The extensible markup language ( xml ) is a promising standard for describing semi - structured information and contents in the e - business . when xml comes to be a widespread data encoding format for web applications , safeguarding the accuracy of the information represented in xml documents will be indispensable Xml在描述电子商务中的半结构化信息及内容时具有很好的前景,但当xml成为web应用中广泛使用的编码方式时,保证xml描述信息的安全性是必不可少的。
An idea is brought forth to design the total structure of the usb interface ip , the main control logic , the mcu interface ( the function is the same as the pdiusbd12 chip of the philips semiconductor ) and a dpll which is used to synchronize data and separate the clock . this paper also introduces packet recognition , transaction sequencing , sop , eop , reset , resume signal detection / generation , nrzi data encoding / decoding and bit - stuffing , crc generation and checking ( token and data ) , packet id ( pid ) generation and checking / decoding , 提出设计了usb接口电路的整体构架,设计了usb的主要控制逻辑和与mcu的互连的接口(此接口与飞利普的usb接口芯片pdiusbd12兼容) ,也设计了一个数字锁相环( dpll )来同步数据和分离时钟,并对同步模式的识别、并行/串行转换、位填充/解除填充、 crc校验/产生、 pid校验/产生、地址识别和握手评估/产生做了具体的分析。
The focus of this thesis is on the introduction of the software architecture of the new system , including selecting the appropriate development flat , pc communicating principle , its own software modules and the respective functioning principles of the related parts . besides , some modules are offered such as a universal data encoding and decoding module , a power management module and a remote monitoring module 然后,对基于m - bus的水表联网抄表系统的软件构成包括开发平台的选择、 pc通讯机制、系统的模块组成和相关部分的实现原理进行了重点的描述,给出了一个通用的数据加密、解密模块,权限管理模块和远程监控模块。
Differential gps has become the prime and essential positioning system for many applications . this paper introduces the principles of the differential global position systems . clarifies the arithmetic of the pseudo - range dgps . by the high - class differential reference station receiver called javad receiver which being used in our laboratory now , some necessary work has been done : data digging from javad receiver ; data decoding , data encoding , and data transmission through the net and pc serial port ; further more , the gps receiver interface language has been analyzed to control differential reference station receiver 因此,差分gps技术( dgps )应运而生,并得到飞速发展,其市场前景看好。 dgps在许多定位应用中已经成为重要的定位系统,本文论述了差分gps的原理,阐明了伪距差分的基本原理与算法:在实践上针对实验室现有的比较先进的javad差分参考台进行了伪距差分修正量数据的提取、数据解码、数据编码、数据的网上传输。
At the same time , this paper presents packet recognition , transaction sequencing , sop , eop , reset , resume signal detection / generation , clock / data separation , nrzi data encoding / decoding and bit - stuffing , crc generation and checking ( token and data ) , packet id ( pid ) generation and checking / decoding , serial - parallel / parallel - serial conversion 对同步模式的识别、并行/串行转换、位填充/解除填充、 crc校验/产生、 pid校验/产生、地址识别和握手评估/产生做了具体的分析。