Children's Reasoning About the Causal Significance of the Temporal Order of Events.

Four experiments examined children's ability to reason about the causal significance of the order in which 2 events occurred (the pressing of buttons on a mechanically operated box). In Study 1, 4-year-olds were unable to make the relevant inferences, whereas 5-year-olds were successful on one version of the task. In Study 2, 3-year-olds were successful on a simplified version of the task in which they were able to observe the events although not their consequences. Study 3 found that older children had difficulties with the original task even when provided with cues to attend to order information. However, 5-year-olds performed successfully in Study 4, in which the causally relevant event was made more salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于EMD的时频熵在齿轮故障诊断中的应用

提出了一种基于EMD(EmpiricalModeDecomposition)方法的时频熵齿轮故障诊断方法。首先利用EMD方法分解齿轮振动信号,然后将得到的内禀模态分量进行Hilbert变换,以得到振动信号的时频分布,将信息熵理论引入时频分布,定量描述时频平面上不同时频段的能量分布,各时频段能量分布的均匀性可以反应齿轮的运行状态的差别,从而可以通过时频熵的大小判断齿轮的工作状态和故障类型。实验证明该方法能有效的判断齿轮故障特征,为齿轮故障诊断提供了新的思路。     

非均匀损伤介质中利用波传播理论对损伤参数的反演

介绍了波在非均匀损伤介质中的传播的反问题,根据波的响应来反演介质的损伤。首先应用Newton迭代法把非线性问题化为线性问题,得到一组不适定的线性方程式组,采用Tikhonov正则化求解,对于正则参数选取采用L线曲线准则,求出了原问题的稳定的、有效的解,获得了与真实损伤度较为吻合的反演参数。工程实例的模拟分析计算证明了上述算法的有效性。     

基于熵的不同工业生产模式环境影响比较研究

从热力学出发，分析了工业生产活动污染环境的熵本质，提出了度量工业生产活动的环境影响非平衡态熵流模型，并分别对三种不同生产模式的熵增值进行计算，得到三种不同生产模式的环境影响趋势，为可持续发展的生产模式的选择提供依据。     

热冷轧订单追踪系统设计与实现

热冷轧订单追踪管理系统是武钢整体产销资讯系统中比较重要的子系统之一。掌控生产订单整个生产过程中的执行状况。整个系统以生产订单为中心,准确掌握生产订单的执行状况,动态掌握各工序间实物量流动情况,按订单准确计算待炼钢申请量并以此提出炼钢浇次计划,对无主板坯自动适配订单。     

钢铁企业信息化新技术(上)

叙述了钢铁企业信息化的目标、任务和四级功能结构,重点阐述了产销一体化系统ISPS和钢铁企业信息化的六类关键技术。     

DVD租赁优化方案

在线租赁是信息时代发展的必然趋势。在租赁过程中，网络经营者主要关注DVD的预测、购买和分配。本文提出了简单随机抽样、分类预测和关联预测等三种方法进行需求预测。针对问题一，利用需求预测得到观霜DVD的人数服从二项分布，并计算出多种可靠度下购买DVD的数量。以会员的最大满意度为目标函数，建立一个整数规划模型，得到问题二的分配方案。并计算出前30位会员的分配结果。在问题三中，我们考虑到60％的会员由于两次租赁而导致DVD可重复利用，因而，采用了两阶段购买的策略，在每个购买阶段都建立了双目标整数规划，从而得到的购买量比原来网站拥有量小，并且会员的满意度达到99．38％，本文最后还给出了考虑归还DVD周期的情形下购买与分配的模型。     

High‐order Higdon‐like boundary conditions for exterior transient wave problems

Recently developed non‐reflecting boundary conditions are applied for exterior time‐dependent wave problems in unbounded domains. The linear time‐dependent wave equation, with or without a dispersive term, is considered in an infinite domain. The infinite domain is truncated via an artificial boundary ??, and a high‐order non‐reflecting boundary condition (NRBC) is imposed on ??. Then the problem is solved numerically in the finite domain bounded by ??. The new boundary scheme is based on a reformulation of the sequence of NRBCs proposed by Higdon. We consider here two reformulations: one that involves high‐order derivatives with a special discretization scheme, and another that does not involve any high derivatives beyond second order. The latter formulation is made possible by introducing special auxiliary variables on ??. In both formulations the new NRBCs can easily be used up to any desired order. They can be incorporated in a finite element or a finite difference scheme; in the present paper the latter is used. In contrast to previous papers using similar formulations, here the method is applied to a fully exterior two‐dimensional problem, with a rectangular boundary. Numerical examples in infinite domains are used to demonstrate the performance and advantages of the new method. In the auxiliary‐variable formulation long‐time corner instability is observed, that requires special treatment of the corners (not addressed in this paper). No such difficulties arise in the high‐derivative formulation. Published in 2005 by John Wiley & Sons, Ltd.     

An elliptical disc anchor in a damage‐susceptible poroelastic medium

A flat rigid elliptical anchorage located in a damage‐susceptible fluid‐saturated poroelastic medium is subjected to an in‐plane load, which induces a pure translation in the plane of the anchor. This paper develops computational estimates for the time‐dependent displacement of the disc anchor for the classical problem that involves Biot consolidation and compares the results with situations where the porous skeleton can experience micro‐mechanical damage that leads to an alteration in both its elasticity and fluid transport characteristics. Copyright © 2005 John Wiley & Sons, Ltd.     

关于一个Bernstein型插值过程收敛阶的点态估计

研究了Bernstein插值多项式Pn(f;x)对f(z)∈C[-1,1]j(0≤j≤1)连续函数类的逼近阶，在连续状态下给出了点态的逼近阶。