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In many cases,monitoring data for ambient airborne particles can be organized in the form of a three-way data table with one way for chemical species,one for sampling periods and one for sites.A directtrilinear decomposition followed by a matrix reconstruction(DTDMR)is developed to analyze such adata table as a whole.The three-way data set is composed into three two-way matrices by a direct trilineardecomposition(DTD).The column vectors of each of the matrices are called‘source profiles’,‘emissionpatterns’and‘site coefficients’respectively.Particulate sources are identified by examining both theirsource profiles and emission patterns.After the sources have been identified,emission patterns and sitecoefficients are used to produce a three-way matrix that gives estimates of mass contributions of sourcesto the samples collected at every site in every period.By simulation study,not only has the method beenverified,but a good indicator has been found that shows the number of factors(i.e.sources)in thesystem.Unlike other receptor models,DTDMR does not require source profile data and does not involvetrial-and-error procedures.Since DTDMR identifies sources based on variations in two dimensions,it hasa higher potential to distinguish two sources that have similar chemical compositions.The DTDMRmodel has provided excellent results with simulated data and has been applied in a real world three-waydata set.  相似文献   

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Language plays a vital role in the communication, sharing and transmission of information among human beings. Geographical languages are essential for understanding, investigating, representing and propagating geo-spatial information. Geographical languages have developed and evolved gradually with improvements in science, technology and cognitive levels. Concerning the theoretical progress from geographical information ontology, epistemology and linguistic theory, this paper firstly puts forward the concept of a GIS language and discusses its basic characteristics according to changes in the structures, functions and characteristics of geographical languages. This GIS language can be regarded as a system of synthetic digital symbols. It is a comprehensive representation of geographical objects, phenomena and their spatial distributions and dynamic processes. This representation helps us generate a universal perception of geographical space using geographical scenarios or symbols with geometry, statuses, processes, spatio-temporal relationships, semantics and attributes. Furthermore, this paper states that the GIS language represents a new generation of geographical language due to its intrinsic characteristics, structures, functions and systematic content. Based on the aforementioned theoretical foundation, this paper illustrates the pivotal status and contributions of the GIS language from the perspective of geographical researchers. The language of GIS is a new geographical language designed for the current era, with features including spatio-temporal multi-dimension representation, interactive visualization, virtual geographical scenarios, multi-sensor perception and expedient broadcasting via the web. The GIS language is the highest-level geographical language developed to date, integrating semantic definitions, feature extraction, geographical dynamic representation and spatio-temporal factors and unifying the computation of geographical phenomena and objects. The GIS language possesses five important characteristics: abstraction, systematicness, strictness, precision and hierarchy. In summary, the GIS language provides a new means for people to recognize, understand and simulate entire geo-environments. Therefore, exploration of the GIS language’s functions in contemporary geographical developments is becoming increasingly important. Similarly, construction of the conceptual model and scientific systems of the GIS language will promote the development of the disciplines of geography and geographical information sciences. Therefore, this paper investigates the prospects of the GIS language from the perspectives of digital technology, geographical norms, geographical modeling and the disciplinary development of geography.  相似文献   

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《The Journal of geography》2012,111(6):241-249
Abstract

This article reports the results of an exploratory project to determine the abilities of Grade 6 children to work with digital data. The research questions dealt with understanding what is digital data, understanding what is a pixel, and how digital data can be used, making a digital map, and using pixels to determine area on maps. The results of the project showed that the children in this study were able to work with digital data, and that there is potential for using digital data on the Grade 6 level in geography instruction.  相似文献   

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A ROBUST PLS PROCEDURE   总被引:1,自引:0,他引:1  
A robust partial least squares(PLS)regression algorithm is developed.This is achieved by substitutionof the univariate regression steps in the iterative PLS2 algorithm by a robust alternative.The anglebetween loading vectors from both perturbed and unperturbed solutions is used as a measure ofrobustness.By means of a perturbation study on a structure-activity data set,it is demonstrated thatthe stability of the robust method is superior to standard PLS.  相似文献   

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MARS:A TUTORIAL     
This tutorial paper presents a simplified view of one of the more recently published multivariatecalibration methods particularly suited to dealing with non-linear data sets.The method is referred toas MARS and stands for multivariate adaptive regression splines.Simple examples are provided toexplain the workings of the method.  相似文献   

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Books Reviewed:

Browning, Frank A Queer Geography: Journeys Toward a Sexual Self

Fellows, Will Farm Boys: Lives of Gay Men from the Rural Midwest

Rubenstein, James M. The Cultural Landscape: An Introduction to Human Geography. 6th ed

Knox, Paul L. and Marston, Sallie A. Human Geography: Places and Regions in Global Context

Kuby, Michael; Harner, John, and Gover, Patricia Human Geography in Action  相似文献   

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Entering overseas markets provides challenges for firms, especially for those with little international experience. These obstacles can be compounded for manufacturers of advanced machinery, as previous research suggests that a physical presence is necessary for the successful implementation of their products in export markets. One way for producers to address this issue is to participate in trade fairs, which enables a physical presence of staff and machinery to be established. Evidence from a survey of Korean machinery producers at a recent trade fair suggests that a physical presence is related to the importance that firms ascribe to exports and to the role of trade fairs in new sales.  相似文献   

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A non-parametric method for supervised pattern recognition is presented. The method is of the classmodelling type, meaning that a classification rule is developed for each class, using the dissimilaritiesbetween the objects of the class. The dissimilarities between the objects within a class are related to thedistances between all pairs of training objects. As distance metric, a measure is proposed that takes thecorrelation between the interval-scale variables into account, and that moreover can be used for mixedtypes of variables. The classification rule is based on the construction of a boundary in the measurementspace. For the determination of the class boundary, several strategies are proposed and compared. The performance of the technique is evaluated on the basis of several data sets. Comparison with theclass modelling technique UNEQ shows its usefulness for practical applications.  相似文献   

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A型花岗岩自提出30多年以来,由于其特殊的地球化学特征和独特的构造环境解释一直受到地质学家的关注,其内涵和外延相对于原始定义已经发生了很大的变化。本文主要针对A型花岗岩的概念、判别、分类,以及其成因模式、构造背景和动力学意义等方面对A型花岗岩进行了较为详细的介绍。  相似文献   

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This paper examines the ways that community policing organizes urban space in order to increase the police's ability to observe and to enforce. The logic of that organization, I argue, rests in the particular way that police are integrating civilians into police practice as part of community policing's police-community partnership, a partnership that is characterized by the concrete metaphor of a policing body. This paper presents the results of twenty months of field research with the Boston Police Department whose community policing program, Neighborhood Policing, is being hailed as a national model.  相似文献   

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This paper summarizes the characteristics of 19 scanners costing less than Dfl20000 (US$10000). It also describes the completeness of scanning performed by three of these low-cost scanners (from Agfa, Cannon and Houston Instruments) and the accuracy of one (SCAN-CAD of Houston Instruments). It was found that complete scanning occurs with resolutions of half the minimum map line width and that maximum errors of 0-5 mm were achieved.  相似文献   

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The measurement of agricultural intensity is fundamental to an understanding of spatial organization of agriculture. This paper develops a new index of cropping intensity from land use data. The length of time for which a crop stays in the field, a factor ignored in other indirect measures of cropping intensity, has been incorporated in the new index. To illustrate the method, cropping intensity in India is measured, mapped and discussed. Differences between the patterns derived from the new index and the traditional index are noted and explained.  相似文献   

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池州市A级旅游景区空间结构   总被引:17,自引:2,他引:15  
采用最近邻距离模式、连接度、通达度、紧密度分析的研究方法,从总体空间分布特征与区域内空间分布结构2方面对池州市旅游景区空间结构进行分析测定,发现池州市A级旅游景区空间距离较小,呈集聚型分布;β指数为1.56、γ指数为0.53、平均径路长为3.26,旅游景区间交通网络的通达度较低,交通网络联系程度较弱,尚未形成稠密的旅游交通网络,旅游资源整合水平较低;紧密度指数C为0.55,紧凑程度处于中等,为区内旅游交通建设,提高区内旅游资源网络连通性、通达性提供了较好的基础。  相似文献   

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The Association of American Geographers organized under Engeln, a symposium on the general subject of Penck's contribution to geomorphology and its relation to the .Davisian system. The published Annual of Dec. 1940 devoted .wholly to this subject reached me through Prof. Cressey four years later. It seems to me, being a  相似文献   

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