查询词典 initial approximation

This makes more and more people pay more attention to studies and applications of numerical simulation in thermal recovery. In this research, we have developed a reliable mathematical model for thermal recovery, which takes a full consideration of the effect of viscos, gravitical and capillary forces on the three-phase flow of gas, water and oil, the effect of the temperature on the medium characteristics of liquid and solid, the phase equilibrium of gas-liquid in each component, heat transportation including connection, conduction and radiation as well as heat losses in both the overburn and underlying strata. In the space discreation of the mathematical model, we have proposed a new method based on the improvement of the conventional nine-points difference approximation, which has a higher difference accurancy.

本项研究以热力采油的主要机理为基础，充分考虑在粘性力、重力和毛管力作用下油水气三相流动，考虑温度对各种流体和固体介质物性的影响，考虑每一组分中汽液两相的相平衡，考虑热在地层中的传导、对流和辐射以及上下盖层的热损失，利用热力学第一定律、质量守恒定律和流体迁移定律，建立了正确可靠的注蒸汽数学模型；在对数学模型进行空间离散时，利用控制有限体积积分法，对以往的九点差分近似作了合理的改进，使其具有较高的差分近似精度：结果表明，该公式的近似精度要比以往文献中所给的九点差分近似精度高，可以认为，在油藏数值模拟中，如果遇到非均质情况，使用这种九点差分近似更合理。

In this paper,the authors give a strict proof of geometric Brown motion displayed by stock prices using the methods of approximation from discrete process to continuous stochastic process.

通过由一般的离散过程逼近连续随机过程的方法，给予证券价格按有漂移率的几何布朗运动变化的一个严格的证明，并指出了股票价格过程的一般模型

Periodical interference can be represented in a good approximation with a discrete Fourier series.

这类干扰信号的频率若落在有用信号的频谱范围之内，用频域处理方法则很难将其单独消除。

The mechanism of the least squares approximation that MFNN with finite nodes carried out on a given discrete point set is made, which, for the first time, results in an important theorem.

分析了有限规模多层前向网络用于离散点集上的最小二乘逼近的机理，首次给出了一个有关的定理。

Among these methods, it is surprising that few if any fundamental treatments of decoherence exist that include the dynamics of disentanglement with better than the Markovian approximation or phenomenological tradition.

所以研究环境对量子系统的影响，以便减缓环境对其包围下的量子系统的耗散、退相干、退纠缠等负面作用，就成为当今非常重要的课题。

Using the adiabatic approximation, the expression of the mean dissipative force are acquired.

利用绝热近似，给出了平均辐射压力的表达式。

Utilizing the linear approximation lemma, we construct one distinguisher to distinguish the weak Key-IVs for each Grain version.

虽然弱Key-Ⅳ出现的概率很低，但可以说明这两个算法的密钥初始化过程存在安全问题，有必要进行修改。

The disyllabic pitch model is obtained with the help of cubic polynomial approximation and neural network technique.

双音节音高模型是韵律调节的基础；将Kohonen自组织神经网络技术应用到音高模型的分类，并取得了较好的分类效果；（4）基于正弦模型表示的汉语语音分析与合成：将正弦模型引入到汉语的语音分析合成中来，提出了汉语的基于正弦模型表达的分析合成算法，并对在汉语普通话语音合成中的应用，包括汉语四声的变调、时长音高的调整等进行了深入的研究；对于合成音节之间的拼接问题作了探讨，并提出了自己的观点；在国内外的文献中，还没有对于该方法用于汉语语音的分析合成的应用的报道，因此是本文的主要贡献之一。

Although finding the Minimum Connected Dominating Set in an arbitrary graph is a NP-hard problem, many approximation algorithms have been proposed to construct a serviceable CDS.

由于求解最小连通支配集是一个NP难问题，许多近似算法被提出用于构建可用的最小连通支配集。

Although finding the Minimum Connected Dominating Set in an arbitrary graph is a NP-bard problem, many approximation algorithms have been proposed to construct a serviceable CDS.

由于求解最小连通支配集是一个NP难问题，许多近似算法被提出用于构建可用的最小连通支配集。

Pachomius manual labour was organized as an essential part of the monastic life; and since it is a principle of the monks as distinguished from the mendicants, that the body shall be self-supporting, external work of one sort or another has been an inevitable part of the life ever since.

根据圣pachomius体力劳动组织作为一个重要组成部分寺院生活；以来，这是一个原则的和尚，作为有别于乞丐，该机构应自支撑，对外工作的这种或那种已一个必然的一部分，生活至今。

In order to study the effects of parametrical rolling on the ship movement and tilts, in allusion to ship's navigating in regular following waves, the equation of ship rolling motion is transformed into normal Mathieu equation by proper variable replacement when strong parametrical excitation in restoring moment varied according to sine or cosine wave.

为研究参数横摇对船舶运动和倾覆的影响，通过对船在规则波上随浪航行时，恢复力矩中出现的1个以正余弦规律变化的强参数激励项进行适当的变量置换，将船舶的横摇运动方程转换成标准形式的Mathieu方程。