Deep Sea AUV Navigation Using Multiple Acoustic Beacons

Navigation is a critical requirement for the operation of Autonomous Underwater Vehicles（AUVs）.To estimate the vehicle position,we present an algorithm using an extended Kalman filter（EKF） to integrate dead-reckoning position with acoustic ranges from multiple beacons pre-deployed in the operating environment.Owing to high latency,variable sound speed multipath transmissions and unreliability in acoustic measurements,outlier recognition techniques are proposed as well.The navigation algorithm has been tested by the recorded data of deep sea AUV during field operations in a variety of environments.Our results show the improved performance over prior techniques based on position computation.

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.

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%.

Evaluation of Driver Behavior in Response to Stop Sign Beacons

Crashes at rural intersections are frequently a result of failure to yield. As a result, agencies attempt to find countermeasures that encourage drivers to stop and yield appropriately. A number of countermeasures have been utilized to reduce crashes and improve intersection safety. However, some treatments have been shown to have mixed results, while for others only limited information about effectiveness is available. Because even low-cost treatments require some maintenance, it is important for agencies to have good information about the effectiveness of the various treatments before investments are made. Stop sign beacons are one such low-cost measure. This paper discusses results of research which evaluated stop sign beacons. Stop sign beacons were installed at 10 stop-controlled approaches in the US state of Iowa. The beacons were set to activate only when an approaching driver was traveling over a set speed threshold which was set based on whether a driver would be able to stop. Video data were collected before, at 1-month, and at 12-month after installation. Type of stop (i.e., rolling, no-stop), stop location in reference to the stop bar, and location of initial brake application were reduced from the video data. The percentage of drivers who began braking before or after 350 feet were compared. This threshold indicates the point at which drivers would need to engage in hard braking based on approach speed and stopping sight distance. At one month, 6 of the 9 intersections experienced an increase in the percentage of vehicles braking at 350 feet or before. At 12-month, drivers at more than half of the approaches were braking sooner than the before period. Results also indicate stopping behavior improved after installation of the beacons. Most of the approaches (70%) showed an increase in the percentage of drivers who came to a full stop at 1-month compared to the period before installation. At 12-month, 71% of approaches showed an increase in drivers who came to a complete stop. Similar results were found for stopping location. Around 80% of approaches experienced an increase in the percentage of vehicle that stopped at or before the stop bar at the 1-month period after installation and 86% of approaches had an increase at 12-month.

A Self-Adaptive Back-off Optimization Scheme Based on Beacons Probability Prediction for Vehicle Ad-Hoc Networks

In order to improve the broadcast reception rates of beacon messages in vehicle ad-hoc networks,a conclusion that the relationship between collision probability and minimum contention window size and the relationship between expiration probability and minimum window size was reached by building a Markov model. According to this conclusion, a back-off algorithm based on adjusting the size of minimum contention window called CEB is proposed, and this algorithm is on the basis of the differential size between the number of expiration beacons and preset threshold. Simulations were done to compare the performance of CEB with that of RBEB and BEB, and the results show that the performance of the new proposed algorithm is better than that of RBEB and BEB.

A Three-Dimensional Range-Free Localization Algorithm Based on Mobile Beacons for Wireless Sensor Networks

In wireless sensor networks （WSNs） the position information of individual nodes is a matter of vital importance because allows the implementation of necessary network functions such as routing, querying and other applications. The objective of this paper is to propose an algorithm of three-dimensional distributed range-free localization for WSNs, using a mobile beacon （MB） equipped with a rotary and tilting directional antenna. This algorithm, denominated as the three-dimensional azimuthally defined area localization algorithm （3D- ADAL）, is executed in each sensor node and is based only on the analysis of the information received from the MB, therefore is energy efficient and contributes to extend the lifetime of the sensor network. Additionally the proposed algorithm has the advantage of being simple and economical. The simulation results show that the proposed algorithm is a practical, effective and accurate method for a three-dimensional location of sensor nodes in a WSN.

An Internet of Things Platform with Google Eddystone Beacons

Consumer adoption of Internet of Things devices is increasing rapidly. About 66% of consumers mean to buy an associated home gadget by 2019. Beacon technology helps in providing actionable insights to businesses through visual heat maps generated by the consumers and these maps are further processed by machine learning algorithms. Google’s open source Eddystone beacon format released in 2015, mitigates the problem of high cost and provides an open source alternative for developers. The aim of the proposed work is to provide a low cost, reliable, flexible, scalable and open source alternative for small and medium scale enterprises. In the proposed work, an Internet of Things platform is configured and developed. The Raspberry Pi is configured as an Eddystone beacon through a NodeJs server. An android app is developed which is the front end of the platform and web services are deployed on the cloud.

BLE beacons for sample position estimation in a life science automation laboratory

Estimation of the sample position is essential for working process monitoring and management in the life science automation laboratory.Bluetooth low-energy(BLE)beacons have the advantages of low price,small size and low energy consumption,which make them a promising solution for sample position estimation in the automated laboratory.Several fingerprinting models have been proposed to achieve indoor localization with the received signal strength(RSS)data.However,most of the research depends on intensive beacon installation.Proximity estimation,which depends entirely on one beacon,is more suitable for sample position estimation in large automated laboratories.The complexity of the life science automation laboratory environment brings challenges to the traditional path loss model(PLM),which is a widely used radio wave propagation model-based proximity estimation method.In this paper,BLE sensing devices for sample position estimation are proposed.The BLE beacon-based proximity estimation is discussed in the framework of machine learning,in which the support vector regression(SVR)is utilized to model the nonlinear relationship between the RSS data and distance,and the Kalman filter is utilized to decrease the RSS data deviation.The experimental results over different environments indicate that the SVR outperforms the PLM significantly,and provides 1 m absolute errors for more than 95%of the testing samples.The Kalman filter brings benefits to stable distance predictions.Apart from proximity-based sample position estimation,the proposed framework turned out to be effective in position estimation between parallel workbenches and position estimation on an automated workstation.

Distributed localization using mobile beacons in wireless sensor networks

A new distributed node localization algorithm named mobile beacons-improved particle filter （MB-IPF） was proposed. In the algorithm, the mobile nodes equipped with globe position system （GPS） move around in the wireless sensor network （WSN） field based on the Gauss-Markov mobility model, and periodically broadcast the beacon messages Each unknown node estimates its location in a fully distributed mode based on the received mobile beacons. The localization algorithm is based on the IPF and several refinements, including the proposed weighted centroid algorithm, the residual resampling algorithm, and the markov chain monte carlo （MCMC） method etc., which were also introduced for performance improvement. The simulation results show that our proposed algorithm is efficient for most applications.

Graphene oxide and molecular beacons-based multiplexed DNA detection by synchronous fluorescence analysis

We have developed a multiplexed DNA detection method based on graphene oxide （GO） and molecular beacons （MBs） by synchronous fluorescence analysis, demonstrated it by an oligonucleotide sequence of wild-type HBV （T1） and a re- verse-transcription oligonucleotide sequence of the RNA fragment of HIV （T2） as a model system. In the absence of targets DNA, FAM-tagged free MB probes （PHBv） and ROX-tagged free MB probes （PHIv） are adsorbed on GO via π-π interactions between DNA nucleobases and nucleosides, and the π-rich GO brings the fluorophores of MB and GO into close proximity. And then, the fluorescence of fluorophores is quenched by GO. But in the presence of targets DNA, PHBV and PHW hybridize with their targets DNA resulting in the formation of double-stranded DNA （dsDNA）, causing the separation of PHBV and PHW from the surface of GO and the recovery of the fluorescence of fluorophores （FAM and ROX） simultaneously. The simultane- ous detection of T1 and T2 can be realized by measuring fluorescence signals of FAM and ROX, respectively. Under the op- timum conditions, the fluorescence intensities of two dyes all exhibit good linear dependence on their target DNA concentra- tion in the range of 5×10-11-5×10 9 M. The detection limit of T1 is 3×10-11 M （3σ）, and that of T2 is 2×10-11 M. Compared with other methods for DNA detection based on GO, the proposed method has some advantages including higher selectivity and shorter analytical time.

Mechanics of molecular beacons for mRNA detecting

Decoding genetic information is crucial for gene therapy and cancer diagnosis,which has attracted growing interest in the field of clinical medicine and life science.In this study,we conducted a comprehensive exploration to obtain the detection mechanism of molecular beacons from a mechanics point of view.The potential energy function of molecular beacon/target system is established firstly,based on which the profile of molecular beacons is solved by genetic algorithm optimization.The length of stem and the total energy are further calculated when the target is hybridized with loop and stem.The results show that the hybridization between target and stem is energetically favorable compared with that between target and loop,indicating a new detection strategy.These analyses may cast light on understanding the mechanism of molecular beacons detection,and further help to design novel molecular beacons with high resolution and quantification.

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.

Development and Application of Detection Methods for Capture and Transcription Elongation Rate of Bacterial Nascent RNA

Objective Detection and quantification of RNA synthesis in cells is a widely used technique for monitoring cell viability,health,and metabolic rate.After exposure to environmental stimuli,both the internal reference gene and target gene would be degraded.As a result,it is imperative to consider the accurate capture of nascent RNA and the detection of transcriptional levels of RNA following environmental stimulation.This study aims to create a Click Chemistry method that utilizes its property to capture nascent RNA from total RNA that was stimulated by the environment.Methods The new RNA was labeled with 5-ethyluridine(5-EU)instead of uracil,and the azido-biotin medium ligand was connected to the magnetic sphere using a combination of“Click Chemistry”and magnetic bead screening.Then the new RNA was captured and the transcription rate of 16S rRNA was detected by fluorescence molecular beacon(M.B.)and quantitative reverse transcription PCR(qRT-PCR).Results The bacterial nascent RNA captured by“Click Chemistry”screening can be used as a reverse transcription template to form cDNA.Combined with the fluorescent molecular beacon M.B.1,the synthesis rate of rRNA at 37℃is 1.2 times higher than that at 15℃.The 16S rRNA gene and cspI gene can be detected by fluorescent quantitative PCR,it was found that the measured relative gene expression changes were significantly enhanced at 25℃and 16℃when analyzed with nascent RNA rather than total RNA,enabling accurate detection of RNA transcription rates.Conclusion Compared to other article reported experimental methods that utilize screening magnetic columns,the technical scheme employed in this study is more suitable for bacteria,and the operation steps are simple and easy to implement,making it an effective RNA capture method for researchers.

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。

基于事件流和组件的CSCW通用开发平台

提出了一个基于事件流和组件的CSCW开发平台设计方案，并以此构建了Beacon 系统，它支持组件化的开发模式，以事件流处理为核心，全面覆盖了从网络通信、群组通信 、访问控制到并发控制等多个环节，并在对象交互模型、事件处理和并发控制策略方面有所 创新。通过在Beacon系统上开发了几个协同应用程序，验证了该平台具有很强的扩展性、通 用性、稳定性和开发灵活性。

Beacon技术在图书馆的应用探索

在互联网+背景下,文章通过研究Beacon技术在国内外应用的实例,结合图书馆情况,论述该技术在图书馆应用的可行性,提出基于该技术的活动消息推送、馆藏导航、阅读推广、感应借书、阅览室座位管理、阅读分享互动、活动签到等图书馆应用设想,创造全新的智慧服务体验。

面向城市环境VANETS的基于beacon控制的路由协议

车载网络(Vehicular ad hoc networks,VANETs)是一种特殊形式的网络,具有节点高速移动、拓扑频繁的变化的特性,这些特性为消息的传播带来挑战,路由机制是实现消息传递的关键因素;地理位置路由被广泛地应用于VANETS,要求节点周期广播beacon消息;然而,节点周期地广播beacon消息,降低了路由性能,特别是在城市区域,由于节点密集,每个节点均广播beacon消息,恶化了路由性能;为此,针对城市环境,提出基于beacon控制的路由协议RPBC(Routing protocol with beacon control);在RPBC中,并非每个节点广播beacon消息,而设置有效的机制选择部分节点广播,从而降低了beacon冗余,同时,采用最短路径算法,减少数据传输跳数;仿真结果表明,提出的RBPC在分组投递率、端到端传输时延以及路由开销方面均有较好的性能。

基于微信公众平台和iBeacon的智慧校园LBS应用设计

微信公众平台为开发者提供了一个通用的信息服务发布平台,通过约定的身份信息和接口标准,利用微信最新客户端和微信公众平台提供的对蓝牙BLE和i Beacon技术的支持接口,提出了一种通过微信公众平台和i Beacon基站及时获取用户当前位置和场景信息的方法,以LBS签到功能为例,给出了LBS应用实现方案和流程图,叙述了如何将用户信息、用户场景和智慧校园后台系统进行对接和联动的实施细节。

Fast Digital Correlation Calculation Method in Extended Beacon Wavefront Detection

On the basis of Hartmann Shack sensor imaging analysis, a new method is presented with which the wavefront slope can be obtained when the object is incoherent and extended. This method, which is demonstrated by both theoretical interpreting and computer simulation, explains how to measure the wavefront slope difference between two sub apertures through the determination of image displacements on detector plane. It includes a fast and accurate digital algorithm for detecting wavefront disturbance, which is much suitable for realization in such electrical hardwares as digital signal processors.

分众传媒的新媒体融合之路

移动互联网的蓬勃兴起正在颠覆传统媒体的传播模式,在"互联网+"的时代背景下,分众传媒控股有限公司选择借力i Beacon技术,积极谋划战略转型布局,打造中国最大的O2O媒体集团,实现自我进化的新媒体融合之路。本文以分众传媒为例,对其新媒体环境下面临的挑战以及与i Beacon技术的深度融合发展进行研究剖析,旨在思考站在"互联网+"风口的传媒业,如何实现以技术为要的新媒体融合之路。