查询词典 adjoint differential expression

The results of numerical experiments, using the four-dimensional variational data assimilation system of the nonhydrostatic mesoscale model MM5, show that: the tangent linear model and adjoint model conducted by keeping the "on-off" switches the same as the basic state, can provide a good approximation of the first-order information to the NLM perturbation and a good descent direction for the minimization procedure; switching on and off at every other time step in the Kuo cumulus parameterization scheme don"t impact the convergence rate of cost function; the existence of the switches don"t impact improvement to the MM5 model rainfall prediction because that not only specific humidity ,but also wind, temperature and pressure are assimilated into the model.

非静力中尺度数值模式MM5的四维变分资料同化系统进行的数值试验结果表明："开关"变量保持与基态一致，所构造的切向线性模式能够提供关于非线性模式扰动的一阶近似，伴随模式所计算的梯度值能够为最小化过程提供较好的下降方向；郭氏降水参数化方案中对流每隔一个积分步的交替发生并不影响目标函数最小化的收敛速度；"开关"变量的存在也不影响将风、温度、气压和比湿结合起来同化对MM5降水预报准确性的提高。

We discuss the completely tr-rank nonincreasing linear maps on finite vN algebras and prove that a unital self-adjoint and surjective linear map on finite vN algebras is completely tr-rank preserving if and only if it is a spatial 〓-automorphism that leaves the central elements fixed.

我们刻画了有限vN代数上完全迹秩不增的线性映射；也证明了有限vN代数上保单位元的自伴线性满射完全保迹秩当且仅当它是空间〓-自同构且限制到中心上是恒等映射。

In the first part of this paper, we give some basic concepts of regular Sturm-Liouville problems and some Sturm-Liouville problems with eigenparameter in the boundary conditions and the definition and properties of the Krein space. Using the Krein space, we describe a class of Sturm-Liouville problems with eigenparameter in two boundary conditions and prove that it can generate a self-adjoint operator in Krein space with only point spectrum.

第一部分我们介绍了一些基本概念如正则Sturm-Liouville问题、边界条件含参数的问题、Krein空间等，并利用Krein空间的定义和性质描述了一类参数边界条件的Sturm-Liouville问题，证明它可构造一Krein空间上的自伴算子，并且谱全为点谱。

In the computational methods of TPBVP, in order to reduce some difficulties involved in solving a TPBVP via adjoint variables, we discuss a direct method in which state and control variables are indirectly parameterized, The method employs a recently developed direct optimization technique that uses a piecewise polynomial representation for the state and control variables, thus converting the optimal control problem into a nonlinear programming problem, which can be solved numerically.

在数值解法中，为了减少解决两点边值问题共轭变量带来的困难，主要讨论了将状态变量和控制变量进行参数化的一种直接方法，这种方法采用了近段发展起来的使用分段的多项式来代替状态和控制变量的直接优化方法，然后最优控制问题就转化成可以用数值方法解决的非线性规划问题，使得迭代初值更加容易选取。

The AF3 scheme has been used in the adjoint solution for potential flow.

在设计问题中，需要定义的形状函数能够表达一个丰富的设计空间，文中比较了分别使用Hicks-Henne函数和B-样条作为形状函数时，设计过程的不同。

Therefore, the genetic algorithm with the assimilation of GPS precipitable water data are performed to simulate the heavy rain process, and to carry out comparision experiment of adjoint 4DVAR model.

因此，采用遗传算法同化系统研究了GPS可降水量资料在暴雨模拟中的作用，并做了与伴随同化系统的对比试验。

In this paper the relationships of a prime submodule K of a right R-module M and its adjoint prime ideal adj=1 are investigated.

研究右R-模M的素子模K和它的伴随素理想adj＝之间的关系。

The influences of derivations and adjoint ideal semigroups of prime ring with characteristic 2 on the prime ring are discussed, and several sufficient conditions for the prime ring being communitive ring or S4-ring and some necessary conditions for a class of prime rings being communitive rings are obtained.

先给出了一个利用导子和理想来判断素环的可交换性结论的证明，然后讨论了特征为2的素环的导子和归联理想半群对这个素环的影响，得到了素环成为交换环或者S4-环的几个充分条件及一类素环成为交换环的必要条件。

In the end, we built a model of the 4-D variational data assimilation for a barotropic primitive equation based on GA and compared with the adjoint assimilation model.

同时，以正压原始方程组为例建立了基于遗传算法的变分同化模型，并从多方面与伴随模式变分同化系统进行了分析比较。

The following are the major work in this thesis which has been studied and still needs to be studied further in the future: 1 An improved adjoint variational method is developed, thus it can be applied to the LAGFD-WAM Wave Numerical Model for data assimilation; 2 A linear evolution equation of spectral perturbation is derived in order to analyze its increasing or decreasing mechanism.

本论文主要完成了以下几个方面的研究： 1）建立了推广形式的共轭变分同化方法，使之能够应用于LAGFD-WAM海浪数值模式； 2）导出了扰动谱线性演化方程，分析了扰动谱增长、衰减机制，考察了涌浪情况下扰动谱的持续时效问题及风浪情况下扰动的演变过程； 3）利用波谱共轭方程初步分析了同化模型中距离泛函的敏感性及敏感区域空间分布； 4）将推广的共轭变分方法应用于海浪谱能量平衡方程，建立了连续形式的海浪同化模型，特别是严格导出了风输入、破碎、底摩擦、波波非线性相互作用和波流相互作用各源函数的共轭源函数表示式； 5）分别进行了波谱层次上和有效波高层次上的同化试验，并对数值结果进行了分析。

Yet, Edith says, there was always money in the bank.

但是Edith说，她的银行户口里面总是有钱。

We have created a series of files that resolve this problem--one for each day of the 40 days of purpose.

我们制作一系列的档案去解决这问题---一个为标竿40天中的每一天。