数字

The first kind of the digital signature schemes is based on the discrete logarithm problem and second kind of the digital signature scheme is based on discrete logarithm and factorization problem, the third kind of the digital signature schemes is based on quadratic residue problem.

本文第一章对数字签名方案进行分类，根据数字签名方案所基于的数学问题，将签名方案分为：基于离散对数问题的数字签名方案，基于素因子分解问题的数字签名方案和基于二次剩余问题的签名方案。

The construction of numeral abbreviation can be roughly grouped into four types: subordination, coordination, subject+predicate and verb+object. Among them, subordination occupies the main part. Numeral abbreviation can be derived from either extracting the first, the middle or the last morpheme from its original words or generalizing them. Numeral abbreviation consists of four classes: word, phrase, sentence and text in terms of its original words. Most numeral abbreviations are disyllabic and quadrisyllable, and only a small number of them are trisyllabic and polysyllabic.

数字缩略语的结构有类化的特点，包括偏正式、并列式、主谓式、动宾式等，其中以偏正式为主；在抽取方式上，数字缩略语有抽头式、取中式、取尾式和统括式；从缩略的对象上看，数字缩略语的缩略可分为词、短语、句子和篇章四个层次；在音节分布上，数字缩略语以二、四音节为主，三音节和多音节为辅。

The main features of the system are: the communications line is not only used for data transmission but also responsible for the system control and management; only one analogue to digital converter is needed for the whole system; a digital trimmer which is analogous to the adjustable resister in function is installed to each sub—system.

本文所进行的数字型条干均匀度测试仪的系统设计，采用了多微处理器的分布式并行结构，提出了一种数字信号的总线结构，采取了数据预处理和数字微调等措施，其主要特点为：半双工异步通信线不但用于数据传输，而且还负责系统的控制和管理；整个系统只需一路模数转换器；各子系统均设有数字微调装置，其功能类似于模拟电路中的电位器，可独立进行参数调整。

The design of home control system using ITV SDF middleware present in this thesis will have many meanings to the development of digital home application using ITV SDF middleware.

本文提出的基于 SDF 数字家庭中间件的数字家居软件设计与实现，对开发基于 SDF 数字家庭中间件的数字家居应用有较大的指导意义。

The major findings of this research can be summarized as follow:1 The comparison of USPED model-estimated amounts of soil erosion based on four different scales of DEMs (1:250,000, 1:50,000, 1:10,000, and 1:5,000) indicates that 1:50,000 -scale DEM is almost as good as higher-resolution DEM data in providing needed topographic information for assessing soil erosion, whereas 1:250,000-scale DEM underestimates soil erosion mainly because rill erosion and sheet erosion are greatly underestimated.2 Since precipitation is the most important forcing factor for soil erosion, the accuracy of soil-erosion estimates understandably relies on the adequacy of spatially distributing point-observed precipitation data.

取得的主要成果如下：(1)基于四个尺度(1∶250，000，1∶50，000，1∶10，000，and 1∶5，000)的数字高程模型和USPED模型计算的土壤侵蚀结果对比表明，1∶50，000的数字高程模型与更高分辨率数字高程模型提供了几乎一样的用以估算土壤侵蚀所需的地形信息，而1∶250，000的数字高程模型，由于过低的估算了细沟侵蚀和片蚀，从而过低的估算了土壤侵蚀的总量。

The digital speciemen image of adult Helicoverpa armigera Hubner was acquired using a digital camera in an image acquisition environment.Several methods of image enhancement were covered, including linear smoothing, median filtering, linear greylevel transformation, contrast stretching, image inversing and histogram equalization. Results demonstrated that these methods evidently enhanced the speciemen image of H.

digital image ；本研究以棉铃虫成虫标本作为数字图像源，设计了图像获取环境，以数码相机做为数字图像获取设备获得了棉铃虫成虫的数字图像，介绍了昆虫数字图像增强的方法，包括图像的线性平滑、中值滤波平滑、线性灰度变换、对比度拉伸、图像求反以及直方图均衡化等增强方法，证明这些方法对棉铃虫图像具有明显的增强作用。

Taking use of the redundant data and randomicity of the digital products, the digital watermarking technology embeds the unperceivable but recognizable secret information--watermark containing the copyright information into the digital products, which can protect the copyright and integrality of the digital products.

数字水印技术利用数字作品中普遍存在的冗余数据与随机性，向数字作品中加入不易察觉但可以判定区分的秘密信息－水印，从而保护数字作品版权或完整性。

Altera Corporation system to the Cyclone FPGA series of digital platform, microprocessor, bus, Digital Frequency Synthesizer, memory and I / O interface hardware concentrated in an FPGA, the use of direct digital frequency synthesis technology and digital modulation waveforms required to achieve the rise, Using FPGA ROM storage of the DDS waveform table, and make full use of on-chip resources, improve the system's accuracy, stability and robustness.

系统以 ALTERA公司的 Cyclone 系列 FPGA 为数字平台，将微处理器、总线、数字频率合成器、存储器和 I/O 接口等硬件设备集中在一片 FPGA 上，利用直接数字频率合成技术、数字调制技术实现所要求波形的产生，用 FPGA 中的 ROM 储存 DDS 所需的波形表，充分利用片上资源，提高了系统的精确度、稳定性和抗干扰性能。

With the analysis of present copyright protection scheme, contrapose the discoverable weakness and deficiency, this paper propose a secure and fair digital copyright protection protocol based on digital watermarking and digital signature.

通过对目前已有的数字版权保护协议的分析，针对发现的弱点和不足，结合数字水印技术和数字签名技术，给出了一个安全的、公平的数字版权保护协议。

With the analysis of present copyright protection scheme, contrapose the discoverableweakness and deficiency, this paper propose a secure and fair digital copyright protectionprotocol based on digital watermarking and digital signature.

通过对目前已有的数字版权保护协议的分析，针对发现的弱点和不足，结合数字水印技术和数字签名技术，给出了一个安全的、公平的数字版权保护协议。

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。