查询词典 digital camera

along with the development of digital technology,digital filters are widely used in many fields,this paper introduces how to design a iir digital notch filters in matlab environment.the design of digital notch filters can be achieved through three steps:firstly,the design of analog lowpass filter; secondly,it is analog lowpass to analog band stop filter conversion;at last,using the bilinear transformation make the analog notch filters change into digital notch filters.the paper also introduces how to design the transfer function of the digital notch filters using all the zeros and farthest points at the same time,it also introduces the program of the digital notch filters under butterworth analog lowpass prototype.

摘 要：随着数字技术的发展，数字滤波器在许多领域得到广泛的应用。研究一种在matlab语言环境下设计iir数字陷波滤波器的方法，在数字陷波滤波器设计过程中，先进行模拟低通滤波器的设计，然后进行模拟低通/模拟带阻滤波器转换，最后采用双线性变化法将模拟陷波滤波器转化成数字陷波滤波器。提出一种用所有零点和极点来表达数字陷波器传递函数的方法，同时给出以巴特沃斯模拟低通为原型设计数字陷波滤波器的程序。关键词：无限冲激响应；巴特沃斯滤波器；数字陷波滤波器；matlab；双线性变换

3609Today we have sale No.6\No.5 cameras in China, That's not high enough, we have to move farer, on the total global basis, we are No.4, and in the United States, we No.2, I believe with the right effort in China, we can move up to a much higher level, 2 or 3 for sure, and now it is the time because the digital camera market is just getting started in China, actually it is very small in terms of penetration, I am glad everybody here uses the digital camera, but if you don't afterwards I will sell you a digital camera

目前我们相机在中国市场的销售是占第六第五这个位置，这个份额不够高。所以我们必须向前发展。从全球范围来看，我们的销售占第四位，在美国占第二位，我相信，通过在中国的不懈努力，我们可以更上一层楼，争取到第二或第三的位置。我想现在正当好时机，因为数码相机在中国刚刚起步，无论从规模或是渗透力来讲都比较小，看到你们当中的每个人都在用数码相机，我感到很高兴，如果你没有的话，那么过一会我可以卖给你一个。

The main routes of this graduation thesis is to compile uniformity gradient or MTF software 、match for the quality of digital cameral image the last of digital images and give a comprehensive evaluation for the digital image in discussion the basic principles of digital mapping cameras and digital camera-image quality evaluation.

本次毕业文的主要研究内容是在讨论数码航摄仪的基本原理和数码航摄仪影像质量评价的基本原理上，编写均匀梯度和MTF软件对数码航摄仪影像质量进行匹配，最后对数码航摄仪影像进行综合评价。

The main content of this thesis includes six parts. First of all, it is a comprehensive systematic introduction about RSA algorithm including the present application situation and principle of RSA algorithm----producing big prime numbers and secret keys, the encryption arithmetic for information and the decryption for secret information, which establish the theory foundation for achieving concrete; secondly, it introduces some basic conception of RSA digital signature and theory of digital signature realizing process; thirdly, it introduces the basic principle of MD5 algorithm; fourthly, it states design and realization of RSA digital signature in detail. The main modules includes producing RSA secret keys, implementation of RSA encryption algorithm and decryption algorithm, producing message digest and realizing digital signature and verification by RSA; the fifth, it carries on testing entirely, analyzing and improving for this system;The sixth, it analyses the security of RSA digital signature and points out the development direction of RSA digital signature.

本文主要研究的内容包括：第一，对RSA算法进行了全面系统的介绍，包括RSA算法的应用现状和原理—大素数的产生、密钥对的产生、对明文的加密运算和密文的解密运算，为具体实现打下了理论基础；第二，介绍了RSA数字签名的一些基本概念和数字签名的理论实现过程；第三，对MD5算法基本原理的介绍；第四，详述了RSA数字签名的设计与实现，主要实现的模块包括RSA密钥的产生，RSA加密算法和解密算法的实现，消息摘要MD的生成以及利用RSA算法实现数字签名和签名的验证；第五，对该系统进行了整体的测试和分析改进；第六，分析了RSA数字签名的安全性，指出了RSA数字签名的发展方向。

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。

Receives from the dealer news, recently the Matushita digital camera carried on promotion, now the Matushita fs3 price continues to maintain at 1288 about prices, bestows 4g the sd card and the original installation camera package, Matushita fs3 is immediately in the present fs series a least significant end type, has receives the high praise mega the o.i.s optics against to shake the function, under the near future wants to buy thousand Yuan rank digital camera's friend to be possible to pay attention.

10月23日太平洋电脑网广州讯】收到来自经销商消息，近日松下数码相机进行促销活动，现在松下fs3的价格继续维持在1288左右的价位，随即赠送4g sd卡和原装相机包，松下fs3是现时fs系列中最低端的一款机型，具有备受好评的mega o.i.s光学防抖功能，近期想购入千元级别数码相机的朋友可以留意下。

A digital single- lens reflex camera is a digital camera that uses a mechanical mirror system and pentaprism to direct light from the lens to an optical viewfinder on the back of the camera.

所谓数字单镜头反光相机是指使用机械反光镜系统和五棱镜把光线从镜头引导至相机背后的光学取影器中的一种数码相机。

The present invention provided a digital camera and a digital single-lens reflex camera which do not give damage to an imager in deciding framing even in the case of a single-lens reflex camera capable of through-image output.

提供即使是能够实时取景输出的单镜头反光式照相机，也不会在决定成帧时对成像器带来损害的数字照相机以及数字单镜头反光式照相机。

The system can be widely used in belt weighing and batching process control,etc.

介绍了基于智能模糊控制的嵌入式配料系统的设计方法，对模糊PID控制过程和系统调零作了重点的讨论，同时给出了PID控制的程序流程图和系统定长调零子程序。

"I dunno," she answered,"but if you show me aroun', I'll recognize it from the lighthouse just outside the porthole."

"我不知道，"她回答说，"如果你能带我转转，我能认出来的，因为灯塔就在舷窗外。"