本文为弥补基于传感器方法的检测系统存在的不足,基于低辐射UWB雷达系统设计了一套室内人员边缘检测系统.本系统可对少数目标情况下(目标数≤2)的人员进行有效跟踪;人员数目估计精度(含错误±1)可达95％以上;日常活动识别分类精度可达86％.

针对学生学习"数字信号处理"课程时存在的概念理解难、实际应用能力弱等问题,提出基于问题探索与项目驱动相结合的实验教学方式.首先,发布实验小课题,包括雷达探测目标的工作原理模型建立仿真、快速傅里叶变换的应用、雷达信号处理中数字正交解调的设计与实现;其次,从数字信号处理基本理论的角度讲解课题内容对应的相关知识点,并让学生完成相关实验.该教学方式强调学生对雷达探测项目为中心任务下的数字信号处理理论和方法的理解与综合运用.

近年来,随着智能物联网应用的快速发展,雷达传感器由于具有保护隐私、全天候全天时工作、不受光线和遮挡影响等优点,在人体目标日常行为活动识别方面受到了学术界和产业界的极大重视.针对一种超低辐射的超宽带雷达(Impulse Radio Ultra-Wideband,IR-UWB),提出了一种室内人员日常活动(包含静止、坐下、走路、起立)分类方法.该方法首先利用目标检测方法检测出目标有效距离单元;其次,提出了基于平均多普勒频率、信息量和多普勒能量的3种微多普勒特征进行动静目标粗分类;最后,采用长短期记忆神经网络(Long Short-Term Memory,LSTM)对人体活动进行细分类.实验结果表明,人体活动细分类的平均准确率能达到92.52％.

论文设计出了一种多目立体视觉的三维激光扫描系统,该系统基于ZYNQ异构计算平台,通过对精密的升降台进行控制,使用四组环绕形状的双目相机来获取不同位置处的线激光光带图像,提取光带中心,进行图像匹配,利用视差原理计算出所有光带中心的坐标,并将四路光带中心的坐标转换为统一的世界坐标系,进行点云数据的融合,最后快速地获取物体的三维点云数据,提高了系统的扫描速度及集成度。通过实验结果证明,在快速获取物体三维点云数据的情况下且物体的扫描精度可以保证在1mm的范围内,验证了该系统的可行性。

数模结合的综合性实验对促进学生电路知识的融会贯通,培养学生的综合动手能力非常重要.本文提出了数模结合的综合性实验的设计原则,并以数控速你小风扇和数字温度计为例阐述了该原则在实验教学中的应用.

The research develops a comprehensive assessment system of economic benefit of construction industry. The economic benefit of construction industry all over the country is analyzed and evaluated by factor analysis and cluster analysis. The consequence shows that there are great differentiations in all aspects of economic development level of construction industry among areas. Based on the result of cluster analysis, four groups are divided. The characteristics of the first group are great dimension, high level of technique and high working efficiency. The second are small scale, high level of technique and high working efficiency. The third are general scale, general level of technique and working efficiency. The characteristics of the fourth group are great dimension, technique and low working efficiency. In order to offer the development of construction industry of these areas some reference, according to these characteristics, some suggestions to improve the economic benefit of construction industry are put forward.

The performance of normalized throughput in a hybrid WDMA-OCDMA system is studied. Effect of optical beat noise and dispersion on the normalized throughput is analyzed. The scheme of BCH channel coding is proposed to improve the performance of a hybrid WDMA-OCDMA system. Analysis result shows that the normalized throughput can be improved greatly when traffic load is medium. Furthermore, the maximum normalized throughput will increase for the BCH-coded hybrid WDMA-OCDMA system

The central reflecting wavelength of FBG would vary with environment temperature, which would cause wavelength mismatch between optical encoder and decoder, and would decrease the autocorrelation power. Under considering the multi-access interference, the effect of wavelength mismatch on the spectral efficiency of multi-wavelength optical code-division multiple-access (MW OCDMA) system was analyzed. Through changing the judge threshold, BER of MW OCDMA system could be decreased greatly, and spectral efficiency of MW OCDMA system was improved. Analysis results show that spectral efficiency of MW OCDMA is little degraded by less than 10°C temperature variation in LAN or access network.

The scheme of dispersion-compensated fiber (DCF) and non-cyclic one-coincidence sequence was proposed to improve the BER performance of fast frequency-hopping optical CDMA system (FFH OCDMA). Effect of dispersion for non-cyclic one-coincidence sequence employing DCF was studied, and BER performance of FFH OCDMA system was analyzed. Analysis result shows that this scheme can improve the BER performance, and thus enhance the system capacity of FFH OCDMA.

提出了一种分段式双通道高速数据采集系统的设计方案,对其中高速A/D、高速存储、智能控制以及接口译码等模块进行了介绍.该设计方案解决了高速实时信号与接口总线之间的速度兼容问题,单双踪采样频率可调,具有较好的工业应用价值.

The basic concepts, merits and hierarchical structure of the optical transmitting network are described in this paper. Techniques of optical packet switching, including MPAS, optical frame, optical burst switching, OCDMA, are discussed. The scheme of packet switching over OCDMA is presented.