查询词典 numerical method

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 main contents of this course include: introduction, extraction of root from an equation, numerical solution of a system of linear equations, interpolation method, the method of fitting of a curve, numerical integration and differentiation, numerical solution of a differential equation, one-dimensional search method of extreme value problem, etc.

本课程包括以下内容：绪论、方程求根、线性方程组数值解法、插值法、曲线拟合法、数值积分与数值微分、微分方程数值解法、极值问题的一维搜索法。

The classical cutting stock algorithm——column generation technology , and wrap up rectangle technology for abnormity are analyzed ; The development of AutoCAD with ObjectARX is studied and the generating method of cutting outline drawing and layout drawing were found out on the basis of analyses of the graph database structure of AutoCAD and the basic operation of it ; The process planning technology of plate material cutting orienting numerical control is studied a process planning method directly based on layout drawing is established ; The emulation technology in AutoCAD is studied and a kind of dynamic emulation method is put forward , which is realized by incrementally modifying graph entity ; The postposition of NC program of the integrated cutting system constructed on software plug-in is proposed , which can effectively solve the problem that it is difficult for a numerical control programming system to be common , which is caused by the difference of instruction format and control parameter between different type of numerical control machine .

分析了经典的矩形件优化排样算法——列生成法和针对异形件的矩形包络算法；研究了基于ObjectARX 的AutoCAD 开发技术，结合对AutoCAD 图形数据库结构及其基本操作的分析，给出了下料轮廓图和排样图的生成方法；研究了板材数控下料加工的工艺处理技术，建立了一种直接基于排样图进行的图形交互工艺规划方法；研究了在AutoCAD环境中的板材下料数控仿真技术，给出一种通过增量修改图形实体对象实现的动态仿真方法；提出以软插件技术构建集成下料系统的数控编程后置处理部分，能够有效解决因数控下料机床指令格式及控制参数不统一导致的自动编程软件系统不易实现通用性的问题。

With understanding the numerical control milling machine in cam processing utilization, thus people can complete analysis of the discoidal cam numerical control mill technological capability , the programming and the analysis of grooved cam numerical control mill technological capability, the compilation of numerical control processing technological document.

了解数控铣床在凸轮加工中的运用从而完成盘形凸轮数控铣工艺性分析及程序编制和槽形凸轮数控铣工艺性分析及编写数控加工工艺文件。

Every industrialized country lists the numerical control technology and numerical control equipment as country's critical materials besides in the world, not only come to develop self numerical control technology and their estate adopting an important measure, and the effectuation blockades and restricts policy in the respect of the numerical control key technology and equipment "high-grade , precise , and advanced" to our country

此外世界上各工业发达国家还将数控技术及数控装备列为国家的战略物资，不仅采取重大措施来发展自己的数控技术及其产业，而且在"高精尖"数控关键技术和装备方面对我国实行封锁和限制政策

The development direction changed direction according to the four-wheeler, the domestic and international company changes direction organization to control to the four-wheeler currently main adoption of is a numeral control, this is owing to a lot of advantages of numerical control:the procedure turn a control, the controller carries on the processing of operation and numerical information according to the control regulation designed, mainly passing procedure to carry out, if change control regulation need to change software, but need not change the hardware structure of system: control the accuracy is high, in the emulation the control the system, the accuracy of the controller from the accuracy of the component but settle, numerical controller accuracy from word long decision;Stability good;The software replies to use, needing a hardware environment of using the homology realization in the emulation the system, the numerical controller is a procedure control, the sub- procedure mold piece which need to be designed and write to carry out its model, can immediately carry out several links of functions expediently.

目前各个厂家大多采用的是PLC、单片机应用于四轮转向控制器中，功能基本能够实现，相比较之下，信号处理能力较强的数字信号处理器各方面均性能优于以上三种处理器。DSP是新世纪数字化革命的核心。它是一种独特的微处理器，具有可编程性，且实时运行速度远远超过通用微处理器。强大的数据处理能力和高速的运行速度，是DSP最值得称道的两大特色。DSP芯片是一种特别适合进行数字信号处理的微处理器。它强调运算处理的实时性，因此除了具备普通微处理器所强调的高速运算和控制功能外，主要针对实时数字信号处理，在处理器结构、指令系统和数据流程上做了很大的改动。它具有灵活、精确、可靠性好、体积小、功耗低和易于大规模集成等优点。

This paper analyzes the numerical control DC constant current source system design needs, expounded numerical-controlled DC constant current source of the hardware and software design principles, instructed the numerical-controlled DC constant current source circuit of the module function and design ideas, completed the numerical-controlled DC current source of all design, and the circuit is complete and procedures.

本文主要分析了数控直流恒流源系统的设计需求，阐述了数控直流恒流源的软硬件的设计原则，介绍了数控直流恒流源各模块电路的功能及设计思路，完成了数控直流恒流源系统的全部设计，给出了完整的电路图和程序。

But in the numerical calculation process, such as numerical differentiation, if we use these numerical methods inadequately, then it may be induced non necessary numerical error, including round off and truncation error.

因而常必须以值方法替代解析解，但是在值计算的过程中，很容引入额外的计算误差，包括舍位误差与截断误差。

In chapter5, the serial properties of numerical range of operator polynomial are put firstly. Secondly, the relation between numerical range of operator polynomial and n-numerical range are considered. Thirdly, in the light of matrix norm, matrix singular value, the regions and bounds of numerical range and spectrum of operator polynomial are dicussed carefully.

第五章研究了算子多项式数值域的性质、算子多项式数值域与n-次数值域的关系，特别地利用矩阵范数、矩阵的奇异值、非负矩阵的理论、友矩阵为工具，给出了算子多项式数值域及谱的范围全面刻画，并深刻地研究了算子线性束的正则性的等价条件及谱分布。

The company is in line with " the product has no limits, the principle that based on sincerity and pursue being outstanding ", invest the numerical control woodworking machinery trade meticulously, besides researching and developing the products that numerical control woodwork engraves the milling machine , numerical control and carves the milling machine , three major series and a dozen specifications of numerical control carving machine, having developed 10 axle cantilever woodwork machining centers again recently, the real wooden door, special-purpose bull of wave board engraved the milling machine , changed a one hundred sheets of woodwork and engraved the milling machine automatically, multicipital workingbench movement woodwork engraves professional equipment , such as milling machine ,etc..

公司本着&品无止境，诚信为本，追求卓越&的原则，精心投入数控木工机械行业，除研发出数控木工镂铣机、数控雕铣机、数控雕刻机三大系列十几个规格的产品外，近期又研制了10轴悬臂木工加工中心，实木门、波浪板专用多头镂铣机、自动换刀木工镂铣机，多头工作台运动木工镂铣机等专业设备。

This paper put its emphases on research of its structure designing and kinematics analysis.

本论文着重研究scara 机器人的结构设计和运动学分析。

The sensitivity of CEA by immunofluorescence examination and LSCM is useful for the diagnosis,differential diagnosis of meningeal carcinomatosis.

联合应用免疫荧光细胞化学法和LSCM检测脑脊液细胞中CEA的表达可为脑膜癌病的诊断提供可靠依据。