireless data broadcast systems. It is observed that in periodic broadcast, new mobile clients may join in and existing mobile clients may leave anytime; in on-demand broadcast, high uplink communication cost may occur as all clients have to submit their queries every time. These are likely to degrade existing broadcasting approaches. In this work, we study the scheduling problem of XML data broadcast in a hybrid mode, where the system supports both periodic broadcast and on-demand broadcast services at the same. By taking the structural similarity between XML documents into account, only a small portion of mobile clients would be involved in the scheduling process and all mobile clients can be served more effectively. In this way, communication cost at the client side can be reduced greatly. A formal theoretical analysis of the proposed technique is presented. Based on the analysis, a novel clustering-based scheduling algorithm is developed. Moreover, we utilize an aging method to predict the distribution of incoming queries based on small samples of queries from mobile clients. Finally, we evaluate the approach through a set of experiments and the results show that it can significantly improve access efficiency for mobile clients.
IEEE 802.11e HCCA reference scheduler is based on fixed value parameters that do not adapt to traffic changes, thus quality of service (QoS) for multimedia applications is a challenge, especially in the case of variab...
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IEEE 802.11e HCCA reference scheduler is based on fixed value parameters that do not adapt to traffic changes, thus quality of service (QoS) for multimedia applications is a challenge, especially in the case of variable bit rate (VBR) streams, that requires dynamic resource assignment. This paper is focused on immediate dynamic TXOP HCCA (IDTH) scheduling algorithm and its new evolution immediate dynamic TXOP HCCA plus (IDTH+). Their reclaiming mechanisms, refined by the monitoring of transmission duration, aim at overcoming the limits of fixed preallocation of resources by varying the stations transmission time and avoiding waste of resources. Simulations and theoretical analysis based on the imprecise computation model show that the integration of IDTH and IDTH+ can achieve improved network performance in terms of transmission queues length, mean access delay and packets drop rate, and to efficiently manage bursty traffic. Moreover, the performance improvements of IDTH+ with respect to IDTH are highlighted.
Many heuristics and intelligent methods have been proposed and applied in order to solve the Job Shop scheduling Problems (JSSP). Several researches have so far been interested in solving the production planning in JS...
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Many heuristics and intelligent methods have been proposed and applied in order to solve the Job Shop scheduling Problems (JSSP). Several researches have so far been interested in solving the production planning in JSSP and few of them have focused on solving production scheduling with the presence of maintenance tasks. This paper presents a new heuristic method (NHGA) that includes two new techniques. The first, is a Modified Genetic Algorithm (MGA) which is inspired from the different, steps of standard Genetic Algorithm is (GA). Practically, when the GA is used, usually many steps, such as crossover and mutation, are based on random choices. The idea of MGA technique is to enhance the random character of such choices through guiding the steps of GA in a logical procedure, while following at each generation and each step the most plausible solutions to solve the JSS problem with maintenance periods. Henceforth, the new modifications reported in the MGA take into consideration the initial population, selection, crossover, Mutation and the running mechanism of the algorithm. This has been sustained by a second technique called Heuristic Displacement of Genes (HDG) such a technique would take as an objective improving the obtained solutions of JSSP. the technique NHGA has been tasted on many benchmarks, and compared with standard GA and other recent methods. The obtained results actually shed light on the efficiency of our new heuristic method. (C) 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
An open shop scheduling problem based on a mechanical workshop is described here. The main objective is to find the sequence of jobs which minimizes the total flow time. For that reason, we first formulate the problem...
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This paper compares the quality and execution times of several algorithms for scheduling service based workflow applications with changeable service availability and parameters. A workflow is defined as an acyclic dir...
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This paper compares the quality and execution times of several algorithms for scheduling service based workflow applications with changeable service availability and parameters. A workflow is defined as an acyclic directed graph with nodes corresponding to tasks and edges to dependencies between tasks. For each task, one out of several available services needs to be chosen and scheduled to minimize the workflow execution time and keep the cost of service within the budget. During the execution of a workflow, some services may become unavailable, new ones may appear, and costs and execution times may change with a certain probability. Rescheduling is needed to obtain a better schedule. A solution is proposed on how integer linear programming can be used to solve this problem to obtain optimal solutions for smaller problems or suboptimal solutions for larger ones. It is compared side-by-side with GAIN, divide-and-conquer, and genetic algorithms for various probabilities of service unavailability or change in service parameters. The algorithms are implemented and subsequently tested in a real BeesyCluster environment.
Hybrid system class, which includes systems with piecewise continuous evolution and whose changes are related to the evolution of discrete variables are classically structured in three different levels, the controller...
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Hybrid system class, which includes systems with piecewise continuous evolution and whose changes are related to the evolution of discrete variables are classically structured in three different levels, the controller, the system and the interface. This kind of system is usually modeled through commutation models representing the whole system. Any reconfiguration process is therefore highly complex, as the calculation times are strongly linked to the size of the system. An adaptation of a holonic reference architecture on a hybrid system is proposed, this proposed model is composed of the union of the hybrid model and the holonic model, where the controller is represented by the product holon and the order holon, the interface is represented by the logical part of the resource holon, and finally the system is represented by the physical part of the resource holon. The aim of this paper is to evaluate the performance of a simple predictilib-reactive control using a holonic approach applied to a switch arrival system. Four configurations of study case are studied in simulation in order to evaluate the number of switches, whose optimal value is obtained thanks to a MILP model. (C) 2015, IFAC (International federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
This paper analyzes the key schedule algorithm of AES, presents its recursion model, and describes the relationship between the expanded key bytes. According to the features of key schedule of AES-256, we propose a ne...
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We consider an input queued switch operating under the MaxWeight scheduling algorithm. This system is interesting to study because it is a model for Internet routers and data center networks. Recently, it was shown th...
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This paper is devoted to the problem of designing a computational system utilizing the minimal number of processors to ensure that the program is executed before the deadline. The program is represented by a direct ac...
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ISBN:
(纸本)9783319175096;9783319175089
This paper is devoted to the problem of designing a computational system utilizing the minimal number of processors to ensure that the program is executed before the deadline. The program is represented by a direct acyclic graph where vertices correspond to jobs. The system is supposed to tolerate both hardware and software faults. The schedule of the program execution does not include the exact moments of job launch and termination, thus allowing to employ abstract models with various levels of detail to estimate the time of execution. A simulated annealing algorithm is proposed for this problem. The paper provides the proof of asymptotic convergence of the algorithm and an experimental evaluation. The algorithm is also applied to a practical problem of scheduling in radiolocation systems.
In this paper, we present a differential evolution algorithm with mixed strategy to solve the single machine total weighted tardiness problem. A coding rule is developed to enable the continuous differential evolution...
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