基于1D-CNN-LSTM的特定辐射源识别方法

特定辐射源识别（Specific Emitter Identification,SEI）是指利用雷达指纹特征确定产生信号的辐射源个体。通过对雷达辐射源的识别,可以有效区分出敌我雷达,保证雷达信息的安全性,这在电子战中具有重要的军事意义。目前传统分类识别方法存在指纹特征提取困难,指纹识别正确率低等问题。本文提出了一种基于1D-CNN-LSTM(One Dimensional Convolutional Neural Network Long Short Term Memory)特定辐射源识别方法。该方法直接使用采集到的信号的同向相交分量（Inphase/Quadrature. I/Q）数据进行信号的特征提取,并实现了对于来自不同辐射源个体信号的识别与区分。该模型兼具卷积神经网络与长短时记忆网络的优点,它可以在提取抽象特征的同时进行时序分析。实验结果表明,1D-CNN-LSTM网络能够在复杂的电磁环境下实现对特定辐射源个体的更好识别。     

基于星座轨迹图的射频指纹提取方法

无线设备的接入安全是当今无线网络安全的一个严重挑战。基于射频指纹的物理层安全技术是解决无线设备接入安全的一个有效途径。在不同于已有的基于瞬态响应和稳态响应的射频指纹特征提取方法上,本文提出了一种使用星座轨迹图（CTF,Constellation Trace Figure）的射频指纹提取方法。在获得的星座轨迹图上,进一步通过K均值聚类提取射频指纹特征并进行设备身份识别。在理论阐述的基础上,本文通过在实际无线通信系统中提取射频指纹特征并进行无线设备身份识别,验证了提出方法的可靠性与实用性。使用基于星座轨迹图的射频指纹特征提取方法不需要获得设备发送信号的先验信息就可以快速获得无线设备唯一的射频指纹特征,可以被用于物理层安全以及无线接入设备的身份识别及认证。     

特定辐射源指纹识别的无线信息安全新理论

特定辐射源指纹识别技术指的是利用无线网卡或者芯片卡等电信号或磁信号中所蕴含的"指纹"特性来进行个体身份识别的技术。它所依据的是"没有两片相同的树叶"及对电磁辐射源识别要细化到个体的需求,达到独一无二的识别。基于特定辐射源指纹识别技术有望颠覆现有的基于密钥、数字证书等的无线信息安全机制,彻底解决信息安全领域难题等具有重大意义,在交通、金融、安保等领域的信息安全防护具有极其广阔的市场前景。本文以应对无线网络、以及磁条、信用卡等信息安全面临的重大安全隐患和威胁为目标,深入探讨基于特定辐射源指纹识别的无线信息安全技术的标准体系建设、核心关键技术攻关、应用解决方案设计等方面的研究,提出建立全新的无线信息安全防护机制,推广应用基于特定辐射源指纹识别的信息安全产品,整体提升无线信息安全水平。     

计算机电磁指纹提取和识别技术研究

计算机电磁泄漏引发的信息安全问题日益严峻。计算机除了会通过电磁波泄漏处理的信息内容之外,也会泄漏反映计算机个体唯一性的指纹特征,称为电磁指纹。由于内部硬件结构与工艺差异,不同计算机个体具有不同的电磁指纹。为此,分析了计算机电磁指纹产生的原因及表现形式,构建简化的计算机电磁泄漏信号产生模型,并基于产生模型将线性预测分析算法应用于计算机电磁指纹提取,最后基于电磁指纹实现计算机身份唯一性鉴别。分析结果表明,利用线性预测系数可以在复杂电磁环境中成功鉴别出计算机个体。     

指纹和声音自动识别系统的设计与实现

为了快速和准确地鉴别有关人员的身份,开发一个指纹和语音自动识别系统。该系统通过采集指纹图像和语音信号,采用参考模型和相似度计算分别实现了指纹和语音识别。实验结果表明该系统不仅能自动地识别指纹和语音,而且还能实时地将识别结果与指纹和语音数据库进行比对,从而迅速地获得被识别人员的身份信息。该系统在监控出入境关口、机场车站、机关大院、住宅小区、以及刑事侦察等场合有着广泛的应用前景。     

基于设备与信道特征的物理层安全方法

接入安全与数据保密是无线网络安全性和保密性的两个最重要的因素.然而,基于计算安全的身份认证及保密通信方法在未来信息化系统中面临巨大挑战.与此同时,基于信息论安全的物理层安全为身份认证和保密通信开辟了新的思路.本文综述了近年来基于设备与信道特征的物理层安全方法的研究进展.利用无线通信设备、信道的特性可以从物理层实现设备身份的识别与认证以及密钥的分发与更新,同时具备高度安全性与使用便捷性.其中,设备指纹方法从发射信号中提取发送设备的特征,作为设备身份的唯一标识,从而准确识别不同发射源个体.指纹的唯一性、鲁棒性、长时不变性、独立性、统一性和可移植性是设备指纹身份认证的依据.而基于信道特征的密钥生成方法则从接收射频信号中提取互易的上下行信道的参数,转化为对称密钥,实现一次一密的安全传输.同样地,密钥的一致性、随机性、防窃听性则是反映无线信道密钥生成方法性能的关键要素.本文对设备指纹与信道密钥的关键要素归纳分析,并指出目前存在的几类难点问题.最后,本文讨论了在未来移动通信中该技术新的应用场景.     

基于随机森林的5G无线通信信号弱覆盖区域识别方法

目前,5G无线通信信号弱覆盖区域多采用单层级的识别模型,能够在合理范围内获取识别结果,但是精准度不高,导致误识率增大,因此提出对基于随机森林的5G无线通信信号弱覆盖区域识别方法的分析与研究。首先,对信号识别的需求和标准进行数据采集与识别环境预处理,设定定向识别节点;其次,综合随机森林技术,构建多层级的信号识别结构,提升识别结果的精准度;最后,构建随机森林通信信号识别模型,采用多阶信号集成处理实现区域识别。测试结果表明,本文所设计的随机森林通信信号弱覆盖区域识别测试组最终得出的误识率相对较低,表明在实际应用过程中识别速度快、误差可控、识别范围较大,具有实际的应用价值。     

基于指纹识别的通信电台识别仿真算法研究

研究电台准确识别的问题。在准确跟踪敌台活动、检测有效信息的过程中,由于信号受到哭声影响,实现识别较难。当待识别电台是相同调制模式和型号的不同电台个体,发射信号的差别非常细微。传统的关于暂态信号的识别方法是利用瞬间的暂态信号提取细微特征信息,造成信号的信噪比不高,不能正确识别电台信号。为了解决上述难题,提出了应用电台指纹的电台识别技术,通过对电台的稳态信号进行分析,计算信号的双谱特性,采用方形双谱和核主元分析算法,提取出信号中细微的指纹信息,通过分析电台的指纹信息完成电台的识别。实验表明,这种方法能够准确将差别细微的电台识别出来,避免传统方法信噪比不高的问题,保证了电台识别的准确率,取得了满意的结果。     

融合压缩感知的指纹信息密度凝聚定位算法

针对传统指纹定位方法指纹库庞大臃肿、信息冗余,数据处理机制单调的问题,提出了一种融合压缩感知的指纹信息密度凝聚定位算法(Fingerprint Information Density Aggregation Positioning Algorithm based on Compressed Sensing,FIDA),实现了压缩采样、信号恢复到指纹建库、在线定位的双领域交叉映射,两者互补增益有效提升了系统定位能力。由空间特征修正聚类算法完成区域模糊划分,自适应场景特征并包容区域边缘失配RP;从有效性、区分度和可测性多尺度综合评价并筛选区域最优AP子集,以凝聚信息密度。定位匹配选择稀疏贝叶斯算法削弱指纹相关性影响,引入信息序列提升近邻RP权重。实验结果表明,论文所提方案精简指纹信息效果良好,能够有效凝练指纹库价值信息。定位精度显著优于本领域算法,相比传统定位算法仍具有一定优势,具备较高的潜力和应用价值。     

基于方向图的动态阀值指纹信息提取识别研究

研究了指纹身份信息识别优化问题。由于在进行指纹识别时,指纹图像容易被噪声干扰,针对传统的指纹识别算法由于噪声的干扰,影响了指纹特征提取准确度。为了有效的解决上述问题,提出了一种新的方向图动态阈值指纹身份特征提取识别算法。首先分析指纹图像中存在的各类噪声的拓扑结构,然后对指纹图像预滤波处理,采用新的方向图动态阈值图像滤波和指纹图像二值化处理,最后得到二值化细化处理后的指纹图像。仿真结果表明,改进算法是一种有效的滤除指纹细节伪特征点的方法,可以有效的提高指纹信息提取识别的准确度。     

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.