Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedfl...Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedflow felds,Array for Real-timeGeostrophic Oceanography(Argo)float observations can be considered benchmarks.In this study,a novel method for comparing Argo profiles with 3-dimensional trajectories obtained by simulating Argo floats in Hybrid Coordinate Ocean Model(HYCOM)-provided flow fields was proposed.Surface and subsurface trajectories were calculated,and their spatial matching characteristics were analyzed.The results demonstrated that(1)the HYCOM surface and subsurface flow felds generally conform to the basic characteristics and trends of ocean currents;(2)the HYCOM sea surface current field error pattern exhibits a symmetrical distribution centered on the equator in the Northern and Southern Hemispheres and increases with increasing latitude;and(3)the HYCOM subsurface flow field exhibits regional differences,with the largest differences in the Gulf Stream,North Atlantic Warm Current,and Westerly Wind Drift region.Through analysis of the disparities between HYCOM and Argo data,the effectiveness of using model simulation data can be enhanced,and the accuracy and dependability of ocean models can be improved.展开更多
Most of the existing virtual scenarios built for the digital protection of Chinese classical private gardens are too modern in expression style to show the aesthetic significance of their historical period.Considering...Most of the existing virtual scenarios built for the digital protection of Chinese classical private gardens are too modern in expression style to show the aesthetic significance of their historical period.Considering the aesthetic commonality between traditional Chinese landscape paintings and classical private gardens and referring to image style transfer,here,a deep neural network was proposed to transfer the aesthetic style from landscape paintings to the virtual scenario of classical private gardens.The network consisted of two parts:style prediction and style transfer.The style prediction network was used to obtain style representation from style paintings,and the style transfer network was used to transfer style representation to the content scenario.The pre-trained network was then embedded into the scenario rendering pipeline and combined with the screen post-processing method to realise the stylised expression of the virtual scenario.To verify the feasibility of this methodology,a virtual scenario of the Humble Administrator’s Garden was used as the content scenario andfive garden landscape paintings from different time periods and painting styles were selected for the case study.The results demonstrated that this methodology could effectively achieve the aesthetic style transfer of a virtual scenario.展开更多
It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE developm...It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE development,and they require further exploration.Based on the comprehensive consideration of the characteristics of VGEs,geographic scene is proposed to organize geographic information and data.We empirically find that geographic scene provides a suitable organization schema to support geo-visualization,geo-simulation,and geo-collaboration.To systematically investigate the concept and method of geographic scene,Geographic Scenario is proposed as the theory on developing geographic scene,and corresponding key issues of the Geographic Scenario are illustrated in this article.Prospects of the proposed method are discussed with the hope of informing future studies of VGEs.展开更多
The international community has made significant efforts to flatten the COVID-19 curve,including predicting transmission[1,2],executing unprecedented global lockdowns and social distancing[3,4],promoting the wearing o...The international community has made significant efforts to flatten the COVID-19 curve,including predicting transmission[1,2],executing unprecedented global lockdowns and social distancing[3,4],promoting the wearing of facemasks and social distancing measures[5],and isolating confirmed cases and contacts[6].Because of the adverse consequences of these lockdown measures[7],many cities have reopened so they can rebuild their economies.However,as mobility has gradually returned towards normal,imported cases from unknown sources have disrupted the recovery situation,and cities are continually at high risk of new waves of infection[8,9]since airborne transmission is the dominant transmission route[10].展开更多
Harmonic analysis of satellite altimetry data based on a global regular grid is affected by the grid spatial tessellation and placement of the grids.With the increase of latitude,the traditional lat/lon grid deforms g...Harmonic analysis of satellite altimetry data based on a global regular grid is affected by the grid spatial tessellation and placement of the grids.With the increase of latitude,the traditional lat/lon grid deforms greatly,resulting in uneven distribution of satellite altimeter data with latitude,which affects the extraction of tidal information.Alternatively,Hexagonal grids have been proved to be advantageous due to their isotropic,uniform neighbourhood,equal-area and more.Considering the merits above,the purpose of this paper is to use the global equal-area hexagonal grid to conduct a harmonic analysis of satellite altimeter data.First,the Icosahedron Snyder Equal Area projection method is used to construct a global equal-area hexagonal grid,Then the time series data of 19.8 years of Jason series satellite altimeter data are obtained.Finally,the harmonic constants of eight constituents(the M2,S2,N2,K2,K1,O1,P1,Q1)are extracted by harmonic analysis.By analysing the results,we conclude that the harmonic constants extracted from the global equal-area hexagonal grid have considerable accuracy and are consistent with the tidal characteristics of the eight components.Meanwhile,the accuracy of harmonic constants extracted from equal-area hexagonal grids is better than that of lat/lon grids.展开更多
Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,...Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,these models are still difficult to invoke for geographical simulations in open web environments.This study designs and develops a framework to assemble service-oriented models from volunteers distributed worldwide for geographical simulations on the web.The framework consists of three layers(task layer,data exchange layer,and model execution layer)that establish a network of serviceoriented locally shared models and simulation tasks for user configurations.With the help of such a framework,users can configure simulation tasks and invoke suitable models shared worldwide for geographical simulations.This article provides an application of the distributed simulation of gross primary production(GPP)by the Biome-BioGeochemical Cycles(BGC)model in China.This application shows that the framework can be beneficial for model assembly from volunteers’computers and distributed simulation tasks that are run for geographical and environmental issues,which can be applied to Digital Earth initiatives.展开更多
Geographic simulation models can be used to explore and better understand the geographical environment. Recent advances in geographic and socio-environmental research have led to a dramatic increase in the number of m...Geographic simulation models can be used to explore and better understand the geographical environment. Recent advances in geographic and socio-environmental research have led to a dramatic increase in the number of models used for this purpose. Some model repositories provide opportunities for users to explore and apply models,but few provide a general evaluation method for assessing the applicability and recognition of models. In this study,an academic impact evaluation method for models is proposed. Five indices are designed based on their pertinence. The analytical hierarchy process is used to calculate the index weights,and the academic impacts of models are quantified with the weighted sum method. The time range is controlled to evaluate the life-term and annual academic impacts of the models. Some models that met the evaluation criteria from different domains are then evaluated. The results show that the academic impact of a model can be quantified with the proposed method,and the major research areas that models impact are identified.展开更多
基金supported by National Natural Science Foundation of China[grant nos:41930648,42171406 and 42171465]National Key Research and Development Program of China[grant no:2021YFB3900901].
文摘Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns,which are essential components in digital Earth construction.To evaluate the accuracy of model-simulatedflow felds,Array for Real-timeGeostrophic Oceanography(Argo)float observations can be considered benchmarks.In this study,a novel method for comparing Argo profiles with 3-dimensional trajectories obtained by simulating Argo floats in Hybrid Coordinate Ocean Model(HYCOM)-provided flow fields was proposed.Surface and subsurface trajectories were calculated,and their spatial matching characteristics were analyzed.The results demonstrated that(1)the HYCOM surface and subsurface flow felds generally conform to the basic characteristics and trends of ocean currents;(2)the HYCOM sea surface current field error pattern exhibits a symmetrical distribution centered on the equator in the Northern and Southern Hemispheres and increases with increasing latitude;and(3)the HYCOM subsurface flow field exhibits regional differences,with the largest differences in the Gulf Stream,North Atlantic Warm Current,and Westerly Wind Drift region.Through analysis of the disparities between HYCOM and Argo data,the effectiveness of using model simulation data can be enhanced,and the accuracy and dependability of ocean models can be improved.
基金This work was supported by the Key Project of the National Natural Science Foundation of China(NSFC)under Grant 41930104National Key R&D Program of China under Grant 2021 YFE0112300+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province under Grant KYCX21_1336China Scholarship Council under Grant 202206860019.
文摘Most of the existing virtual scenarios built for the digital protection of Chinese classical private gardens are too modern in expression style to show the aesthetic significance of their historical period.Considering the aesthetic commonality between traditional Chinese landscape paintings and classical private gardens and referring to image style transfer,here,a deep neural network was proposed to transfer the aesthetic style from landscape paintings to the virtual scenario of classical private gardens.The network consisted of two parts:style prediction and style transfer.The style prediction network was used to obtain style representation from style paintings,and the style transfer network was used to transfer style representation to the content scenario.The pre-trained network was then embedded into the scenario rendering pipeline and combined with the screen post-processing method to realise the stylised expression of the virtual scenario.To verify the feasibility of this methodology,a virtual scenario of the Humble Administrator’s Garden was used as the content scenario andfive garden landscape paintings from different time periods and painting styles were selected for the case study.The results demonstrated that this methodology could effectively achieve the aesthetic style transfer of a virtual scenario.
基金supported by the Key Fund of National Natural Science Foundation of China[grant number 41631175]The National Key Research and Development Program of China[grant number 2017YFB0503500]+1 种基金National Natural Science Foundation of China[grant number 41622108]Priority Academic Program Development of Jiangsu Higher Education Institutions[grant number 164320H116]。
文摘It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE development,and they require further exploration.Based on the comprehensive consideration of the characteristics of VGEs,geographic scene is proposed to organize geographic information and data.We empirically find that geographic scene provides a suitable organization schema to support geo-visualization,geo-simulation,and geo-collaboration.To systematically investigate the concept and method of geographic scene,Geographic Scenario is proposed as the theory on developing geographic scene,and corresponding key issues of the Geographic Scenario are illustrated in this article.Prospects of the proposed method are discussed with the hope of informing future studies of VGEs.
基金support from the National Research FoundationPrime Minister’s Office+7 种基金Singapore under its Campus for Research Excellence and Technological Enterprise(CREATE)programmeThe Hong Kong Polytechnic University Strategic Hiring Scheme(P0036221)support from the Key Program of National Natural Science Foundation of China(41930648)supports from the Hong Kong Research Grants Council(15602619,15603920,and C7064-18GF)supports from the Hong Kong Research Grants Council(14605920,14611621,and C4023-20GF)support from the National University of SingaporeMinistry of Education,Tier 1 under WBS R-109-000-270-133Ministry of Natural Resources of the People’s Republic of China(GS(2021)7327)。
文摘The international community has made significant efforts to flatten the COVID-19 curve,including predicting transmission[1,2],executing unprecedented global lockdowns and social distancing[3,4],promoting the wearing of facemasks and social distancing measures[5],and isolating confirmed cases and contacts[6].Because of the adverse consequences of these lockdown measures[7],many cities have reopened so they can rebuild their economies.However,as mobility has gradually returned towards normal,imported cases from unknown sources have disrupted the recovery situation,and cities are continually at high risk of new waves of infection[8,9]since airborne transmission is the dominant transmission route[10].
基金supported by the National Natural Science Foundation of China[42076203].
文摘Harmonic analysis of satellite altimetry data based on a global regular grid is affected by the grid spatial tessellation and placement of the grids.With the increase of latitude,the traditional lat/lon grid deforms greatly,resulting in uneven distribution of satellite altimeter data with latitude,which affects the extraction of tidal information.Alternatively,Hexagonal grids have been proved to be advantageous due to their isotropic,uniform neighbourhood,equal-area and more.Considering the merits above,the purpose of this paper is to use the global equal-area hexagonal grid to conduct a harmonic analysis of satellite altimeter data.First,the Icosahedron Snyder Equal Area projection method is used to construct a global equal-area hexagonal grid,Then the time series data of 19.8 years of Jason series satellite altimeter data are obtained.Finally,the harmonic constants of eight constituents(the M2,S2,N2,K2,K1,O1,P1,Q1)are extracted by harmonic analysis.By analysing the results,we conclude that the harmonic constants extracted from the global equal-area hexagonal grid have considerable accuracy and are consistent with the tidal characteristics of the eight components.Meanwhile,the accuracy of harmonic constants extracted from equal-area hexagonal grids is better than that of lat/lon grids.
基金supported by National Natural Science Foundation of China:[Grant Numbers 41871285,41930648,42071361,42071363,and U1811464].
文摘Geographical simulation is a popular method in geographical and environmental research.Many models developed to address geographic and environmental issues are distributed worldwide.However,due to the lack of portals,these models are still difficult to invoke for geographical simulations in open web environments.This study designs and develops a framework to assemble service-oriented models from volunteers distributed worldwide for geographical simulations on the web.The framework consists of three layers(task layer,data exchange layer,and model execution layer)that establish a network of serviceoriented locally shared models and simulation tasks for user configurations.With the help of such a framework,users can configure simulation tasks and invoke suitable models shared worldwide for geographical simulations.This article provides an application of the distributed simulation of gross primary production(GPP)by the Biome-BioGeochemical Cycles(BGC)model in China.This application shows that the framework can be beneficial for model assembly from volunteers’computers and distributed simulation tasks that are run for geographical and environmental issues,which can be applied to Digital Earth initiatives.
基金supported by National Key Research and Development Program of China(Grant number 2022YFF0711604)the General Project of the NSF of China(Grant number 42071363).
文摘Geographic simulation models can be used to explore and better understand the geographical environment. Recent advances in geographic and socio-environmental research have led to a dramatic increase in the number of models used for this purpose. Some model repositories provide opportunities for users to explore and apply models,but few provide a general evaluation method for assessing the applicability and recognition of models. In this study,an academic impact evaluation method for models is proposed. Five indices are designed based on their pertinence. The analytical hierarchy process is used to calculate the index weights,and the academic impacts of models are quantified with the weighted sum method. The time range is controlled to evaluate the life-term and annual academic impacts of the models. Some models that met the evaluation criteria from different domains are then evaluated. The results show that the academic impact of a model can be quantified with the proposed method,and the major research areas that models impact are identified.
