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1.
针对智能水滴算法求解带时间窗车辆路径规划收敛速度慢、计算精度差的问题,根据带时间窗车辆路径问题的应用要求,利用整数线性规划方法,以配送车辆的最小运输总成本、最短运输距离和最少安排数量为目标,综合考虑了车辆出发点、服务点、装载量、行驶距离、服务时间窗等诸多约束条件,构建了多目标多时间窗车辆路径模型;为了精准快速求解多目标多时间窗车辆路径模型,提出一种鸽群-智能水滴互补改进优化算法,将河道水滴离散二进制变换后,采用地图罗盘算子和地标算子分别改进水滴的流动速度和方向,并利用自适应变邻域扰动策略干扰水滴携带的泥土量,提高水滴算法的开发和探索能力;利用理想点法和罚函数与多目标优化混合方法分别处理多目标函数与约束条件,并以两种经典的带时间窗车辆路径问题为实例,通过与遗传算法、智能水滴算法和鸽群-水滴算法的计算结果进行比较,结果表明:在相同的算法参数和经济指标下,鸽群-水滴算法相比于智能水滴算法求解模型中的运输路径缩短20 km左右、运输成本节约403元左右,且该算法的求解时间和迭代次数也明显优于其他两种人工智能算法。  相似文献   

2.
应急救援物资多目标分配和调度集成优化是灾害应急决策中的一个难点问题.为此, 构建一种面向多储备点、多发放点、多种应 急救援物资的并发分配与调度多目标优化模型, 提出一种基于二维NSGA-II与蚁群优化的混合智能搜索算法.在所提算 法中, 设计二维二进制编码、个体修正策略以解决多发放点之间潜在的应急救援物资 冲突, 并改进蚁群优化中的信息素全局更新策略以实现多个调度路径的同时优化.对比实验 结果表明, 所提出的混合算法可以在合理的时间内给出更高质量的应急救援物资分配和调度方案.  相似文献   

3.
为了减少财产损失和人员伤亡、提高灾民满意度,基于双层规划理论,从应急救援角度出发,对突发灾害事件下的应急物资调度问题进行综述。围绕应急物资调度,从灾后应急现状、应急物资选址—分配、不同约束下的应急物资调度及双层规划和群智能优化算法在应急物资调度中的应用等方面进行梳理和讨论。结果表明,关于灾后应急物资调度的研究,目前主要关注单级应急网络结构,且模型的目标函数和约束条件与实际情况存在着出入,结合应急物资调度实际特征提出改进建议;考虑两级应急网络结构,进而构建双层规划模型,实现上下级目标的联合优化。  相似文献   

4.
研究了多供应点、多需求点应急物资调运问题的优化目标、决策模型及求解算法。首先,从需求点的角度考虑应急物资的需求紧迫程度、运达时间和需求满足情况,提出了应急保障综合评价函数。在此基础上,兼顾不同供需情况以及应急物资和运输工具种类的多样性,构建了以应急保障综合评价函数值最小为目标的决策模型。最后,针对模型特点提出了嵌入解构造算法的改进粒子群优化算法(IPSOA-ESCA)。仿真实验验证了应急保障综合评价函数的合理性、模型的普适性和算法的有效性。  相似文献   

5.
徐郁  朱韵攸  刘筱  邓雨婷  廖勇 《计算机应用》2022,42(10):3252-3258
针对现有电力物资车辆路径问题(EVRP)优化时考虑目标函数较为单一、约束不够全面,并且传统求解算法效率不高的问题,提出一种基于深度强化学习(DRL)的电力物资配送多目标路径优化模型和求解算法。首先,充分考虑了电力物资配送区域的加油站分布情况、物资运输车辆的油耗等约束,建立了以电力物资配送路径总长度最短、成本最低、物资需求点满意度最高为目标的多目标电力物资配送模型;其次,设计了一种基于DRL的电力物资配送路径优化算法DRL-EVRP求解所提模型。DRL-EVRP使用改进的指针网络(Ptr-Net)和Q-学习(Q-learning)算法结合的深度Q-网络(DQN)来将累积增量路径长度的负值与满意度之和作为奖励函数。所提算法在进行训练学习后,可直接用于电力物资配送路径规划。仿真实验结果表明,DRL-EVRP求解得到的电力物资配送路径总长度相较于扩展C-W(ECW)节约算法、模拟退火(SA)算法更短,且运算时间在可接受范围内,因此所提算法能更加高效、快速地进行电力物资配送路径优化。  相似文献   

6.
为最大化地发挥应急物流系统的作用,研究面向不同需求,提出构建一个基于改进遗传算法GA的应急物流系统定位-路径优化模型。首先,对遗传算法的基本原理进行具体分析,并在此基础上进行算法改进;然后从需求分级入手,进行模型参数和决策变量确定,构建基于需求分级的应急系统定位-路径优化模型,确定其目标函数和约束条件;之后对模型参数进行求解,获得最优选址和路径方案;最后对改进算法和优化模型进行实验验证。仿真结果表明,改进后的GA算法收敛速度更快,稳定性更好,可用于优化模型中找出最优路径,且构建的优化模型可以很大程度上发挥应急系统的作用,运行成本降低了24.05%、救灾效率显著提高,可在灾害发生时,为应急物流灾害管理人员提供最优路径和救援方案,具有一定的参考意义。  相似文献   

7.
本文对应急物资调度模型的建立及求解该模型的优化算法进行了研究.首先,在资源受限情况下,以配送费用总成本最小和最大缺失损失最小为优化目标,建立了连续消耗问题的多供应点对多受灾点的应急物资调度模型.然后,通过引入DE/best/1变异策略与DE/rand/2变异策略对差分进化算法进行了改进,提出了一种基于双变异策略的改进差分进化算法,将Pareto非支配等级分层与拥挤距离的概念引入到改进差分进化算法中,对约束双目标调度模型进行求解.最后,通过两种不同规模的四组仿真实验,验证了本文提出模型及改进的差分进化算法的可行性和有效性.与基本差分进化算法对比,双变异策略的改进差分进化算法对相同应急物资调度问题进行求解时,得到了更多的Pareto前沿解个数,和较低的应急物资调度配送费用成本与较小的最大缺失损失,同时解分布的广泛性也得到了显著提高.  相似文献   

8.
突发灾难的应急物资的配送有时受多禁止时间约束,为此,针对多禁止时间窗约束的应急物资运输路径优化问题,考虑多禁止时间窗的约束,建立了以总配送时间最小为目标、多禁止时间窗约束的应急物资运输路径优化模型。鉴于该模型为混合整数规划模型,采用GUROBI求解,并与建立的对应的多时间窗约束的路径优化模型对比。最后通过算例分析验证了该模型的高效性和算法的有效性。结果表明,多禁止时间窗约束的应急物资运输路径优化模型求解效率更高;此外评估救灾点对配送时间的影响以及分析多禁止时间窗对应急物资配送规划的影响,结果表明部分救灾点显著影响总配送时间,禁止时间窗的开始时间以及宽度影响总配送路线、时间以及到达各救灾点的时间,因此考虑时间约束特点可为应急物资运输决策提供实用价值。  相似文献   

9.
灾难救援应急物资敏捷配送模型   总被引:1,自引:0,他引:1  
陈刚  张锦  严熹 《计算机工程与应用》2012,48(34):225-229,244
应急物资敏捷配送是灾难救援的重要工作之一,为了给灾区快速配送应急物资,构建了包含救灾物资储备库、应急物资配送中心及受灾点三层结构的应急物资敏捷配送体系。建立相应双层优化模型,其中下层模型决策车辆路径安排,上层模型根据下层模型的结果决策应急物资的分配。根据该模型的特点,提出一种改进蚁群算法求解下层模型,并用CPLEX软件求解上层模型。最后以5·12汶川大地震应急救援为例,对优化模型及求解方法进行了验证。  相似文献   

10.
针对应急物流车辆调度问题中对于经济性、时效性、可靠性和鲁棒性的多种要求,考虑了含有时间窗、不确定需求、不确定行驶时间,以及路段含有失效风险的多目标鲁棒车辆路径优化问题,通过定义新的成本函数、满意度函数、风险度函数和鲁棒度函数作为四个优化目标来构建模型,并基于鲁棒优化理论将不确定模型转化为确定性鲁棒对应模型求解,为解决不确定环境下优化问题提供了新的思路。算法方面,主要基于SPEA2算法框架求解该多目标模型,针对算法缺陷提出多种改进策略,并通过对比实验证明了改进策略的有效性。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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