基于双时间点检测的毫米波雷达人流量监测方法

针对现有基于视频监控的人流量统计方案成本高、算法复杂且不利于个人隐私保护的局限性，利用毫米波雷达体积小、成本低、分辨率高的特点，提出了一种基于双时间点检测的人流量监测方法。该方法先获取人体目标散射点位置和多普勒频移信息来构成点云数据，然后根据多普勒频移正负来判断人体的运动方向，并筛选具有高多普勒频移值的点云数据以降低干扰点对聚类结果的影响；在双时间点对特定区域内人员数量进行统计，并根据双时间点之间所获取的点云数据聚类结果对所统计人员数据进行修正。实验结果表明，该方法能够用匿名的方式以较高的正确率统计人员进出。     

Effects of displays on a direct reaching task: A comparative study of head mounted display and stereoscopic widescreen display

This study was conducted to investigate the virtual display effects on direct interaction performance metrics such as accuracy, task completion time, and comfort. Eighteen participants performed tapping (pointing) tasks in the coronal plane by directly reaching for tapping targets at three egocentric distance levels, with three indices of difficulty at each egocentric distance. The position data and severity of cybersickness symptoms were collected with a motion system and a symptom questionnaire, respectively. The results indicated that accuracy was higher with the stereoscopic widescreen display than with the head mounted display. However, no significant differences in task completion time, throughput, and cybersickness were observed between the two VR displays. In addition, increasing the egocentric distance improved accuracy and lengthened the task completion time, whereas increasing the task difficulty lengthened the task completion time but did not affect the accuracy. The findings are important and informative for users in choosing between the two virtual reality displays. Generally, the stereoscopic widescreen display can be recommended for tasks requiring high egocentric distance accuracy in the coronal plane. Furthermore, developers may refer to these findings in designing interfaces that allow a more natural way of interaction for users.     

Genetically Encoded Libraries of Constrained Peptides

Many therapeutic peptides can still be improved with respect to target specificity, target affinity, resistance to peptidases/proteases, physical stability, and capacity to pass through membranes required for oral delivery. Several modifications can improve the peptides’ properties, in particular those that impose (a) conformational constraint(s). Screening of constrained peptides and the identification of hits is greatly facilitated by the generation of genetically encoded libraries. Recent breakthrough bacterial, phage, and yeast display screening systems of ribosomally synthesized post-translationally constrained peptides, particularly those of lanthipeptides, are earning special attention. Here we provide an overview of display systems for constrained, genetically encoded peptides and indicate prospects of constrained peptide-displaying phage and bacterial systems as such in vivo.     

机载光电雷达它机试飞技术研究

机载光电雷达受平台及大气环境影响较大,而它机试飞能有效规避研制风险,是产品研制的必经阶段。本文介绍了机载光电雷达它机试飞试验系统组成、试验流程和数据处理等内容。经工程验证,实施过程满足任务需求,对其他光电系统的它机及本机试飞具有参考价值。     

基于分支定界法的相控阵雷达事件调度算法

为解决相控阵雷达事件调度问题中调度成功率、时间偏移率与算法时效性三者之间的矛盾，本文提出一种基于分支定界法的调度算法；该算法首先在现有调度结果上调取所有可执行事件，即获得若干"节点"，多步递推后由多"层"节点形成若干条备选"分支"，扩大解空间范围，提高算法性能；然后通过"删减"操作删减掉收益较低分支，将解空间控制在一适当范围内，减小搜索盲目性，降低算法计算量.仿真实验表明，与基于综合优先级算法的调度结果相比，利用本文算法调度时调度成功率提升了52%；与基于时间指针算法的调度结果相比，本身算法时间偏移率降低了61%；与基于遗传算法的调度结果相比，本文算法调度耗时仅为前者1~2%.     

基于改进飞蛾扑火优化算法的MIMO雷达相位编码信号集设计

提出一种MIMO雷达相位编码信号集设计方法，该方法对飞蛾扑火优化算法进行改进，利用改进的飞蛾扑火算法优化相位编码信号集，提高其正交性.在改进方法中，增加对火焰的更新过程，使火焰不仅能够保存最优飞蛾位置还具有搜索最优解的功能.优化过程以自相关函数旁瓣峰值和、互相关函数峰值和，以及自相关函数旁瓣能量、互相关函数能量作为算法适应度函数.仿真实验结果表明，改进方法明显提高了飞蛾扑火优化算法的收敛速度和收敛精度，且优化得到的信号集具有较低的自相关旁瓣值和互相关值.     

恒湿文物展柜用吸附式空气取水方法

博物馆恒湿文物展柜的湿度控制至关重要，为实现展柜的自动恒湿功能，本文基于吸附式空气取水原理，提出了一种将环境水汽自动补充至恒湿文物展柜系统水箱的方法，并搭建了相应的小型空气取水装置，证明了该方法的可行性；同时，构建了传热传质耦合的空气取水装置数学模型，在获取环境温湿度对装置取水量的影响规律后，分析加热功率和吸附床结构对装置单位能耗取水量的影响；此外，为便于装置的后期推广应用，提出了两个基于吸附床高度和直径的量纲为1参数。结果表明：进口空气的温度对取水量影响较小，但进口空气的湿度对取水量影响较明显，取水量随着湿度增加而增加；加热功率存在最优值，单位能耗取水量随着加热功率先增大后减小；在当前几何参数组合下，两个量纲为1参数η=2、β=4时，装置的单位能耗取水量最高。     

热仿真技术在加固显示器热设计中的应用

根据某型加固显示器的应用环境及内部功能模块的热特性,选择强迫风冷的散热方式,并通过热仿真计算指导风扇选型,根据仿真结果验证散热方案的可行性。最终,依据试验结果验证仿真结果的准确性,为加固显示器的热设计提供思路。     

雷达发射机浮动板调制器与故障检测电路的设计

提出了一种改进的浮动板调制器和对正负偏电压的故障检测电路,利用MOSFET寄生电容特性,通过固定脉宽窄脉冲控制调制脉宽,通过增加负偏MOSFET提高输出负偏电压。对故障检测电路进行仿真实验,通过模拟故障,验证故障检测报警信号发生时间均在微秒级别。完成样机的搭建,利用多重方式解决高压绝缘问题,并对其加电进行试验验证,分析实验波形,证明此电路满足设计要求并且具有可行性。     

Land surface deformation parameter estimation using persistent scatterer interferometry approach in an underground metal mining environment

Persistent scatterer interferometry (PSI) is a major advancement in radar interferometry for detecting and monitoring land deformation. PSI is the most advanced class of differential interferometric synthetic aperture radar (DInSAR) techniques. The technique conquers the main drawbacks of the conventional DInSAR technique by identifying radar targets having stable backscattering characteristics in time. These targets are termed as persistent scatterers (PSs). The higher the number of PSs for a study area the higher the accuracy of the results will be, which is most common for deformation analysis in urban areas. However, for non-urban or highly de-correlated areas, PSs density collapses significantly, which needs to increase for optimal results. For this purpose, partially coherent/distributed scatterers (DSs) are being exploited in addition to the PSs. The field surface of this study is one of the copper-rich mining belts in India, which consists of two major underground metal mines. Scatterer characterziation of the field surface under study suggests that most of the scatterers are DSs and very few scatterers under the influence of the mining zone are PSs. In addition to this, a preliminary investigation of deformation characteristics of the field surface under study reveals that the spatial extent of deformation is small/localized along with slow and non-linear deformation. Keeping in view scatterer and deformation characteristics of the field surface under study, in this research paper, a Quasi-Persistent Scatterer based PSI approach has been applied using high-resolution TerraSAR-X interferometric data stack (10 images) to generate deformation time series and deformation velocity. Furthermore, results obtained from the applied PSI approach and ground-based observations (using GNSS) have shown good agreement with each other, in the order of ?5.20?mm/year (LOS) and ?5.38?mm/year (subsiding), respectively.