异步计算机

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

ABSTRACT A major development in high-speed networking is the emergence of Broadband Integrated Service Digital Networks and Asynchronous Transfer Mode .

高速计算机网络互联技术的主要进展是宽带综合业务数字网和异步转移模式的出现。

Large systems and computer networks typically use more sophisticated methods of transmission, such as synchronous or bisynchronous, because of the large overhead penalty of 20% in asynchronous transmission.

大型系统和计算机网络通常使用更为复杂的传输方法，例如同步或双同步。异步传输中存在超过20%的传输损失。

Petri net is a kind of computer system model to describe asynchronous and intercurrent system.

Petri网是适合于描述异步的、并发系统的计算机系统模型。

Firstly, oscilloscope control system based on GPIB technique is presented with friendly operation environment to the HIFU system, and it uses multithreading technique in programming to realize real-time recording and display of the signal; Secondly, temperature collection and data recording system is designed, which also could get real-time recording and display of the 16 channel temperature signal, and it's believed to be of great use for further experiments of the HIFU system; Thirdly, multiple ultrasonic phased array's phase shifter is designed,which could provide 8-bit phase control in a range of frequency where the centrical frequency is 1MHZ. Fourthly, the module of serial communication is realized to insure the communication between devices and computer, including both synchronous and asynchronous communication, which enables the system to transfer data reliably and stably; Finally, the module of digital quantity control is accomplished, which provide for upper application the consistent solution to the control of exterior devices via digital interface. It can get or set the devices state using interrupt mode to receive input signal or send output signal.

主要有以下几个方面：设计了基于GPIB的示波器控制系统，给课题的研究工作提供了一个良好的环境，它采用了多线程编程的方法，能够较好的实时显示当前波形并记录数据；设计了温度采集和数据记录系统，能够对16路温度信号进行并行同步的实时采集，用于HIFU剂量学研究中温度场检测和医疗评价；设计了相控阵相位延时电路并且通过调试，满足了课题的相位控制的要求，在中心频率为1MHZ左右的频率范围内都能够达到8-bit相位控制；实现了串口通讯模块，为各项设备与计算机之间的通讯提供保证，它提供同步和异步的通讯能力，使系统能够可靠稳定的传输数据；建立了数字量控制模块，为上层应用程序提供一致的方法使用数字接口控制外部仪器，它使用中断的方式来接收输入或输出设定的开关量信号，从而得到或设定各种仪器的状态。

Petri net is a kind of model fit for describing asynchronous and intercurrent phenomenon.

Petri网是一种适合于描述异步并发现象的计算机系统模型。

The attributes of asynchronous, synchronous, and isochronous data transmission come from the fields of computer communication and switching.

在计算机通信和交互领域中有三种数据传输方式，它们是异步传输和等时传输。

A method of inputting data into a computer system without a regular or predictable time relationship.

异步输入不按固定的时间关系向计算机系统输入数据的一种数据输入方式。

It introduces programming ideas and application analysis of single phase capacitor functioning asynchronous motor design, containing: computer auxiliary design and analysis, digital process of curves and charts, total program flow chart, subprogram performance and key technology realization.

本文来源是宁波君禾泵业有限公司的水泵电动机设计软件开发项目，介绍基于VC++的单相电容运转异步电动机设计程序编制思想和应用研究，包括：计算机辅助设计分析、曲线和图表的数学处理、流程图、子程序功能和关键技术实现。

By far the most popular serial interface between a computer and its CRT terminal is the asynchronous serial interface, and between a circuit switch and its telephone terminal, the synchronous one.

在计算机与其显示终端之间最为常见的串行接口是异步串行接口，而在电路交换机与其电话终端之间最为常见的串行接口是同步串行接口。

And Pharaoh spoke to Joseph, saying, Your father and your brothers have come to you.

47：5 法老对约瑟说，你父亲和你弟兄们到你这里来了。

Additionally, the approximate flattening of surface strip using lines linking midpoints on perpendicular lines between geodesic curves and the unconditional extreme value method are discussed.

提出了用测地线方程、曲面上两点间短程线来计算膜结构曲面测地线的方法，同时，采用测地线间垂线的中点连线和用无约束极值法进行空间条状曲面近似展开的分析。