反演问题

In order to raise a level of the application researches on the back-analysis from displacements,an influence of the loosing zone caused by excavating an adit upon the resultsof back-analysis and how to raise unceasingly its precision,etc.

为了进一步提高位移反分析应用研究的水平，需要认真考虑试验洞开挖引起的松动圈对反演结果的影响和如何不断地提高位移反分析的精度等问题。

But the singularity location inversed by Born approximation inversion is false except the first interface.

本文第二章对Born近似反演算法进行了深入研究和分析，指出了Born近似反演存在的问题。

An analytical model describing the dispersion with an exponential dispersion function is built, which be transformed into CDE problem with variable coefficient, using hypergeometric function and inversion technique, an analytical solution for two type boundary conditions is obtained.

文章对于具有指数弥散函数的弥散过程建立了对流-弥散微分方程模型，应用积分变换将问题转化为具有变系数的常微分方程问题；对于两种类型的边界条件，应用超几何函数和反演技术得到了问题的解析解，并分析了指数弥散过程和常数弥散过程的不同性质。

Firstly, the approach formulates a cost functional to turn the inverse problem into a constrained minimization problem according to least squares criterion, then the resulting constrained minimization problem is transformed into an unconstrained minimization problem by using a penalty function technique, and then the closed Fr chet derivatives of the Lagrange function with respect to the properties are derived based on the calculus of variations, finally, one can solve the resulting problem by using any gradient-based algorithm and the finite-difference time-domain method.

该方法首先以最小二乘准则构造目标函数，将逆问题表示为约束最小化问题；接着应用罚函数法转化为无约束最小化问题；然后基于变分计算导出闭式的拉格朗日函数关于特征参数的Fr chet导数；最后借助梯度算法和时域有限差分法迭代反演德拜模型参数。

For a class of bilevel multi-objective decision,this paper converts it into the problem of equivalent single-level multi-objective decision,then makes use of the inversion property of the genetic algorithm with the ergodic property of the chaos optimization method.

针对求解一类二层多目标决策问题，首先将其转化为等价的单目标决策问题，然后利用遗传算法优化的反演性和混沌优化方法的遍历性，并结合精确不可微罚函数求解非线性约束优化问题，提出了求解此类问题的混沌遗传算法。

For a class of bilevel multi-objective decision,this paper converts it into the problem of equivalent single-level multi-objective decision,then makes use of the inversion property of the genetic algorithm with the ergodic property of the chaos optimization method.Combined with exact non-differentiable penalty function,a new chaos genetic optimization algorithm is presented.

针对求解一类二层多目标决策问题，首先将其转化为等价的单目标决策问题，然后利用遗传算法优化的反演性和混沌优化方法的遍历性，并结合精确不可微罚函数求解非线性约束优化问题，提出了求解此类问题的混沌遗传算法。

A class of bilevel multi-objective programming was converted into the problem of equivalent single-level multi-objective programming. Then a new chaos genetic optimization algorithm was presented by using the inversion property of genetic algorithm and the ergodic property of chaos optimization method and combining with the exact l_1 penalty function.

针对求解一类二层多目标规划问题，首先将其转化为等价的单目标规划问题，然后利用遗传算法优化的反演性和混沌优化方法的遍历性，并结合精确罚函数求解非线性约束优化问题，提出了求解此类问题的混沌遗传算法。

This paper uses Tikhonov regulation method to solve the first kind Fredholm integral equation which gets the solution of the inverse problem in time,and based on the advantage of the genetic algorithms presents a ex- ample of inverse problem.

利用Tikhonov 正则化方法解第一类Fredholm积分方程获得该逆时反问题的解，并结合遗传算法的优点给出了一种反演的例子。

Firstly, it is assumed that the coefficient is known, and we work out the general representation of the pseudoparabolic equation given.

第四章以一类特殊的四阶非线性伪抛物型方程为例，讨论了二维空间上一类伪抛物型方程反演系数的反问题。

By analyzing the cultivated land data from different sources in different phases after 1949,the paper considers the statistics with more errors happens during 1960-1985.According to the systematic data on land use gathered in the 1996 survey,based on reverse deduction of the cultivated land area from 1986 to 1996,and deduction of the cultivated land area from 1960 to 1985 by stages by employing yield of grain,this paper redescribed the actual changing trend and character of Chinese cultivated land and analyzed the driving force of the policy relative to cultivated land to cultivated land area change.

针对该问题，论文对1949～2003年不同时期不同来源的耕地数据系列进行分析，认为统计数据存在问题较多的时期为1960～1985年，并采用粮食产量对耕地面积进行了分时期的反演，对于1986～1996年间的耕地数量则按照全国土地利用详查统一到1996年的结果再进行反推，由此重新刻画建国以来中国耕地资源数量变化的趋势和特征，并结合不同时段耕地相关政策对耕地数量变化的驱动作用进行分析。

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。