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基于Anomaly Transformer的轨道几何不平顺异常检测方法 被引量:1
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作者 杨森 刘金朝 +1 位作者 刘钰 杨飞 《铁道学报》 北大核心 2025年第6期122-131,共10页
使用传统信号处理方法在轨道几何不平顺异常数据检测中受限于先验定义的异常特征,导致其无法有效捕捉复杂数据中一些微小变化和未知模式,限制其应对多变和复杂情况的能力。提出基于注意力机制Anomaly Transformer的无监督深度神经网络... 使用传统信号处理方法在轨道几何不平顺异常数据检测中受限于先验定义的异常特征,导致其无法有效捕捉复杂数据中一些微小变化和未知模式,限制其应对多变和复杂情况的能力。提出基于注意力机制Anomaly Transformer的无监督深度神经网络的轨道几何不平顺数据异常检测模型,采用双分支注意力机制同时对先验关联和序列关联进行建模,实现在无需先验信息和专家知识条件下,轨道几何异常检测数据特征的自动识别。研究结果表明:此模型可实现轨道不平顺异常数据中局部毛刺异常、道岔轨距加宽异常、单边轨距波形拉直线异常、检测数据分布异常的精准识别,识别准确率达到95.53%、召回率98.72%、F1分数97.10%;同时验证了在不同速度等级线路、不同检测车的泛化性能,识别准确率不低于90.0%,召回率不低于91%,说明模型具有良好的鲁棒性和泛化性能。 展开更多
关键词 轨道不平顺 轨道几何 异常检测 TRANSFORMER 无监督学习
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Real-Time Smart Meter Abnormality Detection Framework via End-to-End Self-Supervised Time-Series Contrastive Learning with Anomaly Synthesis
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作者 WANG Yixin LIANG Gaoqi +1 位作者 BI Jichao ZHAO Junhua 《南方电网技术》 北大核心 2025年第7期62-71,89,共11页
The rapid integration of Internet of Things(IoT)technologies is reshaping the global energy landscape by deploying smart meters that enable high-resolution consumption monitoring,two-way communication,and advanced met... The rapid integration of Internet of Things(IoT)technologies is reshaping the global energy landscape by deploying smart meters that enable high-resolution consumption monitoring,two-way communication,and advanced metering infrastructure services.However,this digital transformation also exposes power system to evolving threats,ranging from cyber intrusions and electricity theft to device malfunctions,and the unpredictable nature of these anomalies,coupled with the scarcity of labeled fault data,makes realtime detection exceptionally challenging.To address these difficulties,a real-time decision support framework is presented for smart meter anomality detection that leverages rolling time windows and two self-supervised contrastive learning modules.The first module synthesizes diverse negative samples to overcome the lack of labeled anomalies,while the second captures intrinsic temporal patterns for enhanced contextual discrimination.The end-to-end framework continuously updates its model with rolling updated meter data to deliver timely identification of emerging abnormal behaviors in evolving grids.Extensive evaluations on eight publicly available smart meter datasets over seven diverse abnormal patterns testing demonstrate the effectiveness of the proposed full framework,achieving average recall and F1 score of more than 0.85. 展开更多
关键词 abnormality detection cyber-physical security anomaly synthesis contrastive learning time-series
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基于D^(2) GANomaly的轮胎缺陷检测研究
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作者 刘韵婷 冯欣悦 +1 位作者 李思维 张智星 《电子测量与仪器学报》 北大核心 2025年第8期91-100,共10页
针对GANomaly模型潜在向量对正样本特征表征能力不足、解码器重构图像质量欠佳以及判别器判别能力不足的问题,提出一种基于D^(2)GANomaly的轮胎X光图像缺陷检测方法。首先,在编码器中引入多尺度动态残差模块(MDRB),通过可变核卷积(AKCo... 针对GANomaly模型潜在向量对正样本特征表征能力不足、解码器重构图像质量欠佳以及判别器判别能力不足的问题,提出一种基于D^(2)GANomaly的轮胎X光图像缺陷检测方法。首先,在编码器中引入多尺度动态残差模块(MDRB),通过可变核卷积(AKConv)与残差连接的组合,动态融合多尺度特征,提高细粒度特征提取能力;其次,在解码器部分引入通道残差子像素解码器(CRSD),利用双解码器并行学习,优化复杂纹理和细节的重建质量;最后,判别网络采用二元并行判别网络(DDMN),通过可切换空洞卷积(SAC)选取最优空洞扩张系数,增强模型对轮胎X光图像中不同大小的缺陷检测能力,进而提高判别能力。实验结果表明,在受试者工作特征曲线下面积(AUC)与平均精度(AP)两项核心性能指标上,所提方法均实现了显著提升,相较于原始模型GANomaly AUC值提升了13.7%,AP值提升了16.4%。由此可见,改进后的模型有效提升了轮胎缺陷的检测精度。 展开更多
关键词 生成对抗网络 异常检测 残差结构 可变核卷积
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典型断层形变前兆异常的落实与思考
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作者 薄万举 徐东卓 +1 位作者 李腊月 陈长云 《地震研究》 北大核心 2026年第1期65-74,共10页
对中国大陆自1966年邢台7.2级地震以来在各主要地震带建立的跨断层测量场地获得的断层形变资料进行了梳理,对其中出现的单项断层形变异常、群体性准同步断层形变异常的特点及其在地震分析预测中的应用分别给出了实例;利用预测100 km内1... 对中国大陆自1966年邢台7.2级地震以来在各主要地震带建立的跨断层测量场地获得的断层形变资料进行了梳理,对其中出现的单项断层形变异常、群体性准同步断层形变异常的特点及其在地震分析预测中的应用分别给出了实例;利用预测100 km内1年内可能发生7级以上强震的预测指标(即满足K≥5),对所有资料出现的巨大幅度的断层形变异常变化进行了检索,共得到5项异常(同一测量场地出现多个相关异常按1项计算),简称为“巨幅异常”。结果表明:5项巨幅异常中有3项符合7级以上强震的预测指标,分别对应了1976年唐山7.8级地震、1996年丽江7.0级地震和2008年汶川8.0级地震。最后给出了结论建议,供跨断层形变资料分析、跨断层场地维护改造、强震预测及相关对策研究等工作参考。 展开更多
关键词 断层形变 强震预测 形变 前兆异常
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地震水文地质学:基于灾害视角的“水岩相互作用”
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作者 史浙明 王广才 +1 位作者 晏锐 齐之钰 《地学前缘》 北大核心 2026年第1期80-94,共15页
地震水文地质学是研究地震与地下水相互作用的一门学科,与传统水文地质研究不同,其主要关注因地震等地壳运动产生的含水介质变形而导致的地下水文过程演化。本文从地壳变形与地下水动态、地震地下水前兆异常、地震引起的同震及震后响应... 地震水文地质学是研究地震与地下水相互作用的一门学科,与传统水文地质研究不同,其主要关注因地震等地壳运动产生的含水介质变形而导致的地下水文过程演化。本文从地壳变形与地下水动态、地震地下水前兆异常、地震引起的同震及震后响应以及地震导致的水文地质参数变化等方面进行综述,重点介绍了近二十年以来的进展。线孔弹性理论的发展为定量刻画地震等地壳运动与地下水动态的关系提供了理论基础。地下流体前兆异常在近年来的地震预测实践中起到了较好的参考作用,其中地下水地球化学指标监测及大规模地球化学观测网络的建设是一大亮点。与此同时,建立地下水物理与化学动态的前兆异常耦合机理模型以及发展机器学习等新兴的前兆信号提取方法是未来需要重点突破的方向。地震引起的含水层介质渗透性的改变及其导致的水量交换和水化学的动态变化是解释同震及震后地下水响应的主要机理,基于地下水对潮汐、气压等周期性信号响应的含水层参数识别为连续获取水文地质参数提供了新途径,然而现有潮汐和气压响应的解析模型在参数计算方面往往存在多解性问题,发展新的模型和方法以降低计算结果的不确定性是未来需要考虑的方向。为了更好地理解地震与地下水系统间的相互作用,在前期研究基础上建立涵盖温泉、地下水监测井的断裂带试验场,开展水位、水温、流量、化学组分、形变及地震波的综合观测,是深化地震水文地质学科理论发展的基础。 展开更多
关键词 地震 地下水 含水层参数 地球潮汐 气压 前兆异常
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腾冲火山温泉流体地球化学地震 短临前兆异常特征
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作者 周晓成 曾召君 +4 位作者 何苗 天娇 颜玉聪 王昱文 姚炳宇 《地震研究》 北大核心 2026年第1期51-64,共14页
活火山可以从地球深处向地表有效转送能量、物质和信息。2015—2023年对腾冲火山热海地热田3个温泉进行了地震地球化学前兆研究,采用离散采样和连续采样的方法监测了泉水的水文地球化学参数。在叠水河温泉搭建了一个自动连续监测站,配... 活火山可以从地球深处向地表有效转送能量、物质和信息。2015—2023年对腾冲火山热海地热田3个温泉进行了地震地球化学前兆研究,采用离散采样和连续采样的方法监测了泉水的水文地球化学参数。在叠水河温泉搭建了一个自动连续监测站,配备了可以测量气体流量和二氧化碳浓度的传感器。分析数据表明:①2015—2022年大滚锅温泉气体中空气校正3He/4He平均值为4.25 Ra(Ra=空气3He/4He=1.39×10^(-6))。2021年6月21日盈江M_(S)5.0地震之前,大滚锅温泉气的氦同位素比值高于平均值,表明热海地区输入了富3He脱气岩浆。在2023年5月2日隆阳M_(S)5.2地震前,叠水河富CO_(2)泉实测气体流量的显著变化显示了早期的地震前兆信号。②大滚锅温泉和叠水河温泉在盈江M_(S)5.0、隆阳M_(S)5.2和芒市M_(S)5.0地震前存在短期(6~96 d)的水化学成分(δD、δ18 O、Cl^(-)和SO_(4)^(2-))前兆异常。 展开更多
关键词 流体地球化学 氦同位素 温泉 地震前兆异常 腾冲火山
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基于重力卫星和基流分割方法的青藏高原东部地下水储量变化分析
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作者 刘苏仪 韩宁 +4 位作者 黄志勇 郑龙群 张翀 宫辉力 潘云 《地学前缘》 北大核心 2026年第1期470-482,共13页
在全球变暖与人类活动加剧的背景下,定量解析青藏高原地下水储量时空演变是揭示“亚洲水塔”水循环变化机制的关键环节。联合重力卫星GRACE/GRACE-FO、全球陆面过程模型和全球水文模型反演青藏高原东部地下水储量变化,并将反演结果与基... 在全球变暖与人类活动加剧的背景下,定量解析青藏高原地下水储量时空演变是揭示“亚洲水塔”水循环变化机制的关键环节。联合重力卫星GRACE/GRACE-FO、全球陆面过程模型和全球水文模型反演青藏高原东部地下水储量变化,并将反演结果与基流分割所得结果进行对比验证。重力卫星数据反演结果表明,2003—2022年,青藏高原东部的陆地水储量变化以土壤水为主(贡献率为48.45%),其次是地下水(贡献率为32.69%),其中3个子流域(长江上游、雅砻江、大渡河,面积占比为52.7%)的陆地水储量变化以土壤水占主导,其余7个子流域(面积占比为47.3%)的陆地水储量变化以地下水占主导。青藏高原东部的地下水储量变化呈显著增加趋势((2.11±0.57)mm/a),青藏高原东部10个子流域中,7个子流域的基流分割所得地下水储量变化与重力卫星数据反演结果均呈增加趋势(相关系数r=0.78),但基流分割得到的地下水储量变化趋势明显偏小,其可能原因包括:基流退水过程中集水区面积的持续缩减;基于数值模拟的基流分割方法对研究区基流的系统性低估;重力卫星数据处理过程中的误差。多元回归分析结果显示,降水、气温和向下短波辐射共同驱动了研究区地下水储量增加趋势。 展开更多
关键词 重力卫星 GRACE/GRACE-FO 基流分割 地下水储量变化 青藏高原 气候变化
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AnomalyDetect:一种基于欧式距离的在线异常检测算法 被引量:14
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作者 霍文君 王伟 李文 《中国科学技术大学学报》 CAS CSCD 北大核心 2019年第7期555-563,571,共10页
异常检测是数据挖掘中的一项关键技术,在计算机和互联网领域有广泛的应用,包括网络安全、图像识别、智能运维等,特别是智能运维,近几年取得了长足的发展.已有的异常检测算法会有低准确度、离线、无法自动更新等问题.为此对智能运维背景... 异常检测是数据挖掘中的一项关键技术,在计算机和互联网领域有广泛的应用,包括网络安全、图像识别、智能运维等,特别是智能运维,近几年取得了长足的发展.已有的异常检测算法会有低准确度、离线、无法自动更新等问题.为此对智能运维背景下的真实异常检测问题进行研究,构建高准确度、在线、通用异常检测算法,并据此在已有时间序列异常检测算法的基础上,提出了一种新的基于欧式距离的在线异常检测算法.通过实际的运维时序数据实验,发现该算法可以实时快速准确地检测流式时间序列数据中的异常数据,验证了该算法的有效性. 展开更多
关键词 异常检测 时间序列 在线算法 欧式距离 智能运维
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Range anomaly suppression based on neighborhood pixels detection in ladar range images 被引量:2
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作者 Mingbo Zhao Jun He +1 位作者 Zaiqi Lu Qiang Fu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第1期68-75,共8页
Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear ... Research on the range anomaly suppression algorithm in laser radar (ladar) range images is significant in the application and development of ladar. But most of existing algorithms cannot protect the edge and linear target well while suppressing the range anomaly. Aiming at this problem, the differences among the edge, linear target, and range anomaly are analyzed and a novel algo- rithm based on neighborhood pixels detection is proposed. Firstly, the range differences between current pixel and its neighborhood pixels are calculated. Then, the number of neighborhood pixels is detected by the range difference threshold. Finally, whether the current pixel is a range anomaly is distinguished by the neighbor- hood pixel number threshold. Experimental results show that the new algorithm not only has a better range anomaly suppression performance and higher efficiency, but also protects the edge and linear target preferably compared with other algorithms. 展开更多
关键词 image processing range anomaly suppression neigh-borhood p xe s detection linear target laser radar (ladar).
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A background refinement method based on local density for hyperspectral anomaly detection 被引量:5
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作者 ZHAO Chun-hui WANG Xin-peng +1 位作者 YAO Xi-feng TIAN Ming-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第1期84-94,共11页
For anomaly detection,anomalies existing in the background will affect the detection performance.Accordingly,a background refinement method based on the local density is proposed to remove the anomalies from thebackgr... For anomaly detection,anomalies existing in the background will affect the detection performance.Accordingly,a background refinement method based on the local density is proposed to remove the anomalies from thebackground.In this work,the local density is measured by its spectral neighbors through a certain radius which is obtained by calculating the mean median of the distance matrix.Further,a two-step segmentation strategy is designed.The first segmentation step divides the original background into two subsets,a large subset composed by background pixels and a small subset containing both background pixels and anomalies.The second segmentation step employing Otsu method with an aim to obtain a discrimination threshold is conducted on the small subset.Then the pixels whose local densities are lower than the threshold are removed.Finally,to validate the effectiveness of the proposed method,it combines Reed-Xiaoli detector and collaborative-representation-based detector to detect anomalies.Experiments are conducted on two real hyperspectral datasets.Results show that the proposed method achieves better detection performance. 展开更多
关键词 hyperspectral imagery anomaly detection background refinement the local density
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Mineralization-related geochemical anomalies derived from stream sediment geochemical data using multifractal analysis in Pangxidong area of Qinzhou-Hangzhou tectonic joint belt, Guangdong Province, China 被引量:5
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作者 张焱 周永章 +8 位作者 王林峰 王正海 何俊国 安燕飞 李红中 曾长育 梁锦 吕文超 高乐 《Journal of Central South University》 SCIE EI CAS 2013年第1期184-192,共9页
Distinguishing geochemical anomalies from background is a basic task in exploratory geochemistry. The derivation of geochemical anomalies from stream sediment geochemical data and the decomposition of these anomalies ... Distinguishing geochemical anomalies from background is a basic task in exploratory geochemistry. The derivation of geochemical anomalies from stream sediment geochemical data and the decomposition of these anomalies into their component patterns were described. A set of stream sediment geochemical data was obtained for 1 880 km 2 of the Pangxidong area, which is in the southern part of the recently recognized Qinzhou-Hangzhou joint tectonic belt. This belt crosses southern China and tends to the northwest (NE) direction. The total number of collected samples was 7 236, and the concentrations of Ag, Au, Cu, As, Pb and Zn were measured for each sample. The spatial combination distribution law of geochemical elements and principal component analysis (PCA) were used to construct combination models for the identification of combinations of geochemical anomalies. Spectrum-area (S-A) fractal modeling was used to strengthen weak anomalies and separate them from the background. Composite anomaly modeling was combined with fractal filtering techniques to process and analyze the geochemical data. The raster maps of Au, Ag, Cu, As, Pb and Zn were obtained by the multifractal inverse distance weighted (MIDW) method. PCA was used to combine the Au, Ag, Cu, As, Pb, and Zn concentration values. The S-A fractal method was used to decompose the first component pattern achieved by the PCA. The results show that combination anomalies from a combination of variables coincide with the known mineralization of the study area. Although the combination anomalies cannot reflect local anomalies closely enough, high-anomaly areas indicate good sites for further exploration for unknown deposits. On this basis, anomaly and background separation from combination anomalies using fractal filtering techniques can provide guidance for later work. 展开更多
关键词 geochemical anomalies fractal modeling principal component analysis Qinzhou-Hangzhou joint tectonic belt streamsediments
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Approach based on wavelet analysis for detecting and amending anomalies in dataset 被引量:1
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作者 彭小奇 宋彦坡 +1 位作者 唐英 张建智 《Journal of Central South University of Technology》 EI 2006年第5期491-495,共5页
It is difficult to detect the anomalies whose matching relationship among some data attributes is very different from others’ in a dataset. Aiming at this problem, an approach based on wavelet analysis for detecting ... It is difficult to detect the anomalies whose matching relationship among some data attributes is very different from others’ in a dataset. Aiming at this problem, an approach based on wavelet analysis for detecting and amending anomalous samples was proposed. Taking full advantage of wavelet analysis’ properties of multi-resolution and local analysis, this approach is able to detect and amend anomalous samples effectively. To realize the rapid numeric computation of wavelet translation for a discrete sequence, a modified algorithm based on Newton-Cores formula was also proposed. The experimental result shows that the approach is feasible with good result and good practicality. 展开更多
关键词 data preprocessing wavelet analysis anomaly detecting data mining
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An anomaly detection method for spacecraft solar arrays based on the ILS-SVM model 被引量:4
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作者 WANG Yu ZHANG Tao +1 位作者 HUI Jianjiang LIU Yajie 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第2期515-529,共15页
Solar arrays are important and indispensable parts of spacecraft and provide energy support for spacecraft to operate in orbit and complete on-orbit missions.When a spacecraft is in orbit,because the solar array is ex... Solar arrays are important and indispensable parts of spacecraft and provide energy support for spacecraft to operate in orbit and complete on-orbit missions.When a spacecraft is in orbit,because the solar array is exposed to the harsh space environment,with increasing working time,the performance of its internal electronic components gradually degrade until abnormal damage occurs.This damage makes solar array power generation unable to fully meet the energy demand of a spacecraft.Therefore,timely and accurate detection of solar array anomalies is of great significance for the on-orbit operation and maintenance management of spacecraft.In this paper,we propose an anomaly detection method for spacecraft solar arrays based on the integrated least squares support vector machine(ILS-SVM)model:it selects correlated telemetry data from spacecraft solar arrays to form a training set and extracts n groups of training subsets from this set,then gets n corresponding least squares support vector machine(LS-SVM)submodels by training on these training subsets,respectively;after that,the ILS-SVM model is obtained by integrating these submodels through a weighting operation to increase the prediction accuracy and so on;finally,based on the obtained ILS-SVM model,a parameterfree and unsupervised anomaly determination method is proposed to detect the health status of solar arrays.We use the telemetry data set from a satellite in orbit to carry out experimental verification and find that the proposed method can diagnose solar array anomalies in time and can capture the signs before a solar array anomaly occurs,which reflects the applicability of the method. 展开更多
关键词 spacecraft solar array anomaly detection integrated least squares support vector machine(ILS-SVM) induced ordered weighted average(IOWA)operator integrated model
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A method for extracting anomaly map of Au and As using combination of U-statistic and Euclidean distance methods in Susanvar district,Iran
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作者 Seyyed Saeed Ghannadpour Ardeshir Hezarkhani Mostafa Sharifzadeh 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第11期2693-2704,共12页
Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemi... Quantitative descriptions of geochemical patterns and providing geochemical anomaly map are important in applied geochemistry. Several statistical methodologies are presented in order to identify and separate geochemical anomalies. The U-statistic method is one of the most important structural methods and is a kind of weighted mean that surrounding points of samples are considered in U value determination. However, it is able to separate the different anomalies based on only one variable. The main aim of the presented study is development of this method in a multivariate mode. For this purpose, U-statistic method should be combined with a multivariate method which devotes a new value to each sample based on several variables. Therefore, at the first step, the optimum p is calculated in p-norm distance and then U-statistic method is applied on p-norm distance values of the samples because p-norm distance is calculated based on several variables. This method is a combination of efficient U-statistic method and p-norm distance and is used for the first time in this research. Results show that p-norm distance of p=2(Euclidean distance) in the case of a fact that Au and As can be considered optimized p-norm distance with the lowest error. The samples indicated by the combination of these methods as anomalous are more regular, less dispersed and more accurate than using just the U-statistic or other nonstructural methods such as Mahalanobis distance. Also it was observed that the combination results are closely associated with the defined Au ore indication within the studied area. Finally, univariate and bivariate geochemical anomaly maps are provided for Au and As, which have been respectively prepared using U-statistic and its combination with Euclidean distance method. 展开更多
关键词 mineral anomaly Susanvar DISTRICT U-STATISTIC METHOD Euclidean distance BIVARIATE anomaly MAP
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A Statistical Study on Seismo-Ionospheric Anomalies of the Total Electron Content for the Period of 56 M≥6.0 Earthquakes Occurring in China During 1998—2012 被引量:7
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作者 Liu J Y Chen C H +1 位作者 Tsai H F Le H 《空间科学学报》 CAS CSCD 北大核心 2013年第3期258-269,共12页
This paper reports statistical results of Seismo-Ionospheric Anomalies(SIAs) of the Total Electron Content(TEC) in the Global Ionosphere Map(GIM) associated with 56 M≥6.0 earthquakes in China during 1998—2012.To det... This paper reports statistical results of Seismo-Ionospheric Anomalies(SIAs) of the Total Electron Content(TEC) in the Global Ionosphere Map(GIM) associated with 56 M≥6.0 earthquakes in China during 1998—2012.To detect SIA,a quartile-based(i.e.median-based) process is performed.TEC anomalies for the period of earthquakes without being led by magnetic storms about 10 days are further isolated and examined to confirm the SIP existence.Results show that SIA is the TEC significantly decrease in the afternoon period 2—9 days before the earthquakes in China,which is in a good agreement with the SIA appearing before the 12 May 2008 M 8.0 Wenchuan earthquake. 展开更多
关键词 电离层异常 地震发生 总电子含量 中国 统计 SIAS TEC GIM
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ANALYSIS ON SHORT-TERM PRECURSORY ANOMALIES AND SEQUENCE CHARACTERISTIC OF NINGLANG EARTHQUAKE 1998
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作者 Mu Yayuan 《地学前缘》 EI CAS CSCD 2000年第S1期439-439,共1页
From Octobet 1998 to January 1999,5 earthquakes ( M s≥5) occurred between Ninglang and Yanyuan counties (27°07′~27°12′N,100°40′~101°00′E area).They were situated in 140km southwest of the Xi... From Octobet 1998 to January 1999,5 earthquakes ( M s≥5) occurred between Ninglang and Yanyuan counties (27°07′~27°12′N,100°40′~101°00′E area).They were situated in 140km southwest of the Xichang.Among them,the largest one is M s 6 2 on November 19,1998.Based on small seismic data by the seismic remote sensing station of Xichang and the seismological station of Muli,and regional observation data,passing through careful observation and scientific analyses,we had made better forecasts before the earthquakes.That results obvious social benefits.By processing data of precursory earthquakes,such as,original observation data of total geomagnetic intensity from the station of Xichang,pressure capacitance stressometer and quartz horizaontal pendulum tiltmeter from the Xiaomiao station of Xichang,we summarized the sequence characteristics of the series earthquakes.The information about short\|term anomaly of gruond strain,total geomagnetic intensity and ground tilt before the earthquake is emphatically explained. 展开更多
关键词 Ninglang EARTHQUAKE PRECURSOR seismic SWARM ground TILT short\|term ANOMALIES
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Anomaly Detection Method Using Feature Reconstruction Based Knowledge Distillation
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作者 ZHU Xin-yu SI Zhan-jun ZHANG Ying-xue 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第4期115-124,236,共11页
In recent years,anomaly detection has attracted much attention in industrial production.As traditional anomaly detection methods usually rely on direct comparison of samples,they often ignore the intrinsic relationshi... In recent years,anomaly detection has attracted much attention in industrial production.As traditional anomaly detection methods usually rely on direct comparison of samples,they often ignore the intrinsic relationship between samples,resulting in poor accuracy in recognizing anomalous samples.To address this problem,a knowledge distillation anomaly detection method based on feature reconstruction was proposed in this study.Knowledge distillation was performed after inverting the structure of the teacher-student network to avoid the teacher-student network sharing the same inputs and similar structure.Representability was improved by using feature splicing to unify features at different levels,and the merged features were processed and reconstructed using an improved Transformer.The experimental results show that the proposed method achieves better performance on the MVTec dataset,verifying its effectiveness and feasibility in anomaly detection tasks.This study provides a new idea to improve the accuracy and efficiency of anomaly detection. 展开更多
关键词 Feature Reconstruction anomaly Detection Distillation Mechanism Industrial Production
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Deep learning-based method for detecting anomalies in electromagnetic environment situation
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作者 Wei-lin Hu Lun-wen Wang +2 位作者 Chuang Peng Ran-gang Zhu Meng-bo Zhang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第8期231-241,共11页
The anomaly detection of electromagnetic environment situation(EMES) has essential reference value for electromagnetic equipment behavior cognition and battlefield threat assessment.In this paper,we proposed a deep le... The anomaly detection of electromagnetic environment situation(EMES) has essential reference value for electromagnetic equipment behavior cognition and battlefield threat assessment.In this paper,we proposed a deep learning-based method for detecting anomalies in EMES to address the problem of relatively low efficiency of electromagnetic environment situation anomaly detection(EMES-AD).Firstly,the convolutional kernel extracts the static features of different regions of the EMES.Secondly,the dynamic features of the region are obtained by using a recurrent neural network(LSTM).Thirdly,the Spatio-temporal features of the region are recovered by using a de-convolutional network and then fused to predict the EMES.The structural similarity algorithm(SSIM) is used to determine whether it is anomalous.We developed the detection framework,de-signed the network parameters,simulated the data sets containing different anomalous types of EMES,and carried out the detection experiments.The experimental results show that the proposed method is effective. 展开更多
关键词 Electromagnetic environment situation(EMES) anomaly detection(AD) Regional features integration LSTM CNN
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利用多层次特征融合网络的图像异常检测算法 被引量:2
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作者 唐俊 左金梅 +2 位作者 王科 张艳 王年 《国防科技大学学报》 北大核心 2025年第2期173-182,共10页
图像异常检测旨在识别并定位图像中的异常区域,针对现有算法中不同层次特征信息利用不充分的问题,提出了基于多层次特征融合网络的图像异常检测算法。通过使用融合了异常先验知识的伪异常数据生成算法,对训练集进行了异常数据扩充,将异... 图像异常检测旨在识别并定位图像中的异常区域,针对现有算法中不同层次特征信息利用不充分的问题,提出了基于多层次特征融合网络的图像异常检测算法。通过使用融合了异常先验知识的伪异常数据生成算法,对训练集进行了异常数据扩充,将异常检测任务转化为监督学习任务;构建了多层次特征融合网络,将神经网络中不同层次特征进行融合,丰富了特征中的低层纹理信息和高层语义信息,使得用于异常检测的特征更具区分性;训练时,设计了分数约束损失和一致性约束损失,并结合特征约束损失对整个网络模型进行训练。实验结果表明,MVTec数据集上图像级检测接收机工作特性曲线下面积(area under the receiver operating characteristic, AUROC)平均值为98.7%,像素级定位AUROC平均值为97.9%,每区域重叠率平均值为94.2%,均高于现有的异常检测算法。 展开更多
关键词 图像异常检测 伪异常 多层次特征融合 一致性约束
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基于核主成分分析的半监督日志异常检测模型 被引量:3
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作者 顾兆军 叶经纬 +2 位作者 刘春波 张智凯 王志 《江苏大学学报(自然科学版)》 CAS 北大核心 2025年第1期64-72,97,共10页
对于具有“组异常”和“局部异常”分布特点的系统日志数据,传统的ADOA(anomaly detection with partially observed anomalies)半监督日志异常检测方法存在为无标签数据生成的伪标签准确性不佳的问题.针对此问题,提出一种改进的半监督... 对于具有“组异常”和“局部异常”分布特点的系统日志数据,传统的ADOA(anomaly detection with partially observed anomalies)半监督日志异常检测方法存在为无标签数据生成的伪标签准确性不佳的问题.针对此问题,提出一种改进的半监督日志异常检测模型.对已知异常样本采用k均值聚类,采用核主成分分析计算无标签样本的重构误差;运用重构误差和异常样本相似分计算出样本的综合异常分,作为其伪标签;依据伪标签计算LightGBM分类器的样本权重,训练异常检测模型.通过参数试验探究了训练集样本比例变化对模型性能的影响.在HDFS和BGL这2个公开数据集上进行试验,结果表明该模型能够提高伪标签的准确性,相较于DeepLog、LogAnomaly、LogCluster、PCA和PLELog等已有模型,精确率和F 1分数均有提升.与传统的ADOA异常检测方法相比,该模型F 1分数在2类数据集上分别提高了0.084和0.085. 展开更多
关键词 系统日志 日志异常检测 组异常 局部异常 半监督 重构误差 核主成分分析 伪标签
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