查询词典 differential coefficient

One of the primary methods to solve them is numerical method, and the other is Galerkin method, which change partial differential equations into normal differential equations, and then solve them with the traditional method.

小波分析已成为当前应用数学中迅速发展的新领域，它可以解决Fourier分析不能解决的许多困难问题，是近年来在研究工具及方法上的创新，已成为众多学科共同关注的热点。

At present,the hybridization of Differential Evolution with local search method confines to DE with a crossover based local search method.A novel differential evolution algorithm with best-individual based Local Search strategy is proposed.In LSDE,a normal distribution operator is introduced to automatically modify search length,and time-varying factors are introduced to modify the two parameters of DE.

针对目前差分进化与局部搜索相结合仅局限于基于交叉的局部搜索的方法，提出了一种基于最佳个体局部搜索策略的差分进化算法，并引入正态分布算子自动调整搜索步长和时变差分进化因子调整DE的两个参数。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

By adapting the existed numerical methods for ordinary and delay differential equations, and matching certain suitable numerical quadrature formulas, Rosenbrock methods are constructed for delay integro-differential equations, the stability criteria of the methods are derived.

通过改造现有常及离散型延迟微分方程的数值方法，并匹配以适当数值求积公式，构造了求解时滞积分微分方程的Rosenbrock方法，导出了其稳定性准则。

The possible differential rotation among the layers of the Earth interior and its contribution to nutation, as well as the displacement profile interior, are studied, which provides a new method to study the differential rotation of the Earth cores.

讨论了地球内部可能的较差转动对章动的贡献以及地球内部形变场剖面，特别是核幔边界附近的低阶形变场的非线性特性，为研究较差转动提供了除地震学之外的另一种新的可能途径。

BNP play a important role in differential diagnosis of dyspnea as in the octogenarian as in the common gerontism, but BNP prognostic value in the octogenarian was influenced by aging, which must be recognized in differential diagnosis.

BNP对高龄呼吸困难鉴别诊断与一般老年人同样具有特异的重要作用，但在高龄人群中BNP预测值受到增龄的影响，应在鉴别诊断中引起重视。

In this project,we primarily investigated the growth of solutions of some types of differential equations,and the hyper order,the exponents of convergence of zeros and fixed points of solutions with infinite order, especially, expononts of convergence of fixed points of first, second order derivatives and differential polynomials of solutions.

中文摘要：在本项目中，重点研究了几种类型的微分方程解的增长性，及无穷级解的超级，零点收敛指数，不动点收敛指数，特别是解的一阶，二阶导数及微分多项式的不动点收敛指数。

The differential equation is the most vitality branch in mathematics. In many domains of natural science, we can meet the ordinary differential equation solution question.

摘要微分方程是最有生命力的数学分支，在自然科学的许多领域中，都会遇到常微分方程的求解问题。

The course content includes ordinary differential equation, linear algebra, vector calculus, Fourier analysis and partial differencial equation partial differential equation, with the aim to train students in establishing an exact perception to the meaning of theory, calculation and experimentation.

课程内容有常微分方程，线性代数，向量微积分，Fourier 分析及偏微分方程式等章节，训练同学在理论，计算及实验间建立正确的认知及意义。

Differential Evolution Orthogonal Least Square algorithm for RBF network is presented,a hybrid algorithm blending Orthogonal Least Squares method with Differential Evolution algorithm.

研究用于径向基函数网络训练的一种微分进化正交最小二乘算法。

Must have Coordination and negotiation skill, flexible ideas, and be punctilious person.

必须具备较好的协调与谈判能力，头脑灵活，工作认真仔细

Result: 18 patients are all with simple eye.The pigment mole lies in nasal and temple sides of the ball conjunctiva,in which 2 lie in lacrimal caruncle and semilunar plica.

结果：18例患者均为单眼，色素痣大多数位于内外侧睑裂部球结膜面，2例位于泪阜及半月皱襞，经激光治疗后，10例色素痣消失，有5例行再次激光后消失，2例行第三次激光后消失，1例第四次激光后消失。