Based on geographic information system(GIS) spatial analysis technology, the spatial pattern of raster grid transport accessibility for the Guangdong-Hong Kong-Macao Greater Bay area was studied and the states of spat...Based on geographic information system(GIS) spatial analysis technology, the spatial pattern of raster grid transport accessibility for the Guangdong-Hong Kong-Macao Greater Bay area was studied and the states of spatial connectedness were simulated using highway passenger transport, railway passenger transport, port passenger transport and aviation passenger transport data. The result shows that transport accessibility within the Guangdong-Hong Kong-Macao Greater Bay area costs ‘one hour’ and the spatial distribution of accessibility in the area presents clear ‘core-periphery’ spatial characteristics, with Guangzhou, Foshan, Shenzhen constituting the core. The transport accessibility of Guangdong-Hong Kong-Macao is high. Average accessibility of urban nodes as measured by travel time is 0.99 h, and the areas accessible within 1.42 h occupy 79.14% of the total area. Most of the areas with the lowest accessibility are found in the peripheral area, with the worst accessibility being 4.73 h. Compared with the west-side cities, the economically developed east-side cities of the Guangdong-Hong Kong-Macao Greater Bay area have higher connectivity with roads, railways, ports, and aviation transport. Guangzhou, Foshan, Zhuhai, Shenzhen, Hong Kong and Macao are closely linked. The higher the accessibility, the closer the intercity connectedness.展开更多
Under the background of ‘the Belt and Road’ initiative, the economic cooperation has great potential between China and Russia. The railway accessibility has an important influence on the economic connections of citi...Under the background of ‘the Belt and Road’ initiative, the economic cooperation has great potential between China and Russia. The railway accessibility has an important influence on the economic connections of cities along the railway line. This paper studied the Sino-Russian transnational economic connection based on the railway class accessibility along Trans-Siberian railway(the transnational China railway branch line). The results are as following. First, the railway accessibility of the Chinese nodes is stronger than that of the Russian nodes, which in general displays a tendency of space attenuation from China to the Sino-Russian border, then to Russia. Spatially, the railway accessibility within the study area shows a ‘High East, Low West’ and ‘High South, Low North’ spatial pattern. The railway accessibility of the nodes, which are located at the beginning and end of the railway line, is weaker than those nodes located in the middle of the line. Second, the railway accessibility and external economic connection intensity summation of the nodes show a positive relationship along the railway line. The economic connection intensity summation of different nodes presents obvious regional differentiation. Finally, as economic connection network has evolved, the small world effect of Sino-Russian railway economic connection network becomes strong.展开更多
Connected automated vehicles(CAVs)rely heavily on intelligent algorithms and remote sensors.If the control center or on-board sensors are under cyber-attack due to the security vulnerability of wireless communication,...Connected automated vehicles(CAVs)rely heavily on intelligent algorithms and remote sensors.If the control center or on-board sensors are under cyber-attack due to the security vulnerability of wireless communication,it can cause significant damage to CAVs or passengers.The primary objective of this study is to model cyberattacked traffic flow and evaluate the impacts of cyber-attack on the traffic system filled with CAVs in a connected environment.Based on the analysis on environmental perception system and possible cyber-attacks on sensors,a novel lane-changing model for CAVs is proposed and multiple traffic scenarios for cyber-attacks are designed.The impact of the proportion of cyber-attacked vehicles and the severity of the cyber-attack on the lanechanging process is then quantitatively analyzed.The evaluation indexes include spatio-temporal evolution of average speed,spatial distribution of selected lane-changing gaps,lane-changing rate distribution,lane-changing preparation search time,efficiency and safety.Finally,the numerical simulation results show that the freeway traffic near an off-ramp is more sensitive to the proportion of cyber-attacked vehicles than to the severity of the cyber-attack.Also,when the traffic system is under cyber-attack,more unsafe back gaps are chosen for lane-changing,especially in the center lane.Therefore,more lane-changing maneuvers are concentrated on approaching the off-ramp,causing severe congestions and potential rear-end collisions.In addition,as the number of cyber-attacked vehicles and the severity of cyber-attacks increase,the road capacity and safety level will rapidly decrease.The results of this study can provide a theoretical basis for accident avoidance and efficiency improvement for the design of CAVs and management of automated highway systems.展开更多
The environmental and health implications of Active Transportation (AT) strategies at the University of Manitoba’s Fort Garry campus in Canada were investigated, focusing on walking, biking, and public transit use of...The environmental and health implications of Active Transportation (AT) strategies at the University of Manitoba’s Fort Garry campus in Canada were investigated, focusing on walking, biking, and public transit use of students and staff. We analyzed connectivity, planning, and campus-city integration through mapping, observation, and transportation plan analysis. We found large gaps in connectivity of AT routes within the campus, a lack of AT planning, and poor AT city-campus integration, which explain why AT is decreasing rather than increasing, undermining sustainability on campus. Investing in biking, walking, and bus infrastructure and programs can be a practical, educational, and economical solution to negative environmental, safety, and health impacts posed by vehicles. Universities like the University of Manitoba (UM) have the potential to be leaders in creating an AT ecosystem that mitigates climate change through transportation and turns around the global problem of youth inactivity.展开更多
Pocket parks,defined as small-scale urban green spaces,have the potential to foster diverse ecological,cultural,social,and economic development in high-density cities.Under the dimension of spatial justice,pocket park...Pocket parks,defined as small-scale urban green spaces,have the potential to foster diverse ecological,cultural,social,and economic development in high-density cities.Under the dimension of spatial justice,pocket parks are acknowledged as a significant carrier for promoting the equitable distribution of green spaces and fostering social inclusion.The incorporation of appropriate green strategies and community participatory design methods can significantly enhance the sense of belonging and overall experience of local residents.This approach not only aligns the social values associated with pocket parks with the specific needs of the community but also fosters equitable citizen participation in both decisionmaking and design processes.This study proposes a comprehensive theoretical framework for the integration of pocket parks into green infrastructure networks.It aims to explore strategies for maximizing the value of pocket parks within the concept of spatial justice,emphasizing the fundamental principles of accessibility to green spaces and landscape connectivity.展开更多
Sparse code multiple access(SCMA) is a novel non-orthogonal multiple access technology considered as a key component in 5G air interface design. In SCMA, the incoming bits are directly mapped to multi-dimensional cons...Sparse code multiple access(SCMA) is a novel non-orthogonal multiple access technology considered as a key component in 5G air interface design. In SCMA, the incoming bits are directly mapped to multi-dimensional constellation vectors known as SCMA codewords, which are then mapped onto blocks of physical resource elements in a sparse manner. The number of codewords that can be non-orthogonally multiplexed in each SCMA block is much larger than the number of resource elements therein, so the system is overloaded and can support larger number of users. The joint optimization of multi-dimensional modulation and low density spreading in SCMA codebook design ensures the SCMA receiver to recover the coded bits with high reliability and low complexity. The flexibility in design and the robustness in performance further prove SCMA to be a promising technology to meet the 5G communication demands such as massive connectivity and low latency transmissions.展开更多
Digital transformation has been corner stone of business innovation in the last decade, and these innovations have dramatically changed the definition and boundaries of enterprise business applications. Introduction o...Digital transformation has been corner stone of business innovation in the last decade, and these innovations have dramatically changed the definition and boundaries of enterprise business applications. Introduction of new products/ services, version management of existing products/ services, management of customer/partner connections, management of multi-channel service delivery (web, social media, web etc.), merger/acquisitions of new businesses and adoption of new innovations/technologies will drive data growth in business applications. These datasets exist in different sharing nothing business applications at different locations and in various forms. So, to make sense of this information and derive insight, it is essential to break the data silos, streamline data retrieval and simplify information access across the entire organization. The information access framework must support just-in-time processing capabilities to bring data from multiple sources, be fast and powerful enough to transform and process huge amounts of data quickly, and be agile enough to accommodate new data sources per user needs. This paper discusses the SAP HANA Smart Data Access data-virtualization technology to enable unified access to heterogenous data across the organization and analysis of huge volume of data in real-time using SAP HANA in-memory platform.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41671160,41701169)
文摘Based on geographic information system(GIS) spatial analysis technology, the spatial pattern of raster grid transport accessibility for the Guangdong-Hong Kong-Macao Greater Bay area was studied and the states of spatial connectedness were simulated using highway passenger transport, railway passenger transport, port passenger transport and aviation passenger transport data. The result shows that transport accessibility within the Guangdong-Hong Kong-Macao Greater Bay area costs ‘one hour’ and the spatial distribution of accessibility in the area presents clear ‘core-periphery’ spatial characteristics, with Guangzhou, Foshan, Shenzhen constituting the core. The transport accessibility of Guangdong-Hong Kong-Macao is high. Average accessibility of urban nodes as measured by travel time is 0.99 h, and the areas accessible within 1.42 h occupy 79.14% of the total area. Most of the areas with the lowest accessibility are found in the peripheral area, with the worst accessibility being 4.73 h. Compared with the west-side cities, the economically developed east-side cities of the Guangdong-Hong Kong-Macao Greater Bay area have higher connectivity with roads, railways, ports, and aviation transport. Guangzhou, Foshan, Zhuhai, Shenzhen, Hong Kong and Macao are closely linked. The higher the accessibility, the closer the intercity connectedness.
基金Under the auspices of National Science and Technology Basic Project of the Ministry of Science and Technology of China(No.2017FY101303-1)National Natural Science Foundation of China(No.41571152,41771179)the Knowledge Innovation Program of CAS(No.ZDRW-ZS-2017-4-3-4,ZDBS-SSW-SQC)
文摘Under the background of ‘the Belt and Road’ initiative, the economic cooperation has great potential between China and Russia. The railway accessibility has an important influence on the economic connections of cities along the railway line. This paper studied the Sino-Russian transnational economic connection based on the railway class accessibility along Trans-Siberian railway(the transnational China railway branch line). The results are as following. First, the railway accessibility of the Chinese nodes is stronger than that of the Russian nodes, which in general displays a tendency of space attenuation from China to the Sino-Russian border, then to Russia. Spatially, the railway accessibility within the study area shows a ‘High East, Low West’ and ‘High South, Low North’ spatial pattern. The railway accessibility of the nodes, which are located at the beginning and end of the railway line, is weaker than those nodes located in the middle of the line. Second, the railway accessibility and external economic connection intensity summation of the nodes show a positive relationship along the railway line. The economic connection intensity summation of different nodes presents obvious regional differentiation. Finally, as economic connection network has evolved, the small world effect of Sino-Russian railway economic connection network becomes strong.
基金jointly supported by the National Key Research and Development Program of China(No.2022ZD0115600)National Natural Science Foundation of China(No.52072067)+3 种基金Natural Science Foundation of Jiangsu Province(No.BK20210249)China Postdoctoral Science Foundation(No.2020M681466)Jiangsu Planned Projects for Postdoctoral Research Funds(No.SBK2021041144)Jiangsu Planned Projects for Postdoctoral Research Funds(No.2021K094A)。
文摘Connected automated vehicles(CAVs)rely heavily on intelligent algorithms and remote sensors.If the control center or on-board sensors are under cyber-attack due to the security vulnerability of wireless communication,it can cause significant damage to CAVs or passengers.The primary objective of this study is to model cyberattacked traffic flow and evaluate the impacts of cyber-attack on the traffic system filled with CAVs in a connected environment.Based on the analysis on environmental perception system and possible cyber-attacks on sensors,a novel lane-changing model for CAVs is proposed and multiple traffic scenarios for cyber-attacks are designed.The impact of the proportion of cyber-attacked vehicles and the severity of the cyber-attack on the lanechanging process is then quantitatively analyzed.The evaluation indexes include spatio-temporal evolution of average speed,spatial distribution of selected lane-changing gaps,lane-changing rate distribution,lane-changing preparation search time,efficiency and safety.Finally,the numerical simulation results show that the freeway traffic near an off-ramp is more sensitive to the proportion of cyber-attacked vehicles than to the severity of the cyber-attack.Also,when the traffic system is under cyber-attack,more unsafe back gaps are chosen for lane-changing,especially in the center lane.Therefore,more lane-changing maneuvers are concentrated on approaching the off-ramp,causing severe congestions and potential rear-end collisions.In addition,as the number of cyber-attacked vehicles and the severity of cyber-attacks increase,the road capacity and safety level will rapidly decrease.The results of this study can provide a theoretical basis for accident avoidance and efficiency improvement for the design of CAVs and management of automated highway systems.
文摘The environmental and health implications of Active Transportation (AT) strategies at the University of Manitoba’s Fort Garry campus in Canada were investigated, focusing on walking, biking, and public transit use of students and staff. We analyzed connectivity, planning, and campus-city integration through mapping, observation, and transportation plan analysis. We found large gaps in connectivity of AT routes within the campus, a lack of AT planning, and poor AT city-campus integration, which explain why AT is decreasing rather than increasing, undermining sustainability on campus. Investing in biking, walking, and bus infrastructure and programs can be a practical, educational, and economical solution to negative environmental, safety, and health impacts posed by vehicles. Universities like the University of Manitoba (UM) have the potential to be leaders in creating an AT ecosystem that mitigates climate change through transportation and turns around the global problem of youth inactivity.
基金Sponsored by Postgraduate Education Reform and Quality Improvement Project of Henan Province(YJS2023JC12).
文摘Pocket parks,defined as small-scale urban green spaces,have the potential to foster diverse ecological,cultural,social,and economic development in high-density cities.Under the dimension of spatial justice,pocket parks are acknowledged as a significant carrier for promoting the equitable distribution of green spaces and fostering social inclusion.The incorporation of appropriate green strategies and community participatory design methods can significantly enhance the sense of belonging and overall experience of local residents.This approach not only aligns the social values associated with pocket parks with the specific needs of the community but also fosters equitable citizen participation in both decisionmaking and design processes.This study proposes a comprehensive theoretical framework for the integration of pocket parks into green infrastructure networks.It aims to explore strategies for maximizing the value of pocket parks within the concept of spatial justice,emphasizing the fundamental principles of accessibility to green spaces and landscape connectivity.
基金supported by the National Basic Research Program of China(973 Program 2012CB316000)the National Major Projects of China(2015ZX03002010)
文摘Sparse code multiple access(SCMA) is a novel non-orthogonal multiple access technology considered as a key component in 5G air interface design. In SCMA, the incoming bits are directly mapped to multi-dimensional constellation vectors known as SCMA codewords, which are then mapped onto blocks of physical resource elements in a sparse manner. The number of codewords that can be non-orthogonally multiplexed in each SCMA block is much larger than the number of resource elements therein, so the system is overloaded and can support larger number of users. The joint optimization of multi-dimensional modulation and low density spreading in SCMA codebook design ensures the SCMA receiver to recover the coded bits with high reliability and low complexity. The flexibility in design and the robustness in performance further prove SCMA to be a promising technology to meet the 5G communication demands such as massive connectivity and low latency transmissions.
文摘Digital transformation has been corner stone of business innovation in the last decade, and these innovations have dramatically changed the definition and boundaries of enterprise business applications. Introduction of new products/ services, version management of existing products/ services, management of customer/partner connections, management of multi-channel service delivery (web, social media, web etc.), merger/acquisitions of new businesses and adoption of new innovations/technologies will drive data growth in business applications. These datasets exist in different sharing nothing business applications at different locations and in various forms. So, to make sense of this information and derive insight, it is essential to break the data silos, streamline data retrieval and simplify information access across the entire organization. The information access framework must support just-in-time processing capabilities to bring data from multiple sources, be fast and powerful enough to transform and process huge amounts of data quickly, and be agile enough to accommodate new data sources per user needs. This paper discusses the SAP HANA Smart Data Access data-virtualization technology to enable unified access to heterogenous data across the organization and analysis of huge volume of data in real-time using SAP HANA in-memory platform.
