SHORT COMMUNICATION STRUCTURE MODELLING AND DISCRIMINATION OF CATALAN WHITE WINES     

M.S.LARRECHI  M.R.FRANQUES  M.FERRE  F.X.RIUS 《地理学报(英文版)》1988,(Z1)

Cluster analysis has been applied to characterize the group structures of four sets of Catalan white wines(Conca de Barberà),Camp de Tarragona,Terra Alta and Ribera-Falset)on the basis of eleven classicaloenological parameters and seven micro and trace metallic constituents considered to be relativelyinsensitive to cultural practices.In spite of the vintage variation and the lack of a clear varietaldifferentiation among the wines,each region could be individually characterized.The application ofsupervised pattern recognition methods has allowed regional assignment of unknown samples with aprediction rate higher than 95%.Several metal ions(such as calcium,strontium, zinc and magnesium)and a few classical parameters(such as ethanol content and the sum of malic and lactic acid contents)have been found to be relevant for a correct classification.ALLOC and KNN classification methodscombined with LDA have been proven useful with the present data set,although their performance wasnot superior to that of LDA and SIMCA.  相似文献   

ASSIGNING THE ORIGIN OF CATALAN MEDIEVAL STAINED GLASSES BY PATTERN RECOGNITION METHODS OF X-RAY FLUORESCENCE DATA     

G.RAURET  E.CASASSAS  M.BAUCELLS  M.S.LARRECHI  F.X.RIUS 《地理学报(英文版)》1988,(Z1)

Thirteen different components of six samples belonging to stained medieval glass windows and twelvesimilar samples found in the archives of Girona Cathedral(Catalonia,Spain)during restoration workwere determined by x-ray fluorescence analysis.The use of display and cluster analysis methods,principal components analysis,non-linear mapping,minimal spanning tree and agglomerativehierarchical clustering applied to these results,together with those of nine samples from the samecathedral previously studied,showed the presence of a quite compact cluster formed by the soda-typesamples,indicating a probably similar origin and confirming the peculiarities of this Mediterranean area.The potash-type glasses were highly scattered with little similarity among them,suggesting a likelydifferent source of these samples.The twelve glasses of strictly unknown origin were found to have a highdegree of resemblance to the samples of known context,thus excluding the possibility of them beingsamples made in a very different age or site.Three of them were classified into the same group as thewell-defined soda-type glasses by the pattern recognition method SIMCA.  相似文献   

THE EFFECT OF MISLABELED SAMPLES ON THE PERFORMANCE OF THE LINEAR LEARNING MACHINE     

BARRY K.LAVINE ANTHONY J.I.WARD JIAN HWA HAN Department of Chemistry  Clarkson University  Potsdam  NY  U.S.A.ROY-KEITH SMITH Georgia Department of Agriculture  Capitol Square  Atlant  GA  U.S.A.ORLEY R.TAYLOR Department of Entomology  University of Kansas  Lawrence  KS  U.S.A. 《地理学报(英文版)》1990,(1)

Over the past 15 years the linear learning machine has been applied to a large number of chemicalproblems.The learning machine approach is conceptually simple and does not require knowledge aboutthe statistical distribution of the data.However,there are problems associated with this approach.Oneproblem which has not been investigated is the influence of mislabeled samples on the positioning of thehyerplane in feature space.If a few samples in a data set are incorrectly tagged prior to training(i.e.thesamples are labeled as members of class 2 even though they are actually members of class 1),it is stilIpossible using the linear learning machine to achieve a classification success rate of 100% for the trainingset.However,unfavorable results will be obtained for the prediction set.The magnitude of this effect andits potential implications regarding the proper use of the linear learning machine are discussed.  相似文献   

辽南不同岩性地区地下水动态研究   总被引：2，自引：1，他引：1  

刘庆书  许劲松 《地理研究》1991,10(3):23-29

本文从影响辽南地区地下水动态因素,主要从岩性、蓄水构造的制约因素,探讨分析了辽南不同岩性地带的地下水动态特点,划分了基本类型,揭示其规律性。为因地因时制宜地充分开发,合理有效利用珍贵的地下水资源提供科学依据。  相似文献   

国家湿地公园河流廊道建设模式与技术研究——以江西修河国家湿地公园为例   总被引：1，自引：1，他引：0  

吴后建  但新球  黄琰  刘扬晶  郭克疾 《湿地科学与管理》2009,5(1)

在回顾和总结国内外生态廊道、河流廊道研究进展的基础上,以江西修河国家湿地公园为例,在分析江西修河国家湿地公园的主体——修河河流廊道的现状、建设要求和生态功能侧重点的基础上,确定了修河河流廊道的宽度,提出了针对不同功能需要和不同区段的修河河流廊道建设模式,以期为修河河流廊道的建设提供指导和依据,把修河打造成"蓝水绿岸"式的生态河流廊道,并为我国河流廊道型国家湿地公园的建设模式和技术提供指导。  相似文献   

Spectrothermography of carbonaceous particles     

Oscar Peralta  Darrel Baumgardner  Graciela B. Raga 《Journal of Atmospheric Chemistry》2007,57(2):153-169

Spectrothermography, defined as the evaluation of thermograms of carbon evolved from heated aerosol samples, is a technique for evaluating differences in particle characteristics as they relate to emission sources and processes that modify particle evolution. Here we describe the inherent uncertainties and demonstrate the utility of this technique with an evaluation of samples that were collected with eight stage cascade impactors at three sites in Mexico City over a period of 5 months. The study was implemented with statistical analysis based on tests for goodness of fit to separate thermograms with distinctive shapes related to the relative amounts of organic and elemental carbon mass that evolves as a function of temperature. Thermograms with unique shapes were found for particles with aerodynamic diameters of 1–10, 0.56–1, 0.32–0.56 and 0.18–0.32 μm with further differentiation of curves related to the relative amounts of gasoline and diesel fuel that was combusted in the region of the three sites. The common shapes fit 32–42% of samples in each particle size range and indicate that this type of analysis can help distinguish differences in the primary sources of organic and elemental carbon.

Darrel BaumgardnerEmail:

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秋季热带中太平洋SST异常型与冬季中国降水和气温的关系   总被引：3，自引：1，他引：2  

王苏瑶  李忠贤  王大钧  刘长征 《气象科学》2012,32(6):653-658

用NOAA延长重构的月平均海表温度以及NCEP/NCAR提供的比湿、风场、温度场资料和中国160站的月平均气温、降水资料,利用相关分析及合成分析的方法,研究了秋季热带中太平洋SST异常型的变化特征及其与冬季中国降水和气温的关系。结果表明:(1)秋季热带中太平洋SST异常型具有准10 a周期。(2)当秋季热带中太平洋SST为正异常时,12月份东亚大槽加深,贝加尔湖及其西侧的高压脊加强,有利于来自高纬度的冷空气向中国北方及东部地区输送,850 hPa水汽在江苏及安徽北部、山东南部、河南中部等地存在辐合,使得上述地区降水偏多,反之亦然。(3)当秋季热带中太平洋发生SST正异常时,12月份吉林、辽宁、内蒙古东部及河北气温升高,反之亦然。  相似文献   

A new perspective in identifying the precursory patterns of eruptions   总被引：2，自引：2，他引：0  

Laura?SandriEmail author  Warner?Marzocchi  Lucia?Zaccarelli 《Bulletin of Volcanology》2004,66(3):263-275

The complexity of the processes responsible for volcanic eruptions makes a theoretical approach to forecasting the evolution of volcanic unrest rather difficult. A feasible strategy for this purpose appears to be the identification of possible repetitive schemes (patterns) in the pre-eruptive unrest of volcanoes. Nevertheless, the limited availability and the heterogeneity of pre-eruptive data, and the objective difficulty in quantitatively recognizing complex pre-eruptive patterns, make this task very difficult. In this work we address this issue by using a pattern recognition approach applied to the seismicity recorded during 217 volcanic episodes of unrest around the world. In particular, we use two non-parametric algorithms that have proven to give satisfactory results in dealing with a small amount of data, even if not normally distributed and/or characterized by discrete or categorical values. The results show evidence of a longer period of instability in the unrest preceding an eruption, compared to isolated unrest. This might indicate, even if not necessarily, a difference in the energy of processes responsible for the two types of unrest. However, if the unrest is followed by an eruption, it seems that the seismic energy released during the unrest (parameterized by the duration of the swarm and the maximum magnitude recorded) is not indicative of the magnitude of the impending eruption. We also found that, in general, unrest followed by the largest explosive eruptions have a longer repose time than those related to moderate eruptions. This evidence supports the fact that the occurrence of a large eruption needs a sufficient amount of time after the last event in order to re-charge the feeding system and to achieve a closed-conduit regime so that a sufficiently large amount of gas can be accumulated.Editorial responsibility: T. Druitt  相似文献   

Modification of the pattern informatics method for forecasting large earthquake events using complex eigenfactors   总被引：4，自引：0，他引：4  

J.R. Holliday  J.B. Rundle  K.F. Tiampo  W. Klein  A. Donnellan   《Tectonophysics》2006,413(1-2):87

Recent studies have shown that real-valued principal component analysis can be applied to earthquake fault systems for forecasting and prediction. In addition, theoretical analysis indicates that earthquake stresses may obey a wave-like equation, having solutions with inverse frequencies for a given fault similar to those that characterize the time intervals between the largest events on the fault. It is therefore desirable to apply complex principal component analysis to develop earthquake forecast algorithms. In this paper we modify the Pattern Informatics method of earthquake forecasting to take advantage of the wave-like properties of seismic stresses and utilize the Hilbert transform to create complex eigenvectors out of measured time series. We show that Pattern Informatics analyses using complex eigenvectors create short-term forecast hot-spot maps that differ from hot-spot maps created using only real-valued data and suggest methods of analyzing the differences and calculating the information gain.  相似文献   

A closer look at regime shifts based on coastal observations along the eastern boundary of the North Pacific     

Laurence C. Breaker 《Continental Shelf Research》2007

At least six regime shifts have been reported in the North Pacific since 1920. They occurred in 1925, 1939, 1946, 1976–1977, 1989 and 1999. The major change in 1976–1977 corresponds to a regime shift that is now widely accepted as a canonical event since it had a significant impact on virtually all climatic and ecosystem indicators. We seek to determine if daily sea surface temperature (SST) from Pacific Grove, in central California, and Scripps Pier, in southern California, and coastal observations from several other locations along the west coast of North America can be used to detect and resolve these events. Cumulative sums (CUSUMs) were initially calculated to enhance the detection process. The CUSUM trajectories during the 1976–1977 event at Pacific Grove and Scripps Pier were distinctive, highly correlated, and in phase. The turning point patterns from this event were then used to search for other events that have been reported since 1920. Turning point patterns very similar to the 1976–1977 event were detected in 1946 and 1989. The events in 1925 and 1939 were generally similar, but the CUSUM patterns for the event in 1999 departed significantly from the other events. Further examination of the 1976 and 1989 events revealed inflection points in the CUSUMs near the beginning and end of each transition that correspond to critical values or extrema in the original data. The inflection points and/or critical values provide an improved basis for determining the duration of these events.  相似文献