GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher ...GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher levels. There is no uniform platform that can be used to manage all involved maps. The main reason for this is that datasets are submitted by individual coal mines using their individual, diverse software. No consistent model is used within the software for data abstraction and symbolization. This paper first reviews all the essential specifications concerning OGC (Open Geospatial Consortium) interoperability. Then an OGC standard-oriented architecture is proposed to provide distributed coal mine map services. Within this new architecture the management of spatial data archives, and the integration of coal mine maps, are achieved through the interfaces of geospatial services. Finally an open source geospatial approach is suggested to implement the proposed scheme. A case study of the Huaibei Coal Group is used to demonstrate the proposal.展开更多
The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G...The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.展开更多
OGC Web Map Service is one kind of OGC Portrayal Services belongs to OGC Web Service model and it provides multi\|platform interoperability of spatial data set. This paper presents a method for implementing OGC Web Ma...OGC Web Map Service is one kind of OGC Portrayal Services belongs to OGC Web Service model and it provides multi\|platform interoperability of spatial data set. This paper presents a method for implementing OGC Web Map Service based on Web Service technique and introduces the detailed process.展开更多
Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented f...Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented for its proactive remanufacturing with setting up to explore the best remanufacturing time point in this work.Considering a certain model of long distance pipeline compressor impeller with the Basquin equation and the design method of impeller,the mathematical relationship between the changes of structure and life of the impeller was established.And the service mapping model between the structure and life was set up and simulated by ANSYS software.Thus,the service mapping model was applied to feedback the original design for proactive remanufacturing.In this work,the best proactive remanufacturing time point of impeller was analyzed with the service mapping model,and the structural parameter values could be optimized at this time point.Meanwhile,in the results of this simulation,it proves that the impeller under this optimization performance could satisfy the impeller operating demands.Therefore,comparing with the traditional optimization design method,the remanufacturing optimized design based on the service mapping model is feasible in proactive remanufacturing for sustainable development.展开更多
Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and effic...Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi* statistics, we quantified the variation of annual soil conservation services (SC) and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1) areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2) SC hotspots and coldspots showed an obvious spatial differentiation--the hotspots were mainly spatially ag- gregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3) the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi* statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity.展开更多
Service function chains(SFC)mapping takes the responsibility for managing virtual network functions(VNFs).In SFC mapping,existing solutions duplicate VNFs with redundant instances to provide high availability in respo...Service function chains(SFC)mapping takes the responsibility for managing virtual network functions(VNFs).In SFC mapping,existing solutions duplicate VNFs with redundant instances to provide high availability in response to failures.However,as a compromise,these solutions result in high resource consumption due to device maintenance.In this paper,we propose a novel method named dynamic backup sharing(DBS)that allows SFCs to dynamically share backups to reduce resource consumption.DBS formulates the problem of sharing backups among different VNFs as an integer linear programming(ILP).Thereafter,we design a novel online algorithm based on dynamic programming to solve the problem.The experimental results indicate that DBS outperforms state-ofthe-art works by reducing resource consumption and improving the number of accepted requests.展开更多
With the burgeoning emphasis on sustainable construction practices in China,the demand for green building assessment has significantly escalated.The overall evaluation process comprises two key components:The acquisit...With the burgeoning emphasis on sustainable construction practices in China,the demand for green building assessment has significantly escalated.The overall evaluation process comprises two key components:The acquisition of evaluation data and the evaluation of green scores,both of which entail considerable time and effort.Previous research predominantly concentrated on automating the latter process,often neglecting the exploration of automating the former in accordance with the Chinese green building assessment system.Furthermore,there is a pressing requirement for more streamlined management of structured standard knowledge to facilitate broader dissemination.In response to these challenges,this paper presents a conceptual framework that integrates building information modeling,ontology,and web map services to augment the efficiency of the overall evaluation process and the management of standard knowledge.More specifically,in accordance with the Assessment Standard for Green Building(GB/T 50378-2019)in China,this study innovatively employs visual programming software,Dynamo in Autodesk Revit,and the application programming interface of web map services to expedite the acquisition of essential architectural data and geographic information for green building assessment.Subsequently,ontology technology is harnessed to visualize the management of standard knowledge related to green building assessment and to enable the derivation of green scores through logical reasoning.Ultimately,a residential building is employed as a case study to validate the theoretical and technical feasibility of the developed automated evaluation conceptual framework for green buildings.The research findings hold valuable utility in providing a self-assessment method for applicants in the field.展开更多
Context:Without clear understanding of the units used for ecosystem service(ES)mapping,ES assessment accuracy and the practical application of ES knowledge will be hampered.Method:We systematically reviewed 106 studie...Context:Without clear understanding of the units used for ecosystem service(ES)mapping,ES assessment accuracy and the practical application of ES knowledge will be hampered.Method:We systematically reviewed 106 studies over the past 11 years to explore the type,characteristic pattern and deficiencies of mapping units.Result:We proposed that ES mapping units can be categorized into minimal unit for assessing ESs using corresponding indicators and methods,and aggregated unit for analysis and application based on research objectives,and classified the mapping units into five common types.Of the 12 characterizing variables of ES mapping studies,some have been shown to introduce a difference in the selection of mapping units and to exhibit characteristic patterns.We also found that the accuracy of ES assessments based on minimal units was lacking,and aggregated units were insufficient to establish a link between ES knowledge and practice.Conclusion:Herein,we propose possible solutions such as the use of fine spatial resolution grids and the introduction of additional data beyond land cover as supplements to improve the assessment accuracy.To enhance the availability of the results for practice,aggregated units connected with urban planning units should be established at a spatial level suitable for urban management.展开更多
In this research,we analyzed the delivery service areas of restaurants,customer satisfaction,and restaurant sales of urban restaurants during the COVID-19 pandemic.We obtained the datasets on food ordering options and...In this research,we analyzed the delivery service areas of restaurants,customer satisfaction,and restaurant sales of urban restaurants during the COVID-19 pandemic.We obtained the datasets on food ordering options and restaurant rankings based on Google Maps,Open Street Map,and widely known online food order applications in Iran.Based on this analysis we further modeled suitable areas for future extension of restaurants.We analyzed the online food order data of restaurants’sales and food delivery reports for 1050 restaurants in the city of Tabriz.We collected and analyzed data on the restaurant locations,the number of food orders for each restaurant,and the number of customers and their locations.Our results revealed that the spatial dimension of the newly emerging food delivery areas is of utmost importance for the success of restaurants.This indicates that an optimal location is not longer only dependent on factors like population density and competitors in the direct vicinity but on the services density even from more distant competitors.The results indicate that an optimized spatial distribution of the restaurants together with efficient quality in services can contribute to optimistic urban development.展开更多
Digital Earth is an information expression of the real Earth,and is a new way of understanding the Earth in the twenty-first century.This paper introduces a Digital Earth Prototype System(DEPS)developed at the Chinese...Digital Earth is an information expression of the real Earth,and is a new way of understanding the Earth in the twenty-first century.This paper introduces a Digital Earth Prototype System(DEPS)developed at the Chinese Academy of Sciences(CAS)and supported by the Knowledge Innovation Program of the Chinese Academy of Sciences.Discussions are made to the theoretical model and technical framework of the Digital Earth,and its related key technologies on spatial information processing,spatial data warehouse technology,virtual reality technology,high-performance and parallel computing.The DEPS consists of seven sub-systems including the spatial data,metadata,model database,Grid geoscience computing,spatial information database,maps service and virtual reality.Meanwhile,we developed a series of application systems such as the environment monitoring for the Olympic Games 2008 in Beijing,natural disasters evaluation,digital city,digital archeology,Asia regional aerosol and climate change.The DEPS/CAS displayed the application ability and potential of the Digital Earth in three levels:the global,national and regional.展开更多
Without explicit description of map application themes,it is difficult for users to discover desired map resources from massive online Web Map Services(WMS).However,metadata-based map application theme extraction is a...Without explicit description of map application themes,it is difficult for users to discover desired map resources from massive online Web Map Services(WMS).However,metadata-based map application theme extraction is a challenging multi-label text classification task due to limited training samples,mixed vocabularies,variable length and content arbitrariness of text fields.In this paper,we propose a novel multi-label text classification method,Text GCN-SW-KNN,based on geographic semantics and collaborative training to improve classifica-tion accuracy.The semi-supervised collaborative training adopts two base models,i.e.a modified Text Graph Convolutional Network(Text GCN)by utilizing Semantic Web,named Text GCN-SW,and widely-used Multi-Label K-Nearest Neighbor(ML-KNN).Text GCN-SW is improved from Text GCN by adjusting the adjacency matrix of the heterogeneous word document graph with the shortest semantic distances between themes and words in metadata text.The distances are calculated with the Semantic Web of Earth and Environmental Terminology(SWEET)and WordNet dictionaries.Experiments on both the WMS and layer metadata show that the proposed methods can achieve higher F1-score and accuracy than state-of-the-art baselines,and demonstrate better stability in repeating experiments and robustness to less training data.Text GCN-SW-KNN can be extended to other multi-label text classification scenario for better supporting metadata enhancement and geospatial resource discovery in Earth Science domain.展开更多
The volume of publically available geospatial data on the web is rapidly increasing due to advances in server-based technologies and the ease at which data can now be created.However,challenges remain with connecting ...The volume of publically available geospatial data on the web is rapidly increasing due to advances in server-based technologies and the ease at which data can now be created.However,challenges remain with connecting individuals searching for geospatial data with servers and websites where such data exist.The objective of this paper is to present a publically available Geospatial Search Engine(GSE)that utilizes a web crawler built on top of the Google search engine in order to search the web for geospatial data.The crawler seeding mechanism combines search terms entered by users with predefined keywords that identify geospatial data services.A procedure runs daily to update map server layers and metadata,and to eliminate servers that go offline.The GSE supports Web Map Services,ArcGIS services,and websites that have geospatial data for download.We applied the GSE to search for all available geospatial services under these formats and provide search results including the spatial distribution of all obtained services.While enhancements to our GSE and to web crawler technology in general lie ahead,our work represents an important step toward realizing the potential of a publically accessible tool for discovering the global availability of geospatial data.展开更多
基金Project 40771167 supported by the National Natural Science Foundation of China
文摘GIS- or CAD-based technology has been widely used for cartographic maps in coal mines, but structural gaps between such maps make it difficult to provide an integrated map service, for any specific purpose, at higher levels. There is no uniform platform that can be used to manage all involved maps. The main reason for this is that datasets are submitted by individual coal mines using their individual, diverse software. No consistent model is used within the software for data abstraction and symbolization. This paper first reviews all the essential specifications concerning OGC (Open Geospatial Consortium) interoperability. Then an OGC standard-oriented architecture is proposed to provide distributed coal mine map services. Within this new architecture the management of spatial data archives, and the integration of coal mine maps, are achieved through the interfaces of geospatial services. Finally an open source geospatial approach is suggested to implement the proposed scheme. A case study of the Huaibei Coal Group is used to demonstrate the proposal.
基金the National Key R&D Program of China(Grant No.2022YFF0503702)the National Natural Science Foundation of China(Grant Nos.42074186,41831071,42004136,and 42274195)+1 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20211036)the Specialized Research Fund for State Key Laboratories,and the University of Science and Technology of China Research Funds of the Double First-Class Initiative(Grant No.YD2080002013).
文摘The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions.
文摘OGC Web Map Service is one kind of OGC Portrayal Services belongs to OGC Web Service model and it provides multi\|platform interoperability of spatial data set. This paper presents a method for implementing OGC Web Map Service based on Web Service technique and introduces the detailed process.
基金Project(2011CB013406)supported by National Basic Research Program of ChinaProjects(51305119,51375133)supported by National Natural Science Foundation of China
文摘Since the complex impeller structure and the difficult remanufacturing process may easily cause advance remanufacturing or excessive use,an optimized design method of impeller and service mapping model was presented for its proactive remanufacturing with setting up to explore the best remanufacturing time point in this work.Considering a certain model of long distance pipeline compressor impeller with the Basquin equation and the design method of impeller,the mathematical relationship between the changes of structure and life of the impeller was established.And the service mapping model between the structure and life was set up and simulated by ANSYS software.Thus,the service mapping model was applied to feedback the original design for proactive remanufacturing.In this work,the best proactive remanufacturing time point of impeller was analyzed with the service mapping model,and the structural parameter values could be optimized at this time point.Meanwhile,in the results of this simulation,it proves that the impeller under this optimization performance could satisfy the impeller operating demands.Therefore,comparing with the traditional optimization design method,the remanufacturing optimized design based on the service mapping model is feasible in proactive remanufacturing for sustainable development.
基金National Natural Science Foundation of China, No.41601182 National Social Science Foundation of China, No.14AZD094+3 种基金 National Key Research and Development Plan of China, No.2016YFC0501601 China Postdoctoral Science Foundation, No.2016M592743 Fundamental Research Funds for the Central Universities, No.GK201603078 Key Project of the Ministry of Education of China, No. 15JJD790022Acknowledgments We are grateful to the anonymous reviewers for their constructive advice about the paper, and we also thank Chen Guoyong from the Hunan University, who provided important aid in calculating the annual soil conservation of Shaanxi by MATLAB programming.
文摘Spatial-explicitly mapping of the hotspots and coldspots is a vital link in the priority setting for ecosystem services (ES) conservation. However, little research has identified and tested the compactness and efficiency of their ES hotspots and coldspots, which may weaken the effectiveness of ecological conservation. In this study, based on the RUSLE model and Getis-Ord Gi* statistics, we quantified the variation of annual soil conservation services (SC) and identified the statistically significant hotspots and coldspots in Shaanxi Province of China from 2000 to 2013. The results indicate that, 1) areas with high SC presented a significantly increasing trend as well, while areas with low SC only changed slightly; 2) SC hotspots and coldspots showed an obvious spatial differentiation--the hotspots were mainly spatially ag- gregated in southern Shaanxi, while the coldspots were mainly distributed in the Guanzhong Basin and Sand-windy Plateau; and 3) the identified hotspots had the highest capacity of providing SC, with 29.6% of the total area providing 59.7% of the total service. In contrast, the coldspots occupied 46.3% of the total area, but only provided 17.2% of the total SC. In addition to conserving single ES, the Getis-Ord Gi* statistics method can also help identify multi-functional priority areas for conserving multiple ES and biodiversity.
基金This work is supported by the National Key R&D Program of China(2018YFB1800601)the Key R&D Program of Zhejiang Province(2021C01036,2020C01021)the Fundamental Research Funds for the Central Universities(Zhejiang University NGICS Platform:ZJUNGICS2021021).
文摘Service function chains(SFC)mapping takes the responsibility for managing virtual network functions(VNFs).In SFC mapping,existing solutions duplicate VNFs with redundant instances to provide high availability in response to failures.However,as a compromise,these solutions result in high resource consumption due to device maintenance.In this paper,we propose a novel method named dynamic backup sharing(DBS)that allows SFCs to dynamically share backups to reduce resource consumption.DBS formulates the problem of sharing backups among different VNFs as an integer linear programming(ILP).Thereafter,we design a novel online algorithm based on dynamic programming to solve the problem.The experimental results indicate that DBS outperforms state-ofthe-art works by reducing resource consumption and improving the number of accepted requests.
基金funded by National Natural Science Foundation of China(Grant Nos.72371171 and 72001148)Programme of Shenzhen Key Laboratory of Green,Efficient and Intelligent Construction of Underground Metro Station(Grant No.ZDSYS20200923105200001).
文摘With the burgeoning emphasis on sustainable construction practices in China,the demand for green building assessment has significantly escalated.The overall evaluation process comprises two key components:The acquisition of evaluation data and the evaluation of green scores,both of which entail considerable time and effort.Previous research predominantly concentrated on automating the latter process,often neglecting the exploration of automating the former in accordance with the Chinese green building assessment system.Furthermore,there is a pressing requirement for more streamlined management of structured standard knowledge to facilitate broader dissemination.In response to these challenges,this paper presents a conceptual framework that integrates building information modeling,ontology,and web map services to augment the efficiency of the overall evaluation process and the management of standard knowledge.More specifically,in accordance with the Assessment Standard for Green Building(GB/T 50378-2019)in China,this study innovatively employs visual programming software,Dynamo in Autodesk Revit,and the application programming interface of web map services to expedite the acquisition of essential architectural data and geographic information for green building assessment.Subsequently,ontology technology is harnessed to visualize the management of standard knowledge related to green building assessment and to enable the derivation of green scores through logical reasoning.Ultimately,a residential building is employed as a case study to validate the theoretical and technical feasibility of the developed automated evaluation conceptual framework for green buildings.The research findings hold valuable utility in providing a self-assessment method for applicants in the field.
基金This work was supported by the China National R&D Program under grant number 2017YFC0505705.
文摘Context:Without clear understanding of the units used for ecosystem service(ES)mapping,ES assessment accuracy and the practical application of ES knowledge will be hampered.Method:We systematically reviewed 106 studies over the past 11 years to explore the type,characteristic pattern and deficiencies of mapping units.Result:We proposed that ES mapping units can be categorized into minimal unit for assessing ESs using corresponding indicators and methods,and aggregated unit for analysis and application based on research objectives,and classified the mapping units into five common types.Of the 12 characterizing variables of ES mapping studies,some have been shown to introduce a difference in the selection of mapping units and to exhibit characteristic patterns.We also found that the accuracy of ES assessments based on minimal units was lacking,and aggregated units were insufficient to establish a link between ES knowledge and practice.Conclusion:Herein,we propose possible solutions such as the use of fine spatial resolution grids and the introduction of additional data beyond land cover as supplements to improve the assessment accuracy.To enhance the availability of the results for practice,aggregated units connected with urban planning units should be established at a spatial level suitable for urban management.
文摘In this research,we analyzed the delivery service areas of restaurants,customer satisfaction,and restaurant sales of urban restaurants during the COVID-19 pandemic.We obtained the datasets on food ordering options and restaurant rankings based on Google Maps,Open Street Map,and widely known online food order applications in Iran.Based on this analysis we further modeled suitable areas for future extension of restaurants.We analyzed the online food order data of restaurants’sales and food delivery reports for 1050 restaurants in the city of Tabriz.We collected and analyzed data on the restaurant locations,the number of food orders for each restaurant,and the number of customers and their locations.Our results revealed that the spatial dimension of the newly emerging food delivery areas is of utmost importance for the success of restaurants.This indicates that an optimal location is not longer only dependent on factors like population density and competitors in the direct vicinity but on the services density even from more distant competitors.The results indicate that an optimized spatial distribution of the restaurants together with efficient quality in services can contribute to optimistic urban development.
基金supported by National Basic Research Program of China(973 Program,NO.2009CB723906)the Knowledge Innovation Program of Chinese Academy of Sciences(NO.KKCX1-YW-01).
文摘Digital Earth is an information expression of the real Earth,and is a new way of understanding the Earth in the twenty-first century.This paper introduces a Digital Earth Prototype System(DEPS)developed at the Chinese Academy of Sciences(CAS)and supported by the Knowledge Innovation Program of the Chinese Academy of Sciences.Discussions are made to the theoretical model and technical framework of the Digital Earth,and its related key technologies on spatial information processing,spatial data warehouse technology,virtual reality technology,high-performance and parallel computing.The DEPS consists of seven sub-systems including the spatial data,metadata,model database,Grid geoscience computing,spatial information database,maps service and virtual reality.Meanwhile,we developed a series of application systems such as the environment monitoring for the Olympic Games 2008 in Beijing,natural disasters evaluation,digital city,digital archeology,Asia regional aerosol and climate change.The DEPS/CAS displayed the application ability and potential of the Digital Earth in three levels:the global,national and regional.
基金supported by National Natural Science Foundation of China[No.41971349,No.41930107,No.42090010 and No.41501434]National Key Research and Development Program of China[No.2017YFB0503704 and No.2018YFC0809806].
文摘Without explicit description of map application themes,it is difficult for users to discover desired map resources from massive online Web Map Services(WMS).However,metadata-based map application theme extraction is a challenging multi-label text classification task due to limited training samples,mixed vocabularies,variable length and content arbitrariness of text fields.In this paper,we propose a novel multi-label text classification method,Text GCN-SW-KNN,based on geographic semantics and collaborative training to improve classifica-tion accuracy.The semi-supervised collaborative training adopts two base models,i.e.a modified Text Graph Convolutional Network(Text GCN)by utilizing Semantic Web,named Text GCN-SW,and widely-used Multi-Label K-Nearest Neighbor(ML-KNN).Text GCN-SW is improved from Text GCN by adjusting the adjacency matrix of the heterogeneous word document graph with the shortest semantic distances between themes and words in metadata text.The distances are calculated with the Semantic Web of Earth and Environmental Terminology(SWEET)and WordNet dictionaries.Experiments on both the WMS and layer metadata show that the proposed methods can achieve higher F1-score and accuracy than state-of-the-art baselines,and demonstrate better stability in repeating experiments and robustness to less training data.Text GCN-SW-KNN can be extended to other multi-label text classification scenario for better supporting metadata enhancement and geospatial resource discovery in Earth Science domain.
文摘The volume of publically available geospatial data on the web is rapidly increasing due to advances in server-based technologies and the ease at which data can now be created.However,challenges remain with connecting individuals searching for geospatial data with servers and websites where such data exist.The objective of this paper is to present a publically available Geospatial Search Engine(GSE)that utilizes a web crawler built on top of the Google search engine in order to search the web for geospatial data.The crawler seeding mechanism combines search terms entered by users with predefined keywords that identify geospatial data services.A procedure runs daily to update map server layers and metadata,and to eliminate servers that go offline.The GSE supports Web Map Services,ArcGIS services,and websites that have geospatial data for download.We applied the GSE to search for all available geospatial services under these formats and provide search results including the spatial distribution of all obtained services.While enhancements to our GSE and to web crawler technology in general lie ahead,our work represents an important step toward realizing the potential of a publically accessible tool for discovering the global availability of geospatial data.