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使用可用度分配模型研究 总被引:3,自引:0,他引:3
使用可用性是某些复杂系统战备完好性的重要参数。将复杂系统按组成结构分成若干分系统,重点提出重要程度因素,并构建了重要度相同和不同的两种使用可用度模型,最后给出了混联系统的使用可用度分配模型及其求解方法。 相似文献
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Q2算法是新一代国际视频编码标准MPEG-4的标准码率控制算法,但在低码率和低延迟的实时视频通信中,Q2算法往往会导致编码图像质量产生剧烈的波动,大大降低了信宿端重建视频的视觉效果.为此,本文从机器学习的角度出发,提出了一种以最小二乘支持向量机在线建模的比特分配算法,用新算法取代Q2中的比特分配算法,设计出一个改进的Q2码率控制方案.实验仿真结果表明:与原始Q2方案相比,改进后的Q2码率控制方案取得了更加平稳、更加均衡的图像质量,极大地提高了视频通信的视觉质量. 相似文献
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Pricing Multicast Communication: A Cost-Based Approach 总被引:3,自引:0,他引:3
Multicast and unicast traffic share and compete for network resources. A cost-based approach to multicast pricing, based on accurate characterization of multicast scalability, will facilitate the efficient and equitable resource allocation between traffic types. Through the quantification of link usage, this paper establishes a multicast scaling relationship: the cost of a multicast distribution tree varies at the 0.8 power of the multicast group size. This result is validated with both real and generated networks, and is robust across topological styles and network sizes. Since multicast cost can be accurately predicted given the membership size, there is strong motivation to price multicast according to membership size. Furthermore, a price ceiling should be set to account for the effect of tree saturation. This tariff structure is superior to either a purely membership-based or a flat-rate pricing scheme, since it reflects the actual tree cost at all group membership levels. 相似文献
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Lambert Brian K. Walvekar Arun G. Hirmas Juan P. 《Reliability, IEEE Transactions on》1971,(3):182-185
This investigation presents a method for determining the optimum mean time between failures (MTBF), mean time to repair (MTTR), and the number of redundant units to use in a multistage system to achieve a given availability at minimum cost. The method (basically a dynamic programming algorithm) is illustrated by a three-stage example. 相似文献
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针对认知无线电中基于OFDM子载波分配ACG算法的计算复杂度高的这一缺点,提出了一种能降低计算复杂度的OFDM子载波分配算法。新的分配算法是通过运用设定方差门限值的方法把一些信道状态变化不大的连续子载波结合成子信道,从而将原来针对每个子载波的分配转变为针对子信道的分配,以此来降低频谱资源的分配次数。仿真分析表明,新的分配算法以牺牲少量频谱效益的代价,较之原有算法,明显地降低了计算复杂度。 相似文献
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在片上网络中实现通信流明确的应用,通常在编译过程中静态分配路径资源,并把路径分配算法嵌入到映射算法中综合考虑.针对现有基于遗传算法的片上网络路径分配算法,引入了一种完整路径均匀交叉算子,来改善现有算法中路径交叉不充分的问题.实验结果显示:使用新算子的路径分配算法优化了现有算法的结果,减少了计算时间. 相似文献
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Recent demand for mobile telephone service has been growing rapidly while the electro-magnetic spectrum of frequencies allocated for this purpose remains limited. Any solution to the channel assignment problem is subject to this limitation, as well as the interference constraint between adjacent channels in the spectrum. Channel allocation schemes provide a flexible and efficient access to bandwidth in wireless and mobile communication systems. In this paper, we present an efficient distributed algorithm for dynamic channel allocation based upon mutual exclusion model, where the channels are grouped by the number of cells in a cluster and each group of channels cannot be shared concurrently within the cluster. We discuss the algorithm and prove its correctness. We also show that the algorithm requires at most (worst case) O(N
gN
n logN
n) messages, where N
g is the number of groups and N
n is the number of neighbors. This is compared to Choy's algorithm which requires O(N
g
2N
n), where N
g is the number of groups and N
n is the number of neighboring cells in the system. We report our algorithm's performance with several channel systems using different types of call arrival patterns. Our results indicate that significant low denial rate, low message complexity and low acquisition time can be obtained using our algorithm. 相似文献
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Timsans Edward A. McNichols Roger J. Berry Stephen L. 《Reliability, IEEE Transactions on》1975,(5):333-335
This paper develops a technique for allocating the parameters, repair time and failure rate, to each component of a system at the lowest possible cost. The allocations are subject to the constraint of a required availability. To make an analytic solution possible, the assumptions of constant failure rates, s-independent components, series system, and no multiple failures were made. Each component is assumed to have a hyperbolic cost function associated with changing its failure rate and its repair time. A Lagrange Multiplier method was used to solve the problem. 相似文献
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研究了OFDM-SDMA系统中的资源分配算法问题,针对已有算法的不足,提出了一种新的多用户调度指标,并在此基础上提出了次优多用户调度算法。针对整数比特约束,采用了两种合适的资源分配方案。由于新指标充分考虑了被调度用户之间的空间兼容性和信道质量,仿真结果证明所提算法可以获得较好的性能增益,且资源分配算法的收敛速度较快。 相似文献
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本文研究OFDMA系统的资源分配问题,把该问题建模为一个在基站的总发射功率一定的条件下,使系统中各个用户的权重速率之和最大化的数学模型。并提出一种基于对偶分解的分布式资源分配算法,将该问题分解为一个关于基站的主问题以及若干个关于用户的子问题。各个用户可以通过对子问题的求解获得各自的子载波以及功率的分配方案;而基站通过对主问题的求解使得满足子载波与功率的分配能够满足约束条件的要求,实现各用户权重速率和最大化的优化目标。所提算法能够把一个复杂的优化问题分解为若干个独立的子问题进行并行求解,因此可以有效地降低计算的复杂度以及基站的运算量。仿真结果表明,该算法能够在较少的迭代步数内得到一个近似最优解。 相似文献
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提出了一种动态的云任务分配算法架构模型,其算法能将云任务平均分配到云群服务器中,充分考虑了不同云服务器针对不同业务能力,解决了云服务器的负载平衡,且能高效率地使用CPU资源,让使用者得到较高的服务效率,并让云群环境的计算及存储资源得到了有效管理.通过仿真比较分析,该技术是有效的,既能充分利用系统资源,又能实现资源的自动调节和负载均衡. 相似文献