基于三相逆变SPWM调制的DSP代码自动生成

本文以实现SPWM调制策略为例,利用Embedded Target for TIC2000 DSP模块(以下简称ETTIC2000模块)结合Simulink库中自带的模块进行DSP的C代码自动生成,提出了SPWM在DSP程序开发上的新途径。实验结果表明生成的代码在TMS320LF2407A处理器上运行正确。     

基于直接序列扩频的电机车架线载波通信系统

对电机车架线载波通信系统采用以STEL-2000A直接序列扩频芯片为核心的硬件系统设计方案,着重介绍系统的硬件实现和主控制模块的软件流程。实验表明了扩频技术在该载波通信系统中的可行性。     

Local Bifurcations of Control-Affine Systems in the Plane

The phase portrait of a control-affine system, being an almost complete feedback invariant, carries the information on time-optimality and controllability structure of the system. In the paper, we deal with generic control affine systems and 1-parameter families of such systems around stationary points of their controllable part. We classify the portraits of such systems up to homeomorphisms of the state space. In the case of 1-parameter families, the classification embraces bifurcations, which can appear when changing the parameter. The figures illustrating these phenomena are included. The work was partially supported by the European Community Marie Curie Fellowship (in the CTS framework), contract number: HPMT-CT-2001-00278 and KBN grant 2P03A00124.     

Excel 2000软件在耕地储备台账、统计工作中的运用

本文论述Excel 2 0 0 0软件在建立耕地储备台账中的运用方法。Excel 2 0 0 0软件 ,在未开发耕地储备台账数据库软件的情况下 ,利用Excel 2 0 0 0软件建立数据库来完成县、市、省、部四级的年度统计工作     

外部参数文件在AutoLISP程序设计中的应用

研究了基于AutoCAD2 0 0 0平台 ,用AutoLISP语言编程实现与外部数据连接的方法 ,讲述了在AutoLISP程序设计中使用外部数据文件的方法。     

法兰制造厂申请PED/AD2000-W0认证的关键技术要求

国内法兰锻造厂在申请承压设备指令PED 97/23/EC/AD2000-W0认证的过程中,普遍存在技术储备不足,对规范要求不够了解等情况。本文依据PED指令及AD规范对法兰用典型材料如S235JRG2(碳钢)、1.4301和1.4401(不锈钢)的认证技术要求,从执行标准、检验组别、试验要求、化学成分含量以及力学性能要求等方面进行了归纳总结。为企业顺利通过认证,编制相关的程序文件和作业指导书提供了指南和索引,对提高企业产品质量、增强竞争力,从而提高开拓欧盟产品市场的竞争力。     

Wild City: MVRDV - Weaving Nature and the Urban

Architect Marta Pozo Gil , who leads the Sustainability Department at MVRDV, draws on a correlation between people's retreat indoors, with urban populations becoming increasingly divorced from nature, and the growing ambitions for ‘green’ cities and the ensuing benefits they bring to our quality of life. How might it, though, be possible to realise such a vision? Pozo Gil describes some of MVRDV's lesser-known projects that weave nature into the city.     

Efficient sub-band coding in JPEG2000 for improved authentication and tamper-proofing

Abstract

The LL sub-band from the discrete wavelet transform in JPEG2000 is similar to a smaller image of the original in spatial domain. The proposed authentication and tamperproofing scheme is to extract and hide the entire LL sub-band into the first-level sub-bands, 1LH and 1HL. The hidden data are used later with a unique digital signature and a public key to prove the authenticity of the image. Tampered areas could be accurately detected and recovered to a quality that is visually acceptable. This scheme can be used to authenticate sensitive images, such as medical images, to prove rightful ownership and to recover images before originals are available.     

剪力墙下桩独立筏形承台基础设计与分析

随着高层建筑的日益增多,各种基础形式应运而生,高层建筑基础选型是整个结构设计的重要组成部分之一,直接关系到工程造价.剪力墙下独立桩筏形承台(墙下局部筏形基础)以其优越的经济性开始应用于高层基础.工程设计中,<建筑地基基础设计规范>对T形、L形剪力墙下桩筏形独立承台的计算并未作规定.将对T形、L形剪力墙肢下独立桩筏形承台...     

上海市低潮高地及暗礁测绘技术设计概要

本文对上海市低潮高地及暗礁测绘项目技术设计进行了总体阐述,介绍了项目技术难点、采用的主要技术指标,对测量基准传递、陆域测量、海域测量、暗礁测绘的技术思路进行了归纳总结,实施方案主要包括:GNSS控制测量、高程系统跨海传递、无人机航测和机载激光雷达测量、GNSS RTK无验潮水下地形测量、多波束岛礁测绘、无人船测量等,对项目实施技术要点进行了说明,指出了项目实施过程中需要解决的问题,期望为同类项目实施提供参考。