邮件系统是Linux网络应用的重要组成，一个完整的邮件系统包括三个部分：底层操作系统（Linux Operation），邮件传送代理（Mail Transport Agent，MTA），邮件分发代理（Mail Delivery Agent，MDA），邮件用户代理（Mail User Agent，MUA）。 Postfix是一个非常优秀的MTA，她素以高效、安全的特点而著称。Postfix是作者在UNIX上所见过的MTA中在反垃圾邮件（Anti- Spam或Anti-UCE）方面做得最好的一个，甚至有很多公司在Postfix代码的基础上进行二次开发而推出反垃圾邮件网关产品。MTA的反垃圾邮件功能，实际上就是在MTA处理过程中对会话进行过滤。这个过滤不但过滤了发往自身的垃圾邮件，而且还防止了自身被恶意利用发送垃圾邮件。Postfix 实现了目前所有主要的MTA过滤技术。postfix是Wietse Venema在IBM的GPL协议之下开发的MTA（邮件传输代理）软件。和Sendmail相比Postfix更快、更容易管理、更灵活、更安全。
上传时间： 2015-11-25
上传用户：dapangxie
The MAX504/MAX515 are low-power, voltage-output, 10-bit digital-to-analog converters (DACs) specified for single +5V power-supply operation.用于DA转换芯片选型
标签： digital-to-analog voltage-output converters MAX
上传时间： 2015-11-26
上传用户：541657925
Jitter is extremely important in systems using PLL-based clock drivers. The effects of jitter range from not having any effect on system operation to rendering the system completely non-functional. This application note provides the reader with a clear understanding of jitter in high-speed systems. It introduces the reader to various kinds of jitter in high-speed systems, their causes and their effects, and methods of reducing jitter. This application note will concentrate on jitter in PLL-based frequency synthesizers.
标签： extremely PLL-based important drivers
上传时间： 2014-11-25
上传用户：asddsd
This demonstration shows that reordering the rows and columns of a sparse matrix S can affect the time and storage required for a matrix operation such as factoring S into its Cholesky decomposition
标签： demonstration reordering the columns
上传时间： 2016-01-14
上传用户：奇奇奔奔
ST7529液晶驱动 The ST7529 is a driver & controller LSI for 32 gray scale graphic dot-matrix liquid crystal display systems. It generates 255 Segment and 160 Common driver circuits. This chip is connected directly to a microprocessor, accepts Serial Peripheral Interface (SPI), 8-bit/16-bit parallel or IIC display data and stores in an on-chip display data RAM. It performs display data RAM read/write operation with no external operating clock to minimize power consumption. In addition, because it contains power supply circuits necessary to drive liquid crystal, it is possible to make a display system with the fewest components.
标签： 7529 controller dot-matrix graphic
上传时间： 2013-12-02
上传用户：奇奇奔奔
编译的关于LL(1)词法分析的小程序，适合在VC下运行-compiled on LL (1) Morphological analysis of the small programs, for the VC teachers to run the operation no problem
上传时间： 2014-09-01
上传用户：sjyy1001
matlab经典算法的程序-特殊绘图，figure operation
上传时间： 2014-01-11
上传用户：yulg
Core JSP In recent years, a large amount of software development activity has migrated from the client to the server. The client-centric model, in which a client executes complex programs to visualize and manipulate data, is no longer considered appropriate for the majority of enterprise applications. The principal reason is deployment—it is a significant hassle to deploy client programs onto a large number of desktops, and to redeploy them whenever the application changes. Instead, applications are redesigned to use a web browser as a "terminal". The application itself resides on the server, formatting data for the user as web pages and processing the responses that the user fills into web forms.
标签： development activity migrated software
上传时间： 2014-01-13
上传用户：duoshen1989
Summary Many control applications require converting some analog input to a digital format. The ADCINC12 User Module is a general-purpose, 12-bit analog to digital converter (ADC) that does just that. This Application Note is meant to be a simple introduction into its operation. The steps required to define, place, and write software are presented. Examples are developed in both assembly and C.
标签： applications converting Summary control
上传时间： 2013-12-01
上传用户：WMC_geophy
The first task at hand is to set up the endpoints appropriately for this example. The following code switches the CPU clock speed to 48 MHz (since at power-on default it is 12 MHz), and sets up EP2 as a Bulk OUT endpoint, 4x buffered of size 512, and EP6 as a Bulk IN endpoint, also 4x buffered of size 512. This set-up utilizes the maximum allotted 4-KB FIFO space. It also sets up the FIFOs for manual mode, word-wide operation, and goes through a FIFO reset and arming sequence to ensure that they are ready for data operations
标签： appropriately The endpoints following
上传时间： 2013-12-02
上传用户：dianxin61
