计算网格QoS-aware作业调度的建模与性能评价

为了提高计算网格的服务质量(QoS),研究了包含多层调度器的分级分布式网格体系结构中的QoS-aware作业调度问题,提出了一种将计算网格本地调度器作业选择中所使用的作业优先级与全局调度器的作业分配策略相结合的QoS-aware作业调度综合控制策略.建立了一个具有2层调度器的计算网格的随机高级Petri网(SHLPN)模型,并且进行模型精化设计以降低模型求解的复杂性.使用基于SHLPN的性能分析技术进行系统性能评价.数值结果显示QoS-aware作业调度策略能够为高优先级的作业提供较QoS-unaware作业调度策略更好的QoS保证.     

动态车辆调度系统的滚动时域调度算法

提出了一类特殊的动态车辆调度问题--动态独占性带时间窗口装卸货问题.给出了问题的数学描述,分析了其静态性质,并把问题简化为不对称带时间窗口旅行商问题.提出了求解该动态问题的滚动时域调度算法,通过时域的不断滚动,不仅可以跟踪问题的动态变化,还由于每次滚动只对部分客户进行处理,可以减少问题的求解时间.并分析了算法的3个要素:当前客户窗口、当前客户窗口的调度和滚动策略.测试结果验证了算法在求解动态车辆调度问题中的有效性.     

面向MPEG-4流的交换机调度算法

为解决MPEG-4流传输过程中传统的交换机调度算法导致的普通数据队列包丢失及增强层有较大的延时和延时抖动问题,采用了改进算法,首先,将到达每个输出端口的数据按照优先级分成3组;其次,根据每组的特性采用动态优先级算法实现,设计了一个动态的线性优先级计算函数,该函数的输入参数是每个队列的优先级和在每一队列中的待发送的数据包数,传输的优先级随之动态改变.实验证明,提出的算法能够保证MPEG-4基本层的传输,根据网络带宽状况允许更多的MPEG4增强子层通过,比传统的交换机调度算法提高了MPEG-4流传输的服务质量,更好地支持了流传输.     

Efficient genetic algorithm for resource-constrained project scheduling problem

This paper presents a new genetic algorithm for the resource-constrained project scheduling problem(RCPSP).The algorithm employs a standardized random key(SRK) vector representation with an additional gene that determines whether the serial or parallel schedule generation scheme(SGS) is to be used as the decoding procedure.The iterative forward-backward improvement as the local search procedure is applied upon all generated solutions to schedule the project three times and obtain an SRK vector,which is rese...     

一种改进的启发式网格任务调度算法

互联网技术的发展，硬件技术和通信技术的进步 共同加快了计算机领域前进的步伐。20世纪80年代 出现了并行计算，支持同步的算法、程序和体系结构相 继被开发。随后出现了分布计算，它要求各个处理机 之间能够协同计算，通过处理机间的通信共同解决问 题。网格计算技术的发展适     

一种全局QoS感知服务组合的权重设计方法

基于全局QoS感知的服务组合可以通过加权聚合的方式构建为一个单目标优化问题,此时需要一个合适的方法去估算权重,为此提出了一种基于非均匀空间理想加权距离的权重合成方法.该方法考虑用户的全局定性需求,首先运用G1法生成主观权重,然后使用熵权法计算各组合点上QoS属性的内在客观权重;最后给出非均匀空间距离计算方法,结合逼近理想法设计合成权重.构建于QWS数据集上的实验,阐述了合成权重的计算过程和评估了相关参数对权重的影响.结果表明,合成权重能够综合反映用户的偏好和QoS属性的内在特征.     

两个加工时间恶化的半线性平行机排序问题的启发式MBLS 算法

The combination of online or semi-online with deterioration jobs has never been researched in scheduling problems. In this paper, two semi-online parallel machine scheduling problems with linear deterioration processing time are considered. In the first problem, it is assumed that the deterioration rates of jobs are known in an interval, that is, bj ∈[0, α], where 0 〈α≤ 1 and bj denotes the linear deterioration rate. In the second problem, it is assumed that the largest deterioration rate of jobs is known in advance, that is, b = max1≤j≤n {bj }. For each of the two problems, a heuristic MBLS algorithm is worked out and its worst-case ratio is analyzed. At the same time, the worst-case ratio of the list （LS） algorithm is investigated and it is proved that all the ratios are tight.     

基于智能排课算法的设计与实现

本文根据回溯、递归等算法思想,解决了排课过程中死锁的问题。通过具体分析,实现了该算法,为排课系统智能化打下了基础。     

作业车间调度问题解的不可行性检测算法和快速修复算法

为了判别作业车间调度问题的解的可行性,提出了一种基于图论的启发式判别算法,并通过实例验证了方法的正确性.提出了普适于作业车间调度问题的快速修补新算法,可以对于作业车间调度问题的不可行解进行修正使之变成可行解.判别算法和修补算法在最不利情形下的计算复杂性均为O(n),判别算法在最有利情形下的计算复杂性为O(2 |J|+|...     

关于简单线性恶化问题的平行机排序的一个全多项式逼近算法

In this paper, a parallel machine scheduling problem was considered , where the processing time of a job is a simple linear function of its starting time. The objective is to minimize makespan. A fully polynomial time approximation scheme for the problem of scheduling n deteriorating jobs on two identical machines was worked out. Furthermore, the result was generalized to the case of a fixed number of machines.     

Genetic algorithm for scheduling reentrant jobs on parallel machines with a remote server

This paper considers a reentrant scheduling problem on parallel primary machines with a remote server machine, which is required to carry out the setup operation. In this problem, each job has three operations. The first and last operations are performed by the same primary machine, implying the reentrance, and the second operation is processed on the single server machine. The order of jobs is predetermined in our context. The challenge is to assign jobs to the primary machines to minimize the makespan. We develop a genetic algorithm（GA） to solve this problem. Based on a simple strategy of assigning jobs in batches on the parallel primary machines, the standardized random key vector representation is employed to split the jobs into batches. Comparisons among the proposed algorithm, the branch and bound（BB） algorithm and the heuristic algorithm, coordinated scheduling（CS）, which is only one heuristic algorithm to solve this problem in the literature, are made on the benchmark data. The computational experiments show that the proposed genetic algorithm outperforms the heuristic CS and the maximum relative improvement rate in the makespan is 1.66%.     

与开工时间有关的加工时间的超前有奖迟后受罚的排序问题的动态规划算法

In this paper, a single-machine scheduling model with a given common due date is considered. Job processing time is a linear decreasing function of its starting time. The objective function is to minimize the total weighted earliness award and tardiness penalty. Our aim is to find an optimal schedule so as to minimize the objective function. As the problem is NP-hard, some properties and polynomial time solvable cases of this problem are given. A dynamic programming algorithm for the general case of the problem is provided.     

Optimal online algorithms for scheduling on two identical machines under a grade of service

INTRODUCTIONWe study the problem of online scheduling on two identical parallel machines with a new feature that service requests from various customers are entitled to many different grade of service (GoS) levels. The goal is to minimize the makespan under the constraint that all requests are satisfied. This problem was first proposed by Hwang et al.(2004) and is motivated by the following scenario. In the service industry, the service providers often have special customers, such as, go…     

Algorithms for semi on-line multiprocessor scheduling problems

In the classical multiprocessor scheduling problems, it is assumed that the problems are considered in off-line or on-line environment. But in practice, problems are often not really off-line or on-line but somehow in between. This means that, with respect to the on-line problem, some further information about the tasks is available, which allows the improvement of the performance of the best possible algorithms. Problems of this class are called semi on-line ones. The authors studied two semi on-line multiprocessor scheduling problems, in which, the total processing time of all tasks is known in advance, or all processing times lie in a given interval. They proposed approximation algorithms for minimizing the makespan and analyzed their performance guarantee. The algorithms improve the known results for 3 or more processor cases in the literature. Project supported by the National Natural Science Foundation of China (Nos. 19701028 and 19971078) and National 973 Research Project of China.     

自动排课模型算法分析与研究

本文总结了模型排课问题的需求分析,通过采用回溯,递归等算法解决自动排课过程中死锁的问题,提出了自动排课模型算法,为具体运用提供了参考。     

Distributed QoS-aware source-specific multicast routing protocol

1 Introduction 1 Multiparty applications based on group communication such as video conference, remote education and so on are expected to become widespread in the Internet in the future. Now, the network transmission mode is unicast with a single receiver. If there are multiple receivers, the sender has to transmit multiple copies of the same data. Obviously, the unicast is inefficient for increasing one-to-many and many-to-many network applications. Multicast (RFC1112) is one of the effect…     

Fuzzy flexible resource constrained project scheduling based on genetic algorithm

Both fuzzy temporal constraint and flexible resource constraint are considered in project scheduling. Inorder to obtain an optimal schedule, we propose a genetic algorithm integrated with concepts on fuzzy set theory aswell as specialized coding and decoding mechanism. An example demonstrates that the proposed approach can assistthe project managers to obtain the optimal schedule effectively and make the correct decision on skill training before aproject begins.     

基于Hadoop平台的作业调度算法研究

爆炸式增长的数据要求高效率地使用计算资源,Hadoop是解决大数据处理的一个方向,不过Ha-doop平台还处于发展中,很多地方还有待完善。对Hadoop自带的三种调度器的优缺点进行分析,针对希望区分和动态改变作业服务质量的情况提出了动态优先调度算法。实验结果表明动态优先调度算法能够在作业的运行中动态改变作业的优先级,在效率上也有所提升。     

长释放时间间隔优先调度算法及其可调度性分析

针对混合任务实时调度的需求和现有混合任务实时调度算法的局限性,提出了一种长释放时间间隔优先的混合任务实时调度算法LRIF,该算法采用固定优先级和动态优先级相结合的调度策略,根据非周期性软实时任务作业到达流分布,将一定比例的软实时任务作业当作硬实时作业调度,除了可对周期性硬实时任务提供调度保证外,同时还可确保非周期性软实时任务的可调度率.还提出了LRIF调度算法的可调度性分析方法,并讨论了LRIF调度算法的实现方法.测试结果表明:LRIF调度算法具有更好的调度性能,可有效调度由周期性硬实时任务和非周期性软实时任务构成的混合实时系统.