检查串口是否联有modem

OnlineExam校园在线考试系统 v1.1，校园在线考试系统 + 后台系统管理，默认的后台数据管理员用户名和密码都是：admin，默认的验证密码都是：firekinger -OnlineExam Campus Online Examination System v1.1, the campus online examination system background systems management, the default background data administrator user name and password are : admin, the default password verification are : firekinger

根据c语言编程知识的完美演绎-c programming language based on the perfect interpretation of knowledge

波峰因数消减在无线通信系统的设计研究，包括wcdma,Td-scdma以及wimax等系统-peaks abatement factor in the wireless communications system design, including wcdma. Td- scdma systems and wimax

使用Visual C++编写的TCP与UDP协议的网络程序，能够使多机进行通信 -failed to translate

讲有线的仿真全过程 好东西啊 不错的 一定要看-Speakers wired the whole process of simulation ah good things must look pretty good

一款国产仿照飞利浦mfrc500的射频卡芯片1702中文操作手册-Philips made a replica of the RF card chips mfrc500 Chinese Operation Manual 1702

用TCP编写的chat_server和chat_client，一定要先运行chat_server，再运行chat_client，否则会出错。不必要一方一次说一句，一方可以连续说多句。用byte[],能显示汉字。-prepared by using TCP chat_server and chat_client, you must first run chat_server, re-running chat_client, otherwise they will be wrong. Unnecessary time that a party, that party can more consecutive sentence. With byte [], can show that the Chinese characters.

应用背景模拟AODV和AOMDV网格网络中的路由协议关键技术路由协议（AODV和AOMDV），网络模拟器2，移动网格，Tcl/Tk脚本编码，netwoork动画师（NAM），通过对上述代码的帮助我们可以分析 ；平均抖动等性能指标，平均端到端延迟，吞吐量。

Implements layered decoding using the sum-product-algorithm. Codes are input as a .txt file in A-list format.

本文主要阐述了DTMF的原理及如何在MATLAB上产生DTMF信号，主要涉及到电话拨号音合成的基本原理及识别的主要方法，利用 MATLAB 软件以及 FFT 算法实现对电话通信系统中拨号音的合成与识别。并进一步利用 MATLAB 中的图形用户界面 GUI 制作简单直观的模拟界面。 能够利用矩阵不同的基频合成 0 － 9 不同按键的拨号音，并能够对不同的拨号音加以正确的识别，实现由拨号音解析出电话号码的过程，完成对电话拨号音系统的简单的实验仿真。-This paper described the principle and how DTMF in MATLAB to generate DTMF signals, mainly related to the telephone dial tone of the basic principles of synthesis and identification of the main methods, the use of MATLAB software and the FFT algorithm on the telephone communication system dial tone Synthesis and Recognition . And further the use of MATLAB in the production of graphical user interface simple and intuitive GUI interface simulation. Able to take advantage of matrix synthesis of different fundamental frequency 0- 9 different keys of the dial tone and be able to different dial tone to be the correct identification, the dial tone from a telephone number to resolve the process of completion of the telephone dial tone system, a simple experiment simulation