Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel...Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel and spectral reflectance. Results show that after the dry, hot and windy summer in 2007, many landscape trees in Yamaguchi City tended to respond the extreme weather events by reducing their leaf surface area and receiving less radiation energy. Premature leaf discoloration or defoliation appeared on some landscape tree species and leaf necrosis occurred on tip and margin of many Kousa dogwood (Cornus kousa) trees at unfavorable sites. Described by image pixel analysis method, the leaf necrotic area percentage (LNAP) of sampled dogwood trees averaged 41.6% and the sampled Sasanqua camellia (Camelia sasanqua) tree also showed fewer flowers in flower season of 2007 than that in 2006. By differential analysis of partial discolored crown, it presented a logistic differential equation of crown color for sweet gum (Liquidambar styraciflua) trees. It suggested that the persistent higher temperature and lower precipitation could be injurious to the sensitive landscape trees at poor sites, even in relative humid area like Yamaguchi.展开更多
During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped wit...During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped with independent air ducts.In this paper,a two-step method is used for numerical computation:(1)obtaining the temporal and spatial transient node data of the flow field sections during the train-passing simulation and(2)using the data as the input data for the equipment compartment simulation.In addition,this paper also compares the difference in equipment ventilation between the single-train and trainpassing scenarios in real vehicle tests.The results indicate that the primary factors influencing ventilation effectiveness are the aerodynamic compression and deceleration of airflow induced by the other train's nose,as well as the instability of the external flow field in the wake of the other train.During train crossing,the air is forced into the air duct,with a maximum ratio of the airflow in-duct to the airflow out-duct reaching 3.2.The average mass flow falls below the rated mass flow for the converter.Compared to the rated air volume of converter,the maximum suppression rates obtained from testing and simulation are-24.5%and-16.8%,respectively.Compared to the single-train operation,the maximum suppression rates obtained from testing and simulation are-15%and-18%,respectively.These findings provide valuable insights into the design and operation of high-speed trains.展开更多
The single event effects(SEEs)evaluations caused by atmospheric neutrons were conducted on three different convolutional neural network(CNN)models(Yolov3,MNIST,and ResNet50)in the atmospheric neutron irradiation spect...The single event effects(SEEs)evaluations caused by atmospheric neutrons were conducted on three different convolutional neural network(CNN)models(Yolov3,MNIST,and ResNet50)in the atmospheric neutron irradiation spectrometer(ANIS)at the China Spallation Neutron Source(CSNS).The Yolov3 and MNIST models were implemented on the XILINX28-nm system-on-chip(So C).Meanwhile,the Yolov3 and ResNet50 models were deployed on the XILINX 16-nm Fin FET Ultra Scale+MPSoC.The atmospheric neutron SEEs on the tested CNN systems were comprehensively evaluated from six aspects,including chip type,network architecture,deployment methods,inference time,datasets,and the position of the anchor boxes.The various types of SEE soft errors,SEE cross-sections,and their distribution were analyzed to explore the radiation sensitivities and rules of 28-nm and 16-nm SoC.The current research can provide the technology support of radiation-resistant design of CNN system for developing and applying high-reliability,long-lifespan domestic artificial intelligence chips.展开更多
The pick-up algorithm by the k-th order cluster for the closest distance is used in the fields of weather and climactic events, and the technical terms clustered index and high clustered region are defined to investig...The pick-up algorithm by the k-th order cluster for the closest distance is used in the fields of weather and climactic events, and the technical terms clustered index and high clustered region are defined to investigate their temporal and spatial distribution characteristics in China during the past 50 years. The results show that the contribution of extreme high-temperature event clusters changed in the period from the 1960s to the 1970s, and its strength was enhanced. On the other hand, the decreasing trend in the clusters of low-temperature extremes can be taken as a signal for warmer winters to follow in the decadal time scale. Torrential rain and heavy rainfall clusters have both been lessened in the past 50 years, and have different cluster characteristics because of their definitions. Regions with high clustered indexes are concentrated in southern China. The spatial evolution of the heavy rainfall clusters reveals that clustered heavy rainfall has played an important role in the rain-belt pattern over China during the last 50 years.展开更多
Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel...Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel and spectral reflectance, Results show that after the dry, hot and windy summer in 2007, many landscape trees in Yamaguchi City tended to respond the extreme weather events by re- ducing their leaf surface area and receiving less radiation energy. Premature leaf discoloration or defoliation appeared on some landscape tree species and leaf necrosis occurred on tip and margin of many Kousa dogwood （Comus kousa） trees at unfavorable sites. Described by image pixel analysis method, the leaf necrotic area percentage （LNAP） of sampled dogwood trees averaged 41.6% and the sampled Sasanqua camellia （Camelia sasanqua） tree also showed fewer flowers in flower season of 2007 than that in 2006. By differential analysis of partial discolored crown, it presented a logistic differential equation of crown color for sweet gum （Liquidambar styraciflua） trees. It suggested that the persistent higher temperature and lower precipitation could be injurious to the sensitive landscape trees at poor sites, even in relative humid area like Yamaguchi.展开更多
The tectonic event during Cretaceous and its relationship with hydrocarbon accumulation in the Qiangtang Basin is discussed based on zircon U-Pb dating and the study of deformation, thermochronology and hydrocarbon fo...The tectonic event during Cretaceous and its relationship with hydrocarbon accumulation in the Qiangtang Basin is discussed based on zircon U-Pb dating and the study of deformation, thermochronology and hydrocarbon formation. LA-ICPMS zircon U-Pb dating indicates that the tectonic event took place during the Early-Late Cretaceous （125-75Ma）. The event not only established the framework and the styles of structural traps in the basin, but also led to the cessation of the first hydrocarbon formation and the destruction of previous oil pools. The light crude oil in the basin was formed during the second hydrocarbon formation stage in the Cenozoic, and ancient structural traps formed during the Cretaceous event are promising targets for oil and gas exploration.展开更多
This paper is devoted to studying the conformal invariance and Noether symmetry and Lie symmetry of a holonomic mechanical system in event space. The definition of the conformal invariance and the corresponding confor...This paper is devoted to studying the conformal invariance and Noether symmetry and Lie symmetry of a holonomic mechanical system in event space. The definition of the conformal invariance and the corresponding conformal factors of the holonomic system in event space are given. By investigating the relation between the conformal invariance and the Noether symmetry and the Lie symmetry, expressions of conformal factors of the system under these circumstances are obtained, and the Noether conserved quantity and the Hojman conserved quantity directly derived from the conformal invariance are given. Two examples are given to illustrate the application of the results.展开更多
This paper focuses on studying the Poisson theory and the integration method of a Birkhoffian system in the event space. The Birkhoff＇s equations in the event space are given. The Poisson theory of the Birkhoffian sy...This paper focuses on studying the Poisson theory and the integration method of a Birkhoffian system in the event space. The Birkhoff＇s equations in the event space are given. The Poisson theory of the Birkhoffian system in the event space is established. The definition of the Jacobi last multiplier of the system is given, and the relation between the Jacobi last multiplier and the first integrals of the system is discussed. The researches show that for a Birkhoffian system in the event space, whose configuration is determined by （2n ＋ 1） Birkhoff＇s variables, the solution of the system can be found by the Jacobi last multiplier if 2n first integrals are known. An example is given to illustrate the application of the results.展开更多
Variation of substrate background doping will affect the charge collection of active and passive MOSFETs in complementary metal-oxide semiconductor （CMOS） technologies, which are significant for charge sharing, thus...Variation of substrate background doping will affect the charge collection of active and passive MOSFETs in complementary metal-oxide semiconductor （CMOS） technologies, which are significant for charge sharing, thus affecting the propagated single event transient pulsewidths in circuits. The trends of charge collected by the drain of a positive channel metal-oxide semiconductor （PMOS） and an N metal-oxide semiconductor （NMOS） are opposite as the substrate doping increases. The PMOS source will inject carriers after strike and the amount of charge injected will irlcrease as the substrate doping increases, whereas the source of the NMOS will mainly collect carriers and the source of the NMOS can also inject electrons when the substrate doping is light enough. Additionally, it indicates that substrate doping mainly affects the bipolar amplification component of a single-event transient current, and has little effect on the drift and diffusion. The change in substrate doping has a much greater effect on PMOS than on NMOS.展开更多
Using computer-aided design three-dimensional simulation technology,the supply voltage scaled dependency of the recovery of single event upset and charge collection in static random-access memory cells are investigate...Using computer-aided design three-dimensional simulation technology,the supply voltage scaled dependency of the recovery of single event upset and charge collection in static random-access memory cells are investigated.It reveals that the recovery linear energy transfer threshold decreases with the supply voltage reducing,which is quite attractive for dynamic voltage scaling and subthreshold circuit radiation-hardened design.Additionally,the effect of supply voltage on charge collection is also investigated.It is concluded that the supply voltage mainly affects the bipolar gain of the parasitical bipolar junction transistor（BJT） and the existence of the source plays an important role in supply voltage variation.展开更多
In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation m...In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.展开更多
In the re-entry phase of a ballistic missile,decoys can be deployed as a mean to overburden enemy defenses.This results in a single track being split into multiple track-lets.Tracking of these track-lets is a critical...In the re-entry phase of a ballistic missile,decoys can be deployed as a mean to overburden enemy defenses.This results in a single track being split into multiple track-lets.Tracking of these track-lets is a critical task as any miss in the tracking procedure can become a cause of a major threat.The tracking process becomes more complicated in the presence of clutter.The low detection rate is one of the factors that may contribute to increasing the difficulty level in terms of tracking in the cluttered environment.This work introduces a new algorithm for the split event detection and target tracking under the framework of the joint integrated probabilistic data association(JIPDA)algorithm.The proposed algorithm is termed as split event-JIPDA(SE-JIPDA).This work establishes the mathematical foundation for the split target detection and tracking mechanism.The performance analysis is made under different simulation conditions to provide a clear insight into the merits of the proposed algorithm.The performance parameters in these simulations are the root mean square error(RMSE),confirmed true track rate(CTTR)and confirmed split true track rate(CSTTR).展开更多
Static effort of rock mass very rarely causes of rock burst in polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or s...Static effort of rock mass very rarely causes of rock burst in polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or sliding in roof layers above the exploited panel in coal seam, sometime in a distance from actual exploitation. Sliding, as a rule occurs in fault zone and tremors in it are expected, but monolithic layer rupture is very hard to predict. In a past few years a practice of analyzing state of deformation in high energy seismic tremors zones has been employed. It let gathering experience thanks to witch determination of dangerous shape of reformatted roof is possible. In the paper some typical forms of roof rocks deformations leading to seismic tremor occurrence will be presented. In general these are various types of multidirectional rock layers bending. Real examples of seismic events and rock bursts will be shown.展开更多
BACKGROUND:The accelerated diagnostic protocol(ADP)using the Emergency Department Assessment of Chest pain Score(EDACS-ADP),a tool to identify patients at low risk of a major adverse cardiac event(MACE)among patients ...BACKGROUND:The accelerated diagnostic protocol(ADP)using the Emergency Department Assessment of Chest pain Score(EDACS-ADP),a tool to identify patients at low risk of a major adverse cardiac event(MACE)among patients presenting with chest pain to the emergency department,was developed using a contemporary troponin assay.This study was performed to validate and compare the performance of the EDACS-ADP incorporating high-sensitivity cardiac troponin I between patients who had a 30-day MACE with and without unstable angina(MACE I and II,respectively).METHODS:A single-center prospective observational study of adult patients presenting with chest pain suggestive of acute coronary syndrome was performed.The performance of EDACS-ADP in predicting MACE was assessed by calculating the sensitivity and negative predictive value.RESULTS:Of the 1,304 patients prospectively enrolled,399(30.6%;95%confidence interval[95%CI]:27.7%–33.8%)were considered low-risk using the EDACS-ADP.Among them,the rates of MACE I and II were 1.3%(5/399)and 1.0%(4/399),respectively.The EDACS-ADP showed sensitivities and negative predictive values of 98.8%(95%CI:97.2%–99.6%)and 98.7%(95%CI:97.0%–99.5%)for MACE I and 98.7%(95%CI:96.8%–99.7%)and 99.0%(95%CI:97.4%–99.6%)for MACE II,respectively.CONCLUSION:EDACS-ADP could help identify patients as safe for early discharge.However,when unstable angina was added to the outcome,the 30-day MACE rate among the designated lowrisk patients remained above the level acceptable for early discharge without further evaluation.展开更多
Purpose:The purpose of this study is to serve as a comprehensive review of the existing annotated corpora.This review study aims to provide information on the existing annotated corpora for event extraction,which are ...Purpose:The purpose of this study is to serve as a comprehensive review of the existing annotated corpora.This review study aims to provide information on the existing annotated corpora for event extraction,which are limited but essential for training and improving the existing event extraction algorithms.In addition to the primary goal of this study,it provides guidelines for preparing an annotated corpus and suggests suitable tools for the annotation task.Design/methodology/approach:This study employs an analytical approach to examine available corpus that is suitable for event extraction tasks.It offers an in-depth analysis of existing event extraction corpora and provides systematic guidelines for researchers to develop accurate,high-quality corpora.This ensures the reliability of the created corpus and its suitability for training machine learning algorithms.Findings:Our exploration reveals a scarcity of annotated corpora for event extraction tasks.In particular,the English corpora are mainly focused on the biomedical and general domains.Despite the issue of annotated corpora scarcity,there are several high-quality corpora available and widely used as benchmark datasets.However,access to some of these corpora might be limited owing to closed-access policies or discontinued maintenance after being initially released,rendering them inaccessible owing to broken links.Therefore,this study documents the available corpora for event extraction tasks.Research limitations:Our study focuses only on well-known corpora available in English and Chinese.Nevertheless,this study places a strong emphasis on the English corpora due to its status as a global lingua franca,making it widely understood compared to other languages.Practical implications:We genuinely believe that this study provides valuable knowledge that can serve as a guiding framework for preparing and accurately annotating events from text corpora.It provides comprehensive guidelines for researchers to improve the quality of corpus annotations,especially for event extraction tasks across various domains.Originality/value:This study comprehensively compiled information on the existing annotated corpora for event extraction tasks and provided preparation guidelines.展开更多
The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are dist...The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are distributed on HFRS for particle identification and beam monitoring.The twin TPCs'readout electronics system operates in a trigger-less mode due to its high counting rate,leading to a challenge of handling large amounts of data.To address this problem,we introduced an event-building algorithm.This algorithm employs a hierarchical processing strategy to compress data during transmission and aggregation.In addition,it reconstructs twin TPCs'events online and stores only the reconstructed particle information,which significantly reduces the burden on data transmission and storage resources.Simulation studies demonstrated that the algorithm accurately matches twin TPCs'events and reduces more than 98%of the data volume at a counting rate of 500 kHz/channel.展开更多
Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on ...Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on the investigation of the requirements of railway real estate management and operation,combined with Beidou positioning,GIS(Geographic Information System),multi-source data fusion and other cutting-edge technologies,this paper puts forward the multi-dimensional dynamic statistical method of real estate information,the identification method of railway land occupation and the comprehensive evaluation method of real estate development and utilization potential,and build the railway real estate supervision and operation platform,design the function of the platform,so as to provide intelligent solutions for the railway real estate operation.展开更多
Offshore carbon dioxide(CO_(2)) geological storage(OCGS) represents a significant strategy for addressing climate change by curtailing greenhouse gas emissions. Nonetheless, the risk of CO_(2) leakage poses a substant...Offshore carbon dioxide(CO_(2)) geological storage(OCGS) represents a significant strategy for addressing climate change by curtailing greenhouse gas emissions. Nonetheless, the risk of CO_(2) leakage poses a substantial concern associated with this technology. This study introduces an innovative approach for establishing OCGS leakage scenarios, involving four pivotal stages, namely, interactive matrix establishment, risk matrix evaluation, cause–effect analysis, and scenario development, which has been implemented in the Pearl River Estuary Basin in China. The initial phase encompassed the establishment of an interaction matrix for OCGS systems based on features, events, and processes. Subsequent risk matrix evaluation and cause–effect analysis identified key system components, specifically CO_(2) injection and faults/features. Building upon this analysis, two leakage risk scenarios were successfully developed, accompanied by the corresponding mitigation measures. In addition, this study introduces the application of scenario development to risk assessment, including scenario numerical simulation and quantitative assessment. Overall, this research positively contributes to the sustainable development and safe operation of OCGS projects and holds potential for further refinement and broader application to diverse geographical environments and project requirements. This comprehensive study provides valuable insights into the establishment of OCGS leakage scenarios and demonstrates their practical application to risk assessment, laying the foundation for promoting the sustainable development and safe operation of ocean CO_(2) geological storage projects while proposing possibilities for future improvements and broader applications to different contexts.展开更多
Objective To investigate whether plasma big endothelin-1(ET-1) predicts ventricular arrythmias(VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator(ICD) indication patigents. Methods ...Objective To investigate whether plasma big endothelin-1(ET-1) predicts ventricular arrythmias(VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator(ICD) indication patigents. Methods In total, 207 patients fulfilling the inclusion criteria from Fuwai Hospital between January 2013 and December 2015 were retrospectively analyzed. The cohort was divided into three groups according to baseline plasma big ET-1 tertiles: tertile 1(< 0.38 pmol/L, n = 68), tertile 2(0.38–0.7 pmol/L, n = 69), and tertile 3(> 0.7 pmol/L, n = 70). The primary endpoints were VAs. The secondary endpoints were end-stage events comprising all-cause mortality and heart transplantation. Results During a mean follow-up period of 25.6 ± 13.9 months, 38(18.4%) VAs and 78(37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class(r = 0.165, P = 0.018), serum creatinine concentration(Scr;r = 0.147, P = 0.034), high-sensitivity C-reactive protein(hs-CRP;r = 0.217, P = 0.002), Lg NT-pro BNP(r = 0.463, P < 0.001), left ventricular end diastolic diameter(LVEDD;r = 0.234, P = 0.039) and negatively correlated with left ventricular ejection fraction(LVEF;r =-0.181, P = 0.032). Kaplan-Meier analysis showed that elevated big ET-1 was associated with increased risk of VAs and end-stage events(P < 0.05). In multivariate Cox regression models, big ET-1 was an independent risk factor for VAs(hazard ratio(HR) = 3.477, 95% confidence interval(CI): 1.352–8.940, P = 0.010, tertile 2 vs. tertile 1;HR = 4.112, 95% CI: 1.604–10.540, P = 0.003, tertile 3 vs. tertile 1) and end-stage events(HR = 2.804, 95% CI: 1.354–5.806, P = 0.005, tertile 2 vs. tertile 1;HR = 4.652, 95% CI: 2.288–9.459, P < 0.001, tertile 3 vs. tertile 1). Conclusions In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.展开更多
This paper investigates the temperature dependence of single-event transients（SETs） in 90-nm complementary metat-oxide semiconductor（CMOS） dual-well and triple-well negative metal-oxide semiconductor field-effect ...This paper investigates the temperature dependence of single-event transients（SETs） in 90-nm complementary metat-oxide semiconductor（CMOS） dual-well and triple-well negative metal-oxide semiconductor field-effect transistors（NMOSFETs）.Technology computer-aided design（TCAD） three-dimensional（3D） simulations show that the drain current pulse duration increases from 85 ps to 245 ps for triple-well but only increases from 65 ps to 98 ps for dual-well when the temperature increases from-55℃ to 125℃,which is closely correlated with the NMOSFET sources.This reveals that the pulse width increases with temperature in dual-well due to the weakening of the anti-amplification bipolar effect while increases with temperature in triple-well due to the enhancement of the bipolar amplification.展开更多
文摘Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel and spectral reflectance. Results show that after the dry, hot and windy summer in 2007, many landscape trees in Yamaguchi City tended to respond the extreme weather events by reducing their leaf surface area and receiving less radiation energy. Premature leaf discoloration or defoliation appeared on some landscape tree species and leaf necrosis occurred on tip and margin of many Kousa dogwood (Cornus kousa) trees at unfavorable sites. Described by image pixel analysis method, the leaf necrotic area percentage (LNAP) of sampled dogwood trees averaged 41.6% and the sampled Sasanqua camellia (Camelia sasanqua) tree also showed fewer flowers in flower season of 2007 than that in 2006. By differential analysis of partial discolored crown, it presented a logistic differential equation of crown color for sweet gum (Liquidambar styraciflua) trees. It suggested that the persistent higher temperature and lower precipitation could be injurious to the sensitive landscape trees at poor sites, even in relative humid area like Yamaguchi.
基金support by Technology R&D Program of China State Railway Group Co.,Ltd(Grant number N2022J013)the Hunan Provincial Innovation Foundation for Postgraduate(Grant number CX20220279)+1 种基金the Fundamental Research Funds for the Central Universities of Central South University(Grant number 2022ZZTS0193)China Scholarship Council(202106370112)。
文摘During the train meeting events,train equipment compartments are exposed to the worst pressure changes,potentially affecting the ventilation performance of equipment,particularly for electrical facilities equipped with independent air ducts.In this paper,a two-step method is used for numerical computation:(1)obtaining the temporal and spatial transient node data of the flow field sections during the train-passing simulation and(2)using the data as the input data for the equipment compartment simulation.In addition,this paper also compares the difference in equipment ventilation between the single-train and trainpassing scenarios in real vehicle tests.The results indicate that the primary factors influencing ventilation effectiveness are the aerodynamic compression and deceleration of airflow induced by the other train's nose,as well as the instability of the external flow field in the wake of the other train.During train crossing,the air is forced into the air duct,with a maximum ratio of the airflow in-duct to the airflow out-duct reaching 3.2.The average mass flow falls below the rated mass flow for the converter.Compared to the rated air volume of converter,the maximum suppression rates obtained from testing and simulation are-24.5%and-16.8%,respectively.Compared to the single-train operation,the maximum suppression rates obtained from testing and simulation are-15%and-18%,respectively.These findings provide valuable insights into the design and operation of high-speed trains.
基金Project supported by the National Natural Science Foundation of China(Grant No.12305303)the Natural Science Foundation of Hunan Province of China(Grant Nos.2023JJ40520,2024JJ2044,and 2021JJ40444)+3 种基金the Science and Technology Innovation Program of Hunan Province,China(Grant No.2020RC3054)the Postgraduate Scientific Research Innovation Project of Hunan Province,China(Grant No.CX20240831)the Natural Science Basic Research Plan in the Shaanxi Province of China(Grant No.2023-JC-QN0015)the Doctoral Research Fund of University of South China(Grant No.200XQD033)。
文摘The single event effects(SEEs)evaluations caused by atmospheric neutrons were conducted on three different convolutional neural network(CNN)models(Yolov3,MNIST,and ResNet50)in the atmospheric neutron irradiation spectrometer(ANIS)at the China Spallation Neutron Source(CSNS).The Yolov3 and MNIST models were implemented on the XILINX28-nm system-on-chip(So C).Meanwhile,the Yolov3 and ResNet50 models were deployed on the XILINX 16-nm Fin FET Ultra Scale+MPSoC.The atmospheric neutron SEEs on the tested CNN systems were comprehensively evaluated from six aspects,including chip type,network architecture,deployment methods,inference time,datasets,and the position of the anchor boxes.The various types of SEE soft errors,SEE cross-sections,and their distribution were analyzed to explore the radiation sensitivities and rules of 28-nm and 16-nm SoC.The current research can provide the technology support of radiation-resistant design of CNN system for developing and applying high-reliability,long-lifespan domestic artificial intelligence chips.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41005043 and 41105033)the National Basic Research Program of China(Grant No.2012CB955901)the National Science and Technology Ministry,China(Grant Nos.2007BAC29B01 and 2007BAC03A01)
文摘The pick-up algorithm by the k-th order cluster for the closest distance is used in the fields of weather and climactic events, and the technical terms clustered index and high clustered region are defined to investigate their temporal and spatial distribution characteristics in China during the past 50 years. The results show that the contribution of extreme high-temperature event clusters changed in the period from the 1960s to the 1970s, and its strength was enhanced. On the other hand, the decreasing trend in the clusters of low-temperature extremes can be taken as a signal for warmer winters to follow in the decadal time scale. Torrential rain and heavy rainfall clusters have both been lessened in the past 50 years, and have different cluster characteristics because of their definitions. Regions with high clustered indexes are concentrated in southern China. The spatial evolution of the heavy rainfall clusters reveals that clustered heavy rainfall has played an important role in the rain-belt pattern over China during the last 50 years.
文摘Extreme weather events were analyzed based on the meteorological data from the year of 1967 to 2007 for Yamaguchi, Japan. The responses from landscape trees were also investigated mainly by the analysis of image pixel and spectral reflectance, Results show that after the dry, hot and windy summer in 2007, many landscape trees in Yamaguchi City tended to respond the extreme weather events by re- ducing their leaf surface area and receiving less radiation energy. Premature leaf discoloration or defoliation appeared on some landscape tree species and leaf necrosis occurred on tip and margin of many Kousa dogwood （Comus kousa） trees at unfavorable sites. Described by image pixel analysis method, the leaf necrotic area percentage （LNAP） of sampled dogwood trees averaged 41.6% and the sampled Sasanqua camellia （Camelia sasanqua） tree also showed fewer flowers in flower season of 2007 than that in 2006. By differential analysis of partial discolored crown, it presented a logistic differential equation of crown color for sweet gum （Liquidambar styraciflua） trees. It suggested that the persistent higher temperature and lower precipitation could be injurious to the sensitive landscape trees at poor sites, even in relative humid area like Yamaguchi.
基金supported by the National Natural Science Foundation of China (40672086)the Ministry of Science and Technology "973" Project (2006CB701400)the Ministry of Land and Resources (XQ2004-06)
文摘The tectonic event during Cretaceous and its relationship with hydrocarbon accumulation in the Qiangtang Basin is discussed based on zircon U-Pb dating and the study of deformation, thermochronology and hydrocarbon formation. LA-ICPMS zircon U-Pb dating indicates that the tectonic event took place during the Early-Late Cretaceous （125-75Ma）. The event not only established the framework and the styles of structural traps in the basin, but also led to the cessation of the first hydrocarbon formation and the destruction of previous oil pools. The light crude oil in the basin was formed during the second hydrocarbon formation stage in the Cenozoic, and ancient structural traps formed during the Cretaceous event are promising targets for oil and gas exploration.
基金Project supported by the National Natural Science Foundation of China (Grant No10772025)the Natural Science Foundation of Higher Education Institution of Jiangsu Province of China (Grant No 08KJB130002)
文摘This paper is devoted to studying the conformal invariance and Noether symmetry and Lie symmetry of a holonomic mechanical system in event space. The definition of the conformal invariance and the corresponding conformal factors of the holonomic system in event space are given. By investigating the relation between the conformal invariance and the Noether symmetry and the Lie symmetry, expressions of conformal factors of the system under these circumstances are obtained, and the Noether conserved quantity and the Hojman conserved quantity directly derived from the conformal invariance are given. Two examples are given to illustrate the application of the results.
基金Project supported by the National Natural Science Foundation of China(Grant No.10972151)
文摘This paper focuses on studying the Poisson theory and the integration method of a Birkhoffian system in the event space. The Birkhoff＇s equations in the event space are given. The Poisson theory of the Birkhoffian system in the event space is established. The definition of the Jacobi last multiplier of the system is given, and the relation between the Jacobi last multiplier and the first integrals of the system is discussed. The researches show that for a Birkhoffian system in the event space, whose configuration is determined by （2n ＋ 1） Birkhoff＇s variables, the solution of the system can be found by the Jacobi last multiplier if 2n first integrals are known. An example is given to illustrate the application of the results.
基金Project supported by the State Key Program of the National Natural Science Foundation of China (Grant No. 60836004)the National Natural Science Foundation of China (Grant Nos. 61076025 and 61006070)
文摘Variation of substrate background doping will affect the charge collection of active and passive MOSFETs in complementary metal-oxide semiconductor （CMOS） technologies, which are significant for charge sharing, thus affecting the propagated single event transient pulsewidths in circuits. The trends of charge collected by the drain of a positive channel metal-oxide semiconductor （PMOS） and an N metal-oxide semiconductor （NMOS） are opposite as the substrate doping increases. The PMOS source will inject carriers after strike and the amount of charge injected will irlcrease as the substrate doping increases, whereas the source of the NMOS will mainly collect carriers and the source of the NMOS can also inject electrons when the substrate doping is light enough. Additionally, it indicates that substrate doping mainly affects the bipolar amplification component of a single-event transient current, and has little effect on the drift and diffusion. The change in substrate doping has a much greater effect on PMOS than on NMOS.
基金Project supported by the State Key Program of the National Natural Science Foundation of China (Grant No. 60836004)Hunan Provincial Innovation Foundation for Postgraduates,China (Grant No. CX2011B026)
文摘Using computer-aided design three-dimensional simulation technology,the supply voltage scaled dependency of the recovery of single event upset and charge collection in static random-access memory cells are investigated.It reveals that the recovery linear energy transfer threshold decreases with the supply voltage reducing,which is quite attractive for dynamic voltage scaling and subthreshold circuit radiation-hardened design.Additionally,the effect of supply voltage on charge collection is also investigated.It is concluded that the supply voltage mainly affects the bipolar gain of the parasitical bipolar junction transistor（BJT） and the existence of the source plays an important role in supply voltage variation.
基金supported by the National Natural Science Foundation of China(Grant No.61274106)
文摘In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.
文摘In the re-entry phase of a ballistic missile,decoys can be deployed as a mean to overburden enemy defenses.This results in a single track being split into multiple track-lets.Tracking of these track-lets is a critical task as any miss in the tracking procedure can become a cause of a major threat.The tracking process becomes more complicated in the presence of clutter.The low detection rate is one of the factors that may contribute to increasing the difficulty level in terms of tracking in the cluttered environment.This work introduces a new algorithm for the split event detection and target tracking under the framework of the joint integrated probabilistic data association(JIPDA)algorithm.The proposed algorithm is termed as split event-JIPDA(SE-JIPDA).This work establishes the mathematical foundation for the split target detection and tracking mechanism.The performance analysis is made under different simulation conditions to provide a clear insight into the merits of the proposed algorithm.The performance parameters in these simulations are the root mean square error(RMSE),confirmed true track rate(CTTR)and confirmed split true track rate(CSTTR).
文摘Static effort of rock mass very rarely causes of rock burst in polish coal mines. Rock bursts with source in the seismic tremor within the roof rock layers are prevailing. A seismic tremor is an effect of rupture or sliding in roof layers above the exploited panel in coal seam, sometime in a distance from actual exploitation. Sliding, as a rule occurs in fault zone and tremors in it are expected, but monolithic layer rupture is very hard to predict. In a past few years a practice of analyzing state of deformation in high energy seismic tremors zones has been employed. It let gathering experience thanks to witch determination of dangerous shape of reformatted roof is possible. In the paper some typical forms of roof rocks deformations leading to seismic tremor occurrence will be presented. In general these are various types of multidirectional rock layers bending. Real examples of seismic events and rock bursts will be shown.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government Ministry of Science and ICT(NRF-2021R1G1A101056711)。
文摘BACKGROUND:The accelerated diagnostic protocol(ADP)using the Emergency Department Assessment of Chest pain Score(EDACS-ADP),a tool to identify patients at low risk of a major adverse cardiac event(MACE)among patients presenting with chest pain to the emergency department,was developed using a contemporary troponin assay.This study was performed to validate and compare the performance of the EDACS-ADP incorporating high-sensitivity cardiac troponin I between patients who had a 30-day MACE with and without unstable angina(MACE I and II,respectively).METHODS:A single-center prospective observational study of adult patients presenting with chest pain suggestive of acute coronary syndrome was performed.The performance of EDACS-ADP in predicting MACE was assessed by calculating the sensitivity and negative predictive value.RESULTS:Of the 1,304 patients prospectively enrolled,399(30.6%;95%confidence interval[95%CI]:27.7%–33.8%)were considered low-risk using the EDACS-ADP.Among them,the rates of MACE I and II were 1.3%(5/399)and 1.0%(4/399),respectively.The EDACS-ADP showed sensitivities and negative predictive values of 98.8%(95%CI:97.2%–99.6%)and 98.7%(95%CI:97.0%–99.5%)for MACE I and 98.7%(95%CI:96.8%–99.7%)and 99.0%(95%CI:97.4%–99.6%)for MACE II,respectively.CONCLUSION:EDACS-ADP could help identify patients as safe for early discharge.However,when unstable angina was added to the outcome,the 30-day MACE rate among the designated lowrisk patients remained above the level acceptable for early discharge without further evaluation.
文摘Purpose:The purpose of this study is to serve as a comprehensive review of the existing annotated corpora.This review study aims to provide information on the existing annotated corpora for event extraction,which are limited but essential for training and improving the existing event extraction algorithms.In addition to the primary goal of this study,it provides guidelines for preparing an annotated corpus and suggests suitable tools for the annotation task.Design/methodology/approach:This study employs an analytical approach to examine available corpus that is suitable for event extraction tasks.It offers an in-depth analysis of existing event extraction corpora and provides systematic guidelines for researchers to develop accurate,high-quality corpora.This ensures the reliability of the created corpus and its suitability for training machine learning algorithms.Findings:Our exploration reveals a scarcity of annotated corpora for event extraction tasks.In particular,the English corpora are mainly focused on the biomedical and general domains.Despite the issue of annotated corpora scarcity,there are several high-quality corpora available and widely used as benchmark datasets.However,access to some of these corpora might be limited owing to closed-access policies or discontinued maintenance after being initially released,rendering them inaccessible owing to broken links.Therefore,this study documents the available corpora for event extraction tasks.Research limitations:Our study focuses only on well-known corpora available in English and Chinese.Nevertheless,this study places a strong emphasis on the English corpora due to its status as a global lingua franca,making it widely understood compared to other languages.Practical implications:We genuinely believe that this study provides valuable knowledge that can serve as a guiding framework for preparing and accurately annotating events from text corpora.It provides comprehensive guidelines for researchers to improve the quality of corpus annotations,especially for event extraction tasks across various domains.Originality/value:This study comprehensively compiled information on the existing annotated corpora for event extraction tasks and provided preparation guidelines.
基金partially supported by the Strategic Priority Research Program of Chinese Academy of Science(No.XDB 34030000)the National Natural Science Foundation of China(Nos.11975293 and 12205348)。
文摘The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are distributed on HFRS for particle identification and beam monitoring.The twin TPCs'readout electronics system operates in a trigger-less mode due to its high counting rate,leading to a challenge of handling large amounts of data.To address this problem,we introduced an event-building algorithm.This algorithm employs a hierarchical processing strategy to compress data during transmission and aggregation.In addition,it reconstructs twin TPCs'events online and stores only the reconstructed particle information,which significantly reduces the burden on data transmission and storage resources.Simulation studies demonstrated that the algorithm accurately matches twin TPCs'events and reduces more than 98%of the data volume at a counting rate of 500 kHz/channel.
基金supported by the Scientific and Technological Research and Development Plan of China Railway Beijing Group Co.,Ltd.(2022CT01).
文摘Railway real estate is the fundamental element of railway transportation production and operation.Effective management and rational utilization of railway real estate is essential for railway asset operation.Based on the investigation of the requirements of railway real estate management and operation,combined with Beidou positioning,GIS(Geographic Information System),multi-source data fusion and other cutting-edge technologies,this paper puts forward the multi-dimensional dynamic statistical method of real estate information,the identification method of railway land occupation and the comprehensive evaluation method of real estate development and utilization potential,and build the railway real estate supervision and operation platform,design the function of the platform,so as to provide intelligent solutions for the railway real estate operation.
文摘Offshore carbon dioxide(CO_(2)) geological storage(OCGS) represents a significant strategy for addressing climate change by curtailing greenhouse gas emissions. Nonetheless, the risk of CO_(2) leakage poses a substantial concern associated with this technology. This study introduces an innovative approach for establishing OCGS leakage scenarios, involving four pivotal stages, namely, interactive matrix establishment, risk matrix evaluation, cause–effect analysis, and scenario development, which has been implemented in the Pearl River Estuary Basin in China. The initial phase encompassed the establishment of an interaction matrix for OCGS systems based on features, events, and processes. Subsequent risk matrix evaluation and cause–effect analysis identified key system components, specifically CO_(2) injection and faults/features. Building upon this analysis, two leakage risk scenarios were successfully developed, accompanied by the corresponding mitigation measures. In addition, this study introduces the application of scenario development to risk assessment, including scenario numerical simulation and quantitative assessment. Overall, this research positively contributes to the sustainable development and safe operation of OCGS projects and holds potential for further refinement and broader application to diverse geographical environments and project requirements. This comprehensive study provides valuable insights into the establishment of OCGS leakage scenarios and demonstrates their practical application to risk assessment, laying the foundation for promoting the sustainable development and safe operation of ocean CO_(2) geological storage projects while proposing possibilities for future improvements and broader applications to different contexts.
基金supported by Natural Science Foundation of China(81470466)。
文摘Objective To investigate whether plasma big endothelin-1(ET-1) predicts ventricular arrythmias(VAs) and end-stage events in primary prevention implantable cardioverter-defibrillator(ICD) indication patigents. Methods In total, 207 patients fulfilling the inclusion criteria from Fuwai Hospital between January 2013 and December 2015 were retrospectively analyzed. The cohort was divided into three groups according to baseline plasma big ET-1 tertiles: tertile 1(< 0.38 pmol/L, n = 68), tertile 2(0.38–0.7 pmol/L, n = 69), and tertile 3(> 0.7 pmol/L, n = 70). The primary endpoints were VAs. The secondary endpoints were end-stage events comprising all-cause mortality and heart transplantation. Results During a mean follow-up period of 25.6 ± 13.9 months, 38(18.4%) VAs and 78(37.7%) end-stage events occurred. Big ET-1 was positively correlated with NYHA class(r = 0.165, P = 0.018), serum creatinine concentration(Scr;r = 0.147, P = 0.034), high-sensitivity C-reactive protein(hs-CRP;r = 0.217, P = 0.002), Lg NT-pro BNP(r = 0.463, P < 0.001), left ventricular end diastolic diameter(LVEDD;r = 0.234, P = 0.039) and negatively correlated with left ventricular ejection fraction(LVEF;r =-0.181, P = 0.032). Kaplan-Meier analysis showed that elevated big ET-1 was associated with increased risk of VAs and end-stage events(P < 0.05). In multivariate Cox regression models, big ET-1 was an independent risk factor for VAs(hazard ratio(HR) = 3.477, 95% confidence interval(CI): 1.352–8.940, P = 0.010, tertile 2 vs. tertile 1;HR = 4.112, 95% CI: 1.604–10.540, P = 0.003, tertile 3 vs. tertile 1) and end-stage events(HR = 2.804, 95% CI: 1.354–5.806, P = 0.005, tertile 2 vs. tertile 1;HR = 4.652, 95% CI: 2.288–9.459, P < 0.001, tertile 3 vs. tertile 1). Conclusions In primary prevention ICD indication patients, plasma big ET-1 levels can predict VAs and end-stage events and may facilitate ICD-implantation risk stratification.
基金Project supported by the State Key Program of the National Natural Science Foundation of China (Grant No. 60836004)Innovation Foundation for Postgraduate of Hunan Province,China (Grant No. CX2011B026)
文摘This paper investigates the temperature dependence of single-event transients（SETs） in 90-nm complementary metat-oxide semiconductor（CMOS） dual-well and triple-well negative metal-oxide semiconductor field-effect transistors（NMOSFETs）.Technology computer-aided design（TCAD） three-dimensional（3D） simulations show that the drain current pulse duration increases from 85 ps to 245 ps for triple-well but only increases from 65 ps to 98 ps for dual-well when the temperature increases from-55℃ to 125℃,which is closely correlated with the NMOSFET sources.This reveals that the pulse width increases with temperature in dual-well due to the weakening of the anti-amplification bipolar effect while increases with temperature in triple-well due to the enhancement of the bipolar amplification.
