城市区域多物流无人机协同任务分配

针对城市区域多无人机协同物流任务分配问题, 综合考虑不同无人机性能、物流时效性、飞行可靠性等影响因素, 以经济成本、时间损失和安全风险最小为目标函数, 构建多无人机协同物流任务分配模型。因问题规模大、求解复杂度高, 设计改进的量子粒子群算法进行求解。首先，为增强粒子遍历性和多样性, 采用均匀化级联Logistic映射进行粒子初始化; 其次，为避免算法陷入局部最优解, 引入基于高斯分布的粒子变异方式; 最后，为提高算法运行效率, 运用自适应惯性权重方法对粒子赋值。仿真实验结果表明，所构建的模型能够实现任务分配多目标优化, 贴近城市区域无人机物流配送实际; 所提算法与传统量子粒子群算法和遗传算法相比, 任务分配代价分别下降了5.9%和6.3%;并进一步对参数权重设置进行分析, 当3个子目标函数权重系数分别为0.225、0.275和0.500, 种群规模为150时, 算法规划的结果最优。     

Local reduction in physics

A conventional wisdom about the progress of physics holds that successive theories wholly encompass the domains of their predecessors through a process that is often called “reduction.” While certain influential accounts of inter-theory reduction in physics take reduction to require a single “global” derivation of one theory׳s laws from those of another, I show that global reductions are not available in all cases where the conventional wisdom requires reduction to hold. However, I argue that a weaker “local” form of reduction, which defines reduction between theories in terms of a more fundamental notion of reduction between models of a single fixed system, is available in such cases and moreover suffices to uphold the conventional wisdom. To illustrate the sort of fixed-system, inter-model reduction that grounds inter-theoretic reduction on this picture, I specialize to a particular class of cases in which both models are dynamical systems. I show that reduction in these cases is underwritten by a mathematical relationship that follows a certain liberalized construal of Nagel/Schaffner reduction, and support this claim with several examples. Moreover, I show that this broadly Nagelian analysis of inter-model reduction encompasses several cases that are sometimes cited as instances of the “physicist׳s” limit-based notion of reduction.     

基于高斯字典原子稀疏表示的高精度宽角SAR成像方法

为了提高从宽角合成孔径雷达(synthetic aperture radar, SAR)图像中提取目标后向散射各向异性特性的性能,在宽角SAR字典稀疏表示模型的基础上,提出一种基于高斯字典原子的高精度宽角SAR成像方法。在字典构造上,采用不同中心位置、相同方差的高斯函数。在求解稀疏表示系数上,采用广义最小最大凹惩罚稀疏重构算法求解。最后，根据稀疏表示系数的重构结果以及构造的字典得到目标的后向散射各向异性特性。通过仿真实验和Backhoe数据对算法进行验证,结果表明,该方法能够高精度地提取目标的后向散射各向异性特性。     

关于一类Hankel算子的截断性与有界性

本文研究了在两个 Moebius 不变子空间 A_l~(a,2)(D)与 A_l~(a,2)(D)之间的、由双线性形式定义的一类 Hankel 算子的截断(cut-off)性质与有界性质,从而发展了这一算子的 Schatten—von Neumann 性质。     

油田水CaCO_3结垢反应的计算与应用

以热力学计算为基础，广泛采用油田水的数据．计算了ＣａＣＯ３的预测条件，并根据油田生产实际，建立了使用防垢剂时的预测模型．根据理论模型编制成计算机程序，并与文献结果和油田观测结果进行了对比，提出了临界浓度和临界稳定常数的计算和应用方法．为防垢剂的选择提供了理论依据，大量计算表明，预测结果与文献和现场观测结果相符．     

A latent class probit model for analyzing pick any/N data

A latent class probit model is developed in which it is assumed that the binary data of a particular subject follow a finite mixture of multivariate Bermoulli distributions. An EM algorithm for fitting the model is described and a Monte Carlo procedure for testing the number of latent classes that is required for adequately describing the data is discussed. In the final section, an application of the latent class probit model to some intended purchase data for residential telecommunication devices is reported. Geert De Soete is supported as “Bevoegdverklaard Navorser” of the Belgian “Nationaal Fonds voor Wetenschappelijk Onderzoek.”     

高斯光束通过离焦望远镜系统的变换

文章应用复参数表示和ABCD定律,讨论高斯光束通过离焦望远镜系统的变换问题,其结论对实际操作有指导意义。     

样本函数条件极值的渐近性质

讨论了形如ψ(x,Gnk(x|y))的样本函数极值特性,其中Gnk(x|y)是G(x|y)第k个最近邻域(k-NN) 的估计,得出在常规条件下存在某一Gaussian过程,使得收敛于这一Gaussian过程。     

高斯光束的反向传输变换

用高斯光束的复数表示和ＡＢＣＤ定律,讨论了高斯光束的反向传输变换,并求出了表述高斯光束的几个重要参量。     

谐振腔镜对高斯光束远场发散角的影响

利用变换矩阵和ＡＢＣＤ定律讨论了激光谐振空对高我束的变换,推导出高斯光束参数通过光腔输出镜的变换公式。并对热透镜腔,光束远场发散角等问题进行了讨论。