In this model , the peak of flood , flood total outflow and flood process are to be considered . a calculation program with monte - carlo method and a simplified method for calculating diversion risk are suggested 在该模型中，可考虑水文中的洪峰流量、洪水总量和洪水过程的不确定性及水力的不确定性，提出了用monte - carlo方法计算施工导流风险的步骤和用近似法计算施工导流风险的方法。
On the basis of sga , the validity of improved gaussian approximation ( iga ) method is established in our systems and the accuracy of the bit error rate expression obtained via siga is demonstrated with monte - carlo simulations 在此基础上证明改进型高斯近似法( improvedgassianapproximation ,简称iga )在本文所述系统中的适用性,并利用其简化算法( simplifiediga ,简称siga )得到简洁的误码率近似表达式。
In the amsjpda , targets are divided into approximate clusters . different from the cluster in msjpda , the approximate cluster has one " center target " and the other targets are its " neighbor targets " if there is at least one measurement inside the intersection of the validation gates of the center and the neighbor 在近似法中目标被分成不同的近似聚，与传统聚不同的是近似聚中有一个中心目标，聚中其它目标与中心目标的相关门间有交叠，且交叠区中至少有一个公共量测。
Abstract : the second scalar analysis method to calculate the di ffraction efficiency of grating was described in detail , a simple effective approximation formula to calculate the diffraction efficiency of grating was educed . diffraction efficiencies were given and compared with scalar results , rigorous vector results 文摘:详细介绍了计算光栅衍射效率的二阶标量近似法，推导出一种简单有效的计算光栅衍射效率的近似公式.给出了利用近似公式对几种情况下光栅衍射效率的计算结果，并与普通标量法、严格矢量法的计算结果进行了比较
The error analysis model of sampling system was set up for the first time , by combining the saddlepoint approximation analysis and numerical arithmetic , which greatly increased the potential of further application and improved the reliability of the error approximation of the optical sampling histogram 论文首次建立了采用鞍点近似法与数值算法相结合的取样系统误差分析模型，大大扩展了鞍点近似算法的适用范围，提高了误码率估算的可靠性。论文提出了基于时分取样方法的光子模数转换。
In this thesis , we used the q - switched nd : yag laser pulse focused by lens to pump the cr ~ ( 4 + ) : mg _ 2sio _ 4 crystal , with the pump laser pulse duration and energy of 30ns and 50 mj separately , and got the laser pulse with center wavelength , pulse duration and energy of 1 . 22 m , 8 . 2 ns and 10 mj on the best work condition . on the base of zhangguowei s approximation about gain - switching and the parameter of cr ~ ( 4 + ) : mg _ 2sio _ 4 crystal , we calculated the time characteristics of cr ~ ( 4 + ) : mg _ 2sio _ 4 laser pulse with rate equation by numerical method , obtained the conclusion that the laser pulse duration is only related to the pump energy and cavity length : the larger the pump energy is , the narrower the pulse duration is ; the longer the cavity is , the wider the 本论文采用调qnd : yag脉冲激光通过透镜聚焦后纵向抽运cr ~ ( 4 + ) : mg _ 2sio _ 4晶体,抽运光脉冲宽度为30ns 、能量为50mj ,在较佳工作条件下得到了中心波长为1 . 22 m 、脉宽为8 . 2ns 、能量为10mj的激光脉冲;并在张国威分析增益开关时间特性的近似法基础上,结合实际的cr ~ ( 4 + ) : mg _ 2sio _ 4激光器的相关参数,从速率方程出发,用数值计算的方法更为精确的模拟了cr ~ ( 4 + ) : mg _ 2sio _ 4激光器输出激光脉冲的时间特性,得出了激光脉宽只与抽运能量、腔长有关的结论,即抽运能量愈大,脉宽越窄;腔长越长,脉宽则愈宽。
In this paper , firstly , the theory and the discretization schemes of lbie and the concepts of mls and gmls are introduced ; secondly , lbie method is applied to solve the thin plate - bending problems and four typical examples are given to demonstrate the applicability and validity of the method . the results obtained from numerical examples agree well with the exact solutions and have an excellent rate of convergence 本文首先介绍了无网格局部边界积分方程方法的理论基础和离散步骤，以及移动最小二乘近似法和广义移动最小二乘近似法等概念；其次将该方法初步应用于计算薄板的弯曲问题，建立了完整的积分公式，求解了四个典型算例，结果同精确解非常接近，且收敛快。
The first section introduces the background , significance and the relative development of the dissertation . then the roughness of rough surface and the basic theories of the scattering of electromagnetic waves from rough surfaces are discussed , and the kirchhoff approximation and small perturbation method are presidented in detail 然后介绍了描述随机粗糙面的有关统计特性参量,给出了处理粗糙面散射问题的不同方法,指明了各自的适用条件,并对经典粗糙面电磁散射的kirchhoff标量近似法和微扰法做了详细阐述。
Consult the tolerance method of fix income security ' s market risk , we consequence and conclude the s - y approximate method of tolerance option ' s market risk base on the key theory of var parameter model , and it offer a theoretical foundation of option ' s market risk real time tolerance 参考固定收益证券的市场风险度量方法，在var (风险价值)参数模型的核心理论基础之上，推导并归纳总结出度量期权市场风险的-近似法，为期权市场风险的实时监控提供了理论依据。
