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Evaluation of forecast performance for Super Typhoon Lekima in 2019

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Frontiers of Earth Science 2022年第1期16卷 17-33页

作者： Guomin CHEN Xiping ZHANG Qing CAO zhihua zeng Key Laboratory of Meteorological Disaster(Ministry of Education)/Joint International Research Laboratory of Climate and Environmental Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Shanghai Typhoon Institute of China Meteorological Administration Shanghai 200030China Shanghai Typhoon Institute and Key Laboratory of Numerical Modeling for Tropical Cyclone of China Meteorological AdministrationShanghai 200030China Shanghai Marine Center Meteorological Observatory Shanghai 200030China

The predictions for Super Typhoon Lekima(2019)have been evaluated from official forecasts,global models,regional models and ensemble prediction systems(EPSs)at lead times of 1–5 *** errors from most deterministic forecasts are smaller than their annual mean errors in *** to the propagation speed,the propagation direction of Lekima(2019)was much easier to determine for the official agency and numerical weather prediction(NWP)*** National Centers for Environmental Prediction Global Ensemble Forecast System(NCEP-GEFS),Japan Meteorological Agency Global Ensemble Prediction System(JMA-GEPS)and Meteorological Service of Canada Ensemble System(MSC-CENS)are underdispersed,and the Shanghai Typhoon Institute Typhoon Ensemble Data Assimilation and Prediction System(STI-TEDAPS)is overdispersed,while the ensemble prediction system from European Centre for Medium-Range Weather Forecasts(ECMWF)shows adequate dispersion at all lead *** deterministic forecasting methods underestimated the intensity of Lekima(2019),especially for the rapid intensification period after Lekima(2019)entered the East China *** of the deterministic forecasts performed well at predicting the first landfall point at Wenling,Zhejiang Province with a lead time of 24 and 48 h.

关键词： Typhoon Lekima(2019) track intensity landfall point forecast verification

ON GENERATING EQUATIONS FOR THE KAUP-NEWELL HIERARCHY

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Applied Mathematics(A Journal of Chinese Universities) 2007年第4期22卷 413-420页

作者： Yang zhihua zeng Yunbo Dept. of Math. Sci. Tsinghua Univ. Beijing 100084 China.

It is shown that the Kaup-Newell hierarchy can be derived from the so-called generating equations which are Lax integrable. Positive and negative flows in the hierarchy are derived simultaneously. The generating equat... 详细信息

关键词： Kaup-Newell hierarchy generating equations Lax integrable equations. Kaup-Newell hierarchy generating equations Lax integrable equations.

Measuring the Effectiveness of the Chinese Innovation System:A Global Value Chain Approach

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International Journal of Innovation Studies 2017年第1期1卷 57-71页

作者： Douglas zhihua zeng Tianjin Normal University 393 West Binshui Ave.Tianjin 300387China World Bank 1818 H St.WashingtonDC 20433USA University of International Business&Economics 10 Huixin DongjieChaoyang DistrictBeijing 100029China Xi’an Jiaotong‐Liverpool University No.111 RenʹailuSuzhouJiangsu 215123China

This paper study argues that some disruptive new trends are surfacing with the emergence of new technologies,which makes an efficient and effective R&D and innovation system even more relevant for any country to compete at a global *** this backdrop,the study tries to measure the effectiveness of the Chinese innovation system,using the“R&D spending as percentage of GDP”as the input variable and the“contribution of R&D and related business activities to the value‐added manufacturing exports”as the output *** on a 59‐country sample in the OECD‐WTO TiVA database,the regression results show a significant and positive correlation between the two *** findings also complement with other existing empirical and qualitative studies in this *** overall findings show that China has achieved significant efficiency and effectiveness in its innovation system compared with many other countries;in fact,since 2009,the efficiency has ***,it still lags behind the major global *** means China still has some room to improve in order to transform its increasing inputs in R&D and technology innovation into commensurate *** situation calls for further improvements in its innovation ecosystem.

关键词： Innovation China Global Value Chain R&D Trade

VERIFICATION OF ENSEMBLE TRACK FORECASTS OF TROPICAL CYCLONES DURING 2014

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Tropical Cyclone Research and Review 2015年第2期4卷 79-87页

作者： XIPING ZHANG GUOMIN CHEN HUI YU zhihua zeng Shanghai Typhoon Institute China Meteorological Administration

The track forecasts of fi ve ensemble prediction systems(JMA-WEPS,CMA-GEFS,ECMWF-EPS,NCEP-GEFS and MSC-CENS,respectively)in 2014 are evaluated in this ***,on the assumption of bivariate normal distribution,a probability ellipse based on ensemble spread is proposed to represent forecast uncertainties,and then the ellipse and ensemble mean are used to evaluate the fi ve different *** is found that the probability ellipse of ECMWF-EPS is smaller,with a high hit ratio,and its mean track errors are just a little larger than those of NCEP-GEFS within 48 h,meaning overall it outperforms the other four ***,the performance of CMA-GEFS is found to be the poorest.

关键词： tropical cyclone ensemble forecast track verification probability ellipse

THE PERFORMANCE OF GLOBAL MODELS IN TC TRACK FORECASTING OVER THE WESTERN NORTH PACIFIC FROM 2010 TO 2012

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Tropical Cyclone Research and Review 2013年第3期2卷 149-158页

作者： Guomin Chen Hui Yu Qing Cao zhihua zeng Shanghai Typhoon Institute China Meteorological AdministrationShanghaiChina Shanghai Marine Meteorological Center ShanghaiChina

Forecasts of tropical cyclone(TC)tracks from six global models during 2010 and 2012 were assessed to study the current capability of track forecast guidance over the western North *** measure the performance of the global model forecasts,a series of statistical evaluations of track forecasts up to 120 h were carried out,including the mean,median,percentile distribution,regional distribution,relative position,correlation analysis,and binned *** showed that certain improvements have been made for the six global models in their prediction accuracy and stability in the past three ***,stepped decreases in the values of each quantile were found at all lead time levels from 2010 to 2012 for *** analysis of the regional distribution of position errors showed that a high-latitude region,low-latitude region(which covers mostly the TC genesis region)and the South China Sea are the three main areas within which large errors tend to *** majority of the models show their own respective characteristics of systematic bias at each lead time,as established through the relative position analysis *** the results of NCEP-GFS and CMA-T639 did not show any obvious systematic bias in the three-year study *** analyses indicated that the prediction accuracy and stability of most of the models were better for strong TCs than for weak TCs at short lead time *** was also found that the models tend to perform better for initially large TCs,or for those with weak vertical wind shear at lead times shorter than 48 *** results demonstrate the heavy reliance of forecast errors upon the initial characteristics of a TC or its environmental conditions.

关键词： tropical cyclone global model track forecast verification

SECOND PHASES OF RAPIDLY SOLIDIFIED AlFeCrZrVSi ALLOY AND THEIR THERMAL STABILITIES

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Journal of Central South University 1998年第1期10卷 24-27页

作者： Xiao Yude Li Songrui Li Wenxian zeng zhihua Ma Zhengqing(Department of Materials Science and Engineering,Central South University of Technology, Changsha 410083, China) Department of Materials Science and Engineering Central South University of Technology Changsha China

The rapidly solidified powder of AlFeCrZrVSi aluminum alloy was prepared using multistage atomization and consolidated by hotextrusion, the evolution of microstructure of the extruded materials during thermal exposure was studied with optical microscope, Xray diffraction and transmission electron microscope(TEM). The results show that the majority of dispersions present in the asextruded alloy are metastable Al12(Fe, Cr, V)3Si, which has excellent thermaldynamical stability and coarsening resistance; the coarsening ratecontrolling process of the Al12(Fe, Cr, V)3Si phase is considered to be diffusion of Fe atom along grain boundaries instead of bulk diffusion of Fe atom.

关键词： aluminum alloy rapid solidification thermal stability

Research on Intrusion Data Mining Algorithm Based on Multiple Minimum Support

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Research on Intrusion Data Mining Algorithm Based on Multipl...

基于PSO算法的船舶横摇阻尼与回复力矩系数估算

作者： zeng zhihua Zhou Bing Li Cong City College Wuhan University of Science and Technology

The traditional single minimum support data mining algorithm has some problems,such as too much space occupied by data,resulting in insufficient accuracy of the algorithm,which is difficult to meet the needs of the development of the ***,an intrusion data mining algorithm based on multiple minimum support is ***,the feature parameters of frequent itemsets of intrusion data are extracted,and the sequence itemsets are divided according to the feature ***,the data mining features are transformed with the equivalent binary data transformation method,and the multisupport tree structure is optimized according to the data processing *** classification mining is carried out with the data tree structure information,and the intrusion data features are deeply ***,the research of the intrusion data mining algorithm based on the multi-minimum support is *** comparative experiments,it is proved that the accuracy of the intrusion data mining algorithm based on multiple minimum support is 35 %-75 % higher than that of the traditional single minimum support data mining algorithm.

关键词： Multiple minimum support Data mining Set function

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中国造船 2018年第3期59卷 89-97页

作者：曾智华姜宜辰邹早建上海交通大学船舶海洋与建筑工程学院上海200240 大连理工大学船舶工程学院大连116024

横摇阻尼和回复力矩的准确估算是预报船舶横摇运动的关键。论文针对横摇消灭曲线法估算横摇阻尼系数所存在的固有缺陷,提出了一种基于粒子群优化(PSO)算法,从试验得到的自由横摇衰减曲线来获取横摇阻尼和回复力矩系数的方法。该方法通... 详细信息

横摇阻尼和回复力矩的准确估算是预报船舶横摇运动的关键。论文针对横摇消灭曲线法估算横摇阻尼系数所存在的固有缺陷,提出了一种基于粒子群优化(PSO)算法,从试验得到的自由横摇衰减曲线来获取横摇阻尼和回复力矩系数的方法。该方法通过迭代调整横摇阻尼和回复力矩系数,使预报的自由横摇衰减运动时间历程与试验自由横摇衰减曲线之间的误差最小,从而实现对横摇阻尼和回复力矩系数的准确估算。

关键词：自由横摇衰减曲线 PSO算法横摇阻尼系数回复力矩系数

经济特区和产业集群如何引领中国经济高速发展

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新金融 2011年第5期 15-21页

作者：曾智华世界银行

过去30年,中国经济的飞速发展创造了人类历史上史无前例的"增长奇迹",中国改革开放后成立的经济特区以及产业集群的发展是带动中国经济增长的重要引擎。本文基于一些案例研究、专访、实地调研和大量的文献综述,简要概括中国经济特区和... 详细信息

过去30年,中国经济的飞速发展创造了人类历史上史无前例的"增长奇迹",中国改革开放后成立的经济特区以及产业集群的发展是带动中国经济增长的重要引擎。本文基于一些案例研究、专访、实地调研和大量的文献综述,简要概括中国经济特区和产业集群的发展历史、阶段特征、成功经验和持续发展所面临的挑战,并给出了相应的政策建议。

关键词：中国经济增长引擎经济特区产业集群