The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics ...The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.展开更多
It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this s...It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.展开更多
Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, how...Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.展开更多
A practical method for visualizing flood area and evaluating damage is presented, which consists of two technical approaches: self\|programming and adapting commercial GIS platforms. The low\|cost and easy\|to\|use GI...A practical method for visualizing flood area and evaluating damage is presented, which consists of two technical approaches: self\|programming and adapting commercial GIS platforms. The low\|cost and easy\|to\|use GIS\|Based model developed by self\|programming can meet current requirements of most local authorities, especially in developing countries. In this model, two cases, non\|source flood and source flood, are distinguished and the Seed\|spread algorithm suitable for source\|flood is discussed; The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data. and all thematic maps are converted to raster format before overlay analysis. Two measures are taken to improve the operation efficiency of speed seed\|spread algorithm. The accuracy of the model mainly depends on the resolution and precision of the DEM data, and the accuracy of registering all raster layers and the quality of attribute data.展开更多
目的利用科学知识图谱,对国内外文献进行分析对比,以客观数据和直观图谱分析为依据,对当前城市品牌的热点问题和发展趋势进行分析和总结。方法运用可视化文献分析软件Cite Space 6.2R1,以中国知网数据库中的北大核心、CSSCI、SCI期刊文...目的利用科学知识图谱,对国内外文献进行分析对比,以客观数据和直观图谱分析为依据,对当前城市品牌的热点问题和发展趋势进行分析和总结。方法运用可视化文献分析软件Cite Space 6.2R1,以中国知网数据库中的北大核心、CSSCI、SCI期刊文献和Web of Science核心集合数据库中收录的城市品牌相关文献为数据来源,对国内外城市品牌的发文量、作者及研究机构合作分布、相关研究热点、研究领域发展趋势等方面问题绘制科学知识图谱,并进行可视化分析。结论国外城市品牌发文量呈现出波动上升态势;作者及研究机构合作密切,形成明显合作团队;city、impact、model为研究热点;reputation、engagement、mediating role、perceived value、experiences是较具影响的研究前沿领域;整体研究聚焦于城市品牌与外界因素的相互作用,如何通过品牌的塑造和传播提高城市在公众心中的地位,以及如何增加人们与城市品牌的互动和参与;研究趋势从理论研究到实践应用、从单一视角到多维度、从系统化到参与式研究。国内城市品牌发文量低于国外,整体发文量呈现出波动缓慢上升态势;作者及研究机构合作不密切,没有形成成熟的合作团队;城市品牌、城市营销、城市形象、品牌为研究热点;城市形象、城市发展、品牌形象是较具影响力的研究前沿领域;整体研究侧重于城市品牌本身,如何借助城市品牌推动城市形象的提升;研究趋势由自发到自觉、由个案到普遍、由地方探索到统筹推进。展开更多
机场飞行区现使用的场面监视方法存在着定位偏差较大、不稳定、易跳变、皆为点源定位等问题。针对这些问题,设计了基于视觉图像的飞行区监视方法,实现快速准确的目标检测和轮廓定位,使飞行区监视更加稳定精确。提出了一种基于MobileNetV...机场飞行区现使用的场面监视方法存在着定位偏差较大、不稳定、易跳变、皆为点源定位等问题。针对这些问题,设计了基于视觉图像的飞行区监视方法,实现快速准确的目标检测和轮廓定位,使飞行区监视更加稳定精确。提出了一种基于MobileNetV3和YOLOv5的网络模型(以下称为MobileNetV3-YOLOv5),即在YOLOv5的主干中使用MobileNetV3,来提高对目标的检测速度和准确度;提出了一种基于优化特征点提取的改进定向快速旋转简报(Oriented FAST and Rotated BRIEF,ORB)算法,将图像分割成多个区域,分别提取每个区域的特征点,从而提高目标识别框内区域的特征点识别数量,再进行特征点聚类筛选,最后根据识别目标类型采用最小包围盒进行轮廓划分,得到目标的轮廓定位。试验结果表明:MobileNetV3-YOLOv5方法对比原始YOLOv5模型,在识别目标准确率方面提升5百分点,在效率方面提升14张/s;同时在0~60 m的范围内,轮廓估计误差仅为2.9%;体现了所提出的监视方法的有效性,可以提升飞行区监视定位准确性和运行安全性。展开更多
基金supported by travel grants from Monash University and the University of Sichuan(to YY)Research Grants from the Australian Research Council(No.DP0451206)(to MGPR)National Health and Medical Research Council(No.384115)(to MGPR)。
文摘The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.
文摘It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.
基金National Natural Science Foundation of China (31171082)Natural Science Foundation of Anhui Province (070413138)Key Research Foundation of Anhui Province Education Department (KJ2009A167)
文摘Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.
文摘A practical method for visualizing flood area and evaluating damage is presented, which consists of two technical approaches: self\|programming and adapting commercial GIS platforms. The low\|cost and easy\|to\|use GIS\|Based model developed by self\|programming can meet current requirements of most local authorities, especially in developing countries. In this model, two cases, non\|source flood and source flood, are distinguished and the Seed\|spread algorithm suitable for source\|flood is discussed; The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data. and all thematic maps are converted to raster format before overlay analysis. Two measures are taken to improve the operation efficiency of speed seed\|spread algorithm. The accuracy of the model mainly depends on the resolution and precision of the DEM data, and the accuracy of registering all raster layers and the quality of attribute data.
文摘目的利用科学知识图谱,对国内外文献进行分析对比,以客观数据和直观图谱分析为依据,对当前城市品牌的热点问题和发展趋势进行分析和总结。方法运用可视化文献分析软件Cite Space 6.2R1,以中国知网数据库中的北大核心、CSSCI、SCI期刊文献和Web of Science核心集合数据库中收录的城市品牌相关文献为数据来源,对国内外城市品牌的发文量、作者及研究机构合作分布、相关研究热点、研究领域发展趋势等方面问题绘制科学知识图谱,并进行可视化分析。结论国外城市品牌发文量呈现出波动上升态势;作者及研究机构合作密切,形成明显合作团队;city、impact、model为研究热点;reputation、engagement、mediating role、perceived value、experiences是较具影响的研究前沿领域;整体研究聚焦于城市品牌与外界因素的相互作用,如何通过品牌的塑造和传播提高城市在公众心中的地位,以及如何增加人们与城市品牌的互动和参与;研究趋势从理论研究到实践应用、从单一视角到多维度、从系统化到参与式研究。国内城市品牌发文量低于国外,整体发文量呈现出波动缓慢上升态势;作者及研究机构合作不密切,没有形成成熟的合作团队;城市品牌、城市营销、城市形象、品牌为研究热点;城市形象、城市发展、品牌形象是较具影响力的研究前沿领域;整体研究侧重于城市品牌本身,如何借助城市品牌推动城市形象的提升;研究趋势由自发到自觉、由个案到普遍、由地方探索到统筹推进。
文摘机场飞行区现使用的场面监视方法存在着定位偏差较大、不稳定、易跳变、皆为点源定位等问题。针对这些问题,设计了基于视觉图像的飞行区监视方法,实现快速准确的目标检测和轮廓定位,使飞行区监视更加稳定精确。提出了一种基于MobileNetV3和YOLOv5的网络模型(以下称为MobileNetV3-YOLOv5),即在YOLOv5的主干中使用MobileNetV3,来提高对目标的检测速度和准确度;提出了一种基于优化特征点提取的改进定向快速旋转简报(Oriented FAST and Rotated BRIEF,ORB)算法,将图像分割成多个区域,分别提取每个区域的特征点,从而提高目标识别框内区域的特征点识别数量,再进行特征点聚类筛选,最后根据识别目标类型采用最小包围盒进行轮廓划分,得到目标的轮廓定位。试验结果表明:MobileNetV3-YOLOv5方法对比原始YOLOv5模型,在识别目标准确率方面提升5百分点,在效率方面提升14张/s;同时在0~60 m的范围内,轮廓估计误差仅为2.9%;体现了所提出的监视方法的有效性,可以提升飞行区监视定位准确性和运行安全性。
