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PROBABILITY OF RANDOM EVENTS OF INSPECTION AND REPAIR AND MAINTAINING RELIABILITY OF STRUCTURES
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作者 郭书祥 吕震宙 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2000年第3期311-320,共10页
Reliability analysis of the inspected and repaired structure requires dealing with a large number of complex random events. Considering many kinds of random factors, a probability of these random events existing possi... Reliability analysis of the inspected and repaired structure requires dealing with a large number of complex random events. Considering many kinds of random factors, a probability of these random events existing possibly in the inspection and repair process and reliability analysis methodologies are proposed. A systematic dynamic reliability model is given for structures in service under the scheduled inspection and repair. 展开更多
关键词 fatigue crack growth random events of inspection and repair maintaining RELIABILITY
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Studies of reasonability of computing return period of storm surge based on random events set
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作者 LI Xuan GONG Mao-xun +1 位作者 KANG Xing CHEN Bing-rui 《Marine Science Bulletin》 CAS 2017年第1期24-36,共13页
In order to study whether the random events set can be used in Rudongbank of Nantong or not, we use ADCIRC model to stimulate the storm surge affectingRudong bank based on random events set. Then we use p-III curve to... In order to study whether the random events set can be used in Rudongbank of Nantong or not, we use ADCIRC model to stimulate the storm surge affectingRudong bank based on random events set. Then we use p-III curve to fit peak-value ofsurge of all the years to get the surge of typical return periods. The result shows that theresults of fitting by ADCIRC and by historical data coincide well in lower return periods,but to higher return periods, the results of fitting by ADCIRC are significantly higher thanthat of fitting by historical data. Due to the short time, it’s not enough for the extremestorm surge events to occur, the results of higher return periods are not reliable, so wecan’t rule out the reasonability of results based on random events set. The results offitting based on random events set are accurate in lower return periods and we can alsofully estimate the surge of higher return periods based on random events set. In thesituation of lacking historical data of hundreds of years, random events set can beaccepted as a tool to compute the return period of storm surge. Consideration of globalwarming, the possibility of super typhoons’ appearance will rise, which will result inhigher surge of return periods. In order to prevent the disaster of storm surge, thegovernment needs to deepen and reinforce the coastal engineering like seawalls and embankments. 展开更多
关键词 random events set storm surge reasonability
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Methodology for the Ensemble Synthesis of Stochastic Seismic Event Sets Satisfying the Renewal Process for Local Strong Earthquakes
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作者 Cheng Jiang Pan Hua 《Applied Geophysics》 2025年第4期988-1002,1492,1493,共17页
Local strong seismic activity shows the potential to closely follow a renewal process,which is inconsistent with the overall seismic activity that aligns with the Poisson process.Given that existing methods for synthe... Local strong seismic activity shows the potential to closely follow a renewal process,which is inconsistent with the overall seismic activity that aligns with the Poisson process.Given that existing methods for synthesizing stochastic seismic event sets cannot control local seismic activity,a method based on Monte Carlo simulations has been developed for synthesizing random seismic event sets where local strong earthquakes satisfy the renewal process.This method can synthesize seismic activities in a statistical area where the overall activity conforms to the Poisson process and the major seismic activities in local potential sources or faults follow the renewal process.This paper presents long-and short-scale approaches.The long-scale earthquake catalogs are suitable for reflecting the sequential characteristics of seismic activities.Meanwhile,the short-scale catalogs focus on the impacts of specific earthquake events within a group for a detailed understanding of hazards under certain conditions,making them suitable for studies on specific earthquake sequences and geological areas or situations requiring high temporal resolution.In the applications of shortscale sequences,we find that the equivalent occurrence rate method may overestimate the seismic hazard.This synthesis method for earthquake catalogs can simulate realistic seismic activities,thereby enhancing the accuracy of hazard analysis results and is suitable for seismic hazard analysis and earthquake insurance rate setting. 展开更多
关键词 Seismic random event Set Monte Carlo Poisson Process Renewal Process
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Recovery of single event upset in advanced complementary metal-oxide semiconductor static random access memory cells 被引量:4
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作者 Qin Jun-Rui Chen Shu-Ming +1 位作者 Liang Bin Liu Bi-Wei 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第2期624-628,共5页
Using computer-aided design three-dimensional (3D) simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi... Using computer-aided design three-dimensional (3D) simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi-node charge collection plays a key role in recovery and shielding the charge sharing by adding guard rings. It cannot exhibit the recovery effect. It is also indicated that the upset linear energy transfer (LET) threshold is kept constant while the recovery LET threshold increases as the spacing increases. Additionally, the effect of incident angle on recovery is analysed and it is shown that a larger angle can bring about a stronger charge sharing effect, thus strengthening the recovery ability. 展开更多
关键词 single event upset multi-node charge collection static random access memory angulardependence
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Synergistic effects of total ionizing dose on single event upset sensitivity in static random access memory under proton irradiation
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作者 肖尧 郭红霞 +7 位作者 张凤祁 赵雯 王燕萍 张科营 丁李利 范雪 罗尹虹 王园明 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第11期612-615,共4页
Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flu... Synergistic effects of the total ionizing dose (TID) on the single event upset (SEU) sensitivity in static random access memories (SRAMs) were studied by using protons. The total dose was cumulated with high flux protons during the TID exposure, and the SEU cross section was tested with low flux protons at several cumulated dose steps. Because of the radiation-induced off-state leakage current increase of the CMOS transistors, the noise margin became asymmetric and the memory imprint effect was observed. 展开更多
关键词 single event upset total dose static random access memory imprint effect
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温度对14nm FinFET SRAM单粒子效应的影响
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作者 谭钧元 郭刚 +4 位作者 张付强 江宜蓓 陈启明 韩金华 秦丰迪 《半导体技术》 北大核心 2026年第1期87-93,共7页
由于鳍式场效应晶体管静态随机存储器(FinFET SRAM)特有的鳍片电荷共享机制,其对单粒子效应(SEE)呈现出与传统平面器件截然不同的敏感特性。利用TCAD仿真构建14 nm FinFET SRAM模型并结合重离子实验加以验证,研究了温度对14 nm FinFET S... 由于鳍式场效应晶体管静态随机存储器(FinFET SRAM)特有的鳍片电荷共享机制,其对单粒子效应(SEE)呈现出与传统平面器件截然不同的敏感特性。利用TCAD仿真构建14 nm FinFET SRAM模型并结合重离子实验加以验证,研究了温度对14 nm FinFET SRAM电荷收集机制的影响。结果表明,随着温度的升高,高线性能量转移(LET)离子诱导的电荷收集过程逐渐减弱,多节点电荷收集现象也会逐渐减弱,且当环境温度达到125℃临界值时,敏感节点会出现收集电荷的雪崩式累积现象。此外,随着温度的升高,器件的翻转截面从1.27×10^(-3)cm^(2)增大到1.81×10^(-3)cm^(2),增大了约43%,且在高温下翻转截面的增大趋势愈发显著,该结果与仿真结果良好吻合。 展开更多
关键词 鳍式场效应晶体管静态随机存储器(FinFET SRAM) 单粒子效应(SEE) 电荷收集 TCAD 温度
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一类随机基准系统的有限时间事件触发跟踪控制
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作者 徐绍君 张天润 +1 位作者 冯立康 姚立强 《鲁东大学学报(自然科学版)》 2026年第1期69-79,共11页
研究了随机环境中一类基准系统的有限时间事件触发自适应跟踪控制问题。为了方便控制器的设计和系统性能分析,引入了带有可调节参数的Lyapunov函数,并通过运用向量反推技术设计了有限时间自适应连续跟踪控制器,在此基础上设计了事件触... 研究了随机环境中一类基准系统的有限时间事件触发自适应跟踪控制问题。为了方便控制器的设计和系统性能分析,引入了带有可调节参数的Lyapunov函数,并通过运用向量反推技术设计了有限时间自适应连续跟踪控制器,在此基础上设计了事件触发机制,生成了有限时间事件触发跟踪控制器,以降低反馈信号信道传输负载,提高控制性能。仿真结果表明所提控制方案是可行有效的。 展开更多
关键词 随机干扰 有限时间 自适应律 事件触发控制
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Pattern dependence in synergistic effects of total dose on single-event upset hardness 被引量:1
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作者 郭红霞 丁李利 +4 位作者 肖尧 张凤祁 罗尹虹 赵雯 王园明 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期463-467,共5页
The pattern dependence in synergistic effects was studied in a 0.18 μm static random access memory(SRAM) circuit.Experiments were performed under two SEU test environments:3 Me V protons and heavy ions.Measured re... The pattern dependence in synergistic effects was studied in a 0.18 μm static random access memory(SRAM) circuit.Experiments were performed under two SEU test environments:3 Me V protons and heavy ions.Measured results show different trends.In heavy ion SEU test,the degradation in the peripheral circuitry also existed because the measured SEU cross section decreased regardless of the patterns written to the SRAM array.TCAD simulation was performed.TIDinduced degradation in n MOSFETs mainly induced the imprint effect in the SRAM cell,which is consistent with the measured results under the proton environment,but cannot explain the phenomena observed under heavy ion environment.A possible explanation could be the contribution from the radiation-induced GIDL in pMOSFETs. 展开更多
关键词 pattern dependence total dose single event upset(SEU) static random access memory(SRAM)
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Study of the Enhancement Events of Relativistic Electron at the Geosynchronous Orbit
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作者 B. S. Xue 《空间科学学报》 CAS CSCD 北大核心 2005年第5期383-386,共4页
The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures ... The high flux of energetic electron on geostationary orbit can induce many kinds of malfunction of the satellite there, within which the bulk-charging is the most significant that several broadcast satellite failures were confirmed to be due to this effect. The electron flux on geostationary orbit varies in a large range even up to three orders accompanied the passage of interplanetary magnetic cloud and the following geomagnetic disturbances. Upon the investigation of electron flux enhancement events, two types of events were partitioned as recurrent events and random ones. Both of the two kinds of events relate to the interplanetary conditions such as solar wind parameters, IMF etc and their evolution characters as well. As for the recurrent events, we found that, (1) all of the events exhibits periodic recurrence about 27 days, (2) significant increase of electron flux relates to interplanetary index and characters of their distribution, (3) the electron flux also has relation to solar activity index. An artificial neural network was constructed to estimate the flux I day ahead. The random electron flux enhancement events are rare and present different distribution figures to the recurrent ones. The figure of the random events and the conditions of their occurrence is also discussed in this paper. 展开更多
关键词 地球 轨道 电子 太阳风 随机事件
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First principles simulation technique for characterizing single event effects 被引量:1
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作者 张科营 郭红霞 +5 位作者 罗尹虹 范如玉 陈伟 林东生 郭刚 闫逸华 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第6期524-529,共6页
This paper develops a new simulation technique to characterize single event effects on semiconductor devices. The technique used to calculate the single event effects is developed according to the physical interaction... This paper develops a new simulation technique to characterize single event effects on semiconductor devices. The technique used to calculate the single event effects is developed according to the physical interaction mechanism of a single event effect. An application of the first principles simulation technique is performed to predict the ground-test single event upset effect on field-programmable gate arrays based on 0.25μm advanced complementary metal-oxidesemiconductor technology. The agreement between the single event upset cross section accessed from a broad-beam heavy ion experiment and simulation shows that the simulation technique could be used to characterize the single event effects induced by heavy ions on a semiconductor device. 展开更多
关键词 single event effect static random access memory cross section SIMULATION
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A NEW EVIDENCE UPDATING RULE BASED ON CONDITIONAL EVENT
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作者 Wen Chenglin Wang Yingchang Xu Xiaobin 《Journal of Electronics(China)》 2009年第6期731-737,共7页
Updating or conditioning a body of evidence modeled within the DS framework plays an important role in most of Artificial Intelligence (AI) applications. Rule is one of the most important methods to represent knowledg... Updating or conditioning a body of evidence modeled within the DS framework plays an important role in most of Artificial Intelligence (AI) applications. Rule is one of the most important methods to represent knowledge in AI. The appearance of uncertain reasoning urges us to measure the belief of rule. Now,most of uncertain reasoning models represent the belief of rule by conditional probability. However,it has many limitations when standard conditional probability is used to measure the belief of expert system rule. In this paper,AI rule is modelled by conditional event and the belief of rule is measured by conditional event probability,then we use random conditional event to construct a new evidence updating method. It can overcome the drawback of the existed methods that the forms of focal sets influence updating result. Some examples are given to illustrate the effectiveness of the proposed method. 展开更多
关键词 Conditional event random conditional event Belief of inference rule Updating rule
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Environment-dependent continuous time random walk
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作者 林方 包景东 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第4期103-108,共6页
A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory: the jumping distance and the waiting time, are ... A generalized continuous time random walk model which is dependent on environmental damping is proposed in which the two key parameters of the usual random walk theory: the jumping distance and the waiting time, are replaced by two new ones: the pulse velocity and the flight time. The anomalous diffusion of a free particle which is characterized by the asymptotical mean square displacement (x^2(t)) - t^a is realized numerically and analysed theoretically, where the value of the power index a is in a region of 0 〈 a 〈 2. Particularly, the damping leads to a sub-diffusion when the impact velocities are drawn from a Gaussian density function and the super-diffusive effect is related to statistical extremes, which are called rare-though-dominant events. 展开更多
关键词 continuous time random walk environment-dependent rare-though-dominate events anomalous diffusion
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Analysis of Nonlinear Stochastic Systems with Jumps Generated by Erlang Flow of Events
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作者 Alexander S. Kozhevnikov Konstantin A. Rybakov 《Open Journal of Applied Sciences》 2013年第1期1-7,共7页
In this paper we consider the stochastic systems with jumps (random impulses) generated by Erlang flow of events that lead to discontinuities in paths. These systems may be used in various applications such as a contr... In this paper we consider the stochastic systems with jumps (random impulses) generated by Erlang flow of events that lead to discontinuities in paths. These systems may be used in various applications such as a control of complex technical systems, financial mathematics, mathematical biology and medicine. We propose to use a spectral method formalism to the probabilistic analysis problem for the stochastic systems with jumps. This method allows to get a solution of the analysis problem in an explicit form. 展开更多
关键词 ANALYSIS ERLANG FLOW of eventS Generalized Fokker-Planck Equations random Impulses JUMP-DIFFUSION Process SPECTRAL Characteristic SPECTRAL Method Formalism Stochastic System
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沙库巴曲缬沙坦治疗射血分数保留的心力衰竭安全性的Meta分析 被引量:1
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作者 刘清清 王苏苹 +2 位作者 王林江 袁媛 周振宇 《心肺血管病杂志》 2025年第2期191-199,共9页
目的:探索沙库巴曲缬沙坦治疗射血分数保留的心力衰竭的安全性。方法:检索PubMed、Web of Science、Embase等数据库自建库至2024年4月,沙库巴曲缬沙坦治疗射血分数保留的心力衰竭的随机对照试验。由2名研究者独立筛选文献、提取资料并... 目的:探索沙库巴曲缬沙坦治疗射血分数保留的心力衰竭的安全性。方法:检索PubMed、Web of Science、Embase等数据库自建库至2024年4月,沙库巴曲缬沙坦治疗射血分数保留的心力衰竭的随机对照试验。由2名研究者独立筛选文献、提取资料并评价纳入研究的偏倚风险,采用RevMan5.3软件进行Meta分析。结果:与缬沙坦/依那普利/安慰剂相比,沙库巴曲缬沙坦可显著改善HFpEF患者的心力衰竭住院(RR=0.90,95%CI:0.84~0.96,P=0.001)和心力衰竭急性发作(RR=0.70,95%CI:0.53~0.94,P=0.02)的结果,发生肾损伤(RR=0.61,95%CI:0.41~0.92,P=0.02)、使肾小球滤过率下降>50%(RR=0.61,95%CI:0.41~0.92,P=0.02)和至少一次不良事件(RR=0.69,95%CI:0.48~0.97,P=0.03)的风险更低,但发生低血压(RR=1.58,95%CI:1.12~2.23,P=0.009)和血管性水肿(RR=2.22,95%CI:1.01~4.87,P=0.05)的风险更高。结论:沙库巴曲缬沙坦用于治疗射血分数保留的心力衰竭时,可更有效的减少心力衰竭住院及急性心力衰竭发作,且可减少肾损伤及不良事件的发生,但更易导致低血压及血管性水肿。 展开更多
关键词 射血分数保留的心力衰竭 沙库巴曲缬沙坦 不良事件 随机对照实验 荟萃分析
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Riemann Hypothesis, Catholic Information and Potential of Events with New Techniques for Financial and Other Applications
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作者 Prodromos Char. Papadopoulos 《Advances in Pure Mathematics》 2021年第5期524-572,共49页
In this research we are going to define two new concepts: a) “The Potential of Events” (EP) and b) “The Catholic Information” (CI). The term CI derives from the ancient Greek language and declares all the Catholic... In this research we are going to define two new concepts: a) “The Potential of Events” (EP) and b) “The Catholic Information” (CI). The term CI derives from the ancient Greek language and declares all the Catholic (general) Logical Propositions (<img src="Edit_5f13a4a5-abc6-4bc5-9e4c-4ff981627b2a.png" width="33" height="21" alt="" />) which will true for every element of a set A. We will study the Riemann Hypothesis in two stages: a) By using the EP we will prove that the distribution of events e (even) and o (odd) of Square Free Numbers (SFN) on the axis Ax(N) of naturals is Heads-Tails (H-T) type. b) By using the CI we will explain the way that the distribution of prime numbers can be correlated with the non-trivial zeros of the function ζ(s) of Riemann. The Introduction and the Chapter 2 are necessary for understanding the solution. In the Chapter 3 we will present a simple method of forecasting in many very useful applications (e.g. financial, technological, medical, social, etc) developing a generalization of this new, proven here, theory which we finally apply to the solution of RH. The following Introduction as well the Results with the Discussion at the end shed light about the possibility of the proof of all the above. The article consists of 9 chapters that are numbered by 1, 2, …, 9. 展开更多
关键词 Twin Problem Twin’s Problem Unsolved Mathematical Problems Prime Number Problems Millennium Problems Riemann Hypothesis Riemann’s Hypothesis Number Theory Information Theory Probabilities Statistics Management Financial Applications Arithmetical Analysis Optimization Theory Stock Exchange Mathematics Approximation Methods Manifolds Economical Mathematics random Variables Space of events Strategy Games Probability Density Stock Market Technical Analysis Forecasting
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中国九大流域干湿复合事件时空演变及其驱动力分析 被引量:1
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作者 曹倩倩 黄生志 +5 位作者 邓晓雅 段利民 黄强 高月娇 董海霞 王浩 《农业工程学报》 北大核心 2025年第7期111-120,共10页
与单一的干旱和洪涝相比,干旱和洪涝之间的突然转变可能会对生态和社会经济产生放大影响。然而,受气候变化和人类活动的影响,干湿复合事件的时空演变与驱动机制尚未明晰。基于此,该研究以中国为研究区域,旨在探明1982—2022年中国干湿... 与单一的干旱和洪涝相比,干旱和洪涝之间的突然转变可能会对生态和社会经济产生放大影响。然而,受气候变化和人类活动的影响,干湿复合事件的时空演变与驱动机制尚未明晰。基于此,该研究以中国为研究区域,旨在探明1982—2022年中国干湿复合事件的动态演变特征与驱动因子。以标准化降水指数识别相邻季节间干湿复合事件,并利用Copula函数计算了干湿复合事件的联合概率;采用Mann-Kendall检验以20 a时间序列为滑动窗口探究干湿复合事件的发生概率的变化趋势;运用随机森林探讨干湿复合事件的驱动因子。结果表明:1)1982—2022年间春-夏、夏-秋和秋-冬都更易发生连续干旱事件,发生概率分别为4.04%、4.20%和4.04%,冬-春更易发生连续湿润事件,发生概率为4.69%;2)内陆河流域和珠江流域易在冬-春发生连续干旱事件;松辽河流域、淮河流域、黄河流域、海河流域和东南诸河流域易在冬-春发生连续湿润事件;长江流域易在夏-秋发生连续湿润事件;西南诸河流域易在夏-秋发生连续干旱事件;3)全国范围内,秋-冬连续湿润、冬-春连续湿润上升趋势显著,检验统计值分别为2.91和2.44。从不同流域分析,内陆河流域、黄河流域和海河流域上升趋势最明显的是秋-冬连续湿润事件,松辽河流域上升趋势最明显的是冬-春连续湿润事件,长江流域上升趋势最明显的是春-夏连续湿润事件,西南诸河上升趋势最明显的秋-冬连续干旱事件,东南诸河上升趋势最明显的是冬-春连续湿润事件;4)全国大部分流域的复合事件动态变化的主导因子都是气象因子,而下垫面因子对全国大部分流域的干湿复合事件影响相对较小,但对松辽河流域的影响相对较大。研究成果可为全国干湿复合事件的精准防御提供依据。 展开更多
关键词 干旱 洪涝 干湿复合事件 动态变化 驱动力 随机森林 COPULA函数
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亚20 nm FinFET SRAM工艺涨落对单粒子翻转特性的影响
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作者 孙乾 郭阳 +9 位作者 梁斌 池雅庆 陶明 罗登 陈建军 孙晗晗 胡春媚 方亚豪 高宇林 肖靖 《国防科技大学学报》 北大核心 2025年第6期264-273,共10页
为了探究工艺涨落对亚20纳米鳍式场效应晶体管(fin field-effect transistor,FinFET)工艺静态随机存储器(static random-access memory,SRAM)单粒子翻转特性的影响,通过建立与商用工艺接近的高精度三维计算机辅助工艺设计模型,对不同工... 为了探究工艺涨落对亚20纳米鳍式场效应晶体管(fin field-effect transistor,FinFET)工艺静态随机存储器(static random-access memory,SRAM)单粒子翻转特性的影响,通过建立与商用工艺接近的高精度三维计算机辅助工艺设计模型,对不同工艺角下FinFET SRAM的单粒子翻转特性进行仿真。仿真结果显示,FinFET工艺SRAM的单粒子翻转阈值在不同的工艺角变化下产生微小波动,且敏感位置都在N型金属氧化物半导体上。为了明确具体的工艺参数涨落对单粒子翻转阈值的影响,对鳍的厚度、鳍的高度、栅氧厚度、功函数波动造成的单粒子翻转特性的影响进行研究。仿真结果表明,前两种因素对翻转阈值未产生影响,后两种因素对翻转阈值造成了微小的波动。首次发现工艺涨落对FinFET SRAM单粒子翻转阈值的影响大幅降低,该发现对研制高一致性的抗辐射宇航用集成电路具有重要意义。 展开更多
关键词 FINFET 单粒子翻转 静态随机存储器 工艺涨落 工艺角
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1980—2023年吉林省风雪复合极端事件时空变化特征
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作者 刘子琪 秦玉琳 +2 位作者 陈长胜 宋爽 纪玲玲 《冰川冻土》 2025年第6期1586-1596,共11页
与单一暴雪或大风灾害相比,风雪复合极端天气事件更易造成极端性灾害损失。本文选取吉林省1980—2023年逐日气温、降雪量、最小能见度、极大风速数据,以暴风雪天气指数(snowstorm weather index,SWI)表征风雪复合极端天气事件,利用随机... 与单一暴雪或大风灾害相比,风雪复合极端天气事件更易造成极端性灾害损失。本文选取吉林省1980—2023年逐日气温、降雪量、最小能见度、极大风速数据,以暴风雪天气指数(snowstorm weather index,SWI)表征风雪复合极端天气事件,利用随机森林(RF)模型构建延长极大风速序列,结合Mann-Kendall趋势检验和相关性分析方法,系统分析该区域风雪复合极端事件时空演变特征及其与各气象因子、地形的相关性。结果表明,利用随机森林模型延长极大风速时间序列的效果较好,R^(2)超过0.90。研究时段内各等级暴风雪天气日数均呈波动性增加趋势,且在2020年前后发生突变。暴风雪天气在每年的10月至次年3月均可发生,中度等级以上暴风雪天气站次比在11月最高,12月和1月最低。空间分布上暴风雪天气多发生于吉林省中东部,尤其是东部和南部地区,更易发生强和特强等级暴风雪天气,东部地区SWI呈减小趋势但变异性大;南部地区SWI呈增加趋势且变异性小。降雪量与SWI相关性最强,其次是与最低气温和极大风速,三者与SWI相关性均通过显著性检验,对评估未来风雪复合极端事件有较好指示意义。 展开更多
关键词 风雪复合极端事件 随机森林 时空变化 吉林省
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气候变化驱动下卓乃-盐湖流域的湖泊演变
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作者 梁玉梅 郭伟 倪向南 《生态学报》 北大核心 2025年第18期9294-9307,共14页
青藏高原是全球气候变化的敏感区,其湖泊受人类活动影响较小,成为研究气候变化的重要指示器。21世纪以来,青藏高原气候呈现明显的暖湿化趋势,极端气候事件频发,导致大多数湖泊扩张。2011年卓乃湖溃堤事件导致流域内一系列湖泊效应,对当... 青藏高原是全球气候变化的敏感区,其湖泊受人类活动影响较小,成为研究气候变化的重要指示器。21世纪以来,青藏高原气候呈现明显的暖湿化趋势,极端气候事件频发,导致大多数湖泊扩张。2011年卓乃湖溃堤事件导致流域内一系列湖泊效应,对当地生态系统及环境稳定性产生了深远影响。本研究利用随机森林模型提取卓乃-盐湖流域水体变化数据,结果显示:卓乃湖面积从8月20日的271km^(2)减少到11月8日的166km^(2),萎缩了105km^(2);而盐湖面积从2010年的47.8km^(2)扩张到了2019年的207km^(2),湖面扩张近3倍。卓乃湖水量在一年内减少了8.1×10^(8)m^(3),而盐湖水量持续增长,总量增加了28.2×10^(8)m^(3)。随机森林回归分析表明,气温和降水是湖泊动态变化的主要驱动因素,分别贡献了46%和17%。增温导致冰川消融加剧,短时极端降水事件触发湖水水位激增,加之长期降水增长趋势的共同作用,最终导致了卓乃湖的溃决事件。溃决事件导致盐湖水位上升,严重威胁青藏铁路、青藏公路等基础设施;同时,卓乃湖岸线后退引发土地沙漠化,影响藏羚羊的水源获取和食物供应,威胁其生存环境。揭示了暖湿化背景下卓乃-盐湖流域湖泊的演变过程及环境响应,为高原湖泊动态变化及其生态风险评估提供了科学依据。 展开更多
关键词 卓乃湖溃决事件 随机森林 气候响应 生态效应
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随机森林算法在识别护理不良事件风险中的应用
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作者 王静 何锦洋 +2 位作者 方萍萍 武怡伶 刘晓 《护理研究》 北大核心 2025年第24期4172-4175,共4页
目的:探讨随机森林算法在护理不良事件关键风险因子识别中的应用价值,为早期识别与干预不良事件潜在风险提供临床依据。方法:回顾性分析某三级甲等医院659起住院病人护理不良事件,利用Jupyter编译器,通过Python编程语言结合Sklearn库构... 目的:探讨随机森林算法在护理不良事件关键风险因子识别中的应用价值,为早期识别与干预不良事件潜在风险提供临床依据。方法:回顾性分析某三级甲等医院659起住院病人护理不良事件,利用Jupyter编译器,通过Python编程语言结合Sklearn库构建随机森林预测模型,按3∶1划分训练集与验证集,开展模型预测效能的训练与测试。结果:护理不良事件发生率为0.352%。随机森林算法分析表明,病人跌倒风险评分、Barthel指数、新入职护士上岗月份为权重占比较高的变量,病人年龄、科室、时间段、护士层级、病人依从性、护士决策能力及院区均为影响因素。模型准确率为74.7%,召回率为75%,F1值为72%,受试者工作特征曲线下面积为0.89。结论:借助随机森林算法剖析不良事件关键风险因子并实施针对性预警措施,可为临床护理不良事件防控提供参考,也为探索护理新质生产力发展路径提供方向。 展开更多
关键词 护理质量 不良事件 随机森林算法 护理管理
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