共生视域下河北工业遗产数字化保护系统研究

文中从数字化的深度和广度两个方面,将工业遗产数字化保护划分为4个阶段,即基础信息化、应用数字化、全面系统化和共生视域下的智慧生态化。随后围绕共生视域,从数字化保护、文化遗产等方向进行了研究,发现可以考虑以数字孪生技术为依托,实现工业遗产数字化保护。基于此,文中搭建了一款基于数字孪生的工业遗产数字化保护系统,该系统包含感知层、数据层、运算层、功能层、应用层等。最后,以该系统为依托,构建了河北工业遗产综合服务体系,希望能为工业遗产的数字化保护提供一定的借鉴与参考。     

移动通信系统系统级仿真中慢衰落相关性的研究

本文基于前人研究的两种慢衰落相关模型提出了一种新的慢衰落相关模型，并通过仿真对该模型进行了验证，结果表明该模型内时包含上述的两种慢衰落相关性，用一个模型同时实现了两个相关模型。该模型较之前人提出的慢衰落相关模型更为全面和接近实际。     

PAM decomposition of M-ary multi-h CPM

It is known that any multilevel continuous phase-modulated (CPM) signal with a single modulation index can be exactly represented by a sum of pulse-amplitude modulated (PAM) waveforms. In this paper, we show how multi-h CPM signals can also be represented in this manner. The decomposition is presented in general terms as a function of the alphabet size, modulation indexes, and phase pulse of the CPM scheme. The number of pulses required to exactly construct the signal is shown to increase over that previously given for single-h schemes; this increase is in proportion to the number of modulation indexes. We propose an approximation which significantly reduces the number of signal pulses and which minimizes the mean-squared error for an arbitrary set of modulation indexes. We show that this approximation can have two objectives: 1) to reduce the number of pulses in the same manner as has been proposed for single-h schemes; and/or 2) to reduce the number of multi-h pulses; we also show the conditions where this latter objective is most practical. We compare this minimum mean-squared error approximation with another method which was recently proposed for CPM. We also give numerical results on detection performance which demonstrate the practicality of the proposed approximation.     

环氧树脂和石墨对高氯酸钾类烟火药撞击感度的影响

为了揭示高氯酸钾类烟火药的安全性,制备了本工作称为样品1#～7#的7种50/50/m/n-KClO4/Al/环氧树脂/石墨混合物体系(m=n=0;m=3,n=0;m=5,n=0;m=5,n=1;m=5,n=2;m=5,n=3;m=5,n=4)。用GJB772A-1997-601.1,热重-差热分析(TG-DTA)和扫描电子显微镜(SEM)研究了环氧树脂和石墨对高氯酸钾类烟火药撞击感度的影响。结果表明:样品1#～7#的撞击感度爆炸百分数分别为0,60,76,40,12,2和0。与样品1#比较,样品1#中加入环氧树脂使样品2#和3#的撞击感度爆炸百分数升高,且随样品1#中环氧树脂含量的增加,撞击感度爆炸百分数升高。与样品3#比较,样品3#中加入石墨使样品4#～7#的撞击感度爆炸百分数降低,且随样品3#中石墨含量的增加,撞击感度爆炸百分数以4#>5#>6#>7#次序降低。探讨了环氧树脂对KClO4/Al二元体系起增感作用和石墨起减感作用的原因。     

Editorial

On the start occasion of the New Year, 2010, we would like to extendour sincere appreciations and compliments to all readers, authors,reviewers, all the members of the editorial board of Optoelectronics     

基于TINI平台的嵌入式互联网接入技术研究

随着网络技术的发展,将各种设备接人互联网,利用互联网实现数据传输与远程监控成为当今电子设备发展的必然趋势.文中介绍了DS80OC400芯片以及基于此芯片的TINI系统.提出了采用TINI系统来实现非网络设备接入互联网的方法,包括硬件结构、软件设计以及开发流程等,并以RS-232接口为例,给出了此方法的具体实现.与传统的通过PC机转接的方法相比,此方法具有开发成本低、效率高、运行稳定、低功耗、体积小等特点.     

短脉冲非相参雷达的逆合成孔径成像及其稀疏恢复成像技术

短脉冲非相参雷达(NCSP)的辐射源输出微波脉冲持续时间短,针对于高速运动目标而言,其脉冲持续时间内的目标运动可忽略不计,对回波信号不需进行专门的脉冲内运动补偿。为了利用短脉冲非相参雷达信号进行逆合成孔径雷达成像,该文应用补偿相参处理的方法,去除辐射信号包络时间不确定性和初始相位的不确定性影响,在常规方法进行包络对齐和初相补偿后可利用距离-多普勒(RD)方法进行逆合成孔径雷达成像,仿真验证了补偿后信号成像的可行性。然而,短脉冲非相参雷达的载频随机抖动的因素会导致距离-多普勒成像结果在多普勒维度产生随机调制的旁瓣,影响成像的质量。利用稀疏恢复技术,在成像空间中对目标的散射中心进行稀疏重构,利用正交匹配追踪(OMP)算法和稀疏贝叶斯学习(SBL)算法进行成像,从而实现了抑制非相参因素引起的成像旁瓣,改进了成像质量,通过仿真验证了方法可行性。     

Organizational Media Affordances: Operationalization and Associations with Media Use

The concept of affordances has been increasingly applied to the study of information and communication technologies (ICTs) in organizational contexts. However, almost no research operationalizes affordances, limiting comparisons and programmatic research. This article briefly reviews conceptualizations and possibilities of affordances in general and for media, then introduces the concept of organizational media affordances as organizational resources. Analysis of survey data from a large Nordic media organization identified six reliable and valid organizational media affordances: pervasiveness, editability, self-presentation, searchability, visibility, and awareness. Eight media scales based on frequency of use of 10 media within each of three organization levels were differentially associated with these affordances. The conceptualization, measurement approach, and results from this study provide the foundation for considerable future organizational communication and ICT research.     

一种用于GPS信号快速捕获的自适应算法

采用聂孟-皮尔逊准则,以发现概率为性能指标,对基于FFT非相干累加的GPS信号捕获算法的性能进行了详细的理论推导,给出了该种方法的理论性能上界, 提出了一种用于快速捕获的高效自适应算法,并通过系统仿真对理论结果进行了验证.对实际情况中概率分布的合理近似使理论分析过程得以简化,并使判决门限可根据噪声方差及累加次数进行自适应调整的算法可以直接应用于实时GPS接收机的设计.     

Interference canceller for a single-wavelength bidirectional optical-fibre link

A simple and practical electronic technique is presented that provides interchannel-crosstalk isolation to better than a 10?9 BER for a 20 Mbit/s single-wavelength single-fibre full-duplex transmission system.