查询词典 parameter equation

By using the orthogonality condition of augmented eigeuvector of multibody system, the algebraic equation group with unknowns of structure parameter is formed.

利用多体系统增广特征矢量的正交性条件，可建立以系统物理参数为未知数的代数方程组。

The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.

文中对汽车碰撞安全性的设计理论和方法进行了归类和总结，其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等；重点介绍了碰撞有限元法的基本理论和有关算法，涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等，探讨了有限元计算中的材料模型参数获取技术，开发了相应的材料试验装置及材料模型参数反求软件，在此基础上进行了基本的碰撞仿真算例和试验对比研究；文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性，指出了设计薄壁吸能构件时需要考虑的几个主要影响因素，即焊点、壁厚、横截面和预变形等；在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究，提出了吸能转向机构和自适应安全气囊的仿真研究方法；文中最后探讨了整车碰撞性能的设计与改进方法，提出了以理想碰撞特性为目标，采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法，并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究，所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车，研究结果表明，本文所提出的设计与改进方法是适用而有效的，具有重要的工程实用意义和价值。

In this thesis, we take the delay r as a bifurcation parameter to investigate the Hopf bifurcation phenomenon in system (1). By analyzing the associated characteristic transcendental equation of system (2), and using the Hopf bifurcation theorem, we obtain one condition for the existence of Hopf bifurcation in system (1). Furthermore, based on the center manifold theorem and the method of normal form, some interesting results about the properties of Hopf bifurcation are obtained, including the direction of Hopf bifurcation and stability of Hopf bifurcating periodic solutions.

我们以时滞T作为分支参数，研究了系统(1)的Hopf分支现象：通过分析系统(2)的特征超越方程，结合利用Hopf分支定理获得了系统(1)的Hopf分支存在的一个条件；利用中心流形定理和正规形方法分析了系统(1)的Hopf分支的性质，包括分支的方向和分支周期解的稳定性。

Choosing time delay as the control parameter, the stability of trivial equilibrium is discussed by analyzing distribution of the roots of the associated characteristic equation. It is found that Hopf bifurcation occurs from trivial equilibrium when the delay passes through critical values, then the critical values and their relations with system control parameters are obtained.

以时滞量为参数，通过分析对应线性系统特征方程的根的分布，讨论了平凡解的稳定性，得到了平凡解发生Hopf分岔而失稳的临界时滞量以及临界时滞量与系统控制参数的关系。

Hydraulic turbines ; silt-laden water flow ; two phase flow ; Bernoulli equation ; operating parameter

水轮机；含沙水流；二相流动；伯努利方程；工作参数

The evaluation method and physics meaning of every parameter in the viscosity relationship equation were elaborated using theologic experiment data, and the viscosity relationship equation be referred to in the literature were appraised using simulate data and experiment data.

利用聚甲基丙烯酸甲酯乳胶体系的流变数据，阐述该粘度关系方程式中各参数的求值方法及其物理含义。同时也用数值模拟数据以及实验数据，评价了文献中所提到的粘度方程。

In chapter3, information is divided into two basic types, the marginal equation of bond price and short-term interest variations is established, thus the security price variations and the price equilibrium of other assets (risk security non-risk security are included) are analyzed by the implement of portfolio Theory. Finally the bond value equation which takes equilibrium return as its yield Parameter is established through the theory of comparative return. In chapter 4, the intra-information and the transferable system of price is emphasized and the market-maker model and expected model under non-perfect information market conditions are established, and the disaccord of the influence of extra-information and intra-information on the security price is discussed.

第三章将债券的价格均衡划分为两大基本类型，建立了债券与短期利率变动的边际方程，运用组合原理分析债券价格变动与其它资产(包括风险证券和无风险证券)的价格均衡关系，通过比较收益原理建立了债券以市场均衡收益为折现参数的价值方程，并通过实证检验了该模型的合理性；第四章，分析了内部信息与价格的传导原理，建立了非完全信息市场条件下价格传递信息的做市商模型和预期模型，并讨论外部信息与内部信息对股票价格影响的非一致性。

The model adopts continuity equation, diffuse wave model, and the Mannings equation for surface runoff routing, while uses the Green and Ampt infiltration theory and Darcys Law for subsurface runoff treatment. Uncertainty analysis incorporating Monte Carlo simulation and a Maximum Likelihood Estimation and Efficiency Coefficient is used to retrieve optimal parameter values and to estimate the confidence interval for the simulation results.

目前已经完成模式中各相关模组的研发，包含利用DEMs 析取坡度、流向与集流面积；利用卫星影像评估土地利用类别；结合蒙地卡罗法、最大概似法与效率系数的参数率定器；以及整合Green and Ampt 的入渗理论、Manning 地表流速公式，Darey 定律和扩散波理论的水文演算模组。

In order to better analyze the change of China economy under CAFTA, author separated Asean from other countries in the world. Author makes up the SAM of China 2000, re-estimate the parameter of produce equation, consumed equation, and substitute flexibility etc. By mean of analyzing its policy significance, author put forward to some proposals at last.

重新编制 2000年我国社会经济核算矩阵表，估计了三部门的生产函数、居民消费函数、进出口替代弹性等参数，重点模拟这种贸易合作安排对我国未来经济发展可能产生变化的影响，通过分析其中的经济含义，最后提出相应的对策建议。

Methodological analysis is based on pulse wave to conduct the principle of blood pressure of time computation artery, put forward pulse wave to conduct the relation equation of time and blood pressure, discussed method of equation parameter demarcate.

方法分析基于脉搏波传导时间计算动脉血压的原理，提出脉搏波传导时间和血压的关系方程，并论述了方程参数标定方法。

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。