坐标系统

This article focuses on the line-line, line-region and region-region topological relations algorithm, which come down to the same question: whether there are intersections between line and line. The sweep-line algorithm was studied by many people, but has some deficiencies to be improved, in order to handle some special cases and increase program efficiency. My works as follows: rectangular envelope to reduce executive times , vector cross multiplication to determine intersection between line and line, coordinates and slope method to deal with some special cases. C program examples are showed together.(5) Finally, to prove capability and efficiency of the model and calculation method, some test systems are developed. For example, complex spatial topological relation query, parcels' exact area with the area of linear object reduced in land use, quality inspection to cadastral data according to topological rule, spatio-temporal change query of cadastral data.

将线线、线面、面面之间的拓扑关系实现的算法归结为线与线之间求交的基本问题；为处理一些特殊的拓扑关系情况，提高扫描线算法的效率，探讨了包络矩形粗滤、判断线线是否相交的矢量叉乘法、线节点重合或共线的斜率坐标判断法等改进方法；同时还设计了一种新的节点微小圆求交的算法，可应用于图斑与线状地物细分拓扑关系及地类面积的计算；（5）本文设计了实验系统，包括复杂对象的拓扑关系表达与计算程序、图斑地类面积的计算程序、基于空间拓扑关系规则的地籍数据库质量检查功能，以及时空拓扑关系和变化语义分析等原型，验证了拓扑关系表达模型和计算方法的可行性和实用性。

A map will show you the current, approximate GPS coordinates for your iPhone.

地图将显示您当前，全球定位系统坐标近似为你的iPhone中。

Mathematics Any of a set of two or more numbers used to determine the position of a point, line, curve, or plane in a space of a given dimension with respect to a system of lines or other fixed reference.

坐标：由两个或多个数值组成的数组中的任一数值，用来在一个直线系统或其它固定参照数值方面决定点、直线、曲线或平面在已知范围空间内的位置

An optical system with refraction and total internal reflection was proposed according to the luminous characteristic of LED and the law of energy conservation. The ordinary differential equations satisfying the spots on the contour curve of TIR refractive and reflective planes were established. The coordinates of points on profile curves were obtained by solving these ordinary differential equations using Runge-Kutta method. The profile curves were acquired by curve fitting of the coordinate spots with software UG, and then TIR model of the projector and data of the surface shape suitable for NC manufacture were obtained.

根据LED的发光特性以及能量守恒定律选择采用折射全反射光学系统，通过建立TIR折射面及全反射面轮廓曲线上的点所满足的常微分方程，利用RungeKutta求解常微分方程得到轮廓曲线上点的坐标，再在UG中对坐标点进行曲线拟合得到轮廓曲线，进而得到TIR模型及适合数控加工的面形数据。

Making use of the space vector method, this article sets up two coordinate numeric control grinding motion model of elliptic taper piston, and researches on the law of error compensation for the systematic motion after dressing grinding wheel.

用空间矢量方法建立了椭圆锥体活塞的两坐标数控磨削运动模型，研究了砂轮修整后应对系统运动进行的误差补偿规律。

A motion reference coordinate system of this quadruped robot and its simplified-structure of the multi-rigid body dynamics model are established. After kinematic and dynamic analysis, the kinematic equation, inverse kinematic equation and Jacobi matrix of the quadruped robot are presented, and the second kind of Lagrange dynamic equation group for simplified-structure of the quadruped robots multi-rigid body system is educed.

建立了该机器人的运动坐标体系，及其等效简化结构的多刚体动力学模型，对上述模型进行了运动学和动力学分析，给出了该机器人的运动学、逆运动学方程和雅可比矩阵，并导出了其简化结构多刚体系统的第二类Lagrange动力学方程组。

Grasp and understand terminologies and concepts of Engineering Thermodynamics, such as thermodynamic system, state property, equilibrium state, state properties diagram, equation of state, quasi-static process and reversible process, etc.

理解和掌握工程热力学中的一些术语和概念：热力学系统、状态参数、平衡状态、状态参数坐标图、状态方程式、准静态过程、可逆过程等。

Meanwhile, by means of generalized transform method, its two-phase equivalent circuit, impedance transformation and nodal admittance matrix in phase coordinates are given in order to analyze and calculate the problems related to the terminals connecting power grid with traction power network.

同时借助端口电气量的一般变换方法，给出了YNvd接线变压器两相等值电路、阻抗变换以及相坐标下的节点导纳矩阵，以便分析和计算与电力系统和牵引网端口有关的问题。

Time is one of the basic physical attributes of the world we live in. The accurate time not only gives an essential parameter to science research and experiments and engineering technologies, but works as an indispensably ruler for all dynamics systems and sequential procedure.

时间是物质运动和存在的基本属性之一，精密的时间作为科学研究、科学实验和工程技术诸方面的基本物理参量，为一切动力学系统和时序过程的测量和定量研究提供了必不可少的时基坐标。

Using the ESG with eight electrodes, the paper gave the formulas of electrode capacitances, introduced the detection and solution of rotor motion, and then deduced the formulas of electric field forces.

八电极静电支承系统沿着四个非正交轴对转子施加静电力，这些作用力相互影响，因此需要对支承坐标进行垂直解耦。

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。