Even Unzen volcano has been declared to be in a state of relative dormancy,the latest formed lava lobe No.11 now represents a potential slope failure mass based on the latest research.This paper concentrates on the st...Even Unzen volcano has been declared to be in a state of relative dormancy,the latest formed lava lobe No.11 now represents a potential slope failure mass based on the latest research.This paper concentrates on the stability of the lava lobe No.11 and its possible critical sliding mass.It proposes geographic information systems (GIS) based three-dimensional (3D) slope stability analysis models.It uses a 3D locating approach to identify the 3D critical slip surface and to analyze the 3D stability of the lava lobe No.11.At the same time,the new 3D approach shows the effectiveness in selecting the range of the Monte Carlo random variables and locating the critical slip surface in different parts of the lava lobe No.11.The results are very valuable for judging the stability of the lava lobe and assigning the monitoring equipments.展开更多
Research on Arctic passages has mainly focused on navigation policies,sea ice extraction models,and navigation of Arctic sea routes.It is difficult to quantitatively address the specific problems encountered by ships ...Research on Arctic passages has mainly focused on navigation policies,sea ice extraction models,and navigation of Arctic sea routes.It is difficult to quantitatively address the specific problems encountered by ships sailing in the Arctic in real time through traditional manual approaches.Additionally,existing sea ice information service systems focus on data sharing and lack online calculation and analysis capabil-ities,making it difficult for decision-makers to derive valuable informa-tion from massive amounts of data.To improve navigation analysis through intelligent information service,we built an advanced Ship Navigation Information Service System(SNISS)using a 3D geographic information system(GIS)based on big Earth data.The SNISS includes two main features:(1)heuristic algorithms were developed to identify the optimal navigation route of the Arctic Northeast Passage(NEP)from a macroscale perspective for the past 10 years to the next 100 years,and(2)for key sea straits along the NEP,online local seaice images can be retrieved to provide a fully automatic sea ice data processing workflow,solving the problems of poor flexibility and low availability of real sea ice remote sensing data extraction.This work can potentially enhance the safety of shipping navigation along the NEP.展开更多
3D GIS最重要的特征之一就是虚拟现实表现,其本质是可视化技术与GIS数据库的整合,以满足各种应用如生态农业、灾害预测等方面的需求。以GIS数据库的环境数据和气象数据为基础,通过对雨雪的效果模拟,将GIS气象数据以实时的可视化形式逼...3D GIS最重要的特征之一就是虚拟现实表现,其本质是可视化技术与GIS数据库的整合,以满足各种应用如生态农业、灾害预测等方面的需求。以GIS数据库的环境数据和气象数据为基础,通过对雨雪的效果模拟,将GIS气象数据以实时的可视化形式逼真地表现出来。实验方法采用粒子系统,对单个点元赋予利用Photoshop制作的大面积纹理,这样采用的粒子数减少到普通粒子系统的十分之一,渲染速度为普通粒子系统的十倍以上,以较小的系统资源消耗达到了更加实时逼真的效果,对雪的动态堆积和雨水地面效果采用GPU加速3维渲染,原型系统同时能接受用户对实验环境如粒子纹理、雨雪量的设置。提出根据气象数据进行天气模拟的自适应策略,从而更加适应实际应用需要。展开更多
3D terrain visualization of geographic information systems(GIS)data has become an important issue in recent years.This is due to the emergence of new geo-browsers such as Google Earth,widely popular among users.The av...3D terrain visualization of geographic information systems(GIS)data has become an important issue in recent years.This is due to the emergence of new geo-browsers such as Google Earth,widely popular among users.The availability of 3D representation tools has increased the demand for 3D terrain visualization.The aim of this paper is to review the literature related to the 3D terrain visualization of GIS data from the first map produced until the online mapping era.The reviews are divided into four different sections:manual visualization of 3D terrain,automated visualization of 3D terrain,online visualization of 3D terrain,and software for visualizing 3D terrain.Then,the paper compares between the different types of systems developed by various authors based on the capabilities and the limitations of the system.Some of the techniques have their own strengths and limitations which solve the problem in 3D terrain visualization.However,the research on improving 3D terrain visualization is still ongoing.This is due to the popularity of online environments and mobile devices that render 3D terrain.This review paper will help interested users understand the current state of 3D terrain visualization of GIS data in a better way.展开更多
基金Supported by the National Natural Science Foundation of China (40972229)provided by JSPS and Sabo Technical Center,Japan
文摘Even Unzen volcano has been declared to be in a state of relative dormancy,the latest formed lava lobe No.11 now represents a potential slope failure mass based on the latest research.This paper concentrates on the stability of the lava lobe No.11 and its possible critical sliding mass.It proposes geographic information systems (GIS) based three-dimensional (3D) slope stability analysis models.It uses a 3D locating approach to identify the 3D critical slip surface and to analyze the 3D stability of the lava lobe No.11.At the same time,the new 3D approach shows the effectiveness in selecting the range of the Monte Carlo random variables and locating the critical slip surface in different parts of the lava lobe No.11.The results are very valuable for judging the stability of the lava lobe and assigning the monitoring equipments.
文摘针对现有三维G IS系统以及虚拟现实系统存在的问题,基于可动态更新G IS数据开发了具备三维场景漫游、外部数据库查询和部分空间分析功能的虚拟现实系统。该文首先介绍了地理信息系统和虚拟现实的现状及其融合发展的背景,然后描述了在V isual VC++.NET开发环境及OpenGL函数库的基础上,利用Terra V ista、Mu ltiGen C reator及Vega等仿真建模、实时渲染工具建造系统的过程,并以“数字都江堰演示系统”的建设证实了其实用效果。
文摘Research on Arctic passages has mainly focused on navigation policies,sea ice extraction models,and navigation of Arctic sea routes.It is difficult to quantitatively address the specific problems encountered by ships sailing in the Arctic in real time through traditional manual approaches.Additionally,existing sea ice information service systems focus on data sharing and lack online calculation and analysis capabil-ities,making it difficult for decision-makers to derive valuable informa-tion from massive amounts of data.To improve navigation analysis through intelligent information service,we built an advanced Ship Navigation Information Service System(SNISS)using a 3D geographic information system(GIS)based on big Earth data.The SNISS includes two main features:(1)heuristic algorithms were developed to identify the optimal navigation route of the Arctic Northeast Passage(NEP)from a macroscale perspective for the past 10 years to the next 100 years,and(2)for key sea straits along the NEP,online local seaice images can be retrieved to provide a fully automatic sea ice data processing workflow,solving the problems of poor flexibility and low availability of real sea ice remote sensing data extraction.This work can potentially enhance the safety of shipping navigation along the NEP.
文摘3D terrain visualization of geographic information systems(GIS)data has become an important issue in recent years.This is due to the emergence of new geo-browsers such as Google Earth,widely popular among users.The availability of 3D representation tools has increased the demand for 3D terrain visualization.The aim of this paper is to review the literature related to the 3D terrain visualization of GIS data from the first map produced until the online mapping era.The reviews are divided into four different sections:manual visualization of 3D terrain,automated visualization of 3D terrain,online visualization of 3D terrain,and software for visualizing 3D terrain.Then,the paper compares between the different types of systems developed by various authors based on the capabilities and the limitations of the system.Some of the techniques have their own strengths and limitations which solve the problem in 3D terrain visualization.However,the research on improving 3D terrain visualization is still ongoing.This is due to the popularity of online environments and mobile devices that render 3D terrain.This review paper will help interested users understand the current state of 3D terrain visualization of GIS data in a better way.
