查询词典 parabolic

First, the paper proves the well-posedness of the encryption and decryption problems, which provides theoretical bases for experiments of encryption and decryption; Then presents a fast iterative algorithm, which is proposed based on the special sparse structure of the coefficient matrix of the two-dimensional C-N difference scheme, and successfully experiments on images encryption and decryption; At the end, the security of the methods of images encryption and decryption based on the two-dimensional Pseudo -parabolic Partial Differential Equation is experimented and discussed particularly.

首先证明了基于二维连续模型的加、解密问题是适定的，为加、解密实验提供了理论依据；然后根据模型的二维C-N格式系数矩阵的特殊稀疏结构，给出快速迭代求解算法，并成功地进行了图像加、解密的数值试验；最后对基于二维伪抛物型方程的图像加、解密方法的安全性进行了详细的试验讨论。

Neutral type ; quasilinear ; parabolic differential equation ; systems ; oscillation

中立型；拟线性；抛物微分方程；方程组；振动

Based on modern optimization theory and optimal control theory, this dissertation studies some questions as follows:1. The optimization model of parameter identification of three-dimensional geologic history numerical simulation, algorithm and its applicationGeologic history numerical simulation is a basic content of basin numerical simulation, and the porosity is the major parameter in the evolution and development process of oil-bearing basin. According to the sedimentation and burial mechanism, the physical and chemical principles of oil geology, the mudstone porositys non-linear parabolic partial differential equation has been established.

本文应用现代最优化及最优控制理论，对如下一些问题进行了研究： 1、三维地史数值模拟的参数辨识优化模型、算法及应用地史模拟是盆地数值模拟的一个基础性的研究内容，地层孔隙度是含油气盆地地史演化发育过程中的重要参数，根据地层沉积埋藏机理和石油地质的物理化学原理，通过引入数学物理方程概念，建立了泥岩三维孔隙度场方程，根据问题的特点，给出了方程的定解条件，对方程的动边界也给出了处理方法，并且证明了解的存在性与惟一性，在此基础上建立了以当今实测数据为拟合准则的三维地史数值模拟的参数辨识优化模型，这是一个含有二阶偏微分方程约束的泛函极值问题。

Secondly, point out that meshless method is different from finite element method in handling boundary condition and numerical integral because the approximation function of meshless method is not inserted function, it have itself special methods. Deduces meshless Galerkin essential equation of parabolic partial differential equation with the method ofweighted residuals------Galerkin. Furthermore, discusses the main factors which may effectthe calculation precision and give some suggestion with which can get the best result.

其次，由于无网格法的近似函数不是插值函数，所以无网格Galerkin法在处理边界条件和对区域积分时是不同于有限元的，它有其独特的处理方法，从加权残量法——Galerkin出发，推导出抛物型偏微分方程无网格Galerkin法的基本方程，并对影响无网格Galerkin法的主要因素进行探讨，给出了取得最佳效果的相应建议。

The first step of simulation method is to establish the one-dimension parabolic partial differential advection diffusion equation that was used to describe the mass transportation model of air-pollution distribution as a block program model of the controllable plant. Then, applying the Fuzzy logic theory to operate tunnel jet-fans and control the tunnel wind quantity and adjust the wind average velocity would not let the air-pollution concentration over the standard safety value too much.

模拟方式首先将常被用以表示隧道内空气污染物质传理论模式之一维向平流扩散抛物线型偏微分方程式建构成一组可控制对象的方块程式模拟模型，再运用模糊逻辑理论模拟控制喷流式通风机之运转风量来调节隧道内平均风速以控制隧道内空气污染物浓度不至於高过标准安全值太多。

The experts said that given the nearly parabolic shape of its orbit, the comet Lulin first visit may also be the last.

专家们表示，鉴于其近抛物形轨道，鹿林彗星的第一次造访也可能是最后一次。

Chapter 3 studies the controllability for parabolic equations with point controls.

第三章研究点控制下抛物型方程的能控性。

Point focus parabolic dish with Stirling engine and its solar tracker at Plataforma Solar de Almería in Spain.

点集中抛碟与斯特林发动机和太阳能跟踪平台上的太阳能阿尔梅里亚在西班牙

In the beginning, some people secretly tuned into broadcasts from North Point on their parabolic antennas. But as time passed, the broadcasts no longer came in; maybe the satellites were destroyed.

人们开始接收北方传来的电视信号，但是没过多久信号就消失了，也许卫星已经被摧毁了，除了军用网络，一切计算机网络也被切断了。

It includes the following chapters: o Introduction to MATLAB o Root Approximations and Partial Fraction Expansion o Sinusoids and Complex Numbers o Matrices and Determinants o Review of Differential Equations o Power Series o Linear and Parabolic Regression o Solution of

它包括以下各章： o MATLAB o 根近似值的介绍并且部分分数展开 o Sinusoids 和复数o 矩阵和决定因素o 回顾的线的微分方程o幂级数o 和抛物线回归o 解决办法

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。