数字数据

The method includes steps: digital watermark technique is adopted to hide information of key data in not key data codes of compressed image; under protection of digital watermark, using protective backup for key data detects whether normal transmitted key data is correct or not so as to detect error code; carrying out cyclic mutual backup by using macro blocks in same positions in front and back macro block set; embedding coded motion vector in form of digital watermark to DCT transformation coefficient, and ensuring that video data are not influenced as best as one can; when error code occurs, if key data backup is correct, then the backup replaces former key data; otherwise, using mean value of key data in adjacent macro blocks within same frame to replace former key data approximately.

本发明中，采用数字水印技术在压缩图像的非关键数据编码中隐藏关键数据信息；通过数字水印保护下的关键数据保护备份来检测正常传输的关键数据是否正确，由此来检测传输误码；用前后宏块组中相同位置的宏块进行循环相互备份；对运动向量进行编码，然后以数字水印的形式嵌入到相对不重要的DCT变换系数中，同时保证视频数据尽量不受影响；在误码发生时，如果关键数据备份正确，则直接替代原关键数据，否则用同一帧内相邻宏块的关键数据的平均值近似替代原关键数据。

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。

Based on the summarization of metadata, DL and DLIO, this paper illustrates the essentialness of metadata"s application in DLIO, the organization structure of DL"s information resources, metadata standard design and metadata creating in DL. After this, it introduces and analyzes the application of DC, MARC and Chinese metadata standard in DLIO and gives an applied case.

本论文以元数据概述和数字图书馆及其信息组织概述作铺垫，对元数据应用于数字图书馆信息组织的必要性、数字图书馆信息资源的组织结构、数字图书馆元数据标准的选择与设计及元数据的编制进行了详细阐述，之后，又对数字图书馆信息组织中广泛使用的DC元数据、MARC以及具有代表性的国内专门数字对象中文元数据标准进行了介绍与分析，并辅之以上海数字图书馆元数据方案的实例。

After analyzing characteristics of urban spatial data, this paper partly implements the integration of spatial data of multi sources and organization and management of sea-large spatial data. Finally, the spatial data managing system makes a uniform management, maintenance and updating on such data as digital linear graphic, digital elevation map, digital orthoimage, digital raster data, reference points and metadata.

本文针对城市空间数据特征分析，部分实现了多源空间数据的集成和海量空间数据的组织与管理，实现了多库一体化分布式城市空间数据管理系统，将数字矢量线划数据、数字正射影像数据、数字高程模型数据、数字栅格数据、控制点数据以及元数据的进行统一的管理、维护和更新。

the digitized mapping technique is to combine the field data collection system with the computer assisted mapping system in surveys by computer technology.it aims to realize the information collected and processed digitally and automaticaity.the digitized mapping technique can cut short the working time,lighten the labor intensity and enhance the precision of the productions.the system consists of three parts,such as data input,data processing and data output.the survey-record digitized mapping technique is widely used in the digitized mapping working pattern.for its superiority over traditional plane-table mapping in accuracy and efficiency,the large scale digital mapping is becoming more and more popular.compared with traditional analogue mapping,digital mapping has more quality control pivotai points,and its contents and methods are more complex.with the appearance of new technology gps ,the coordinate of different levels controlling points may be surveyed in high precision and it has been applied widely in topographic survey.the operation process of gps electronic tachometer is introduced and its application in topographic survey is br

计算机应用论文，计算机论文， rtk ，全站仪，数字测图，地形测量， gps论文摘要：数字测图是在测量工作中利用电子计算机技术将野外数据采集系统与内业机助制图系统相结合，其目标是实现信息采集处理的数字化、自动化、信息化。数字测图可以缩短作业时间，减轻劳动强度，提高成果精度。数字测图系统主要由数据输入、数据处理和数据输出3部分组成，数字测图作业模式中测记式数字测图应用最为广泛。大比例尺数字测图正以其测图精度高，成图速度快等优势逐步的取代传统的，以平板仪为主的模拟测图。与传统的模拟测图相比，数字测图的质量控制关键点更多、内容与方法更为复杂。gps 新技术的出现，可以高精度并快速地测定各级控制点的坐标，在地形测量中已得到广泛地应用。本文介绍了gps 配合全站仪的作业流程，简要阐明了其在地形测量中的应用。在利用实测数据成图的过程中，解决一些常见的问题，并给出解决的办法及依据，同时给出一些有益的结论，以适应实际使用的需要。

The requirements for this are as follows: no need to analyze the primitive data;the information net system and subsidiary facilities for analyzing must be safe and reliable;signature needed after the data before analyzing;the concrete and detailed account of obtaining process should not only be given,but be classified and stored.

电子取证的要求是：不要对原始数据进行直接分析；分析数据的信息网络系统及其辅助的设备必须安全、可靠；分析前对数据进行数字签名；对数据获取过程进行详细、具体的描述，并归档、保存。电子取证的方法包括：数字鉴定法；数据检查法；数据对比法；数据保护法；数据分析法；证据抽取法。

The digital map input and maintenance subsystem performs format conversion,editing and updating of spatial data;the rail-track video playing subsystem uses video recording as reference data,then plays,inquires and traces the corresponding frames in synchronous to the scaled mileage,realizing the query of the active picture frames;the digital map query subsystem fulfills the map query,preview and spelling of digital map orthograph.

其中，地形图输入与维护实现了数字地图的格式转换、编辑处理以及空间数据的更新操作，解决了不同格式空间数据的互相转换问题；线路录象播放将线路录像数据作为系统的一种索引数据，活动影像的画面与里程相对应，实现了基于线路录像的播放、查询和检索的功能，实现了基于活动画面的查询检索功能；数字地图子系统完成了图形查询、数字地图与线路正射图像浏览、图幅拼接等功能。

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。

Thirdly, in order to manage these data better, the paper advances the organization methods of data of commixed Database of Geo-spatial Framework model by integrating some advanced database technologies such as RDBMS and the Spatial Database Engine, namely on the basis of database and the data of Geo-spatial Framework divided in a preceding part of this paper, it describes layer-delaminating, block-dividing, slice-connecting, map-dividing and BLOB etc. to organize spatial data, including DLG, DOM, DEM, and thematic data, taking example for the data of urban planning. At the same time it also realizes integrated management of these data.

然后，本文以管理这些地理空间框架数据为主要目标，集成关系数据库管理系统以及空间数据引擎等相关技术，提出了地理空间框架混合数据库数据组织方法，即以地理空间框架数据库为基础，以分类后的地理空间框架数据为对象，通过采用分层、分块、连片、分幅以及大二进制对象等方法对基础空间数据(包括数字线划数据、数字正射影像数据、数字高程模型数据)和专题数据进行统一组织，并实现了这些数据的关联一体化管理。

To deal with the problems and present situation of field data capture by computer in geological mapping in 20 years, this paper has created PRB digital mapping techniques to standardize the digital mapping process and discussed PRB mapping technique-method system, including PRB digital mapping techniques, the model of PRB data and the related process, combinational regulations of PRB process, common mechanism and basic procedure of PRB process, data processing and dictionary of PRB, three-class PRB system,...

从近 2 0年地质填图中计算机野外数据采集技术研究的现状和存在的问题入手，在确定地质填图空间数据表达的基础上，遵循传统地质填图的规律，在不约束地质学家地质思维的前提下，既能满足计算机处理的需要，又能保证地质工作者取全、取准各项地质观测数据，在描述各类地质信息空间关系的基础上，创建了数字地质填图过程标准化和规范化的PRB数字填图技术，并对构成PRB数字填图技术、PRB数据模型、PRB基本过程、PRB基本过程组合的规则、PRB过程的公共机制、PRB过程基本程式、PRB数据操作、PRB字典、三级PRB体系、PRB数据流&栈&、PRB数据质量定量评价体系的PRB数字填图技术与方法体系进行了讨论。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。