实现图书管理

The (a) section of Figure 1 illustrates the Line Echo Canceller (LEC) residing in the access network where echoes occur. Other voice processing modules, such as Automatic Level Control (ALC) and Noise Reduction (NR), are shown merely for illustration purposes. On the terminal side, both acoustic and electrical echo can occur. If the voice terminal is a speaker telephone set with an open acoustical path from the speaker to the microphone, the effect of acoustical echo is combined with the effect of the network echo. Because there is only a miniscule delay between the electrical signal and its echo, the speaker/listener is exposed to an effect known as side tone. Typically, instead of mounting a LEC at the terminal, side tone circuitry is placed to control the amount of the returned energy. The (b) section of Figure 1 shows examples of echo canceller signals representing the following:

用matlab实现dds，并进行相关参数分析(Using matlab to achieve dds)

51单片机开发板LED流水灯 有C和汇编两版 直接可以打开(51 single LED lights have two editions of C and assembler)

51单片机UCOS系统移植，包括全部源码，以及自己写的部分代码，编译通过(The 51 single-chip UCOS system transplantation, to including the the the all source code, as well as to write their own of the part of the code, the compiler through)

说明：  基于stm32f4单片机和esp8266芯片的wifi透传程序(WiFi transmission program based on stm32f4 microcontroller and esp8266 chip)

MSP430F5438 flash操作实例程序(MSP430F5438 flash)

获取QQ密码 很简单的 可以试试哦(hook get QQ password so easy)

IEC104子站端源码，开普实验室测试通过

stm32 demo工程，适用于stm32F103平台

CSAPP书中的原地交换算法，用C语言写的。(in place swap code which is from CSAPP.)