辅助模型辨识方法(4):基本思想与梯度辨识     

丁锋 《南京气象学院学报》2016,8(4):289-309

辅助模型辨识思想是针对系统存在一些不可测变量的辨识问题提出的,它是研究含有未知变量的线性系统、非线性系统辨识的重要手段.本文阐述了辅助模型辨识思想,针对白噪声干扰的输入非线性有限脉冲响应系统,研究辅助模型梯度辨识方法、辅助模型多新息梯度辨识方法、变递推间隔辅助模型多新息梯度辨识方法,以及派生的变递推间隔辅助模型梯度辨识方法、等递推间隔辅助模型梯度辨识方法和等递推间隔辅助模型多新息梯度辨识方法.  相似文献   

东北冷涡降水集中期的客观识别研究   总被引：2，自引：1，他引：1  

房一禾  龚志强  陈海山 《气象》2016,42(1):80-88

基于区域关键天气过程客观化识别和监测的需求及东北雨季应包括冷涡降水的事实,采用东北三省及内蒙古东四盟共147站逐日降水量资料,通过对东北区域多年平均5点平滑处理的逐日降水量序列的综合分析及对历年逐日滑动平均雨量的对比试验,确定了判别东北冷涡降水集中期开始日期的阈值及持续时间,进而研制了东北冷涡降水集中期开始日期的客观识别方法。基于该方法的客观识别,得到1981-2010年气候平均态的东北冷涡降水集中期的开始日期为每年的5月26日。同时,定义盛夏降水集中期开始日的前一日为冷涡降水集中期的结束日期,发现冷涡降水集中期的结束日期为6月25日。在此基础上,采用NCEP/NCAR逐日再分析的风场、位势高度场资料,通过对东北冷涡降水集中期前、中和后期各层大气环流场及各系统的逐日变化特征的对比分析,验证了该客观识别方法的合理性。  相似文献   

卫星遥感云分类和TBB产品在天津地区云状识别的应用分析     

刘一玮  孙建元  王颖  何群英 《气象》2016,42(8):980-986

利用2012年4月1日至2013年7月31日地面观测资料和卫星遥感云分类、相当黑体亮温TBB产品,针对不同天气类型进行背景统计和个例分析,讨论云分类、TBB产品在云状自动识别中的应用。结果表明:地面云观测取消后,云观测业务可以依据卫星遥感产品展开,即以云分类产品为基础,结合TBB资料和天气现象进行订正。当无降水时,云状以云分类产品为主,如云分类产品为积雨云,可将云状订正为非降水云;当TBB240 K时,同时变率由负值向正值转变至接近0时,有雷暴活动发生,无论是何种云分类产品,云状可直接定为积雨云;TBB在240~260 K,为稳定性降水时,考虑为非对流性云(层积云或高积云、高层云或雨层云)。  相似文献   

A building extraction approach for Airborne Laser Scanner data utilizing the Object Based Image Analysis paradigm     

《International Journal of Applied Earth Observation and Geoinformation》2016

In the past two decades Object-Based Image Analysis (OBIA) established itself as an efficient approach for the classification and extraction of information from remote sensing imagery and, increasingly, from non-image based sources such as Airborne Laser Scanner (ALS) point clouds. ALS data is represented in the form of a point cloud with recorded multiple returns and intensities. In our work, we combined OBIA with ALS point cloud data in order to identify and extract buildings as 2D polygons representing roof outlines in a top down mapping approach. We performed rasterization of the ALS data into a height raster for the purpose of the generation of a Digital Surface Model (DSM) and a derived Digital Elevation Model (DEM). Further objects were generated in conjunction with point statistics from the linked point cloud. With the use of class modelling methods, we generated the final target class of objects representing buildings. The approach was developed for a test area in Biberach an der Riß (Germany). In order to point out the possibilities of the adaptation-free transferability to another data set, the algorithm has been applied “as is” to the ISPRS Benchmarking data set of Toronto (Canada). The obtained results show high accuracies for the initial study area (thematic accuracies of around 98%, geometric accuracy of above 80%). The very high performance within the ISPRS Benchmark without any modification of the algorithm and without any adaptation of parameters is particularly noteworthy.  相似文献   

混沌时间序列相空间重构及特性识别     

张艳兰  栾元重  尹燕运  郭喜田  桑春阳  杜玉喜 《测绘科学》2016,41(4):15-18

相空间重构是混沌时间序列分析及预测的前提。针对地铁建设中地表沉降变形监测的弱信号数据处理问题,该文引入了混沌理论,通过采用自相关函数法和C-C法对比求得时间延迟τ,运用G-P方法和Cao方法求取嵌入维数m,从而对时间序列进行相空间重构;并通过求取最大Lvyapunov指数对时间序列进行混沌特性的判定识别。研究结论表明,系统的混沌特性,在研究地铁变形监测、运用混沌理论建模预测以及变形监测数据处理方面是值得重视的。  相似文献   

斑点叉尾鮰(Ictalunes punctatus)源中间气单胞菌(Aeromonas media)分离鉴定及药敏特性     

杨移斌  杨秋红  胥宁  董靖  刘永涛  艾晓辉 《海洋与湖沼》2016,47(6):1199-1204

从湖南常德某养殖场死亡的斑点叉尾（Ictalunes punctatus）肝脏、肾脏、腹水及血水中分离到一株致病性菌株zy02。对该菌进行了形态特征观察、理化特性测定及分子生物学方法鉴定,用PCR方法同时扩增其16S rDNA和gyrB基因,分析了16S rDNA和gyrB两种基因序列的同源性,并构建了系统发生树。经生理生化测定和16S rDNA与gyrB基因序列分析,zy02株为中间气单胞菌。人工感染该菌后发病鱼表现为与自然发病类似症状,且从组织中再分离的细菌特性与原感染菌相同。腹腔注射后该菌株对斑点叉尾的半致死浓度为3.89×10⁶CFU/mL。菌株zy02对多西环素、庆大霉素及左氧氟沙星等高度敏感;对红霉素中度敏感;对阿莫西林、磺胺异噁唑、克林霉素及利福平等5种药物耐药。本研究为斑点叉尾该病防控提供了理论依据。  相似文献   

A computer method based on simulated annealing to identify aquifer parameters using pumping‐test data     

Yen‐Chen Huang  Hund‐Der Yeh  Yu‐Chung Lin 《国际地质力学数值与分析法杂志》2008,32(3):235-249

Conventional graphical or computer methods for identifying aquifer parameters have their own inevitable limitations. This paper proposes a computer method based on a drawdown model and a heuristic approach of simulated annealing (SA) to determine the best‐fit aquifer parameters of the confined and unconfined aquifer systems. The drawdown model for the confined aquifer is the Theis solution and the unconfined aquifer is the Neuman solution. The estimated results of proposed method have better accuracy than those of the graphical methods and agree well with those of the computer methods based on the extended Kalman filter and Newton's method. Finally, the sensitivity analyses for the control parameters of SA indicate that the proposed method is very robust and stable in parameter identification procedures. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Identification of marine natural gases with different origin sources     

《中国科学D辑(英文版)》2008,(Z1)

Kinetic experiments of gas generation for typical samples of marine gas precursors including low-maturity kerogen,residual kerogen and oil as well as dispersed liquid hydrocarbon(DLH)in source rocks were performed by closed system,and the evolution trends of molecular and isotopic compositions of natural gases from different precursors against the maturity(R0%)at laboratory conditions were analyzed.Several diagrams of gas origin were calibrated by using the experimental data.A diagram based on the ratio of normal and isomerous butane and pentane(i/nC4-i/nC5)was proposed and used to identify the origins of the typical marine natural gases in the Sichuan Basin and the Tarim Basin, China.And the maturities of natural gases were estimated by using the statistical relationships between the gaseous molecular carbon isotopic data and maturities(δ13C-R 0 %)with different origins.The results indicate that the molecular and isotopic compositions of simulated gases from different precursors are different from each other.For example,the dryness index of the oil-cracking gas is the lowest;the dryness indices of gases from DLH and kerogen in closed system are almost the same;and the dryness index of gases from residual kerogen is extremely high,indicating that the kerogen gases are very dry;the contents of non-hydrocarbon gases in kerogen-cracking gases are far higher than those in oil-cracking and DLH-cracking gases.The molecular carbon isotopes of oil-cracking gases are the lightest,those of kerogen in closed system and GLH-cracking gases are the second lightest,and those of cracking gases from residual kerogen are the heaviest.The calibration results indicate that the diagrams of ln(C1/C2)-ln(C2/C3)andδ13C2-δ13C3-ln(C2/C3)can discriminate primary and secondary cracking gases,but cannot be used to identify gas origin sources,while the diagram of i/nC4-i/nC5 can differentiate the gases from different precursors.The application results of these diagrams show that gas mixtures extensively exist in China,which involved the gases from multiple precursors and those from different maturity stages.For example,marine gases in the Sichuan Basin involve the mixture of oil-cracking gases and high-over-maturated kerogen gases,while those in the Tarim Basin involve not only the mixture of gases from multiple precursors,but also those from different maturity gases and post-reservoir alternations such as oxidized degradation and gas intrusion processes.  相似文献   

地震低频伴影的数值模拟与应用   总被引：11，自引：2，他引：9  

贺振华  熊晓军  边立恩 《应用地球物理》2008,5(4):301-306

Strong low-frequency energy beneath a hydrocarbon reservoir is called a seismic low-frequency shadow and can be used as a hydrocarbon indicator （Tarter et al., 1979） bu the physical mechanism of the observed low-frequency shadow is still unclear. To stud） the mechanism, we performed seismic numerical simulation of geological models with a hydrocarbon-bearing zone using the 2-D diffusive-viscous wave equation which car effectively model the characteristics of velocity dispersion and transform the seismic dat~ centered in a target layer slice within a time window to the time-frequency domain by usinl time-frequency signal analysis and sort the frequency gathers to common frequency cubes. Then, we observe the characteristics of the seismic low-frequency shadow in the common frequency cubes. The numerical simulations reveal that the main mechanism of seismic lowfrequency shadows is attributed to high attenuation of the medium to high seismic frequency components caused by absorption in the hydrocarbon-filled reservoir. Results from a practical example of seismic low-frequency shadows show that it is possible to identify the reservoir by the low-frequency shadow with high S/N seismic data.  相似文献   

高心墙土石坝坝料流变模型参数的智能识别研究     

吴晓玲  肖海斌  周辉 《岩土力学》2008,29(3):614-618

通过在遗传算法中引入位爬山法,有效地改善了遗传算法的局部优化能力,提高了其优化速度与精度。采用这一改进的遗传算法对糯扎渡水电站心墙土石坝坝料流变模型参数进行了大范围识别,实现了参数空间内全局意义上的快速搜索。对取自不同坑号的各种坝料进行了流变参数识别,识别结果较准确地反映了不同应力水平下坝料的流变特征,拟合精度较高。结果表明：不同坑号的坝料在力学特性上各有差异,为了全面了解各种坝料的流变特性,对不同料场的坝料进行试验研究是有必要的;同时,不同应力状态下坝料的流变力学参数有差异,说明不同围压对坝料结构的改变也不同,从而对其流变特征的影响也会有差异。  相似文献