查询词典 approximation

I have calculated the species diversity for 3 layers (i.e. tree layer, shrub layer and herb layer) by means of various biodiversity index formulas and analyzed the relative species abundance using 9 models of the probability density distribution functions, such as, 3 Distribution (or Beta Distribution, Weibull Distribution, Lognormal Distribution, Poisson Distribution, Binomial Distribution, Negative Binomial Distribution ,Geometric Distribution, etc.. chi-square analyses were conducted on species distribution by using the chi-square test formulated by Pearson to test which distribution function is better, the result of chi square test made it possible to reject the other 8 distribution functions, theβdistribution function performs better than other probability density functions, it has a very close approximation, which can be used for the description of relative abundances of species in forest communities in this data set.

在相对多度研究上选用了九种概率分布模型，这九种概率密度分布函数依次为：贝塔分布、Weibull分布、对数正态分布、泊松分布、二项分布、负二项分布、几何分布、对数分布和奈曼A型分布，并进行了严格的卡方检验，结果表明：其它八种分布均被遭到拒绝，只有贝塔分布获得了通过，且拟合的结果非常理想。

Accordingly pels tracing and function approximation are avoided ,and vectorization process is simplified effectively.At first ,every arithmetic of image transformation and image filter is researched and its disposal image is analyzed .

本文首先对图像变换和图像滤波的各种算法进行了研究，分析了各个算法的处理效果，根据实验试验结果提出应结合图像本身的特点选择合适的预处理方法，并运用小波变换对图像进行压缩变换和滤波处理。

From our results we know that the average error of the Lagrange interpolation sequence and the Hermite interpolation sequence based on the Chebyshev nodes in the 1-fold integrated Wiener space equal weakly to the average error of their corresponding optimal approximation polynomial in the 1-fold integrated Wiener space,and as a kind of information-based operation,they have simple form and their recover functions are polynomials,in the 1-fold integrated wiener space,their average error equal weakly to the corresponding minimal information radius whose permissible information operators class is function values.

通过我们的结果可以知道，基于第一类Chebyshev多项式零点的Lagrange插值算子列和Hermite插值算子列在1-重积分Wiener空间下的平均误差弱等价于相应的最佳逼近多项式在1-重积分Wiener空间下的平均误差，并且作为形式简单且恢复函数为多项式的一种信息基算法，其在1-重积分Wiener空间下的平均误差弱等价于相应的以函数值计算为可允许信息算子的最小平均信息半径。

Contents: A Brief Review of Elementary Quantum Chemistry; An Introduction to Electronic Structure Theory; The Born-Oppenheimer Approximation; Time Evolution of Wavefunctions; Angular Momentum Summary; The Unitary Group Form of the Hamiltonian; Introduction to Hartree-Fock Theory; Permutational Symmetries of Integrals; Notes on Excited Electronic States; The Quantum Harmonic Oscillator; Assigning Symmetries of Vibrational Modes; Notes on Elementary Linear Algebra

内容： 初等量子化学的简评；电子结构理论的介绍；天生奥本海默的接近； Wavefunctions的时间演化；角动量摘要； Hamiltonian的单位的组形式；哈特里-Fock 理论的介绍；积分的Permutational对称性；在令人激动的电子国家上注明；这台量谐波振荡器；分配振动的方式的对称性；在初等线性代数上注明

We must seek two main approximation methods of solution , the variation method and perturbation theory

我们必须寻求两个主要的近似解法、变分法和微扰法。

There are two kinds of method in common use. One is numerical method, and the another one is analytic approximation which is represented by perturbation method.

常见的方法有两种：一种是数值方法，二是以摄动法为代表的解析近似法。

On the basis of the generalized phase integral approximation and the beam displacement ray mode theory, which are both developed by Chinese acousticians, a fast method for normal modes analyzing including the leaky modes is presented. The application of this method in the coupled mode parabolic equation theory gives an efficient algorithm for both the range dependent problems (CMPE2D) and the three dimensional problems (CMPE3D).

在我国独创的广义相积分理论和波束位移射线简正波理论的基础上，提出了一种可以快速而精确地求解简正波本征值的算法，并将该算法应用于简正波-抛物方程理论，从而实现了二维(CMPE2D)和三维(CMPE3D)声场的快速预报。

By constructing the piecewise linear function from samples, it is able to approximate the measured metric more precisely. Compared with current popular sampling algorithms, FASM algorithm can provide more precise estimation of metric under the same samples. In the condition of retaining the same approximation errors, our adaptive sampling methodology only requires fewer samples, which will save sampling costs considerably during sampling process.

与当前常用的抽样算法相比，在采集相同的样本数量情况下，本文的拟合模型对指标进行的估计更准确、稳定；而在保持相同的拟合误差时，自适应抽样算法则可显著减少所需采集的样本数量，节约数据采集过程的代价。

A rough approximation would be the dual spirals in pinwheel.

粗略地近似风车上的两重螺旋线。

Now, GW approximation is based on all electron calculation and plane wave pseudopotential method.

目前，GW修正计算主要是基于全电子的LMTO修正和基于平面波赝势法的修正。

"The operators will suffer a temporary decrease in the number of consumers and short message services as people may not like having to provide their ID cards for a phone number," Xu Junqi, vice-dean with the Policy-Making Institute of the Telecommunications Research Centre under MII, said yesterday.

信息产业部下属的通信决策研究院副主任徐俊其昨天说：&实行手机实名制后，人们可能不太情愿用身份证注册手机号，所以通信运营商会暂时面临用户减少和短信用户减少的问题。&

I don't believe in make-believe!

我不相信这些虚构的故事。