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
Virtual geographical environments(VGEs)are being used to represent our sense of place through the application of extended-reality or cross-reality(XR)technologies with a focus on technological advancement and immersio...Virtual geographical environments(VGEs)are being used to represent our sense of place through the application of extended-reality or cross-reality(XR)technologies with a focus on technological advancement and immersion.In light of this,we propose that an expanded and interdisciplinary understanding of the concept of immersion is required to facilitate an understanding of spatial data to a broader audience.The potential of focusing on narrative immersion and literary placemaking in VGEs is discussed to evoke a stronger sense of place and a feeling of presence and belonging in users.This paper seeks to highlight the unique affordances and potentialities of XR narrative style GIS digital representations through an interdisciplinary theoretically lead analysis of outputs created by the Building City dashboards project towards the goal of expanding audiences of non-specialist stakeholders in urban planning processes.展开更多
We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The de...We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The description of an IVGE integrates semantic information expressed using conceptual graphs,a standard knowledge representation technique.In addition,we propose an abstraction process that uses geometric,topologic,and semantic characteristics of geographic features to build a hierarchical graph-based structure describing this IVGE.Our IVGE model enables the support of large-scale and complex geographic environment modeling for multiagent geo-simulations in which the agents are situated and with which they interact.展开更多
In this paper,we address two challenging issues underlying spatial simulation using software agents immersed in virtual geographic environments(VGE).First,the way to describe virtual VGE models using accurate spatial ...In this paper,we address two challenging issues underlying spatial simulation using software agents immersed in virtual geographic environments(VGE).First,the way to describe virtual VGE models using accurate spatial decomposition approaches structured using graph theory techniques.Second,the use of graph abstraction techniques to support realistic and advanced navigation and path planning capabilities for software agents considering the VGE’s characteristics.In order to illustrate our contributions to the growing field of spatial simulations,we present and discuss a case study involving an urban VGE model populated with agents who autonomously and differently interact with multiple abstractions of the same physical environment.展开更多
Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture ...Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.展开更多
On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelli...On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.展开更多
This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatica...This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.展开更多
In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into...In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.展开更多
The study attempts to analyze the regional cultural characteristics of Britain under the unique geographical environment by taking the development process and characteristics of British landscape garden as the researc...The study attempts to analyze the regional cultural characteristics of Britain under the unique geographical environment by taking the development process and characteristics of British landscape garden as the research object.British culture is an important carrier of British landscape garden culture,and the impact of the unique culture of“the empire on which the sun never sets”on formation and development,formal characteristics,temperament and connotation of landscape garden is discussed.展开更多
To avoid crowd evacuation simulations depending on 2D environments and real data,we propose a framework for crowd evacuation modeling and simulation by applying deep reinforcement learning(DRL)and 3D physical environm...To avoid crowd evacuation simulations depending on 2D environments and real data,we propose a framework for crowd evacuation modeling and simulation by applying deep reinforcement learning(DRL)and 3D physical environments(3DPEs).In 3DPEs,we construct simulation scenarios from the aspects of geometry,semantics and physics,which include the environment,the agents and their interactions,and provide training samples for DRL.In DRL,we design a double branch feature extraction combined actor and critic network as the DRL policy and value function and use a clipped surrogate objective with polynomial decay to update the policy.With a unified configuration,we conduct evacuation simulations.In scenarios with one exit,we reproduce and verify the bottleneck effect of congested crowds and explore the impact of exit width and agent characteristics(number,mass and height)on evacuation.In scenarios with two exits and a uniform(nonuniform)distribution of agents,we explore the impact of exit characteristics(width and relative position)and agent characteristics(height,initial location and distribution)on agent exit selection and evacuation.Overall,interactive 3DPEs and unified DRL enable agents to adapt to different evacuation scenarios to simulate crowd evacuation and explore the laws of crowd evacuation.展开更多
This paper applied the method of literature survey to study the current situation of regional clothing color in China and foreign countries,and it summarized the relevant theories in this field. The deficiencies and l...This paper applied the method of literature survey to study the current situation of regional clothing color in China and foreign countries,and it summarized the relevant theories in this field. The deficiencies and losses of the research on regional clothing color in the area of current academic circles were pointed and the development trend of regional color culture in the future clothing design was proposed. The study showed that the research on the regional clothing color has a great theoretical and application significance,and it fits for the present idea of traditional heritage and regional culture dissemination.展开更多
An M 8.1 earthquake that occurred west of the Kunlun Mountains Pass has caused more than 20 collapse bodies or zones, which are mainly distributed near the surface seismic rupture zone, west of Hoh Sai Lake. The colla...An M 8.1 earthquake that occurred west of the Kunlun Mountains Pass has caused more than 20 collapse bodies or zones, which are mainly distributed near the surface seismic rupture zone, west of Hoh Sai Lake. The collapses are of four types, bedrock, soil mass and ice mass collapses and avalanches. The spatial distribution and the characteristics of development of the collapses are analyzed in the paper. Comparised with those caused by other earthquakes, the collapses are smaller in scale. In addition to the lithological characteristics of the crustal media, topographic, geomorphic and climatic factors, weaker seismic ground motion is an important cause for formation of the smaller-scale collapses. The long surface rupture zone and weaker ground motion are important features of the seismic rupture, which may be related to the structure of the preexisting fault.展开更多
Dynamic flood disaster simulation is an emerging and promising technology significantly useful in urban planning,risk assessment,and integrated decision support systems.It is still an important issue to integrate the ...Dynamic flood disaster simulation is an emerging and promising technology significantly useful in urban planning,risk assessment,and integrated decision support systems.It is still an important issue to integrate the large assets such as dynamic observational data,numerical flood simulation models,geographic information technologies,and computing resources into a unified framework.For the intended end user,it is also a holistic solution to create computer interpretable representations and gain insightful understanding of the dynamic disaster processes,the complex impacts,and interactions of disaster factors.In particular,it is still difficult to access and join harmonized data,processing algorithms,and models that are provided by different environmental information infrastructures.In this paper,we demonstrate a virtual geographic environments-based integrated environmental simulation framework for flood disaster management based on the notion of interlinked resources,which is capable of automated accumulating and manipulating of sensor data,creating dynamic geo-analysis and three-dimensional visualizations of ongoing geo-process,and updating the contents of simulation models representing the real environment.The prototype system is evaluated by applying it as a proof of concept to integrate in situ weather observations,numerical weather and flood disaster simulation models,visualization,and analysis of the real time flood event.Case applications indicate that the developed framework can be adopted for use by decision-makers for short-term planning and control since the resulting simulation and visualization are completely based on the latest status of environment.展开更多
Food is essential for human survival, but harmful, toxic substances in food damage and threaten human health. Food production is inseparable from the place where the food is produced; that is, from the geographical en...Food is essential for human survival, but harmful, toxic substances in food damage and threaten human health. Food production is inseparable from the place where the food is produced; that is, from the geographical environment that consists of natural and human environments, two parts of a unified whole. China’s territory is vast and its geographical environment is complex and diverse. Food production patterns in different parts of the country vary significantly, as do local socio-economic and cultural conditions. Such differences have an enormous impact on food safety. Based on the geographical area where food is produced in China, this paper reveals the main environmental problems arising from industrial and agricultural production activities, and related risks for food safety and health. In concluding, we make some recommendations for countermeasures. The main food safety related environmental problems include the excessive application of chemical fertilizers and pesticides; high background levels of heavy metals; discharge of wastewater and heavy metals; and excessive use of additives and antibiotics in livestock and poultry breeding and aquatic products. All these issues can lead to huge risks for food safety and thus health. These are not simply scientific issues, but also political, economic and legal issues, as well as social problems that differ from region to region. Therefore, comprehensive studies are needed to identify risks to food safety and health hazards in different areas. Systematic and comprehensive risk assessments of health problems caused by changing ecosystems, environmental pollution, nutrition problems and lifestyle, and especially comprehensive risk assessments of regional environmental changes and health risks are needed. Measures based on an understanding of local conditions must be put forward to protect food safety and health, to strengthen multi-sectoral management, and to improve environmental quality展开更多
It is of great significance for disaster prevention and mitigation to carry out disaster simulations for dam failure accidents in advance,but at present,there are few professional systems for disaster simulations of t...It is of great significance for disaster prevention and mitigation to carry out disaster simulations for dam failure accidents in advance,but at present,there are few professional systems for disaster simulations of tailings dams.In this paper,we focused on the construction of a virtual geographic environment(VGE)system that provides an effective tool for visualizing the dam-break process of a tailings pond.The dam-break numerical model of the tailings dam based on computational fluid dynamics(CFD)was integrated into the VGE system.The infrastructure of the VGE was supported by a 3-D geographic information system(GIS)with a user-friendly interface for the initiation,visualization,and analysis of the dynamic process of tailings dam failure.Key technologies,including the integration of numerical models,rendering of large-scale scenes,and optimizations of disaster simulation and visualization,were discussed in detail.In the prototype system,information on the run-out path,travel distance,etc.can be obtained to visually describe the flow motion released by two dam failure cases.The simulation results showed that the VGE can be used for the multidimensional,dynamic and interactive visualization of dam-break disasters,and can also be useful for assessing the risk associated with tailings dams.展开更多
In today's world, where re-examination has been given to cultural globalization, the relationship between architectures and specific regions is one of many specific issues. At this time, the study of architecture fro...In today's world, where re-examination has been given to cultural globalization, the relationship between architectures and specific regions is one of many specific issues. At this time, the study of architecture from the perspective of geography has significant meaning for treasuring regional characteristics and protecting the essence of ethnic culture. The study of geo-architecture includes two aspects: the influence of geographical environment upon architecture and reflexively, architectural responses to geographical environment. In "Geo-Architecture and Landscape in China's Geographic and Historic Context Series"(4 volumes), published by Springer Nature in 2016, the contents of "geo-architecture" has been interpreted from various angles as form, function, semantics and symbol. This book is the first to be entitled "Geo-Architecture", which studies the relationship between geography and architecture from the perspective of geographical environment and historical context in China. The book's research reveals the influences of different geographical scales, such as zone(macro), region(middle) and site(micro) scales, on architecture; it discusses dynamic and systematic thought, including such research elements as "Object-Subject-Time", and it reflects views on pattern and process of cultural landscape. Research on geo-architecture aims to help construct the security pattern of the cultural landscape for the new requirements of a new era, which is used to optimize spacial structure, stimulate heritage conservation and renewal, respect the geographical environment, pay attention to historical culture and sustain emotional memory.展开更多
The Yellow Emperor's Classic of Internal Medicine (黄帝内经素问Huangdi Neijing Suwen), created in the Warring States period (475 to 221 BC) described a phenomenon whereby the eastern, western, northern, southern, ...The Yellow Emperor's Classic of Internal Medicine (黄帝内经素问Huangdi Neijing Suwen), created in the Warring States period (475 to 221 BC) described a phenomenon whereby the eastern, western, northern, southern, and central regions were liable to different diseases. It brought forward the principle of treatment in accordance with local conditions. Lv's Spring and Autumn Annals, Huai Nan Tzu (Huainanzi), and the Regiment of Health (Yangshenglun) in the Qin, Han, Wei, Jin, and Southern and Northern Dynasties all describe regional diseases such as goiter (endemic goiter) and yellowish teeth (dental fluorosis) as being caused by geologic and climatic factors. Zhang (miasma), first mentioned in the Han Dynasty, was considered related to the summer heat and dampness particular to the geographical environment of the south. Zhang was further associated with malaria in the Jin Dynasty. General Treatise on the Etiology and Symptomology of Diseases (Zhubingyuanhou Lun), in the Sui Dynasty, held that as a type of poisonous gas, Zhang was the predisposing cause of malaria, seasonal disease, and barbiers, among other conditions. General Guide (Zhinan Zonglun), in the Southern Song Dynasty, regarded Zhang malaria as a separate disease. Healthy Prescription in the Southern Wuling District (Lingnan Weisheng Fang), in the late Song and early Yuan Dynasties, explicitly put forward the concepts of cold Zhang, hot Zhang, and lockjaw Zhang. Guidelines for Treatment of Zhang Malaria (Zhangnue Zhinan), in the Ming Dynasty, maintained that cold Zhang was equivalent to malaria, while hot Zhang and lockjaw Zhang were equivalent to cold damage, the latter of which can be treated by prescriptions for cold damage. Records on Zhang gas and Zhang disease decreased during the Ming and Qing Dynasties.展开更多
Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex te...Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex terrain.Their variable wind speed and direction and complex terrain boundary conditions make simulating advection processes difficult.Based on incompressibleflow conditions,we designed an adaptive time step algorithm for forward advection for the rapid simulation of aerosol processes.The method is based on thefirst-order forward semi-Lagrangian advection method with unconditional mass conservation.Thefirst-order truncated error coefficient function theory generates an adaptive time step to control the accuracy of forward advection.Smoke aerosol simulation experiments in two small outdoor scenes were designed,and the effects of the traditional backward advection and forwardfixed step methods were compared with the algorithm in this study.The proposed simulation method showed improved accuracy compared with the other two methods in experimental scenarios;moreover,compared with those of the traditional backward method,the computation time was significantly reduced and the conservation of mass was significantly improved.Thus,the proposed method is a fast simulation method for outdoor aerosol numerical prediction.KEY POLICY HIGHLIGHTS.The first-order forward semi-Lagrangian method,which requires no iteration and less computation and offers unconditional conservation,was used..The law of truncation error coefficient of thefirst-order forward method was studied and an adaptive step algorithm was designed..Full-size real aerosol experiments in small-scale complex outdoor scenes were conducted for verification and comparison of simulation effects.展开更多
Flood visualization is an effective and intuitive tool for representing flood information from abstract spatiotemporal data.With the growing demand for flood disaster visualizations and mitigation,augmented flood visu...Flood visualization is an effective and intuitive tool for representing flood information from abstract spatiotemporal data.With the growing demand for flood disaster visualizations and mitigation,augmented flood visualizations that support decision makers’perspectives are needed,which can be enhanced by emerging augmented reality(AR)and 3D printing technologies.This paper proposes an innovative flood AR visualization method based on a 3D-printed terrain model and investigates essential techniques,such as the suitable size calculation of the terrain models,the adaptive processing of flood data,and hybridizing virtual flood and terrain models.A prototype experimental system(PES)based on the proposed method and a comparison experimental system(CES)based on a virtual terrain are developed to conduct comparative experiments,which combine the system performance and questionnaire method to evaluate the efficiency and usability of the proposed method.The statistical results indicate that the method is useful for assisting participants in understanding the flood hazard and providing a more intuitive and realistic visual experience compared with that of the traditional AR flood visualization method.The frame rate is stable at 60 frames per second(FPS),which means that the proposed method is more efficient than the traditional AR flood visualization method.展开更多
This paper presents a reality-virtual fusional campus environment.It is an online 3D platform with some aspects of real information merged together.The whole platform is based on OpenSimulator with detailed geo-models...This paper presents a reality-virtual fusional campus environment.It is an online 3D platform with some aspects of real information merged together.The whole platform is based on OpenSimulator with detailed geo-models to represent the university campus.Some preliminary experiments were done to integrate the realistic information with the virtual campus for making the geo-environment not only with detailed indoor and outdoor models,but also with the real representations of the physical world.The overall motivation is to provide a framework with strong support for reality-virtuality fusional modeling in a collaborative 3D online platform for research purposes.展开更多
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supported by the National Science Centre Poland[grant number 2019/33/B/HS4/00057].
文摘Virtual geographical environments(VGEs)are being used to represent our sense of place through the application of extended-reality or cross-reality(XR)technologies with a focus on technological advancement and immersion.In light of this,we propose that an expanded and interdisciplinary understanding of the concept of immersion is required to facilitate an understanding of spatial data to a broader audience.The potential of focusing on narrative immersion and literary placemaking in VGEs is discussed to evoke a stronger sense of place and a feeling of presence and belonging in users.This paper seeks to highlight the unique affordances and potentialities of XR narrative style GIS digital representations through an interdisciplinary theoretically lead analysis of outputs created by the Building City dashboards project towards the goal of expanding audiences of non-specialist stakeholders in urban planning processes.
基金The author thanks Dr Bernard Moulin,Laval University,Dr Phil Graniero,University of Windsor,and Dr Normand Bergeron,Institute for their advice during this research.Supported by the Canadian Network of Centers of Excellence in Geomatics(GEOIDE)the Natural Sciences and Engineering Research Council(NSERC)of Canadaand the Fonds Québécois de la Recherche sur la Nature et les Technologies(FQRNT).
文摘We propose a novel method for the automated generation of virtual geographic environments that allows using geographic information system data to build what we call informed virtual geographic environment(IVGE).The description of an IVGE integrates semantic information expressed using conceptual graphs,a standard knowledge representation technique.In addition,we propose an abstraction process that uses geometric,topologic,and semantic characteristics of geographic features to build a hierarchical graph-based structure describing this IVGE.Our IVGE model enables the support of large-scale and complex geographic environment modeling for multiagent geo-simulations in which the agents are situated and with which they interact.
文摘In this paper,we address two challenging issues underlying spatial simulation using software agents immersed in virtual geographic environments(VGE).First,the way to describe virtual VGE models using accurate spatial decomposition approaches structured using graph theory techniques.Second,the use of graph abstraction techniques to support realistic and advanced navigation and path planning capabilities for software agents considering the VGE’s characteristics.In order to illustrate our contributions to the growing field of spatial simulations,we present and discuss a case study involving an urban VGE model populated with agents who autonomously and differently interact with multiple abstractions of the same physical environment.
基金Funded by the National Natural Science Foundation of China (No.40341011) and the National 863 Program of China(No.2002AA135230)
文摘Integrating the theory of distributed virtual geographic environment (DVGE) and high level architecture(HLA), the architecture of DVGE based on HLA is designed. The data flow and the object models of the architecture are also discussed. The architecture basically meets the need of DVGE in real-time communication, distribution, collaboration, reusing and interoperation, expansion, and standard.
文摘On the basis of previous work, this paper designs an intelligent agent based on virtual geographic environment (VGE) system that is characterized by huge data, rapid computation, multi\|user, multi\|thread and intelligence and issues challenges to traditional GIS models and algorithms. The new advances in software and hardware technology lay a reliable basis for system design, development and application.
文摘This paper demonstrates an experiment on the generation of 3D virtual geographic environment on the basis of experimental flight laser scanning data by a set of algorithms and methods that were developed to automatically interpret range images for extracting geo-spatial features and then to reconstruct geo-objects. The algorithms and methods for the interpretation and modeling of laser scanner data include triangulated-irregular-network (TIN)-based range image interpolation; mathematical-morphology (MM)-based range image filtering, feature extraction and range image segmentation, feature generalization and optimization, 3D objects reconstruction and modeling; computer-graphics (CG)-based visualization and animation of geographic virtual reality environment.
基金supported by the Natural Science Foundation of China under projects 40730530 and 41076115the National Basic Research Program of China under project 2009CB723903the National High-Tech Research and Development Program of China under project 2008AA121701
文摘In this article,the progress of marine geographic information system(MGIS) in China during 2006?2010 is reviewed with emphases on generic MGIS,advanced MGIS and MGIS-based applications.Generic MGIS can be divided into two categories:data-oriented MGIS and user-oriented MGIS,recent achievements of which by Chinese researchers are summarized respectively.Advanced MGIS mainly involves the establishment of 3D virtual marine environment and 'Digital Ocean'.An overview of the 3D MGIS based simulations in the context of ocean phenomena,ocean engineering and ocean battlefield is also presented.Several sug-gestions for future development of MGIS in China are proposed,and trends of development are addressed.
文摘The study attempts to analyze the regional cultural characteristics of Britain under the unique geographical environment by taking the development process and characteristics of British landscape garden as the research object.British culture is an important carrier of British landscape garden culture,and the impact of the unique culture of“the empire on which the sun never sets”on formation and development,formal characteristics,temperament and connotation of landscape garden is discussed.
基金supported and funded by the National Key Technology R&D Program of China[grant number 2020YFC0833103]the Pilot Fund of Frontier Science and Disruptive Technology of Aerospace Information Research Institute,Chinese Academy of Sciences[grant number E0Z211010F]the National Natural Science Foundation of China[grant number 41971361 and the National Natural Science Foundation of China[grant number 42171113].
文摘To avoid crowd evacuation simulations depending on 2D environments and real data,we propose a framework for crowd evacuation modeling and simulation by applying deep reinforcement learning(DRL)and 3D physical environments(3DPEs).In 3DPEs,we construct simulation scenarios from the aspects of geometry,semantics and physics,which include the environment,the agents and their interactions,and provide training samples for DRL.In DRL,we design a double branch feature extraction combined actor and critic network as the DRL policy and value function and use a clipped surrogate objective with polynomial decay to update the policy.With a unified configuration,we conduct evacuation simulations.In scenarios with one exit,we reproduce and verify the bottleneck effect of congested crowds and explore the impact of exit width and agent characteristics(number,mass and height)on evacuation.In scenarios with two exits and a uniform(nonuniform)distribution of agents,we explore the impact of exit characteristics(width and relative position)and agent characteristics(height,initial location and distribution)on agent exit selection and evacuation.Overall,interactive 3DPEs and unified DRL enable agents to adapt to different evacuation scenarios to simulate crowd evacuation and explore the laws of crowd evacuation.
基金Supported by Project of National Social Science Foundation(12BMZ049)Social Science Foundation of Jiangnan University(Z2014103000315)
文摘This paper applied the method of literature survey to study the current situation of regional clothing color in China and foreign countries,and it summarized the relevant theories in this field. The deficiencies and losses of the research on regional clothing color in the area of current academic circles were pointed and the development trend of regional color culture in the future clothing design was proposed. The study showed that the research on the regional clothing color has a great theoretical and application significance,and it fits for the present idea of traditional heritage and regional culture dissemination.
基金TheresearchwassupportedunderakeyScienceandTechnologyResearchProjectoftheScienceandTechnologyDepartmentofQinghaiProvince (2 0 0 2 N 14 1),China
文摘An M 8.1 earthquake that occurred west of the Kunlun Mountains Pass has caused more than 20 collapse bodies or zones, which are mainly distributed near the surface seismic rupture zone, west of Hoh Sai Lake. The collapses are of four types, bedrock, soil mass and ice mass collapses and avalanches. The spatial distribution and the characteristics of development of the collapses are analyzed in the paper. Comparised with those caused by other earthquakes, the collapses are smaller in scale. In addition to the lithological characteristics of the crustal media, topographic, geomorphic and climatic factors, weaker seismic ground motion is an important cause for formation of the smaller-scale collapses. The long surface rupture zone and weaker ground motion are important features of the seismic rupture, which may be related to the structure of the preexisting fault.
基金This study is supported by the National High Technology Research and Development Program of China(863 Program)(Nos.2012AA121305 and 2013AA120701)the National Natural Science Foundation of China(Nos.41471320 and 41201440).
文摘Dynamic flood disaster simulation is an emerging and promising technology significantly useful in urban planning,risk assessment,and integrated decision support systems.It is still an important issue to integrate the large assets such as dynamic observational data,numerical flood simulation models,geographic information technologies,and computing resources into a unified framework.For the intended end user,it is also a holistic solution to create computer interpretable representations and gain insightful understanding of the dynamic disaster processes,the complex impacts,and interactions of disaster factors.In particular,it is still difficult to access and join harmonized data,processing algorithms,and models that are provided by different environmental information infrastructures.In this paper,we demonstrate a virtual geographic environments-based integrated environmental simulation framework for flood disaster management based on the notion of interlinked resources,which is capable of automated accumulating and manipulating of sensor data,creating dynamic geo-analysis and three-dimensional visualizations of ongoing geo-process,and updating the contents of simulation models representing the real environment.The prototype system is evaluated by applying it as a proof of concept to integrate in situ weather observations,numerical weather and flood disaster simulation models,visualization,and analysis of the real time flood event.Case applications indicate that the developed framework can be adopted for use by decision-makers for short-term planning and control since the resulting simulation and visualization are completely based on the latest status of environment.
基金FORHEAD with funding from the Rockefeller Brothers Fund(RBF)
文摘Food is essential for human survival, but harmful, toxic substances in food damage and threaten human health. Food production is inseparable from the place where the food is produced; that is, from the geographical environment that consists of natural and human environments, two parts of a unified whole. China’s territory is vast and its geographical environment is complex and diverse. Food production patterns in different parts of the country vary significantly, as do local socio-economic and cultural conditions. Such differences have an enormous impact on food safety. Based on the geographical area where food is produced in China, this paper reveals the main environmental problems arising from industrial and agricultural production activities, and related risks for food safety and health. In concluding, we make some recommendations for countermeasures. The main food safety related environmental problems include the excessive application of chemical fertilizers and pesticides; high background levels of heavy metals; discharge of wastewater and heavy metals; and excessive use of additives and antibiotics in livestock and poultry breeding and aquatic products. All these issues can lead to huge risks for food safety and thus health. These are not simply scientific issues, but also political, economic and legal issues, as well as social problems that differ from region to region. Therefore, comprehensive studies are needed to identify risks to food safety and health hazards in different areas. Systematic and comprehensive risk assessments of health problems caused by changing ecosystems, environmental pollution, nutrition problems and lifestyle, and especially comprehensive risk assessments of regional environmental changes and health risks are needed. Measures based on an understanding of local conditions must be put forward to protect food safety and health, to strengthen multi-sectoral management, and to improve environmental quality
基金supported by National Key Research and Development Program of China[grant number 2017YFB0504203].
文摘It is of great significance for disaster prevention and mitigation to carry out disaster simulations for dam failure accidents in advance,but at present,there are few professional systems for disaster simulations of tailings dams.In this paper,we focused on the construction of a virtual geographic environment(VGE)system that provides an effective tool for visualizing the dam-break process of a tailings pond.The dam-break numerical model of the tailings dam based on computational fluid dynamics(CFD)was integrated into the VGE system.The infrastructure of the VGE was supported by a 3-D geographic information system(GIS)with a user-friendly interface for the initiation,visualization,and analysis of the dynamic process of tailings dam failure.Key technologies,including the integration of numerical models,rendering of large-scale scenes,and optimizations of disaster simulation and visualization,were discussed in detail.In the prototype system,information on the run-out path,travel distance,etc.can be obtained to visually describe the flow motion released by two dam failure cases.The simulation results showed that the VGE can be used for the multidimensional,dynamic and interactive visualization of dam-break disasters,and can also be useful for assessing the risk associated with tailings dams.
基金Joint Sino-German Research Project supported by the Sino-German Center(NSFC and DFG),No.GZ1201
文摘In today's world, where re-examination has been given to cultural globalization, the relationship between architectures and specific regions is one of many specific issues. At this time, the study of architecture from the perspective of geography has significant meaning for treasuring regional characteristics and protecting the essence of ethnic culture. The study of geo-architecture includes two aspects: the influence of geographical environment upon architecture and reflexively, architectural responses to geographical environment. In "Geo-Architecture and Landscape in China's Geographic and Historic Context Series"(4 volumes), published by Springer Nature in 2016, the contents of "geo-architecture" has been interpreted from various angles as form, function, semantics and symbol. This book is the first to be entitled "Geo-Architecture", which studies the relationship between geography and architecture from the perspective of geographical environment and historical context in China. The book's research reveals the influences of different geographical scales, such as zone(macro), region(middle) and site(micro) scales, on architecture; it discusses dynamic and systematic thought, including such research elements as "Object-Subject-Time", and it reflects views on pattern and process of cultural landscape. Research on geo-architecture aims to help construct the security pattern of the cultural landscape for the new requirements of a new era, which is used to optimize spacial structure, stimulate heritage conservation and renewal, respect the geographical environment, pay attention to historical culture and sustain emotional memory.
文摘The Yellow Emperor's Classic of Internal Medicine (黄帝内经素问Huangdi Neijing Suwen), created in the Warring States period (475 to 221 BC) described a phenomenon whereby the eastern, western, northern, southern, and central regions were liable to different diseases. It brought forward the principle of treatment in accordance with local conditions. Lv's Spring and Autumn Annals, Huai Nan Tzu (Huainanzi), and the Regiment of Health (Yangshenglun) in the Qin, Han, Wei, Jin, and Southern and Northern Dynasties all describe regional diseases such as goiter (endemic goiter) and yellowish teeth (dental fluorosis) as being caused by geologic and climatic factors. Zhang (miasma), first mentioned in the Han Dynasty, was considered related to the summer heat and dampness particular to the geographical environment of the south. Zhang was further associated with malaria in the Jin Dynasty. General Treatise on the Etiology and Symptomology of Diseases (Zhubingyuanhou Lun), in the Sui Dynasty, held that as a type of poisonous gas, Zhang was the predisposing cause of malaria, seasonal disease, and barbiers, among other conditions. General Guide (Zhinan Zonglun), in the Southern Song Dynasty, regarded Zhang malaria as a separate disease. Healthy Prescription in the Southern Wuling District (Lingnan Weisheng Fang), in the late Song and early Yuan Dynasties, explicitly put forward the concepts of cold Zhang, hot Zhang, and lockjaw Zhang. Guidelines for Treatment of Zhang Malaria (Zhangnue Zhinan), in the Ming Dynasty, maintained that cold Zhang was equivalent to malaria, while hot Zhang and lockjaw Zhang were equivalent to cold damage, the latter of which can be treated by prescriptions for cold damage. Records on Zhang gas and Zhang disease decreased during the Ming and Qing Dynasties.
基金supported by National Key Research and Development Program of China [grant numbers 2020YFF0400405].
文摘Outdoor aerosol processes are often associated with disasters and diseases,which threaten human life and health.Outdoor aerosols are afluid system affected by meteorological conditions and three-dimensional complex terrain.Their variable wind speed and direction and complex terrain boundary conditions make simulating advection processes difficult.Based on incompressibleflow conditions,we designed an adaptive time step algorithm for forward advection for the rapid simulation of aerosol processes.The method is based on thefirst-order forward semi-Lagrangian advection method with unconditional mass conservation.Thefirst-order truncated error coefficient function theory generates an adaptive time step to control the accuracy of forward advection.Smoke aerosol simulation experiments in two small outdoor scenes were designed,and the effects of the traditional backward advection and forwardfixed step methods were compared with the algorithm in this study.The proposed simulation method showed improved accuracy compared with the other two methods in experimental scenarios;moreover,compared with those of the traditional backward method,the computation time was significantly reduced and the conservation of mass was significantly improved.Thus,the proposed method is a fast simulation method for outdoor aerosol numerical prediction.KEY POLICY HIGHLIGHTS.The first-order forward semi-Lagrangian method,which requires no iteration and less computation and offers unconditional conservation,was used..The law of truncation error coefficient of thefirst-order forward method was studied and an adaptive step algorithm was designed..Full-size real aerosol experiments in small-scale complex outdoor scenes were conducted for verification and comparison of simulation effects.
基金the National Key R&D Plan of China[grant number 2017YFC1500906]the National Natural Science Foundation of China[grant number 41871323,41771442]+1 种基金Pre-research Project of Equipment Development Department[grant number 315050501]the Zhejiang Institute of Advanced Technology Chinese Academy of Sciences Special Fund Collaborative Innovation Project[grant number ZK-CX-2018-04].
文摘Flood visualization is an effective and intuitive tool for representing flood information from abstract spatiotemporal data.With the growing demand for flood disaster visualizations and mitigation,augmented flood visualizations that support decision makers’perspectives are needed,which can be enhanced by emerging augmented reality(AR)and 3D printing technologies.This paper proposes an innovative flood AR visualization method based on a 3D-printed terrain model and investigates essential techniques,such as the suitable size calculation of the terrain models,the adaptive processing of flood data,and hybridizing virtual flood and terrain models.A prototype experimental system(PES)based on the proposed method and a comparison experimental system(CES)based on a virtual terrain are developed to conduct comparative experiments,which combine the system performance and questionnaire method to evaluate the efficiency and usability of the proposed method.The statistical results indicate that the method is useful for assisting participants in understanding the flood hazard and providing a more intuitive and realistic visual experience compared with that of the traditional AR flood visualization method.The frame rate is stable at 60 frames per second(FPS),which means that the proposed method is more efficient than the traditional AR flood visualization method.
基金the Direct Grant of the Chinese University of Hong Kong (No.2021064)the National High Technology Research and Development Program of China (No.2010AA122202)
文摘This paper presents a reality-virtual fusional campus environment.It is an online 3D platform with some aspects of real information merged together.The whole platform is based on OpenSimulator with detailed geo-models to represent the university campus.Some preliminary experiments were done to integrate the realistic information with the virtual campus for making the geo-environment not only with detailed indoor and outdoor models,but also with the real representations of the physical world.The overall motivation is to provide a framework with strong support for reality-virtuality fusional modeling in a collaborative 3D online platform for research purposes.