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Comparative case study of two methods to assess the eruptive potential of selected active regions

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Research in Astronomy and Astrophysics 2021年第12期21卷 471-487页

作者： Francesca Zuccarello Ilaria Ermolli marianna b.korsós Fabrizio Giorgi salvo L.Guglielmino Robertus Erdélyi Paolo Romano Dipartimento di Fisica e Astronomia"Ettore Majorana" Universitàdi CataniaVia S.Sofia 78195123 CataniaItaly INAF Osservatorio Astrofisico di Catania Via S.Sofia 781-95123 CataniaItaly INAF Osservatorio Astronomico di Roma Via Frascati 331-00078 Monte Porzio CatoneItaly Department of Physics Aberystwyth UniversityCeredigionCymruSY233BZUK Department of Astronomy E?tv?s Loránd UniversityPazmany P.setany 1/ABudapestH-l 117Hungary solar Physics&space Plasma Research Center(sP2RC) School of Mathematics and StatisticsUniversity of SheffieldHicks BuildingHounsfield RoadS37RHUK Gyula bay Zoltán solar Observatory(GsO) Hungarian Solar Physics Foundation(HSPF)etofi ter 3.GyulaH-5700Hungary

solar eruptive events,like flares and coronal mass ejections,are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in the kinetic energy of *** energetic phenomena can have important effects on the space weather conditions and therefore it is necessary to understand their origin,in particular,what is the eruptive potential of an active region(AR).In these case studies,we compare two distinct methods that were used in previous works to investigate the variations of some characteristic physical parameters during the pre-flare states of flaring *** methods consider:i)the magnetic flux evolution and magnetic helicity accumulation,and ii)the fractal and multi-fractal properties of flux concentrations in *** comparative analysis is based on time series of photospheric data obtained by the solar Dynamics Observatory between March 2011 and June *** selected two distinct samples of ARs:one is distinguished by the occurrence of more energetic M-and X-class flare events,that may have a rapid effect on not just the near-Earth space,but also on the terrestrial environment;the second is characterized by no-flares or having just a few C-and b-class *** found that the two tested methods complement each other in their ability to assess the eruptive potentials of ARs and could be employed to identify ARs prone to flaring *** on the presented case study,we suggest that using a combination of different methods may aid to identify more reliably the eruptive potentials of ARs and help to better understand the pre-flare states.

关键词： sun:magnetic fields sun:photosphere sun:sunspots sun:flares sun:activity

基于机器学习方法的短期太阳爆发活动预报模型综述

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中国科学：地球科学 2024年第12期54卷 3766-3805页

作者：黄鑫赵忠瑞钟昱丰徐龙 marianna b.korsOs R.ERDELYI 宁波大学信息科学与工程学院宁波315211 中国科学院空间天气学国家重点实验室国家空间科学中心北京100190 中国科学院大学天文与空间科学学院北京100049 北京元胞探索科技中心北京100190 Dipartimento di Fisica e Astronomia“Ettore Majorana” Universitàdi CataniaCatania I 95123Italy Department of Astronomy Eotvos Loránd UniversityBudapest H-1112Hungary Hungarian solar Physics Foundation Gyula H-5700Hungary solar Physics&space Plasma Research Center(sP2RC) School of Mathematics and StatisticsUniversity of SheffieldSheffield S37RHUK

太阳爆发活动主要包括太阳耀斑、日冕物质抛射(coronal mass ejections,CME)和太阳质子事件(solar proton events,sPE),太阳爆发活动对空间天气和高技术领域有重要影响.太阳爆发活动短期预报是空间天气预报中一个活跃的研究领域.目前,... 详细信息

太阳爆发活动主要包括太阳耀斑、日冕物质抛射(coronal mass ejections,CME)和太阳质子事件(solar proton events,sPE),太阳爆发活动对空间天气和高技术领域有重要影响.太阳爆发活动短期预报是空间天气预报中一个活跃的研究领域.目前,数值的、统计的和机器学习的方法被用来建立太阳爆发活动预报模型.随着天基和地基观测设备的发展,积累了大量的太阳观测数据,数据驱动的太阳爆发活动预报模型取得了重大进展.本文介绍了机器学习算法在太阳爆发活动预报中的应用,总结了预报建模过程,概述了太阳爆发活动预报模型的进展,并展望了未来可能的研究方向.

关键词：太阳耀斑日冕物质抛射太阳质子事件机器学习预报模型

老年人群中QTc间期延长与心脏性猝死风险之间的关系

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世界核心医学期刊文摘（心脏病学分册） 2006年第5期2卷 47-48页

作者： straus s.M.J.M kors J.A De bruin M.L. b.H.Ch. stricker 王亭忠 Department of Epidemiology and biostatistics Erasmus Medical Center P.O. Box 1738 3000 DR Rotterdam NetherlandsDr.

ObJECTIVEs: This study sought to investigate whether prolongation of the heart rate-corrected QT(QTc) interval is a risk factor for sudden cardiac death in the general population. bACKGROUND: In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death. METHODs: This study was conducted as part of the Rotterdam study, a prospective population- based cohort study that comprises 3,105 men and 4,878 women aged 55 years and older. The QTc interval on the electrocardiogram was determined during the baseline visit(1990 to 1993) and the first follow-up examination(1993 to 1995). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis. REsULTs: During an average follow-up period of 6.7 years(standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval(>450 ms in men, >470 ms in women) was associated with a threefold increased risk of sudden cardiac death(hazard ratio, 2.5; 95% confidence interval, 1.3 to 4.7), after adjustment for age, gender, body mass index, hypertension, cholesterol/high-density lipoprotein ratio, diabetes mellitus, myocardial infarction, heart failure, and heart rate. In patients with an age below the median of 68 years, the corresponding relative risk was 8.0(95% confidence interval 2.1 to 31.3). CONCLUsIONs: Abnormal QTc prolongation on the electrocardiogram should be viewed as an independent risk factor for sudden cardiac death.

关键词： QTc间期延长心脏性猝死老年人群风险分析室性心律失常疾病死亡危险因素心率校正普通人群发达国家