求解带硬时间窗的多目标车辆路径问题的多种混合蝙蝠算法

针对多目标车辆路径问题的研究,考虑了车载量限制和硬时间窗的约束条件,以最小派车数和最小车辆行驶距离为目标建立了数学模型。在分析基本蝙蝠算法求解离散问题局限性的基础上,混合蝙蝠法加入交叉算子和重组算子,提高算法性能。利用遗传算法的特点,构建出三种混合蝙蝠算法,算例测试结果表明,混合蝙蝠算法是解决离散型问题的一种有效方法。与基本蝙蝠算法相比,混合蝙蝠算法具有较高的计算效率和持续优化能力,其中单点重组精英遗传混合蝙蝠算法解决算例寻优能力最佳。 关键词：混合蝙蝠算法;车辆路径问题;多目标;硬时间窗     

基于速度越界处理与最速下降法改进的蝙蝠算法

针对蝙蝠算法(Bat algorithm,BA)易陷入局部极值、精度不高、搜索盲目性大的缺点,在分析蝙蝠算法本身的迭代机制的基础上,提出一种基于速度越界处理与最速下降法改进的蝙蝠算法(VCBA)。利用速度的越界处理控制蝙蝠位置更新的范围;利用最速下降法对BA局部搜索阶段中不好的蝙蝠位置进行更新;对位置较好的蝙蝠在其附近进行扰动;对BA判断局部搜索阶段产生的蝙蝠位置是否满足需求的条件进行改进。选取7个测试问题进行数值实验,结果表明,VCBA在收敛精度和稳定性上比BA有显著提升。     

基于蝙蝠拟牛顿混合算法的无线传感器网络节点定位

针对距离矢量-跳数(DV-Hop)算法第三阶段中最小二乘法定位精度低的问题,提出一种蝙蝠-拟牛顿混合算法与DV-Hop算法融合的定位算法.首先对蝙蝠算法进行两点改进:1)根据蝙蝠个体的适应度值自适应调节随机向量β,使得脉冲频率具有自适应能力;2)利用当前迭代之前所有最优个体的平均位置来引导蝙蝠移动,使得速度具有变异性能;然后在DV-Hop算法第三阶段采用改进蝙蝠算法得出节点的估计位置,再利用拟牛顿算法以估计位置为初始点继续搜索节点位置.仿真结果表明:相比传统DV-Hop算法和基于蝙蝠算法的DV-Hop改进算法(BADV-Hop),该算法的定位精度大约提高了16.5%、5.18%,且稳定性更好,适用于定位精度和稳定性要求较高的场合.     

求解高维函数优化问题的交叉熵蝙蝠算法

为改善蝙蝠算法求解高维函数优化问题的全局搜索能力,提高其搜索精度,将交叉熵方法和蝙蝠算法相结合,提出一种交叉熵蝙蝠算法。该算法将基于重要度抽样和Kullback-Leibler距离的交叉熵全局随机优化算法应用于蝙蝠算法中,采用自适应平滑技术提高算法的收敛速度,利用交叉熵方法的遍历性、自适应性和鲁棒性,有效抑制蝙蝠算法的早熟收敛现象。对经典测试函数和CEC2005测试函数的仿真结果表明,该算法具有全局搜索能力强、求解精度高和鲁棒性好等特性。     

基于改进蝙蝠算法和三次样条插值的机器人路径规划

为更好地解决移动机器人路径规划问题, 改进蝙蝠算法的寻优性能, 拓展其应用领域, 提出了一种具有反向学习和正切随机探索机制的蝙蝠算法. 在全局搜索阶段的位置更新中引入动态扰动系数, 提高算法全局搜索能力; 在局部搜索阶段, 融入正切随机探索机制, 增强算法局部寻优的策略性, 避免算法陷入局部极值. 同时, 加入反向学习选择策略, 进一步平衡蝙蝠种群多样性和算法局部开采能力, 提高算法的收敛精度. 然后, 把改进算法与三次样条插值方法相结合去求解机器人全局路径规划问题, 定义了基于路径结点的编码方式, 构造了绕避障碍求解最短路径的方法和适应度函数. 最后, 在简单和复杂障碍环境下分别对单机器人和多机器人系统进行了路径规划对比实验. 实验结果表明, 改进后算法无论在最优解还是平均解方面都要优于其他几种对比算法, 对于求解机器人全局路径规划问题具有较好的可行性和有效性.     

一种高效的混合蝙蝠算法

针对基本蝙蝠算法存在收敛速度慢,易陷入局部最优,求解精度低等缺陷,提出一种融合局部搜索的混合蝙蝠算法用于求解无约束优化问题。该算法利用混沌序列对蝙蝠的位置和速度进行初始化,为全局搜索的多样性奠定基础;融合Powell搜索以增强算法的局部搜索能力,加快收敛速度;使用变异策略在一定程度上避免算法陷入局部最优。选取几个标准测试函数进行仿真实验,结果表明：与基本蝙蝠算法和粒子群优化算法相比,混合蝙蝠算法具有更好的寻优性能。     

基于栅格环境搜索树的配送路径局部规划北大核心CSCD

为提高配送路径规划算法的有效性,提出一种基于栅格环境Morphin搜索树的配送局部路径规划算法。首先,根据配送城市路况复杂性,利用动力学轨迹模型对配送路径进行建模,模拟配送过程的车辆行驶状态,并给出车辆运行饱和时间指标判别方法;其次,引入Morphin搜索树算法对配送路径的动力学轨迹模型进行优化搜索,同时为提高模型优化精度,提出一种基于栅格环境的Morphin搜索树改进方法,有助于降低路径规划中障碍物碰撞问题;最后,通过在SUMO和OMNET平台上仿真实验,显示所提路径规划算法具有更佳的车辆滞留控制和更低的碳排放效果,验证了算法的有效性。     

集货需求模糊的异型车同时配集货路径优化

针对集货需求模糊的异型车同时配集货车辆路径问题(HFVRPSDDFP),基于先预优化再重优化的思路构建模型.预优化阶段根据可信度理论和车型选取方法为客户点分配车辆,生成配送方案.重优化阶段利用随机模拟算法(SSA)确定客户集货需求,对服务失败的客户点,制定服务策略,将模糊问题转化为确定型的异型车辆路径问题(HFVRP),并规划路径.设计遗传变邻域算法,通过测试确定邻域结构构造,将自适应搜索策略应用到邻域搜索过程中,保证迭代前期收敛速度和后期全局搜索能力.通过算例验证了本文模型及算法的有效性.     

求解带容量约束车辆路径问题的离散鲸鱼算法

论文提出了一种离散鲸鱼算法求解带容量约束的车辆路径问题(Capacitated Vehicle Routing Problem).该算法对基本鲸鱼算法的包围捕食操作、泡泡网捕食操作、随机捕食操作进行重定义,并采用基于距离代价的K-means算法在满足车辆最大载重约束条件下将客户划分到不同区域.并引入随机交换搜索、2-opt、3-opt优化方法对每次迭代过程中得到的最优解进行局部优化,扩大算法搜索空间算法.实验结果表明:所提算法能够有效解决带容量约束车辆路径问题,有较强的寻优能力,求解质量优于所对比算法.     

绝对值方程的交叉熵蝙蝠算法求解

针对绝对值方程这一NP-难问题和其转换为无约束优化问题具有不可微的特点,一种交叉熵蝙蝠算法被构建.该算法将基于方差最小化、重要性抽样和Kullback-Leibler距离的交叉熵随机优化算法嵌入到基于仿生学的蝙蝠算法中,充分发挥交叉熵方法的随机性、自适应性和鲁棒性,有效抑制蝙蝠算法的早熟收敛现象,提高优化性能.数值结果表明,新算法具有全局搜索能力强、计算精度高和数值稳定性好等特点,也适用于高维绝对值方程问题.     

Only connect: teaching, technology and telesis

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.     

European Community policy and the market

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.     

一种自适应子融合集成多分类器方法

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。     

Avoiding semantic and temporal gaps in developing software intensive systems

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.     

Designing economic np control charts: A programmed simulation approach

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.     

The development of robot art

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     

Explanation and prediction: an architecture for default and abductive reasoning

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.     

Three Process Perspectives: Organizations, Teams, and People

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.     

基于复小波噪声方差显著修正的SAR图像去噪

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。     

How do children do mathematics with LOGO?

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.