悬挂特性参数对履带车辆随机路面越野平顺性能影响

研究履带车辆悬挂系统参数对履带车辆最高越野时速的影响.建立了多轮车辆的线性2自由度模型(垂直及俯仰),以不同路面等级的随机路面作为模型输入,对不同悬挂刚度、车辆速度及悬挂阻尼的模型进行仿真计算.结果表明,提高悬挂的动行程和减振器的散热能力能够显著提高履带式装甲车辆的最高越野时速.     

包容核废物的钛酸锶人造岩石SHS-致密化的影响因素

采用自蔓延高温合成(SHS)与加压致密一体化技术制备了包容锶核素(Sr2+)的钛酸锶(SrTiO3)人造岩石固化体. 通过实验分析SHS产物致密化的影响因素,确定了钛酸锶反应体系自蔓延高温合成时的最佳工艺参数:预制块相对密度为54%左右;预压力为10MPa,加压时间为4s;致密化时高压压力为300MPa,高压保压时间为8s.     

混凝土材料声发射技术研究

总结了混凝土材料声发射技术研究的历史及现状,对混凝土材料声发射机理、声发射参数与力学参数间的关系、声发射在断裂力学中的应用、混凝土材料的凯塞效应以及新的理论与方法在声发射领域的应用等问题进行了评价与展望.     

基于区间参数摄动法的黏弹性区间有限元研究

对线性静力区间有限元应力区间计算方法进行了评述,认为将含有区间参数的高斯点应力在区间参数均值处进行Taylor展开,计算得到的应力区间扩张不明显.将区间分析方法应用于黏弹性问题分析,推导了黏弹性问题的区间参数摄动法计算公式,研制了相应的黏弹性区间有限元计算程序.通过算例分析认为:采用区间参数摄动法进行黏弹性问题分析是可行的;随着位移均值的增加,位移离差也逐渐增大;位移区间最终随着位移均值的稳定而逐渐趋于稳定.     

灰色GM(1,1)模型建模的理论探讨

在分析GM(1,1)建模中灰导数及其白化背景值对模型精度与适应性的影响的基础上,从灰导数、灰导数的白化背景值的构造证明了原始时间序列数据变化越平缓,发展系数的绝对值越小,GM(1,1)模型的拟合与预测精度越高,模型的适应性越强,同时提出了原始序列数据的一些处理方法。     

五次Bézier曲线的三种不同扩展

三组含有参数λ的六次多项式基函数是五次Bernstein基函数的扩展;基于此三组基分别定义了带有形状参数的三类多项式曲线;三类曲线不仅具有五次Bézier曲线的特性,而且具有形状的可调性和更好的逼近性;在一组基的基础上利用的de Casteljau算法,得到n+1次n+1个带有参数λ的的基函数,并定义了相应的n+1次曲线。应用实例表明,本文定义的曲线应用于曲线曲面的设计十分有效。     

基于广义八面体理论的岩土参数c、Ф间接求法

在真三轴应力状态下,根据岩土剪切破坏面的倾角不同,采用不同的剪切破坏面对正六面单元体进行不断地截取,所得到的一系列连续八面体,即广义八面体。由于正交八面体应力空间可以反映主应力、双剪应力和静水应力,因此可以利用这三种应力成分建立起反映连续八面体应力空间的多项式强度模型,并利用单轴特征试验点和平面4个特征试验点,得到了内摩擦角和黏聚力参数方程。同时,利用线性方程组非满秩的物理意义,建立了多轴特征强度参数关系方程。这些参数方程不仅表明了多轴强度与单轴强度的关系,而且还可以利用其计算所缺失的特征强度,从而可简化岩土参数的测定方法。     

两Gamma总体尺度参数的最佳双边似然比检验

对于两个相互独立且来自不同Gamma总体的样本,在形状参数已知的情况下推导出其尺度参数齐性检验问题的似然比统计量.在犯第二类错误累积概率最小的意义下,推导出其最佳检验的临界值条件,并证明了最佳检验的存在唯一性,并给出了显著性水平为0.05时,样本容量从(2,2)到(20,20)的最佳检验的临界值表.     

A DNA sequence alignment algorithm using quality information and a fuzzy inference method

DNA sequence alignment algorithms in computational molecular biology have been improved by diverse methods. In this paper, we propose a DNA sequence alignment that uses quality information and a fuzzy inference method developed based on characteristics of DNA fragments and a fuzzy logic system in order to improve conventional DNA sequence alignment methods that uses DNA sequence quality information. In conventional algorithms, DNA sequence alignment scores are calculated by the global sequence alignment algorithm proposed by Needleman-Wunsch, which is established by using quality information of each DNA fragment. However, there may be errors in the process of calculating DNA sequence alignment scores when the quality of DNA fragment tips is low, because only overall DNA sequence quality information are used. In our proposed method, an exact DNA sequence alignment can be achieved in spite of low quality of DNA fragment tips by improvement of conventional algorithms using quality information. Mapping score parameters used to calculate DNA sequence alignment scores are dynamically adjusted by the fuzzy logic system utilizing lengths of DNA fragments and frequencies of low quality DNA bases in the fragments. From the experiments by applying real genome data of National Center for Biotechnology Information, we could see that the proposed method is more efficient than conventional algorithms.     

DNA media storage

In 1994, University of Southern California computer scientist Dr. Leonard Adleman solved the Hamiltonian path problem using DNA as a computational mechanism. He proved the principle that DNA computing could be used to solve computationally complex problems. Because of the limitations in discovery time, resource requirements, and sequence mismatches, DNA computing has not yet become a commonly accepted practice. However, advancements are continually being discovered that are evolving the field of DNA computing. Practical applications of DNA are not restricted to computation alone. This research presents a novel approach in which DNA could be used as a means of storing files. Through the use of multiple sequence alignment combined with intelligent heuristics, the most probabilistic file contents can be determined with minimal errors.