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Ingredients-based Methodology and Fuzzy Logic Combined Short-Duration Heavy Rainfall Short-Range Forecasting:An Improved Scheme
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作者 TIAN Fu-you XIA Kun +2 位作者 SUN Jian-hua ZHENG Yong-guang HUA Shan 《Journal of Tropical Meteorology》 SCIE 2024年第3期241-256,共16页
Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the mos... Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the most common convective weather phenomena that can cause severe damage.Short-range forecasting of SHR is an important part of operational severe weather prediction.In the present study,an improved objective SHR forecasting scheme was developed by adopting the ingredients-based methodology and using the fuzzy logic approach.The 1.0°×1.0°National Centers for Environmental Prediction(NCEP)final analysis data and the ordinary rainfall(0.1-19.9 mm h-1)and SHR observational data from 411 stations were used in the improved scheme.The best lifted index,the total precipitable water,the 925 hPa specific humidity(Q 925),and the 925 hPa divergence(DIV 925)were selected as predictors based on objective analysis.Continuously distributed membership functions of predictors were obtained based on relative frequency analysis.The weights of predictors were also objectively determined.Experiments with a typhoon SHR case and a spring SHR case show that the main possible areas could be captured by the improved scheme.Verification of SHR forecasts within 96 hours with NCEP global forecasts 1.0°×1.0°data initiated at 08:00 Beijing Time during the warm seasons in 2015 show the results were improved from both deterministic and probabilistic perspectives.This study provides an objectively feasible choice for short-range guidance forecasts of SHR.The scheme can be applied to other convective phenomena. 展开更多
关键词 ingredients-based methodology fuzzy logic approach probability of short-duration heavy rainfall(SHR) improved forecasting scheme objectively obtained membership functions
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Storm分布式计算框架下基于知识图谱的快速学习资源推荐 被引量:2
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作者 刘莹 杨淑萍 张治国 《南京邮电大学学报(自然科学版)》 北大核心 2024年第3期93-99,共7页
针对在线学习资源推荐存在精度较低或实时性较差的问题,采用知识图谱进行用户及资源的知识表示,并采用长短时间记忆网络对用户资源特征差进行优化,从而将与用户特征差最小的资源推送给用户。首先,在获得在线学习记录样本后,利用知识图... 针对在线学习资源推荐存在精度较低或实时性较差的问题,采用知识图谱进行用户及资源的知识表示,并采用长短时间记忆网络对用户资源特征差进行优化,从而将与用户特征差最小的资源推送给用户。首先,在获得在线学习记录样本后,利用知识图谱进行实体特征关系的知识表示,并借助Storm分布式框架生成知识图谱中头尾实体及关系特征向量。接着,建立用户-资源实体的最小特征差目标函数,并采用长短时间记忆网络对最小特征差目标函数进行优化。最后,通过Storm分布式平台进行长短时间记忆网络的参数求解,从而快速生成稳定的相关资源推荐模型。实验结果表明,在Storm分布式框架下采用知识图谱和长短时间记忆网络实现在线资源推荐,可获得较高准确率及运行效率,在应对大规模资源的实时推荐方面具有较强的适应度。 展开更多
关键词 资源推荐 知识图谱 storm框架 长短时间记忆 TransD模型
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Machine Learning Analysis of Impact of Western US Fires on Central US Hailstorms 被引量:1
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作者 Xinming LIN Jiwen FAN +1 位作者 Yuwei ZHANG ZJason HOU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第7期1450-1462,共13页
Fires,including wildfires,harm air quality and essential public services like transportation,communication,and utilities.These fires can also influence atmospheric conditions,including temperature and aerosols,potenti... Fires,including wildfires,harm air quality and essential public services like transportation,communication,and utilities.These fires can also influence atmospheric conditions,including temperature and aerosols,potentially affecting severe convective storms.Here,we investigate the remote impacts of fires in the western United States(WUS)on the occurrence of large hail(size:≥2.54 cm)in the central US(CUS)over the 20-year period of 2001–20 using the machine learning(ML),Random Forest(RF),and Extreme Gradient Boosting(XGB)methods.The developed RF and XGB models demonstrate high accuracy(>90%)and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide,particularly in four states(Wyoming,South Dakota,Nebraska,and Kansas).The key contributing variables identified from both ML models include the meteorological variables in the fire region(temperature and moisture),the westerly wind over the plume transport path,and the fire features(i.e.,the maximum fire power and burned area).The results confirm a linkage between WUS fires and severe weather in the CUS,corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model. 展开更多
关键词 WILDFIRE severe convective storm HAILstorm machine learning
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Thermosphere joint observations by TM-1 constellations and Swarm-B during the April 2023 geomagnetic storm
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作者 YongPing Li YueQiang Sun +9 位作者 XianGuo Zhang JiangZhao Ai XiaoLiang Zheng Jia Li YuJie Wang BiBo Guo Feng Yan ShiLong Wei XinChun Tang YuanYuan Cao 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期307-316,共10页
The response of thermosphere density to geomagnetic storms is a complicated physical process.Multi-satellite joint observations at the same altitude but different local times(LTs)are important for understanding this p... The response of thermosphere density to geomagnetic storms is a complicated physical process.Multi-satellite joint observations at the same altitude but different local times(LTs)are important for understanding this process;however,until now such studies have hardly been done.In this report,we analyze in detail the thermosphere mass density response at 510 km during the April 23−24,2023 geomagnetic storm using data derived from the TM-1(TianMu-1)satellite constellation and Swarm-B satellites.The observations show that there were significant LT differences in the hemispheric asymmetry of the thermosphere mass density during the geomagnetic storm.Densities observed by satellite TM02 at nearly 11.3 and 23.3 LTs were larger in the northern hemisphere than in the southern.The TM04 dayside density observations appear to be almost symmetrical with respect to the equator,though southern hemisphere densities on the nightside were higher.Swarm-B data exhibit near-symmetry between the hemispheres.In addition,the mass density ratio results show that TM04 nightside observations,TM02 data,and Swarm-B data all clearly show stronger effects in the southern hemisphere,except for TM04 on the dayside,which suggest hemispheric near-symmetry.The South-North density enhancement differences in TM02 and TM04 on dayside can reach 130%,and Swarm-B data even achieve 180%difference.From the observations of all three satellites,large-scale traveling atmospheric disturbances(TADs)first appear at high latitudes and propagate to low latitudes,thereby disturbing the atmosphere above the equator and even into the opposite hemisphere.NRLMSISE00 model simulations were also performed on this geomagnetic storm.TADs are absent in the NRLMSISE00 simulations.The satellite data suggest that NRLMSISE00 significantly underestimates the magnitude of the density response of the thermosphere during geomagnetic storms,especially at high latitudes in both hemispheres.Therefore,use of the density simulation of NRLMSISE00 may lead to large errors in satellite drag calculations and orbit predictions.We suggest that the high temporal and spatial resolution of direct density observations by the TM-1 constellation satellites can provide an autonomous and reliable basis for correction and improvement of atmospheric models. 展开更多
关键词 TM-1 constellation Swarm-B joint observations geomagnetic storm Local Times
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Trend of Storm Surge Induced by Typical Landfall Super Typhoons During 1975–2021 in the Eastern China Sea
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作者 LUO Feng WANG Yi +3 位作者 TAO Aifeng SHI Jian WANG Yongzhi ZHANG Chi 《Journal of Ocean University of China》 CAS CSCD 2024年第2期277-286,共10页
Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast ... Climate change affects the activity of global and regional tropical cyclones(TCs).Among all TCs,typical super typhoons(STYs)are particularly devastating because they maintain their intensity when landing on the coast and thus cause casualties,economic losses,and environmental damage.Using a 3D tidal model,we reconstructed the typhoon(TY)wind field to simulate the storm surge induced by typical STYs.The TY activity was then analyzed using historical data.Results showed a downtrend of varying degrees in the annual frequency of STYs and TCs in the Western North Pacific(WNP)Basin,with a significant trend change observed for TCs from 1949 to 2021.A large difference in the interannual change in frequency was found between STYs and TCs in the WNP and Eastern China Sea(ECS).Along the coast of EC,the frequency of landfall TCs showed a weak downtrend,and the typical STYs showed reverse micro growth with peak activity in August.Zhejiang,Fujian,and Taiwan were highly vulnerable to the frontal hits of typical STYs.Affected by climate change,the average lifetime maximum intensity(LMI)locations and landfall locations of typical STYs in the ECS basin showed a significant poleward migration trend.In addition,the annual average LMI and accumulated cyclone energy showed an uptrend,indicating the increasing severity of the disaster risk.Affected by the typical STY activity in the ECS,the maximum storm surge area also showed poleward migration,and the coast of North China faced potential growth in high storm surge risks. 展开更多
关键词 storm surge super typhoons tropical cyclones eastern China Sea poleward migration
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Recent geomagnetic storms observed by Macao Science Satellite-1
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作者 Qing Yan HongBo Yao 《Earth and Planetary Physics》 EI CAS CSCD 2024年第4期565-569,共5页
Geomagnetic storms are rapid disturbances of the Earth’s magnetosphere.They are related to many geophysical phenomena and have large influences on human activities.Observing and studying geomagnetic storms is thus of... Geomagnetic storms are rapid disturbances of the Earth’s magnetosphere.They are related to many geophysical phenomena and have large influences on human activities.Observing and studying geomagnetic storms is thus of great significance to both scientific research and geomagnetic hazards prevention.The Macao Science Satellite-1(MSS-1)project includes two high-precision Chinese geomagnetic satellites successfully launched on May 21,2023.The main purpose of MSS-1 is to accurately measure the Earth’s magnetic field.Here,we analyze early MSS-1 geomagnetic field measurements and report observations of two recent geomagnetic storms that occurred on March 24,2024 and May 11,2024.We also calculate the related geoelectric fields as an initial step towards a quantitative assessment of geomagnetic hazards. 展开更多
关键词 Macao Science Satellite-1 geomagnetic storms satellite magnetics electromagnetic induction geoelectric fields
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A typhoon-induced storm surge numerical model with GPU acceleration based on an unstructured spherical centroidal Voronoi tessellation grid
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作者 Yuanyong Gao Fujiang Yu +2 位作者 Cifu Fu Jianxi Dong Qiuxing Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2024年第3期40-47,共8页
Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal areas.Accurate and timely issuance of storm surge warnings to take appropriate countermeasures is an important me... Storm surge is often the marine disaster that poses the greatest threat to life and property in coastal areas.Accurate and timely issuance of storm surge warnings to take appropriate countermeasures is an important means to reduce storm surge-related losses.Storm surge numerical models are important for storm surge forecasting.To further improve the performance of the storm surge forecast models,we developed a numerical storm surge forecast model based on an unstructured spherical centroidal Voronoi tessellation(SCVT)grid.The model is based on shallow water equations in vector-invariant form,and is discretized by Arakawa C grid.The SCVT grid can not only better describe the coastline information but also avoid rigid transitions,and it has a better global consistency by generating high-resolution grids in the key areas through transition refinement.In addition,the simulation speed of the model is accelerated by using the openACC-based GPU acceleration technology to meet the timeliness requirements of operational ensemble forecast.It only takes 37 s to simulate a day in the coastal waters of China.The newly developed storm surge model was applied to simulate typhoon-induced storm surges in the coastal waters of China.The hindcast experiments on the selected representative typhoon-induced storm surge processes indicate that the model can reasonably simulate the distribution characteristics of storm surges.The simulated maximum storm surges and their occurrence times are consistent with the observed data at the representative tide gauge stations,and the mean absolute errors are 3.5 cm and 0.6 h respectively,showing high accuracy and application prospects. 展开更多
关键词 typhoon-induced storm surge numerical model GPU acceleration unstructured grid spherical centroidal Voronoi tessellation(SCVT)
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The dawn−dusk asymmetry in mesosphere and lower thermosphere temperature disturbances during geomagnetic storms at high latitude
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作者 GuanChun Wei JianYong Lu +2 位作者 Fen Tang JingYuan Li Meng Sun 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期356-367,共12页
Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mes... Utilizing observations by the Sounding of the Atmosphere using Broadband Emission Radiometry(SABER)instrument,we quantitatively assessed the dawn-dusk asymmetry in temperature disturbances within the high-latitude mesosphere and lower thermosphere(MLT)during the main phase of geomagnetic storms in this study.An analysis of five geomagnetic superstorm events indicated that during the main phase,negative temperature disturbances were more prevalent on the dawn side than on the dusk side in the high-latitude MLT region.Results of a statistical analysis of 54 geomagnetic storm events also revealed a notable disparity in temperature disturbances between the dawn and dusk sides.At high latitudes,38.2%of the observational points on the dawn side exhibited negative temperature disturbances(less than−5 K),whereas on the dusk side,this percentage was only 29.5%.In contrast,at mid-latitudes,these proportions were 34.1%and 36.5%,respectively,showing no significant difference.We also conducted a statistical analysis of temperature disturbances at different altitudes,which revealed an increase in the proportion of warming disturbances with altitude.Conversely,the proportion of cooling disturbances initially rose with altitude,reaching a peak around 105 km,and subsequently decreased.These temperature disturbance differences could be explained by the day-night asymmetry in vertical wind disturbances during storm conditions. 展开更多
关键词 DAWN dusk asymmetry SABER(Sounding of the Atmosphere using Broadband Emission Radiometry) geomagnetic storms mesosphere and lower thermosphere
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基于Storm云平台的电力设备并行故障诊断方法
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作者 刘少伟 《电工技术》 2024年第14期132-135,共4页
为了实现电力行业多源数据的监测诊断,应对电力系统的实时处理需求,引入Storm分布式实时计算平台对数据进行处理。在此平台上部署基于混合聚类的流数据处理模型,实现数据流的故障诊断。通过将减法聚类算法和K-means算法结合实现流式数... 为了实现电力行业多源数据的监测诊断,应对电力系统的实时处理需求,引入Storm分布式实时计算平台对数据进行处理。在此平台上部署基于混合聚类的流数据处理模型,实现数据流的故障诊断。通过将减法聚类算法和K-means算法结合实现流式数据的故障检测。减法聚类获取较优的聚类中心,而K-means算法根据此聚类中心计算出较好的分类结果。测试集群和单机的数据处理量的结果表明在集群环境下合理设置组件并行度可以提高流计算时效性和吞吐量。 展开更多
关键词 故障诊断 storm云平台 减法聚类 K-MEANS
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Risk assessment of coastal flooding disaster by storm surge based on Elevation-Area method and hydrodynamic models:Taking Bohai Bay as an example
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作者 Fu Wang Xue-zheng Liu +3 位作者 Yong Li Heng Yu Ming-zheng Wen Yun-zhuang Hu 《China Geology》 CAS CSCD 2024年第3期494-504,共11页
The future inundation by storm surge on coastal areas are currently ill-defined.With increasing global sealevel due to climate change,the coastal flooding by storm surge is more and more frequently,especially in coast... The future inundation by storm surge on coastal areas are currently ill-defined.With increasing global sealevel due to climate change,the coastal flooding by storm surge is more and more frequently,especially in coastal lowland with land subsidence.Therefore,the risk assessment of such inundation for these areas is of great significance for the sustainable socio-economic development.In this paper,the authors use Elevation-Area method and Regional Ocean Model System(ROMS)model to assess the risk of the inundation of Bohai Bay by storm surge.The simulation results of Elevation-Area method show that either a 50-year or 100-year storm surge can inundate coastal areas exceeding 8000 km^(2);the numerical simulation results based on hydrodynamics,considering ground friction and duration of the storm surge high water,show that a 50-year or 100-year storm surge can only inundate an area of over 2000 km^(2),which is far less than 8000 km^(2);while,when taking into account the land subsidence and sea level rise,the very inundation range will rapidly increase by 2050 and 2100.The storm surge will greatly impact the coastal area within about 10-30 km of the Bohai Bay,in where almost all major coastal projects are located.The prompt response to flood disaster due to storm surge is urgently needed,for which five suggestions have been proposed based on the geological background of Bohai Bay.This study may offer insight into the development of the response and adaptive plans for flooding disasters caused by storm surge. 展开更多
关键词 storm surge ROMS Elevation-Area method Numerical simulation Land subsidence Flooding disaster Sea level rise Marine geological survey engineering Geological disaster survey engineering Bohai Bay
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Anta Storm Mecha Jacket:Pioneering domestic waterproof tech
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《China Textile》 2024年第2期13-13,共1页
The Anta Storm Mecha Jacket is a rainproof and comfortable jacket launched by Anta and Donghua University.It is equipped with China's first self-developed high-performance waterproof and breathable material-Aerove... The Anta Storm Mecha Jacket is a rainproof and comfortable jacket launched by Anta and Donghua University.It is equipped with China's first self-developed high-performance waterproof and breathable material-Aerovent.This jacket not only has excellent waterproof performance,but also achieves a soft,breathable and comfortable wearing experience.After testing by an authoritative third-party organization,its waterproof and breathable performance is comparable to international brands. 展开更多
关键词 storm PIONEER has
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基于Storm的可扩展的分布式网络爬虫系统设计研究
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作者 池国俊 《电脑知识与技术》 2024年第20期89-91,共3页
为提高分布式网络爬虫的速度和性能,文章应用Storm云平台,提出了分布式网络爬虫系统的设计方案。首先,针对传统单机网络爬虫技术过于落后,无法满足现代化日益增长的数据抓取使用需求等问题,严格遵循系统设计原则,运用Storm云平台等技术... 为提高分布式网络爬虫的速度和性能,文章应用Storm云平台,提出了分布式网络爬虫系统的设计方案。首先,针对传统单机网络爬虫技术过于落后,无法满足现代化日益增长的数据抓取使用需求等问题,严格遵循系统设计原则,运用Storm云平台等技术,完成了系统框架设计、系统数据库以及种子URL文档、模拟登录、URL优化链接、网页下载等模块的设计,确保系统功能实现效果。最后,对系统设计方案的执行效果进行了测试。结果表明:文章提出的系统设计方案具有较高的可靠性和可行性,各个功能模块运行良好,其准确率达到百分之百,使得本系统具有可靠性高、稳定性强、数据处理效率高等特点,完全符合预期的设计标准和要求。 展开更多
关键词 storm 可扩展 分布式 网络爬虫 系统设计
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基于Storm的涉油气犯罪实时检测系统的研究与应用
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作者 张丽华 李宏博 +4 位作者 王健 张伟民 李欣欣 李娟 邵国强 《智能计算机与应用》 2023年第7期123-127,共5页
针对重点涉油气企业犯罪人群分布特性,构建一个分析模型至关重要。通过对比分析、经验总结及仿真实验等研究方法来全局掌握涉犯罪人群热度指数、分布密度等因素,并借助服务器和Storm等相关技术搭建数据处理平台,再基于Logstash构建热力... 针对重点涉油气企业犯罪人群分布特性,构建一个分析模型至关重要。通过对比分析、经验总结及仿真实验等研究方法来全局掌握涉犯罪人群热度指数、分布密度等因素,并借助服务器和Storm等相关技术搭建数据处理平台,再基于Logstash构建热力图,对数据具体位置结果进行判定,实现最终的设计及体系架构。经过本次构建研究,可以更精准地监测犯罪者,预判涉油气行业,尤其是在未来涉油气犯罪的总体趋势,充分发挥了数据处理的实时性,为涉油气企业资源犯罪的防控提供了相应的参考依据与保障。 展开更多
关键词 大数据处理 storm技术 Logstash 热力图 实时检测
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Short-duration transient visual evoked potentials and color reflectivity discretization analysis in glaucoma patients and suspects 被引量:1
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作者 Michael Waisbourd Rebekah H.Gensure +7 位作者 Ardalan Aminlari Sonya B.Shah Nitasha Khanna Neil Sood Jeanne Molineaux Alberto Gonzalez Jonathan S.Myers L.Jay Katz 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2017年第2期254-261,共8页
AIM: To evaluate the use of short-duration transient visual evoked potentials(VEP) and color reflectivity discretization analysis(CORDA) in glaucomatous eyes,eyes suspected of having glaucoma,and healthy eyes.MET... AIM: To evaluate the use of short-duration transient visual evoked potentials(VEP) and color reflectivity discretization analysis(CORDA) in glaucomatous eyes,eyes suspected of having glaucoma,and healthy eyes.METHODS: The study included 136 eyes from 136 subjects: 49 eyes with glaucoma,45 glaucoma suspect eyes,and 42 healthy eyes.Subjects underwent Humphrey visual field(VF) testing,VEP testing,as well as peripapillary retinal nerve fiber layer optical coherence tomography imaging studies with post-acquisition CORDA applied.Statistical analysis was performed using means and ranges,ANOVA,post-hoc comparisons using Turkey's adjustment,Fisher's Exact test,area under the curve,and Spearman correlation coefficients.RESULTS: Parameters from VEP and CORDA correlated significantly with VF mean deviation(MD)(P〈0.05).In distinguishing glaucomatous eyes from controls,VEP demonstrated area under the curve(AUC) values of 0.64-0.75 for amplitude and 0.67-0.81 for latency.The CORDA HR1 parameter was highly discriminative for glaucomatous eyes vs controls(AUC=0.94).CONCLUSION: Significant correlations are found between MD and parameters of short-duration transient VEP and CORDA,diagnostic modalities which warrant further consideration in identifying glaucoma characteristics. 展开更多
关键词 short-duration transient visual evoked potentials optical coherence tomography color reflectivity discretization analysis GLAUCOMA
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面向Storm的自适应粒度监控组件设计与实现
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作者 李丽娜 连鹏 +2 位作者 王子昂 靳德政 李念峰 《计算机工程与设计》 北大核心 2023年第12期3809-3818,共10页
针对Storm系统提供的监控信息不全面且无法直接获取、监控粒度固定的问题,设计和实现一个自适应粒度的可视化监控组件。采用自适应粒度监控算法提供不同粒度的控制数据,结合网络文件系统、数据库和腾讯云图技术,从Storm UI和日志文件中... 针对Storm系统提供的监控信息不全面且无法直接获取、监控粒度固定的问题,设计和实现一个自适应粒度的可视化监控组件。采用自适应粒度监控算法提供不同粒度的控制数据,结合网络文件系统、数据库和腾讯云图技术,从Storm UI和日志文件中获取、存储和统计拓扑运行状态信息,以图表的形式在网页中动态地显示监控数据。测试结果表明,监控组件能够准确地追踪集群和拓扑状态变化,从多拓扑和单拓扑的角度可视化监控数据,提高监控的灵活性、多样性和直观性,支持系统资源管理和调度策略调试。 展开更多
关键词 流式计算 监控组件 自适应粒度 资源调度 storm系统 storm UI 腾讯云图
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Ultrasound-guided stellate ganglion blockade: an appealing tactic for cardiac electrical storm 被引量:1
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作者 Zi-Hao LAI Li-Hui ZHENG Yan YAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2023年第5期376-382,共7页
Ventricular arrhythmia(VA)is a life-threatening cardiac emergency.When VA occurs three times or more within 24 h and interventions are required,it is defined as an electrical storm(ES)characterized by refractoriness a... Ventricular arrhythmia(VA)is a life-threatening cardiac emergency.When VA occurs three times or more within 24 h and interventions are required,it is defined as an electrical storm(ES)characterized by refractoriness and recurrence.[1]For patients with implantable cardioverter defibrillator(ICD),the notion is redefined as no fewer than three appropriate and separate(at least 5 min for each interval)ICD interventions given within 24 h. 展开更多
关键词 CARDIAC storm ELECTRICAL
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Dynamic geomorphology and storm response characteristics of the promontory-straight beach-a case of Gulei Beach, Fujian 被引量:1
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作者 Chao Cao Zijian Mao +5 位作者 Feng Cai Hongshuai Qi Jianhui Liu Gang Lei Shaohua Zhao Gen Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第7期64-78,共15页
As one of the main areas of tropical storm action in the northwestern Pacific Ocean,South China experiences several typhoons each year,and coastal erosion is a problem,making the area a natural testing ground for stud... As one of the main areas of tropical storm action in the northwestern Pacific Ocean,South China experiences several typhoons each year,and coastal erosion is a problem,making the area a natural testing ground for studying the dynamic geomorphological processes and storm response of promontory-straight coasts.This study is based on three years of topographic data and remote sensing imagery of Gulei Beach and uses topographic profile morphology,single width erosion-accretion and mean change,combined with the Coastsat model to quantify the seasonal and interannual variability and storm response of the beach and to explain the evolution of shoreline change and beach dynamics geomorphology in the last decade.Gulei Beach has been in a state of overall erosion and local accretion for a long time,with relatively obvious cyclical changes;seasonal changes are also obvious,which are mainly characterized by summer accretion and winter erosion,with accretion at the top of the bay and accretion and erosion on the north and south sides of the bay corner,respectively;the seasonal erosion-accretion volume of the beach profile ranges from-80 m3/m to 95.52 m3/m,and the interannual erosion-accretion volume ranges from-69.09 m3/m to 87.31 m3/m.The response of beaches to typhoons with different paths varies greatly depending on the length,slope,orientation and scale of beach development.The large and gently developing Futou beach is less responsive to storms,while the less developed headlands in the southern Gulei Peninsula are more susceptible to disturbance by external factors and respond more strongly to typhoons.Storm distance is more influential than storm intensity.Under the influence of human activities,obvious erosion hotspots develop during normal weather,but storm processes produce redistribution of beach material patterns,and erosion hotspots disappear after storms.The results of this study enrich the theory of beach dynamics geomorphology and provide technical support for disaster prevention and mitigation,as well as ecological restoration of coastal zones. 展开更多
关键词 promontory-straight beach dynamic geomorphology storm response Gulei Peninsula
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Responses of the field-aligned currents in the plasma sheet boundary layer to a geomagnetic storm 被引量:1
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作者 YuanQiang Chen MingYu Wu +3 位作者 YangJun Chen SuDong Xiao GuoQiang Wang TieLong Zhang 《Earth and Planetary Physics》 CAS CSCD 2023年第5期558-564,共7页
Geomagnetic storms can result in large magnetic field disturbances and intense currents in the magnetosphere and even on the ground.As an important medium of momentum and energy transport among the solar wind,magnetos... Geomagnetic storms can result in large magnetic field disturbances and intense currents in the magnetosphere and even on the ground.As an important medium of momentum and energy transport among the solar wind,magnetosphere,and ionosphere,field-aligned currents(FACs)can also be strengthened in storm times.This study shows the responses of FACs in the plasma sheet boundary layer(PSBL)observed by the Magnetospheric Multiscale(MMS)spacecraft in different phases of a large storm that lasted from May 27,2017,to May 29,2017.Most of the FACs were carried by electrons,and several FACs in the storm time also contained sufficient ion FACs.The FAC magnitudes were larger in the storm than in the quiet period,and those in the main phase were the strongest.In this case,the direction of the FACs in the main phase showed no preference for tailward or earthward,whereas the direction of the FACs in the recovery phase was mostly tailward.The results suggest that the FACs in the PSBL are closely related to the storm and could be driven by activities in the tail region,where the energy transported from the solar wind to the magnetosphere is stored and released as the storm is evolving.Thus,the FACs are an important medium of energy transport between the tail and the ionosphere,and the PSBL is a significant magnetosphere–ionosphere coupling region in the nightside. 展开更多
关键词 field-aligned currents plasma sheet boundary layer geomagnetic storm
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Response of the North Pacific Storm Track Activity in the Cold Season to Multi-scale Oceanic Variations of Kuroshio Extension System: A Statistical Assessment 被引量:1
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作者 Peilong YU Minghao YANG +3 位作者 Chao ZHANG Yi LI Lifeng ZHANG Shiyao CHEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2023年第3期514-530,共17页
In this paper,a statistical method called Generalized Equilibrium Feedback Analysis(GEFA)is used to investigate the responses of the North Pacific Storm Track(NPST)in the cold season to the multi-scale oceanic variati... In this paper,a statistical method called Generalized Equilibrium Feedback Analysis(GEFA)is used to investigate the responses of the North Pacific Storm Track(NPST)in the cold season to the multi-scale oceanic variations of the Kuroshio Extension(KE)system,including its large-scale variation,oceanic front meridional shift,and mesoscale eddy activity.Results show that in the cold season from the lower to the upper troposphere,the KE large-scale variation significantly weakens the storm track activity over the central North Pacific south of 30°N.The northward shift of the KE front significantly strengthens the storm track activity over the western and central North Pacific south of 40°N,resulting in a southward shift of the NPST.In contrast,the NPST response to KE mesoscale eddy activity is not so significant and relatively shallow,which only shows some significant positive signals near the dateline in the lower and middle troposphere.Furthermore,it is found that baroclinicity and baroclinic energy conversion play an important role in the formation of the NPST response to the KE multi-scale oceanic variations. 展开更多
关键词 generalized equilibrium feedback analysis Kuroshio Extension multi-scale oceanic variations North Pacific storm track
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Analysis of Anomalous Enhancement in TEC and Electron Density in the China Region Prior to the 17 March 2015 Geomagnetic Storm Based on Ground and Space Observations 被引量:1
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作者 Xiaoyun CHENG Dongjie YUE +2 位作者 Changzhi ZHAI Yutian CHEN Xunzhe YIN 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第2期40-50,共11页
Total Electron Content(TEC)and electron density enhancement were observed on the day before 17 March 2015 great storm in the China Region.Observations from ground-and space-based instruments are used to investigate th... Total Electron Content(TEC)and electron density enhancement were observed on the day before 17 March 2015 great storm in the China Region.Observations from ground-and space-based instruments are used to investigate the temporal and spatial evolution of the pre-storm enhancement.TEC enhancement was observed from 24°N to 30°N after 10:00 UT at 105°E,110°E and 115°E longitudes on March 16.The maximum magnitude of TEC enhancement was more than 10 TECU and the maximal relative TEC enhancement exceeded 30%.Compared with geomagnetic quiet days,the electron density of Equatorial Ionization Anomaly(EIA)northern peak from Swarm A/C satellites on March 16 was larger and at higher latitudes.NmF2 enhanced during 11:30—21:00 UT at Shaoyang Station and increased by 200%at~16:00 UT.However,TEC and electron density enhancement were not accompanied by a significant change of hmF2.Most research has excluded some potential mechanisms as the main driving factors for storm-time density enhancements by establishing observational constraints.In this paper,we observed pre-storm enhancement in electron density at different altitudes and Equatorial Electrojet(EEJ)strength results derived from ground magnetometers observations suggest an enhanced eastward electric field from the E region probably played a significant role in this event. 展开更多
关键词 Equatorial Ionization Anomaly(EIA) electron density geomagnetic storm Total Electron Content(TEC) zonal electric field
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