A Location-Based Service(LBS)refers to geolocation-based services that bring both convenience and vulnerability.With an increase in the scale and value of data,most existing location privacy protection protocols canno...A Location-Based Service(LBS)refers to geolocation-based services that bring both convenience and vulnerability.With an increase in the scale and value of data,most existing location privacy protection protocols cannot balance privacy and utility.To solve the revealing problems in LBS,we propose a differential privacy protection protocol based on location entropy.First,we design an algorithm of the best-assisted user selection for constructing anonymity sets.Second,we employ smart contracts to evaluate the credibility of participants,which ensures the honesty of participants.Moreover,we provide a comprehensive experiment;the theoretical analysis and experiments show that the proposed protocol effectively resists background knowledge attacks.Generally,our protocol improves data availability.Particularly,it realizes user-controllable privacy protection,which improves privacy protection and strengthens security.展开更多
Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization...Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization. Based on land use data of Liangshan Yi Autonomous Prefecture(hereinafter referred to as Liangshan Prefecture) in Sichuan Province, China from 1980 to 2020, compactness index, fractal dimension, imbalance index, location entropy and the optimal parameters-based geographical detector(OPGD) model are used to analyze the spatial-temporal evolution of the morphological characteristics of rural settlements, and to explore the influence of natural geographical factors, socioeconomic factors, and policy factors on the spatial differentiation of rural settlements. The results show that:(1) From 1980 to 2020, the rural settlements area in Liangshan Prefecture increased by 15.96 km^(2). In space, the rural settlements are generally distributed in a local aggregation, dense in the middle and sparse around the periphery. In 2015, the spatial density and expansion index of rural settlements reached the peak.(2) From 1980 to 2020, the compactness index decreased from 0.7636 to 0.7496, the fractal dimension increased from 1.0283 to 1.0314, and the fragmentation index decreased from 0.1183 to 0.1047. The spatial morphological structure of rural settlements tended to be loose, the shape contour tended to be complex, the degree of fragmentation decreased, and the spatial distribution was significantly imbalanced.(3) The results of OPGD detection in 2015 show that the influence of each factor is slope(0.2371) > traffic accessibility(0.2098) > population(0.1403) > regional GDP(0.1325) > elevation(0.0987) > poverty alleviation(0). The results of OPGD detection in 2020 show that the influence of each factor is slope(0.2339) > traffic accessibility(0.2198) > population(0.1432) > regional GDP(0.1219) > poverty alleviation(0.0992) > elevation(0.093). Natural geographical factors(slope and elevation) are the basic factors affecting the spatial distribution of rural settlements, and rural settlements are widely distributed in the river valley plain and the second half mountain area. Socioeconomic factors(traffic accessibility, population, and regional GDP) have a greater impact on the spatial distribution of rural settlements, which is an important factor affecting the spatial distribution of rural settlements. Policy factors such as poverty alleviation relocation have an indispensable impact on the spatial distribution of rural settlements. The research results can provide decisionmaking basis for the spatial arrangement of rural settlements in Liangshan Prefecture, and optimize the implementation of rural revitalization policies.展开更多
[Objective] The paper aimed to reflect the spatial pattern and temporal and spatial evolution characteristics, the differences between inter-regional tourism economy was measured from the quality aspect, which provide...[Objective] The paper aimed to reflect the spatial pattern and temporal and spatial evolution characteristics, the differences between inter-regional tourism economy was measured from the quality aspect, which provided a reference for the local governments in the future tourism development. [Method] Using the location entropy methods, three time periods side of tourism-related date of 2000, 2005, 2007 were selected, from the angle of the spatial pattern and the evolution of the differences within the different scales, the spatial and temporal evolution characteristics of the economic development level of Jiangsu were analysed. [Result] The results showed that from the aspect of spatial evolution pattern, as time goes on, the economic development of Jiangsu tourism has experienced morphological evolution of concentration- dispersion decrease-stability; when it comes to the development of the tourism economy, in recent years, the overall gap between the tourism economy in Jiangsu did not widen, the gap mainly led by the region one after another. According to their volatility, it will be divided into four categories: A Stable type (Wuxi, Xuzhou, Lianyungang and Taizhou), B Increasing type (Huai’an), C Fluctuations type (Nanjing, Changzhou, Suzhou and Yangzhou) and D Depression type (Nantong, Yancheng, Zhenjiang and Suqian). [Conclusion] Location entropy was quoted into tourism economic analysis, the method was simple and easy to understand, the result was accurate and convincing, which provided a reference for travel economic development and investment decision-making of Jiangsu.展开更多
基金This study was supported by the National Natura Science Foundation of China(No.61962009)Major Scientific and Technological Special Project of Guizhou Province(No.20183001)+1 种基金Science and Technology Support Plan of Guizhou Province(No.[2020]2Y011)the Foundation of Guizhou Provincial Key Laboratory of Public Big Data(No.2018BDKFJJ005).
文摘A Location-Based Service(LBS)refers to geolocation-based services that bring both convenience and vulnerability.With an increase in the scale and value of data,most existing location privacy protection protocols cannot balance privacy and utility.To solve the revealing problems in LBS,we propose a differential privacy protection protocol based on location entropy.First,we design an algorithm of the best-assisted user selection for constructing anonymity sets.Second,we employ smart contracts to evaluate the credibility of participants,which ensures the honesty of participants.Moreover,we provide a comprehensive experiment;the theoretical analysis and experiments show that the proposed protocol effectively resists background knowledge attacks.Generally,our protocol improves data availability.Particularly,it realizes user-controllable privacy protection,which improves privacy protection and strengthens security.
基金funded by the National Natural Science Foundation of China (Grant Nos. 41971015)Doctoral research program of China West Normal University (Grant Nos.19E067)。
文摘Rural settlement is the basic spatial unit for compact communities in rural area. Scientific exploration of spatial-temporal differentiation and its influencing factors is the premise of spatial layout rationalization. Based on land use data of Liangshan Yi Autonomous Prefecture(hereinafter referred to as Liangshan Prefecture) in Sichuan Province, China from 1980 to 2020, compactness index, fractal dimension, imbalance index, location entropy and the optimal parameters-based geographical detector(OPGD) model are used to analyze the spatial-temporal evolution of the morphological characteristics of rural settlements, and to explore the influence of natural geographical factors, socioeconomic factors, and policy factors on the spatial differentiation of rural settlements. The results show that:(1) From 1980 to 2020, the rural settlements area in Liangshan Prefecture increased by 15.96 km^(2). In space, the rural settlements are generally distributed in a local aggregation, dense in the middle and sparse around the periphery. In 2015, the spatial density and expansion index of rural settlements reached the peak.(2) From 1980 to 2020, the compactness index decreased from 0.7636 to 0.7496, the fractal dimension increased from 1.0283 to 1.0314, and the fragmentation index decreased from 0.1183 to 0.1047. The spatial morphological structure of rural settlements tended to be loose, the shape contour tended to be complex, the degree of fragmentation decreased, and the spatial distribution was significantly imbalanced.(3) The results of OPGD detection in 2015 show that the influence of each factor is slope(0.2371) > traffic accessibility(0.2098) > population(0.1403) > regional GDP(0.1325) > elevation(0.0987) > poverty alleviation(0). The results of OPGD detection in 2020 show that the influence of each factor is slope(0.2339) > traffic accessibility(0.2198) > population(0.1432) > regional GDP(0.1219) > poverty alleviation(0.0992) > elevation(0.093). Natural geographical factors(slope and elevation) are the basic factors affecting the spatial distribution of rural settlements, and rural settlements are widely distributed in the river valley plain and the second half mountain area. Socioeconomic factors(traffic accessibility, population, and regional GDP) have a greater impact on the spatial distribution of rural settlements, which is an important factor affecting the spatial distribution of rural settlements. Policy factors such as poverty alleviation relocation have an indispensable impact on the spatial distribution of rural settlements. The research results can provide decisionmaking basis for the spatial arrangement of rural settlements in Liangshan Prefecture, and optimize the implementation of rural revitalization policies.
文摘[Objective] The paper aimed to reflect the spatial pattern and temporal and spatial evolution characteristics, the differences between inter-regional tourism economy was measured from the quality aspect, which provided a reference for the local governments in the future tourism development. [Method] Using the location entropy methods, three time periods side of tourism-related date of 2000, 2005, 2007 were selected, from the angle of the spatial pattern and the evolution of the differences within the different scales, the spatial and temporal evolution characteristics of the economic development level of Jiangsu were analysed. [Result] The results showed that from the aspect of spatial evolution pattern, as time goes on, the economic development of Jiangsu tourism has experienced morphological evolution of concentration- dispersion decrease-stability; when it comes to the development of the tourism economy, in recent years, the overall gap between the tourism economy in Jiangsu did not widen, the gap mainly led by the region one after another. According to their volatility, it will be divided into four categories: A Stable type (Wuxi, Xuzhou, Lianyungang and Taizhou), B Increasing type (Huai’an), C Fluctuations type (Nanjing, Changzhou, Suzhou and Yangzhou) and D Depression type (Nantong, Yancheng, Zhenjiang and Suqian). [Conclusion] Location entropy was quoted into tourism economic analysis, the method was simple and easy to understand, the result was accurate and convincing, which provided a reference for travel economic development and investment decision-making of Jiangsu.
