查询词典 compact disc digital audio

In this paper, the concept of network security and security structures of OSI and Internet is introduced, and various threats confronting the computer network are also discussed. Several kinds of network information security technologies, including firewall technology, virtual private network, intrusion detection system, data encryption technology, identity authentication and security protocol etc. are also examined. The security of internal network is the biggest problem in the construction of each network. The solution to this problem lies in setting up a firewall. The theory of a firewall and the approach to its actualization is studied. Intrusion detection system, an important part of the computer network security system, has gained extensive attention. IDS monitors the computer and network traffic for intrusion and suspicious activities. It not only detects the intrusion from the extranet hacker, but also the intranet users. The emergence of virtual private network paves the way for realizing secure connection of LAN quickly and at a relatively low cost. The concept, function, key techniques, including the tunnel technology, and the ways to realize VPN are expounded in this paper. Also introduced is the data encrypt network technology, which is called the soul of computer network security, such as digital digest, digital signature, digital certificate, digital encrypt arithmetic and so on. At the same time, the principle and the process of implementing network security by digital certificate and digital signature, the basic principle and characters of security protocols, and finally, three of the security protocols, concerning the security problems in network, IPsec, SLL and SET are analyzed in detail Computer network system should be a system of dynamic defence, both dynamic and static, passive as well as active, and even offensive, combined with management and technology.

本文系统地介绍了网络安全的概念、OSI及Internet的安全体系结构，并讨论了计算机网络面临的各种安全威胁；内部网络的安全问题是每个建网单位面临的最大问题，可以认为防火墙技术是解决网络安全的一个主要手段，本文研究了防火墙的原理及其实现手段；作为一种主动的防御措施，入侵检测系统作为网络系统安全的重要组成部分，得到了广泛的重视，TDS对计算机和网络资源上的恶意使用行为进行识别和响应，不仅检测来自外部的入侵行为，也监督内部用户的未授权活动；虚拟专用网技术的出现，为实现网络间的连接提供了快速安全但又相对便宜的手段，本文较深入的探讨了实现VPN的隧道技术，并对VPN的概念、功能、实现途径、基本构成、关键技术及发展前景等问题进行了全面论述；数据加密技术是网络安全核心技术之一，本文从数据加密算法、数字摘要、数字签名及数字证书等几方面简要介绍了数据加密技术，并分析用数字证书和数字签名实现网络安全的原理和过程；对安全协议的基本原理、主要特点进行了较为深入的研究，并就网络的安全性问题剖析了三种安全协议：IPsec协议、SLL协议和SET协议。

In this dissertation, digital lock-in detection techniques under integer period sampling and non-integer period sampling are separately investigated (1) Under integer period sampling, digital signal sequence is acquired through sampling the measured signal, but digital reference sequence is acquired through mathematical operation, then digital lock-in detection can be realized by calculating crosscorrelation function of digital signal sequence and digital reference sequence Harmonic measure is also analyzed, and a method of measuring harmonic of a periodic signal under aliasing is put forward.

本文对使用采样ADC把模拟信号转换为数字信号并通过计算数字信号的相关函数来实现锁定检测的技术进行了研究，在此基础上设计了一个多功能的数字LIA并在一些科学实验中进行了应用。本文对整周期采样和非整周期采样时的数字锁定检测技术分别进行了研究。(1)在整周期采样时，对被测信号进行采样得到信号序列，而参考序列由数学运算得到，通过计算信号序列和参考序列的互相关函数就可实现锁定检测。

For preparing for the researches of text digital watermarking and advantaging other researchers" development when using the Chinese mathematical expression theory, this paper designs and realizes a development platform of Chinese mathematical expression. It has been proved by experiments that the platform"s function, execution speed and stability can satisfy the requirements of conversion and operation of enormous data.This research found out that the structure information of Chinese have plenty redundant information that can be used by the Chinese mathematical expression for the digital watermarking, the data embedded can possess better robustness. Based on this finding, this paper designs a kind of text digital watermarking method of embedding watermarking by using Chinese structure, and realizes the method by using the Chinese mathematical expression platform.Considering the watermarking embedding algorithms importance to the robustness of the text digital watermarking, this paper makes fully use of the advantage of the Chinese mathematical expression theory to design a kind of layered text method, which has being realized by using the Chinese mathematical expression platform. The layered text method can handle the text as a solid structure, and the embedding data havepreferable robustness.Finally, based on the researches of the text digital watermarking method and the text layered method, this paper integrates the method of making use of the Chinese structure embedding watermarking with the robust algorithm based on text layered, and realizes a brand-new text digital watermarking method. Proved by lots of experiments, this brand-new method has good robustness and better invisibility.

为了为研究工作做准备和方便其他使用汉字数学表达式理论体系的人进行开发，本文基于汉字数学表达式理论设计实现了一个汉字数学表达式平台，实现了Unicode汉字集中的汉字、汉字数学表达式、汉字的Unicode码之间的相互转化、依据汉字数学表达式提取汉字的结构信息、由汉字数学表达式在非中文平台上不依赖字库显示汉字的图像等功能，使用复合文档技术和流压缩技术进行数据的存储，使用对汉字数学表达式进行二叉树拆分来处理汉字数学表达式中包含的信息，使用自定义哈希函数来提高运行速度，实验证明，该平台功能、速度和稳定性完全能满足大量数据的转化和运算要求；通过研究表明汉字的结构信息中存在大量可使用汉字数学表达式理论加以利用的水印加载空间，加载在该空间的数据可以具有较好的鲁棒性，基于此，本文设计了一种利用汉字结构加载水印的文本数字水印方法，并使用汉字数学表达式平台将其实现；由于水印嵌入算法对于文本数字水印的鲁棒性至关重要，本文充分利用汉字数学表达式理论的优点，设计了一种文本分层的方法，并使用汉字数学表达式平台将其实现，使文本成为一个立体的空间，使嵌入在其中的数据具有更好的鲁棒性；最后在基于汉字数学表达式的文本数字水印嵌入方法的研究和基于汉字数学表达式的文本分层方法的研究的基础上，结合利用汉字结构嵌入水印的方法和基于文本分层的抗攻击文本水印嵌入算法实现了一种全新的文本数字水印方法，经实验证明，该方法有良好的鲁棒性和较好的隐蔽性。

The MCI device drivers are designed to support the playing and recording of waveform audio,the playing of MIDI(Musical Instrument Digital Interface)files,the playing of compact disk audio from a CD-ROM disk drive and the control of some video disk players.

MIC设备驱动器程序支持波形音频的播放和记录、MIDI文件的播放数字视频的播放，并且能对一些视盘播放器进行控制。

So, we combine CobraNet audio network technology, data transmitting technology, MCU technology and FPGA technology to develop interface and program of MCU, controlling PCB board, A/D converter PCB board, D/A converter PCB board, digital audio receive PCB board. At last, we construct a audio network and test it's performances.

本文紧密结合CobraNet 音频网络技术、数据传输技术、单片机技术和FPGA 技术，从事了单片机接口及控制程序设计、控制板设计、A/D 转换插卡设计、D/A 转换插卡设计、数字音频信号收发插卡设计，开发出了一系列音频网络设备，并组网测试。

Support 720p/1080i - Playback files in PC through wired Ethernet (10/100Mbps)- Playback the recorded contents in HDD; Playback the files stored in HDD - directly playback the files on external devices like USB drive, HDD, Card reader(through USB2.0 Host Port)- support multiple file format: MPEG 1 /2/4, DivX, Xvid, VCD/SVCD/DVD, MP3/WMA, Dolby digital, AC3, JPEG, Kodak picture CD - fast forward/reverse, repeat playback - view Pictures in various ways: Rotate, zoom, music slide show Transferring/storage function - with USB2.0 Target port and USB2.0 Host port - work as USB HDD when connected to USB port on PC for file store / backup / transfer (through USB2.0 Target port)- supports USB drive, HDD, Card reader data exchange (through USB2.0 Host port) Editing recorded A/V title without PC - HDD format - AB Erase, split title, merge title, add chapter mark - Copy, delete, Rename Terminals: Composite video in, composite video out, component video out, left/right audio in, left/right audio out, mini optical audio out, RJ45 net port, USB2.0 Host, USB 2.0 Target HDD Support IDE HDD, support FAT32 File Support FAT32 and NTFS Power: DC12V(1.5A) Power consumption: 1W, 6W.

支持720 p/1080i的影像-播放档案的电脑，通过有线以太网（ 1 0/100）-重放所记录的内容，在硬盘；重放档案储存在硬碟-直接播放该档案的外部设备，如U S B驱动器，硬盘，智能卡阅读器（通过u sb 2 0.0主机端口）-支持多种文件格式：的M PEG1 / 2 / 4 ，转换，音频，视像/格式/数码影碟， m p3/wma，杜比数字， a c3，的J PEG，柯达图片光盘-快速前进/扭转，重复播放-看照片以各种方式：旋转，缩放，音乐幻灯片播放转让/存储功能-与U S B2.0的目标端口和U S B2.0主机端口-工作作为U SB硬碟当连接到US B端口的电脑档案储存/备份/转让（通过USB2.0的目标端口）-支持U SB驱动器，硬盘，智能卡阅读器的数据交换（通过U SB2.0主机端口）编辑记录的音频/视频标题，没有电脑-硬盘格式-抗体抹掉的，分裂的所有权，合并名称，地址章马克-复制，删除，重命名终端：复合视频，复合视频，分量视频输出，左/右音频，左/右音效输出，迷你光学音效输出，接头R J45网络端口， U SB2.0主机， USB 2.0接口目标硬盘支持的IDE硬盘，支持FAT32文件的支持和FAT32和NTFS电源：： DC12V （ 1.5A和）耗电： 789， 6瓦特。

Shandong journey from the journey from Canton Electronics are electronics factory in Jinan in Shandong to set up offices, is responsible for "PCER journey from" Series Products in Shandong Province and other channels of distribution and after-sales service, Canton journey from an electronics factory (line forming the Department of cable) is a professional manufacturer of VGA lines / HDMI Digital Line / DVI digital line / USB Line / Parallel Port Print Line / 1394 digital line / KVM and three lines / MP3 Line / MP4 Line / power cord / AV Audio Video Cable / PS2 mouse keyboard line / network and other computer peripherals jumper cable; 2 are specialized in the production line RVV jacket / RVVP shield / 75-3 75-5 SYV Coaxial / 3 +4 3 +6 five core RGB coaxial lines and other projects large-screen security monitor cable; are specializing in the production of three VGA divider / VGA switch / VGA video devices extended / KVM Switch / KVM Extender / PC to TV (VGA signal transduction AV signal) converter / DVI digital signal splitter / DVI Switch / HDMI Splitter / HDMI switches and other products.

山东征途者电子是广州征途者电子厂在山东济南成立的办事处，主要负责&PCER征途者&系列产品在山东省的渠道分销及售后服务等，广州征途者电子厂一部是专业生产VGA线/HDMI数字线/DVI数字线/USB线/并口打印线/1394数码线/KVM三并线/MP3线/MP4线/电源线/AV音视频线/PS2鼠标键盘线/网络跳线等电脑周边连接线；二部是专业生产RVV护套线/RVVP屏蔽线/75-3 75-5 SYV同轴线/3+4 3+6 五芯同轴RGB大屏幕线等工程安防监控线缆；三部是专业生产VGA分频器/VGA切换器/VGA影音延长器/KVM切换器/KVM延长器/PC转TV转换器/DVI数字信号分配器/DVI切换器/HDMI分配器/HDMI切换器等产品。

Then the digital audio signal is set into segments and DWT is performed. Finally the modulated signal is embedded in the coefficients with relatively large absolute value on middle frequency range detail signal adaptively. The original digital audio signal is necessary when detecting the watermark.

在应用扩频技术的算法中，首先将视觉上可辨的二值水印图像降维为一维序列，再将一维水印序列伪随机排序并与m序列作扩频调制，最后对数字音频信号进行分段离散小波变换，把经过调制的水印信息自适应地嵌入到原音频信号小波分解中等尺度绝对值较大的分量上。

The research of the digital audio-frequency technique combining the embedded system has the extensive foreground, The digital audio-frequency equipments based on the embedded system have be attended all over the world because of its high ratio of sexual valence , the quickly development speed ,and etc.

结合嵌入式系统的数字音频技术研究有着广阔的前景，基于嵌入式的数字音频设备以其高性价比、日新月异的发展速度等优点受到世界各国的广泛关注，本文结合市场发展需要，提出了一个比较优化的解决方案，并从理论和实践两方面对该方案进行了分析和设计。

This text works at the applied design and research of the digital audio-frequency technique in the embedded operate systems, deeply discusses the design thought and the achievement method of the whole system in the software and hardware, put forward the transplantation project of transplanting the μ c/ OS-Ⅱembedded operate system into the ARM microprocessor, and the achievement method of the digital audio-frequency files of decoding in the software.

本文致力于数字音频技术在嵌入式操作系统中的应用设计和研究，深入讨论了整个系统的软硬件设计思想与实现方法，提出了μc/OS-Ⅱ嵌入式操作系统在ARM微处理器上的移值方案，以及数字音频格式文件在软件解码上的实现方法。

Metrorrhagia is also gynaecological problems of common diseases.

崩漏是妇科常见病也是疑难症。

WordFTP gives you the convenience and timesaving you need.

wordftp让您的方便和省时您所需要的。