A statisticalmethod for the detection of geographic clustering
Methodology ; Probability ; Spatial analysis ; Spatial autocorrelation ; Statistics ; Test
The A. suggests an approach for assessing the significance of peaks in the surface that result from the application of the smoothing kernel. The approach may also be thought of as a method for assessing the maximum among a set of suitably defined
local statistics. Local statistics for data on a regular grid of cells are first defined by using a Gaussian kernel. Results from integral geometry are used to find the probability that the maximum local statistic exceeds a given critical value.
Analyse multivariée ; Généralités sur la géographie ; Méthode statistique ; Régionalisation ; Statistique
An attempt has been made to review the available important statisticalmethods of regionalisation through by grouping disaggregated data into some homogeneous groups such that the inter group heterogeneity and within the group homogeneity
A distribution-free statisticalmethod for the spatial characterization of dune granulometry : an example from the Strzelecki Desert, South Australia
Aeolian features ; Australia ; Barchan ; Desert ; Dune ; Grain size distribution ; Sedimentology ; South Australia ; Statistical distribution ; Statistics
This technical communication discusses the manner in which spatial granulometric differences for barchan dunes can be confidently and accurately identified using non-parametric statisticalmethods.
To offer a more formal approach in line with classical statistical framework, the AA. develop an exact method for computing the p-values of the local Moran's Ii, local Geary's ci, and the modified Ord and Getis G statistics based
on the distributional theory of quadratic forms in normal variables. Furthermore, an approximate method is also proposed to achieve a computational cost lower than the exact method. The study not only provides an exact test for local patterns of spatial association
, but also puts the tests of several local statistics within a unified statistical framework.
Hypoteseproving for geografer. Elementaert statistisk grunnlag og testmetoder. Kvantitative metoder Cg18 Testing of hypothesis for geographers. Basic statistics and test methods. Quantitative methods Cg18
An evaluation of environmental protection agency-sanctioned statisticalmethods used in the assessment of groundwater quality
Eau souterraine ; Evaluation ; Méthode de contrôle ; Protection de la nature ; Qualité de l'eau ; Ressource naturelle ; Statistique
Ground water ; Natural resources ; Nature conservation ; Statistics ; Water quality
influenced by the statisticalmethod used.
Various groundwater conditions are simulated and the ability of the methods to detect significant changes in contamination levels is compared. The results show that the determination of whether the groundwater has been contaminated may be unduly
Statistical downscaling estimates of high temperature in summer in Japan
Climatic warming ; Forecast ; Global change ; Honshu ; Japan ; Model ; Regional climate ; Regression analysis ; Statistics ; Summer ; Temperature
In this study, a statistical downscaling method was applied to estimate August mean daily maximum temperature in Japan so that the applicability of the method to extreme temperature in the region was examined. The model related the local variable
with the principal components of large-scale climate variables over the region using stepwise multiple regression analysis. The statistical model was evaluated by the cross validation procedure. It was confirmed that the method is applicable to the estimation of high
The K-function method on a network and its computational implementation
Distance ; Distribution of points ; Methodology ; Network ; Spatial statistics ; Statistics
L'A. présente deux méthodes statistiques (network K-function method et network cross K-function method) pour analyser la distribution de points dans un réseau. Exemple de la distribution de commerces le long d'un réseau de rues.
SMT : a spatial mapping tool for statistical data set
Using the GIS techniques, and supported by Auto CAD software, the A. develops a practical method to make statistical maps and a software (SMT) to make small-scale statistical maps using C language.
Evaluation du paysage ; Généralités sur la géographie ; Méthode statistique ; Paysage ; Pratique de la géographie
En général les géographes sont réticents devant les méthodes statistiques d'évaluation de la qualité esthétique d'un paysage. L'A. recherche les raisons de ce rejet.
Possibilités d'application de nouvelles méthodes mathématiques dans les recherches microclimatiques
Climatology ; Methodology ; Microclimate ; Research ; Statistics
of this function can be examined in the original points of reference by statisticalmethods. - (JS)
Author introduces a new method which can be used for microclimatic research. The essence of the method is: data series are transformed to function by Lagrange interpolation or spline interpolation. Then the derivate is calculated and the values
The statistical analysis through a computational method of a distribution of points in relation to its surrounding network
Méthode statistique pour tester si une distribution de points sur un plan est indépendante d'un élément de type-réseau. Méthode pour informatiser ce test.
Matematikai modszerek felhasznalhatosaga a mezogazdasagi területi elemzésekben. (Applicability of mathematical methods in regional agricultural analyses)
The authors evaluate the efficiency of non-formal methods (factorial analysis as a statistical and as a classification method, Berry's, Farrell's methods, the ORLINE and the gravity methods). The conclusions drawn from the use of their 14-criterion
The rank adjacency statistic D provides a simple method to assess regional clustering. The usual normal approximation is found to give inaccurate results if the data are sparse and some regions have tied ranks. Ajusted formulae for the moments of D
that allow for the existence of ties are derived. It is a valid approximate method to evaluate spatial clustering, even in sparse data situations (for mortality).
Mesure statistique des associations spatiales dans un certain nombre de circonstances. Propriétés et avantages de la méthode, appliquée à une variable donnée selon la distance à un point particulier. Comparaison avec la méthode de Moran
Quatre méthodes statistiques pour examiner la distribution des points sur un réseau (comme les magasins le long des rues). Méthode de la distance (plus proche voisin) avec extension du plan au réseau. Mesure de l'influence respective des types de