基于XML文件组织的嵌入式监控组态软件设计

为了实现监控组态软件对所有监控记录的存储、管理和报警等功能,弥补终端设备无法存储大量记录的缺陷,在分析XML文档存取与解析的基础上,提出了一种软件层次清晰、使用XML作为数据中心格式、对操作系统无依赖的嵌入式组态监控软件的总体设计方案.该方案主要阐述了XML文件的组织方案、上位机监控组态控制平台的数据库设计、组态控制及网络通信中发送与接收数据包的设计与实现,并通过大量充分测试,表明了该方案的可行性和有效性.     

一种改进的基于LZW压缩编码的可逆信息隐藏算法

针对HPDH-LZW算法在隐藏信息时未能充分利用压缩编码数据空间问题,通过对压缩编码数据空间进行细分,在不同的子空间里隐藏不同数量的秘密信息,实现了一种改进的基于LZW压缩编码的可逆信息隐藏方法。实验表明,与原算法相比,本算法没有增大压缩文件,也没有增加计算复杂度,但具有更大的信息隐藏容量。     

Recursive parser optimization by rewriting context-free grammars

The analysis of programming languages is a fundamental activity in the process of comprehending, maintaining, documenting and reengineering old software. However, the analysis may sometimes be inefficient because of the parsing methodology adopted. Prolog parsers, for instance, have two main drawbacks: the time spent on extracting information as a result of the backtracking mechanism, and the large memory occupation involved. This paper presents an algorithm that optimizes a top-down parser by imposing a set of rules on the grammar to be analyzed. A methodology is then defined for rewritting a context-free grammar (LL(n) n > = 1), and a tool that can achieve this is illustrated. This tool, called FACTOTUM, has been implemented in LPA Prolog, and works on a PC (IBM-MSDOS) through the Windows medium. FACTOTUM is composed of nearly 250 productions, and is an important part of another reverse engineering tool called RE_Tool (Giannone and Maresca, 1995) which can analyze codes in a multilanguage environment. RE_Tool has been implemented in the software engineering laboratories of DIS at the University of Naples Federico II, where it is currently under experimentation.     

Pallel parsing of tree languages for syntactic pattern recognition

Several software engineering techniques are proposed for the implementation of a more efficient Error-Correcting Tree Automata (ECTA). The production rules of a tree grammar are transformed into suitable internal codes by a lexical analyzer during the preprocessing phase, thus, several more efficient searching algorithms such as binary search, hashing techniques or table-lookup can then be used to improve the parsing efficiency. A parallel parsing algorithm of tree languages is then introduced. Comparisons of speed gain vs overhead of parallel algorithms are presented. Illustrative examples include the application of the proposed parallel algorithms to the interpretation of LANDSAT data and the discrimination of textures. Simulation results of the proposed parallel algorithm are presented.     

基于DCT的频域块匹配法及其实现

用软件实现在低码率信道上的实时视频编解码是图像压缩领域的研究热点,该文就此提出了一种基于离散余弦变换（ＤＣＴ）系数的频域块匹配法,通过引入阈值矩阵,降低了运动估值算法的运算量,提高了搜索效率。计算机仿真表明,该算法可在ＰＣ机上用软件实时实现,具有较好的实用价值。     

一种基于DCT的频域运动估值算法

用软件实现在低码率信道上的实时视频编解码是图象压缩领域的研究热点，本文就此提出了一种基于离散余弦变换（DCT）系数的频域块匹配法，通过引入阈值矩阵，降低了运动估值的运算量，提高了搜索效率。计算机仿真表明，该算法可在PC机上用软件实时实现，具有较好的实用价值。     

超声信号采集模块的设计

一种超声信号数据采集的模块,完成高频超声信号的高速采集;简单的介绍了该模块的硬件及软件设计;其硬件模块具体包括通过PROTEL软件设计的A/D采样硬件电路,USB系统的连接电路;软件模块包括利用Verilog语言完成FPGA状态机来控制A/D采样,针对具体功能的USB固件初始化程序,以及上位机对USB系统上传数据进行读取以及将所读取到的数据进行的图形显示;实验结果显示可以将采集到的数据高速传输至上位机后进行图形显示分析.     

A high-performance reversible data-hiding scheme for LZW codes

Hiding a message in compression codes can reduce transmission costs and simultaneously make the transmission more secure. In this paper, we propose a high-performance, data-hiding Lempel–Ziv–Welch (HPDH-LZW) scheme, which reversibly embeds data in LZW compression codes by modifying the value of the compression codes, where the value of the LZW code either remains unchanged or is changed to the original value of the LZW code plus the LZW dictionary size according to the data to be embedded. Compared to other information-hiding schemes based on LZW compression codes, the proposed scheme achieves better hiding capacity by increasing the number of symbols available to hide secrets and also achieves faster hiding and extracting speeds due to the lower computation requirements. Our experimental results with the proposed scheme have confirmed both its high embedding capacity and its high speed when hiding and extracting data.     

A Fractal Compression Algorithm Based on Collage Distance Estimating and Compensating

A new fractal image compression scheme based on collage distance is explained, which can provide of the scheme two different compression codes containing their own unique collage distance sets and different types of similar transforms. The analysis and applications of the scheme indicate that it can be adopted as a suitable alternative for balancing between the distortion measure and compression ratio occurring in ordinary fractal compression method.     

A large‐alphabet‐oriented scheme for Chinese and English text compression

In this paper, a large‐alphabet‐oriented scheme is proposed for both Chinese and English text compression. Our scheme parses Chinese text with the alphabet defined by Big‐5 code, and parses English text with some rules designed here. Thus, the alphabet used for English is not a word alphabet. After a token is parsed out from the input text, zero‐, first‐, and second‐order Markov models are used to estimate the occurrence probabilities of this token. Then, the probabilities estimated are blended and accumulated in order to perform arithmetic coding. To implement arithmetic coding under a large alphabet and probability‐blending condition, a way to partition count‐value range is studied. Our scheme has been programmed and can be executed as a software package. Then, typical Chinese and English text files are compressed to study the influences of alphabet size and prediction order. On average, our compression scheme can reduce a text file's size to 33.9% for Chinese and to 23.3% for English text. These rates are comparable with or better than those obtained by popular data compression packages. Copyright © 2005 John Wiley & Sons, Ltd.     

基于 DCT 频域条件帧间补偿法的视频编码方案及其实现

运动图象的压缩是实现多媒体通信的关键技术之一。本文提出一种基于离散余弦变换（ＤＣＴ）系数的条件帧间补偿法及其视频编码方案。该算法利用ＤＣＴ变换的特点和人眼视觉特性，快速高效地对运动图象进行编码。由于运算量低，该算法可以在ＰＣ机上用软件实时实现，适用于基于ＰＣ平台的可视电话、会议电视和可视多媒体通信系统。     

地铁迷流实时监测系统软件的设计与实现

详细阐述了地铁迷流上位机监测软件的VC 实现,包括界面设计、数据表单设计、通信协议的制定以及串行通信的实现.介绍了ADO访问数据库技术、VC 提供的串行通信控件MSComm的用法以及实时动态曲线的实现;分析了软件的具体设计思路并给出了主要程序代码.     

基于DCT频域条件帧间补偿法的视频编码方案及其实现

运动图象的压缩是实现多媒体通信的关键技术之一。本文提出一种基于离散余弦变换系数的条件帧间补偿法及其视频编码方案。该算法利用DCT变换特点和人眼视觉特性，快速高效地对运动图象进行编码。     

A secret image sharing scheme based on piecewise linear chaotic map and Chinese remainder theorem

In this paper, a secret image sharing scheme, by combining arithmetic compression coding and Chinese remainder theorem (CRT) is proposed. It is well known that arithmetic compression coding method for image has a good compressibility, and it can reduce the size of the shadow image, which consists of sharing values. Usually, a smaller shadow image is convenient to store and transmit. The piecewise linear map is applied to design compression coding scheme, which has the same properties as the conventional arithmetic compression coding. The CRT is used to construct the sharing scheme for compression codes. Meanwhile, it also has encryption effects in the process of sharing. Finally, the security and the effectiveness of the secret image sharing scheme are confirmed by some computer simulation results.

     

基于智能Agent的实体关系模型多程序代码自动生成方法研究

基于智能Agent理论,本文提出了一种通过人机交互方式自动将实体关系模型（Entit y-Relation,ER）生成多种应用程序语言代码和数据库语言代码的智能化方法体系框架, 简要介绍了利用基于该方法的软件工具将ER模型生成程序代码的过程．     

Using contexts and R-R interval estimation in lossless ECG compression

The paper presents a new lossless ECG compression scheme. The short-term predictor and the coder use conditioning on a small number of contexts. The long-term prediction is based on an algorithm for R-R interval estimation. Several QRS detection algorithms are investigated to select a low complexity and reliable detection algorithm. The coding of prediction residuals uses primarily the Golomb-Rice (GR) codes, but, to improve the coding results, escape codes GR-ESC are used in some contexts for a limited number of samples. Experimental results indicate the good overall performance of the lossless ECG compression algorithms (reducing the storage needs from 12 to about 3-4 bits per sample). The scheme consistently outperforms other waveform or general purpose coding algorithms.     

基于CUDA平台的规则LDPC码的译码实现研究

低密度奇偶校验(LDPC)码性能优越,允许全并行高速译码,已经在个人数字设备、移动无线通信等领域显示出了很大的应用价值,极可能取代Turbo码成为第四代移动通信的首选编码方案。NVIDIA公司的CUDA是一种新的用于GPU通用计算的软硬件架构。基于CUDA平台程序员可以写出C风格的代码来启动大量的GPU线程并行工作。基于CUDA平台提出和研究一种AWGN信道下的规则LDPC码的译码实现方案。仿真实验对LDPC码译码的CPU实现和CUDA实现的性能作了详细比较。研究表明CUDA能够带来明显的性能提升。     

基于最大秩距离码的私钥加密方案

Jordan和Rao基于纠错码提出了一种私钥加密方案,通过安全性分析可知,基于大数选举方法,此方案中的秘密矩阵能有效地获得。Gabidulin于1985年提出了秩距离码及最大秩距离码的理论,由于秩范数和秩距离码的特点,利用秩距离码构造密码系统,可用比较小的参数获得比较大的工作因子。Gabidulin,Paramonov和Tretjakov基于最大秩距离码提出了一种新的McEliece公钥密码系统,该文基于最大秩距离码提出了与其稍有不同的一种私钥加密方案。讨论了它的可行性及安全性,并证明了它比基于最大秩距离码的上述公钥密码系统更安全。     

An optimal high capacity reversible data hiding scheme using move to front coding for LZW codes

Reversible Data hiding techniques reduce transmission cost as secret data is embedded into a cover image without increasing its size in such a way that at the receiving end, both secret data and the cover image can be extracted and recovered, respectively, to their original form. To further reduce the transmission cost, the secret data can be embedded in the compression codes by some popular reversible data hiding schemes. One of the popular and important reversible data hiding method is high- performance data-hiding Lempel–Ziv–Welch (HPDH-LZW) scheme which hides the secret data in LZW codes. In this paper, the HPDH-LZW scheme is modified in order to increase its hiding capacity and compression ratio. First, the proposed work modifies the Move to Front (MTF) encoding technique to hide the secret data and also to increase the similarity among the element of the cover media. Then, LZW encoding technique is applied on the resultant cover data to obtain LZW codes, which are used to hide further secret data. Experimental results show that the proposed scheme has significantly increased the data hiding capacity and have good embedding and extraction speed in comparison to other state of the art schemes.