一种分段拟合的网络测量数据压缩方法

网络原始测量数据由于数据量很大,不方便存储,为了便于存储并保证数据有效性,本文研究了数据压缩策略,提出了一种基于最小二乘法的分段二次曲线拟合压缩模型,给出了最小二乘解的算法。通过仿真实验与最小二乘拟合和分段线性插值进行比较,分段二次曲线拟合压缩模型能够在减少了数据存储量的基础上实现对网络性能指标的准确反映,能及时发现网络性能的异常变化。     

高次曲线最佳节点分段拟合法

高次曲线最佳节点分段拟合法,是指拟合曲线段数为两段,而分段点(即节点)和方程次数可随精度要求进行自适应选择的方法。本文介绍了根据最小二乘原理,用分段高次多项式曲线进行数据拟合时求最佳分段点和最佳系数的思想、数学模型和具体实现步骤,并通过实例验证了该方法的有效性。     

二次NURBS曲线及曲面权重系数的研究

针对二次NURBS曲线及双二次NURBS曲面的权重系数计算方法进行了研究,提出了一种新的二次NURBS曲线、曲面的权重系数计算方法.该方法改进了现有方法中数据规范化、相关矢量和相关矩阵的计算方法,去掉了在计算过程中对相关矩阵的求逆,并且增加了一项顶点系数.与现有方法相比,该方法能够更快地计算出每一个控制顶点的权重系数.采用几个经典的数值算例对该方法进行了验证,结果表明用该方法计算的权重系数去进行曲线、曲面的拟合,能够得到比现有方法更高的拟合精度.     

利用二次B样条曲线逼近的图像压缩方法

提出了一种基于Hilbert扫描和二次B样条曲线逼近的图像压缩方法。首先利用Hilbert扫描曲线将二维数字图像转化为一维的灰度序列;然后采用二次B样条曲线对数据进行分段逼近,同时利用逼近的最大绝对误差小于最大允许误差来确定最终分段;最后对每段数据的逼近参数进行编码。实验结果表明,该方法获得的压缩效果较好,且计算量适中,是一种简单有效的数字图像压缩方法。     

支架压力监测数据分段拟合方法

针对支架压力监测系统应用于超长工作面时,受总线查询周期限制而难以兼顾监测支架压力中的突发奇异信号与数据实时传输的问题,提出一种支架压力监测数据分段拟合方法。该方法按照支架压力监测系统1个查询周期进行数据分段,在某个分段内如果数据量小于拟合系数量,则直接传输数据;如果数据量不小于拟合系数量,则进行数据的多项式拟合,获取拟合系数并只传输拟合系数。实验结果表明,该方法大大减少了传输数据量,又不丢失重要数据,同时实现了每个查询周期固定数据传输量,便于数据传输管理。     

平面上散乱数据点的二次曲线拟合

基于代数距离定义目标函数，在6种不同约束条件下得到6条基本二次曲线，最终的拟合二次曲线由6条基本二次曲线系数加权平均产生．用实例对该方法和其他几种方法拟合曲线的误差作了比较，并讨论了基于代数距离目标函数的几何意义．     

基于序列图像的二次曲面体轮廓曲线匹配

该文提出一种二次曲面体轮廓曲线匹配方法。首先提取图像的轮廓边缘,用分段二次曲线描述边缘,得到每段曲线的坐标点集并进行标准化;再对经标准化后的坐标进行二次曲线拟合,得到二次曲线方程的参数;最后通过二次曲线的三个不变量来进行曲线匹配。实验表明,该方法能够有效地匹配二次曲面体轮廓边缘,并具有较高的匹配精度。     

基于动态规划算法的矢量压缩方法研究与改进

将动态规划算法应用于矢量数据压缩是一种非常有效的优化压缩方法,可以得到压缩误差最小的压缩曲线,但是会导致局部失真明显。针对该缺点提出一种改进算法,通过在动态规划算法执行过程中设定阈值限制最大位移来防止局部失真,同时对A. KOLESNIKOV等提出的原动态规划算法公式的错误进行了纠正。实验表明,改进算法在保持原算法优势的同时,可以较好地解决压缩曲线局部失真问题。     

RWM&DEWS数据二次压缩算法研究

对柑橘实时水分监控与旱情预警系统中的数据参数进行拟合分析,在探讨SDT和LZW 2种压缩算法的基础上,提出一种二次压缩算法:第1次压缩采用基于SDT算法思想的甲均值方法;第2次压缩采用改进的LZW算法实现.对压缩效果进行测试,仿真实验证明,在相同的硬件和软件环境下,该算法能实时、高效地压缩数据.     

一种高精度的自动化数据处理方法

提出并使用以分段最小二乘多项式迭代光顺和最小二乘三次样条光顺为核心的自动化数 据处理方法处理光滑物体表面的测量数据.该方法在不影响测量结果准确值的前提下,能够 达到消除其中的统计误差和使测量数据合理化的目的.     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.