阐述了轨道交通列车定位技术。介绍了在轨道交通系统中列车定位技术的功能，国内外轨道交通中主要采用的列车定位方法，重点论述了几种主要定位技术，并从定位精度、闭塞制式、维护投资成本、抗干扰等方面进行分析比较。提出目前轨道交通定位技术应综合运用，取长补短，多种方法相互融合，才能满足轨道交通中对安全可靠性的要求。 Abstract: Rail train positioning technology is described. The paper introduces the funetions of the train positioning technology in the rail transit system， the main methods of train positioning do mestic and international rail， and focuses on several key methods， analyzes and compares from the positioning accuracy， block system, maintenance and investment cost， interference and so on， suggested that the current rail positioning technology should be integrated use of positioning method of meriging， learn from each other， to meet the reliability requirements of rail safety.
上传时间： 2013-11-25
上传用户：franktu
提出了一种以ARM微处理器为控制核心的远程无线视频监控终端的设计方案，其监控终端的硬件设计包括视频采集处理、中央管理控制、无线传输3个模块。并给出了监控终端的软件开发平台和开发模式的系统启动代码、嵌入式Linux系统移植以及驱动程序和应用程序。测试结果表明，该监控终端设计方案合理、有效，基本满足监控需求。 Abstract: A remote wireless video monitoring terminal design， which uses ARM microprocessor as its core control， is proposed in this paper.The hardware design of monitoring terminal system is composed of the video acquisition and processing module， the central management and control module， wireless transmission module.Meanwhile the monitoring terminal-s software development platform and development patterns are designed. Also the design of the system-s start codes， embedded Linux system-s transplantation process， driver and the corresponding applications are given. The results showed that the monitoring terminal design is reasonable， effective， basically meet monitoring requirements.
上传时间： 2013-11-13
上传用户：wanqunsheng
Introduction to Xilinx Packaging Electronic packages are interconnectable housings for semiconductor devices. The major functions of the electronic packages are to provide electrical interconnections between the IC and the board and to efficiently remove heat generated by the device. Feature sizes are constantly shrinking, resulting in increased number of transistors being packed into the device. Today's submicron technology is also enabling large-scale functional integration and system-on-a-chip solutions. In order to keep pace with these new advancements in silicon technologies, semiconductor packages have also evolved to provide improved device functionality and performance. Feature size at the device level is driving package feature sizes down to the design rules of the early transistors. To meet these demands, electronic packages must be flexible to address high pin counts, reduced pitch and form factor requirements. At the same time,packages must be reliable and cost effective.
上传时间： 2013-11-21
上传用户：不懂夜的黑
The Virtex-4 features, such as the programmable IDELAY and built-in FIFO support, simplifythe bridging of a high-speed, PCI-X core to large amounts of DDR-SDRAM memory. Onechallenge is meeting the PCI-X target initial latency specification. PCI-X Protocol Addendum tothe PCI Local Bus Specification Revision 2.0a ([Ref 6]) dictates that when a target signals adata transfer, "the target must do so within 16 clocks of the assertion of FRAME#." PCItermination transactions, such as Split Response/Complete, are commonly used to meet thelatency specifications. This method adds complexity to the design, as well as additional systemlatency. Another solution is to increase the ratio of the memory frequency to the PCI-X busfrequency. However, this solution increases the required power and clock resource usage.
上传时间： 2013-11-24
上传用户：18707733937
The revolution of automation on factory floors is a key driver for the seemingly insatiable demand for higher productivity， lower total cost of ownership，and high safety. As a result， industrial applications drive an insatiable demand of higher data bandwidth and higher system-level performance. This white paper describes the trends and challenges seen by designers and how FPGAs enable solutions to meet their stringent design goals.
上传时间： 2013-11-08
上传用户：yan2267246
The high defi nition multimedia interface (HDMI) is fastbecoming the de facto standard for passing digitalaudio and video data in home entertainment systems.This standard includes an I2C type bus called a displaydata channel (DDC) that is used to pass extended digitalinterface data (EDID) from the sinkdevice (such as adigital TV) to the source device (such as a digital A/Vreceiver). EDID includes vital information on the digitaldata formats that the sink device can accept. The HDMIspecifi cation requires that devices have less than 50pFof input capacitance on their DDC bus lines, which canbe very diffi cult to meet. The LTC®4300A’s capacitancebuffering feature allows devices to pass the HDMI DDCinput capacitance compliance test with ease.
上传时间： 2013-11-21
上传用户：tian126vip
从空格(ASCII码32)到~(ASCII码126)。表内的第一行与表头相同，下面的每一行都与上一行的内容相同，只是字符相左移动了一个位置。这样，下一行的最后一个字符与上一行的第一个字符相同。 为了进行文本编码，可以任意选择一个字符串，称之为编码字符串，也就是常说的密钥。为解释编码方法，我们假设密钥是Walrus，待编码的文本（即常说的明文）是： meet me in St. Louis 我们在待编码的文本之上重复书写上述密钥，使得其长度与待编码文本相同： WalrusWalrusWalrusWa meet me in St. Louis 从上述两行文本中按列对应方式依次提取一个字符，可得到多个字符对：WM、ae、le等，这些字符对可用作上表的索引。这样，依次以这些字符对作为索引可从上表查到一系列字符，这些字符就构成了文本编码，即常说的密文。例如，第W行第M列队应得字符是%，因此编码的第一个字符就是%；第a行第e列对应的字符是G；第l行第e列对应的是R。依次进行上述查找操作，可以得到完整的密文 %Grgua=aVauGLol?eiAU 进行相反的操作就可对该文本解码。 编写编码/解码程序，可以对文本文件或键盘输入的字符串进行编码/解码，在选择编码解码后，需要提示用户输入密钥。
上传时间： 2014-01-16
上传用户：Ants
The Personal Software Process (PSP) shows engineers how to: 1)manage the quality of their projects 2)make commitments they can meet 3)improve estimating and planning 4)reduce defects in their products
标签： engineers Personal Software projects
上传时间： 2014-12-05
上传用户：Avoid98
PCI-to-PCI Bridge Architecture Specification Revision 1.1 This specification establishes the requirements that a PCI-to-PCI bridge must meet to be compliant to this specification and the PCI Local Bus Specification. In addition, the requirements for optional extensions are specified. This specification does not describe the implementation details of any particular requirement or optional feature of a PCI-to-PCI bridge, nor is it a goal of this specification to describe any particular PCI-to-PCI bridge implementation. However, some recommendations are provided for some implementation-specific features that can be provided by a PCI-to-PCI bridge.
标签： Specification specification Architecture establishes
上传时间： 2014-01-14
上传用户：caiiicc
Introduction to the MSN Messenger Activity SDK --- --- --- --- --- --- --- --- --- --- --- --- --- -- The MSN® Messenger Activity software development kit (SDK) contains technical information about how to develop and test single-user and multiuser applications by using the Activity object model. The SDK also provides detailed information about the MSN development and testing requirements that your Activity must meet, and how to increase the usage of your MSN Messenger Activity application.
标签： Introduction Messenger Activity the
上传时间： 2015-09-06
上传用户：ruan2570406
