面向数字城市规划的城市规划模型研究

作为面向数字城市规划的关键技术,地理信息系统技术、遥感技术支撑下的城市规划模型的研究已经成为城市规划领域的热点问题之一。根据规划模型研究的对象和目的的不同,提出将城市规划模型分为综合规划模型和工程专项规划模型,按照这种分类方式这两种模型的研究进展进行了简要的介绍,并对其研究趋势与研究对策进行了分析。     

一种三维编织物表面参数自动测量方法

提出一种三维编织物表面参数的自动测量方法．这种方法是利用图像设备把三维编织物表面图像输入到计算机中，利用图像处理技术对其纹理特征进行处理，文中给出了算法并编程实现，也给出了一组具体的测量结果．     

基于DDS技术的高性能雷达信号源的设计

直接数字频率合成(DDS)技术在带宽、频率转换速率、调频线性度、频率分辨率等方面有优异的性能,被广泛应用于脉冲压缩雷达系统中。采用AD公司最新的直接数字频率合成芯片AD9954来设计高性能雷达信号源以产生线性调频信号,通过PC机来控制波形参数,输出频率范围为1MHz～160MHz,扫频带宽可达100MHz,扫频时间在0.05ms～1ms之间,信噪比优于70dB,能够满足高频地波雷达的需求。     

面向考古应用的自然语言查询系统的设计实现

针对当前研究的热点问题———界面层自然语言理解的应用,设计和研制了一个面向对象的受限汉语自然语言数据库查询系统DMNLQ。该系统针对特定的考古数字博物馆应用,提出了受限汉语的上下文无关文法,把查询语句通过定义的文法进行标注,并采用语义树的形式进行表示。系统还提出了一种中间形式语言MML对语义树进行描述,运用关联路径搜索策略解决了查询中比较复杂的表间相互联系的表述问题,从而实现了从MML到SQL语句的转换。     

Digital Mock-up Technology in Product Development and Research

1 Introduction Digital mock-up(DMU)technologyis a set of integratedtechnologies built onthe application of informationtechnology throughout the complete product development process .Based onthe computer model of digital prod-ucts ,Engineers can do their design works fromthe first stage of product designtoindustrial design and processplan design. The three-di mensional mathematical models replace the original physical prototype in the digitalmode si mulation,and check the original design or i…     

The Technology of Individual and Digital Pattern-making in the MTM System

The Garment MTM enables to realize the individual and quick manufacture to meet the development of the per- fectly popular and various garment industry,whose core technology is to produce the individual and digital pattern,that is,get- ting the individual pattern-making according to the body information.It is relatively correct and wise to get the individual pattern by modifying the basic pattern and the experts in this field do their researches on this way.One vital and unsolved problem is that how to find the very pattern which is the closest to the customers in the pattern-database which determines the validity of the final pattern.We conclude a technology methods from body information to digital pattern,design the rule of seeking yards and pattern- modification,build the B-P system (the system of the quick manufacture technology of body information-digital pattern),set up the style database,yarn database,pattern database,the rule databases of seeking yards and pattern-modification.It is confirmed that the B-P system is available,the setting-up of all the databases in the system is reasonable and the final pattern is correct.     

Digital Manufacture Techniques for Large Hydro Turbine's Blades

Blades are one of the vital components and most difficulty in manufacturing of large hydro turbines.In order to cost-effectively and productively manufacture these kinds of blades,a series of digital techniques in manufacturing have been devel- oped,which includes digital design of hydro turbine blades based on manufacture' requirements,Computer-aided location and the machined error evaluation by using 3-dimensional digitized measuring,tool path generation strategy to meet requirements of en- hancing machining efficiency and controlling deviation in NC machining,tool path generation and NC machining simulation by es- tablishing a virtual NC machining environment for blades,and reasonable and feasible strategy and the systematic scheme for man- ufacturing of large blades by using 5-axis simultaneous CNC machining.The developed digital manufacture techniques have been successfully applied in manufacturing of both the large Kaplan and Francis hydraulic turbine blades;it shows that higher efficiency and the better surfaces finish accuracy can be achieved.     

Development of a Reconfigurable Platform for Manufacturing Equipment Control

In modern manufacturing equipment control area,controller is required to deliver higher computing capability for adopting advanced algorithms to meet speed and accuracy requirements,and reconfigurabilities for changing or(and)adding features or functions.This paper presents a methodology in design and implementation of a high performance and reconfigurable platform for manufacturing equipment control.This methodology is in virtue of system on a programmable chip(SoPC)technolo- gy but replacing the on-chip processor by an external high performance,floating-point digital signal processor(DSP).The appli- cation of the DSP is designed as a multi-threaded framework,which has more flexibilities than a traditional single-loop one.Fur- thermore,the field programmable gate array(FPGA)system can be reconfigured easily and quickly to meet a new requirement by dragging and dropping pre-built components in a SoPC building environment.As a result,the controller platform is more recon- figurable in terms of algorithms and functions.This platform is implemented in a 3-axis milling machine control and the result indicates that the design and implementation presented in this paper is feasible.     

Design of Digital Control System for Cement Raw Material Preparation

This paper describes the design of cement raw material prepared digital control system by PROFIBUS. It uses the digital technology to implement the digital control system for raw material prepared of the cement factory. This system improves the communication between the industrial system and locale instrument devices. It applies digital communication to replace the 4-20 mA or 24VDC signal between locale lever device and controller.     

燃油电厂黑启动初期励磁涌流的数字仿真和试验研究

具有自启动能力的燃油电厂在广东地方电网黑启动中承担重要角色,但这些电厂常常在空充主变时受励磁涌流冲击而导致黑启动失败。电厂负荷和发电机控制系统的复杂性限制了精确解析方法在励磁涌流研究中的应用。该文利用电磁暂态仿真软件搭建了详细的燃油电厂模型,研究了黑启动初期励磁涌流对发电机稳定运行的影响及减少励磁涌流冲击的措施,其研究结论在现场试验中得以成功应用。