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1.
This paper discusses a modeling approach for spatial-temporal prediction of environmental phenomena using classified satellite
images. This research was prompted by the analysis of change and landscape redistribution of petroleum residues formed from
the residue of the burning oil wells in Kuwait (1991). These surface residues have been termed “tarcrete” (El-Baz et al. 1994).
The tarcrete forms a thick layer over sand and desert pavement covering a significant portion of south-central Kuwait. The
purpose of this study is to develop a method that utilizes satellite images from different time steps to examine the rate-of-change
of the oil residue deposits and determine where redistribution is are likely to occur. This problem exhibits general characteristics
of environmental diffusion and dispersion phenomena so a theoretical framework for a general solution is sought. The use of
a lagged-clique, Markov random field framework and entropy measures is deduced to be an effective solution to satisfy the
criteria of determination of time-rate-of-change of the surface deposits and to forecast likely locations of redistribution
of dispersed, aggraded residues. The method minimally requires image classification, the determination of time stationarity
of classes and the measurement of the level of organization of the state-space information derived from the images. Analysis
occurs at levels of both the individual pixels and the system to determine specific states and suites of states in space and
time. Convergence of the observed landscape disorder with respect to an analytical maximum provide information on the total
dispersion of the residual system.
Received: 5 September 2000 / Accepted: 10 July 2001 相似文献
2.
Spatial accessibility is a critical consideration in the provision of services, both public and private. In public transit
planning, accessibility is comprised of access and geographic coverage. Interestingly, these two considerations are somewhat
at odds with each other. Access is important because it is the process associated with getting to and departing from the service.
Such access is typically perceived of in spatial terms as the physical proximity to transit stops or stations. Additional
stops along a route usually mean greater access, because a stop is more likely to be within an acceptable walking/driving
standard for a larger number of people. On the other hand, more stops and greater access slow transit travel speeds, thereby
decreasing the area of service reachable given a travel time budget. More stops along a route translate to greater service
interruption and longer travel times. The faster the travel time, the more desirable the service. Further, if travel times
become excessive, then user demand for service will decrease. All of this means that stop spacing along a route is central
to accessibility, as it is a tradeoff of access (more stops) and geographic coverage (service efficiency through less stops).
This paper details modeling approaches for addressing accessibility concerns in an integrated fashion. Bus-based transit service
in Columbus, Ohio will be utilized to illustrate the usefulness of these approaches in transit planning.
Received: September 2002 / Accepted: January 2003
This research was supported in part by an Ohio State University seed grant. 相似文献
3.
An integrated urban systems model with GIS 总被引：3，自引：0，他引：3
The main purpose of this paper is to explore a possible integration for the entire transportation modeling procedure – from
data inventory to future demand forecasting – by implementing integrated land use and transportation models with a geographic
information system (GIS). In order to make an integrated, procedural modeling system possible, Land Use and Transportation
modeling system with GIS (LUTGIS) has been developed and presented in this paper.
There are four sub-systems in LUTGIS: (1) a data inventory system, (2) a traffic analysis zone generation system, (3) an
integrated land use and transportation modeling system, and (4) a graphic user interface (GUI) system. Since the main target
of this paper is to explore a possible way to create a viable system, LUTGIS integrates currently available and user-friendly
computing technologies. For both transportation planners and administrative decision-makers, such an operable system is very
desirable for sharing information so they may arrive at a consensus through the use of LUTGIS, an integrated land use and
transportation modeling system.
Received: 22 October 1998/Accepted 11 July 1999 相似文献
4.
Change detection thresholds for remotely sensed images 总被引：4，自引：0，他引：4
Peter A. Rogerson 《Journal of Geographical Systems》2002,4(1):85-97
The detection of change in remotely sensed images is often carried out by designating a threshold to distinguish between
areas of change and areas of no change. The choice of threshold is often arbitrary however. The purpose of this paper is to
offer a statistical framework for the selection of thresholds. The framework accounts for the facts that one carries out multiple
tests of the null hypothesis of no change, when searching for regions of change over an image with a large number of pixels.
Special attention is given to global spatial autocorrelation, which can affect the selection of appropriate threshold values.
Received: 8 March 2001 / Accepted: 12 October 2001 相似文献
5.
Geostatistical incorporation of spatial coordinates into supervised classification of hyperspectral data 总被引：1，自引：0，他引：1
P. Goovaerts 《Journal of Geographical Systems》2002,4(1):99-111
This paper presents a methodology to incorporate both hyperspectral properties and spatial coordinates of pixels in maximum
likelihood classification. Indicator kriging of ground data is used to estimate, for each pixel, the prior probabilities of
occurrence of classes which are then combined with spectral-based probabilities within a Bayesian framework. In the case study
(mapping of in-stream habitats), accounting for spatial coordinates increases the overall producer's accuracy from 85.8% to
93.8%, while the Kappa statistic rises from 0.74 to 0.88. Best results are obtained using only indicator kriging-based probabilities,
with a stunning overall accuracy of 97.2%. Significant improvements are observed for environmentally important units, such
as pools (Kappa: 0.17 to 0.74) and eddy drop zones (Kappa: 0.65 to 0.87). The lack of benefit of using hyperspectral information
in the present study can be explained by the dense network of ground observations and the high spatial continuity of field
classification which might be spurious.
Received: 12 April 2001 / Accepted: 7 September 2001 相似文献
6.
Suppose that geographic data under investigation are rates associated with polygons. For example, disease incidence, mortality,
and census undercount data may be displayed as rates. Spatial analysis of data of this sort can be handled very naturally
through Bayesian hierarchical statistical modeling, where there is a measurement process at the first level, an explanatory
process at the second level, and a prior probability distribution on unknowns at the third level. In our paper, we shall feature
epidemiological data, specifically disease-incidence rates, and the “polygons” referred to in the title are typically states
or counties. 相似文献
7.
Aloys Borgers Frank Hofman Maarten Ponjé Harry Timmermans 《Journal of Geographical Systems》2001,3(4):347-367
None of the currently developed activity-based models of transport demand explicitly models task allocation among household
members. To fill this gap, the present paper suggests to complement activity-based models of activity scheduling with a context-dependent
model of task allocation. That is, it is assumed that the allocation of tasks within households is partly based on such contextual
variables as the amount of time a member has to spend on mandatory activities and car availability. In particular, the paper
advocates a conjoint-based approach, based on an assignment task as opposed to the traditional ranking, rating or choice response
formats. By definition, an assignment task involves a combinatorial explosion of choice alternatives, implying that additional
operational decisions to estimate the context-dependent model are required. This study presents the results of various numerical
experiments, conducted to better understand the impacts of those decisions on the degree of bias in the parameter estimates
of the choice model. The results of these simulations indicate that under particular assumptions, the development and estimation
of a conjoint-based, context-dependent model of task allocation within households is feasible.
Received: March 1999 / Accepted: June 2001 相似文献
8.
Richard Thomas 《Journal of Geographical Systems》2001,3(3):283-301
This paper applies a compartmental epidemic model to estimating the mixing relations that support the transfer of HIV infection
between risk populations within the countries of Western Europe. To this end, a space-time epidemic model with compartments
representing countries with populations specified to be at high (gay men and intravenous drug injectors ever with AIDS) and
low (the remainder who are sexually active) risk is described. This model also allows for contacts between susceptible and
infectious individuals by both local and international travel. This system is calibrated to recorded AIDS incidence and the
best-fit solution provides estimates of variations in the rates of mixing between the compartments together with a reconstruction
of the transmission pathway. This solution indicates that, for all the countries, AIDS incidence among those at low risk is
expected to remain extremely small relative to their total number. A sensitivity analysis of the low risk partner acquisition
rate, however, suggests this endemic state might be fragile within Europe during this century. The discussion examines the
relevance of these mixing relationships for the maintenance of disease control.
Received: 4 May 2000 / Accepted: 9 July 2000 相似文献
9.
Wolf-Dieter Rase 《Journal of Geographical Systems》2001,3(2):199-213
The interpolation of continuous surfaces from discrete points is supported by most GIS software packages. Some packages provide
additional options for the interpolation from 3D line objects, for example surface-specific lines, or contour lines digitized
from topographic maps. Demographic, social and economic data can also be used to construct and display smooth surfaces. The
variables are usually published as sums for polygonal units, such as the number of inhabitants in communities or counties.
In the case of point and line objects the geometric properties have to be maintained in the interpolated surface. For polygon-based
data the geometric properties of the polygon boundary and the volume should be preserved, avoiding redistribution of parts
of the volume to neighboring units during interpolation. The pycnophylactic interpolation method computes a continuous surface
from polygon-based data and simultaneously enforces volume preservation in the polygons. The original procedure using a regular
grid is extended to surface representations based on an irregular triangular network (TIN).
Received: 5 October 2000 / Accepted: 20 December 2000 相似文献
10.
Computer networks like the Internet are gaining importance in social and economic life. The accelerating pace of the adoption
of network technologies for business purposes is a rather recent phenomenon. Many applications are still in the early, sometimes
even experimental, phase. Nevertheless, it seems to be certain that networks will change the socioeconomic structures we know
today. This is the background for our special interest in the development of networks, in the role of spatial factors influencing
the formation of networks, and consequences of networks on spatial structures, and in the role of externalities. This paper
discusses a simple economic model – based on a microeconomic calculus – that incorporates the main factors that generate the
growth of computer networks. The paper provides analytic results about the generation of computer networks. The paper discusses
(1) under what conditions economic factors will initiate the process of network formation, (2) the relationship between individual
and social evaluation, and (3) the efficiency of a network that is generated based on economic mechanisms.
Received: 5 July 2000 / Accepted: 28 November 2000 相似文献
11.
Manfred M. Fischer 《Journal of Geographical Systems》2002,4(3):287-299
In this paper we view learning as an unconstrained non-linear minimization problem in which the objective function is defined
by the negative log-likelihood function and the search space by the parameter space of an origin constrained product unit
neural spatial interaction model. We consider Alopex based global search, as opposed to local search based upon backpropagation
of gradient descents, each in combination with the bootstrapping pairs approach to solve the maximum likelihood learning problem.
Interregional telecommunication traffic flow data from Austria are used as test bed for comparing the performance of the two
learning procedures. The study illustrates the superiority of Alopex based global search, measured in terms of Kullback and
Leibler's information criterion.
Received: December 2001 / Accepted: August 2002
The author gratefully thanks Martin Reismann (Department of Economic Geography & Geoinformatics) for his valuable research
assistance. 相似文献
12.
Giuseppe Arbia 《Journal of Geographical Systems》2001,3(3):271-281
Economists have recently devoted an increasing attention to the issue of spatial concentration of economic activities. However,
surprisingly enough, most of the empirical work is still based on the computation of very basic statistical measures in which
the geographical characteristics of data play no role. By making use of a series of empirical examples we show that spatial
concentration consists of two different features that are rarely kept as separate in the statistical analysis: an a-spatial
concept of variability which is invariant to permutations, and the concept of polarization that refers to the geographical
position of observations.
Received: 8 August 2000 / Accepted: 20 June 2001 相似文献
13.
Peter J.B. Brown Peter G. McCulloch Evelyn M.I. Williams Darren C. Ashurst 《Journal of Geographical Systems》2001,3(2):107-135
The development and application of an innovative sampling framework for use in a British study of the early detection of
gastric cancer are described. The Super Profiles geodemographic discriminator is used in the identification of geographically
distinct control and contrast areas from which samples of cancer registry case records may be drawn for comparison with the
records of patients participating in the gastric cancer intervention project. Preliminary results of the application of the
framework are presented and confirm its effectiveness in satisfactorily reflecting known patterns of variation in cancer occurrence
by age, gender and social class. The method works well for cancers with a known and clear social gradient, such as lung and
breast cancer, moderately well for gastric cancer and somewhat less well for oesophageal cancer, where the social class gradient
is less clear.
Received: 1 January 2000 / Accepted: 18 September 2000 相似文献
14.
This paper develops a computational method for analyzing changes in polygon distributions. Unmovable polygons that change
discontinuously without explicit functional linkage information are discussed. Six types of primitive events are used to describe
the change: 1) generation, 2) disappearance, 3) expansion, 4) shrinkage, 5) union, and 6) division. The change of polygon
distributions is decomposed into a combination of these events. A computational procedure for deducing a set of events from
polygon distributions of two times is proposed. The method is applied to the analysis of the spatial competition between the
major and small chains of convenience stores in Tokyo, Japan. Some empirical findings are shown.
Received: 3 August 2000 / Accepted: 6 February 2001 相似文献
15.
Spatial statistical techniques for aggregating point objects extracted from high spatial resolution remotely sensed imagery 总被引：3，自引：0，他引：3
Trisalyn Nelson K. Olaf Niemann Michael A. Wulder 《Journal of Geographical Systems》2002,4(4):423-433
Using a local maximum filter, individual trees were extracted from a 1 m spatial resolution IKONOS image and represented
as points. The spatial pattern of individual trees was determined to represent forest age (a surrogate for forest structure).
Point attributes, based on the spatial pattern of trees, were generated via nearest neighbour statistics and used as the basis
for aggregating points into forest structure units. The forest structure units allowed for the mapping of a forested area
into one of three age categories: young (1–20 years), intermediate (21–120 years), and mature (>120 years). This research
indicates a new approach to image processing, where objects generated from the processing of image data (rather than pixels
or spectral values) are subjected to spatial statistical analysis to estimate an attribute relating an aspect of forest structure.
Received: 22 April 2002 / Accepted: 23 November 2002 相似文献
16.
Schistosomiasis is a serious public health problem in the middle-lower Yangtze River Basin in China. Study of spatial variation
of snail distribution that is related to microgeographic factors can help to choose pertinent measures for snail extinguishment
and environment rebuilding. This paper studied the theoretical architecture of weights-of-evidence approach. The case study
was made for spatial relation between the occurrence of infected snails and geographic factor combinations in Waijiazhou marshland
of Poyang Lake region in China. The multievidence data came from the geographical factor combinations by crossing operation
of vegetation coverage grade layer, cattle route distance grade layer, and special environment layer (181 combinations in
total) in GIS. The calculation of weight contrast index shows that high vegetation coverage, cattle route distance of <45
meters, and special geographic factor “ground depression” had direct spatial relation with the occurrence of infected snails.
The verification by crossing operation in GIS indicated 72.45% of the infected snails concentrated on the areas of positive
weight contrast index (sequenced in an order of weight contrast index from high to low), demonstrating the high efficiency
of the model established in finding infected snails according to the geographic factor combinations that can be explicitly
discerned in the study area.
Supported by a the National Natural Science Fundation of China (No. 30590370), the Research Project “Spatial Simulation of
Schistosomiasis Susceptible Areas in the Poyang Lake Region” Sponsored by Science Research Plan 2007 of Jiangxi Normal University
(Natural Science Category). 相似文献
17.
Jean H.P. Paelinck 《Journal of Geographical Systems》2002,4(4):371-383
Links between socio-economic units have been studied by means of various techniques. This study analyses networks that take
on a permanently growing importance in evolutionary economics. The analysis is conducted in a sequential way on matrices picturing
the intensities of certain relations; the technique used is linear assignment. The latter is first applied to matrices of
socio-economic relations set up for the Netherlands and Portugal; the various types of “networking” present could be revealed
and compared. Medical activities, taken in their socio-economic setting, rest also on various networks ; available matrices
for the Netherlands are submitted to the above method of analysis. Moreover, a classical input-output matrix for the United
Kingdom is used as a last test for the validity of the method.
Received: 1 March 2002 / Accepted: 19 November 2002 相似文献
18.
Daniel A. Griffith 《Journal of Geographical Systems》2002,4(1):43-51
As either the spatial resolution or the spatial scale for a geographic landscape increases, both latent spatial dependence
and spatial heterogeneity also will tend to increase. In addition, the amount of georeferenced data that results becomes massively
large. These features of high spatial resolution hyperspectral data present several impediments to conducting a spatial statistical
analysis of such data. Foremost is the requirement of popular spatial autoregressive models to compute eigenvalues for a row-standardized
geographic weights matrix that depicts the geographic configuration of an image's pixels. A second drawback arises from a
need to account for increased spatial heterogeneity. And a third concern stems from the usefulness of marrying geostatistical
and spatial autoregressive models in order to employ their combined power in a spatial analysis. Research reported in this
paper addresses all three of these topics, proposing successful ways to prevent them from hindering a spatial statistical
analysis. For illustrative purposes, the proposed techniques are employed in a spatial analysis of a high spatial resolution
hyperspectral image collected during research on riparian habitats in the Yellowstone ecosystem.
Received: 25 February 2001 / Accepted: 2 August 2001 相似文献
19.
20.
Yoshiaki Ohsawa Hirofumi Kagaya Takeshi Koshizuka 《Journal of Geographical Systems》2002,4(3):325-342
When demand points are given as a planar map where projection method is explicitly stated, we usually know the latitudes
and longitudes of these points from the map. Then we can solve the Weber problem on the globe, and we do not suffer from errors.
This paper analyses how cylindrical projections cause distortion in the Weber problem when demands are distributed on the
Northern Hemisphere. First, we demonstrate that planar solutions are always located south of the spherical solution if the
Mercator projection, the equirectangular projections with standard parallels near the demands, or the equal-area projection
with the same characteristic is chosen. Second, we verify that this geographical tendency is inclined to hold when the demand
points, are distributed symmetrically, widely or toward the north.
Received: 15 August 2001 / Accepted: 20 April 2002
This paper was partially written while the first author was visiting the Department of Geography at the Catholic University
of Louvain, Louvain-la-Neuve, Belgium [1993–1994]. He is grateful for the hospitality of this department. An earlier version
of this paper was presented in 1994 at the Seventh Meeting of the European Operational Research Working Group on Locational
Analysis in Brussels, and in 1996 at the Fifth World Congress of the Regional Science Association International in Tokyo.
The authors would also like to thank the participants as well as three anonymous referees for their constructive comments. 相似文献