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Algorithms of mining data records from website automatically
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作者 邱勇 兰永杰 《Journal of Southeast University(English Edition)》 EI CAS 2006年第3期423-425,共3页
In order to improve the accuracy and integrality of mining data records from the web, the concepts of isomorphic page and directory page and three algorithms are proposed. An isomorphic web page is a set of web pages ... In order to improve the accuracy and integrality of mining data records from the web, the concepts of isomorphic page and directory page and three algorithms are proposed. An isomorphic web page is a set of web pages that have uniform structure, only differing in main information. A web page which contains many links that link to isomorphic web pages is called a directory page. Algorithm 1 can find directory web pages in a web using adjacent links similar analysis method. It first sorts the link, and then counts the links in each directory. If the count is greater than a given valve then finds the similar sub-page links in the directory and gives the results. A function for an isomorphic web page judgment is also proposed. Algorithm 2 can mine data records from an isomorphic page using a noise information filter. It is based on the fact that the noise information is the same in two isomorphic pages, only the main information is different. Algorithm 3 can mine data records from an entire website using the technology of spider. The experiment shows that the proposed algorithms can mine data records more intactly than the existing algorithms. Mining data records from isomorphic pages is an efficient method. 展开更多
关键词 data mining data record WEBSITE isomorphic page
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Multi-parameter influence on deceleration performance of ejector system for emergency flight data recorders
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作者 Haozhe Mao Daren Zheng +2 位作者 Zhi Sun Guojian Zhu Hengyi Liu 《Aerospace Traffic and Safety》 2025年第2期97-104,共8页
In the event of an aircraft crash over the ocean,the potential risk of the Flight Data Recorder(FDR)system sinking to the ocean in conjunction with the aircraft debris is substantial,which would significantly complica... In the event of an aircraft crash over the ocean,the potential risk of the Flight Data Recorder(FDR)system sinking to the ocean in conjunction with the aircraft debris is substantial,which would significantly complicate search and rescue operations.To mitigate this challenge,a separable flight data recorder has been developed by our team which called Emergency Flight Data Recorder(EFDR)system.Encapsulated within a cushioning airbag,the recorder is ejected from the aircraft and decelerates to the sea surface via a deceleration parachute,enhancing both the efficiency of search and recovery operations and the feasibility of flight data analysis.This paper presents an experimental study on the ejection velocity of the ejection system in the EFDR framework,focusing on three critical parameters:airbag material,deceleration parachute placement,and flight data recorder weight.The experimental results indicate that encapsulating the device in an airbag reduces ejection velocity,with fabric airbags inducing a smaller velocity decrement compared to rubber counterparts.Additionally,the deployment of a deceleration parachute further decreases ejection velocity,with a more pronounced reduction observed when the parachute is positioned in front of the projectile than when placed at rear.However,this velocity penalty is deemed acceptable due to the enhanced reliability of parachute deployment in the anterior configuration.Within the counterweight weight range of 2–6 kg,ejection velocity exhibits a marginal decrease with increasing weight,suggesting that variable payloads have a negligible influence on ejection performance.These findings provide empirical insights for the subsequent design optimization of the EFDR system. 展开更多
关键词 Separated flight data recorder Aircraft safety and rescue Pneumatic ejection experiment Ejection velocity Airbag material PARACHUTE
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Design of universal data structure and interface based on dynamic self-incremental record
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作者 Yan Li Peng Ji 《International Journal of Technology Management》 2015年第3期115-116,共2页
In the software of data management system, there are some different lengths of records needed storing in an array, and the number of records often increases in use of the software. A universal data structure is presen... In the software of data management system, there are some different lengths of records needed storing in an array, and the number of records often increases in use of the software. A universal data structure is presented in the design, and it provide an unified interface for dynamic storage records in different length, so that the developers can call the unified interface directly for the data storage to simplify the design of data management system. 展开更多
关键词 data management system length-variable data record dynamic self-incremental array
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Detection of Turbulence Anomalies Using a Symbolic Classifier Algorithm in Airborne Quick Access Record(QAR)Data Analysis 被引量:1
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作者 Zibo ZHUANG Kunyun LIN +1 位作者 Hongying ZHANG Pak-Wai CHAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第7期1438-1449,共12页
As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The ... As the risks associated with air turbulence are intensified by climate change and the growth of the aviation industry,it has become imperative to monitor and mitigate these threats to ensure civil aviation safety.The eddy dissipation rate(EDR)has been established as the standard metric for quantifying turbulence in civil aviation.This study aims to explore a universally applicable symbolic classification approach based on genetic programming to detect turbulence anomalies using quick access recorder(QAR)data.The detection of atmospheric turbulence is approached as an anomaly detection problem.Comparative evaluations demonstrate that this approach performs on par with direct EDR calculation methods in identifying turbulence events.Moreover,comparisons with alternative machine learning techniques indicate that the proposed technique is the optimal methodology currently available.In summary,the use of symbolic classification via genetic programming enables accurate turbulence detection from QAR data,comparable to that with established EDR approaches and surpassing that achieved with machine learning algorithms.This finding highlights the potential of integrating symbolic classifiers into turbulence monitoring systems to enhance civil aviation safety amidst rising environmental and operational hazards. 展开更多
关键词 turbulence detection symbolic classifier quick access recorder data
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Lithographic patterning of ferromagnetic FePt nanoparticles from a single-source bimetallic precursor containing hemiphasmidic structure for magnetic data recording media 被引量:1
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作者 Zhengong Meng Cheuk-Lam Ho +5 位作者 Hon-Fai Wong Zhen-Qiang Yu Nianyong Zhu Guijun Li Chi-Wah Leung Wai-Yeung Wong 《Science China Materials》 SCIE EI CSCD 2019年第4期566-576,共11页
Patterning of L10 FePt nanoparticles(NPs) with high coercivity offers a promising route to develop bit-patterned media(BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FeP... Patterning of L10 FePt nanoparticles(NPs) with high coercivity offers a promising route to develop bit-patterned media(BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FePt NPs and mass production of their nanopatterns has been a longstanding challenge. Here, highly efficient nanoimprint lithography was applied for large-scale universal patterning, which was achieved by imprinting the solution of a single-source bimetallic precursor. The rigid coplanar metallic cores and the surrounding flexible tails in the bimetallic complex permit the spontaneous molecular arrangements to form the highly ordered negative morphology replicated from the soft template.In-situ pyrolysis study was then investigated by one-pot pyrolysis of the precursor under an Ar/H2 atmosphere, and the resultant NPs were fully characterized to identify the phase,morphology and magnetic properties. Finally, highly-ordered patterns on certain substrates were preserved perfectly after pyrolysis and could be potentially utilized in magnetic data recording media. 展开更多
关键词 FEPT nanoparticles single-source BIMETALLIC precursors ONE-POT pyrolysis lithographic PATTERNING magnetic data recording media
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Maintaining Consistency Based on Timely Updating Records List in Workflow Data
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作者 WU Hongli YIN Baolin ZHAO Xiao XIANG Gang 《Wuhan University Journal of Natural Sciences》 CAS 2008年第4期481-484,共4页
In order to settle the problem of workflow data consis-tency under the distributed environment, an invalidation strategy based-on timely updating record list is put forward. The strategy adopting the method of updatin... In order to settle the problem of workflow data consis-tency under the distributed environment, an invalidation strategy based-on timely updating record list is put forward. The strategy adopting the method of updating the records list and the recovery mechanism of updating message proves the classical invalidation strategy. When the request cycle of duplication is too long, the strategy uses the method of updating the records list to pause for sending updating message; when the long cycle duplication is requested again, it uses the recovery mechanism to resume the updating message. This strategy not only ensures the consistency of the workflow data, but also reduces the unnecessary network traffic. From theoretical comparison with those common strategies, the unnecessary network traffic of this strategy is fewer and more stable. The simulation results validate this conclusion. 展开更多
关键词 distributed environment workflow data records list update cycle threshold consistency maintenance
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Data Processing of Fault Recorder in Power System
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作者 Yu Qin Yu Bai Minghao Wen 《Energy and Power Engineering》 2017年第4期46-52,共7页
This article studies the fault recorder in power system and introduces the Comtrade format. Andituses C++ programming to read recorded fault data and adopts Fourier analysis and symmetrical component method to filter ... This article studies the fault recorder in power system and introduces the Comtrade format. Andituses C++ programming to read recorded fault data and adopts Fourier analysis and symmetrical component method to filter and extract fundamental waves. Finally the effectiveness of the data processing method introduced in this paper is verified by CAAP software. 展开更多
关键词 FAULT recordER READ and Process recordED FAULT data RESULT Verification
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Application of fuzzy equivalence theory in data cleaning
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作者 李华旸 刘玉葆 李又奎 《Journal of Southeast University(English Edition)》 EI CAS 2004年第4期454-457,共4页
This paper presented a rule merging and simplifying method and an improved analysis deviation algorithm. The fuzzy equivalence theory avoids the rigid way (either this or that) of traditional equivalence theory. Durin... This paper presented a rule merging and simplifying method and an improved analysis deviation algorithm. The fuzzy equivalence theory avoids the rigid way (either this or that) of traditional equivalence theory. During a data cleaning process task, some rules exist such as included/being included relations with each other. The equivalence degree of the being-included rule is smaller than that of the including rule, so a rule merging and simplifying method is introduced to reduce the total computing time. And this kind of relation will affect the deviation of fuzzy equivalence degree. An improved analysis deviation algorithm that omits the influence of the included rules' equivalence degree was also presented. Normally the duplicate records are logged in a file, and users have to check and verify them one by one. It's time-cost. The proposed algorithm can save users' labor during duplicate records checking. Finally, an experiment was presented which demonstrates the possibility of the rule. 展开更多
关键词 data recording data warehouses database systems MERGING SEMANTICS
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Brittleness index predictions from Lower Barnett Shale well-log data applying an optimized data matching algorithm at various sampling densities 被引量:2
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作者 David A.Wood 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第6期444-457,共14页
The capability of accurately predicting mineralogical brittleness index (BI) from basic suites of well logs is desirable as it provides a useful indicator of the fracability of tight formations.Measuring mineralogical... The capability of accurately predicting mineralogical brittleness index (BI) from basic suites of well logs is desirable as it provides a useful indicator of the fracability of tight formations.Measuring mineralogical components in rocks is expensive and time consuming.However,the basic well log curves are not well correlated with BI so correlation-based,machine-learning methods are not able to derive highly accurate BI predictions using such data.A correlation-free,optimized data-matching algorithm is configured to predict BI on a supervised basis from well log and core data available from two published wells in the Lower Barnett Shale Formation (Texas).This transparent open box (TOB) algorithm matches data records by calculating the sum of squared errors between their variables and selecting the best matches as those with the minimum squared errors.It then applies optimizers to adjust weights applied to individual variable errors to minimize the root mean square error (RMSE)between calculated and predicted (BI).The prediction accuracy achieved by TOB using just five well logs (Gr,ρb,Ns,Rs,Dt) to predict BI is dependent on the density of data records sampled.At a sampling density of about one sample per 0.5 ft BI is predicted with RMSE~0.056 and R^(2)~0.790.At a sampling density of about one sample per0.1 ft BI is predicted with RMSE~0.008 and R^(2)~0.995.Adding a stratigraphic height index as an additional (sixth)input variable method improves BI prediction accuracy to RMSE~0.003 and R^(2)~0.999 for the two wells with only 1 record in 10,000 yielding a BI prediction error of>±0.1.The model has the potential to be applied in an unsupervised basis to predict BI from basic well log data in surrounding wells lacking mineralogical measurements but with similar lithofacies and burial histories.The method could also be extended to predict elastic rock properties in and seismic attributes from wells and seismic data to improve the precision of brittleness index and fracability mapping spatially. 展开更多
关键词 Well-log brittleness index estimates data record sample densities Zoomed-in data interpolation Correlation-free prediction analysis Mineralogical and elastic influences
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VB6.0数据环境(DataEnvironment)对象应用技术探讨 被引量:2
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作者 林民 朝鲁 松云 《微型电脑应用》 2001年第1期61-63,共3页
本文介绍了使用 VB6 .0数据环境 (Data Envi-ronment)对象进行数据库应用系统开发的优越性 ,具体举例说明了应用中值得注意的重要技术环节 ,从而使数据库应用系统的开发更加直观、简洁。
关键词 数据环境 数据命令 层次数据命令 VB6.0 数据库
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历史档案资源的数据化开发策略——丹麦Link-Lives项目的实践与启示
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作者 赵跃 杨蕊绮 段想 《档案与建设》 2026年第1期66-75,共10页
近年来,历史档案资源数据化开发引发关注,但以“人”为线索的整合与开发实践在我国还较为少见。为此,文章以丹麦Link-Lives项目为例,从多源档案资源的数据化、多层次的数据链接方法、数据处理过程的透明化、贯穿全程的公平性评估、用户... 近年来,历史档案资源数据化开发引发关注,但以“人”为线索的整合与开发实践在我国还较为少见。为此,文章以丹麦Link-Lives项目为例,从多源档案资源的数据化、多层次的数据链接方法、数据处理过程的透明化、贯穿全程的公平性评估、用户友好的数据传播策略等方面总结其实践经验与特色,从用户研究、方法探索、理念创新和跨界合作四个方面讨论了该项目对我国历史档案资源数据化开发的启示,即:重塑新思维,以用户需求为导向进行历史档案资源数据化开发;探索新方法,以人为主导推进档案资源数据化开发的人机协同;践行新理念,以实践为路径探索档案数据化与数据治理的融合;跨领域合作,依靠社会多方力量应对档案资源数据化开发的挑战。 展开更多
关键词 历史大数据 档案数据 数据整合 记录链接 档案数据化
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ADO对象的Data Shape技术及其应用 被引量:1
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作者 彭江平 胡黩武 谢勇 《电脑开发与应用》 2000年第9期20-22,共3页
讨论了ADO对象引入的Data Shape与层次结构记录集技术, 并通过一些具体的实例说明了该技术在各种的环境下的具体使用方法。这类技术为复杂的主 细表操作与分类统计计算问题提供了一个比较简单而又直观的处理方法。
关键词 ADO 主细表 记录集 管理信息系统
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基于数据挖掘的复发性流产证治规律研究
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作者 张琪 魏凤琴 《中国科技术语》 2026年第1期143-145,共3页
文章基于文献数据挖掘探析复发性流产的病症特点及用药规律,通过计算机检索中国知网,根据纳入排除标准获取文献,并应用古今医案云平台对证候、药物进行统计挖掘分析,最终共纳入文献449篇,挖掘出复发性流产的主要证型有脾肾两虚证、气血... 文章基于文献数据挖掘探析复发性流产的病症特点及用药规律,通过计算机检索中国知网,根据纳入排除标准获取文献,并应用古今医案云平台对证候、药物进行统计挖掘分析,最终共纳入文献449篇,挖掘出复发性流产的主要证型有脾肾两虚证、气血亏虚证等,发现其虚证多见,病位涉及肾、脾、肝,遵循扶正祛邪、重补先天、肝脾肾同治的用药特点。 展开更多
关键词 复发性流产 数据挖掘 医案 证治规律
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基于Flink的流批一体数据集成平台构建
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作者 金鑫会 《计算机应用文摘》 2026年第2期122-124,共3页
以医院数据中台建设为背景,探讨基于Apache Flink构建流批一体数据集成平台的技术方案与实施路径。针对传统医疗数据架构中存在的实时性差、“数据孤岛”、口径不一致等问题,提出基于Flink SQL与数据湖(Iceberg)的流批一体架构,实现电... 以医院数据中台建设为背景,探讨基于Apache Flink构建流批一体数据集成平台的技术方案与实施路径。针对传统医疗数据架构中存在的实时性差、“数据孤岛”、口径不一致等问题,提出基于Flink SQL与数据湖(Iceberg)的流批一体架构,实现电子病历、影像系统、实验室数据等异构数据源的实时整合与批量分析。 展开更多
关键词 Flink 医疗数据 数据湖 电子病历 影像系统
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使用常规收集的卫生数据开展药物流行病学研究报告规范(RECORD-PE)及解读 被引量:1
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作者 胡方圆 叶小飞 +2 位作者 许金芳 郭晓晶 贺佳 《中国药物警戒》 2019年第3期144-148,153,共6页
常规收集的卫生数据在药物流行病学研究中发挥着越来越重要的作用。根据STROBE声明拓展而来的RECORD声明是目前利用常规收集卫生数据进行研究的主要指南,但RECORD声明并不完全适用于药物流行病学研究,RECORD-PE(RECORD for Pharmacoepid... 常规收集的卫生数据在药物流行病学研究中发挥着越来越重要的作用。根据STROBE声明拓展而来的RECORD声明是目前利用常规收集卫生数据进行研究的主要指南,但RECORD声明并不完全适用于药物流行病学研究,RECORD-PE(RECORD for Pharmacoepidemiology)声明在RECORD声明基础上,针对药物流行病学研究扩展了15个条目。本文对RECORD-PE进行了详细解读,并给出了相应的实例,便于我国学者更好地掌握RECORD-PE声明并进行利用。 展开更多
关键词 常规收集的卫生数据 药物流行病学 record-PE声明 指南
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计量技术机构人员技术档案信息化管理系统的研究
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作者 李雪飞 《计量与测试技术》 2026年第1期128-130,共3页
为实现多源数据融合与流程标准化管理,本文针对大数据时代背景下计量技术机构传统人员技术档案管理存在效率低下、数据孤岛及安全风险等问题,通过构建数字化档案管理系统,集成档案录入、审核、查询、统计与安全模块。研究表明,该系统不... 为实现多源数据融合与流程标准化管理,本文针对大数据时代背景下计量技术机构传统人员技术档案管理存在效率低下、数据孤岛及安全风险等问题,通过构建数字化档案管理系统,集成档案录入、审核、查询、统计与安全模块。研究表明,该系统不仅能通过权限控制、加密技术及智能分析,有效破解传统档案管理瓶颈,推动档案价值从“资源保管”向“数据驱动决策”转型,而且可结合数字孪生技术深化应用,为机构的数字化转型提供持续支撑。 展开更多
关键词 计量技术机构 人员技术档案 信息化管理 数据安全
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Flight Characteristics Analysis Based on QAR Data of a Jet Transport During Landing at a High-altitude Airport 被引量:5
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作者 C.Edward Lan WU Kaiyuan YU Jiang 《Chinese Journal of Aeronautics》 SCIE EI CSCD 2012年第1期13-24,共12页
Flight data of a twin-jet transport aircraft in revenue flight are analyzed for potential safety problems. Data from the quick access recorder (QAR) are first filtered through the kinematic compatibility analysis. T... Flight data of a twin-jet transport aircraft in revenue flight are analyzed for potential safety problems. Data from the quick access recorder (QAR) are first filtered through the kinematic compatibility analysis. The filtered data are then organized into longitudinal- and lateral-directional aerodynamic model data with dynamic ground effect. The dynamic ground effect requires the radio height and sink rate in the models. The model data are then refined into numerical models through a fuzzy logic algorithm without data smoothing in advance. These numerical models describe nonlinear and unsteady aerodynamics and are used in nonlinear flight dynamics simulation. For the jet transport under study, it is found that the effect of crosswind is significant enough to excite the Dutch roll motion. Through a linearized analysis in flight dynamics at every instant of time, the Dutch roll motion is found to be in nonlinear oscillation without clear damping of the amplitude. In the analysis, all stability derivatives vary with time and hence are nonlinear functions of state variables. Since the Dutch roll motion is not damped despite the fact that a full-time yaw damper is engaged, it is concluded that the design data for the yaw damper is not sufficiently realistic and the contribution of time derivative of sideslip angle to damping should be considered. As a result of nonlinear flight simulation, the vertical wind acting on the aircraft is estimated to be mostly updraft which varies along the flight path before touchdown. Varying updraft appears to make the descent rate more difficult to control to result in a higher g-load at touchdown. 展开更多
关键词 jet transport unsteady aerodynamics nonlinear aerodynamics flight dynamics flight safety quick access recorder data
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Data Report在复杂报表中的应用研究
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作者 宋秋云 翟延富 董祥军 《微型电脑应用》 2006年第10期53-55,67,共3页
本文介绍了目前Visual Basic6.0中制作复杂报表的几种方法:基于Excel生成复杂报表、利用水晶报表制作复杂报表、使用第三方控件生成复杂报表以及用VB自带的报表设计器(Data Report)生成报表等,比较了它们的优缺点,据此提出使用VB自带的D... 本文介绍了目前Visual Basic6.0中制作复杂报表的几种方法:基于Excel生成复杂报表、利用水晶报表制作复杂报表、使用第三方控件生成复杂报表以及用VB自带的报表设计器(Data Report)生成报表等,比较了它们的优缺点,据此提出使用VB自带的Data Report制作报表的优越性,并以大坝渗流分析系统的一个复杂报表实例说明使用Data Report制作复杂报表的具体方法和步骤。 展开更多
关键词 data REPORT 数据环境 记录集 水晶报表
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Research on the completeness of earthquake data in the Chinese mainland(I)──North China
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作者 黄玮琼 李文香 曹学锋 《Acta Seismologica Sinica(English Edition)》 CSCD 1994年第3期351-359,共9页
In terms of the temporal-spatial distribution features of earthquakes, we study the completeness of historical data in North China where there is the most plenty historical data and with the longest record history by ... In terms of the temporal-spatial distribution features of earthquakes, we study the completeness of historical data in North China where there is the most plenty historical data and with the longest record history by some meth ods of analysis and comparison. The results are obtained for events with Ms≥4 are largely complete since 1484 in North China (except Huanghai sea region and remote districts, such as Nei Mongol Autonomous region), but quakes with Ms≥6 are largely complete since 1291 in the middle and lower reaches of the Yellow River. 展开更多
关键词 COMPLETENESS earthquake data record capability mean annual rate proportionality factor
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基于同源录波数据比对的继电保护采样回路异常检测方法 被引量:4
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作者 戴志辉 张富泽 韩笑 《电力系统保护与控制》 北大核心 2025年第1期147-159,共13页
处于改建阶段的智能变电站采样模式复杂,继电保护装置难以发现采样回路轻微异常,导致回路隐患暴露时间严重滞后。针对上述问题,分析改建时期智能变电站的采样模式和二次设备配置情况,提出基于同源录波数据比对的继电保护采样回路异常检... 处于改建阶段的智能变电站采样模式复杂,继电保护装置难以发现采样回路轻微异常,导致回路隐患暴露时间严重滞后。针对上述问题,分析改建时期智能变电站的采样模式和二次设备配置情况,提出基于同源录波数据比对的继电保护采样回路异常检测方法。首先,利用双向编码器表征(bidirectional encoder representations from transformers,BERT)语言模型与余弦相似度算法,实现同源录波数据的通道匹配。然后,利用重采样技术和曼哈顿距离完成波形的采样频率统一与时域对齐。最后,基于动态时间规整(dynamic time warping,DTW)算法提出改进算法,并结合采样点偏移量共同设置采样回路的异常判据。算例分析表明,该方法可以完成录波数据的同源通道匹配,实现波形的一致性对齐,并且相比于传统DTW算法,改进DTW算法对异常状态识别的灵敏性和准确性更高。根据异常判据能够有效检测继电保护采样回路的异常状态,确保了智能变电站的安全可靠运行。 展开更多
关键词 继电保护装置 采样回路 异常检测 改进DTW算法 录波数据
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