System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability po...System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability policies to practice. This is largely because the challenge of including spatial data has not yet been well met. Potential for adoption of SD and GIS methods in combination is exemplified with the results of a decision-support exercise designed for simulation and prediction of the dynamic inter-relationships between socio-economic development and environmental quality for the "Wen, Pi, Du" county in Sichuan province, southwestern China.展开更多
There are mainly four kinds of models to record and deal with historical information.By taking them as reference,the spatio-temporal model based on event semantics is proposed.In this model,according to the way for de...There are mainly four kinds of models to record and deal with historical information.By taking them as reference,the spatio-temporal model based on event semantics is proposed.In this model,according to the way for describing an event,all the information are divided into five domains.This paper describes the model by using the land parcel change in the cadastral information system,and expounds the model by using five tables corresponding to the five domains.With the aid of this model,seven examples are given on historical query,trace back and recurrence.This model can be implemented either in the extended relational database or in the object-oriented database.展开更多
This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together wi...This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together with non_spatial fundamental database.Data composition and reasoning are two key steps of 4D data fusion.Finally,this paper gives a real case: Ezhou Waterlog_Draining Decision Support System (EWDSS) with two application models,i.e.,DEM application model,water generating and draining model.展开更多
Mineral resource potential mapping is a complex analytical process,which requires the consideration and the inte-gration of a number of spatial evidences like geological,geomorphological,and wall rock alteration.The a...Mineral resource potential mapping is a complex analytical process,which requires the consideration and the inte-gration of a number of spatial evidences like geological,geomorphological,and wall rock alteration.The aim of this paper is to establish mineral exploration model for copper,lead,and zinc in Lanping basin area using the capability of analytical tools of Geographic Information System(GIS) and remote sensing data to generate maps showing favorable mineralized area.The geo-exploration dataset used for the research includes copper,lead,and zinc deposits,geological maps,topographic maps,structural maps,and ETM+ imagery.Geological features indicative of potential copper,lead,and zinc were extracted from the datasets input in the predictive model.The method of weights of evidence modeling is a probability-based technique for generating mineral potential maps using the spatial distribution of indicative features with respect to the known mineral occur-rences.The method of weights of evidence probabilistic modeling provides a quantitative method for delineating areas with potential of copper,lead,and zinc mineral deposits in the Lanping Basin area.weights(W+,W-) and contrast(C=(W+) -(W-) ) calculations guide the data-driven modeling.The four most important spatial features for exploration guide for copper,lead,and zinc mineralization hosted in the Lanping Basin area are alteration zones,faults,host rocks,and lineaments.The host rocks and deep faults have the strongest spatial association with the known copper,lead,and zinc deposits.The hydrothermal alteration zones have the moderate spatial association with the copper,lead,and zinc deposits.The predicted high-favorability zones do not show the strong affinity with lineaments.The distribution of 22(copper,lead,and zinc) occur-rences in the Lanping Basin was examined in terms of spatial association with various geological phenomena.The analysis of these relationships using GIS and weights of evidence modeling has predicted areas of high and moderate mineral potential,where a little or no mining activities exist.展开更多
A method for mining frequent itemsets by evaluating their probability of supports based on asso-ciation analysis is presented.This paper obtains the probability of every 1-itemset by scanning the database,then evaluat...A method for mining frequent itemsets by evaluating their probability of supports based on asso-ciation analysis is presented.This paper obtains the probability of every 1-itemset by scanning the database,then evaluates the probability of every 2-itemset,every 3-itemset,every k-itemset from the frequent 1-itemsets and gains all the candidate frequent itemsets.This paper also scans the database for verifying the support of the candidate frequent itemsets.Last,the frequent itemsets are mined.The method reduces a lot of time of scanning database and shortens the computation time of the algorithm.展开更多
This paper discusses methods for character extraction on the basis of statistical and structural features of gray_level images,and proposes a dynamic local contrast threshold method accommodating to line width.Precise...This paper discusses methods for character extraction on the basis of statistical and structural features of gray_level images,and proposes a dynamic local contrast threshold method accommodating to line width.Precise locating of character string is realized by exploiting horizontal projection and character arrangements of binary images in horizontal and vertical directions respectively.Also discussed is the method for segmentation of characters in binary images,which is based on projection taking stroke width and character sizes into account.A new method for character identification is explored,which is based on compound neural networks.A complex neural network consists of two sub_nets,the first sub_net performs self_association of patterns via 2_dimentional local_connected 3_order networks,the second sub_net,linking with a locally connected BP networks,performs classification.The reliability of the network recognition is reinforced by introducing conditions for identification denial.Experiments confirm that the proposed methods possess the advantages of impressive robustness,rapid processing and high accuracy of identification.展开更多
This paper introduces some definitions and defines a set of calculating indexes to facilitate the research,and then presents an algorithm to complete the spatial clustering result comparison between different clusteri...This paper introduces some definitions and defines a set of calculating indexes to facilitate the research,and then presents an algorithm to complete the spatial clustering result comparison between different clustering themes.The research shows that some valuable spatial correlation patterns can be further found from the clustering result comparison with multi-themes,based on traditional spatial clustering as the first step.Those patterns can tell us what relations those themes have,and thus will help us have a deeper understanding of the studied spatial entities.An example is also given to demonstrate the principle and process of the method.展开更多
This paper proposes the principle of comprehensive knowledge discovery.Unlike most of the current knowledge discovery methods,the comprehensive knowledge discovery considers both the spatial relations and attributes o...This paper proposes the principle of comprehensive knowledge discovery.Unlike most of the current knowledge discovery methods,the comprehensive knowledge discovery considers both the spatial relations and attributes of spatial entities or objects.We introduce the theory of spatial knowledge expression system and some concepts including comprehensive knowledge discovery and spatial union information table(SUIT).In theory,SUIT records all information contained in the studied objects,but in reality,because of the complexity and varieties of spatial relations,only those factors of interest to us are selected.In order to find out the comprehensive knowledge from spatial databases,an efficient comprehensive knowledge discovery algorithm called recycled algorithm(RAR)is suggested.展开更多
With the rapid development of computer graphics,distributed-computing and Internet,it is possible to achieve Internet-based virtual city.This paper dwells on the method of the terrain and its feature modeling and comp...With the rapid development of computer graphics,distributed-computing and Internet,it is possible to achieve Internet-based virtual city.This paper dwells on the method of the terrain and its feature modeling and complex entity modeling in the virtual city.Then,discusses the method for Internet-based virtual city 3D visualization and the design of the Browser/Server architecture of the system of virtual city in the network environment.Finally,Java and Java 3D are used to show an experiment example,and the related conclusion about Internet-based virtual city 3D displaying and the client-side interactive operation is given.展开更多
In this paper,the entity_relation data model for integrating spatio_temporal data is designed.In the design,spatio_temporal data can be effectively stored and spatiao_temporal analysis can be easily realized.
3D GISs were developed simultaneously in the late 1980s in a number of different disciplines.The development of these 3D GISs can not yet meet all needs for new representations and analytical tool s in 3D envir onment...3D GISs were developed simultaneously in the late 1980s in a number of different disciplines.The development of these 3D GISs can not yet meet all needs for new representations and analytical tool s in 3D envir onments.In this paper,the data structures,especially solid-based data representa tions are introduced.Then,a typical object-oriented data model is put forth to s how a new data model.And at last,two data access methods are proposed to make th e data model clear.展开更多
This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane.After the method,aerial images match known DEM to capture the...This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane.After the method,aerial images match known DEM to capture the spatial position and posture.Some aerial images and terrain data are used to testify our method.Compared with those of analytic and stereo mappers,the results by our method are correspondent to real measurements well.展开更多
文摘System dynamics (SD) theory has long been deployed in modeling complex non-linear interrelationships but, so far it has not been common to do the kind of modeling in support of bringing environmental sustainability policies to practice. This is largely because the challenge of including spatial data has not yet been well met. Potential for adoption of SD and GIS methods in combination is exemplified with the results of a decision-support exercise designed for simulation and prediction of the dynamic inter-relationships between socio-economic development and environmental quality for the "Wen, Pi, Du" county in Sichuan province, southwestern China.
文摘There are mainly four kinds of models to record and deal with historical information.By taking them as reference,the spatio-temporal model based on event semantics is proposed.In this model,according to the way for describing an event,all the information are divided into five domains.This paper describes the model by using the land parcel change in the cadastral information system,and expounds the model by using five tables corresponding to the five domains.With the aid of this model,seven examples are given on historical query,trace back and recurrence.This model can be implemented either in the extended relational database or in the object-oriented database.
文摘This paper studies urban waterlog_draining decision support system based on the 4D data fusion technique.4D data includes DEM,DOQ,DLG and DRG.It supplies entire databases for waterlog forecast and analysis together with non_spatial fundamental database.Data composition and reasoning are two key steps of 4D data fusion.Finally,this paper gives a real case: Ezhou Waterlog_Draining Decision Support System (EWDSS) with two application models,i.e.,DEM application model,water generating and draining model.
文摘Mineral resource potential mapping is a complex analytical process,which requires the consideration and the inte-gration of a number of spatial evidences like geological,geomorphological,and wall rock alteration.The aim of this paper is to establish mineral exploration model for copper,lead,and zinc in Lanping basin area using the capability of analytical tools of Geographic Information System(GIS) and remote sensing data to generate maps showing favorable mineralized area.The geo-exploration dataset used for the research includes copper,lead,and zinc deposits,geological maps,topographic maps,structural maps,and ETM+ imagery.Geological features indicative of potential copper,lead,and zinc were extracted from the datasets input in the predictive model.The method of weights of evidence modeling is a probability-based technique for generating mineral potential maps using the spatial distribution of indicative features with respect to the known mineral occur-rences.The method of weights of evidence probabilistic modeling provides a quantitative method for delineating areas with potential of copper,lead,and zinc mineral deposits in the Lanping Basin area.weights(W+,W-) and contrast(C=(W+) -(W-) ) calculations guide the data-driven modeling.The four most important spatial features for exploration guide for copper,lead,and zinc mineralization hosted in the Lanping Basin area are alteration zones,faults,host rocks,and lineaments.The host rocks and deep faults have the strongest spatial association with the known copper,lead,and zinc deposits.The hydrothermal alteration zones have the moderate spatial association with the copper,lead,and zinc deposits.The predicted high-favorability zones do not show the strong affinity with lineaments.The distribution of 22(copper,lead,and zinc) occur-rences in the Lanping Basin was examined in terms of spatial association with various geological phenomena.The analysis of these relationships using GIS and weights of evidence modeling has predicted areas of high and moderate mineral potential,where a little or no mining activities exist.
基金Funded by the National 973 Project(No.2003CB415205).
文摘A method for mining frequent itemsets by evaluating their probability of supports based on asso-ciation analysis is presented.This paper obtains the probability of every 1-itemset by scanning the database,then evaluates the probability of every 2-itemset,every 3-itemset,every k-itemset from the frequent 1-itemsets and gains all the candidate frequent itemsets.This paper also scans the database for verifying the support of the candidate frequent itemsets.Last,the frequent itemsets are mined.The method reduces a lot of time of scanning database and shortens the computation time of the algorithm.
文摘This paper discusses methods for character extraction on the basis of statistical and structural features of gray_level images,and proposes a dynamic local contrast threshold method accommodating to line width.Precise locating of character string is realized by exploiting horizontal projection and character arrangements of binary images in horizontal and vertical directions respectively.Also discussed is the method for segmentation of characters in binary images,which is based on projection taking stroke width and character sizes into account.A new method for character identification is explored,which is based on compound neural networks.A complex neural network consists of two sub_nets,the first sub_net performs self_association of patterns via 2_dimentional local_connected 3_order networks,the second sub_net,linking with a locally connected BP networks,performs classification.The reliability of the network recognition is reinforced by introducing conditions for identification denial.Experiments confirm that the proposed methods possess the advantages of impressive robustness,rapid processing and high accuracy of identification.
文摘This paper introduces some definitions and defines a set of calculating indexes to facilitate the research,and then presents an algorithm to complete the spatial clustering result comparison between different clustering themes.The research shows that some valuable spatial correlation patterns can be further found from the clustering result comparison with multi-themes,based on traditional spatial clustering as the first step.Those patterns can tell us what relations those themes have,and thus will help us have a deeper understanding of the studied spatial entities.An example is also given to demonstrate the principle and process of the method.
基金the China’s National Surveying Technical Fund(No.20007)
文摘This paper proposes the principle of comprehensive knowledge discovery.Unlike most of the current knowledge discovery methods,the comprehensive knowledge discovery considers both the spatial relations and attributes of spatial entities or objects.We introduce the theory of spatial knowledge expression system and some concepts including comprehensive knowledge discovery and spatial union information table(SUIT).In theory,SUIT records all information contained in the studied objects,but in reality,because of the complexity and varieties of spatial relations,only those factors of interest to us are selected.In order to find out the comprehensive knowledge from spatial databases,an efficient comprehensive knowledge discovery algorithm called recycled algorithm(RAR)is suggested.
文摘With the rapid development of computer graphics,distributed-computing and Internet,it is possible to achieve Internet-based virtual city.This paper dwells on the method of the terrain and its feature modeling and complex entity modeling in the virtual city.Then,discusses the method for Internet-based virtual city 3D visualization and the design of the Browser/Server architecture of the system of virtual city in the network environment.Finally,Java and Java 3D are used to show an experiment example,and the related conclusion about Internet-based virtual city 3D displaying and the client-side interactive operation is given.
基金Project supported by the National Surveying Technical Fund(No.200_07)
文摘In this paper,the entity_relation data model for integrating spatio_temporal data is designed.In the design,spatio_temporal data can be effectively stored and spatiao_temporal analysis can be easily realized.
文摘3D GISs were developed simultaneously in the late 1980s in a number of different disciplines.The development of these 3D GISs can not yet meet all needs for new representations and analytical tool s in 3D envir onments.In this paper,the data structures,especially solid-based data representa tions are introduced.Then,a typical object-oriented data model is put forth to s how a new data model.And at last,two data access methods are proposed to make th e data model clear.
基金uisition of Directional Funded by the National 973 Project(No.2003CB415205).
文摘This paper develops a method which can be used to assist aerial navigation by determining the spatial position and posture of the aerial photographic plane.After the method,aerial images match known DEM to capture the spatial position and posture.Some aerial images and terrain data are used to testify our method.Compared with those of analytic and stereo mappers,the results by our method are correspondent to real measurements well.
