查询词典 discrete optimization problem

In this dissertation, a semi-discrete method-the discrete method of separation of variables is proposed for solving the composite materials problem on a polygon.

本文研究求解带奇性的二阶椭圆型方程、复合材料问题及不可压材料问题的离散分离变量法。

Insection 4.3, semi-discrete and fully discrete Fourier spectral and pseudo-spectral schemes are constructed. The convergence and stability for the schemes are proved, and the error estimates are obtained.Chapter 5, consider the damped coupled generalized nonlinear wave equations. In section 5.2, by coupled a priori estimates and Galerkin method, prove the existence and uniqueness of the global smooth solution for the periodic initial value problem and obtain the existence of global attractors.

第四章，考虑一类具耗散的广义KdV方程组的周期初值问题，在第二节中证明了整体光滑解的存在性和唯一性，得到整体吸引子；在第三节中构造了半离散和全离散的Fourier谱格式和拟谱格式，在整体光滑解存在的条件下，证明了这些格式解的收敛性，并得到了误差估计。

The numerical results show that our method is effective. For the noncharacteristic Cauchy problem for 2-D and 3-D heat equation, we give the explicit H\"{o}lder type stability estimates by using weighted energy method. Especially,H\"{o}lder type stability estimate for discrete solutions of the heat equation is obtained through a fully discrete method. The numerical results are presented.

对于二维和三维的热传导方程的非特征Cauchy 问题，我们利用权函数方法，给出了一个显式的H\&{o}lder 型的稳定性估计，特别的，对于二维的非特征Cauchy问题，我们利用充分离散的方法，对二维问题的离散形式同样给出了H\&{o}lder 型的稳定性估计，同时，我们也给出了数值例子来说明我们的估计。

The new calculation method of structural surfaces with different scales is given on the basis of block discrete element method in which contacts face to face. Moreover, a new discrete element model for simulating rock and soil blasting problem is built. The elements of new model can be split by itself in the program. There are small scale blocks around the charge, and large scale blocks are adopted in far zone.

在块体离散元面－面接触的基础上，给出不同尺度结构面的计算方法，建立离散元对岩土爆破模拟的计算模型，实现块体白分裂计算程序，在药包附近采用小尺度块体，远区采用大尺度块体，可以更为准确地描述爆破载荷下岩体结构面的尺寸效应。

After a further analysis based on the empirical results,a trial probe on the cognitiveprocessing mechanism of the problem representation of the word problem in two types of MLDwas made by the author.The MRD performed much poorer than the MLD only in the mostdifficult equation listing of word problem and the medium and most difficult problemrepresentation of word problem,which showed no difference in computation and comprehensionof simple meaning of the problem,but the gap between two types of MLD became wide as afunction of difficulty and cognitive loading.It indicated that the MLD only had some advantage over MRD for they used more cognitive skills to solve the problem.

基于以上实验的结果，对两类数学困难小学生的应用题问题表征的认知机制作如下推断：混合型数学困难学生仅在高难度水平的应用题列式成绩和中高难度水平应用题问题表征水平上比单纯型数学困难学生得分显著低下，表明两类数学困难小学生在计算能力与理解简单题意的能力上并无差异，但随着难度提高，认知负荷加重，两类数学困难学生在应用题解题上的差异得以突显，表明当需要运用更多的认知能力解决问题时，单纯型数学困难学生比混合型困难学生更具优势。

The problem of finite precision multiuser decorrelator is formulated as linear bounded integer optimization problem,and the problem is shown to be NP-hard problem.

该文首先分析了应用有限精度序列为解相关矩阵序列的解相关接收机，将有限精度解相关的多用户检测问题归约为线性约束整数优化问题，同时证明此问题为NP-hard问题。

Based on Pontryagin maximum principle, the lunar soft landing problem is transformed into a two-point boundary value problem in mathematics. In consideration of the bound condition and transversality condition, the resulted two-point boundary value problem is converted into a parameter optimization problem aiming at the initial values of conjugate variables and the terminal time, then it is solved by the nonlinear programming.

首先，从庞德里亚金极大值原理出发，将有限推力作用下月球软着陆问题转化为数学上的两点边值问题；在考虑边界条件及横截条件的前提下，将该两点边值问题转化为针对共轭变量初值和末时刻的优化问题；然后应用非线性规划方法求解所形成的参数优化问题。

Quadratic assignment problem is a NP-hard combinatorial optimization problem and has been applied in various fields. There are always many zero elements in the flow matrix or distance matrix of the quadratic assignment problem instances which are abstracted from the practical problems. Much computation time can be saved if we can first reduce the size of the problem by using its zero elements.

二次分配问题(quadratic assignment problem， QAP)是应用于诸多领域的组合优化NP-难题，许多从实际问题中抽象出来的二次分配问题，其流矩阵与距离矩阵中存在大量零元素，如果在该类二次分配问题的求解中，能够充分利用这些零元素的信息，将大大缩减问题的规模，节省大量运算时间。

Moreover, if the optimization problem has certain special feature, the simpler relaxation methods can be provided. For example, considering a generalized geometric programming problem, relevant relaxation linear programming can be obtained using its special structure. Based on the branch and bound method, a linear relaxation algorithm of global optimization is presented for generalized geometric programming, and the convergence of the algorithm is also proven.

此外，当优化问题具有某种特殊性质时，我们能给出更加简便的松弛化方法，如考虑广义几何规划问题，能充分利用其特殊结构，建立了广义几何规划问题的松弛线性规划问题；在分枝定界技术的基础上，提出了一个求广义几何规划全局解的线性松弛算法；证明了算法的收敛性。

The membership function can exactly express the fuzzy satisfaction set by considering the vagueness of satisfaction degree of objectives and introducing the membership function for the fuzzy satisfaction sets of system reliability and system cost. The normal distribution and Cauchy distribution of this membership function is modified according to the fuzzy satisfaction sets. By doing this, the multi-objective optimization problem can be converted to a single-objective optimization problem to be solved.

模型充分考虑到目标满意度的模糊性，通过引入系统可靠度与费用的模糊满意集的隶属函数，并根据它们的模糊满意集对其正态分布、柯西分布进行适当修改，使之能够准确表达通常情况下的这两个目标的模糊满意集，最终，把两目标优化问题转化为常规单目标优化问题求解。

The teacher likes the honeymouthed little girl very much.

老师很喜欢这个嘴甜的小姑娘。

Mr. Notker Bien's interests are traveling, spending quality time with the family and long-distance-running.

诺特卡·柏恩先生热爱旅游，长跑，以及和家人一起共度美好时光。