Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information in...Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information involving multi-faceted public and public interests, its data security is very important. The use of digital watermarking technology can effectively protect the secu-rity of urban planning basic data. In practical applications, the “screen capture” poses a great threat to the security of remote sensing image. In order to resist the screen capture attacks, the QR code watermark information is encoded and converted, and combined with a circular angle template watermark, a digital watermarking algorithm for remote sensing images in urban planning information management is proposed. And the proposed algorithm is experimentally verified. Experiments show that the algorithm is robust against screen capture attacks, and provide security guarantee for urban construction and management.展开更多
Ecological security is an overall reflection of the ecological integrity and health level of natural semi-natural ecosystems. The study obtained quantitative results of ecological land-use variety by using spatial tra...Ecological security is an overall reflection of the ecological integrity and health level of natural semi-natural ecosystems. The study obtained quantitative results of ecological land-use variety by using spatial transfer matrix, based on status maps of Anqing City in 2005 and 2017. We combined the superposition analysis of ecological sensitivity with ecological disturbance evaluation to judge the strategic nodes and corridors of core protection type, including maintenance promotion type and potential supplementary type in the study area. In addition, we introduced the model of minimum cumulative resistance to construct the ecological security pattern, superimposing with the results of ecological land use. According to the trend of change over the past decade, the study has the great significance to the ecological security pattern so that we can effectively guide to take management strategy for security landscape.展开更多
A supercell of a nanotube formed by a carbon nanotube (CNT) and a silicon nanotube (SiNT) is established. The electronic structure and optical properties are implemented through the first-principles method based on th...A supercell of a nanotube formed by a carbon nanotube (CNT) and a silicon nanotube (SiNT) is established. The electronic structure and optical properties are implemented through the first-principles method based on the density functional theory (DFT) with the generalized gradient approximation (GGA). The calculated results show that (6, 6) - (6, 6) silicon/carbon nanotubes (Si/CNTs) presented a direct band gap of 0.093 eV, (4, 4) - (6, 6) silicon/carbon nanotubes presented a direct band gap of 0.563 eV. The top of valence band was fundamentally determined by the Si-3p states and C-2p states, and the bottom of conduction band was primarily occupied by the C-2p states and Si-3p states in the Si/CNTs. It was found that (6, 6) - (6, 6) Si/CNTs have smaller energy band gap and better conductivity. Besides, Si/CNTs have satisfactory absorption characteristics and luminous efficiency in ultraviolet band.展开更多
Background:Spontaneously resolved primary congenital glaucoma is rare and the mechanism remains unknown.Previous literature described the phenomenon of spontaneous resolution of primary congenital glaucoma,with no fur...Background:Spontaneously resolved primary congenital glaucoma is rare and the mechanism remains unknown.Previous literature described the phenomenon of spontaneous resolution of primary congenital glaucoma,with no further reports on follow-up visits and visual development of patients.We report a case of unilateral spontaneously resolved primary congenital glaucoma at a 7-year follow-up visit and describe the differential development of axial length(AL)between affected eye and healthy eye.Case Description:A 6-year-old boy firstly presented at Zhongshan Ophthalmic Center with expanded corneas and ruptures in Descemet’s membranes(Haab’s striae)and apparently thin retinal nerve fiber layer(RNFL)in the left eye(LE),but normal intraocular pressure(IOP)of both eyes without anti-glaucoma medications or surgeries.At 7-year follow-up,the IOPs of bilateral eyes were stable ranging from 8 to 11 mmHg.A cup to disc ratio and the RNFL was stable in the LE at the following visit.The AL increased almost 3 mm in the right eye(RE)but 1.5 mm in the LE.Without anti-glaucoma medications or surgeries,the primary congenital glaucoma was spontaneously resolved.Conclusions:It may figure out the development and influence of the affected eye of the patient,including AL and refraction state with regular ophthalmic examination at periodic follow-up.展开更多
As a well-known urban landscape concept to describe urban space quality,urban street vitality is a subjective human perception of the urban environment but difficult to evaluate directly from the physical space.The st...As a well-known urban landscape concept to describe urban space quality,urban street vitality is a subjective human perception of the urban environment but difficult to evaluate directly from the physical space.The study utilized a modern machine learning computer vision algorithm in the urban build environment to simulate the process,which starts with the visual perception of the urban street landscape and ends with the human reaction to street vitality.By analyzing the optimized trained model,we tried to identify urban street vitality’s visual features and evaluate their importance.A region around the Mochou Lake in Nanjing,China,was set as our study area.Seven investigators surveyed the area,recorded their evaluation score on each site’s vitality level with a corresponding picture taken on site.A total of 370 pictures and recorded score pairs from 231 valid survey sites were used to train a convolutional neural network.After optimization,a deep neural network model with 43 layers,including 11 convolutional ones,was created.Heat maps were then used to identify the features which lead to high vitality score outputs.The spatial distributions of different types of feature entities were also analyzed to help identify the spatial effects.The study found that visual features,including human,construction site,shop front,and roadside/walking pavement,are vital ones that correspond to the vitality of the urban street.The consistency of these critical features with traditional urban vitality features indicates the model had learned useful knowledge from the training process.Applying the trained model in urban planning practices can help to improve the city environment for better attraction of residents’activities and communications.展开更多
文摘Remote Sensing data, as an essential urban basic information in urban planning, has the characteristics of large information capacity, real time, high update speed and accuracy. Because of urban spatial information involving multi-faceted public and public interests, its data security is very important. The use of digital watermarking technology can effectively protect the secu-rity of urban planning basic data. In practical applications, the “screen capture” poses a great threat to the security of remote sensing image. In order to resist the screen capture attacks, the QR code watermark information is encoded and converted, and combined with a circular angle template watermark, a digital watermarking algorithm for remote sensing images in urban planning information management is proposed. And the proposed algorithm is experimentally verified. Experiments show that the algorithm is robust against screen capture attacks, and provide security guarantee for urban construction and management.
文摘Ecological security is an overall reflection of the ecological integrity and health level of natural semi-natural ecosystems. The study obtained quantitative results of ecological land-use variety by using spatial transfer matrix, based on status maps of Anqing City in 2005 and 2017. We combined the superposition analysis of ecological sensitivity with ecological disturbance evaluation to judge the strategic nodes and corridors of core protection type, including maintenance promotion type and potential supplementary type in the study area. In addition, we introduced the model of minimum cumulative resistance to construct the ecological security pattern, superimposing with the results of ecological land use. According to the trend of change over the past decade, the study has the great significance to the ecological security pattern so that we can effectively guide to take management strategy for security landscape.
文摘A supercell of a nanotube formed by a carbon nanotube (CNT) and a silicon nanotube (SiNT) is established. The electronic structure and optical properties are implemented through the first-principles method based on the density functional theory (DFT) with the generalized gradient approximation (GGA). The calculated results show that (6, 6) - (6, 6) silicon/carbon nanotubes (Si/CNTs) presented a direct band gap of 0.093 eV, (4, 4) - (6, 6) silicon/carbon nanotubes presented a direct band gap of 0.563 eV. The top of valence band was fundamentally determined by the Si-3p states and C-2p states, and the bottom of conduction band was primarily occupied by the C-2p states and Si-3p states in the Si/CNTs. It was found that (6, 6) - (6, 6) Si/CNTs have smaller energy band gap and better conductivity. Besides, Si/CNTs have satisfactory absorption characteristics and luminous efficiency in ultraviolet band.
基金The research work was supported by National Natural Science Foundation of China(grant No.81970847).
文摘Background:Spontaneously resolved primary congenital glaucoma is rare and the mechanism remains unknown.Previous literature described the phenomenon of spontaneous resolution of primary congenital glaucoma,with no further reports on follow-up visits and visual development of patients.We report a case of unilateral spontaneously resolved primary congenital glaucoma at a 7-year follow-up visit and describe the differential development of axial length(AL)between affected eye and healthy eye.Case Description:A 6-year-old boy firstly presented at Zhongshan Ophthalmic Center with expanded corneas and ruptures in Descemet’s membranes(Haab’s striae)and apparently thin retinal nerve fiber layer(RNFL)in the left eye(LE),but normal intraocular pressure(IOP)of both eyes without anti-glaucoma medications or surgeries.At 7-year follow-up,the IOPs of bilateral eyes were stable ranging from 8 to 11 mmHg.A cup to disc ratio and the RNFL was stable in the LE at the following visit.The AL increased almost 3 mm in the right eye(RE)but 1.5 mm in the LE.Without anti-glaucoma medications or surgeries,the primary congenital glaucoma was spontaneously resolved.Conclusions:It may figure out the development and influence of the affected eye of the patient,including AL and refraction state with regular ophthalmic examination at periodic follow-up.
基金This work was supported by the China Scholarship Council[grant number 201706195004]the National Natural Science Foundation of China[grant numbers 41001093 and 51778278]the Social Science Foundation of Jiangsu Province,China[grant number 18GLB014].
文摘As a well-known urban landscape concept to describe urban space quality,urban street vitality is a subjective human perception of the urban environment but difficult to evaluate directly from the physical space.The study utilized a modern machine learning computer vision algorithm in the urban build environment to simulate the process,which starts with the visual perception of the urban street landscape and ends with the human reaction to street vitality.By analyzing the optimized trained model,we tried to identify urban street vitality’s visual features and evaluate their importance.A region around the Mochou Lake in Nanjing,China,was set as our study area.Seven investigators surveyed the area,recorded their evaluation score on each site’s vitality level with a corresponding picture taken on site.A total of 370 pictures and recorded score pairs from 231 valid survey sites were used to train a convolutional neural network.After optimization,a deep neural network model with 43 layers,including 11 convolutional ones,was created.Heat maps were then used to identify the features which lead to high vitality score outputs.The spatial distributions of different types of feature entities were also analyzed to help identify the spatial effects.The study found that visual features,including human,construction site,shop front,and roadside/walking pavement,are vital ones that correspond to the vitality of the urban street.The consistency of these critical features with traditional urban vitality features indicates the model had learned useful knowledge from the training process.Applying the trained model in urban planning practices can help to improve the city environment for better attraction of residents’activities and communications.
