通信系统

NGN international community is the first set of today's Internet communication platform e-mail, instant messaging, text messaging (SMS, Network video phone, IPTV, commercial platform (network system, the Bank of Credit and, C2C, B2C, B2B) and multi - dividend level entrepreneurship platform advertising network into the community, dedicated to entertainment, life, business connections, such as integrated services, to promote interaction between people of good faith, and its goal is to build a global user no national boundaries, there is no difference, not distinction as to race, gender, age, international platform.

NGN国际社区是当今互联网上首家集通信平台电子邮件、即时通信、短信(SMS、网络可视电话、IPTV、商务平台（人脉系统、信贷银行、C2C、 B2C、B2B）和多层次广告分红创业平台为一体的网络社区，致力于娱乐、生活、商务人脉等综合性服务，提倡人与人之间的真诚互动，其目标是为全球用户搭建一个没有国界、没有时差、不分种族、性别、年龄的国际平台。

Unlike the actor concept originally proposed by Agha, actors in Ptolemy II do not necessarily associate with their own thread of control and stress concurrency and communicating abstraction.

目前推出的Ptolemy II[3]是Ptolemy项目组研制的第二代产品，它提倡面向角色的设计方法学，角色作为系统的基本组件，不同于Agha原来提出的角色概念，它在角色中不封装任何控制线程，而强调并行和通信抽象，认为时间是首要概念，并通过端口和参数定义的接口通信，而角色间的交互模式由计算模型控制。

This paper analysis the performance of both slotted-ALOHA and ALOHA protocol.

然后通过对常见的时分多址无线通信协议的分析，给出了该系统通信协议的设计方案。

Short-range wireless communication technology has attract many people"s interests now. Bluetooth is an international standard for it, but it now has a lot of problems. This paper first analyzed Bluetooth"s basic theory,architechure,solution. To meet this great market this paper put forward a low-cost and easy solution.

短距离无线通信是当前的一项热点技术，已经制订的国际标准是蓝牙，本文首先分析了蓝牙技术的基本原理、系统结构和实现方案，根据蓝牙目前存在的一些问题，本文提出了一种简单实用的短距离无线通信解决方案。

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。

Chapter 2 explain the base of mathematics, the mode of system, the principle of communication and the principle of PN code, and go along analysis of mathematics.

第二章是扩展频谱通信的数学基础、系统模型、通信原理和伪随机编码原理，并进行了数学分析。

Because it is more superior than that of the binary scale FSK and OOK that the binary scale moves the looks key and accuses of the system in resisting noise performance and channel communication frequency band utilization ratio etc., widely used in digital communication.

二进制移相键控方式是受键控的载波相位按基带脉冲而改变的一种数字调制方式。由于二进制移相键控系统在抗噪声性能及信道通信频带利用率等方面比二进制FSK及OOK的优越，因而被广泛应用于数字通信中。

Because it is more superior than that of thebinary scale FSK and OOK that the binary scale moves the looks keyand accuses of the system in resisting noise performance andchannel communication frequency band utilization ratio etc., widelyused in digital communication.

二进制移相键控方式是受键控的载波相位按基带脉冲而改变的一种数字调制方式。由于二进制移相键控系统在抗噪声性能及信道通信频带利用率等方面比二进制FSK及OOK的优越，因而被广泛应用于数字通信中。

This paper precisely conducts the special topic research in view of some important technologies of the digitized control module.(1) AC motor control circuit of PAN/TILT is designed ,which speed is controlled by AT89C51 MCU. DC motor control circuit of LENS is designed too.(2) The hardware and software of automatic temperature control is designed, which used in camera protect box without A/D IC. A kind of single wire communication IC is used in the circuit. So, the program is given.(3) A method of video switch without picture shock is discussed in this paper, and 16x8 video switch circuit is designed. AT89C51 can carry out time sequence logical control with the sync signals by request..(4) The module of real-time clock is designed, in which, LCM is used, a kind of three-wire communication IC is used too.

1给出了一种由89C51单片机控制的简单易行的交流云台转动变速控制电路，实现了云台及其电动三可变镜头的控制；(2)给出了无需外加A/D、单线通信的防护罩自动温度控制电路，完成了单片机温度控制软件的设计；(3)提出了"无抖动"视频切换的设计思想，给出了16×8的视频切换电路，利用单片机在视频信号的场消隐期控制切换，从而实现了"无抖动"切换；(4)给出了一种三线接口通信的液晶显示实时时钟电路，完成了程序设计；(5)提出了在视频监控系统数字控制模块中，用CAN总线取代传统的RS-485总线，实现PELCO-P协议传输的方案。

Custom communications system, through an agreement with the carrier detect achieve the two-way synchronous communication.

系统通过自定义通信协议，实现带有载波侦测的双向同步通信。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。