混凝土构件裂缝宽度计算方法的探讨

混凝土构件裂缝宽度的计算复杂、难度大,国内外学者都投入了大量的精力来研究其计算方法,多年来发展了很多计算理论。主要介绍国内除混凝土规范运用的方法之外的几种典型计算理论。通过对国内研究方法的探讨,可知运用半经验半理论方法计算裂缝宽度尚有一定的不足,仍需进一步改进。     

On Covering Radius and Discrete Chebyshev Polynomials

 We derive a new upper bound on the covering radius of a code as a function of its dual distance. This bound improves on the Honkala-Litsyn-Tiet?v?inen bound and in a certain interval it is also better than Tiet?v?inen’s bound. Upper bounds on even-weight codes are considered as well. Received: November 4, 1996; revised version: February 1, 1997     

灰色关联分析法及其在膨胀土等级判定中的应用

本文提出用灰色关联分析法和灰色权距分析法来判定膨胀土的胀缩等级．并与模糊判定法、灰色聚类法的计算结果进行对比．说明灰色关联法和灰色权距法应用效果较好。     

Subpixel position measurement using 1D, 2D and 3D centroid algorithms with emphasis on applications in confocal microscopy

The accuracy with which centroid algorithms in 1D, 2D and 3D can estimate an object's position has been investigated. Three factors that can influence the method's accuracy have been investigated: systematic error of the algorithm, influence of photon noise and the influence of perturbations such as scanning nonlinearity. The variation of the accuracy with parameters that are relevant for confocal microscopy, such as object diameter and photon noise/pixel, has been considered. Theory and simulations presented show that the variation of the accuracy with respect to such parameters can differ drastically between the 1D, 2D and 3D cases. Experiments performed using microspheres show that the magnitudes of the three types of error can be approximately the same under normal operating conditions and that it is therefore necessary to take all three into account when assessing the total error.     

基于移动Agent的远程教学系统研究

目前的远程教学系统普遍存在智能性差、个性化不突出、交互性手段匮乏等问题。为此把移动Agent技术应用于远程教学系统，提高远程教学系统的智能化和个性化程度，以便充分挖掘学习者的潜力，改善教学效果。     

A fast and simple algorithm for computing the longest common subsequence of run-length encoded strings

Let X and Y be two strings of lengths n and m, respectively, and k and l, respectively, be the numbers of runs in their corresponding run-length encoded forms. We propose a simple algorithm for computing the longest common subsequence of two given strings X and Y in O(kl+min{p₁,p₂}) time, where p₁ and p₂ denote the numbers of elements in the bottom and right boundaries of the matched blocks, respectively. It improves the previously known time bound O(min{nl,km}) and outperforms the time bounds O(kllogkl) or O((k+l+q)log(k+l+q)) for some cases, where q denotes the number of matched blocks.     

k-Diameter of Circulant Graph with Degree 3

Parameters k-distance and k-diameter are extension of the distance and the diameter in graph theory. In this paper, the k-distance dk （x,y） between the any vertices x and y is first obtained in a connected circulant graph G with order n （n is even） and degree 3 by removing some vertices from the neighbour set of the x. Then, the k-diameters of the connected circulant graphs with order n and degree 3 are given by using the k-diameter dk （x,y）.     

基于单片机的超声波测距系统的设计

介绍了利用单片机控制的超声波测距系统的原理，由单片机控制时间计数、控制超声波的发射和接收。给出了系统构成，并在数据处理中采用了温度补偿修正。此系统具有易控制、工作可靠、测量精度高的优点。     

晶体生长的边界层效应—兼论光学实时观察法晶体生长技术

晶体生长边界层模型起源于流体动力学边界层模型，但两者又不完全相同，晶全生长边界层模型有两方面的含义：（１）在固－液界面处的、垂直于界面的，由杂质和组份构成的质量流决定晶体生长速度；（２）在界面附加溶度一侧的质量浓度流，其浓度分布是决定界面稳定性的基本参数。