差分法
- 与 差分法 相关的网络例句 [注:此内容来源于网络,仅供参考]
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In the light of the complex, high-level and non-linear feature of the mathematical model which describe the transport of the coalbed methane, this paper study the fully-implicit solving method of the mathematical model in detail. Based on the complexity of the algebraic equations which are formed eventually, according to the alternating direction implicit difference pattern, this paper use the iterative method and the fully main element Gauss-Jordan eliminating method to solve equations, which is to use the iterative method to determine coefficient matrix and use the fully main element Gauss-Jordan method to solve th linear algebraic equation group, at the same time of studying the solving method of the mathematical model, according to the devising requirement of FORTRAN77 program structure, this paper draw up computer program and form the corresponding computer model, and verify the validity and reliability of the model in theory by operating the model.
重点研究了模型内、外边界及有关参数的处理,针对描述煤层甲烷运移的数学模型是一个复杂、高阶非线性数学模型的特点,详细研究了模型的全隐式求解方法,根据最后形成的代数方程组的复杂性,按交替方向隐式差分格式,采用迭代与全选主元高斯约当消去法相结合的方法求解方程:即确定系数矩阵采用迭代法,求解线性方程组时采用全选主元高斯约当消去法,在研究模型解法的同时按FORTRAN结构化程序设计的要求,编制计算机程序,形成相应的CBMRS计算机模型,并通过模型的运行从理论上证明了模型的正确性与可靠性。
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The paper according to fractal autoregressive integrated moving average process models network self-similar traffic, estimates fractal dimension through fractal analysis methods directly and indirectly, and emphasizes on rescaled range analysis.
本文由分形自回归整合滑动平均流量模型产生自相似性数据。针对流量分形维数的求解,本文分别从直接估计和间接估计两个方面进行研究,采用分形分析方法对产生的业务流进行统计分析,其中重点讨论了变标度极差分析法。
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Surface tension ; capillary rise method ; differential ; Wilhelmy plate method ; pendent drop method ; drop volume method ; maximum bubble pressure method
表面张力;毛细管上升法;差分; Wilhelmy盘法;悬滴法;滴体积;最大气泡压力法
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The PSE in the curve coordinate systems are solved by the numerical techniques developed efficiently in this paper. A normal transform is introduced, and there are enough much grids in the region between the critical layer and the wall, where the variation of the disturbance is the quickest. The finite-difference of governing equations with fourth-order accuracy in the normal direction is utilized in full regions including points close the wall, and is very important for accurately discreting equations.
对于曲线坐标系下的抛物化稳定性方程,文中发展了求解的高效数值方法:引进法向变换,使得在临界层与壁面之间的扰动量变化最快的区域有更多的法向网格点;导出包含边界邻域在内的完全四阶精度的法向有限差分格式,这对方程精确离散至关重要;采用全局法和局部法相结合的方法及其新的迭代公式,大大加速收敛并得到更精确的特征值。
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Among used machine learning methods, the gradient descent method is widely used to train various classifiers, such as Back-propagation neural network and linear text classifier. However, the gradient descent method is easily trapped into a local minimum and slowly converges. Thus, this study presents a gradient forecasting search method based on prediction methods to enhance the performance of the gradient descent method in order to develop a more efficient and precise machine learning method for Web mining.However, a prediction method with few sample data items and precise forecasting ability is a key issue to the gradient forecasting search method. Applying statistic-based prediction methods to implement GFSM is unsuitable because they require a large number of data items to model a prediction model. In the contrast with statistic-based prediction methods, GM(1,1) grey prediction model does not need a large number of data items to build a prediction model, and it has low computational load. However, the original GM(1,1) grey prediction model uses a mathematical hypothesis and approximation to transform a continuous differential equation into a discrete difference equation in order to model a forecasting model.
其中梯度法是一个最常被使用来实现机器学习的方法之一,然而梯度法具有学习速度慢以及容易陷入局部最佳解的缺点,因此,本研究提出一个梯度预测搜寻法则(gradient forecasting search method, GFSM)来改善传统梯度法的缺点,用来提升一些以梯度学习法则为基础的分类器在资讯探勘上的效率与正确性;而一个所需资料量少、计算复杂度低且精确的预测模型是梯度预测搜寻法能否有效进行最佳解搜寻之关键因素,传统统计为基础之预测方法的缺点是需要较大量的数据进行预测,因此计算复杂度高,灰色预测模型具有建模资料少且计算复杂度低等优点,然而灰色预测理论以连续之微分方程式为基础,并且透过一些数学上的假设与近似,将连续之微分方程式转换成离散之差分方程式来对离散型资料进行建模及预测,这样的作法不尽合理,且缺乏数学理论上的完备性,因为在转换过程中已经造成建模上的误差,且建模过程仅考虑相邻的两个资料点关系,无法正确反应数列未来的变化趋势。
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Firstly,the minimum interclass variance method was improved to obtain the optimal segmentation threshold of difference image quickly,and then,the region growing method was used to segment the target.
首先对最小类内方差法进行改进,快速确定差分图像的最佳分割阈值,再用区域生长法分割得到目标。
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The one order differential model and convolutional model of impedance formula of amplitude versus offset inversion were established. Impedance inversion formula from AVO was derived based on Bayesian framework. Methods of using Huber function as prior model parameter distribution and covariance matrix from well log as constrains were developed. The P-wave impedance, S-wave impedance and density were calculated by the conjugate gradient algorithm.
为此建立了振幅随偏移距变化波阻抗反演公式的一阶差分模型及褶积模型,推导了基于贝叶斯理论的AVO波阻抗反演公式,给出了采用Huber分布作为模型参数的先验分布及测井数据的参数协方差矩阵作为约束条件的实现方法,并利用共轭梯度法计算了纵、横波阻抗及密度。
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The discrete velocity ordinate method in the kinetic theory of gases is developed and applied to discretize the correspo
借助非定常时间分裂法和无波动无自由参数的NND耗散格式,建立直接求解微观分子速度分布函数的有限差分数值格式;研究并发展可用于离散速度坐标点选取和离散速度空间宏观取矩的高斯─埃尔米特无穷积分方法、等均间隔的牛顿─柯斯复合积分法、以勒让德多项式的根为积分结点的高斯─勒让德数值积分法,并应用于不同马赫数绕流模拟;通过对不同流域一维激波管问题、二维圆柱绕流问题和三维球体绕流的计算研究,并将计算结果与其他途径得到的研究结果诸如DSMC模拟值、N-S解及有关实验数据进行比较分析,创建了一套能有效模拟稀薄流到连续流不同流域气体流动问题简化的统一数值算法研究框架
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The presterssed anchor cable frame combined with backwall, drainage is necessary due to longtime sability and permanent utilization.Firstly,according the study of engineering of geology situation of the high slope, the mechanism of deformation failure and the major hazard of the high slope of PanMei is analysed comprehensively.And the whole slope is divided into two different geology enginnering areas:Western slope(1160 section plane -1240 section plane)and Eastern slope(1240 section plane -1320 section plane). The result of 3D numerical simulation is the same as geology judgement. Later,slope cut (1:0.75) is implemented based on the engineering comparison and criterion.Meanwhile, Limit equilibrium method , Monte Carlo Probabilistic slope stability the stability , Sensitivity analysis and Finent element method of for assessing the cutted slope stability is carried out. The result indicates that Western slope is instable, Eastern slope is relatively stable.So much attention should be paid to Western slope.Different reinforcement measures in different areas are given according to its stability and meet economical request. Gravity wall is introduced in accordance with landform in order to prevent small falling at the foot of the high slope ,which will be a threat to the high slope stability. Handling measure is also applied to Eastern slope. At last,FLAC3D numerical analysis shows the feasibility and reasonableness of the handling measure of the high slope.
论文首先研究了边坡的工程地质条件,全面分析边坡的变形破坏机制和边坡的主要地质灾害,将边坡分为西段不稳定边坡区(1160剖面~1240剖面)和东段相对稳定边坡区(1240剖面~1320剖面),通过三维数值模拟再现了边坡在自重作用下的破坏机制和过程;在此基础上通过工程类比和规范要求,确定按照1:0.75进行放坡处理,并分析了放坡后边坡的稳定性状况,分别通过极限平衡法、蒙特卡洛法概率分析、参数敏感性分析和有限元稳定性计算等多种方法对边坡在各种工况下的进行稳定性研究,计算结果表明,西段边坡较之东段边坡稳定情况差,是边坡支护的关键之处,而东段边坡相对是稳定的;边坡的综合治理措施选用的是框架锚索并结合挡土墙和排水工程,治理设计根据不同区段的稳定性情况采用不同的支护结构,做到了经济合理的要求;在边坡的坡脚设置重力式挡土墙,防治边坡小规模的崩塌,会对上部的锚索支护护造成不利影响,进而影响边坡的稳定;东段边坡的填方区也给出了治理对策;最后通过三维显示拉各朗日有限差分程序(FLAC3D)模拟了高边坡放坡和支护效果,论证了治理措施的有效性和合理性。
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With the consideration of various factors affecting on the screening effect,a screening model for drilling fluid shale shaker had been established.
利用流体力学的基本原理,对钻井筛筛面上钻井液的流动特点进行了研究;在综合考虑有关参数对钻井筛筛分影响的基础上,建立了钻井筛的筛分模型,给出影响钻井筛处理量有关因素之间的定量关系;运用平均值法对筛分方程的求解进行了探讨;应用有限差分方法建立了筛分方程的仿真模型,并编写了钻井筛处理量的计算机仿真程序。
- 推荐网络例句
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Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".
歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车,和一双合并为一移交&整个lotta爱&。
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This is Kate, and that's Erin.
这是凯特,那个是爱朗。
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Articulate the aims, objectives and key aspects of a strategic business plan.
明确的宗旨,目标和重点战略业务计划。