共查询到20条相似文献，搜索用时 15 毫秒
1.
《Urban geography》2013,34(6):515-529
The present paper demonstrates that Kelly's (1955) method of hand factor analyzing the data matrices derived from repertory grids can be employed as a general method of multivariate analysis in geography. This brings the advantages of a non-parametric and noncomputer dependent approach to areas such as factorial ecology, classifications of towns and cities, and urban behavioral analyses, where multivariate techniques have customarily been employed. The method is initially explained by recourse to a simple hypothetical urban retailing data set. Subsequently, more complex real world examples involving multivariate analyses of housing data for Barbados, West Indies, and urban consumers' cognitions of a single store are presented. It is shown that the nonparametric method gives results that are virtually identical to those obtained from traditional computer-based factor analyses. Throughout the paper, the pedagogic and practical virtues of the nonparametric method are considered. 相似文献
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V.S.ROSE R.M.HYDE Department of Physical Sciences Wellcome Research Laboratories South Eden Park Ro Beckenham Kent BR BS U.K.H.J.H.MACFIE AFRC Institute of Food Research Reading Laboratory Shinfiel Reading RG AT U.K. 《地理学报(英文版)》1990,(5)
A survey of members of the U.K.QSAR Discussion Group has been made to determine the extent ofuse and development of chemometric and artificial intelligence(AI)methods in the analysis ofmultivariate quantitative structure-activity relationship(QSAR)data in the U.K.Chemometric methodswere found to be well established in both industrial and educational establishments and there wassignificant method development occurring.AI methods were not employed to any great extent and thegeneral level of interest in these techniques was low compared to chemometric methods.A requirementfor more education in multivariate statistical methods and regression methods was indicated.A need fora user-friendly,comprehensive,commercially available multivariate statistical package containingmultivariate stability testing and regression diagnostic methods was identified. 相似文献
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Mathias Trachsel Bjørn Christian Kvisvik Pål Ringkjøb Nielsen Jostein Bakke Atle Nesje 《Journal of Paleolimnology》2013,50(4):583-592
Reflectance spectroscopy in the visible spectrum (VIS-RS) is a method that has been successfully applied for inferring organic content of sediments. In this study, we test the applicability of VIS-RS to lake sediments in Norway. On the one hand we use conventional, established algorithms for inferring organic content of sediments, on the other hand we test the potential of multivariate calibration techniques to infer organic content. For absolute quantification of organic content, conventional Corg measurements are needed when using conventional algorithms as well as when employing multivariate calibration techniques. Both, conventional algorithms and multivariate calibrations, result in estimates of organic content closely mirroring loss-on-ignition measurements. When using multivariate calibration techniques, a conventional Corg measurement every 5 cm is sufficient to obtain estimates of organic matter that are more accurate than those obtained by means of conventional algorithms. Therefore, the potential of multivariate calibration techniques and VIS-RS to substitute measurements of more time consuming and costly sediment parameters (e.g. clay minerals) should be tested. 相似文献
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When the number of variables exceeds the number of samples, one method of multivariate discriminationis to use principal components analysis to reduce the dimensionality and then to perform canonicalvariates analysis (PC-CVA). This paper proposes an alternative approach in which discriminant analysisis carried out by a weighted principal component analysis of the group means (DPCA). This method doesnot require prior data reduction and produces discriminant factors that are orthogonal in the original dataspace. The theory and performance of the two methods are compared. Although the individual factors ofDPCA are found to be less discriminating than PC-CVA, the overall discrimination, calculated bymultivariate analysis of variance, and the predictive value, estimated by the leaving-one-out error rate,are broadly comparable. 相似文献
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基于多元成土因素的土壤有机质空间分布分析 总被引：6，自引：0，他引：6
以陕西省蓝田县2013年667份土壤有机质样本为对象,运用GIS空间分析及遥感数字图像处理收集整理土壤类型、地形、植被等成土因子,利用多元线性回归分析集成所有成土因子对土壤养分进行空间分布预测。结果表明:通过分级统计均值定权法和像元线性拉伸法将所有成土因子统一为相对度量值,并根据成土因子与有机质含量的相关性显著程度进行因子取舍,有利于集成各类成土因子构建多元线性回归模型。预测结果定性分析表明:多元线性回归预测结果与kriging法预测结果在宏观上具有一致的空间分布趋势;但多元线性回归预测结果土壤有机质空间分布特征带有各种成土因子的变化特征,从视觉效果上,克服了传统插值法中存在的斑块状分布现象,更精细的描述了本区域内有机质空间分布趋势; MPE和RMS定量精度分析显示,在集成多元成土因素对有机质进行空间分布分析时,本文方法优于常用kriging插值法,该法可作为集成多元成土因子对土壤养分空间分布预测的有效方法。本区域内土壤有机质高值区域主要集中在地势低平、坡度缓和、湿度适中的农耕区,地势较高、坡度陡的山区有机质含量低。 相似文献
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为研究雅砻江上游径流的变化及其积雪、气温和降水对径流的影响,首先根据相关性将年径流周期分为枯水期、融雪影响期和汛期,其次,结合MODIS 8天积雪产品、研究区气温和降水数据,采用相关分析和归因分析法分析了径流与影响因素的相关性以及各影响因素对径流变化的影响程度,最后用逐步多元回归分析法得出枯水期和融雪影响期径流的预测方程。结果表明：2000-2014年间雅砻江上游径流整体呈上升趋势,冬季积雪面积的减少导致径流减少了24.89%,汛期降水增加导致径流增加了79.38%,采用相关分析和逐步多元回归方法可有效分析径流与影响因素的关系及影响程度。 相似文献
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中国天山山区潜在蒸发量的时空变化 总被引：23，自引：2，他引：21
利用24个气象站1960-2006年的逐日气象资料,应用FAO Penman-Montcith模型,分析了天山山区潜在蒸发量的变化趋势,并在ArcGIS环境下通过IDW插值法分析了潜在蒸发量变化的空间分异,此外运用多元回归分析法对影响潜在蒸发量变化的主导因素进行了探讨.结果表明:年潜在蒸发量自60年代以来呈波状减小趋势,1986年之后减小趋势更加明显,2000年以后呈增加趋势.年潜在蒸发量的年际变化倾向率为-2.48 mm/a,表明潜在蒸发量总体上呈减小趋势;从季节来看,秋季的潜在蒸发量呈增加趋势,其它季节呈减小趋势,其中春季的减小幅度最大;风速是影响潜在蒸发量变化的主导因素,影响秋季潜在蒸发量变化的主导因素是气温. 相似文献
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本文用灰色系统理论的关联分析方法研究影响黄河上游春季融雪径流的各种因素与径流的关联程度,从而为融雪径流模式(简记为SRM)预报因子的合理确定提供依据。这种分析方法与传统的数理统计方法相比,省时省力且准确程度较高,为多变量相关分析提供了一个令人鼓舞的途径。 相似文献
10.
XIN M.TU 《地理学报(英文版)》1991,(4)
Rank estimation by canonical correlation analysis in multivariate statistics has been proposed as analternative approach for estimating the number of components in a multicomponent mixture.Amethodological turning point of this new approach is that it focuses on the difference in structure ratherthan in magnitude in characterizing the difference between the signal and the noise.This structuraldifference is quantified through the analysis of canonical correlation,which is a well-established datareduction technique in multivariate statistics.Unfortunately,there is a price to be paid for having thisstructural difference:at least two replicate data matrices are needed to carry out the analysis.In this paper we continue to explore the potential and to extend the scope of the canonical correlationtechnique.In particular,we propose a bootstrap resampling method which makes it possible to performthe canonical correlation analysis on a single data matrix.Since a robust estimator is introduced to makeinference about the rank,the procedure may be applied to a wide range of data without any restrictionon the noise distribution.Results from real as well as simulated mixture samples indicate that when usedin conjunction with this resampling method,canonical correlation analysis of a single data matrix isequally efficient as of replicate data matrices. 相似文献
11.
ReinaldoPaulPérezMachado ViolêtaSaldanhaKubrusly Ligia Vizeu Barrozo 陈明玉 顾朝林 《地理研究》2016,35(7):1370-1382
空间数据和地理信息系统在城市规划和决策中应用的重要性日见凸显。主要原因在于：重要的人口数据和社会变动经常表现出一定的空间特性,这种特性可以通过空间分析和统计方法被认识和解释。应用多元分析的空间分类方法编制圣保罗大都市区社会分异地图并进行相关分析。研究的主要数据来自2000年巴西全国人口普查,其中包括了圣保罗大都市的所有行政区和39个自治市的21774个人口普查区。为了把都市连绵区从数据全集中分离出来,我们采用混合技术进行互补分析,即在2000年4月30日的陆地卫星7号图像中绘制一个个多边形,这些被识别出来的多边形就是人口普查区。然后,通过目视解译出假彩色多边形集合。应用空间分类评分程序将这些多边形分成五类,并建立人口普查区的数目、覆盖的面积和都市连绵区之间的关系。这种多元分析方法是基于变量的均衡化来生成易于用分级统计图描述平均值,以促进可视化和后续的空间分布分析。基于多元分析的空间分类方法研究,清楚地展现了圣保罗大都市最重要的社会特征,也说明城市社会地图方法和多元分析的空间分类方法在大都市区的管理、公共政策规划和复杂决策中具有重要的应用价值。 相似文献
12.
In geostatistics, most stochastic algorithm for simulation of categorical variables such as facies or rock types require a
conditional probability distribution. The multivariate probability distribution of all the grouped locations including the
unsampled location permits calculation of the conditional probability directly based on its definition. In this article, the
iterative proportion fitting (IPF) algorithm is implemented to infer this multivariate probability. Using the IPF algorithm,
the multivariate probability is obtained by iterative modification to an initial estimated multivariate probability using
lower order bivariate probabilities as constraints. The imposed bivariate marginal probabilities are inferred from profiles
along drill holes or wells. In the IPF process, a sparse matrix is used to calculate the marginal probabilities from the multivariate
probability, which makes the iterative fitting more tractable and practical. This algorithm can be extended to higher order
marginal probability constraints as used in multiple point statistics. The theoretical framework is developed and illustrated
with estimation and simulation example. 相似文献
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Artificial Neural Networks in Proglacial Discharge Simulation: Application and Efficiency Analysis in Comparison to the Multivariate Regression; A Case Study of Waldemar River (Svalbard) 
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下载免费PDF全文 Artificial neural networks were applied to simulate runoff from the glacierized part of the Waldemar River catchment (Svalbard) based on hydrometeorological data collected in the summer seasons of 2010, 2011 and 2012. Continuous discharge monitoring was performed at about 1 km from the glacier snout, in the place where the river leaves the marginal zone. Averaged daily values of discharge and selected meteorological variables in a number of combinations were used to create several models based on the feed‐forward multilayer perceptron architecture. Due to specific conditions of melt water storing and releasing, two groups of models were established: the first is based on meteorological inputs only, while second includes the preceding day's mean discharge. Analysis of the multilayer perceptron simulation performance was done in comparison to the other black‐box model type, a multivariate regression method based on the following efficiency criteria: coefficient of determination (R2) and its adjusted form (adj. R2), weighted coefficient of determination (wR2), Nash–Sutcliffe coefficient of efficiency, mean absolute error, and error analysis. Moreover, the predictors' importance analysis for both multilayer perceptron and multivariate regression models was done. The performed study showed that the nonlinear estimation realized by the multilayer perceptron gives more accurate results than the multivariate regression approach in both groups of models. 相似文献
14.
New expressions are derived for the standard errors in the eigenvalues of a cross-product matrix by themethod of error propagation.Cross-product matrices frequently arise in multivariate data analysis,especially in principal component analysis (PCA).The derived standard errors account for the variabilityin the data as a result of measurement noise and are therefore essentially different from the standarderrors developed in multivariate statistics.Those standard errors were derived in order to account for thefinite number of observations on a fixed number of variables,the so-called sampling error.They can beused for making inferences about the population eigenvalues.Making inferences about the populationeigenvalues is often not the purposes of PCA in physical sciences,This is particularly true if themeasurements are performed on an analytical instrument that produces two-dimensional arrays for onechemical sample:the rows and columns of such a data matrix cannot be identified with observations onvariables at all.However,PCA can still be used as a general data reduction technique,but now the effectof measurement noise on the standard errors in the eigenvalues has to be considered.The consequencesfor significance testing of the eigenvalues as well as the usefulness for error estimates for scores andloadings of PCA,multiple linear regression (MLR) and the generalized rank annihilation method(GRAM) are discussed.The adequacy of the derived expressions is tested by Monte Carlo simulations. 相似文献
15.
主成分分析法在新疆兵团经济可持续发展能力评价中的应用 总被引：1，自引：0，他引：1
采用多元统计主成分分析方法对新疆兵团13个师1991～2006年的各师农场职工家庭人均纯收入、人均农业增加值、人均工业增加值、人均第二产业增加值、人均GDP等11个经济指标进行分析计算并且对各师的综合经济可持续能力进行比较。结果表明：从原始数据中提出占总方差86．6％的4个因子来反映各师的经济可持续发展程度,经分析发现影响各师的4个主成分因子：（1）人均GDP、人均工业增加值（包括第二产业、第三产业的增加值）的因子控制;（2）人均新增固定资产、人均固定资产投资等反映人均资产投入的综合指标;（3）反映人均耕地面积、人均利润、人均社会消费品零售总额的综合指标。（4）反映人均农业增加值、人均固定资产投入及人均社会消费品零售总额的综合指标。然后将各主成分得分结合主成分权重进行计算得出各师经济可持续能力值,其中农一师排在第一。从总体上看1992～2006年各师经济可持续发展的综合指标趋势是逐渐上升的,发展具有可持续性。, 相似文献
16.
The need for a conservation policy for remnant semi-natural vegetation in the agricultural landscape of lowland Britain is stressed. An essential prerequisite for such a policy involves the formulation of a method for habitat assessment which may provide relevant ecological information to planners, land owners and land managers. Existing techniques of ecological evaluation and their problems are briefly reviewed and a new approach, habitat inventory analysis, is described. In addition to measures of habitat and species diversity, variables related to the size and fragmentation of remnant habitats are emphasized and the potential of selected techniques of multivariate analysis for ordering the data is demonstrated. Examples of the use of the method in parts of Cornwall and Dorset are presented and the complete methodology is critically discussed. 相似文献
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对托素湖沉积岩芯采用高分辨率XRF扫描分析法进行地球化学元素测试,运用多元统计分析法中的相关性分析、聚类分析及因子分析判别出不同沉积组分,揭示了托素湖沉积物中Si、Al、K、Ti、Ca、Sr、S、Cl、Br等元素的地球化学特征及其所指示的环境意义。同属强烈迁移型元素Ca、Sr在沉积物中主要受托素湖中内生碳酸盐的影响;而外源碎屑元素Si、Al、K、Ti主要受托素湖流域侵蚀的控制,其变化受托素湖流域降水量的控制,一定程度上指示了流域的干湿波动和极端气候事件发生的幅度与频率。 相似文献
19.
N.BRATCHELL 《地理学报(英文版)》1989,(3)
Analysis of multivariate response data by modelling the principal components of the response has beenapplied to two sets of data. In both cases principal components analysis revealed the relationships amongthe response variables and exploited them to simplify the problem of modelling and optimizing themultivariate response. The models and optima obtained from the principal components comparedfavourably with the individual models and simultaneous optima. 相似文献