基于智能传感器和VB6.0/ACCESS的温湿度测量系统

运用VB6.0的串行通信控件,实现计算机与多个智能温湿度传感器的串行通信;在VB6.0环境下,调用ACCESS数据库进行数据保存。该方法实现了分散智能传感器的集中控制、数据的自动采集与自动保存。     

Traffic Adaptive PRMA Techniques for ATM Wireless Networks

High-speed asynchronous transfer mode (ATM)wireless networks are assuming a growing interest in thepersonal communication area. This paper proposes anaccess technique for such networks, which is being implemented in the MEDIAN project belonging tothe European Community (EC) Advanced CommunicationsTechnologies and Services (ACTS) program. The proposedaccess technique aims at providing a simple, efficient, and transparent transport for ATM cells from abase station (BS) interfaced with the ATM network, toATM portable stations (PSs) and vice versa. Atime-division duplex (TDD) scheme is adopted in whichuplink and downlink frame durations can be variedframe-by-frame, in order to fit the presentuplink/downlink traffic mix. In the uplink, anappropriate packet reservation multiple access(PRMA)-based technique is considered.     

Algorithms Transformation Techniques for Low-Power Wireless VLSI Systems Design

This paper presents an overview of algorithmtransformation techniques and discusses their role inthe development of hardware-efficient and low-power VLSIalgorithms and architectures for communication systems. Algorithm transformation techniquessuch as retiming, look-ahead and relaxed pipelining,parallel processing, folding, unfolding, and strengthreduction are described. These techniques are applied statically (i.e., during the system designphase) and hence are referred to as static algorithmtransformations (SATs). SAT techniques alter thestructural and functional properties of a givenalgorithm so as to be able to jointly optimizeperformance measures in the algorithmic (signal-to-noiseratio [SNR] and bit error rate [BER]) and VLSI (powerdissipation, area and throughput) domains. Next, a new class of algorithm transformations referred toas dynamic algorithm transformations (DAT) is presented.These transformations exploit the nonstationarity in theinput signal environment to determine and assign minimum computational requirements foran algorithm in real time. Both SAT and DAT techniquesare poised to play a critical role in the development oflow-power wireless VLSI systems given the trend toward increasing digital signal processing inthese systems.     

Wireless ATM: Performance Evaluation of a DSA++ MAC Protocol with Fast Collision Resolution by a Probing Algorithm

In general, the users of wireless ATM terminalsrequest the same functionality and quality of service asusers of wired terminals. These user requirements can betransformed into the demand for building an ATM multiplexer around the air interfacewhich is characterized by a radio channel inside. Themain difference between this virtual ATM multiplexeraround the air interface and a fixed ATM multiplexer is the distribution of the multiplexingfunction between wireless terminals and the basestation. For the uplink this requires a frequentnotification of the ATM cell scheduler in the basestation about the status of the incoming buffers inside thewireless terminals. This paper focuses on differentmethods for transmitting capacity request messages (alsodesignated as reservation request) over theuplink.     

Buffered Type-II Hybrid ARQ Protocol for DS-SSMA Packet Radio Systems

The performance and stability of a slotteddirect-sequence spread-spectrum multiple-access (DSSSMA)packet radio network employing the type-II hybridautomatic-repeat-request (ARQ) protocol withfinite-length transmitter buffers are considered. Theequilibrium point analysis (EPA) technique is employedto analyze the system stability and to approximatelycompute the system throughput, delay, and packetrejection probability. It is found that the systemexhibits bistable behavior in some situations. Issues ofsystem design, such as the required length of thetransmitter buffers and the desirable region ofoperation based on a predetermined performancerequirement for packet rejection, are alsoinvestigated.     

对VF用户如何学好ACCESS的探讨

从Visual Foxpro用户的角度对比分析ACCESS与Visual Foxpro的差异,并进一步阐述ACCESS中的数据库对象及编程方法。     

基于modbus协议的空间分布式温湿度测控系统设计

Modbus是工业控制器网络协议中的一种，可广泛应用于工业网络通信领域。文中介绍了基于该协议的空间分布式温湿度参数监测控制系统的设计方法，该系统利用485网络收集数据．并结合VB方便的图形界面和access强大的数据库功能来完成温湿度的测量与控制。     

Performance Evaluation of a Logical Link Control Protocol for an ATM Air Interface

The paper deals with error control proceduresbased on repetitions necessary for an ATM air interface,which enables a full integration of wireless (W) ATMterminals into a fixed ATM network. The architecture and functionality of an additional LLC layer atthe air interface are explained. A set of ARQ protocolsfor the different ATM service classes is investigated.The protocol for VBR services is able to control the number of retransmissions depending on therequirements on maximum delay and residual cell lossratio. It also takes into account instantaneousconditions such as channel load from other sources.Furthermore, the protocol is able to discard ATM cells toavoid and resolve congestion. The performance of theprotocol has been evaluated by simulations.     

快速加热的晶粒度预测与信息管理系统

利用通用的VB和ACCESS软件，成功地开发了GSPMIS计算机程序，用于科学管理快速加热过程中大量的日常生产数据，并在此基础上分析相关数据，进行晶粒度预测，实现了数据库的初步智能化。说明了系统的设计思想，阐述了各组成部分的功能和相关算法，也简略介绍了数据库编程的步骤，并试图说明怎样将一定的专业知识和计算机技术结合来编写专业软件。     

基于VB和ACCESS的机械产品FTA及FMECA一体化研究

分析了传统FTA及FMECA在机械产品应用上的不足,提出了FTA及FMECA一体化的思想,并基于VB和ACCESS建立了FTMECA系统,不仅能完成传统FTA及FMECA的任务,还具备更多的实用分析功能。