共查询到19条相似文献,搜索用时 203 毫秒
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城市道路干线交叉口交通信号的配时优化控制直接影响了整个城市的交通状况。为了提高干线交叉口信号控制的效率,以干线交叉口模型的交通信号控制问题为背景,构造了基于最小延误的常态交通条件下干线双向绿波控制模型。同时,结合混沌理论和遗传算法各自的优势,开发了混沌遗传算法。通过该算法对模型进行仿真数据求解,并与传统优化算法相比,系统延误明显减少了。结果表明,基于混沌遗传算法的控制优化方法可以提高干线交通运行的效率。 相似文献
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以化工产品运输为例阐述了运输优化模型,利用线性规划算法对化工产品的运输方案进行优化,直接生成全局最优的最细粒度的运输方案,保证了运输方案的科学性。在运输优化模型应用过程中,采用时间序列对单位运输成本进行预测,解决单位运输成本初次运输无法获取以及单位运输成本更新的问题。在化工销售决策系统引入运输优化模型后,提高了运输决策的科学性,大幅降低了运输方案制定的难度及化工产品的运输成本。 相似文献
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为了提高船公司集装箱运输效率,降低运输成本,应用线性规划的方法,以租箱成本和集装箱空箱调运费用之和最低为目标,建立了海运集装箱空箱调运问题的优化模型。利用LINGO软件能够求得线性规划问题最优解的特点,编写了求解该问题的LINGO程序代码,通过实例验证,该模型和算法可以快速有效求得最优解。 相似文献
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本文以基于隐马尔科夫模型的语音识别系统为基线系统,提出了一种基于遗传算法的语法网络搜索方法,应用于语音识别系统的语法网络搜索模块。通过遗传算法解码得到的搜索结果虽然不唯一但都是满意解,提升了该模块的全局优化搜索能力。 相似文献
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Berry L.T.M. Murtagh B.A. McMahon G. Sugden S. Welling L. 《Telecommunication Systems》1999,12(2-3):265-280
In this paper we demonstrate success with an implementation of a genetic algorithm, integrated with linear programming, for
solving a minimum cost network synthesis problem. The problem is formulated to include a number of practical constraints and
the technique applied to moderately large networks (50 nodes). The associated linear program may be large but successful methods
have been developed with very small population sizes for the genetic algorithm.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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在WLAN中,延迟有限,网络整体消耗能量最小化的功率控制算法研究较少。对于该问题进行建模分析,通过理论推导,将该非凸优化问题转化成广义几何规划问题。经过分析,将问题近似为线性规划,并给出全局优化算法。对于WLAN中,多个无线接入设备在一定传输时间内的信道情况进行预测,给出延迟有限能量最小化的集中式在线算法。实验结果显示,采用提出的信道预测方法,在线算法的计算结果与集中式算法结果较为接近。 相似文献
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An efficient communication relay placement algorithm for content‐centric wireless mesh networks
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Jin Wang Kejie Lu Shukui Zhang Jianxi Fan Yanqin Zhu Baolei Cheng 《International Journal of Communication Systems》2015,28(2):262-280
In this paper, we investigate a communication relay placement problem to optimize the network throughput in a content‐centric wireless mesh networks (WMN), in which the WMN is enhanced by including a small set of communication relays and a subset of wireless mesh routers serving as storage nodes. Specifically, we first define the communication relay placement problem in content‐centric WMNs. We then model the problem as a mathematical programming and propose a linear programming approach for calculating the achievable network throughput when the positions of communication relays are fixed. Next, to optimally placing the communication relays, we formulate an integer linear programming problem and we develop an efficient near‐optimal approximation algorithm based on linear programming relaxation. Finally, extensive simulation experiments have been conducted, and the results demonstrate the effectiveness of the proposed algorithms. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Aiming at the scenarios which consider the constraint of backhaul capacity restriction and interference threshold in ultra-dense networks (UDN),an integer linear programming (ILP) and Lagrangian dual decomposition (LDD) based joint optimization algorithm of energy efficiency and spectrum efficiency was proposed.In the proposed algorithms,the user association problem with the constraint of limited backhaul capacity was modelled as an ILP problem and then finished the connection between the user and the base station of microcell by solving this problem with dynamic programming method.Therefor,Lagrangian dual decomposition (LDD) was applied in an iteration algorithm for spectrum resource allocation and power allocation.The simulation results show that compared with traditional schemes,the proposed algorithm can significantly improve the energy efficiency and spectrum efficiency of system and use the microcell’s load capacity more efficiently. 相似文献
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Due to limited spectrum resources and differences in link loads, network congestion is one of the key issues in cognitive radio wireless mesh networks. In this letter, a congestion avoidance model with power control, channel allocation, and routing under the signal‐to‐interference‐and‐noise ratio is presented. As a contribution, a nested optimization scheme combined with a genetic algorithm and linear programming solver is proposed. Extensive simulation results are presented to demonstrate the effectiveness of our algorithm. 相似文献
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Maximum lifetime routing in wireless sensor networks 总被引:11,自引:0,他引:11
A routing problem in static wireless ad hoc networks is considered as it arises in a rapidly deployed, sensor based, monitoring system known as the wireless sensor network. Information obtained by the monitoring nodes needs to be routed to a set of designated gateway nodes. In these networks, every node is capable of sensing, data processing, and communication, and operates on its limited amount of battery energy consumed mostly in transmission and reception at its radio transceiver. If we assume that the transmitter power level can be adjusted to use the minimum energy required to reach the intended next hop receiver then the energy consumption rate per unit information transmission depends on the choice of the next hop node, i.e., the routing decision. We formulate the routing problem as a linear programming problem, where the objective is to maximize the network lifetime, which is equivalent to the time until the network partition due to battery outage. Two different models are considered for the information-generation processes. One assumes constant rates and the other assumes an arbitrary process. A shortest cost path routing algorithm is proposed which uses link costs that reflect both the communication energy consumption rates and the residual energy levels at the two end nodes. The algorithm is amenable to distributed implementation. Simulation results with both information-generation process models show that the proposed algorithm can achieve network lifetime that is very close to the optimal network lifetime obtained by solving the linear programming problem. 相似文献
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多热源选址问题是一个多变量、多约束条件的线性规划问题。本文以遗传算法的基本思想为基础,对变异选择算子做了改进,并采取了字符编码技术而有效地压缩了约束条件,用二次选择的策略成功地加快了收敛进程,从而求得了多热源选址的全局最优解。 相似文献