A tensile wearable SHF antenna with efficient communication in defense beacon technology

The study projects a flexible and compact wearable pear-shaped Super High Frequency(SHF)antenna that can provide detailed location recognition and tracking applicable to defense beacon technology.This mini aperture with electrical dimensions of 0.12λ_(0)×0.22λ_(0)×0.01λ_(0)attains a vast bandwidth over 3.1-34.5 GHz Super High Frequency(SHF)frequency band at S_(11)≤-10 dB,peak gain of 7.14 dBi and proportionately homogeneous radiation pattern.The fractional bandwidth(%BW)acquired is 168%that envelopes diversified frequency spectrum inclusive of X band specifically targeted to all kinds of defense and military operations.The proposed antenna can be worn on a soldier's uniform and hence the Specific Absorption Rate simulation is accomplished.The Peak SAR Value over 1 g of tissue is 1.48 W/kg and for 10 g of tissue is 0.27 W/kg well under the safety standards.The flexibility is proven by analyzing the full electromagnetic simulations for various bending conditions.Time response analysis is attained with its Fidelity Factor and Group Delay.Communication excellence is determined using Link Budget Analysis and it is seen that margin at 100 Mbps is 62 m and at 200 Mbps is 59 m.Prototype is fabricated along with experimental validation.All the results show harmony in shaping the antenna to provide critical situational awareness and data sharing capabilities required in defense beacon technology for location identification.

隧洞施工人员U-Beacon定位系统设计与开发

针对传统UWB定位技术在大范围隧洞内人员定位中存在布线成本高、施工周期长、风险高的问题,结合UWB定位技术和Beacon技术,提出一种基于U-Beacon的隧洞内人员定位系统,并针对隧洞复杂施工场景进行定位系统网络拓扑结构设计、U-Beacon定位系统部署方案设计及硬件电路设计。以施工人员佩戴便携式胸卡标签方式,提高系统易用性。采用TOA定位算法和Sage-husa自适应卡尔曼滤波算法对UWB测距数据进行定位和降噪处理,实现对洞室复杂施工环境的精准定位。实验结果表明,基于U-Beacon的人员定位系统大大降低施工成本,降低施工风险,同时Sage-husa自适应滤波算法在提高隧洞内定位精度和鲁棒性方面有很大的提升。

Beacon技术在智慧图书馆信息服务中的应用

Beacon技术的出现使得智慧图书馆个性化推送服务成为相关学者和专家研究的话题。为实现室内定位、用户行为分析以及信息推送等服务,研究借助Beacon技术搭建智慧图书馆Eddystone服务平台,该平台利用Eddystone-TLM优化质心定位算法提高定位准确性,并利用URL完成用户信息的推送。Eddystone-TLM改进质心定位算法后,待测点的实际位置和估算位置几乎相同,误差值为0。智慧图书馆Eddystone服务平台能完成室内准确定位、用户行为数据分析、信息推送。

Research on Signal of Field Monitor of 7220A Localizer Beacon Subsystem of ILS

From the actual perspective of working principle of localizer beacon subsystem of Instrument Landing System (ILS), consideration of the distance information from localizer antenna to field monitor antenna and wide aperture effect of localizer antenna, broke through the limitation of signals synthesized only far-field (FF), established the near-field (NF) model. The three-dimensional mathematical model of localizer beacon was designed, and the signals at both near-field and far-field were analyzed qualitatively. At the environment of Antenna Fault as well as Antenna Distribution Unit (ADU) phase shifter simulation, the characteristics of near-field and far-field were also compared. The simulation results showed that the model met the requirement of theory of localizer beacon, and the gap between two models was so evident, which resulted from the broken geometric symmetry in NF area. The model could provide valuable theoretical basis for performance evaluation and maintenance of the ILS, and meanwhile, provide reference for the further analysis of localizer beacon.

BeaLib: A Beacon Enabled Smart Library System

Nowadays, Global Positioning Systems (GPS) receivers are used for outdoor navigation, which are the part of recent smartphones and tablet devices. However, GPS is not suitable for indoor navigations due to its signal limitations which are blocked by ceiling and walls. Indoor navigation can be achieved through a mobile phone using a recent technology that utilizes Bluetooth, namely beacons. Beacons are small transmitters, run on Bluetooth Low Energy (BLE) technology, used as a point of reference for mobile devices and they can detect a Bluetooth enabled device once it enters its transmission range. In this paper, we present BeaLib: a beacon assisted indoor navigation technique for smart libraries. The proposed indoor navigation technique can also be used for other applications such as offices, retails, airports, hospitality, and education. For experimentation, beacons are placed in a library and a Bluetooth enabled smartphone is used to install a digital library application (App) which communicates with the beacons. The result shows that when the smartphone comes in the range of a beacon, it shows the information related to the book on the smartphone screen.

Safety Evaluation of Stop-Sign Mounted Beacons—A Cross-Sectional Study

Agencies in Iowa have utilized both overhead flashing beacons and stop-sign mounted beacons. Although several studies have shown that overhead flashing beacons are effective, some concerns have been raised about driver confusion. The main concern is that a driver may interpret a multiface flashing beacon with a red indication for their approach as an all-way stop control. As a result, the Iowa DOT has been advocating use of stop-sign mounted beacons rather than overhead flashing beacons. Since little information is available about this countermeasure, data for intersections with (treatment) and without (control) stop-sign mounted beacons were identified and a cross-sectional analysis conducted (due to few confirmable installation dates). Rural stop-controlled intersections with stop-sign mounted beacons in Iowa (USA) were identified (40 in total). Intersection characteristics such as number of approaches, intersection angle etc. were extracted. Additionally, characteristics of individual approaches such as roadway surface (gravel/paved), advanced stop-sign rumble strips, and advance signing were recorded. One or more control locations were manually selected for each treatment intersection based on matching roadway configuration, presence of lighting, advance stop line rumble strips, number of approaches, channelization, traffic volume, and proximity. Propensity scores were estimated to match 40 control locations for comparison. Negative binomial models for different injury combinations at nighttime and daytime were developed with an indicator variable for presence and absence of stop-sign mounted beacons. Presence of stop-sign mounted beacons was associated with a 5% - 54% reduction in nighttime crashes. Injury nighttime crashes decreased by 54% and total nighttime crashes reduced by 18%.

船用无线电标校信标机程控频点切换的设计

船用无线电标校信标机是指能够为船载统一测控设备提供稳定跟踪信号的射频信号发生器。一般安装于探空气球内部或悬挂于无人机底部,经过飞行至一定高度和距离后,船载统一测控设备对该信标信号进行跟踪试验。当前船用无线电标校信标机在空中仅能工作在一个频点,若需要对多个工作频点进行标校则需要重复释放多个无线电信标机。为解决此问题,设计一种标校信标机外围变频控制电路,将该电路连接至标校信标机即可完成释放一个信标机开展多频点标校的难题。该变频电路以低功耗单片机STC89C52RC作为基本控制单元,结合DC⁃DC降压模块和电平转换模块,实现将多个预置工作频点信息按预定帧格式定时发送至信标机的功能。经过十余次海上航天测量试验的检验,结果表明程控变频控制电路运行稳定、控制精度高,节省了标校时间和经费预算。

基于大数据聚类的飞行探测器复合跟踪控制系统设计

飞行探测器会受到气象条件、磁场等环境干扰,影响探测器的运动轨迹,进而影响跟踪精度;为实现对飞行探测器运动轨迹的实时跟踪与控制,设计基于大数据聚类的飞行探测器复合跟踪控制系统;在复合框架体系中,设置主控芯片、伺服驱动设备两类应用结构,并联合信标机元件,调节微惯性传感器器件的实时连接状态,完成飞行探测器复合跟踪控制系统的硬件设计;完善大数据聚类算法,根据跟踪路径节点标定结果,定义具体的复合跟踪坐标系,完成对飞行探测器复合跟踪的实时控制建模,结合相关硬件,实现基于大数据聚类的飞行探测器复合跟踪控制系统的设计;实验结果表明,所设计系统在跟踪1号、2号目标的跟踪准确率平均值分别为96.5%、97.0%,对目标跟踪时延的平均值为0.9 ms,可以保证基站主机对飞行探测器运动轨迹的实时控制能力。

基于iBeacon和多自由度MEMS的室内融合定位技术研究

由于GPS信号在室内环境下不能有效地实现定位和导航,因此精确的室内定位技术仍然是一个十分活跃的研究课题。行人航迹推算(PDR)可以使用智能手机的自带传感器实现室内连续定位。然而,它会随着行走距离的变长产生很大的累计误差。因此,提出一种基于iBeacon和手机MEMS相融合的精确的室内定位方法。在行走路径上加入iBeacon信标和二维码信标,系统自适应地选择相应的校正模式纠正PDR算法产生的累计误差。最后完成了基于Android平台的室内定位软件的开发。实验结果显示,文中方法的定位结果与PDR定位结果相比较,定位精度有了显著的提高,融合定位的平均误差在2m以内,定位精度满足项目需要。

Use of siRNA molecular beacons to detect and attenuate mycobacterial infection in macrophages

Tuberculosis is one of the leading infectious diseases plaguing mankind and is mediated by the facultative pathogen, Mycobacterium tuberculosis(MTB). Once the pathogen enters the body, it subverts the host immune defenses and thrives for extended periods of time within the host macrophages in the lung granulomas, a condition called latent tuberculosis(LTB). Persons with LTB are prone to reactivation of the disease when the body's immunity is compromised. Currently there are no reliable and effective diagnosis and treatment options for LTB, which necessitates new research in this area. The mycobacterial proteins and genes mediating the adaptive responses inside the macrophage is largely yet to be determined. Recently, it has been shown that the mce operon genes are critical for host cell invasion by the mycobacterium and for establishing a persistent infection in both in vitro and in mouse models of tuberculosis. The Yrb E and Mce proteins which are encoded by the MTB mce operons display high degrees of homology to the permeases and the surface binding protein of the ABC transports, respectively. Similarities in structure and cell surface location impute a role in cell invasion at cholesterol rich regions and immunomodulation. The mce4 operon is also thought to encode a cholesterol transport system that enables the mycobacterium to derive both energy and carbon from the host membrane lipids and possibly generating virulence mediating metabolites, thus enabling the bacteria in its long term survival within the granuloma. Various deletion mutation studies involving individual or whole mce operon genes have shown to be conferring varying degrees of attenuation of infectivity or at times hypervirulence to the host MTB, with the deletion of mce4 A operon gene conferring the greatest degree of attenuation of virulence. Antisense technology using synthetic si RNAs has been used in knocking down genes in bacteria and over the years this has evolvedinto a powerful tool for elucidating the roles of various genes mediating infectivity and survival in mycobacteria. Molecular beacons are a newer class of antisense RNA tagged with a fluorophore/quencher pair and their use for in vivo detection and knockdown of mR NA is rapidly gaining popularity.

Context-Aware Rate-Adaptive Beaconing for Efficient and Scalable Vehicular Safety Communication

Vehicular safety applications, such as cooperative collision warning systems, rely on beaconing to provide situational awareness that is needed to predict and therefore to avoid possible collisions. Beaconing is the continual exchange of vehicle motion-state information, such as position, speed, and heading, which enables each vehicle to track its neighboring vehicles in real time. This work presents a context-aware adaptive beaconing scheme that dynamically adapts the beaconing repetition rate based on an estimated channel load and the danger severity of the interactions among vehicles. The safety, efficiency, and scalability of the new scheme is evaluated by simulating vehicle collisions caused by inattentive drivers under various road traffic densities. Simulation results show that the new scheme is more efficient and scalable, and is able to improve safety better than the existing non-adaptive and adaptive rate schemes.

基于组合加权k近邻分类的无线传感网络节点复制攻击检测方法

无线传感网络节点体积小,隐蔽性强,节点复制攻击检测的难度较大,为此提出一种基于组合加权k近邻分类的无线传感网络节点复制攻击检测方法。通过信标节点的空间位置数据与相距跳数得出各节点之间的相似程度,结合高斯径向基核函数求解未知节点的横轴、纵轴的空间坐标,确定各网络节点的空间位置;根据网络节点的属性特征与投票机制建立节点复制攻击模型,凭借组合加权k近邻分类法划分节点类型,并将结果传送至簇头节点,由簇头节点做出最后的仲裁,识别出节点复制攻击行为。仿真结果表明,所提方法的节点复制攻击检测率最大值为99.5%,最小值为97.9%,对节点复制攻击检测的耗时为5.41 s,通信开销数据包数量最大值为209个,最小值为81个。

基于北斗/GPS双模的船舶通信航标遥测遥控系统

为解决船舶在复杂海况下信号不稳定问题,提升信息传输的安全性和抗干扰能力,获取准确、可靠的船舶位置信息,设计基于北斗/GPS双模的船舶通信航标遥测遥控系统。船舶通信航标终端利用北斗/GPS双模定位模块,解决船舶在复杂海况下信号不稳定问题,提升信息传输的安全性和抗干扰能力,获取准确、可靠的航标位置信息;利用温湿度传感器,采集航标附近环境信息,并通过北斗通信卡传输信息到终端管理中心;终端管理中心根据接收的信息,实时更新显示航标相关信息,并向船舶通信航标终端发送控制指令,确保船舶的航行安全和效率。实验证明,该系统可有效采集航标附近的环境信息,精准定位船舶位置;该系统可实现船舶通信航标的遥测遥控,确保船舶安全航行。

遥感卫星地面站12米口径天线Ka频段G/T值测试方法综述

Ka频段G/T值是遥感卫星地面站12米口径天线最重要的指标之一,其测试方法与遥感站目前常用的X频段测试方法相比,适用条件更加严苛,因此如何选取最佳的测试方法成为本文研究的主要内容。首先介绍了Ka频段12米口径天线特点;然后分别论述了分段测试法、信标法、比较法和射电源法的原理及其优缺点,并提出了Ka频段对月测试的这一最方便简洁的测试方法及其修正系数的研究方向;最后通过实测结果进行比较,给出Ka频段G/T值测试方法选取建议,为工程师现场测试提供了科学的指导和参考。

全球最大的iBeacon网络浮现

北京2015年12月18日电/--全球最大的i Beacon网络在中国浮现,整个网络由11万台beacon组成,这是目前已知的最大iBeacon网络,且由SENSORO进行建设以及运营;该网络已经覆盖：25家院线、16家机场、39个高端零售商场、40个大型景区、200所大学、260辆高铁、1500家必胜客餐厅、2100家周大福珠宝零售门店等等。

一种单信标测距辅助INS的导航方法

传统基于地球物理场的匹配辅助惯性导航方法在基础数据变化特征不明显或数据缺乏等苛刻条件下,难以实现有效匹配定位。为解决这一问题,提出了一种单信标测距辅助惯性导航系统(INS)的方法。首先,在单信标测距解析基准图上引入相关极值匹配辅助导航算法并进行重新建模。然后,采用差分进化寻优算法对该模型进行解算,并设计了一种固定匹配序列长度的建模方法以解决相关极值匹配算法实时性差的缺点。所提方法在缺乏地球物理基础数据条件下,仅需在海底布放单只声信标即可实现局部海域水下高精度实时定位。同时,由于采用的测距基准图为解析形式,所提方法也能较好地解决离散匹配算法定位精度受限于基准图分辨率等问题。最后,设计了相关实测实验,实验结果表明当惯导定位误差累积为1529.4 m时,采用所提方法与单信标匹配,定位误差减小为111.8 m,算法的有效性得到了验证。

奥曲肽修饰的壳聚糖纳米递送分子信标成像肺癌研究

目的 探究通过奥曲肽(OCT)修饰的壳聚糖(CS)miR-155分子信标(miR-155-MB)纳米(CS-miR-155-MB-OCT)识别miR-155并成像肺癌细胞用于肺癌早期诊断。方法 通过尾静脉注射A549肺癌细胞建立肺移植瘤裸鼠模型;通过鼻腔滴入Cre腺病毒,分别在滴入腺病毒后的4、6、8、12周处死小鼠建立LSL K-ras G12D转基因小鼠肺部的非典型增生、腺瘤、原位癌、肺腺癌的不同病变时期肺腺癌模型;取肺组织行HE染色观察。免疫组化染色检测肺移植瘤组织及不同病变时期转基因小鼠肺组织生长抑素受体2(SSTR2)的表达;实时荧光定量PCR检测不同病变时期转基因小鼠肺组织miR-155的表达。在肺移植瘤裸鼠模型中,尾静脉注射CS-miR-155-MB或CS-miR-155-MB-OCT;转基因小鼠模型中,尾静脉注射CS-miR-155-MB-OCT;活体成像仪检测肺移植瘤裸鼠及转基因小鼠不同病变时期肺部荧光信号;制作肺组织冰冻切片,激光共聚焦扫描显微镜(CLSM)检测荧光信号来源。结果 HE染色显示成功构建了肺移植瘤裸鼠模型及转基因小鼠肺部的非典型增生、腺瘤、原位癌、肺腺癌的不同病变时期肺癌模型。肺移植瘤及不同病变时期病变组织均表达SSTR2。转基因小鼠模型中,随着疾病进展,miR-155表达逐渐升高(P<0.05)。在肺移植瘤裸鼠模型中,CS-miR-155-MB-OCT组肺部荧光信号强于CS-miR-155-MB组(P<0.05);转基因小鼠模型中,随着肺癌的进展,荧光信号逐渐增强(P<0.05);将肺组织再次成像后发现荧光信号来自肺部,CLSM发现荧光信号来自肿瘤细胞及部分正常肺泡上皮细胞。结论 CS-miR-155-MB-OCT能够根据产生的荧光强度变化动态反映肺癌的发生发展,从而为肺癌的早期诊断提供新技术。

基于北斗短报文通信和组合模型算法的信标机设计

针对传统信标机落地后回收效率低、功率损耗大的问题,研制了一种可指示落点位置的新型信标机。在硬件部分,该信标机选用低功耗单片机STM32L431控制GPS定位模块和北斗短报文模块,并对供电电路实时采集。在软件部分,采用组合模型算法预测下一时刻的位置信息,并增加了“休眠工作”模式,实现与“正常工作”模式的循环切换。实验结果表明,组合预测结果和实地结果在经度、纬度和高度方向上的差值均在±25 m内,即落点搜寻工作可在以组合预测落点坐标为中心,维度为25 m×25 m×3 m的空间体内开展,提高了回收效率;双模切换的工作方式将能量损耗降低至传统信标机的64.7%,续航时间延长了11.16 h,具有较高的应用价值。

Pilot Beacon在CDMA双载频间切换的应用

本文论述了CDMA网络双载频间切换的几种方法,并就Pifot Beacon技术实现CDMA系统中双载频向切换的方式进行了相关实验和分析。

基于微信小程序和Beacon蓝牙的学生打卡系统设计

文章针对学生运动打卡系统的问题,设计了一种基于微信小程序和Beacon蓝牙技术的打卡系统。该系统通过使用Beacon蓝牙技术进行定位,可以在运动场地范围内自动完成打卡,实现快速便捷的运动打卡功能。通过对该系统进行实验和评估,发现其具有较好的可行性和实用性。该系统可以为学生提供更好的运动体验,同时为学校管理和教学提供更好的数据支持和管理手段。