An operational radar current observing and data service platform in the East China Sea

An ocean state monitor and analysis radar（OSMAR）, developed by Wuhan University in China, have been mounted at six stations along the coasts of East China Sea（ECS） to measure velocities（currents, waves and winds） at the sea surface. Radar-observed surface current is taken as an example to illustrate the operational high-frequency（HF） radar observing and data service platform（OP）, presenting an operational flow from data observing, transmitting, processing, visualizing, to end-user service. Three layers（systems）： radar observing system（ROS）, data service system（DSS） and visualization service system（VSS）, as well as the data flow within the platform are introduced. Surface velocities observed at stations are synthesized at the radar data receiving and preprocessing center of the ROS, and transmitted to the DSS, in which the data processing and quality control（QC） are conducted. Users are allowed to browse the processed data on the portal of the DSS, and access to those data files. The VSS aims to better show the data products by displaying the information on a visual globe. By utilizing the OP, the surface currents in East China Sea are monitored, and hourly and seasonal variabilities of them are investigated.

Current Climate Data Rescue Activities in Australia

1. Introduction Recovering historical instrumental climate data is crucial for identifying long-term climate variability and change, putting present climate into context and constraining future climate projections （Brunet and Jones, 2011）. In other words, to understand the future, we need to improve our understanding of the past.

Development of data acquisition and over-current protection systems for a suppressor-grid current with a neutral-beam ion source

Neutral beam injection is one of the effective auxiliary heating methods in magnetic-confinementfusion experiments. In order to acquire the suppressor-grid current signal and avoid the grid being damaged by overheating, a data acquisition and over-current protection system based on the PXI（PCI e Xtensions for Instrumentation） platform has been developed. The system consists of a current sensor, data acquisition module and over-current protection module. In the data acquisition module,the acquired data of one shot will be transferred in isolation and saved in a data-storage server in a txt file. It can also be recalled using NBWave for future analysis. The over-current protection module contains two modes： remote and local. This gives it the function of setting a threshold voltage remotely and locally, and the forbidden time of over-current protection also can be set by a host PC in remote mode. Experimental results demonstrate that the data acquisition and overcurrent protection system has the advantages of setting forbidden time and isolation transmission.

油气管道数据集成及可视化发展现状分析

通过调研国内外油气田智能化探索过程中管道数据集成及可视化的发展现状,分析了国内油气管道数据集成及可视化面临的挑战。基于挑战和智能化管道建设需求,从发展趋势和管道业务2方面提出管道数据集成及可视化未来研究方向。发展趋势重点关注管道数据系统、业务流与工作流的一体化以及生产管理的远程、实时化等方面的建设,管道业务则从感知领域、预测领域、管控领域以及优化领域等方面开展数据集成及可视化研究工作。

Analysis of sea surface height variabilities in the Kuroshio Current region by using Geosat altimeter data

The Geosat altimeter ERM T2-GDRs data were used to analyze sea surface height (SSH) variabilities in the Northwest Pacific region of 10°- 45°N, 120°-- 160°E covering all the Kuroshio Current. After processing the Geosat GDRs data, the 50 gridded SSH anomaly fields were acquired. The comparison between the SSH anomalies and tidal gauge sea levels showed that the altimeter data accorded with the tidal gauge data especially in the low frequency scale and in open sea. The mesoscale variability energy distribution obtained from the SSH anomalies was controlled by the position of the Kuroshio, bottom topography and the stationary meander of the Kuroshio. The relative transports of the Kuroshio Extension and the Kuroshio south of Japan, represented by the difference between the SSH anomalies on two sides of the current, had strong interannual and seasonal cycles, which was related to the Kuroshio large meander. When the Kuroshio meander occurred, the transport of the Kuroshio east of the Tokara Strait decreased, but that northeast of Taiwan Island increased. The variability of the transport east of the Philippines reflected the effects of the ENSO. The EOF analysis of the SSH anomaly fields showed that the first three EOFs accounted for 25.3%, 17.1 % and 13.7% of the total variance, and represented the meander mode, the ENSO mode and season mode respectively.

Statewide GNSS-RTN Systems: Current Practices

The applications of geospatial technologies and positioning data embrace every sphere of modern-day science and industry. With technological advancement, the demands for highly accurate positioning services in real-time led to the development of the Global Navigation Satellite System—Real-Time Network (GNSS-RTN). While there is numerous published information on the technical aspects of the GNSS-RTN technology, information on the best practices or guidelines in building, operating, and managing the GNSS-RTN networks is lacking in practice. To better understand the current practice in establishing and operating the GNSS-RTN systems, an online questionnaire survey was sent to the GNSS-RTN system owners/operators across the U.S. Additionally, a thorough review of available literature on business models and interviews with representatives of two major manufacturers/vendors of GNSS-RTN products and services were conducted. Study results revealed a great deal of inconsistency in current practices among states in the way the GNSS-RTN systems are built, operated, and managed. Aspects of the diversity in state practices involved the business models for the GNSS-RTN systems besides the technical attributes of the network and system products. The information gathered in this study is important in helping state agencies make informed decisions as they build, expand or manage their own GNSS-RTN systems.

面向海流反演的多普勒散射计天线转速优化方法

本文针对多普勒散射计天线转速过快或者过慢导致海流反演精度较低甚至无法进行海流反演的问题,提出了一种面向海流反演的天线转速优化方法。该方法以研究区域内被天线波束覆盖3次或者4次的目标海面数量为目标函数,以顺轨与交轨方向的波束足印连续性、空间分辨率要求作为约束条件,结合天线转速与天线扫描损耗的关系,建立了非线性约束下的多普勒散射计天线转速优化模型,利用优化得到的天线转速计算得到每个目标海面的观测方位向组合。利用海洋表面流实时分析数据,采用基于观测方位向优选的矢量流合成方法进行了海流反演实验。结果表明,在天线转速为20 r·min^(-1)时,不同研究区域内被雷达内、外波束足印覆盖到3次或者4次的目标海面数量占总目标海面数量的80%以上,反演得到的流速、流向标准差小于0.1 m·s^(-1)、20°,满足海洋工程应用对海流观测的精度需求。

电磁超声与电涡流复合线圈的数据融合及分析

以Q235钢板为研究对象,搭建了带有磁屏蔽结构的、共用螺旋线圈的、分时复用的、二维电磁超声与远场涡流复合仿真模型,分析了电磁超声对近表面缺陷检测的盲区,并从永磁体参数、接收线圈参数对复合远场涡流模型进行优化。针对Q235钢板(5~15)mm电磁超声与远场电涡流共同作用的区域,将电磁超声得到的幅值信号和时间信号,远场涡流得到的线圈感应电压和阻抗参数,利用灰狼优化算法的支持向量机进行数据融合,反演出缺陷的参数,并设计实验验证了仿真模型的准确性。研究表明:所设计的电磁超声与远场复合线圈对缺陷检测的准确率达到百分之96.14%,远场涡流能够很好地弥补电磁超声的检测盲区。

机械加工质量预测研究现状与发展趋势

机械加工质量预测是智能制造的重要组成内容,也是实现质量闭环控制的前提条件,对推动智能制造系统真正落地应用具有极其重要的作用.在对机械加工质量预测的历史进行简要回顾时发现,学者多将研究重点放在机床某一关键部件对加工质量影响的机理研究,却鲜见部件耦合影响的关联性研究.基于上述难题,本文首先剖析影响机械加工质量的7类要素,包括刀具几何参数、切削参数、切削液类型、热误差与热变形、数控机床零部件性能退化、切削颤振以及系统特性;随后,根据各要素数据种类和测量方式的不同,将机械加工质量监测与预测方法划分为4大类,包括机器视觉测量、功率测量、振动测量以及其他测量方法,并对各方法的技术特点、局限性和发展动态进行了阐述;最后,考虑各机械加工质量监测与预测方法的不足,指出材料切削机制研究、数据质量评估方法、面向工业现场数据库构建的标准以及质量预测信息的智能表征与可视化等方面可能是未来的发展趋势.

图书馆数据素养服务:基础、内涵与现状探究

数据素养服务是大数据时代对信息素养服务的延伸和细化,是对用户的数据意识、数据能力、数据利用等方面提出的更高要求。利用文献调研法系统综述了图书馆数据素养服务的相关研究,形成如下结论:在基础研究上,分为服务模式和服务行为研究,从中挖掘出服务对象精准化、能力培育多元化、能力指标体系化三点内涵,再归纳出数据素养教育、数据管理服务、数据素养服务平台三方面的服务现状研究。为数据素养服务研究提供框架和思路,推动图书馆科学数据管理与服务深入发展。

电力电缆温升特性研究及载流量计算

电力电缆通常敷设于地下,一旦发生故障,很难及时发现和维修。通过对电力电缆的温升特性研究和载流量计算可以有效减少电缆故障的发生。结合仿真试验、最优化算法以及对试验数据的归纳完成温度场分析和载流量计算。为确保有限元计算的准确性,使用最优化算法对模型进行校正。将校正后的有限元模型输入外界条件和电力电缆导体长期发热最高允许温度,通过迭代计算的方式得到电缆载流量。通过分析仿真试验的数据,总结出了电力电缆载流量与外界环境之间的函数关系,通过该函数关系可以快速估算电力电缆的动态载流量。经过温度场和载流量的计算,得到电力电缆电流的阈值,达到兼顾电缆安全可靠性和充分利用电缆传输能力的目的。

基于改进k-means算法的科研仪器机时智能计算系统

传统的机时统计常使用人工,不仅效率低,而且成本相对较大,因此在传统的机时计算的基础上提出一种基于改进k均值聚类算法的科研仪器机时智能计算系统。通过对仪器机时电流数据的聚类分析,完成对仪器机时的计算和统计,同时将传统k均值聚类算法进行改进,提升其系统机时计算的准确性。结果表明,使用改进k均值聚类算法后的机时系统在仪器的机时计算中表现更为优异,计算的时间与正常运行时间相同,能够在一定程度上达到0误差标准。由此可见,使用改进聚类算法进行仪器的机时统计能够提升机时计算结果的准确性。

采用模块化阵列的涡流探伤检测

针对工业领域的金属无损探伤中常常存在一些复杂部位,难以采用常规检测手段进行检测的问题,提出了一种优化探头结构的方法。将模块化理念引入涡流探伤中,设计并开发了一种模块化的涡流探伤系统。该涡流探伤系统将现有的互感式探头结构与电桥式探头结构相结合,结合2种结构各自的优势,以探头线圈上的感应电压值为缺陷检测的特征量,通过单片机将数据传输至以LabVIEW软件搭建的上位机并进行特征显示。测试结果表明,该系统能够检测到缺陷位置产生的感应电压值与无缺陷位置感应电压值的不同,验证了该设计的可行性,能够对金属表面缺陷进行高灵敏度的检测,实现了有效地判断金属材料缺陷位置的目的。

基于BP神经网络的配电网故障定位方法研究

配电网作为接入用户前的最后一道环节,其安全稳定运行直接影响着对用户的供电可靠性,因此配电网故障定位是一项重要的工作,值得深入研究。研究了基于BP神经网络的配电网故障定位模型,对BP神经网络的输入层、输出层和隐含层进行了设计。最后通过简单配电网系统数据对本文方法进行有效性验证。

机理-数据融合驱动的互联变流系统故障诊断方法

三电平中点钳位型互联变流器,因其大容量、高电能质量等优势,已逐渐成为交直流混联配电网系统的主流能量变换装备。但其长期工作于大功率、时变负载、有限散热等恶劣工况,功率器件开路故障率高。同时,现有故障诊断方法多为单一机理或数据依赖,无法克服系统模型结构复杂、运行工况多变的难题,诊断准确性与快速性较差。为此,提出了一种机理-数据融合驱动的互联变流系统故障诊断方法。首先,基于三电平变流系统的机理模型,结合神经网络观测器,构建机理-数据融合模型以提高故障诊断精度。随后,分析了电流残差量在不同器件开路故障后的变化轨迹,总结出电流残差故障特征表进行开路故障诊断。最后,实验与硬件在环测试结果验证了所提方法的有效性。

Variations in tidal currents and suspended sediment concentration of the upper part of the North Channel of Changjiang Estuary over the past 10 years

The tidal current duration （TCD） and velocity （TCV） and suspended sediment concentration （SSC） were measured in the dry season in December, 2011 and in the flood season in June, 2012 at the upper part of the North Channel of Changjiang Estuary. They were assimilated with the measured data in 2003, 2004, 2006 and 2007, using the tidal range＇s proportion conversion. Variations in TCD and TCV, preferential flow and SSC have been calculated. Influences of typical engineering projects such as Qingcaosha fresh water reservoir, Yangtze River Bridge, and land reclamation on the ebb and flood TCD, TCV and SSC in the North Channel for the last 10 years are discussed. The results show that： （1） currently, in the upper part of North Channel, the ebb tide dominates; after the construction of the typical projects, ebb TCD and TCV tends to be larger and the vertical average ebb and flood SSC decrease during the flood season while SSC increases during the dry season; （2） changes in the vertical average TCV are mainly contributed by seasonal runoff variation during the flood season, which is larger in the flood season than that in the dry season; the controlling parameters of increasing ebb TCD and TCV are those large-scale engineering projects in the North Channel; variation in SSC may result mainly from the reduction of basin annual sediment loads, large-scale nearshore projects and so on.

基于数据挖掘探究经皮经颅电刺激治疗卒中后运动障碍刺激参数应用规律

目的 基于数据挖掘探究经皮穴位电刺激(TEAS)及经颅直流电刺激(tDCS)治疗卒中后运动障碍的刺激参数应用规律。方法 检索中国知网、万方数据知识服务平台、维普资讯中文期刊服务平台、中国生物医学文献数据库、PubMed、Web of Science 2000年1月-2023年5月发表的相关临床研究文献,进行质量评价后建立数据库。采用频次分析、关联规则及复杂网络分析探究核心腧穴及电刺激参数应用规律。结果 共纳入文献79篇,提取128组数据。TEAS核心腧穴主要包括外关、手三里、足三里、合谷、内关、阳陵泉等,上下肢最常用配伍为手三里-外关、阳陵泉-足三里;电刺激参数中频率选择多样,100 Hz最常用,刺激弛缓型偏瘫上肢腧穴时亦多选用2 Hz;其他电刺激参数应用较一致,多选用脉宽200~250μs的双向对称方波,刺激强度以患者耐受为度。t DCS刺激电极多置于脑部M1运动区在头皮的投影,安全刺激强度为1~2 mA。结论 采用TEAS治疗卒中后运动障碍应根据卒中后不同康复阶段患者肌肉状态选择刺激腧穴及电刺激参数,尤需关注刺激频率的选择。

基于多源数据交互的高渗透率主动配电网保护策略

主动配电网中分布式电源渗透率逐步提高情况下,由于传统过电流保护的整定值预先设定,使得灵敏度降低,保护配合出现困难。为此,首先分析故障下不同类型分布式电源控制策略特点,并研究分布式电源出力、控制方式、并网点电压与故障电流之间的关系;然后,根据故障电流与电压的关系,在对主动配电网运行信息的多源数据融合方式进行研究后,提出在线自适应整定的电流保护策略;对分布式电源并网点增多且渗透率进一步提高下,改进后保护的灵敏度降低问题,利用采集的电压信息、节点导纳信息进行故障电流匹配计算以实现故障区段搜寻,为识别并切除线路故障提供依据;最后,通过PSCAD/EMTDC仿真结合MATLAB编程验证方案的有效性。

近十年国内外经颅直流电刺激治疗脑卒中的文献可视化分析

目的:调查了解近10年国内外经颅直流电刺激治疗脑卒中领域相关研究现状、热点及趋势。方法:检索中国知网和Web of Science数据库中2013~2022年关于经颅直流电刺激治疗脑卒中的相关文献,用CiteSpace软件对文献的国家、机构、作者以及关键词等进行可视化分析。结果:(1)Web of Science数据库共纳入946篇文献,发文量总体呈上升趋势。发文量最多的国家、机构和作者依次为:美国、哈佛大学和Fregni Felipe教授,热点关键词是运动皮质、恢复、康复、瘫痪手等。近2年突现词有系统综述、吞咽功能、障碍、模型等。(2)中国知网数据库共纳入392篇文献,发文量最多的机构和作者依次为:首都医科大学宣武医院康复医学科和宋为群作者,热点关键词是失语、上肢功能、吞咽障碍和运动功能等,近2年的突现词为非侵入性脑刺激、上肢功能和脑电图等。结论:tDCS治疗脑卒中的中文文献总体发文量不高,发文机构分布不平衡且缺乏合作,今后应加强不同地区、不同机构间的合作,开展多中心、跨区域研究,应进行更深层次的作用机制研究。

基于在线海流数据的自然能驱动无人艇能源最优路径规划

为了有效地利用在线监测到的海流和风数据,减少能源消耗以提高自然能驱动无人艇的续航力,以“驭浪者”号自然能驱动无人艇为研究对象,提出一种基于在线海流数据的能源最优路径规划方法。通过“驭浪者”号实船试验得到的最小回转半径对粒子群算法进行改进,设计距离最优的路径规划算法。考虑到海流和风对“驭浪者”号能源消耗的影响,建立海流和风影响下能源消耗模型;在静态海流环境中,以能源最优为目标对粒子群算法进行改进,探索能源最优的路径规划算法。根据“驭浪者”号在线监测到的海流和风信息,得到随时间-空间变化的动态海流数据,对能源最优的路径规划算法进行优化,提出基于在线监测海流数据的能源最优路径规划算法。通过仿真试验,对比距离最优的路径规划算法和基于在线监测海流数据的能源最优路径规划算法在相同工况下能源消耗情况,验证所提出算法的可行性和有效性。