查询词典 method study

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

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。

The project was based on the influence to the asphalt mixture volumectric property by the different compaction method (Marshall Compaction, Roller Compaction, Gyratory Compaction, Vibratory Compaction), a great deal of the experiments has been done with the consideration of the pratical construction. A lot of studies were carried out, such as the study of asphalt mixture image inquiring technique--"Colour Method", the feasibility study of the application of the 2D digital image processing technique on the asphalt mixture and the utiliztion of this technique on the compacting properties analysis of asphalt mixtures. A good beginning and foundation was made for the application of the digital image processing method on the study of the 3D asphalt mixture voluemetric components constitute.

本项目以研究不同沥青混合料成型方法（马歇尔击实、轮碾压实、旋转压实、振动压实）对沥青混合料体积特性的影响作为切入点，结合实际工程，进行了大量试验，开展了&色彩法&沥青混合料图像获取技术研究、沥青混合料二维数字图像处理技术的可行性研究以及采用该技术分析沥青混合料压实特性等研究工作，取得了一系列研究成果，为采用数字图像处理技术解决三维沥青混合料体积组成特性开创了良好的开端，奠定了坚实的基础。

In the paper, we mostly studied the change of soil erosion process by a new REE tracer method, based on the theories of hydraulic mechanical subject and radionuclear tracer method, and simulated rainfall was applied to study the sheet erosion changing to rill erosion and the rill erosion process on slope land. The new REE tracer method should be useful to future studying of erosion processes on slope lands.1. Offering and testifying a new REE displacing method to study on the soil erosion of the loess slope.

本文以黄土坡面土壤侵蚀形态演变规律为研究重点，以新的核素示踪技术为手段，采用水动力学与核素示踪技术相结合、室内人工模拟降雨与稳定性REE元素示踪相结合的方法，利用先进的INAA技术，定量研究了不同雨强次降雨条件下细沟间侵蚀向细沟侵蚀的转变过程、细沟发生发育过程，为深入了解坡面侵蚀过程，建立黄土高原土壤侵蚀预报模型提供了研究基础。

Basic Study on Erection Planning Method for Beam String Structure 2,Study on Structural Characteristic of Hybrid Skeleton with Tension Strings 3, Proposal of Reversed Progress Teclmique for Tension Structures and Its Application 4,Mechanical Behavior of Hybrid Skeleton with Tension String during Construction 5,Experimental Studies on Structurel Characteristic of Hybrid Skeleton with Tension Strings 6,Mechanical analysis of a type hybrid spatiaI structure composed of cables,bars and beams 7, Tensile force compensation analysis method and application in construction for hybrid structures 8,Tensile forces emulationaI analysis of prestressed cables for multistage tension construction method 9,Reverse analysis method of construction centrel tensile force for prestressed space structures

1 ，基础研究规划方法架设张弦梁结构 2 ，结构特征研究混合骨架张力弦 3 ，建议反进展Teclmique张力结构及其应用 4 ，力学性能的混合骨架张力字符串施工 5 ，实验研究Structurel特征混合骨架张力弦 6 ，机械分析型杂交spatiaI结构组成的电缆，酒吧和梁 7 ，张力补偿的分析方法及应用在建筑混合结构 8 ，拉伸部队emulationaI分析的多级预应力锚索张拉施工方法 9 ，逆向分析方法的建设centrel张力的预应力空间结构

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。

In this paper, based on the study of various methods calculating the risk occurrence probability, a new method TAA method was obtained, which was the combination of improved TOPSIS method, AHP method and ANN. This new method was used into the invest risk analysis of 019 project and calculation were carried out on the related invest risk occurrence probability caused by all kinds of risk factors.

本文在对各种风险发生概率计算方法的研究基础上，通过将改进的TOPSIS法、AHP法和神经网络相结合得到一种新的风险发生概率计算方法——TAA方法，并将其应用于019工程的风险分析中，对由各风险因素所引发的019工程风险的发生概率进行了计算。

In this chapter, through the analysis of"the method Elchataym"and"the method tree", the study of the problems in chapter thirteen in Liber Abaci, and the comparison of"the method of Excess and Deficit"in Chinese mathematics, it argues that"the method Elchataym"is not equal to"the method of Excess and Deficit", and statement that"Elchataym"is"Khitan"lacks convincing support.

本论文通过对&Elchataym算法&、&树方法&算理分析、对第十三章所有算题系统研究、以及将&Elchataym算法&、&树方法&和中算之&盈不足术&比较之后认为：&Elchataym算法&不完全等同于&盈不足术&，而且认为&Elchataym&就是&契丹&的音译缺少令人信服的支持。

At first, the wind tunnel test and test data process of this study are introduced in detail. A method to calculate expected extreme values of time series with a long time interval is then proposed with its sub-sections based on the classical Gumbel theory for extreme values and the independence of observed extreme values. At last, the extreme values of the wind pressure coefficients of the present wind tunnel test are calculated with the proposed method and methods used widely at present, such as peak factor method, improved peak factor method and Sadek-Simiu method.

首先 介绍了风洞试验及试验数据处理的基本概况；然后在阐述经典Gumbel极值理论的基础上，根据观察极值的相互独立性推导了短时距下极值分布参数和长时距下极值分布参数的关系式，给出了一种由短时距样本推算长时距下的极值估算方法；最后基于风洞试验数据，将常用极值估算方法(峰值因子法、改进峰值因子法和Sadek-Simiu法)和该方法的计算结果进行了比较。

The description methods of natural scenery was studied based on fractal, that is, recursive method, L-system method, IFS and IFS description method was put forward based on sine or cosine. This method overcomes angularity and consistency of recursive method, L-system method and IFS, and the variety of fractal sculpting consequence can be added and the basis for the later research and the application was provided.

对基于分形的描述自然景物方法，即递归洪、L-系统法、IFS法进行了分析研究，在此基础上，提出基于正余弦的IFS描述法，该方法克服了递归法、L-系统法、IFS法等描述方法的生硬性和一律性，增加了分形造型结果的多样性，为以后的深入研究和应用提供了依据。

Continuously improve the production mechanism, to provide customers with better quality products and services.

不断的完善生产机制，给客户提供更优质的产品及服务。

B:Yes, he was the very prize-winner in the court tennis ten years ago?

是的，他是十年前的世界网球冠军。