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利用多级变量分型法作濮阳6~8月份暴雨48h预报
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作者 张明捷 徐巧真 《河南气象》 1996年第3期10-10,共1页
暴雨是一种中尺度现象.因其尺度小、突发性强、临界参数不明显,增加了预报的难度.形成暴雨的物理条件虽然只有两个.即强烈垂直上升运动和源源不断的水汽输送,但同时具备这两个条件的天气形势和影响系统确实是非常复杂的.常见的预报方法... 暴雨是一种中尺度现象.因其尺度小、突发性强、临界参数不明显,增加了预报的难度.形成暴雨的物理条件虽然只有两个.即强烈垂直上升运动和源源不断的水汽输送,但同时具备这两个条件的天气形势和影响系统确实是非常复杂的.常见的预报方法所用资料都是原始资料,而本方法所用二级变量、三级变量(二级变量是当天24h变高减去前一天24h变高;三级变量是当天二级变量减去前一天二级变量)是原始资料加工出来的.前者是各种系统静态和整体的反映,后者是局部的动态反映. 展开更多
关键词 暴雨 降水预报 多级变量分型
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油桶盖座注射模设计
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作者 吴光明 《模具工业》 1999年第12期35-36,共2页
介绍了食用油桶盖座注射模设计中所采用的多级分型、二次顶出、先复位等机构。
关键词 强制脱模 多级分型 先复位 油桶盖 注射模
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A Multiple Model Approach to Modeling Based on Fuzzy Support Vector Machines 被引量:2
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作者 冯瑞 张艳珠 +1 位作者 宋春林 邵惠鹤 《Journal of Shanghai Jiaotong university(Science)》 EI 2003年第2期137-141,共5页
A new multiple models(MM) approach was proposed to model complex industrial process by using Fuzzy Support Vector Machines(F -SVMs). By applying the proposed approach to a pH neutralization titration experiment, F -SV... A new multiple models(MM) approach was proposed to model complex industrial process by using Fuzzy Support Vector Machines(F -SVMs). By applying the proposed approach to a pH neutralization titration experiment, F -SVMs MM not only provides satisfactory approximation and generalization property, but also achieves superior performance to USOCPN multiple modeling method and single modeling method based on standard SVMs. 展开更多
关键词 fuzzy support vector machines(FSVMs) fuzzy support vector classifier(FSVC) fuzzy support vector regression(FSVR) multiple model MODELING
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Development of Multilevel Meteorological Data Acquisition System for Radiation Emergency Decision Support
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作者 D.N. Krishnakumar A. Bagavath Singh Anjukumari R. Baskaran M.T. Jose B. Venkatraman 《Journal of Earth Science and Engineering》 2013年第8期545-553,共9页
This paper describes a development of multilevel meteorological data acquisition system implemented at Kalpakkam coastal site for atmospheric dispersion and model validation studies. Meteorological data are one of the... This paper describes a development of multilevel meteorological data acquisition system implemented at Kalpakkam coastal site for atmospheric dispersion and model validation studies. Meteorological data are one of the most important inputs into any air dispersion model. As a part of atmospheric dispersion modeling studies and developing a methodology to forecast the site-specific dispersion characteristics, the real time monitoring of meteorological parameters assumes significance. This is achieved by erecting met towers instrumented at multilevel and single level at different locations with sensors for measuring various meteorological parameters. Real-world data logging applications involve not only just acquiring and recording signals, but also combination of offline analysis, display, report generation and data sharing. This paper covers development of low cost compact MMDAS (modular meteorological data acquisition system), its performance evaluation, field deployment test and data comparison analysis with fast response and high accuracy internationally acclaimed sonic anemometer. The system is based on embedded modules from Advantech and is designed to acquire analogue and digital signals from a multilevel instrumented met tower. The collected data are transferred from remote base station to central server for storage and further processing using wireless interface. MMDAS has many advantages like cost effectiveness, less complex signal conditioning electronics and easy maintenance. This system has good application during radiation emergency as well as site specific meteorological data collection and model validation studies. 展开更多
关键词 Radiation emergency meteorological data acquisition MMDAS dispersion modeling sonic anemometer.
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MF~2ResU-Net:a multi-feature fusion deep learning architecture for retinal blood vessel segmentation
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作者 CUI Zhenchao SONG Shujie QI Jing 《Digital Chinese Medicine》 2022年第4期406-418,共13页
Objective For computer-aided Chinese medical diagnosis and aiming at the problem of insufficient segmentation,a novel multi-level method based on the multi-scale fusion residual neural network(MF2ResU-Net)model is pro... Objective For computer-aided Chinese medical diagnosis and aiming at the problem of insufficient segmentation,a novel multi-level method based on the multi-scale fusion residual neural network(MF2ResU-Net)model is proposed.Methods To obtain refined features of retinal blood vessels,three cascade connected UNet networks are employed.To deal with the problem of difference between the parts of encoder and decoder,in MF2ResU-Net,shortcut connections are used to combine the encoder and decoder layers in the blocks.To refine the feature of segmentation,atrous spatial pyramid pooling(ASPP)is embedded to achieve multi-scale features for the final segmentation networks.Results The MF2ResU-Net was superior to the existing methods on the criteria of sensitivity(Sen),specificity(Spe),accuracy(ACC),and area under curve(AUC),the values of which are 0.8013 and 0.8102,0.9842 and 0.9809,0.9700 and 0.9776,and 0.9797 and 0.9837,respectively for DRIVE and CHASE DB1.The results of experiments demonstrated the effectiveness and robustness of the model in the segmentation of complex curvature and small blood vessels.Conclusion Based on residual connections and multi-feature fusion,the proposed method can obtain accurate segmentation of retinal blood vessels by refining the segmentation features,which can provide another diagnosis method for computer-aided Chinese medical diagnosis. 展开更多
关键词 Medical image processing Atrous space pyramid pooling(ASPP) Residual neural network Multi-level model Retinal vessels segmentation
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2019-2020年河北省百日咳鲍特菌分离株基因多样性分析
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作者 贾肇一 郑飞 +7 位作者 张洪斌 王乐雨 张海霞 张文超 段素霞 王若璇 孙印旗 何宝花 《中国疫苗和免疫》 CSCD 北大核心 2024年第4期415-420,共6页
目的分析河北省百日咳鲍特菌(Bordetella pertussis,Bp)分离株基因多样性。方法对2019-2020年河北省儿童医院分离的Bp流行株进行二代全基因组测序和组装拼接获得全基因组序列,进行多位点序列分型(Multilocus sequence typing,MLST)、多... 目的分析河北省百日咳鲍特菌(Bordetella pertussis,Bp)分离株基因多样性。方法对2019-2020年河北省儿童医院分离的Bp流行株进行二代全基因组测序和组装拼接获得全基因组序列,进行多位点序列分型(Multilocus sequence typing,MLST)、多位点抗原序列分型(Multilocus antigen sequence typing,MAST)、多级基因组分型(Multilevel genome typing,MGT)、Bp疫苗抗原序列分型(Bordetella pertussis vaccine antigens sequence typing,BPagST)和23S rRNA基因突变分析。结果在62株Bp分离株中,MLST均为ST-2型,56株携带ptxP1基因的分离株与疫苗株相比发生23S rRNA A2047G突变(其中6株属于Prn基因缺陷型),6株携带ptxP3基因的Bp菌株未发生该突变;MAST包括6种型别,主要为prn1/ptxP1/ptxA1/fim3-1/fim2-1(47株);MGT在MGT1至MGT5水平上分别包括1种、2种、3种、14种和52种型别;BPagST包括BPagST-37型(56株)和BPagST-4型(6株)。结论本研究Bp分离株与疫苗株相比主要毒力蛋白基因和核心基因组发生明显变化,可能导致BP流行株发生疫苗免疫逃逸。需进一步加强Bp流行株基因组监测。 展开更多
关键词 百日咳 百日咳鲍特菌 基因型 多位点序列分型 多位点抗原序列分型 多级基因组分型 百日咳鲍特菌疫苗抗原序列分型
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