西北江三角洲来水来沙的非线性分形特征

根据西、北江干流高要、石角及西北江三角洲网河区顶点马口、三水四个水文站的流量和含沙量资料 ,应用非线性分形原理的R S方法 ,计算西北江干流及西北江网河区顶点四个水文站的流量、含沙量的赫斯特数H和分形维数D ;探讨西、北江干流来水来沙的分形特征及西北江三角洲的分水分沙规律。结果表明 ,流量的分维数略大于含沙量的分维数 ,三水站流量及含沙量的分维数与其上游的石角站流量、含沙量的分维数相差较大 ,与思贤的分水分沙造成西北江的水沙交换有关     

Extending the color gamut and dynamic range of an sRGB image using a residual image

Image sources, such as digital camera captures and photographic negatives, typically have more information than can be reproduced on a photographic print or a video display. The information that is lost during the tone/color rendering process relates to both the extended dynamic range and color gamut of the original scene. In conventional photographic systems, most of this additional information is archived on the photographic negative and can be accessed by adjusting the way the negative is printed. However, most digital imaging systems have traditionally archived only a rendered video RGB image. As a result, it is not possible to make the same sorts of image manipulations that historically have been possible with conventional photographic systems. This suggests that there would be an advantage to storing images using an extended dynamic range/color gamut color encoding. However, because of file compatibility issues, digital imaging systems that store images using color encoding other than a standard video RGB representation (e.g., sRGB) would be significantly disadvantaged in the marketplace. In this article, we describe a solution that has been developed to maintain compatibility with existing file formats and software applications, while simultaneously retaining the extended dynamic range and color gamut information associated with the original scenes. With this approach, the input raw digital camera image or film scan is first transformed to the scene‐referred ERIMM RGB color encoding. Next, a rendered sRGB image is formed in the usual way and stored in a conventional image file (e.g., a standard JPEG file). A residual image representing the difference between the original extended dynamic range image and the final rendered image is formed and stored in the image file using proprietary metadata tags. This provides a mechanism for archiving the extended dynamic range/color gamut information, which is normally discarded during the rendering process, without sacrificing interoperability. Appropriately enabled applications can decode the residual image metadata and use it to reconstruct the ERIMM RGB image, whereas applications that are not aware of the metadata will ignore it and only have access to the sRGB image. The residual image is formed such that it will have negligible pixel values for those portions of the image that lie within the sRGB gamut, and will therefore be highly compressible. Tests on a population of 950 real customer images have demonstrated that the extended dynamic range scene information can be stored with an average file size overhead of about 8% compared to the sRGB images alone. © 2003 Wiley Periodicals, Inc. Col Res Appl, 28, 251–266, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10160     

极大代数意义下幂矩阵的周期性特征

在分析一类离散事件动态系统的运行周期性及稳定性时,必须求解极大代数意义下矩阵的特征值。这一直被认为是十分困难的工作。直至目前为止,尚无一种能确定任一方阵全部特征值及特征向量的简易方法。本文对极大代数意义下任一方阵的幂矩阵的周期性特征进行了深入分析。本文的结果为寻求计算特征值及特征向量的新算法提供了十分有效的途径。     

调频步进信号处理方法探讨

调频步进信号是一种新的高距离分辨率信号。文章首先简要阐述了线性调频信号的处理过程；其次对比步进频率、线性调频步进信号的处理过程，得到一种新的处理方法-合成处理法，最后通过仿真论证其正确性。     

质子和中子的单粒子效应等效性实验研究

通过实验方法确定了高能质子和中子引起的单粒子效应等效关系，实验中采用金箔散射法降低了质子束流强度，并利用热释光剂量计（TLD）进行质子注量的监测，采用新研制的存储器长线实时监测系统，进行了64K位至4M位的SRAM器件单粒子效应实验，确定了两种粒子引起单粒子效应等效关系。     

DLL23XA双侧向测井仪的研制

以往双侧向测井仪动态范围小，测量精度低，为此开发了DLL23XA双侧向测井仪。该仪器主要单元采用厚膜电路，稳定性、一致性好；深、浅屏流源采用可变功率控制，提高了仪器的动态范围。仪器采用3506P例进行数据传输，可方便地配接各种地面系统。     

Locked discrete event systems: How to model and how to unlock

To model qualitative aspects of discrete event systems, i.e., the order of the events is of sole importance, we use a triple consisting of the set of all possible events (the alphabet), the set of all behavior (possible strings of events), and the set of all tasks (completed behavior). We use this view to model synchronous as well as asynchronous connection of systems. Moreover, it is easy to define notions like deadlock and livelock in this view. We give a method to construct a second system that, in connection with the original system, gets rid of its deadlock and/or livelock. A state-space representation is introduced. In this representation computations can be done effectively.     

离散事件动态系统的代数模型及其控制器的分析计算

本文在离散事件动态系统的Ｐｅｔｒｉ网图形描述的基础上建立了相应的代数模型，该模型可以用来计算无竞争无回路Ｐｅｔｒｉ网的“最大状态”；该“最大状态”的计算在本文给出的动态反馈控制器中得到了应用。     

扩展有限递归进程模型

主要讨论离散事件动态系统的建模问题。由ＫＩｎａｎ和ＰＶａｒａｉｙａ提出的有限递归进程（ＦＲＰ）是描述并发离散事件动态系统的有力工具，但在其ＦＲＰ中，没有定义对数据变量的操作和条件转移算子。本文扩展ＦＲＰ包括这两方面内容。最后举例说明扩展ＦＲＰ的描述能力。     

CAD^2B—一个计算机辅助数据库设计系统

本文介绍了一个用Ｔｕｒｂｏ Ｃ语言在ＡＳＴ－２８６机器上实现的计算机辅助数据库设计系统ＣＡＤ＾２Ｂ。该系统提供了人机交互的环境，供设计者进行概念模型设计，并自动完成从概念模型逻辑模型的映射，创建满足规范化要求的关系表。该系统采用的概念模型是引入了事件和时间的扩展了的实体关系模型。该模型既能充分反映应用环境的静态和动态语义，又是向关系模式转化的基础。