查询词典 mathematical model

The first kind is 0-equation model. It only includes mass and momentum conservation equations. Great progresses have been made in improving this model. It has successfully been applied to many natural rivers with complicated boundary geometry. The second kind is κ-ε model. The κ equation and ε equation are needed, besides mass and momentum conservation equations. Many researchers have studied the depth-averaged mathematical models of turbulence in recent years. However, the models were used mostly in regular artificial canals or natural water areas with simple boundaries.

对于宽浅型河流，采用深度平均法进行流场计算时，用得较多的有两类模型：一类是不增加任何脉动量的偏微分方程的模型，这类模型已在适体坐标下运用得较多且较成功；另一类是κ-ε二方程模型，它是近几十年来广泛应用的一类湍流模型，并发展了许多具体的形式，但大多数只对顺直河道进行了研究，对弯曲较大的河道研究不多，本文运用适体坐标，采用正交交错网格及非正交交错网格，把此模型运用到了弯曲较大的河段及具有汇流的河段，取得了较大的成功。

On the basis of the study on the mathematical model of the closed-loop location control, the analysis of contour error in the process motion control and error calculation model, according to the lack of using normal contour error model not to calculate contour error of curve in real-time, combining real-time contour error compensation control strategy and fuzzy logic theory, the fuzzy logic and real-time contour error calculation based self-discipline control strategy is proposed.

2在研究闭环位置控制数学模型、加工轮廓运动控制中的误差分析和轮廓误差计算模型的基础上，针对利用一般运动轮廓误差计算模型不能实时计算出曲线轮廓误差的不足，结合实时轮廓误差补偿控制策略和模糊逻辑理论，研究了基于模糊逻辑理论和实时误差计算的轮廓自律控制策略。

First, we accomplished the mathematical model and suitable finite elements of grid notes of the pressure hull, including the model without aperture and model with apertures and other added equipments.

首先，本文完成了德国U209型潜舰压力壳(含未开孔模型与开孔模型)之数值模型与网格，并以此模型测试使用不同尺寸的内肋骨补强下，外壳所承受的应力与变形、挫曲强度的不同，藉此推测该设计条件下，最佳的结构设计。

A problem of cable force optimization of cable-stayed bridge is equated as a nonlinear implicit optimization model. In the mathematical model, the object function is minimizing summation of bending strain energy and axial strain energy, and the constrain conditions are nonlinear and related to reasonable finished dead state. The optimization model is solved by projection gradient method, fully considering all kinds geometric nonlinearity.

把超千米级斜拉桥的索力优化问题归结为非线性隐式优化的数学模型，以系统最小弯压应变能为目标，根据合理成桥状态指定各种非线性约束条件，利用投影梯度法进行优化问题的求解，求解过程中充分考虑了各种几何非线性的影响。

To prepare studying hierarchical intelligent control system of material flows in mineral processing plant further, picturing, transition rulers, analytic methods, relevance matrix and dynamic equation, defect in applying of Petri network, fall short of orient object models applying are discussed after technology of formalization model built, non-formalization built and compound model. And Petri network system with time attribute is expanded opening network system with interface of input and output. The network system expanded with all attributes of basic Petri network model has hierarchy and recursiveness, can be analyzed with mathematical tools of network system and can deal with concurrent and asynchronously also.

为了对选矿厂生产物流递阶智能控制系统的进一步研究奠定基础，本文在讨论了形式化建模技术、非形式化建模技术和复合模型的基础上，研究和分析了Petri网的图形表示、变迁规则、分析方法、关联矩阵与动态方程、Petri网模型应用中的缺陷、面向对象模型应用中的不足，并把采用赋时的Petri网系统扩展成为对外界有输入和输出接口的开放网系统，扩展后的Petri网具有递阶性和递归性，同时保持基本Petri网的所有性质，使模型仍可采用网系统数学工具进行分析，并可处理生产物流系统中的并发性和异步性。

The mathematical model, the simulation model and control model of marine refrigeratory system of 5440TEU container ship are established based on the MATLAB Simulink integrated modeling and simulation environment.

基于MATLAB的Simulink集成建模与仿真环境，针对5440TEU的集装箱船的船舶冷库系统建立了压缩机数学模型、仿真模型及控制模型。

On this basis, according to historical data, apply ANN and differential simulation method to get the quantitatively correlative relations between each production and its own influence factors, and introduce the new methods of prediction for dynamic indexes with gas-field development (The combinatorial prediction method based on fuzzy comprehensive evaluation, the method of ANN to select optimally combinatorial prediction models and the ANN prediction method based on genetic algorithm).(2) Base on mathematical programming, combine with quantitative economics and techno-economics, introduce economical indexes to establish production"s distribution optimal model, production"s constitution optimal model and measured production"s constitution optimal model, including multi-objective models and five-years models. Upon this, the optimal project for all gas field and each gas-collected factory can be got. Also, introduce the time value of capitals to improve on these models.(3) Base on the optimal solution theory and algorithm theory for the nonlinear programming problem, introduce the SUMT algorithm and genetic algorithm to study how to solve the models, and on the basis of normal genetic algorithm, make use of auto-adaptively modulating method to improve on normal genetic algorithm; Base on algorithm"s convergence theory and calculation"s complexity theory to analyze seriatim SUMT algorithm"s convergence and genetic algorithms convergence, and compare performance with each other.

在此基础上，利用神经网络方法和微分模拟方法根据历史数据得到各分项产量与其影响因素之间的定量关联关系，并引入气田开发动态指标新的预测方法(基于模糊综合评判的组合预测方法、神经网络优选组合预测模型预测方法以及基于遗传优化的神经网络预测方法)；(2)以数学规划为基础，结合数量经济学和技术经济学，引入经济指标建立产量分配优化模型、产量构成优化模型、措施产量构成优化模型、气田开发多目标规划模型以及五年规划模型，进而获得全气田及各采气厂的最优方案，并引入资金时间价值对五年规划模型进行改进；(3)以非线性规划问题的最优解及算法理论为基础，引入SUMT算法以及遗传算法对模型的求解进行研究，并在原有的遗传算法基础上，引入自适应调整方法对遗传算法进行改进；以算法的收敛性理论和计算复杂性理论为基础，逐一分析SUMT算法以及遗传算法的收敛性，并比较三种算法的优劣性。

The problem has been studied from two sides, firstly, from the viewpoint of applicability, based on the development strategic objectives of the oil company, with the aim to unify the exploration and extraction decisions of the resources in an integrated framework, and integrate the macro economic and technical objectives with micro economic and technical models of an oil well, an integrated non-linear dynamic optimal control model has been constructed, the objective is the benefit maximum of the exploration and extraction of the resources, and the optimalstrategies are obtained by changing the problem into a non-linear mathematical programming problem, on the other hand, from the more macro level, based on the analysis of the characteristics of the exploration and extraction activities of oil and gas resources, a conclusion is easily deduced that the procedure is full of randomicity, then discovering procedure of oil deposit is proved to be a Poisson process, and the reserves process is a supermartingale process, so the model of exploration discovery rate and the reserves model could be constructed.

其次从相对更宏观的层次上，通过对油气资源勘探与开发的特点分析，认为具有很强的随机性，证明了勘探活动发现油气藏的过程为一泊松过程，所发现的油气藏储量为一上鞅过程，在此基础上，建立了油气藏勘探发现率模型及储量模型，在油气价格服从几何布朗运动条件下，以油气开采收益最大化为目标，建立了一个油气资源勘探与开发的随机最优控制模型，采用动态规划方法得到了值函数的HJB方程，并针对方程的特点，以及方程及其变量所对应的经济学意义，对最优策略的求解进行了一些讨论。

The comparison of results from mathematical model and physical model in vacuum tank for simulation of transient in air cushion surge chamber shows that the similarity laws of various quantities in model test may have influences on the dissimilarity of test results.

本文对比了含气垫式调压室的引水系统，数学模型计算和减压模型试验结果，分析了各种减压模型相似因素对试验结果的影响，认为引水系统管道内含气量、模型的缩尺效应、气室内空气的状态变化以及减压试验条件等的相似性都会造成物理模型试验结果的误差。

Accident tree analysis is applied to risk analysis and a mathematical model is established, including fire model, effective release rate model, heat intensity threshold and hazard area equation.

采用事件树分析法进行风险分析并建立了数学模型，包括火灾模型、有效释放率模型、热强度极限值、危险区域等式四部分。

I want to be a big fish in a small pond.

我要做一条在小池塘里的大鱼。

While the software functioned well, we did not feel the same about their customer support!

虽然该软件运行良好，我们没有同样的感觉他们的客户支持！