改进BP3参数对网络识别能力影响的研究

分别从BP网络的学习步长,学习速率自适应调整算法的参数,动量法和自适应学习速率结合起来算法的参数3方面讨论了改进BP参数对网络识别能力的影响;在确定BP网络的隐含层节点个数的过程中提出了BP神经网络自适应学习算法,使得隐层节点的选取动态实现。仿真实验表明,该改进是可行的。     

一种基于神经网络的入侵检测技术

应用神经网络技术不仅能识别已知的网络人侵行为,而且也能识别许多未知的网络入侵的变种.BP神经网络是一种成功的神经网络技术,然而,标准BP算法学习速率固定,不能根据实际情况动态改变学习速率.为了自适应当前网络学习的状况,提高网络的收敛速度,提出了一种基于综合增加动量项与自适应调节学习速率相结合的改进BP算法,可以满足入侵检测分类识别的需求.选用Kddcup 1999 Data网络连接数据集进行特征提取和预处理之后,送人神经网络进行训练和测试,得到较高的检测率和较低的误报率.实验表明,基于改进的BP神经网络的入侵检测方法是有效的.     

醇解度预测的神经网络模型研究

针对聚乙烯醇生产过程的醇解度预测问题,建立神经网络模型;对醇解度的影响因素进行了研究,讨论了输入层、输出层、隐含层等神经元的设置及网络训练的参数,比较了梯度下降BP算法、动量-自适应学习速率调整算法、Levenberg-Marquardt BP算法三种不同的训练算法在本问题上的优劣,并与RBF网络相比较,综合考虑训练时间、训练精度、泛化能力等条件,动量一自适应学习速率调整算法是最适合醇解度预测的,并基于动量-自适应学习速率调整算法建立了神经网络模型;将模型应用于醇解度预测系统,系统实际运行情况表明,利用神经网络模型预测醇解度是可行有效的.     

改进BP算法在热流传感器温度补偿中的应用

针对帕尔贴( Peltier)热流传感器存在温度漂移问题,提出了一种基于改进BP神经网络的温度补偿模型.采用BP算法的多层前馈网络建立起热流传感器输出电压、实验温度与输入热流间的映射关系,又通过增加动量因子和自适应调节学习率来提高网络的收敛速度与增强网络平稳性.研究结果表明:动量因子-自适应学习率算法温度补偿模型效果明显.     

自适应动量项BP神经网络盲均衡算法

为了消除数字信号在传输过程中产生的码间串扰,使得接收端能够正确解调,对信道畸变进行有效补偿,在基于动量项BP神经网络盲均衡算法的基础上,提出一种能够自适应调节BP神经网络动量项的盲均衡算法.该算法根据盲均衡过程中误差函数的变化情况,自适应调节BP神经网络的动量项,充分发挥动量项在避免网络训练陷于较浅的局部极小点的优势.仿真实验结果表明,该算法在稳定性及收敛性能上均优于固定动量BP神经网络盲均衡算法.     

一种基于神经网络的入侵检测系统研究

提出在入侵检测系统模型设计中引入神经网络技术,建立了一个基于神经网络的入侵检测系统模型。针对传统BP算法存在的一些固有缺点,提出增加动量项与自适应调节学习速率相结合的改进算法,一定程度上克服了BP神经网络存在的问题。实验结果表明,基于改进的BP神经网络的入侵检测方法具有良好的检测性能。     

修正激励函数的BP算法的研究

本文对基于梯度下降的标准BP算法进行了深入研究,提出了修正激励函数的BP算法,它能有效克服标准BP算法中Sigmoid函数的不足,加快网络学习速率。在模型预测控制的建模和预测中,将基于该算法的神经网络与基于标准BP算法的神经网络、基于带动量项的BP算法的神经网络、基于自适应调整学习率BP算法的神经网络、基于自适应调整学习步长和动量项4算法的神经网络进行仿真比较,它在预报准确率和学习速度方面都取得了令人满意的结果。     

神经网络在化工过程故障诊断中的应用

针对现代复杂的化工生产过程,提出一种基于神经网络的故障诊断方法。并分别将典型的BP算法和改进后的BP算法用于TE（Tennessee Eastman）模型的故障诊断中。经过诊断结果的比较,得出标准的BP算法在实际应用中具有收敛速度慢等缺点;自适应学习速率动量梯度下降的BP算法以及用L-M（Levenberg-Marquardt）法先对BP网络进行优化的BP算法具有收敛速度快、不易陷入局部极小值等优点,其中又以L-M优化BP算法效果最好。结合rIE模型的仿真结果可以看出,L-M优化BP算法在工业实际中具有很大的优势。     

基于样本自组织聚类的BP神经网络预测模型

根据实际应用中神经网络训练样本通常具有内在特征和规律性,提出一种基于样本自组织聚类的BP神经网络预测模型。通过自组织竞争网络的聚类特征,改善样本训练对BP网络性能的影响。BP神经网络采用收敛速度较快和误差精度较高的动量—自适应学习速率调整算法。并通过基于这种模型的空气质量预测实验,表明基于样本自组织聚类的BP神经网络预测模型首先会提高收敛速度,其次会减少陷入局部最小的可能,提高预测精度。     

基于分层自适应学习率的改进BP算法

在自适应学习率算法的基础上提出一种新的BP网络改进算法——分层自适应学习率附加动量项算法。仿真结果表明该算法较之自适应学习率算法能进一步提高网络的学习速度。     

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.