KHV内啮合副优化问题的超越方程组求解法

对于KHV内啮合副(即渐开线少齿差内啮合行星齿轮副)可行解的寻求，在未采用电算技术的情况下已属较为复杂的工程计算。借助于电算技术，不仅可很方便地求得其可行解，且可进一步寻求其优化解。本文介绍的KHV内合副优化设计的方法，是通过对超越方程组的求解而进行的，它具有迭代次数少、占用内存少、程序简单、收敛快的特点，因此可在微处理机上进行该啮合副主要几何参数(包括齿形系数)的优化设计。本文介绍的程序，可做为独立的KHV内啮合副优化程序，从而获得具有标准径向间隙的啮合副优化参数，也可以作为非标准径向间隙的啮合副优化设计中，求对应于某一c*(或ha*)值的最优参数的子程序。本文蓝对按照最小啮合角原则设计少齿差内啮合副的经济效益作了粗略的估计。     

Integrated semantic similarity model based on ontology

To solve the problem of the inadequacy of semantic processing in the intelligent question answering system. an integrated semantic similarity model which calculates the semantic similarity using the geometric distance and informarion content is presented in this paper. With the help of interrelationship between concepts, the information content ofconcepts and the strength of the edges in the ontology network. we can calculate the semantic similarity between two concepts and provide information for the further calculation of the semantic similarity between user‘s question and answers in knowlegdge base. The results of the experiments on the prototype have shown that the semantic problem in natural language processing can also be solved with the help of the knowledge and the abundant semantic information in ontology. More than 90% accuracy with less than 50 ms average searching time in the intelligent question answering prototype system based on ontology has been reached. The result is vety satisfied.     

Empirical study on mutual fund objective classification

Mutual funds are usually classified on the basis of their objectives. If the activities of mutual funds are consistent with their stated objectives, investors may look at the latter as signals of their risks and incomes. This work analyzes mutual fund objective classification in China by statistical methods of distance analysis and discriminant analysis; and examines whether the stated investment objectives of mutual funds adequately represent their attributes to investors. That is, if mutual funds adhere to their stated objectives, attributes must be heterogeneous between investment objective groups and homogeneous within them. Our conclusion is to some degree, the group of optimized exponential funds is heterogeneous to other groups. As a whole, there exist no significant differences between different objective groups; and 50% of mutual funds are not consistent with their objective groups.     

Study on properties of residue-residue contacts in protein

Residue-residue contacts are very important in forming protein structure. In this work, we calculated the average probability of residue-residue contacts in 470 globular proteins and analyzed the distribution of contacts in the different interval of residues using Contacts of Structural Units (CSU) and Structural Classification (SCOP) software. It was found that the relationship between the average probability PL and the residue distance L for four structural classes of proteins could be expressed as lgPL=a+b x L, where a and b are coefficients. We also discussed the connection between two aspects of proteins which have equal array residue number and found that the distribution probability was stable (or un-stable) if the proteins had the same (or different) compact (for example synthase) in the same structural class.     

空间对桉树（刚果12号W5）树体养分质量含量的影响

为了探讨树体养分(N、P、K)的质量含量是否受空间距离的影响,以便为林地养分管理和种植密度的选择提供理论依据.本试验研究了2种空间距离(株行距1.5 m×2.5 m和1.5 m×5.0 m)下桉树(刚果12号W5无性系)单株树木的生长和树体各器官N、P、K质量含量的变化规律.结果表明随着空间距离增大了一倍,胸径、高和生物量明显增加;除了叶部P、K和皮部K外,其他树体器官的N、P、K质量含量均有所增加;在树体养分N、P、K的平均质量含量中,N的质量含量增加值最大,且这种增加值主要来自干部的质量含量;空间距离对N、P养分的质量含量的影响较大.因此认为合理确定种植密度对林地养分管理具有重要的理论和实践意义.     

基于高分辨雷达的运动目标参数估计方法研究

根据运动目标的频域回波的特点，深入研究了一种具有多项式相位结构的运动目标回波仿真模型，并提出了基于该模型的多特征参数提取方法。该方法基于匹配傅立叶变换理论，依据频域雷达目标回波特征构造匹配函数，对目标回波数据进行匹配傅立叶变换，变换结果的主瓣坐标反映了目标散射点的距离及速度信息。大量的仿真实验结果证明，该方法十分有利于进行运动目标的特征提取。根据对仿真结果的分析，进一步给出了改进算法，使得在较低信噪比情况下也能够有效的检测出目标上的散射点的距离与速度参数。     

Vague集距离的比较与改进

回顾了vague集已有的距离定义,通过例子说明现有的距离定义在有些情况不适用,并且分析了现有vague集距离定义的不足,充分利用vague集的本质含义,给出了vague集之间距离的新定义,分析证明了所给vague集的距离定义与现有距离定义之间的关系,最后通过例子说明了新方法的合理性与有效性.     

作物遭受雹灾咋补救?

棉花棉花具有很强的生理补偿作用和再生能力,遭受雹灾后,只要加强管理,仍能获得较好收成,不要轻易翻种.①中耕松土.及早进行中耕、晾墒,以增温通气,控制死苗,促进早发;特别是盐碱地棉田,更应及时松土,防止返盐死苗.②追施速效氮肥.一般地块,每亩可追施尿素5～7.5千克或碳铵13～15千克.追肥时,肥料要距离棉株10～13厘米,以防烧根.③及时治虫.棉株受灾后萌发的枝叶较为幼嫩,前期蚜虫多,后期易受棉铃虫、棉小造桥虫等危害,要早治、狠治,做到每叶必保,每蕾(铃)必争.必要时,可在棉株萌芽初期喷药防治蚜虫.④科学整枝.     

求解Hamming距离下单位型单发点树型网络最短路改进问题的算法

给出了求解两类特殊的Hamming距离下单位型单发点树型网络最短路改进问题的多项式时间算法,并研究了一般树型网络下该问题的性质.解决了Hamming距离下逆问题(改进问题)中的部分问题,有助于设计出更多的求解Hamming距离下单位型树型网络最短路改进问题的算法.     

树图及其顶点数的计算

文章从生成树之间的距离出发,定义了连通图的树图概念并证明了若干个简单性质,然后根据基本关联矩阵的性质,讨论了用行列式计算给定连通图的树图的顶点数。