A method to quantitatively estimate rainfall rate above water surface based on different spectra shapes generated by rainfall

A method combined with the nonlinear least-square regression to quantitatively estimate rainfall rate over water surface from the different spectrum shapes generated by rainfall in some frequency bands was presented.About 2000 min spectrum data generated by rainfall have been collected in an open-lake in Xiamen city.As a result,the spectrum shape in 15-30 kHz is fitted to log-linear law which allows classification of rain into three categories from the spectrum slope:no rain,drizzle(rainfall rate>10 mm/h)and heavy rain(rainfall rate>10 mm/h).Then,rainfall detection is made and rainfall rate is quantified in drizzle time with Logistic model in the frequency bands of 2-15 kHz,and the rainfall rate in heavy rainfall also quantified with log-linear regression.Finally,all measured spectrum data are used to calculate rainfall rate with the algorithm.The results show that the estimated rainfall rates are comparably coincident with the synchronously measured ones.The average error of accumulative rainfall per min is only l%-4%.     

BOUNDED TRAVELING WAVE SOLUTIONS OF VARIANT BOUSSINESQ EQUATION WITH A DISSIPATION TERM AND DISSIPATION EFFECT

This article studies bounded traveling wave solutions of variant Boussinesq equation with a dissipation term and dissipation effect on them. Firstly, we make qualitative analysis to the bounded traveling wave solutions for the above equation by the theory and method of planar dynamical systems, and obtain their existent conditions, number, and general shape. Secondly, we investigate the dissipation effect on the shape evolution of bounded traveling wave solutions. We find out a critical value r*which can characterize the scale of dissipation effect, and prove that the bounded traveling wave solutions appear as kink profile waves if |r| ≥ r*; while they appear as damped oscillatory waves if |r| r*. We also obtain kink profile solitary wave solutions with and without dissipation effect. On the basis of the above discussion, we sensibly design the structure of the approximate damped oscillatory solutions according to the orbits evolution relation corresponding to the component u(ξ) in the global phase portraits, and then obtain the approximate solutions(u(ξ), H(ξ)). Furthermore,by using homogenization principle, we give their error estimates by establishing the integral equation which reflects the relation between exact and approximate solutions. Finally, we discuss the dissipation effect on the amplitude, frequency, and energy decay of the bounded traveling wave solutions.     

THE MAIN INVARIANTS OF A COMPLEX FINSLER SPACE

In this paper we extend the results obtained in [3], where are investigated the general settings of the two-dimensional complex Finsler manifolds, with respect to a local complex Berwald frame. The geometry of such manifolds is controlled by three real invariants which live on T ′M : two horizontal curvature invariants K and W and one vertical curvature invariant I. By means of these invariants are defined both the horizontal and the vertical holomorphic sectional curvatures. The complex Landsberg and Berwald spaces are of particular interest. Complex Berwald spaces coincide with K¨ahler spaces, in the two-dimensional case. We establish the necessary and sufficient condition under which K is a constant and we obtain a characterization for the K¨ahler purely Hermitian spaces by the fact K = W = constant and I = 0. For the class of complex Berwald spaces we have K = W = 0.Finally, a classification of two-dimensional complex Finsler spaces for which the horizontal curvature satisfies a special property is obtained.     

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.     

三角形形状的判定

三角形形状的判定问题,是近年全国各地各类初中数学竞赛中常出现的问题,为使同学们学会运用有关知识和方法进行判定,本文举     

EFFECT OF HEAD SHAPE ON THE ADHESION CAPABILITY OF MUSHROOM-LIKE BIOLOGICAL ADHESIVE STRUCTURES

Theoretical studies have been extensively performed to reveal the mechanism of the biological adhesive structure with a flat head.However,most biological adhesive structures have a big head.Here we investigate the effect of the head shape on the adhesion capability of a mushroomlike adhesion structure based on a finite element model.We show that a mushroom-like head produces significant adhesion enhancement.We investigate also the effect of the elastic modulus of the adhesive structure on the adhesion.Our results are consistent with existing experimental results.     

高分子复合材料微加工

高分子纳米复合是深入理解高分子链结构和宏观性能的关键，直接影响着复合材料向尺寸微小化、控制精细化、复合功能化和系统集成化方向发展的进程，涉及了高分子复合材料微加工中的诸多问题，其中多组分多尺度空间分布和形态精细控制的物理与化学是两个关键科学问题。自2000年起，我们围绕这两个关键问题展开系列研究，主要面向复杂性复合颗粒...     

孔型立轧过程的三维刚塑性有限元分析

采用三维刚塑性有限元法对２Ｓ－Ａｌ板孔型立轧稳态过程进行了分析和比较，所得轧件断面形状，轧制力及轧制力矩与文献「１」的实验结果吻合很好，计算精度有所提高。     

圆锥曲线上点的曲率最大值与离心率的关系

曲线的曲率是指曲线的弯曲程度，而离心率则是指圆锥曲线形状变化，即扁平(狭)的程度，故这两者似有相同之处，那么它们究竟有没有联系?是怎样的联系呢?问题一直困扰着笔者，今提出来与同仁们共同探讨。     

局部形状可调整的三次有理B样条插值曲线

利用三次非均匀有理B样条,给出了一种构造局部插值曲线的方法,生成的插值曲线是C2连续的.曲线表示式中带有一个局部形状参数,随着一个局部形状参数值的增大,所给曲线将局部地接近插值点构成的控制多边形.基于三次非均匀有理B样条函数的局部单调性和一种保单调性的准则,给出了所给插值曲线的保单调性的条件.