近似方法

To solve the B-Ss pricing formulas,there are many popular methods now,such as partial differential equation,analytical approximation,binomial tree methods,finite difference method and Monte-Carlo simulation.

对于Black-Scholes期权定价模型，如今比较流行的定价方法有偏微分方程、解析近似方法、二叉树方法、有限差分方法和Monte-Carlo模拟等。

CA method can provide better approximate results when the differential physical effect of Pi is considered.

当考虑到占有几率Pi的微分效应时，相干近似方法能够提供更好的近似结果。

Therefore scientists have been engaged in research on approximate solutions of the partial differential equations,e.g.,the difference methods,the methods of characteristic curve and MWR method etc.,i.e., by using approx...

因此不少研究分布参数系统的科学工作者对这方程式近似方法进行了大量的研究，如差分法，特性曲线法和MWR法等；或者把分布参数系统近似成集中参数系统，或者把高价方程简化为低阶方程等。

The proposed method is based on a higher order likelihood-based asymptotic procedure. The merits of the proposed method are numerically compared with the signed log-likelihood ratio statistic and the simple t-test method with respect to their expected lengths, coverage probabilities and type I errors.

我们所利用的方法是以概似函数为基础的高阶近似方法，并且我们利用模拟的方法去跟signed log-likelihood ratio及 simple t-test 两种方法比较所建构出的信赖区间的覆盖机率和平均宽度以及所对应检定的型I错误来检视我们所利用方法的优劣。

Finally, the characteristic of nonlinear TM waves propagating in five-layer nonlinear waveguide is analyzed elementarily. The approximate analytical solution is presented based on the characteristic of TM_0, the dispersion relations is given.

最后对非线性光波导中的TM模传输特性进行了初步的研究，利用TM_0模的特性，采取了一种近似方法初步分析非线性介质平板波导TM_0模的近似解，给出了色散关系式。

Using mechanical energy conservation law,the simple pendulum period is analyzed and its exact formula is given.

利用三角函数作为一种近似方法，对单摆的动力学方程进行了简化，给出了大角度条件下单摆运动的周期的近似公式。

When calculating sensitivities matrix, instead of computing 3D sensitivities, we attempt to compute 1D sensitivities. Since the sensitivity elements of nonstations are zero, which should be nonnegligible values, we adopt a method of approximation.

在计算灵敏度矩阵时，吸取近似灵敏度矩阵思想，采用一维灵敏度矩阵来代替三维灵敏度矩阵，并对非测点的灵敏度元素提出一种近似方法。

A character-codes model based pattern recognition method by using amplitude data of targets frequency response is proposed after the establishment of high frequency response equation of radar targets. The method uses the same unvariant character-codes to express the same target of different angles and uses sequential separating of regions of target's reference variables to obtain multiple coding vectors of all regions for every target. The category and pose of target can be determined after a two-staged classification processing such as coding processing of target range profile data and errors correcting processing of coded data. The two-stage classification results are used to target identification as posterior hypothesis to be tested by sufficient convincing and necessary convincing. The character-codes model based pattern recognition method is also adaptive to variation of target angles and controllable in error probability. Time-consuming and complicated iterative computation is not necessary in the train process of pattern recognition.

首先建立了雷达目标的高频频率响应方程，这种方程将目标多散射中心理论与目标局部谐振理论有机地结合起来；进而提出了目标多频响应结构成像方法，这种方法将瑞利区频率响应或谐振区频率响应曲线的不同部位用各种不同的近似方法去逼近，通过特征谱估计方法将目标的局部频响特征与宽带距离响应特征结合起来；然后提出了一种基于姿态角变化区域的序贯划分与多模匹配的特征编码识别方法，这种方法具有能适应目标姿态角的变化以及能控制识别的差错概率α等优点，在目标识别时只需要目标在少数有限个频率激励下的幅频响应数据。

In view of the characteristics of the piston pump's flow ripple, of which the amplitude is large and the harmonic frequences are high, a practical and approximate method for measuring the flow ripple of hydraulic pumps has been advanced.

本文针对较大排量柱塞泵流量脉动幅值大、频宽高的特点，提出了适应于输出通道为等过流面积或近似等过流面积液压泵的流量脉动测试的实用近似方法。

Many methods have been developed in evaluating the QNMs, such as evolving the time dependent wave equation method, integration of the time independent wave equation method, semi-classical method and fraction function method.

许多方法被用来研究黑洞的似正规模：波动方程的时间数值演化方法；波动方程的时间积分方法；半经典近似方法；连分数方法。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。