查询词典 difference equation

Firstly, based on the method of pressure-velocity coupling introduced by SIMPLE algorithm and a revised method of solving the unsteady equation of stream function and vorticity on uniform grid, a special algorithm called primitive-variable-time-dependent approach is formed in the present study. In this algorithm the Navier-Stokes equation in primitive variable form is solved by using the time-dependent approach on non-uniform staggered grid system. The second-order accuracy finite difference is used for the first and second partial derivatives of all variables of the convective terms and diffusion terms.

首先，本文在SIMPLE算法系列处理速度与压力耦合问题的思路和均匀网格下改进的关于流函数涡量方程的数值求解方法的基础上，将非定常原始变量Navier-Stokes方程的求解推广至非等距交错网格剖分，形成了具有本文特色的原始变量时间推进方法，其中对流项和扩散项中各变量的各阶导数均采用二阶精度公式，包括温度在内的离散方程组采用ADI迭代方法求解。

Around the finite solution problem of fuzzy differential equation, the fuzzy structure element method is put forward about the calculation of fuzzy analysis, and this method is applied to systematically study many problems such as formulation of fuzzy-valued function, difference of fuzzy-valued function, integration of fuzzy-valued function under the Riemann meaning, and the solution structure of fuzzy differential equation etc..

围绕模糊微分方程定解问题，提出了模糊分析计算的模糊结构元方法，并利用模糊结构元的方法对模糊值函数的表述问题、模糊值函数的微分、黎曼意义下的模糊值函数积分以及模糊微分方程的解的结构等问题，进行了深入系统的研究。

In this paper, we present a class of equation model for image denoising and edge enhancement. The model is based on robust statistics error norm and variational theory. By analysing the parameters of the equation and designing the methods of module partitions, the numerical experiments reach a good result and the parallel efficiency has been improved remarkably with finite difference method.

本文基于稳健统计误差模函数及变分原理构造了一类用于图像去噪、增强边缘的方程模型，对相关参数进行了分析，设计了该方程有限差分数值求解的并行算法，并对分块模型及实现过程进行改进，提高了并行效率，在此基础上完成了并行数值实验，并对结果就误差模选取、并行效率等方面进行了分析。

The major implementations of the developed model include: Pseudo-spectral and finite-difference schemes are employed to approximate the spatial-differential operators in the horizontal and vertical directions, respectively. A second-order Runge-Kutta method is adopted to integrate in time for the velocity field and the free-surface elevation. The solenoidal condition of the velocity field is satisfied by solving the transformed pressure Poisson equation. A modified secant method is used to accelerate the iterative solution of the non-separable Poisson equation.

模式的主要数值方法包括：分别以拟频谱法以及二阶有限差分法近似控制方程与边界条件中的水平与垂直导数；以二阶Runge-Kutta法进行非稳态的自由液面位移与流场速度的时间积分；利用改良式割线叠代法求解计算区间中不可分离的压力Poisson方程式，以满足不可压缩流条件。

In this paper differ ce equation of motion fr om one point to another point on the earth is derived from the geodesic equation on the earth and spherical trigonometry formulas. Some difference track formul as of a maneuvering object are also given.

以大地 椭球三角形模型为基础，利用地球表面二点间最短路径的大地线方程和球面三角形的有关公式，建立了由地球表面一点运动到另一点的差分运动方程，同时也给出了在进行航向机动时的差分运动轨迹。

The supposed terdiurnal phases and those observed agree well. By subtracting the estimated tidal zonal QPC equation from the meridional, a tidal phase difference correlated equation is obtained.

周日、半日和8 h潮汐经纬向分量的二次相位耦合方程初分别估计出来，利用它们相减还得到一个潮汐相位差相关方程。

When data are balanceable, two methods should have no difference, but the standard error computed by two-level model is bigger than that by generalized estimating equation. When data were unbalanceable, generalized estimating equation shows somewhat advantage. Type 2 diabetes mellitus might exist genetic heterogeneity and there is no gene that is related with the occurrence of bipolar disorders.

当数据平衡时，两者结果一致，但多水平模型计算出的标准误大于广义估计方程算出的标准误；当数据不平衡时，两者结果不一致，广义估计方程更能检测出有统计学意义的基因位点。

The SIMPLE method is applied in the calculations of Reynolds averaged flow equation and к-εturbulence equation. By using DPIV system and pressure difference gauge, the detail measurement of water flow in the horizontal plane of fork tube is made.

计算中选择SIMPLE方法求解三维雷诺平均方程和k-ε两方程湍流模型，实验采用数字图像测速系统和在试验段前后断面上安装液体差压计对三岔管中心的水平面内的压强差进行测量。

Muti antennae GPS/Gyro integrated navigation system is studied too in this paper. Using single difference GPS carrier phase observations and quaternion error, state equation and measurement equation is established for muti antennae GPS/Gyro integrated navigation system.

本文也对多天线GPS/Gyro组合捷联航姿系统进行了研究，利用单差载波相位测量的方法，建立了基于四元数误差的多天线GPS与Gyro组合航姿系统的状态方程和量测方程。

The central inner gear theory equation and tooth profile work equation with two-teeth difference cam profile rolling movable teeth were deduced, and in the consideration of central gear influenced by several parameters, the central gear tooth profile modification mode was analyzed and synthesized roundly.

推导二齿差凸轮激波滚动活齿传动的中心内齿轮理论方程及工作齿形方程，在给出考虑各参数影响的中心轮修形通用方程的基础上，较为全面地对中心轮齿廓的几种修形方式进行分析和综合。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。