近似方法

Using semidefinite programming relaxation and randomized rounding, we give the corresponding polyniomal approximation algorithms for some NP-hard combinatorial optimization problems.

我们对于一些NP-难的组合优化问题，采用半定规划松弛和随机舍入的方法设计了多项式时间的近似算法，这些算法的性能比都是目前为止最好的结果。

In each subperiod, the DUMOP is seen as a static multi-objective optimization problem by taking the time parameter fixed.

该方法首先将DUMOP的时间变量区间进行了等间隔分割，在每个子区间上把DUMOP近似为静态多目标优化问题。

Plasma specific antibodies IgA, IgG, IgM to Cpn were measured by microimmunofluorescence test. A group of individuals with Cpn specific IgA (titler:32) suggested chronic Cpn infection were compared with a group of control subjects with IgA (titler:32). Blood specimens were drawn for determination of serum lipids and Cpn antibodies. And the serum lipids profile were compared in the two groups.

横断面研究方法；采用微量免疫荧光法检测血浆中肺炎衣原体特异性抗体，以肺炎衣原体IgA升高（滴度≥1：32）的125名健康体检者为研究组，以性别、年龄近似但IgA必抗体效价不升高（滴度：32）的64名同期体检者为对照组，比较2组血清总胆固醇、甘油三酯水平的差异。

Based on density functional theory with the generalized gradient approximation and a full-potential linearized augmented plane wave method, the calculation of the electronic structures and the magnetic properties on [Cuμ-1,3-N3](ClO4), where L is the tridentate Shiff base, has been performed.

基于广义梯度近似密度泛函和全势能线性缀加平面波方法，本文对聚铜络合物[Cuμ1，3-N3](ClO4)（其中L=tridentate Schiff base为三齿席夫基）的态密度和磁矩进行了计算。

By usingthe dynamica l programming method, the optima l investment portfolio andconsumption policies for one kind of typica l utility function case areobtained,then we make numerica l simulation for it and get the numerica lsolution.

然后运用动态规划方法，对于一类特殊的效用函数情形，求出了最优投资组合及消费选择的显性解，并进行数值试验，得出了值函数的近似解，最后将值函数的解析解和数值解进行比较，得到了相对误差示意图。

Because precise determination of a computer virus is undecidable,a method based on improved K-nearest neighbor to detect computer virus approximately is presented in this paper.

由于计算机病毒检测的不可判定性，提出了一种基于改进的K最近邻检测方法来实现对计算机病毒的近似判别。

In this way,after the viscosity or apparent viscosity of virgin crude,corresponding unsheared PPD-beneficiated crude and the sheared PPD-beneficiated crude at a certain temperature are determined,the parameters in the model can be calculated.

按照此方法，只须测定一定温度下空白原油的粘度或表观粘度、未剪切时加剂原油的粘度或表观粘度，及在某一个剪切温度下及某一个粘性流动熵产条件下原油的粘度或表观粘度，即可近似确定该数学模型中的参数，从而预测在不同温度时剪切后的原油在该温度下的粘度或表观粘度。

The data of the company management is essentially an unstationary time sequence. Regarded as a signal, the time sequence is decomposed into different frequency channels. Then wavelet decomposition and reconstruction are used to analyze and forecast the time sequence.

把公司管理上的数据看成一个非平稳的时间序列，利用小波函数将该时间序列分解到不同的频率通道上，然后将分解后的信号当作近似的平稳时间序列，用一些传统的统计方法进行预测。

The DNG structure unit is composed of square split ring resonator and strip wire. The modified NRW method is used to extract the equivalent permittivity, permeability, and refractive index from the scattering parameters of the two-port waveguide with DNG structure. At the designed operating frequency, the refractive index approximates zero, which makes the nondirective electromagnetic wave tend to approximate plane wave along the normal direction of the superstrate and congregate the radiation energy.

以方形的SRR环和金属条带构成双负媒质结构单元，使用修正的NRW方法，通过放置双负媒质结构的二端口波导的散射参数，提取了等效的介电常数、磁导率和折射率，在所设计的工作频率，折射率接近于0，可以将原本发散的电磁波整理成趋近于覆层面法线方向的近似平面波，起到能量汇聚的功能。

The DNG structure unit is composed of square split ring resonator and strip wire. The modified NRW method is used to extract the equivalent permittivity, permeability, and refractive index from the scattering parameters of the two-port waveguide with DNG structure. At the designed operating frequency, the refractive index approximates zero, which makes the nondirective electromagnetic wave tend to approximate plane wave along the normal direction of the superstrate and congregate the radiation energy.

以方形的SRR环和金属条带构成双负媒质结构单元，使用修正的NRW方法，通过放置双负媒质结构的二端口波导的散射参数，提取了等效的介电常数、磁导率和折射率，在所设计的工作加热板频率，折射率接近于0，可以将原本发散的电磁波整理成趋近于覆层面法线方向的近似平面波，起到能量汇聚的功能。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。