“波的形成与传播”演示实验的质疑与改进

质疑"波的形成与传播"一节中的传统演示实验及改进"人浪"演示实验.     

对称熵损失下BurrⅫ分布族形状参数和失效率函数的Bayes估计

基于逐次定数截尾样本,在对称熵损失下,针对不同的先验分布,讨论BurrXII分布的形状参数和失效率函数的Bayes估计。对先验分布中所含的超参数采用减函数法构造其先验分布,从而得到相应的Bayes估计。文中说明了所得到的估计是可容许的,文尾运用Monte Carlo方法对估计量的MSE进行了模拟比较。结果显示,所得到的估计有较高的精度。     

平衡指数损失函数下的信度保费

在经典的信度保费模型中,得到的信度保费估计均是考虑的是纯保费,然而在保险实务中,保险公司收取的保费不可能是纯保费,必须具有正的安全负荷.在平衡指数损失函数下,研究了多合同的信度保费模型.利用正交投影方法,得到了未来保费的信度估计.最后对估计进行了数值模拟.     

Efficient statistical inference for partially nonlinear errors-in-variables models

In this paper, we consider the partially nonlinear errors-in-variables models when the non- parametric component is measured with additive error. The profile nonlinear least squares estimator of unknown parameter and the estimator of nonparametric component are constructed, and their asymptotic properties are derived under general assumptions. Finite sample performances of the proposed statistical inference procedures are illustrated by Monte Carlo simulation studies.     

基于剪枝信任度传播的手写体目标形状匹配方法

手写体识别中,目标形状的匹配是较为重要的工作.为了提高手写体目标形状的匹配速度,提出一种新的匹配方法.由于手写体目标形状的几何先验知识已知,并可以采用少量的参数进行表示,新方法采用参数化可变形模板匹配目标形状,确定其后验概率模型,并定义剪枝信任度空间,依据信任度传播算法的特性,首次将剪枝信任度传播算法应用于求解可变形模板与目标形状之间的最佳匹配.实验结果显示,在灰度图像中,对手写体目标形状的轮廓检测与定位速度显著提高.提出将剪枝信任度传播方法应用于手写体目标形状的匹配工作,能够使得目标形状填补空白,应用于相关性较为稀疏的图模型中.     

基于时间序列与灰色拓扑的春节火灾损失预测

火灾每年给中国带来了巨大的损失,春节期间的火灾损失更是严重.根据1999-2010年春节期间火灾统计资料,火灾四项指标数据具有时序性以及随机波动性、模糊性.运用时间序列与灰色拓扑预测方法相结合预测春节期间火灾发生规律,且预测出未来3年内的火灾发生情况.结果表明,时间序列预测模型的平均绝对误差较小,且所建立的灰色拓扑预测模型的拟合精度都达到"好"的标准.因此,采用时间序列与灰色拓扑预测模型相结合对春节火灾发生情况进行预测,其结果合理可靠,可供理论研究和消防部门做出相应的预防措施参考,以达到有效控制和预防春节火灾的目的.     

面向客户需求的企业集群知识传播模型与仿真

本文从市场中客户对企业提出的各种需求出发,建立了一个面向客户需求的知识传播网络,并通过计算机仿真模拟了企业集群在此网络中的知识传播过程,考察了集群的平均知识水平和知识方差在传播过程中的动态变化。通过仿真发现:随着时间的推移和对客户需求的满足,集群的平均知识水平呈单调递增趋势,知识传播效率呈现先增后减规律;集群知识方差在传播前期会出现剧烈震荡现象,而后期则会逐渐收敛;此外本文对市场规模以及知识维度对知识水平的影响也做了简单的考察,发现小规模市场有利于企业集群的初期发展,而过高或过低的知识维度都不利于企业集群平均知识水平的提高。     

木马病毒传播数学模型研究

随着网络行为同社会行为联系的进一步密切,网络攻击的最终目的越来越多地落在获取具体的经济意义上.病毒制造者和传播者在巨大利益的驱使下,利用木马技术进行各种网络盗窃、诈骗活动.计算机网络病毒传播模型是研究计算机网络病毒的手段和工具之一,根据木马病毒的特点,建立了木马病毒的数学模型,研究了影响病毒传播的参数及对应措施.     

General admissibility for linear estimators in a general multivariate linear model under balanced loss function

A generalization of Zellner’s balanced loss function is proposed. General admissibility in a general multivariate linear model is investigated under the generalized balanced loss function. And the sufficient and necessary conditions for linear estimators to be generally admissible in classes of homogeneous and nonhomogeneous linear estimators are given, respectively.     

Analysis on absolute measurement of optical coating absorption loss based on photothermal detuning technique

Based on the photothermal detuning technique, the three linear relations among reflectance （or trans- mittance）, temperature rise, and pump beam power are studied to achieve the absolute measurement of absorption loss. The relation between temperature and reflectance and the calculation accuracy of tem- perature rise on sample surface have great impacts on the measured result. The influences of parameters involved in the method and the relation between temperature and reflectance and the temperature model of sample surface are also studied. The results show that the absolute absorption loss of optical coatings can be achieved by the proposed method. The measurement accuracy depends on the temperature model and the relation between temperature and reflectance. The linear relation between reflectance and temper- ature rise has largest slope when probe beam wavelength is 632.8 nm and incident angle is 28°. The linear relation slope between temperature rise and pump beam power decreases with the growing of beam size and modulation frequency. The results provide theoretical and experimental supports for the perfection and further application of the photothermal detuning technique.