共查询到20条相似文献，搜索用时 31 毫秒
1.
MASSIMOBARONI SERGIOCLEMENTI GABRIELECRUCIANI GABRIELECOSTANTINO DANIELARIGANELLI ERMANNO OBERRAUCH 《地理学报(英文版)》1992,(6)
A procedure called GOLPE is suggested in order to detect those variables which increase the predictivityof PLS models.The procedure is based on evaluating the predictive power of a number of PLS modelsbuilt by different combinations of variables selected according to a factorial design strategy.Examplesare given of the efficiency of this variable selection procedure,which shows how these predictive PLSmodels are better than those obtained by all variables and better than the corresponding ordinaryregression models. 相似文献
2.
Charles C. Ryerson 《The Professional geographer》1984,36(3):345-352
Access to the sun for space heating of structures is controlled, in part, by topographic shadowing in high-relief regions. A simple graphic procedure is presented for mapping shadows on topographic maps for any date and time of day. Comparisons of computed shadows and shadows measured from aerial photography confirm that the mapping procedure is reliable and accurate. Use of the procedure as a solar access inventory tool is illustrated in an area of the Green Mountains, VT. 相似文献
3.
In this study, we present a fully automated procedure to analyze online news using data mining techniques. It is then used to compile and continually update a geohazard database. The procedure is based on new technologies that publish news on the internet, i.e., the news is analyzed, georeferenced and attributed to a category of geohazards (the current categories are landslides, floods and earthquakes). A continuous flow of georeferenced events is established to populate and update the geodatabase automatically and in near-real time. We tested the procedure for 2 years at a national scale, creating a geodatabase containing more than 20,000 news items concerning geohazards that occurred in Italy. This procedure enables continuous feedback from events in the real world, such that information about geohazards can be fully exploited rapidly (compared to traditional techniques based on remote sensing, field surveys and historical inventories). 相似文献
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5.
A procedure for determining the transition time in chronopotentiometry is proposed.The method isbased on the existence of three straight sections in a chronopotentiometric curve.The experimentalvalues are fitted by multilinear regression using dummy variables.Agreement between the proposedmethod and a classical graphical procedure is observed. 相似文献
6.
Least-squares fitting of marine seismic refraction data 总被引：2，自引：0，他引：2
Summary. An iterative procedure is presented for fitting waveform data from a marine seismic refraction experiment. The wavefunction from the explosive source is known and the crustal structure is refined using the damped least squares procedure. The damping parameter serves the dual purpose of stabilizing an under-constrained inversion and improving the linearity by suppressing high frequencies. The synthetic seismograms and their model differentials are calculated using the WKBJ seismogram method. Both the synthetic seismograms and the linear algebra are sufficiently straightforward that the computations can be performed on an array processor. The inversion procedure is then sufficiently rapid that interactive computations are possible. The technique is illustrated using the FF2 refraction data from the Fanfare cruise of the Scripps Institution of Oceanography. These data had been interpreted previously by trial-and-error using the reflectivity method. Starting from two different, simple models, the inversion procedure obtains essentially one unique model. Its features are very similar to the previous model. 相似文献
7.
In a recent paper, Wong outlined the benefits of the IPF procedure, which he claimed had received little attention from geographers. This follow-up paper introduces a large literature, ignored by Wong, which uses that procedure, but within the context of another mathematical model. Its application is illustrated with new analyses of recent voting patterns in Great Britain. 相似文献
8.
Among the several measures being adopted to upgrade the level of education in Israel is the policy of maintaining an equal achievement level in all public high schools. Short-run allocation of elementary school graduates to schools is therefore needed. This paper presents a spatial allocation procedure which aims at improving achievement equality simultaneously with upgrading accessibility to schools. The procedure allows the mutual effect of these two factors to be varied, as well as the measurement of the real-world meaning of such variations. The advantages of the proposed procedure in comparison with the common linear programming model used in spatial planning of school districts are discussed. Allocation patterns generated for the city of Beer Sheva illustrate its use. 相似文献
9.
Michele Crosetto Stefano Tarantola 《International journal of geographical information science》2013,27(5):415-437
A novel procedure to analyse the uncertainty associated to the output of GIS-based models is presented. The procedure can handle models of any degree of complexity that accept any kind of input data. Two important aspects of spatial modelling are addressed: the propagation of uncertainty from model inputs and model parameters up to the model output (uncertainty analysis); and the assessment of the relative importance of the sources of uncertainty in the output uncertainty (sensitivity analysis). Two main applications are proposed. The procedure allows implementation of a GIS-based model whose output can reliably support the decision process with an optimized allocation of resources for spatial data acquisition. This is possible in low cost strategy, based on numerical simulations on a small prototype of the GIS-based model. Furthermore, the procedure provides an effective model building tool to choose, from a group of alternative models, the best one in terms of cost-benefit analysis. A comprehensive case study is described. It concerns the implementation of a new GIS-based hydrologic model, whose goal is providing near real-time flood forecasting. 相似文献
10.
The paper presents a procedure to obtain response surfaces with non-designed data.The method is basedon PLS modelling of the expanded X-matrix followed by transformation of the PLS loadings intopolynomial coefficients and detection of the co-ordinates of the best response within the experimentaldomain.The results are presented both graphically and numerically.The procedure is validated on anoptimization study of the yield of an organic reaction. 相似文献
11.
Regularized discriminant analysis has proven to be a most effective classifier for problems wheretraditional classifiers fail because of a lack of sufficient training samples,as is often the case in high-dimensional settings.However,it has been shown that the model selection procedure of regularizeddiscriminant analysis,determining the degree of regularization,has some deficiencies associated with it.We propose a modified model selection procedure based on a new appreciation function.By means ofan extensive simulation it was shown that the new model selection procedure performs better than theoriginal one.We also propose that one of the control parameters of regularized discriminant analysis beallowed to take on negative values.This extension leads to an improved performance in certain situations.The results are confirmed using two chemical data sets. 相似文献
12.
Gorm Dybkjær Thomas Theis Nielsen Kjeld Rasmussen Michael Schultz Rasmussen Lars Boye Hansen Assize Touré 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):125-135
A NOAA AVHRR data set covering Senegal and parts of the surrounding countries during the period from 1987 to present is under construction and improvement in an ongoing collaboration between Centre de Suivi Écologique (CSE). Dakar. Senegal, and Institute of Geography, University of Copenhagen (IGUC). This paper details the entire processing chain from raw images to a properly calibrated, geometrically rectified and cloud-masked time-series tracking a number of well-defined variables. Two vital aspects of this time series, the cloud masking procedure and the geometrical rectification, are evaluated in detail. A two-step, multi-criteria cloud masking procedure requiring a manual input does not consistently improve the quality of the data set compared to the simpler, automated procedure. With respect to geometrical rectification an accuracy on the order of I km is obtained. Finally, suggestions for further improving the data set are forwarded 相似文献
13.
This paper presents a multi-level procedure for production and injection scheduling through a numerical model-based optimization of well control variables. To calculate the net present value (NPV), the objective function of optimization, this procedure uses a number of discretized systems for a reservoir model with different degrees of up-scaling prepared according to a multi-resolution wavelet technique. These up-scaled models were incorporated into optimization based on a probability function. In early optimization iterations, due to the necessity to explore the search space quickly, the coarsest grid model has a higher chance for selection than the others; however, by a selection (with a low probability) of the finest up-scaled grid model in these iterations, solutions and objective function were tuned. In the later iterations of optimization, the finest up-scaled grid model probability was the highest in order to ensure the reliability of the final solution. The optimization algorithm is an adaptive simulated annealing algorithm coupled with a polytope. This procedure was evaluated in two case studies. The first case study was a horizontal 2D oil model with water flooding. The second case study was a vertical 2D oil model with gas injection. The results show that the proposed optimization procedure provides approximately the same accuracy compared to the situation in which the fine grid model is used for all the optimization iterations. Also, the run-time for the proposed optimization procedure is comparable to the run-time of the optimization in which only the coarsest grid model is used to calculate objective function. Moreover, the superiority of the wavelet-based up-scaling over an analogous multiple grid system optimization using uniformly up-scaled models is presented.
相似文献14.
R. J. Fryer 《Geophysical Journal International》1975,42(3):893-898
Summary. The need for, and difficulties commonly experienced during, the analysis of patterns of vectors with superimposed 'noise' upon the surfaces of spheres is discussed. A simple procedure is described whereby many of these difficulties may be circumvented and certain classes of systematic array detected even against a considerable random background. An extension of the same procedure to the analysis of vector patterns in a plane is discussed. 相似文献
15.
M. J. Pasqualetti 《The Professional geographer》1986,38(1):82-87
Low temperature geothermal energy requires that precedence for development be given land use characteristics in communities of proposed utilization. A procedure which uses Scottsdale, Arizona as the model involves overlaying maps of user energy density, parcel ownership, parcel size, parcel vacancy, and zoning. An analysis of existing geochemical and geological data and cost/benefit followed and allowed further refinement. Adopting this procedure elsewhere would accelerate direct usage of geothermal energy. 相似文献
16.
A major difficulty in remote sensing is handling the many data from sensors aboard aircraft and satellites. In this paper we identify an optimal procedure for sampling remotely sensed data before their storage or on their retrieval. The procedure depends on spatial correlation in the scene and uses kriging to estimate values that have been lost. An example in which data from an airborne multispectral scanner could be diminished to only about one tenth without serious loss of precision illustrates the method. 相似文献
17.
香港回归后内地和香港分别处于两个不同的环境法制区域,环境问题没有边界,通过对两地ＥＩＡ体系的比较,有利于双方互相借鉴,更好地发挥ＥＩＡ的效能,本文从ＥＩＡ的发展历程、制度体系、工作程序及发展趋势等方面对内地和香港ＥＩＡ的体系进行比较研究,指出ＥＩＡ时空范围拓展化、工作程序透明化、跟进工作电子化以及跨境项目协作化将是重要的发展趋势。 相似文献
18.
RICHARD ASPINALL 《International journal of geographical information science》2013,27(2):105-121
Abstract This paper describes an inductive modelling procedure integrated with a geographical information system for analysis of pattern within spatial data. The aim of the modelling procedure is to predict the distribution within one data set by combining a number of other data sets. Data set combination is carried out using Bayes’ theorem. Inputs to the theorem, in the form of conditional probabilities, are derived from an inductive learning process in which attributes of the data set to be modelled are compared with attributes of a variety of predictor data sets. This process is carried out on random subsets of the data to generate error bounds on inputs for analysis of error propagation associated with the use of Bayes’ theorem to combine data sets in the GIS. The statistical significance of model inputs is calculated as part of the inductive learning process. Use of the modelling procedure is illustrated through the analysis of the winter habitat relationships of red deer in Grampian Region, north-east Scotland. The distribution of red deer in Deer Management Group areas in Gordon and in Kincardine and Deeside Districts is used to develop a model which predicts the distribution throughout Grampian Region; this is tested against red deer distribution in Moray District. Habitat data sets used for constructing the model are accumulated frost and altitude, obtained from maps, and land cover, derived from satellite imagery. Errors resulting from the use of Bayes’ theorem to combine data sets within the GIS and introduced in generalizing output from 50 m pixel to 1 km grid squares resolution are analysed and presented in a series of maps. This analysis of error trains is an integral part of the implemented analytical procedure and provides support to the interpretation of the results of modelling. Potential applications of the modelling procedure are discussed. 相似文献
19.
B. A. Hobbs 《Geophysical Journal International》1982,68(1):253-264
Summary. A method is described for finding a resistivity model that fits given magnetotelluric data in the one-dimensional case. The procedure is automatic and objective in that no a priori model structure is imposed. Starting with a uniform half space derived directly from the data, the procedure gradually transforms the half space to one with a continuous and smooth resistivity distribution whose response fits the measured data. The method is illustrated by application to two magnetotelluric data sets. 相似文献
20.
David Serrano Giné Joan Jurado Rota María Yolanda Pérez Albert Carla Bonfill Cerveró 《The Professional geographer》2018,70(3):412-422
The aim of this article is to introduce the Beach Crowding Index (BCI), a procedure to assess the social carrying capacity of vulnerable beaches. The study uses the people at one time (PAOT) approach and data gathered weekly throughout the bathing season regarding the number of beachgoers in 100 m2 cells of the beach to assess how many beachgoers it can comfortably hold. The procedure is based on fieldwork, interviews with beachgoers, and geographic information system (GIS) analysis and has been tested on four beaches in protected areas on the Spanish Mediterranean coast. On a scale from 0 to 4, minimum scores throughout the bathing season are 0.7 and maximum 3.7, although results showed wide variation between the beaches, the section of the beach, and the time of day. This study suggests that determining the location of beachgoers and collecting a long-term series of data is fundamental to assessing social carrying capacity and that the BCI procedure can be used for a large number of applications. 相似文献