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The Evaluation Method of Road Traffic Safety Based on the Combined principal component Cluster Analysis

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The Evaluation Method of Road Traffic Safety Based on the Co...

Structural Damage Detection Method Based on Decomposition of the Operating Deflection Shapes

2011 International Conference on Business Management and Electronic Information(BMEI 2011)

作者： Liying Wei Jian Sun School of Traffic and Transportation Beijing Jiaotong University Beijing China

On purpose of scientifically and reasonably evaluating the present state of traffic safety,the improved principal component analysis and Cluster analysis are combined and the deficiency of existence of negative variation coefficient in principal component analysis could be made up by value assignment *** of all,the synthesis evaluation indicators system is constructed based on nine relative indicators such as mortality rate per ten thousand vehicles,injury rate per ten thousand vehicles,mortality rate per million people,injury rate per million people,crash frequency per mile,extra serious accident frequency per mile and so on,which could comprehensively reflect the safety of road ***,the data from the eastern provinces of China in 2009 are synthetically evaluated step by step as an example by applying the traditional and improved principal component analysis ***,the evaluation results are compared and analyzed according to the differences between these two methods by the Cluster analysis method.

关键词： principal component variation coefficient comprehensive evaluation indicator cluster analysis

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Chinese Journal of Mechanical Engineering 2011年第3期24卷 480-486页

作者： ZANG Chaoping College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Full-field measurement techniques such as the scanning laser Doppler vibrometer （LDV） and the electronic speckle pattern interferometry systems can provide a dense and accurate vibration measurement on structural operating deflection shape （ODS） on a relatively short period of *** possibility of structural damage detection and localization using the ODS looks likely more attractive than when using traditional measurement techniques which address only a small number of discrete *** paper discusses the decomposition method of the structural ODSs in the time history using principal component analysis to provide a novel approach to the structural health monitoring and damage *** damage indicator is proposed through comparison of structural singular vectors of the ODS variation matrixes between the healthy and damaged stages.A plate piece with a fix-free configuration is used as an example to demonstrate the effectiveness of the damage detection and localization using the proposed *** simulation results show that：（1） the dominated principal components and the corresponding singular vectors obtained from the decomposition of the structural ODSs maintain most of all vibration information of the plate,especially in the case of harmonic force excitations that the 1st principal component and its vectors mostly dominated in the system;（2） the damage indicator can apparently flag out the damage localization in the case of the different sinusoidal excitation frequencies that may not be close to any of structural natural *** successful simulation indicates that the proposed method for structural damage detection is novel and *** also indicates the potentially practical applications in industries.

关键词： damage detection decomposition operating deflection shape (ODS) principal component

Ozone Profile Retrieval from Satellite Observation Using High Spectral Resolution Infrared Sounding Instrument

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Advances in Atmospheric Sciences 2001年第5期18卷 959-971页

作者： Yanni Qu, Mitchell D. Goldberg and Murty Divakarla Research and Data System Corporation, 7833 Walker Dr Greenbelt. MD 20770 National Eivironment Satellite Data and Information Service, Office of Research and Application, World Weather Building. 5200 Auth Research and Data System Corporation Greenbelt USA National Environment Satellite Data and Information Service Office of Research and Application Camp Springs USA

This paper presents a preliminary result on the retrieval of atmospheric ozone profiles using an im- proved regression technique and utilizing the data from the Atmospheric InfraRed Sounder (AIRS), a hyper-spectral Instrument expected to be flown on the EOS-AQUA platform in 20D2. Simulated AIRS spectra were used to study the sensitivity of AIRS radiance on the tropospheric and stratospheric ozone changes, and to study the impact of various channel combinations on the ozone profile retrieval. Sensitivity study results indicate that the AIRS high resolution spectral channels between the wavenumber 650- 800 cm-1 provide very useful information to accurately retrieve tropospheric and stratospheric ozone pro- files Eigenvector decomposition of AIRS spectra indicate that no more than 100 eigenvectors are needed to retrieve very accurate ozone profiles. The accuracy of the retrieved atmospheric ozone profile from the pres- ent technique and utilizing the AIRS data was compared with the accuracy obtained from current Advanced TIROS Operational Vertical Sounder (ATOVS) data aboard National Oceanic and Atmospheric Admini- stration (NOAA) satellites As expected, a comparison of retrieval results confirms that the ozone profile re- trieved with the AIRS data is superior to that of ATOVS

关键词： AIRS ATOVS Regression Eigenvector principal component

Changes and spatial patterns of the differences between ground and air temperature over the Qinghai-Xizang Plateau

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Journal of Geographical Sciences 2007年第1期17卷 20-32页

作者： ZHANG Wengang LI Shuxun WU Tonghua PANG Qiangqiang The National Field Station for Scientific Observation of Cryosphere Special Environment and Disaster over the North of Qinghai-Tibet Plateau Golmud 816000 China Cold and Arid Regions Environmental and Engineering Research Institute CAS Lanzhou 730000 China

The difference between ground soil and air temperature （Ts-Ta） was studied by using the data of ground and air temperature of 99 stations over the Qinghai-Xizang （Tibet） Plateau from 1960 to 2000,and its spatial distribution and time changing tendency have been diagnosed by principal component analysis and power spectral analysis methods. The results show that the values of （Ts-Ta） are the maximum in June and the minimum in December. The first three loading eigenvectors, which reflect the main spatially anomalous structure of （Ts-Ta） over the Qinghai-Xizang Plateau, contain the contrary changing pattern between the northwestern and the southeastern regions, the pattern response of the sea level elevation and the geography, and the pattern response of the distribution of the permafrost. There are four patterns of time evolution including the patterns of monotonous increasing or decreasing trends, the basic stability pattern and the parabola pattern with the minimum value. （Ts-Ta） has a periodic variation about 2 years. According to the spatial distribution of the third loading eigenvectors of （Ts-Ta） over the Qinghai-Xizang Plateau in cold season, the permafrost response region and the seasonal frozen ground response region are identified.

关键词： Qinghai-Xizang Plateau difference between ground and air temperature (Ts-Ta) principal component temperature subarea

Evaluation of Candidate Predictors for Seasonal Precipitation Forecasting

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Atmospheric and Climate Sciences 2023年第4期13卷 539-564页

作者： Pedro M. González-Jardines Maibys Sierra-Lorenzo Adrián L. Ferrer-Hernández Arnoldo Bezanilla-Morlot Center for Atmospheric Physics Institute of Meteorology Havana Cuba

This research proposes to carry out a principal component analysis using the maximum covariance method, with the aim of finding the most robust spatio-temporal relationships between several candidate predictors and the accumulated monthly precipitation recorded in Cuba during the period 1980-2020. This process will make it possible to establish quantitative relationships that, together with theoretical considerations, make it possible to reduce the list of predictors to be used for the purpose of obtaining seasonal predictions. The values of the predictors are represented through monthly averages obtained from ERA5 reanalysis, while monthly accumulated precipitation data were obtained from a national-scope grid with 4 km of spatial resolution, used as predictand. The results obtained reflect the highest spatio-temporal correlation values with the first variability mode in all cases, indicating that the usual regime conditions are predominant and have a greater coupling with the precipitation variability in the analyzed temporal scale. In addition, they suggest that the candidates that explain the transport of moisture at low levels, as well as the gradients between the middle and lower troposphere, show the most robust associations. In the same way, the surface temperature of tropical Atlantic Sea, the flow related to Quasi-Biennial Oscillation and the thermodynamic indices, K Index and Galvez-Davison Index, present good degrees of association, for which reason they can be considered the most recommendable for carrying out forecasting experiments.

关键词： principal component Maximun Covariance Predictors ERA5

The Diagenesis of Plant Lipids during the Formation of the Krepoljin Coal Basin(Serbia)—Using Multivariate Statistical Analysis in the Saturated Biomarkers

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Acta Geologica Sinica(English Edition) 2008年第6期82卷 1168-1178页

作者： Gordana DEVI Branimir JOVANIEVI Center of Chemistry IChTMNjegoeva 1211000 BelgradeSerbia Faculty of Chemistry University of BelgradePOB 15811001 BelgradeSerbia

The composition of the saturated hydrocarbon fraction of soluble organic matter （bitumen） from the Krepoljin brown coal basin （East Serbia） of Miocene age was investigated. The Krepoljin basin is especially interesting from a geochemical point of view. Namely, by the end of Tertiary Period, the basin was covered by powerful Mesozoic formations of great possibilities, the bedding became hermetically enclosed and protected from subsequent external influences. The nature of early diagenetic processes in the environment with abundant accumulation of organic substance is defined by the molecular content of bitumen through the connections of molecular structures to potential precursors in paleoplant phylla, as well as by the degree of their diagenetic transformations. The hierarchy of parameters based on molecules of saturated hydrocarbons was determined by applying the principal component analysis to the soluble organic matter. The most significant, most ＂loadings＂ values of component CI, are the plant types such as precursors or participants in early diagenetic transformations of steranes Cs27-algal precursor material, Cs28-moulds, Cs29-higher land and water plants; resinous from the group of higher plant gymnosperms （G）; also triterpanes a and β-amirindicotyledonous angiosperms （A） and bacterial and/or terrestrial plants population represented by hopanes/moretanes; as well as the parameters which describe the degree of diagenetic/maturation transformation of precursor biomass, and based on next reactions：（1） shifting of methyl group, influenced by the inorganic sediment constitutents, sterane-rearranged steranes, （2） isomerization in the ring system, ααα→βββ C29 sterane as well as （3） isomerization on chiral center of the side chain sequence R→S C29 sterane S/（S＋R）. Additionally, a pyrite-derived inhibitory effect on the rearrangment of C29 steranes must be taken into account, but not on triterpanes reaction. Non- appearance of statistically important correlations, be

关键词： brown coal diagenetic transformations of saturated biomarkers diagenetic transformations of saturated biomarkers steranes diterpanes and triterpanes principal component

Detection and assessment of nitrogen effect on cold tolerance for tea by hyperspectral reflectance with PLSR, PCR, and LM models

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Information Processing in Agriculture 2021年第1期8卷 96-104页

作者： Eric Amoah Asante Zhe Du Yongzong Lu Yongguang Hu School of Agricultural Equipment Engineering Institute of Agricultural EngineeringJiangsu UniversityZhenjiangJiangsu 212013China Department of Mechanical Engineering Faculty of EngineeringKoforidua Technical UniversityKoforiduaGhana

Knowledge of nutrients effect on freezing tolerance is vital for protecting tea plants against cold injury(CI).Freezing injury treatments on tea leaves with different low temperature and nitrogen(N)concentration was evaluated by hyperspectral imaging based on the reflectance as potential analytical ***,quantitative evaluation of the CI was improved by comparing analyzed results using partial least squares regression(PLSR),principle component regression(PCR)and linear model(LM)*** of the CI was obtained by hyperspectral imaging system in the band between 871 and 1766 *** results showed that average reflectance increases with the rise of N concentration.A substantial portion of the leaf from the plant with 100%N dosage had the darkest image and resulted in the highest reflectance because the N weakened the negative effect of freezing *** of the five spectral domains tested,the best predictive accuracy for the CI of the tea leaf was achieved by PCR(R^(2)=0.9971,RMSE=0.0609)in 1410–1766 nm wavelength,followed by LM(R^(2)=0.9999,RMSE=0.0805)in 871–1000 *** whole interval had the worse prediction accuracy which could be caused by large variations in the data for a specific treatment and high absorption peak occurring around 1450 nm in the reflectance *** averages,R^(2) and RMSE for all the three statistical models showed that the worse prediction accuracy occurred in 1410–1766 nm,followed by the whole interval 871–1766 *** prediction accuracy was low which could be due to the strong water absorption peaks that appeared in both range of *** models without absorption bands had improved correlation coefficient and reduced RMSE values between the measured and the predicted CI(R^(2)=0.9676;RMSE=0.3067)compared to the model developed with the reflectance values in the entire waveband(R^(2)=0.9504;RMSE=0.6629).The reflectance values where absorption bands occurred had detrimental effect on the model performance,which

关键词： Cold injury Hyperspectral imaging Reflectance principal component

基于奇异谱分析的南方涛动指数短期气候预测试验(英文)

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Advances in Atmospheric Sciences 2001年第5期18卷 873-881页

作者：刘健文董佩明 Beijing Aviation Institute of Meteorology Beijing China

The Southern Oscillation Index (SOI) time series is analyzed by means of the singular spectrum analysis (SSA) method with 60-month window length. Two major oscillatory pairs are found in the series whose periods are quasi-four and quasi-two years respectively. The auto-regressive model, which is developed on the basis of the Maximum Entropy Spectrum Analysis, is fitted to each of the 9 leading components including the oscillatory pairs. The prediction of SOI with the 36-month lead is obtained from the reconstruction of these extrapolated series. Correlation coefficient between predicted series and 5 months running mean of observed series is up to 0.8. The model can successfully predict the peak and duration of the strong ENSO event from 1997 to 1998. It's also shown that the proper choice of reconstructed components is the key to improve the model prediction.

关键词： Southern Oscillation Index singular spectrum analysis principal component reconstruction

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关于纤维化奇异纤维的一些新的组合条件

Northeastern Mathematical Journal 1994年第4期10卷 503-510页

作者：唐明元

For any relative minimal fibration of gender g, we have known some basic combinatorialproperties, i. e, the necessary conditions (1)-(5) in this paper. Xiao[1] showed that these conditionsare not sufficient for g>2 and gave another two nccry conditions. In this peper, we use themethed of the Stable Reduction and the roemann-Hurtvitz formula to obtain some new combinatorialconditions. These resultS are reduced to three propeitions.

关键词： Fibration Singular Fibre Base Extension principal component