Cloud computing provides a new paradigm for hardware and software infrastructure design as well as planning and usage of information systems. It offers flexible, efficient, inexpensive, and quality services. This pape...Cloud computing provides a new paradigm for hardware and software infrastructure design as well as planning and usage of information systems. It offers flexible, efficient, inexpensive, and quality services. This paper proposes an on-demand service system using the cloud computing architecture and analyzes important issues such as organization, management, and monitoring of distributed service resources; context-aware on-demand service modeling, on-demand automated service composition in large-scale networks, and service system analysis based on complex system theory. Continuous Operating Reference Station （CORS） of a geo-spatial information system is taken as an example, and its architecture is analyzed from the perspective of cloud computing. Some fundamental questions are raised about its service.展开更多
The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous ser...The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous services for user terminals. However, global traffic demands present nonuniform characteristics. Therefore, how to ensure the on-demand service coverage for the specific traffic demand, i.e., the ratio of traffic density to service requirement per unit area, is the core issue of 6G wireless coverage extension exploiting the MSC. To this regard, this paper first discusses the open challenges to reveal the future direction of 6G wireless coverage extension from the perspective of key factors affecting service coverage performance, i.e., the network access capacity, space segment capacity and their matchingrelationship. Furthermore, we elaborate on the key factors affecting effective matchings of the aforementioned aspects, thereby improving service coverage capability.展开更多
With the acceleration of the pace of social life and the emergence of the convenience economy,the requirements for on-demand cooking services have increased due to the increasing demand for food quality and the health...With the acceleration of the pace of social life and the emergence of the convenience economy,the requirements for on-demand cooking services have increased due to the increasing demand for food quality and the health concerns associated with takeaway food,as well as the lack of cooking skills.This paper aims to analyze the business model of on-demand cooking service platforms in China with the theory of Business Model Canvas proposed by Alexander Osterwalder.By exploring the advantages and disadvantages of the business model of on-demand door-to-door cooking,the study seeks to provide relevant recommendations.展开更多
Travel time reliability is of increasing importance for travelers, shippers, and transportation managers because traffic congestion has become worse in major urban areas in recent years. To better evaluate the urban n...Travel time reliability is of increasing importance for travelers, shippers, and transportation managers because traffic congestion has become worse in major urban areas in recent years. To better evaluate the urban network-wide travel time reliability, five indices based on the emerging on-demand ride service data are proposed:network free flow time rate(NFFTR), network travel time rate(NTTR), network planning time rate(NPTR), network buffer time rate(NBTR), and network buffer time rate index(NBTRI). These indices take into account the probability distribution of the travel time rate(i.e., travel time spent for the unit distance, in min/km) of each origindestination(OD) pair in the road network. We use realworld data extracted from DiDi-Chuxing, which is the largest on-demand ride service platform in China. For demonstrative purposes, the network-wide travel time reliability of Beijing is analyzed in detail from two dimensions of time and space. The results show that the road network is more unreliable in AM/PM peaks than other time periods, and the most reliable time period is the early morning. Additionally, we can find that the central region is more unreliable than other regions of the city based on the spatial analysis results. The proposed network travel time reliability indices provide insights for the comprehensive evaluation of the road network traffic dynamics and day-to-day travel time variations.展开更多
基金funded by the National Basic Research Program of China ("973" Program) under Grant No. 2007CB310805the National High Technology Research and Development Program of China ("863" Program) under Grant No. 2007AA12Z309
文摘Cloud computing provides a new paradigm for hardware and software infrastructure design as well as planning and usage of information systems. It offers flexible, efficient, inexpensive, and quality services. This paper proposes an on-demand service system using the cloud computing architecture and analyzes important issues such as organization, management, and monitoring of distributed service resources; context-aware on-demand service modeling, on-demand automated service composition in large-scale networks, and service system analysis based on complex system theory. Continuous Operating Reference Station （CORS） of a geo-spatial information system is taken as an example, and its architecture is analyzed from the perspective of cloud computing. Some fundamental questions are raised about its service.
基金supported in part by the National Key R&D Program of China under Grant 2020YFB1806100in part by the Natural Science Foundation of China under Grants U19B2025, 62121001, 62001347, and 61801361。
文摘The rapid development and continuous updating of the mega satellite constellation(MSC)have brought new visions for the future 6G coverage extension, where the global seamless signal coverage can realize ubiquitous services for user terminals. However, global traffic demands present nonuniform characteristics. Therefore, how to ensure the on-demand service coverage for the specific traffic demand, i.e., the ratio of traffic density to service requirement per unit area, is the core issue of 6G wireless coverage extension exploiting the MSC. To this regard, this paper first discusses the open challenges to reveal the future direction of 6G wireless coverage extension from the perspective of key factors affecting service coverage performance, i.e., the network access capacity, space segment capacity and their matchingrelationship. Furthermore, we elaborate on the key factors affecting effective matchings of the aforementioned aspects, thereby improving service coverage capability.
文摘With the acceleration of the pace of social life and the emergence of the convenience economy,the requirements for on-demand cooking services have increased due to the increasing demand for food quality and the health concerns associated with takeaway food,as well as the lack of cooking skills.This paper aims to analyze the business model of on-demand cooking service platforms in China with the theory of Business Model Canvas proposed by Alexander Osterwalder.By exploring the advantages and disadvantages of the business model of on-demand door-to-door cooking,the study seeks to provide relevant recommendations.
基金financially supported by Zhejiang Provincial Natural Science Foundation of China [Grant No. LR17E080002]Key Laboratory of Road & Traffic Engineering of the Ministry of Education [Grant No. TJDDZHCX004]+1 种基金National Natural Science Foundation of China[Grant Nos. 51508505, 71771198, 51338008]Fundamental Research Funds for the Central Universities [Grant No. 2017QNA4025]
文摘Travel time reliability is of increasing importance for travelers, shippers, and transportation managers because traffic congestion has become worse in major urban areas in recent years. To better evaluate the urban network-wide travel time reliability, five indices based on the emerging on-demand ride service data are proposed:network free flow time rate(NFFTR), network travel time rate(NTTR), network planning time rate(NPTR), network buffer time rate(NBTR), and network buffer time rate index(NBTRI). These indices take into account the probability distribution of the travel time rate(i.e., travel time spent for the unit distance, in min/km) of each origindestination(OD) pair in the road network. We use realworld data extracted from DiDi-Chuxing, which is the largest on-demand ride service platform in China. For demonstrative purposes, the network-wide travel time reliability of Beijing is analyzed in detail from two dimensions of time and space. The results show that the road network is more unreliable in AM/PM peaks than other time periods, and the most reliable time period is the early morning. Additionally, we can find that the central region is more unreliable than other regions of the city based on the spatial analysis results. The proposed network travel time reliability indices provide insights for the comprehensive evaluation of the road network traffic dynamics and day-to-day travel time variations.
