A design of low-light-level night vision system is described,which can image objects selectively in the specific space. The system can selectively image some objects in specific distances,meanwhile ignore those shelte...A design of low-light-level night vision system is described,which can image objects selectively in the specific space. The system can selectively image some objects in specific distances,meanwhile ignore those shelters on the way of observation by combining an intensifying charge coupled device(ICCD) with a near infrared laser assisted in vision,whose operation wavelength matches with the photocathode of the image tube,and adopting the gated mode and adjustable time-delay. A semiconductor laser diode of 100 W in peak power is chosen for illumination. The laser and the image tube operate in 150 ns pulse width and 2 kHz repeat frequency. Some images of different objects at the different distances within 100 m can be obtained clearly,and even behind a grove by using a sampling circuit and a delay control device at 100 W in peak power of semiconductor laser diode,150 ns in pulse width of laser and image tube,2 kHz in repeat frequency.展开更多
The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requ...The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requires considering spatial local context and long-term dependencies. To address this problem, the proposed approach is inspired by the MAC-UNet network which is an extension of U-Net, densely connected combined with channel attention. The advantages of this solution are as follows: 4) The new model introduces a new attention called propagate attention to build an attention-based encoder. 2) The fusion of multi-scale information is achieved by a weighted linear combination of the attentions whose coefficients are learned during the training phase. 3) Introducing in the decoder, the Spatial-Channel-Global-Local block which is an attention layer that uniquely combines channel attention and spatial attention locally and globally. The performances of the model are evaluated on 2 datasets WHDLD and DLRSD and show results of mean intersection over union (mIoU) index in progress between 1.54% and 10.47% for DLRSD and between 1.04% and 4.37% for WHDLD compared with the most efficient algorithms with attention mechanisms like MAU-Net and transformers like TMNet.展开更多
【目的】绿化资源配置是城市公共空间优化的重要环节之一,对居民生活质量的提升有着积极的作用。城市街道绿化泛类结构(urban street greening general structure,USGGS)能够反映街道绿化在行人视觉环境中的整体特征,研究USGGS聚类对于...【目的】绿化资源配置是城市公共空间优化的重要环节之一,对居民生活质量的提升有着积极的作用。城市街道绿化泛类结构(urban street greening general structure,USGGS)能够反映街道绿化在行人视觉环境中的整体特征,研究USGGS聚类对于物质空间要素数量以及物质空间形态的改变,能够有效探究街道绿化对行人视觉感知水平的影响。【方法】采用百度街景数据,利用DeepLabV3+神经网络模型,对天津市市内六区街道的物质空间要素进行分割,使用ArcGIS软件对空间分布特征进行可视化处理,结合数理统计分析结果,探讨USGGS与行人视觉感知之间的关系。【结果】USGGS聚类呈现向心聚集型的空间分布特征,城市主干道及快速路的行人视觉感知空间分布特征较为同质化,空间异质化现象集中出现在街道断面狭窄的生活型街道以及商业型街道。不同聚类的USGGS不仅对行人视觉感知有不同程度的影响,也与场所属性以及绿化空间位置密切相关。【结论】提升城市街道环境质量需要考虑行人视觉感知水平。合理的USGGS配置以及适当的种植点位能够更好地适应周围场所的属性,促进城市公共空间与城市街道绿化的有机融合,助推城市更新工作的精细化管理,提升城市人居环境质量。展开更多
文摘A design of low-light-level night vision system is described,which can image objects selectively in the specific space. The system can selectively image some objects in specific distances,meanwhile ignore those shelters on the way of observation by combining an intensifying charge coupled device(ICCD) with a near infrared laser assisted in vision,whose operation wavelength matches with the photocathode of the image tube,and adopting the gated mode and adjustable time-delay. A semiconductor laser diode of 100 W in peak power is chosen for illumination. The laser and the image tube operate in 150 ns pulse width and 2 kHz repeat frequency. Some images of different objects at the different distances within 100 m can be obtained clearly,and even behind a grove by using a sampling circuit and a delay control device at 100 W in peak power of semiconductor laser diode,150 ns in pulse width of laser and image tube,2 kHz in repeat frequency.
文摘The semantic segmentation of very high spatial resolution remote sensing images is difficult due to the complexity of interpreting the interactions between the objects in the scene. Indeed, effective segmentation requires considering spatial local context and long-term dependencies. To address this problem, the proposed approach is inspired by the MAC-UNet network which is an extension of U-Net, densely connected combined with channel attention. The advantages of this solution are as follows: 4) The new model introduces a new attention called propagate attention to build an attention-based encoder. 2) The fusion of multi-scale information is achieved by a weighted linear combination of the attentions whose coefficients are learned during the training phase. 3) Introducing in the decoder, the Spatial-Channel-Global-Local block which is an attention layer that uniquely combines channel attention and spatial attention locally and globally. The performances of the model are evaluated on 2 datasets WHDLD and DLRSD and show results of mean intersection over union (mIoU) index in progress between 1.54% and 10.47% for DLRSD and between 1.04% and 4.37% for WHDLD compared with the most efficient algorithms with attention mechanisms like MAU-Net and transformers like TMNet.
文摘【目的】绿化资源配置是城市公共空间优化的重要环节之一,对居民生活质量的提升有着积极的作用。城市街道绿化泛类结构(urban street greening general structure,USGGS)能够反映街道绿化在行人视觉环境中的整体特征,研究USGGS聚类对于物质空间要素数量以及物质空间形态的改变,能够有效探究街道绿化对行人视觉感知水平的影响。【方法】采用百度街景数据,利用DeepLabV3+神经网络模型,对天津市市内六区街道的物质空间要素进行分割,使用ArcGIS软件对空间分布特征进行可视化处理,结合数理统计分析结果,探讨USGGS与行人视觉感知之间的关系。【结果】USGGS聚类呈现向心聚集型的空间分布特征,城市主干道及快速路的行人视觉感知空间分布特征较为同质化,空间异质化现象集中出现在街道断面狭窄的生活型街道以及商业型街道。不同聚类的USGGS不仅对行人视觉感知有不同程度的影响,也与场所属性以及绿化空间位置密切相关。【结论】提升城市街道环境质量需要考虑行人视觉感知水平。合理的USGGS配置以及适当的种植点位能够更好地适应周围场所的属性,促进城市公共空间与城市街道绿化的有机融合,助推城市更新工作的精细化管理,提升城市人居环境质量。
