地方法

In this paper, the author discusses the theories and methods on making high quality Digital Elevation Model based on terrain feature from digital contour line.

本文全面系统地沦述了基于地性特征建立高质量DEM的理论和方法。

The heuristic method emploies a genetic algorithm in reducing the redundant attributes of all attributes. Besides taking fitness function as its heuristic function for its selection operation, the genetic algorithm uses the attribute\'s information entropy to construct the heuristic function for its mutate operation, and in this way it markedly elevate the convergence speed of attribute reduction.

启发式方法采用遗传算法进行属性约简，除了存在于选择操作的适应度启发函数外，还在变异操作中以信息熵为基础构造了启发函数；穷举方法基于循环队列自底向上约简，通过剪枝有效地提高了属性约简集的穷举速度。

In this paper, based on the analysis of the structure, movement principle and math model of PMSM, fundamental theories of vector control, coordinates transform and algorithm of space vector PWM are introduced and PI control, speed and position calculation methods are discussed.

本论文在分析了PMSM的结构、运动原理及数学模型的基础上，系统地阐述了PMSM交流伺服系统矢量控制的基本原理、坐标变换方法及空间矢量脉冲宽度调制波的生成算法，论述了PI控制算法和速度位置计算方法。

Novel approach for a design-oriented measurement-based fully sealable coplanar waveguide transmission line model.

提出了一种新的基于定向设计测量的建模方法，根据这种方法设计出的最终模型可以方便地在商业设计软件中实现。

A framework for working corporately with related CAD system,finite ele...

利用文中方法可以有效地缩短复杂汽车外形曲面的造型、计算和分析时间，为汽车外形设计的逆向工程应用提供方法和工具。

ABSTRACT To improve the parametric design method which is based on points, lines and circles, this dissertation presents the theory and methodology of parametric design which is based on relating-graph. The expression, organization, cyclic problem, covariation and extension method of relating-graph are studied.

针对当前二维参数化方法中存在的考虑线素较为简单、循环约束问题较难解决等一系列问题，本文系统地研究了基于高层次图素的关联图形的表达、关联图形的组织、关联图形循环约束问题的解决、关联图形的联动以及关联图形的拓广等方法。

It provided a correct and reasonable mathematical model for the analysis of the ultimate bearing capacity and crankle stability of the thin-walled structure.

论文在比较了两种运动描述方法（完全拉格朗日法和更新拉格朗日法）异同点并分析了非线性几何关系及大变形下的弹性物理关系的基础上，基于增量虚功原理推导了几何非线性空间梁元单元切线刚度矩阵，采取分模块形式，分别表示了轴力、弯矩、双力矩对几何矩阵的贡献；通过球面显式荷载增量迭代式弧长法求解方法编制程序，很好地实现了几何非线性增量荷载的自动步长选择及全过程跟踪，为薄壁杆系结构的极限承载力分析和弯扭失稳分析，提供了较为精确合理的分析力学模型。

By using this method, the angular frequency, amplitude, initial phase angle, decay constant of each component in transient voltage and/or current waveforms can be precisely extracted. Also, all other kinds of transient procedure can be analyzed by this method. Thirdly, a new definition of generalized instantaneous reactive power and generalized instantaneous reactive current in dq0 coordinates under any nonsinusoidal and unbalanced three-phase circuit is proposed for the first time. The detection and compensation method for different instantaneous reactive currents are also concerned.

本文首先提出了用于快速高精度频谱分析的一种改进快速傅立叶变换方法，该法具有速度快、精度高、抗混迭、不受采样定理约束、可以分析出谐次大于N／2的频谱系数等特点，可方便地应用于电力系统谐波分析及其它各类频谱分析；然后提出了基于非线性最小二乘优化法的电力系统暂态波形分析方法，可准确求出电力系统暂态电压、电流波形中各个分量的角频率、幅值、初相角及衰减常数，并可广泛应用于各类暂态过程波形分析。

Cussed above, I firmly believe that time will prove that traditional technology and methods would die out with the development of modern science and technology.

通过以上讨论，我坚定地相信时间会证明传统技术方法将会随着现代技术的发展而消亡，坚持传统技术方法是徒劳的。

Based on mathematical mechanization method and computer symbolic processing technique this paper carried out a solution by symbolic method for position analysis of robot with octahedral and decahedral variable greometry truss.

基于数学机械化方法和计算机符号处理技术，对八面体及十面体变几何桁架机器人的位置分析进行了符号法求解，成功地将非线性位置约束方程组化简为等价的三角化方程组，分别导出了单变量的16次和48次代数方程，并给出一个数字实例说明这种方法。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。