为解决Navi-Trainer Professional 5000型全任务大型船舶操纵模拟器无法识别S-57数据格式,致使最新的官方电子海图(ENC)数据文件无法直接应用的问题,采用Scene Editor软件进行海图数据转换,克服船舶操纵模拟器电子海图数据间不融合的问...为解决Navi-Trainer Professional 5000型全任务大型船舶操纵模拟器无法识别S-57数据格式,致使最新的官方电子海图(ENC)数据文件无法直接应用的问题,采用Scene Editor软件进行海图数据转换,克服船舶操纵模拟器电子海图数据间不融合的问题。以天津港附近水域海图文件转换为例,验证Scene Editor软件进行海图数据转换具有可行性,说明基于ENC数据文件的三维实景建模可广泛应用于船舶操纵的教学、科研和培训。展开更多
Cartographic sounding selection is a constraint-based bathymetric generalization process for identifying navigationally relevant soundings for nautical chart display.Electronic Navigational Charts(ENCs)are the premier...Cartographic sounding selection is a constraint-based bathymetric generalization process for identifying navigationally relevant soundings for nautical chart display.Electronic Navigational Charts(ENCs)are the premier maritime navigation medium and are produced according to international standards and distributed around the world.Cartographic generalization for ENCs is a major bottleneck in the chart creation and update process,where high volumes of data collected from constantly changing seafloor topographies require tedious examination.Moreover,these data are provided by multiple sources from various collection platforms at different levels of quality,further complicating the generalization process.Therefore,in this work,a comprehensive sounding selection algorithm is presented that focuses on safe navigation,leveraging both the Digital Surface Model(DSM)of multi-source bathymetry and the cartographic portrayal of the ENC.A taxonomy and hierarchy of soundings found on ENCs are defined and methods to identify these soundings are employed.Furthermore,the significant impact of depth contour generalization on sounding selection distribution is explored.Incorporating additional ENC bathymetric features(rocks,wrecks,and obstructions)affecting sounding distribution,calculating metrics from current chart products,and introducing procedures to correct cartographic constraint violations ensures a shoal-bias and mariner-readable output.This results in a selection that is near navigationally ready and complementary to the specific waterways of the area,contributing to the complete automation of the ENC creation and update process for safer maritime navigation.展开更多
The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land...The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.展开更多
为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:...为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:密码子第三位GC含量为27.55%,ENC范围在35.23~56.67之间,平均值为46.09;RSCU值大于1.00的密码子数目为30个,其中29个第三位碱基以U或A结尾;中性绘图表明GC12与GC3的相关系数为0.143,相关性不显著,回归系数为0.0573;频数分布显示,55%基因的ENC比值集中分布在0~0.1,25%基因的ENC比值分布在0.1~0.2之间;对应分析结果表明,第一向量轴占10.12%的差异,第二向量轴占9.36%的差异,其余两轴分别占7.97%和7.46%,前4轴累计差异为34.91%。中性绘图、ENC-plot和对应性分析均表明普通油茶叶绿体基因密码子偏好受突变作用,更多受选择的影响。最终取高表达优越密码子和高频密码子共有的CUU、AUU、GUU、GUA、UAA、CAA、AAA、GAC、GAA、CCU、ACU、GCU、GCA、UGU、CGU、AGU、UUG、GGU等18个密码子作为最优密码子。该研究结果为利用叶绿体基因工程技术改良普通油茶重要经济性状奠定了基础。展开更多
文摘为解决Navi-Trainer Professional 5000型全任务大型船舶操纵模拟器无法识别S-57数据格式,致使最新的官方电子海图(ENC)数据文件无法直接应用的问题,采用Scene Editor软件进行海图数据转换,克服船舶操纵模拟器电子海图数据间不融合的问题。以天津港附近水域海图文件转换为例,验证Scene Editor软件进行海图数据转换具有可行性,说明基于ENC数据文件的三维实景建模可广泛应用于船舶操纵的教学、科研和培训。
基金supported by the National Oceanic and Atmospheric Administration under[grant number NA20NOS4000196]partially supported by the National Science Foundation under[grant number 1910766].
文摘Cartographic sounding selection is a constraint-based bathymetric generalization process for identifying navigationally relevant soundings for nautical chart display.Electronic Navigational Charts(ENCs)are the premier maritime navigation medium and are produced according to international standards and distributed around the world.Cartographic generalization for ENCs is a major bottleneck in the chart creation and update process,where high volumes of data collected from constantly changing seafloor topographies require tedious examination.Moreover,these data are provided by multiple sources from various collection platforms at different levels of quality,further complicating the generalization process.Therefore,in this work,a comprehensive sounding selection algorithm is presented that focuses on safe navigation,leveraging both the Digital Surface Model(DSM)of multi-source bathymetry and the cartographic portrayal of the ENC.A taxonomy and hierarchy of soundings found on ENCs are defined and methods to identify these soundings are employed.Furthermore,the significant impact of depth contour generalization on sounding selection distribution is explored.Incorporating additional ENC bathymetric features(rocks,wrecks,and obstructions)affecting sounding distribution,calculating metrics from current chart products,and introducing procedures to correct cartographic constraint violations ensures a shoal-bias and mariner-readable output.This results in a selection that is near navigationally ready and complementary to the specific waterways of the area,contributing to the complete automation of the ENC creation and update process for safer maritime navigation.
基金Supported by the Open Bidding Projects of the Office of Land and Resources of the Guangxi Zhuang Autonomous Region(GXZC2015-G3-0575-GTZB)~~
文摘The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.
文摘为了利用叶绿体基因工程技术改良普通油茶的重要经济性状,该研究以普通油茶叶绿体全基因组序列为材料,从中筛选出51条长度大于300 bp且以ATG起始的非重复CDS(Coding DNA Sequence)为对象,利用CodonW软件分析其密码子偏好性。结果表明:密码子第三位GC含量为27.55%,ENC范围在35.23~56.67之间,平均值为46.09;RSCU值大于1.00的密码子数目为30个,其中29个第三位碱基以U或A结尾;中性绘图表明GC12与GC3的相关系数为0.143,相关性不显著,回归系数为0.0573;频数分布显示,55%基因的ENC比值集中分布在0~0.1,25%基因的ENC比值分布在0.1~0.2之间;对应分析结果表明,第一向量轴占10.12%的差异,第二向量轴占9.36%的差异,其余两轴分别占7.97%和7.46%,前4轴累计差异为34.91%。中性绘图、ENC-plot和对应性分析均表明普通油茶叶绿体基因密码子偏好受突变作用,更多受选择的影响。最终取高表达优越密码子和高频密码子共有的CUU、AUU、GUU、GUA、UAA、CAA、AAA、GAC、GAA、CCU、ACU、GCU、GCA、UGU、CGU、AGU、UUG、GGU等18个密码子作为最优密码子。该研究结果为利用叶绿体基因工程技术改良普通油茶重要经济性状奠定了基础。
