查询词典 approximation

Neural networks; Function approximation ; generalized Fourier series ; approximation capability

神经网络；函数逼近；广义Fourier级数；逼近能力

In this paper, we discuss rough set approximation under granulation, and establish positive approximation under dynamic granulation.

本文讨论了粒度意义下的粗糙集近似，并定义了动态粒度下的正向近似。

In this thesis the process of constructing the non-perturbative Hamiltonian theory is de-scribed and is applied to estimate the vacuum condensate. It contains the following contents:At the very beginning, by using the path integral method and eliminating the gluon freedom, aGCM action 〓 of current quarks including lower order current-current coupling was derivedfrom the QCD Lagrangian and the effective Hamiltonian operator that could hardly be doneby the normal methods was derived. After doing this, the broken vacuum is introduced whichincludes quark-antiquark condensate through the generalized Bogoliubov-Valatin transformation,the effective Hamiltonian of constituent quark was derived. The detailed formulas containingthe spatial current-current coupling term for the effective Hamiltonian and gap equations wasworked out by parameterizing the correlation kernel as a quadratic potential. And then, the gapequation was solved and the quark-antiquark condensate of vacuum was studied both in the casesof instantaneous interaction and retarded interaction. In the end, the effective Hamiltionian withtwo-body quark-quark interaction was derived with one-body approximation, and with the helpof the functional integral method the coupling non-linear dynamic equations for systems withnuclear matter was derived. Finally, these equations were solved by selfconsistent method andthe effect of nuclear matter on vacuum condensate was studied. The spatial current-current coupling term is too difficult to handle, hence the correlationkernel is assumed to be not important and usually omitted in the pure vacuum condensate, andthe instantaneous interaction generally is adopted. Retaining the spatial current-current termand partial retardation effect, the quark pairs condensate in pure vacuum was studied, and theeffect of quark mass was also studied. At present, little study is focused in the case with nuclearmatter and spatial current-current term also omitted. Under the approximation with partialspatial current-current term, the effect of nuclear matter on vacuum condensate was studied.

本论文描述了量子色动力学整体色对称模型哈密顿量方法的构建过程，得到了反映正反夸克对凝聚真空结构的关于组分夸克的有效哈密顿量算符，它隐含了胶子作用，并且准确至流-流耦合项；接着，通过参数化哈密顿量中的夸克作用关联核，导出平方禁闭势参数化选择的哈密顿量的具体公式和能隙方程；随后，应用公式，编程求解，考察了瞬时作用下和部分延迟作用下真空的正反夸克对凝聚，在计算中保留了空间流-流耦合作用；之后，导出瞬时势和延迟势下包含二体作用项的哈密顿量公式，并采用单体化近似，通过泛函变分方法得到核物质存在时耦合的非线性动力学方程；在保留部分空间双流耦合作用的近似下，求解核物质的动力学方程，考察核物质密度对真空凝聚的影响，以往考察真空凝聚，对关联核的选用，由于空间流-流耦合项不易处理，也认为作用不大，常忽略该项，并且常采用瞬时作用；本文保留空间双流项和部分延迟作用，考察了真空情形的夸克对凝聚，还考察了夸克质量对纯真空凝聚的影响，以往对核物质存在情形的真空凝聚考察很少，也都忽略空间流-流项，本文在考虑部分空间流-流项近似下，考察了核物质存在对真空凝聚的影响。

The main procedures are as following: to generate small increment of parameters automatically and to calculate the FE several times and obtain the sensitivity of objective function to the parameters, and then form a Hermite polynomial approximation, the calculation of FE solutions are substitute by the calculation of polynomial approximation, so time cost decreases dramatically.

用n维埃尔米特插值技术建立设计变量在可行域上的目标函数的逼近函数；将局部寻优的梯度算法和全局寻优的随机算法结合起来，大幅度地降低寻优过程中电磁场的计算次数。

First the approximation problems are obtained by approximation to the initial datum.

第三部分研究基本半导体方程混合初边值问题解的整体性质。

The effects of the initial values and the network approximation error using neural network model composed of feedforward neural net and delayed output feedback in the approximation of NARMAX system are studied, and a conclusion is drawn that under some weak conditions the output of the network model has little difference from that of the actual system.

研究了用带有延迟环节的前馈网组成的网络模型逼近NARMAX系统时网络逼近误差及运行初始误差对网络模型输出的影响，指出在一些弱的条件下网络模型输出与实际系统输出间相差不大。

There are substantial relation between the interpolation and approximation of functions.The interpolation polynomial is regarded as the important tool of achieving approximation of function.

函数插值与函数逼近有着密切的联系，插值多项式可看作实现函数逼近的一种重要工具。

And several rough set operation algorithms are also offered in this paper,such as upper approximation set,lower approximation set,intersection, cardinal number and so on.

通过讨论二进制与粗糙集之间的内在联系，提出基于二进制的粗糙集运算理论，并借助二进制的位运算操作，给出粗糙集的上近似集和下近似集、等价类的交、集合的基数的运算算法。

The objective function of the QP problem is a quadratic function which is an approximation of the Lagrangian function of the constrained problem and the constraints of the QP problem are linear approximation of the constraints of the constrained problem.

这些二次规划子问题的目标函数是原约束最优化问题的Lagrange函数的某种二次近似，其约束条件是原约束条件的线性逼近。

By applying the concept of "dominant input",the existence of both the approximation error and external disturbance which are supposed to have unknown boundaries is considered.What's more,the adaptive law utilizes two types of errors in the adaptive fuzzy systems,the tracking error and approximation error.

该方法应用"主导输入"的概念，同时考虑了函数逼近误差和系统外扰的存在，假设了该系统逼近误差和系统外扰有界但界未知的情况；并探讨了自适应模糊控制器的参数自适应律由跟踪误差和逼近误差共同进行调节。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。