检索结果-南通市图书馆

Influence of Regular Wave and Ship Characteristics on Mooring Force Prediction by Data-Driven Model

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2020年第4期34卷 589-596页

作者： LIU Bi-jin CHEN Xiao-yun ZHANG You-quan XIE Jing CHANG Jiang School of Civil Engineering and Architecture Xiamen University of TechnologyXiamen 361024China fujian marine forecasts Fuzhou 350003China Tianjin Research Institute for Water Transport Engineering Tianjin 300456China Tianjin Survey and Design Institute for Water Transport Engineering Tianjin Key Laboratory of Surveying and Mapping for Waterway Transport EngineeringTianjin 300456China

The study of mooring forces is an important issue in marine engineering and offshore *** being widely applied in mooring system,numerical simulations suffer from difficulties in their multivariate and nonlinear ***-driven model is employed in this paper to predict the mooring forces in different lines,which is a new attempt to study the mooring *** height and period of regular wave,length of berth,ship load,draft and rolling period are considered as potential influencing *** variables are determined using mutual information(MI)and principal component analysis(PCA),and imported to an artificial neural network(NN)model for *** study case of 200 and 300 thousand tons ships experimental data obtained in Dalian University of Technology,MI is found to be more appropriate to provide effective input variables than *** the three factors regarding ship characteristics are highly correlated,it is recommended to input all of them to the NN *** accuracy of predicting aft spring line force attains as high as 91.2%.The present paper demonstrates the feasibility of MI-NN model in mapping the mooring forces and their influencing factors.

关键词： mooring force characteristics of ship neural network mutual information principal component analysis

A study of long-term sea level variability in the East China Sea

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2015年第11期34卷 109-117页

作者： XU Ying LIN Mingsen ZHENG Quanan YE Xiaomin LI Junyi ZHU Benlu College of Information Science and Engineering Ocean University of China National Satellite Ocean Application Service State Oceanic Administration Key Laboratory of Space Ocean Remote Sensing and Application State Oceanic Administration Department of Atmospheric and Oceanic Science University of Maryland College Park State Key Laboratory of marine Environmental Science College of Ocean & Earth Sciences Xiamen University fujian marine forecasts

From the analyses of the satellite altimeter Maps of Sea Level Anomaly （MSLA） data, tidal gauge sea level data and historical sea level data, this paper investigates the long-term sea level variability in the East China Sea （ECS）. Based on the correlation analysis, we calculate the correlation coefficient between tidal gauge and the closest MSLA grid point, then generate the map of correlation coefficient of the entire ECS. The results show that the satellite altimeter MSLA data is effective to observe coastal sea level variability. An important finding is that from map of correlation coefficient we can identify the Kuroshio. The existence of Kuroshio decreases the correlation between coastal and the Pacific sea level. Kurishio likes a barrier or a wall, which blocks the effect of the Pacific and the global change. Moreover, coastal sea level in the ECS is mainly associated with local systems rather than global change. In order to calculate the long-term sea level variability trend, the empirical mode decomposition （EMD） method is applied to derive the trend on each MSLA grid point in the entire ECS. According to the 2-D distribution of the trend and rising rate, the sea level on the right side of the axis of Kuroshio rise faster than in its left side. This result supports the barrier effect of Kuroshio in the ECS. For the entire ECS, the average sea level rose 45.0 mm between 1993 and 2010, with a rising rate of （2.5_＋0.4） mm/a which is slower than global average. The relatively slower sea level rising rate further proves that sea level rise in the ECS has less response to global change due to its own local system effect.

关键词： East China Sea sea level variability correlation analysis empirical mode decomposition

Unusual tracks:Statistical,controlling factors and model prediction

在线全文

学校读者我要写书评

暂无评论

Tropical Cyclone Research and Review 2023年第4期12卷 309-322页

作者： Ying Li Julian Heming Ryan D.Torn Shaojun Lai Yinglong Xu Xiaomeng Chen State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijingChina UK Met Office ExeterUK State University of New York New YorkUSA fujian Key Laboratory of Severe Weather FuzhouChina fujian Observatory of Pingtan marine Meteorology PingtanChina Chinese Meteorological Center BeijingChina fujian Provincial Meteorological Service Center FuzhouChina

The progress of research and forecast techniques for tropical cyclone(TC)unusual tracks(UTs)in recent years is reviewed.A major research focus has been understanding which processes contribute to the evolution of the TC and steering flow over time,especially the reasons for the sharp changes in TC motion over a short period of *** TCs are located in the vicinity of monsoon gyres,TC track forecast become more difficult to forecast due to the complex interaction between the TCs and the ***,the convection and latent heat can also feed back into the synoptic-scale features and in turn modify the steering *** this report,two cases with UTs are examined,along with an assessment of numerical model *** in numerical modelling and in particular the development of ensemble forecasting systems have proved beneficial in the prediction of such *** are still great challenges in operational track forecasts and warnings,such as the initial TC track forecast,which is based on a poor pre-genesis analysis,TC track forecasts during interaction between two or more TCs and track predictions after ***,artificial intelligence(AI)methods such as machine learning or deep learning have been widely applied in the field of TC *** TC track forecasting,a more effective method of center location is obtained by combining data from various sources and fully exploring the potential of AI,which provides more possibilities for improving TC prediction.

关键词： Unusual TC tracks Track controlling factors Track predictions Track forecast errors

Evaluation of ERA-Interim Monthly Temperature Data over the Tibetan Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2014年第5期11卷 1154-1168页

作者： GAO Lu HAO Lu CHEN Xing-wei College of Geographical Sciences Fujian Normal University fujian Provincial Engineering Research Center for Monitoring and Assessing Terrestrial Disasters Research Center for National Geographical Condition Monitoring and Emergency Support in the Economic Zone on the West Side of the Taiwan Strait College of Applied Meteorology Nanjing University of Information Science & Technology

In this study, surface air temperature from 75 meteorological stations above 3000 m on the Tibetan Plateau are applied for evaluation of the European Centre for Medium-Range Weather forecasts(ECMWF) third-generation reanalysis product ERA-Interim in the period of 1979-2010. High correlations ranging from 0.973 to 0.999 indicate that ERA-Interim could capture the annual cycle very well. However, an average root-meansquare error(rmse) of 3.7°C for all stations reveals that ERA-Interim could not be applied directly for the individual sites. The biases can be mainly attributed to the altitude differences between ERA-Interim grid points and stations. An elevation correction method based on monthly lapse rates is limited to reduce the bias for all stations. Generally, ERA-Interim captured the Plateau-Wide annual and seasonal climatologies very well. The spatial variance is highly related to the topographic features of the TP. The temperature increases significantly(10°C- 15°C) from the western to the eastern Tibetan Plateau for all seasons, in particular during winter and summer. A significant warming trend(0.49°C/decade) is found over the entire Tibetan Plateau using station time series from 1979-2010. ERA-Interim captures the annual warming trend with an increase rate of 0.33°C /decade very well. The observation data and ERA-Interim data both showed the largest warming trends in winter with values of 0.67°C/decade and 0.41°C/decade, respectively. We conclude that in general ERA-Interim captures the temperature trends very well and ERA-Interim is reliable for climate change investigation over the Tibetan Plateau under the premise of cautious interpretation.

关键词： Reanalysis Air temperature Warming trend Tibetan Plateau

Nomogram for predicting short-term response to anti-vascular endothelial growth factor treatment in neovascular age-related macular degeneration:An observational study

在线全文

学校读者我要写书评

暂无评论

World Journal of Radiology 2024年第9期16卷 418-428页

作者： Zhen-Huan Huang Xue-Zhao Tu Qi Lin Mei Tu Guo-Cai Lin Kai-Ping Zhang Department of Radiology Longyan First Affiliated Hospital of Fujian Medical UniversityLongyan 364000Fujian ProvinceChina Department of Orthopedics Longyan First Affiliated Hospital of Fujian Medical UniversityLongyan 364000Fujian ProvinceChina Department of Endocrinology Longyan First Affiliated Hospital of Fujian Medical UniversityLongyan 364000Fujian ProvinceChina Department of Ophthalmology Longyan First Affiliated Hospital of Fujian Medical UniversityLongyan 364000Fujian ProvinceChina

BACKGROUND Anti-vascular endothelial growth factor(anti-VEGF)therapy is critical for managing neovascular age-related macular degeneration(nAMD),but understanding factors influencing treatment efficacy is essential for optimizing patient *** To identify the risk factors affecting anti-VEGF treatment efficacy in nAMD and develop a predictive model for short-term *** In this study,65 eyes of exudative AMD patients after anti-VEGF treatment for≥1 mo were observed using optical coherence tomography *** were classified into non-responders(n=22)and responders(n=43).Logistic regression was used to determine independent risk factors for treatment response.A predictive model was created using the Akaike Information Criterion,and its performance was assessed with the area under the receiver operating characteristic curve,calibration curves,and decision curve analysis(DCA)with 500 bootstrap *** Multivariable logistic regression analysis identified the number of junction voxels[odds ratio=0.997,95%confidence interval(CI):0.993-0.999,P=0.010]as an independent predictor of positive anti-VEGF treatment *** predictive model incorporating the fractal dimension,number of junction voxels,and longest shortest path,achieved an area under the curve of 0.753(95%CI:0.622-0.873).Calibration curves confirmed a high agreement between predicted and actual outcomes,and DCA validated the model's clinical *** The predictive model effectively forecasts 1-mo therapeutic outcomes for nAMD patients undergoing anti-VEGF therapy,enhancing personalized treatment planning.

关键词： Vascular endothelial growth factor Macular degeneration Neovascularization Age-related macular degeneration Choroidal neovascularization Optical coherence tomography angiography Nomogram

Multi-Source Data Analyses of Processes of a Squall Line and the Gale Weather with Heavy Hails before the Squall Line

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geoscience and Environment Protection 2017年第8期5卷 27-40页

作者： Meijin Huang Minyan Chen Ning Pan Jinqin Feng Huiying Yue fujian Provincial Meteorological Observatory Fuzhou China Longyan City fujian Provincial Meteorological Bureau Longyan China

Through multi-source data analyses of regional automatic station data, wind profiling radar, lightning information, new-generation weather-radar echo data and conventional observations in fujian Province, and others, this paper finds out aspects to focus on for potential forecasts and the nowcasting of wide-range gale weathers with thunderstorms and hail weathers in west fujian Province on April 26th, 2016. Thus providing a basis for future forecasting of such catastrophic meteorological activities. Results of analyses showed that being affected by the eastward moving of upper troughs and the eastward and southward moving of low-level vortex shears, cold air and warm air strongly intersected in west fujian Province;noticeable cold and warm advection formed the temperature frontal-zone;and under the triggering of the ground convergence line, impetuses formed by the strong convergent uplift before the south troughs forcibly produced wide-range squall lines, hails and other strong convective weathers. The squall line was caused by baroclinic frontogenesis. Hails with a diameter of up to 3 cm happened in the prefrontal warm zone. Supercells were generated and developed in the 80 km hot low-pressure convergence zone before the squall line moved along the direction at about 25° to the right of the mean wind field of the environment, belonged to right-shifting hailstorms, were of characteristics representing the hook echo and were of characteristics that the strength of the echo was high. On the afternoon of 26th, on the ground, temperature and humidity strongly increased. fujian was located in the warm zone in the south side of the inverted trough. The specific humidity at 850 hPa was higher than 12 g/kg. The positive temperature change lasted for 24 hours. In the inland, the ridge was warm, while the trough was cold. Strong vertical wind shears that reached 20 m/s at 925 - 500 hPa and others were beneficial environmental conditions for forming the process of strong conve

关键词： Hailing before the Squall Temperature Frontal-Zone Wind Profiling Radar Vertical Wind Shears Supercell Storms

Impacts of Increasing Model Resolutions and Shortening Forecast Lead Times on QPFs in South China During the Rainy Season

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Tropical Meteorology 2023年第3期29卷 277-300页

作者：张旭斌李静珊罗亚丽宝兴华陈靖扬肖辉文秋实 Guangzhou Institute of Tropical and marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction CMAGuangzhou 510641 China Guangdong Ecological Meteorology Centre(Pearl River Delta Center for Environmental Meteorology Prediction and Warning) Guangzhou 510640 China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters&School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044 China fujian Key Laboratory of Severe Weather&Key Laboratory of Straits Severe Weather CMAFuzhou 350007 China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081 China Guangzhou Institute of Tropical and marine Meteorology CMAGuangzhou 510641 China

This study investigated the impacts of increasing model resolutions and shortening forecast lead times on the quantitative precipitation forecast(QPF)for heavy-rainfall events over south China during the rainy seasons in *** control experiment,where the analysis-forecast cycles run with model resolutions of about 3 km,was compared to a lower-resolution experiment with model resolutions of about 9 km,and a longer-term experiment activated 12 hours *** forecasting in the presummer rainy season was significantly improved by improving model resolutions,with more improvements in cases with stronger synoptic-scale *** is partially attributed to the improved initial conditions(ICs)and subsequent forecasts for low-level jets(LLJs).forecasts of heavy rainfall induced by landfalling tropical cyclones(TCs)benefited from increasing model resolutions in the first 6 *** improvements in rainfall due to shortening forecast lead times were more significant at earlier(1-6 h)and later(7-12 h)lead times for cases with stronger and weaker synoptic-scale forcings,respectively,due to the area-and case-dependent improvements in ICs for nonprecipitation ***,significant improvements mainly presented over the northern South China Sea for low-level onshore wind of weak-forcing cases but over south China for LLJs of strong-forcing cases during the presummer rainy season,and over south China for all the nonprecipitation variables above the surface during the TC ***,some disadvantages of higher-resolution and shorter-term forecasts in QPFs highlight the importance of developing ensemble forecasting with proper IC perturbations,which include the complementary advantages of lower-resolution and longer-term forecasts.

关键词： south China QPF model resolution forecast lead time

The Relationship between Deterministic and Ensemble Mean Forecast Errors Revealed by Global and Local Attractor Radii

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2019年第3期36卷 271-278,339页

作者： Jie FENG Jianping LI Jing ZHANG Deqiang LIU Ruiqiang DING School of Meteorology University of Oklahoma College of Global Change and Earth System Science (GCESS) Beijing Normal University Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Cooperative Institute for Research in the Atmosphere GSD/ESRL/OAR/NOAA fujian Meteorological Observatory Wuyishan National Park Meteorological Observatory State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information Technology

It has been demonstrated that ensemble mean forecasts, in the context of the sample mean, have higher forecasting skill than deterministic(or single) forecasts. However, few studies have focused on quantifying the relationship between their forecast errors, especially in individual prediction cases. Clarification of the characteristics of deterministic and ensemble mean forecasts from the perspective of attractors of dynamical systems has also rarely been involved. In this paper, two attractor statistics—namely, the global and local attractor radii(GAR and LAR, respectively)—are applied to reveal the relationship between deterministic and ensemble mean forecast errors. The practical forecast experiments are implemented in a perfect model scenario with the Lorenz96 model as the numerical results for verification. The sample mean errors of deterministic and ensemble mean forecasts can be expressed by GAR and LAR, respectively, and their ratio is found to approach2^(1/2) with lead time. Meanwhile, the LAR can provide the expected ratio of the ensemble mean and deterministic forecast errors in individual cases.

关键词： attractor radius ensemble forecasting ensemble mean forecast error saturation

A Logistic-growth-equation-based Intensity Prediction Scheme for Western North Pacific Tropical Cyclones

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2021年第10期38卷 1750-1762页

作者： Yanchen ZHOU Jiuwei ZHAO Ruifen ZHAN Peiyan CHEN Zhiwei WU Lan WANG Department of Atmospheric and Ocean Sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China fujian Key Laboratory of Severe Weather Fuzhou 350001China Shanghai Typhoon Institute of China Meteorological Administration Shanghai 200030China Big Data Institute for Carbon Emission and Environmental Pollution Fudan UniversityShanghai 200438China

Accurate prediction of tropical cyclone(TC)intensity remains a challenge due to the complex physical processes involved in TC intensity changes.A seven-day TC intensity prediction scheme based on the logistic growth equation(LGE)for the western North Pacific(WNP)has been developed using the observed and reanalysis *** the LGE,TC intensity change is determined by a growth term and a decay *** two terms are comprised of four free parameters which include a time-dependent growth rate,a maximum potential intensity(MPI),and two *** 33 years of training samples,optimal predictors are selected first,and then the two constants are determined based on the least square method,forcing the regressed growth rate from the optimal predictors to be as close to the observed as *** estimation of the growth rate is further refined based on a step-wise regression(SWR)method and a machine learning(ML)method for the period 1982−*** the LGE-based scheme,a total of 80 TCs during 2015−17 are used to make independent *** show that the root mean square errors of the LGE-based scheme are much smaller than those of the official intensity forecasts from the China Meteorological Administration(CMA),especially for TCs in the coastal regions of East ***,the scheme based on ML demonstrates better forecast skill than that based on *** new prediction scheme offers strong potential for both improving the forecasts for rapid intensification and weakening of TCs as well as for extending the 5-day forecasts currently issued by the CMA to 7-day forecasts.

关键词： tropical cyclone intensity prediction western North Pacific logistic growth equation