Domain adaptive methods for device diversity in indoor localization

To solve the problem of variations in radio frequency characteristics among different devices,transfer learning is applied to transform device diversity to domain adaptation in the indoor localization algorithm.A robust indoor localization algorithm based on the aligned fingerprints and ensemble learning called correlation alignment for localization(CALoc)is proposed with low computational complexity.The second-order statistical properties of fingerprints in the offline and online phase are needed to be aligned.The real-time online calibration method mitigates the impact of device heterogeneity largely.Without any time-consuming deep learning retraining process,CALoc online only needs 0.11 s.The effectiveness and efficiency of CALoc are verified by realistic experiments.The results show that compared to the traditional algorithms,a significant performance gain is achieved and that it achieves better positioning accuracy with a 19%improvement.

Accuracy and Electromagnetic Safety Evaluation of a Portable Electromagnetic Localization System for Micro Invasive Medical Devices in Vivo

Aiming at localizing the telemetric capsule for detecting gastrointestinal physiological parameters in vivo accurately,a portable alternating current(AC)electromagnetic localization system is designed.To verify the feasibility of the method,the model and construction of the localization system are detailed.And static and dynamic accuracy of the localization system are tested by experiments.Next,we compare the simulating results of the electromagnetic radiation aroused by the localization system with the electromagnetic safety standards of human(ICNIRP guidelines and IEEE standard C95.1-1991).Finally,in terms of the results of the static and dynamic experiments,conclusions are drawn that the accuracy of portable positioning system is high(less than 10 mm)enough to satisfy the localization need of the micro invasive medical devices in vivo,and there is no harm of electromagnetic radiation to human.

Utility-Improved Key-Value Data Collection with Local Differential Privacy for Mobile Devices

The structure of key-value data is a typical data structure generated by mobile devices.The collection and analysis of the data from mobile devices are critical for service providers to improve service quality.Nevertheless,collecting raw data,which may contain various per⁃sonal information,would lead to serious personal privacy leaks.Local differential privacy(LDP)has been proposed to protect privacy on the device side so that the server cannot obtain the raw data.However,existing mechanisms assume that all keys are equally sensitive,which can⁃not produce high-precision statistical results.A utility-improved data collection framework with LDP for key-value formed mobile data is pro⁃posed to solve this issue.More specifically,we divide the key-value data into sensitive and non-sensitive parts and only provide an LDPequivalent privacy guarantee for sensitive keys and all values.We instantiate our framework by using a utility-improved key value-unary en⁃coding(UKV-UE)mechanism based on unary encoding,with which our framework can work effectively for a large key domain.We then vali⁃date our mechanism which provides better utility and is suitable for mobile devices by evaluating it in two real datasets.Finally,some pos⁃sible future research directions are envisioned.

A Finite Difference Scheme for a Semiconductor Device Problem on Grids with Local Refinement in Time and Space

The momentary state of a semiconductor device is described by a system of three nonlinear partial differential equations. A finite difference scheme for simulating transient behaviors of a semiconductor device on grids with local refinement in time and space is constructed and studied. Error analysis is presented and is illustrated by numerical examples.

An improved 3D shape haptic rendering algorithm for finger mounted vibrotactile device

To improve the sense of reality on perception, an improved algorithm of 3D shape haptic rendering is put forward based on a finger mounted vibrotactile device. The principle is that the interactive information and the shape information are conveyed to users when they touch virtual objects at mobile terminals by attaching the vibrotactile feedback on a fingertip. The extraction of shape characteristics, the interactive information and the mapping of shape in formation of vibration stimulation are key parts of the proposed algorithm to realize the real tactile rendering. The contact status of the interaction process, the height information and local gradient of the touch point are regarded as shape information and used to control the vibration intension, rhythm and distribution of the vibrators. With different contact status and shape information, the vibration pattern can be adjusted in time to imitate the outlines of virtual objects. Finally, the effectiveness of the algorithm is verified by shape perception experiments. The results show that the improved algorithm is effective for 3D shape haptic rendering.

Heat Transfer and Energy Utilization of Waste Heat Recovery Device with Different Internal Component

Steel industry is high energy-consuming industry, and its waste?heat recovery is critically?important for energy utilization. In this study, pipeline bundle is used to enhance heat transfer in?waste?heat recovery device,?and?associated gas-solid heat transfer and energy utilization performance with different pipeline arrangement, pipe diameter and shape of internal component are further analyzed. The temperatures of gas and particle in device with pipeline bundle periodically fluctuate in horizontal direction, and those in staggered system distribute more uniformly than those in paralleled system. Compared with paralleled device, exergy and waste heat utilization efficiency of staggered device have been improved, and they are both higher than?those without pipeline. As pipe diameter increases, exergy and waste heat utilization efficiency first increases and then decreases, and they reach the maxima with optimal pipe diameter.?As the width of internal component keeps constant, influence of its shape on heat transfer is very little.

A BLOCK-CENTERED UPWIND APPROXIMATION OF THE SEMICONDUCTOR DEVICE PROBLEM ON A DYNAMICALLY CHANGING MESH

The numerical simulation of a three-dimensional semiconductor device is a fundamental problem in information science. The mathematical model is defined by an initialboundary nonlinear system of four partial differential equations: an elliptic equation for electric potential, two convection-diffusion equations for electron concentration and hole concentration, and a heat conduction equation for temperature. The first equation is solved by the conservative block-centered method. The concentrations and temperature are computed by the block-centered upwind difference method on a changing mesh, where the block-centered method and upwind approximation are used to discretize the diffusion and convection, respectively. The computations on a changing mesh show very well the local special properties nearby the P-N junction. The upwind scheme is applied to approximate the convection, and numerical dispersion and nonphysical oscillation are avoided. The block-centered difference computes concentrations, temperature, and their adjoint vector functions simultaneously.The local conservation of mass, an important rule in the numerical simulation of a semiconductor device, is preserved during the computations. An optimal order convergence is obtained. Numerical examples are provided to show efficiency and application.

局部干法水下焊接装置的研制

为了对核燃料池进行水下焊接,研制了一套局部干法水下焊接装置。通过搭建试验平台,采用该装置在亚克力池中进行了水下非熔化极惰性气体保护电弧焊试验,利用圆形补丁片对不锈钢壁面上的缺陷部位进行焊接修复。结果表明,焊后焊缝成形良好,可以实现水下废池的修复,验证了该局部干法水下焊接装置的可行性。

局部干法水下激光焊接装置研制及工艺试验

针对核电站乏池边角位置的水下修复需求,研制了一套局部干法水下激光焊接装置,可在实现常规水下平焊位置焊接的同时,重点兼顾角焊缝的局部干法水下焊接作业需求。同时,该装置还具备水下焊接位置的照明、焊接环境和焊接过程的实时监控、焊接区域的温湿度监测等功能。采用研制的局部干法水下焊接装置,对核电站乏池常用的304不锈钢材料进行了水下焊接工艺试验,结果表明:水下焊接焊缝的成形良好,水下焊缝的宏观形貌、截面形貌和金相组织与空气环境成形焊缝无显著差异。

基于局域发射光谱的LEAD装置螺旋波等离子参数测量

发射光谱法是常见的用于诊断等离子体的光学诊断技术,然而,这项技术并不能在空间上分辨等离子体。为了以低成本得到高空间分辨率的等离子体参数,发展了局域发射光谱法。这是一种将光纤伸入等离子体中以采集光纤前端等离子体光谱学信息的高空间分辨率光学诊断技术。介绍了局域发射光谱法技术的原理,并在大型线性等离子体实验装置LEAD上用蚊香形射频天线激发了氩等离子体,并在不同的射频功率和径向位置下对比了局域发射光谱法测得的等离子体光强和朗缪尔探针测得的等离子体电子密度,同时观察到了在射频功率500 W左右等离子体从感性耦合放电模式到螺旋波模式的跳变。结果表明:局域发射光谱法测得的光强与实验室现有的朗缪尔探针测量的电子密度之间较强的正相关,证明了用光强表征电子密度的可靠性,和LEAD装置上现有的朗缪尔探针在不同的等离子体模式的诊断上互补。

Al纳米颗粒高频局域等离激元效应对BCzVBi深蓝光有机发光器件发光效率的影响

蓝紫光有机电致发光器件难以提升发光效率.本文以BCzVBi作为深蓝荧光材料,把Al纳米颗粒引入ITO/:PEDOT:PSS/TAPC/BCzVBi:BCPO/TmPyPb/Liq/Al有机发光器件的TmPyPb电子传输层,尝试用A1纳米颗粒的高频局域等离激元效应来改善此问题.在室温真空蒸镀Al膜,厚度为1 nm时,形成尺寸在10 nm量级的分散纳米颗粒.将这种颗粒膜插入TmPyPb层内距离BCzVBi:BCPO发光层x=4,8,12 nm处,与没有Al层的对比器件相比,器件的电流密度和发光亮度都会因载流子迁移率变差而下降.但在x=8 nm,两者都显著回升.其机理可能在于,x<8 nm,会产生过强的荧光淬灭,而x>8 nm,到达Al颗粒的荧光衰减过多,又难以产生足够强的局域等离子体振荡.在x=8 nm,达到最大亮度的电压(9 V)没有变化,最大亮度从4200 Cd/m^(2)降到3500 Cd/m^(2),但电流密度也从335.19 mA/cm^(2)减小到145.71 mA/cm^(2),使得电流效率反而从0.88 Cd/A提高到2.36 Cd/A,从而把外量子效率提升了170%,效率滚降比则从78%降到30.5%,压减61%.在电流密度高达270 mA/cm^(2)时,电流效率和外量子效率也能提升66.5%.这些结果表明,Al纳米颗粒高频局域表面等离激元确实能够有效增强深蓝光有机发光二极管的发光性能.

自张式膨胀管技术的研究与应用

孔内膨胀管钻探技术是保障复杂地层孔壁稳定的有效技术之一。本文针对易出现缩径、坍塌、掉块的强水敏性地层,提出了一种自张式膨胀管护壁方法,并根据该方法的护壁原理研制了相适配的新型扩孔钻具、膨胀管及膨胀管投送装置,在不改变钻孔结构的情况下,对复杂孔段进行局部扩孔,投送膨胀管借助自身张力自然弹开而固定在相应的扩孔段,实现钻进时护壁。通过室内及现场试验对机具进行了优化,最终取得了良好的应用效果。试验证明:该方法操作简单可靠、易于定位,相较于水泥浆护壁具有处理速度快、停待时间短、减少重复处理等优势,适用于岩心钻探领域多孔段复杂地层的固壁与护壁,有利于降低孔内事故处理的成本、提高钻进效率,具有较好的推广应用价值。

基于相位偏移的压缩感知无源多目标定位方法

无源定位作为一种新兴的定位技术,是安防监控、入侵检测和接触跟踪等被动传感领域的研究热点。其通过分析无源目标对无线链路的阴影效应来定位目标。相位是无线信号的一个重要特性,比信号强度更具细粒度。为提升定位性能,利用无线链路相位信息,提出基于相位偏移的压缩感知无源多目标定位方法。该方法将接收信号相位偏移值作为观测数据,结合变分贝叶斯推理,恢复目标位置稀疏向量。仿真实验结果表明,在6.5 m×6.5 m的监测区域中,基于接收信号强度的定位方法平均定位误差为0.579 0 m,而该方法的平均定位误差为0.254 7 m,定位精度提升超过1倍,且该方法具有较强的鲁棒性。

A Bionic Vibration Source Localization Device Inspired by the Hunting Localization Mechanism of Scorpions

The challenges we are faced with in localizing objects are the complex environments,such as tunnels,high-rise areas and underground parking lots.This paper develops a bionic vibration source localization device to estimate the direction of the object which is inspired by the unique and precise hunting localization mechanism of scorpions.The localization device uses the sensor array,which is patterned after the scorpions5 biological sensory structure,and imitates the coding mode of scorpions,sensory neurons for determination of the prey(vibration source)bearing.To verify the effectiveness of the localization device,some experiments were performed through real collected vibration signals.The Average Estimated Error(AEE)and the Relative Estimated Error(REE)of the experimental results were calculated to be 3.64°土2.44°and-1.43°±4.14°,respectively.It indicates that the device has a good performance to estimate the bearings of vibration sources at different distances and azimuths.This bionic localization device lays the foundation for the development of locating the moving object in some special conditions.

基于国产化平台的冲击波超压测试系统设计

在当前特种测试系统国产化替代趋势下,针对传统冲击波超压测试系统存在的安全性低、进口依赖性强和自主可控性差等技术问题,提出了一款以国产复杂可编程逻辑器件(Complex Programmable Logic Device,CPLD)和ARM(Advanced RISC Machine)处理器为核心架构的冲击波超压测试系统。其中,ARM单元负责响应系统工作循环指令,CPLD则控制A/D转换模块实现采样频率高达1 MHz的数据采集和对内外触发逻辑的精确判断,数据转换结果经由外部存储器控制器(External Memory Controller,EXMC)传输并存储至eMMC存储器中,最终通过以太网传输至上位机显示。经现场试验表明,测试系统具有良好的可靠性,能够在复杂测试环境下实现对冲击波超压信号高保真采集与记录存储,为动态数据采集提供了一种切实可行的解决方案,推动了关键测试设备国产化替换进程。

高压干式移磁无级调压软起动装置和就地无功补偿装置在制氧站的应用

以某铅冶炼厂制氧站改扩建项目为例,介绍高压干式移磁无级调压软起动装置和就地无功补偿装置的工作原理及其在罗茨鼓风机上的应用、高压干式移磁无级调压软起动装置和就地无功补偿装置的选型及参数计算、罗茨鼓风机配电系统设计、罗茨鼓风机现场运行效果。

联网医疗设备网络安全管理规范地方标准构建与实践路径

联网医疗设备的安全性是医疗质量的重要保证。针对联网医疗设备网络安全管理风险以及安全管理难点,苏州市卫生计生统计信息中心构建了基于联网医疗设备网络安全管理框架的地方标准,结合网络安全管理工作实践,指出应全方位落实网络安全监管机构、行业主管部门、联网医疗设备使用机构以及联网医疗设备厂商等多方职责,以确保医疗质量与患者安全。

分层模型与改进IA的含DG配电网故障定位研究

常规的含分布式发电(DG)装置的配电网故障定位方法忽略了配电网馈线节点数量的影响,导致定位结果精度不高。因此,将分层模型与改进免疫算法(IA)相结合,设计了分层模型与改进IA的含DG配电网故障定位方法。首先,构建三层含DG配电网故障分层模型,并分析单节点故障信息。然后,通过改进基础IA的抗体间相似度,优化算法的期望繁殖度。最后,基于改进后的IA优化分层模型的节点搜索路径,建立世界坐标系并融合DG开关状态得到最终的故障定位信息。试验结果表明:应用该方法定位的故障节点距离与真实的故障节点距离最大差值仅为0.013 km。该方法表现出的适应度值曲线与最优适应度值曲线高度接近,定位精度较高,能够满足含DG配电网故障运维工作的现实需求。

煤矿井下局部通风机风筒保护装置研究

在煤矿生产中,掘进巷道通风很重要,对矿井安全生产有直接的影响。为了确保巷道通风的稳定性,需要以延长通风机风筒的使用寿命为切入点,降低局部通风机风筒损坏率及漏风系数。通过分析,设计了1套风筒保护装置,并对新型风筒保护装置进行了性能分析。该装置的应用能明显降低风筒的损坏率,延长风筒使用寿命,解决了掘进巷道风量不足的问题,取得了显著应用成效。

水电站起重设备控制系统国产化运用研究

水电站作为国家重点战略能源基地,起重设备是水电站安全运营的关键设备,直接关系到水电站建设和运行的安全,国产化替换研究已经刻不容缓。该文介绍了水电站起重设备控制系统长期以来依赖国外技术的弊端,目前中国起重设备控制系统发展状况,国产化替换研究的目的和存在的风险,细致调研了起重设备国产化控制器件厂商,根据调研结果展开了择优选型和系统设计,通过负荷试验和可靠性能试验,验证了起重设备国产化替换方案的可行性。