With the rapid development of the Internet of Things(IoT),Location-Based Services(LBS)are becoming more and more popular.However,for the users being served,how to protect their location privacy has become a growing co...With the rapid development of the Internet of Things(IoT),Location-Based Services(LBS)are becoming more and more popular.However,for the users being served,how to protect their location privacy has become a growing concern.This has led to great difficulty in establishing trust between the users and the service providers,hindering the development of LBS for more comprehensive functions.In this paper,we first establish a strong identity verification mechanism to ensure the authentication security of the system and then design a new location privacy protection mechanism based on the privacy proximity test problem.This mechanism not only guarantees the confidentiality of the user s information during the subsequent information interaction and dynamic data transmission,but also meets the service provider's requirements for related data.展开更多
With the evolution of location-based services(LBS),a new type of LBS has already gain a lot of attention and implementation,we name this kind of LBS as the Device-Dependent LBS(DLBS).In DLBS,the service provider(SP)wi...With the evolution of location-based services(LBS),a new type of LBS has already gain a lot of attention and implementation,we name this kind of LBS as the Device-Dependent LBS(DLBS).In DLBS,the service provider(SP)will not only send the information according to the user’s location,more significant,he also provides a service device which will be carried by the user.DLBS has been successfully practised in some of the large cities around the world,for example,the shared bicycle in Beijing and London.In this paper,we,for the first time,blow the whistle of the new location privacy challenges caused by DLBS,since the service device is enabled to perform the localization without the permission of the user.To conquer these threats,we design a service architecture along with a credit system between DLBS provider and the user.The credit system tie together the DLBS device usability with the curious behaviour upon user’s location privacy,DLBS provider has to sacrifice their revenue in order to gain extra location information of their device.We make the simulation of our proposed scheme and the result convince its effectiveness.展开更多
Internet takes a role as a place for communication between people beyond a space simply for the acquisition of information.Recently,social network service(SNS)reflecting human’s basic desire for talking and communica...Internet takes a role as a place for communication between people beyond a space simply for the acquisition of information.Recently,social network service(SNS)reflecting human’s basic desire for talking and communicating with others is focused on around the world.And location-based service(LBS)is a service that provides various life conveniences like improving productivity through location information,such as GPS and WiFi.This paper suggests an application combining LBS and SNS based on Android OS.By using smart phone which is personal mobile information equipment,it combines location information with user information and SNS so that the service can be developed.It also maximizes sharing and use of information via twit based on locations of friends.This proposed system is aims for users to show online identity more actively and more conveniently.展开更多
Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simp...Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.展开更多
Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is t...Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is then introduced and a correction is given, which especially emphasizes that location property is an important part of semantic location. By analyzing the connotation and extension of every geographic location, what should be contained in a location property is determined. Using a hierarchical model, the relations and associations among locations are clearly described. To realize a formalized description of semantic location, an ontology technique that can adequately describe semantic information of location is used. Organized by ontology web language, a location ontology model allows semantic location to be read and processed by computer. The location ontology model realizes the knowledge description of location information and establishes an important foundation to personalized preference services in location based services.展开更多
Homomorphic encryption schemes make it possible to perform arithmetic operations, like additions and multiplications, over encrypted values. This capability provides enhanced protection for data and offers new researc...Homomorphic encryption schemes make it possible to perform arithmetic operations, like additions and multiplications, over encrypted values. This capability provides enhanced protection for data and offers new research directions, including blind data processing. Using homomorphic encryption schemes, a Location-Based Service (LBS) can process encrypted inputs to retrieve encrypted location-related information. The retrieved encrypted data can only be decrypted by the user who requested the data. The technology still faces two main challenges: the encountered processing time and the upper limit imposed on the allowed number of operations. However, the protection of users’ privacy achieved through this technology makes it attractive for more research and enhancing. In this paper we use homomorphic encryption schemes to build a fully secure system that allows users to benefit from location-based services while preserving the confidentiality and integrity of their data. Our novel system consists of search circuits that allow an executor (i.e. LBS server) to receive encrypted inputs/requests and then perform a blind search to retrieve encrypted records that match the selection criterion. A querier can send the user’s position and the service type he/she is looking for, in encrypted form, to a server and then the server would respond to the request without any knowledge of the contents of the request and the retrieved records. We further propose a prototype that improves the practicality of our system.展开更多
Casper Cloak is a privacy protection method based on K-anonymity algorithm. To be anonymous, Casper Cloak needs to search regional sibling and parent node, which requires a complex process and huge expenditure. In add...Casper Cloak is a privacy protection method based on K-anonymity algorithm. To be anonymous, Casper Cloak needs to search regional sibling and parent node, which requires a complex process and huge expenditure. In addition,the anonymous area has space redundancy and it is not accurate enough to achieve high Location-Based Services (LBS) quality. To address these problems,this paper proposes an improved privacy protection method-NCC, based on the Casper Cloak. To reduce the unnecessary search, NCC introduced the concept of the first sibling node. NCC also improves the LBS quality by considering the characteristics of user mobility. Moreover, the improved method,NCC, which is incorporated with a redundancy optimization processing strategy,realizing more precise in the anonymous area and accurately guaranteeing the related degree of privacy. Adopting NCC verification experiments reflects varied advantages as bellow: (1) By reducing 80% searching time, NCC highly improved searching process. (2) The anonymous area produced in NCC not only meet users' anonymous demands, but the direction of the mobility which improves 4 times accuracy of services in comparison with Casper mode.(3) According to optimization strategy, NCC can reach minimum anonymous area index, increasing the rates of anonymous optimization in original algorithm.展开更多
The widespread use of Location-Based Services （LBSs）, which allows untrusted service providers to collect large quantities of information regarding users＇ locations, has raised serious privacy concerns. In response...The widespread use of Location-Based Services （LBSs）, which allows untrusted service providers to collect large quantities of information regarding users＇ locations, has raised serious privacy concerns. In response to these issues, a variety of LBS Privacy Protection Mechanisms （LPPMs） have been recently proposed. However, evaluating these LPPMs remains problematic because of the absence of a generic adversarial model for most existing privacy metrics. In particular, the relationships between these metrics have not been examined in depth under a common adversarial model, leading to a possible selection of the inappropriate metric, which runs the risk of wrongly evaluating LPPMs. In this paper, we address these issues by proposing a privacy quantification model, which is based on Bayes conditional privacy, to specify a general adversarial model. This model employs a general definition of conditional privacy regarding the adversary＇s estimation error to compare the different LBS privacy metrics. Moreover, we present a theoretical analysis for specifying how to connect our metric with other popular LBS privacy metrics. We show that our privacy quantification model permits interpretation and comparison of various popular LBS privacy metrics under a common perspective. Our results contribute to a better understanding of how privacy properties can be measured, as well as to the better selection of the most appropriate metric for any given LBS application.展开更多
The authors compare key elements of the emerging field of Indoor Location-Based Services(Indoor LBS)to those currently found in spatial data infrastructure(SDI)programs.After a brief review of SDIs and Location-Based ...The authors compare key elements of the emerging field of Indoor Location-Based Services(Indoor LBS)to those currently found in spatial data infrastructure(SDI)programs.After a brief review of SDIs and Location-Based Services,the corresponding drivers,characteristics and emerging issues within the field of Indoor LBS are introduced and discussed.A comparative framework relates the two in terms of the criteria‘People’,‘Data’,‘Technologies’,‘Standards’and‘Policies/Institutional Arrangements’.After highlighting key similarities and differences,the authors suggested three areas–definition of common framework datasets in Indoor LBS,more effective use of volunteered geographic information by SDI programs and development of appropriate privacy policies by both communities–that may benefit from sharing‘lessons learned’.展开更多
Since smartphones embedded with positioning systems and digital maps are widely used,location-based services(LBSs)are rapidly growing in popularity and providing unprecedented convenience in people’s daily lives;howe...Since smartphones embedded with positioning systems and digital maps are widely used,location-based services(LBSs)are rapidly growing in popularity and providing unprecedented convenience in people’s daily lives;however,they also cause great concern about privacy leakage.In particular,location queries can be used to infer users’sensitive private information,such as home addresses,places of work and appointment locations.Hence,many schemes providing query anonymity have been proposed,but they typically ignore the fact that an adversary can infer real locations from the correlations between consecutive locations in a continuous LBS.To address this challenge,a novel dual privacy-preserving scheme(DPPS)is proposed that includes two privacy protection mechanisms.First,to prevent privacy disclosure caused by correlations between locations,a correlation model is proposed based on a hidden Markov model(HMM)to simulate users’mobility and the adversary’s prediction probability.Second,to provide query probability anonymity of each single location,an advanced k-anonymity algorithm is proposed to construct cloaking regions,in which realistic and indistinguishable dummy locations are generated.To validate the effectiveness and efficiency of DPPS,theoretical analysis and experimental verification are further performed on a real-life dataset published by Microsoft,i.e.,GeoLife dataset.展开更多
A novel testing framework for location based services is introduced. In particular, the paper showcases a novel architecture for such a framework. The implementation of the framework illustrates both the functionality...A novel testing framework for location based services is introduced. In particular, the paper showcases a novel architecture for such a framework. The implementation of the framework illustrates both the functionality and the feasibility of the framework proposed and the utility of the architecture. The new framework is evaluated through comparison to several other methodologies currently available for the testing of location-based applications. A case study is presented in which the testing framework was applied to a typical mobile service tracking system. It is concluded that the proposed testing framework achieves the best coverage of the entire location based service testing problem of the currently available methodologies; being equipped to test the widest array of application attributes and allowing for the automation of testing activities.展开更多
n the current world,it is easy to listen that everybody and everything is connected.Over this connected world,the concept of location-based services has grown in order to provide digital services in everyplace and at ...n the current world,it is easy to listen that everybody and everything is connected.Over this connected world,the concept of location-based services has grown in order to provide digital services in everyplace and at every time.Nevertheless,this is not 100%true because the connection is not guaranteed for many people and in many places.These are the Degraded Communications Environments(DCE),environments where the availability of high-speed communications is not guaranteed in at least the 75%of the time.This paper works over the experience of a previous work in developing light protocols that do not need broadband for communication.This work provides an extension of these protocols for the inclusion of mobile devices as elements of the communication process and a set of libraries to allow the development of applications in DCE.The work done has involved the development of two frameworks:an Android framework that makes the incorporation of Android devices easier and a server-based framework that provides the server side for the development of the referred applications.A use case that uses these two frameworks has been developed.Finally,all technology developed is available throw a public Git repository.展开更多
Saud Khan,a Pakistani physician,collected his work and residence permits at the Yangpu Government Service Centre in Danzhou City,Hainan Province,on 18 December 2025.Khan had arrived in Hainan three months earlier to p...Saud Khan,a Pakistani physician,collected his work and residence permits at the Yangpu Government Service Centre in Danzhou City,Hainan Province,on 18 December 2025.Khan had arrived in Hainan three months earlier to participate in a medical training programme at Hainan Western Central Hospital.By the time the programme concluded,he had made up his mind to stay and broaden his professional experience and long-term career prospects in Hainan.展开更多
Ensuring an information fabric safe is critical and mandatory.For its related Internet of Things(IoT)service system running on the open Internet,existing host-based monitoring methods may fail due to only inspecting s...Ensuring an information fabric safe is critical and mandatory.For its related Internet of Things(IoT)service system running on the open Internet,existing host-based monitoring methods may fail due to only inspecting software,and the physical system may not be able to be protected.In this paper,a nonintrusive virtual machine(VM)-based runtime protection framework is provided to protect the physical system with the isolated IoT services as a controlling means.Compared with existing solutions,the framework gets inconsistent and untrusted observation knowledge from multiple observation sources,and enforces property policies concurrently and incrementally in a competing-game way to avoid compositional problems.In addition,the monitoring is implemented without any modification to the protected system.Experiments are conducted to validate the proposed techniques.展开更多
Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for so...Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for social networks due to significant limitations.Specifically,most approaches depend mainly on user-user structural links while overlooking service-centric,semantic,and multi-attribute drivers of community formation,and they also lack flexible filtering mechanisms for large-scale,service-oriented settings.Our proposed approach,called community discovery-based service(CDBS),leverages user profiles and their interactions with consulted web services.The method introduces a novel similarity measure,global similarity interaction profile(GSIP),which goes beyond typical similarity measures by unifying user and service profiles for all attributes types into a coherent representation,thereby clarifying its novelty and contribution.It applies multiple filtering criteria related to user attributes,accessed services,and interaction patterns.Experimental comparisons against Louvain,Hierarchical Agglomerative Clustering,Label Propagation and Infomap show that CDBS reveals the higher performance as it achieves 0.74 modularity,0.13 conductance,0.77 coverage,and significantly fast response time of 9.8 s,even with 10,000 users and 400 services.Moreover,community discoverybased service consistently detects a larger number of communities with distinct topics of interest,underscoring its capacity to generate detailed and efficient structures in complex networks.These results confirm both the efficiency and effectiveness of the proposed method.Beyond controlled evaluation,communities discovery based service is applicable to targeted recommendations,group-oriented marketing,access control,and service personalization,where communities are shaped not only by user links but also by service engagement.展开更多
Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and st...Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and standardized discharge preparation intervention programs in clinical practice.Methods:Following the“5S”evidence model,literature such as guidelines,expert consensuses,evidence summaries and randomized controlled trials related to discharge preparation services for total knee arthroplasty patients were retrieved from relevant websites and databases,both domestic and international,from database inception to August 31,2025.Two researchers independently screened the literature,conducted quality appraisals,and extracted and synthesized the evidence.Results:A total of 15 articles were included,comprising 3 guidelines,4 expert consensuses,3 evidence summaries,3 systematic reviews and 2 randomized controlled trials.Ultimately,23 pieces of evidence were summarized across five aspects.Conclusion:This study synthesizes the evidence on discharge preparation services for patients undergoing total knee arthroplasty.It is recommended that healthcare professionals apply this evidence in clinical practice,considering specific circumstances and patient needs.展开更多
Location privacy has been a serious concern for mobile users who use location-based services provided by third-party providers via mobile networks. Recently, there have been tremendous efforts on developing new anonym...Location privacy has been a serious concern for mobile users who use location-based services provided by third-party providers via mobile networks. Recently, there have been tremendous efforts on developing new anonymity or obfuscation techniques to protect location privacy of mobile users. Though effective in certain scenarios, these existing techniques usually assume that a user has a constant privacy requirement along spatial and/or temporal dimensions, which may be not true in real-life scenarios. In this paper, we introduce a new location privacy problem： Location-aware Location Privacy Protection （L2P2） problem, where users can define dynamic and diverse privacy requirements for different locations. The goal of the L2P2 problem is to find the smallest cloaking area for each location request so that diverse privacy requirements over spatial and/or temporal dimensions are satisfied for each user. In this paper, we formalize two versions of the L2P2 problem, and propose several efficient heuristics to provide such location-aware location privacy protection for mobile users. Through extensive simulations over large synthetic and real-life datasets, we confirm the effectiveness and efficiency of the proposed L2P2 algorithms.展开更多
The Guangdong,Jiangxi and Fujian(GJF)provinces,located in the subtropical region of southeastern China,is one of the national key regions for soil erosion control and ecological restoration.This region is characterize...The Guangdong,Jiangxi and Fujian(GJF)provinces,located in the subtropical region of southeastern China,is one of the national key regions for soil erosion control and ecological restoration.This region is characterized by extensive red soil development and high rainfall erosivity,making it a representative landscape for exploring the interactions between land use change(LUC)and ecosystem services(ES).Despite the recognized importance of ES in hilly regions,comprehensive assessing the impacts of LUC on ES remain limited.This study investigates five key ES:water yield,soil conservation,carbon conservation,food supply,and habitat quality in GJF region from 2000 to 2020.By applying the InVEST model and the Geodetector method,we assessed the trade-offs,synergies,and transitions among ES,identified the natural and social drivers of ES dynamics,and quantified the contribution of LUC to ES changes using the ecosystem service contribution index.The results showed that cropland and woodland were the dominant land use types.Ecological restoration efforts positively influenced ES,with synergies intensifying and trade-offs diminishing over time.Land use conversions,particularly among woodland,grassland,and cropland,exerted significant impacts on ES.In particular,the conversion of woodland to other land uses had markedly negative effects on soil conservation,carbon conservation,and habitat quality.Forest cover was identified as a major driver of ES dynamics.These findings highlight the importance of maintaining and expanding forest and grassland cover,strengthening red soil conservation,and optimizing land use structure to achieve coordinated ecological protection and socioeconomic development in the subtropical hilly regions of southern China.展开更多
Ubiquitous information exchange is achieved among connected vehicles through the increasingly smart environment.The concept of conventional vehicular ad hoc network is gradually transformed into the Internet of vehicl...Ubiquitous information exchange is achieved among connected vehicles through the increasingly smart environment.The concept of conventional vehicular ad hoc network is gradually transformed into the Internet of vehicles(IoV).Meanwhile,more and more locationbased services(LBSs)are created to provide convenience for drivers.However,the frequently updated location information sent to the LBS server also puts user location privacy at risk.Thus,preserve user location privacy while allowing vehicles to have high-quality LBSs is a critical issue.Many solutions have been proposed in the literature to preserve location privacy.However,most of them cannot provide real-time LBS with accurate location updates.In this paper,we propose a novel location privacy-preserving scheme,which allows vehicles to send accurate real-time location information to the LBS server while preventing being tracked by attackers.In the proposed scheme,a vehicle utilizes the location information of selected shadow vehicles,whose route diverge from the requester,to generate multiple virtual trajectories to the LBS server so as to mislead attackers.Simulation results show that our proposed scheme achieves a high privacy-preserving level and outperforms other state-of-the-art schemes in terms of location entropy and tracking success ratio.展开更多
1 Introduction and main contributions Location-based services are springing up around us,while leakages of users'privacy are inevitable during services.Even worse,adversaries may analyze intercepted service data,a...1 Introduction and main contributions Location-based services are springing up around us,while leakages of users'privacy are inevitable during services.Even worse,adversaries may analyze intercepted service data,and extract more privacy like health and property.Therefore,privacy preservation is an indispensable guarantee on LBS security.Among the previous approaches to privacy preservation,k-anonymity-based ones have drawn much research attention[1-3].However,some privacy concern will be aroused if these schemes are adopted directly.For instance,Ut issues a query"Find the nearest hotel around me"in such an area as Fig.1(privacy profile k=4).DLS algorithm[2]constructs anonymity set A because these four cells have similar probabilities of being queried in the past.However,experienced adversaries can exclude some cells if they have learned rich contextual knowledge(side information)from historical data,such as features of each cell and LBS users.展开更多
基金This work has been partly supported by the National Natural Science Foundation of China under Grant No.61702212the Fundamental Research Funds for the Central Universities under Grand NO.CCNU19TS017.
文摘With the rapid development of the Internet of Things(IoT),Location-Based Services(LBS)are becoming more and more popular.However,for the users being served,how to protect their location privacy has become a growing concern.This has led to great difficulty in establishing trust between the users and the service providers,hindering the development of LBS for more comprehensive functions.In this paper,we first establish a strong identity verification mechanism to ensure the authentication security of the system and then design a new location privacy protection mechanism based on the privacy proximity test problem.This mechanism not only guarantees the confidentiality of the user s information during the subsequent information interaction and dynamic data transmission,but also meets the service provider's requirements for related data.
基金This work was supported by National Natural Science Foundation of China(Grant Nos.61871140,61702223,61702220,61572153,61723022,61601146)and the National Key research and Development Plan(Grant No.2018YFB0803504,2017YFB0803300).
文摘With the evolution of location-based services(LBS),a new type of LBS has already gain a lot of attention and implementation,we name this kind of LBS as the Device-Dependent LBS(DLBS).In DLBS,the service provider(SP)will not only send the information according to the user’s location,more significant,he also provides a service device which will be carried by the user.DLBS has been successfully practised in some of the large cities around the world,for example,the shared bicycle in Beijing and London.In this paper,we,for the first time,blow the whistle of the new location privacy challenges caused by DLBS,since the service device is enabled to perform the localization without the permission of the user.To conquer these threats,we design a service architecture along with a credit system between DLBS provider and the user.The credit system tie together the DLBS device usability with the curious behaviour upon user’s location privacy,DLBS provider has to sacrifice their revenue in order to gain extra location information of their device.We make the simulation of our proposed scheme and the result convince its effectiveness.
基金MKE(the Ministry of Knowledge Economy),Korea,under the ITRC(Infor mation Technology Research Center)support program supervised by the NIPA(National IT Industry Promotion Agency)(NIPA-2011-C1090-1121-0010)
文摘Internet takes a role as a place for communication between people beyond a space simply for the acquisition of information.Recently,social network service(SNS)reflecting human’s basic desire for talking and communicating with others is focused on around the world.And location-based service(LBS)is a service that provides various life conveniences like improving productivity through location information,such as GPS and WiFi.This paper suggests an application combining LBS and SNS based on Android OS.By using smart phone which is personal mobile information equipment,it combines location information with user information and SNS so that the service can be developed.It also maximizes sharing and use of information via twit based on locations of friends.This proposed system is aims for users to show online identity more actively and more conveniently.
文摘Location-Based Services (LBS),an emerging new business based on smartphone and mobile networks,are becoming more and more popular.Most of these LBSs,however,only offer non-seamless indoor/outdoor applications and simple applications without giving stakeholders the chance to play an active role.Our specific aim is to solve these issues.This paper presents concepts to solve these issues by expanding the Open Location Services Interface Standard (OpenLS) to allow seamless indoor/outdoor positioning and to extend the content of the services to include information recommended by stakeholders.
基金Supported by the Open Research Fund Program of the Geomatics and Applications Laboratory, Liaoning Technical University (No. 2005001).
文摘Starting with a simple presentation of location determination techniques, physical location and geographic location as two common kinds of location description methods are discussed. The semantic location concept is then introduced and a correction is given, which especially emphasizes that location property is an important part of semantic location. By analyzing the connotation and extension of every geographic location, what should be contained in a location property is determined. Using a hierarchical model, the relations and associations among locations are clearly described. To realize a formalized description of semantic location, an ontology technique that can adequately describe semantic information of location is used. Organized by ontology web language, a location ontology model allows semantic location to be read and processed by computer. The location ontology model realizes the knowledge description of location information and establishes an important foundation to personalized preference services in location based services.
文摘Homomorphic encryption schemes make it possible to perform arithmetic operations, like additions and multiplications, over encrypted values. This capability provides enhanced protection for data and offers new research directions, including blind data processing. Using homomorphic encryption schemes, a Location-Based Service (LBS) can process encrypted inputs to retrieve encrypted location-related information. The retrieved encrypted data can only be decrypted by the user who requested the data. The technology still faces two main challenges: the encountered processing time and the upper limit imposed on the allowed number of operations. However, the protection of users’ privacy achieved through this technology makes it attractive for more research and enhancing. In this paper we use homomorphic encryption schemes to build a fully secure system that allows users to benefit from location-based services while preserving the confidentiality and integrity of their data. Our novel system consists of search circuits that allow an executor (i.e. LBS server) to receive encrypted inputs/requests and then perform a blind search to retrieve encrypted records that match the selection criterion. A querier can send the user’s position and the service type he/she is looking for, in encrypted form, to a server and then the server would respond to the request without any knowledge of the contents of the request and the retrieved records. We further propose a prototype that improves the practicality of our system.
文摘Casper Cloak is a privacy protection method based on K-anonymity algorithm. To be anonymous, Casper Cloak needs to search regional sibling and parent node, which requires a complex process and huge expenditure. In addition,the anonymous area has space redundancy and it is not accurate enough to achieve high Location-Based Services (LBS) quality. To address these problems,this paper proposes an improved privacy protection method-NCC, based on the Casper Cloak. To reduce the unnecessary search, NCC introduced the concept of the first sibling node. NCC also improves the LBS quality by considering the characteristics of user mobility. Moreover, the improved method,NCC, which is incorporated with a redundancy optimization processing strategy,realizing more precise in the anonymous area and accurately guaranteeing the related degree of privacy. Adopting NCC verification experiments reflects varied advantages as bellow: (1) By reducing 80% searching time, NCC highly improved searching process. (2) The anonymous area produced in NCC not only meet users' anonymous demands, but the direction of the mobility which improves 4 times accuracy of services in comparison with Casper mode.(3) According to optimization strategy, NCC can reach minimum anonymous area index, increasing the rates of anonymous optimization in original algorithm.
基金supported in part by the National Science and Technology Major Project (No. 2012ZX03002001004)the National Natural Science Foundation of China (Nos. 61172090, 61163009, and 61163010)+1 种基金the PhD Programs Foundation of Ministry of Education of China (No. 20120201110013)the Scientific and Technological Project in Shaanxi Province (Nos. 2012K06-30 and 2014JQ8322)
文摘The widespread use of Location-Based Services （LBSs）, which allows untrusted service providers to collect large quantities of information regarding users＇ locations, has raised serious privacy concerns. In response to these issues, a variety of LBS Privacy Protection Mechanisms （LPPMs） have been recently proposed. However, evaluating these LPPMs remains problematic because of the absence of a generic adversarial model for most existing privacy metrics. In particular, the relationships between these metrics have not been examined in depth under a common adversarial model, leading to a possible selection of the inappropriate metric, which runs the risk of wrongly evaluating LPPMs. In this paper, we address these issues by proposing a privacy quantification model, which is based on Bayes conditional privacy, to specify a general adversarial model. This model employs a general definition of conditional privacy regarding the adversary＇s estimation error to compare the different LBS privacy metrics. Moreover, we present a theoretical analysis for specifying how to connect our metric with other popular LBS privacy metrics. We show that our privacy quantification model permits interpretation and comparison of various popular LBS privacy metrics under a common perspective. Our results contribute to a better understanding of how privacy properties can be measured, as well as to the better selection of the most appropriate metric for any given LBS application.
基金the Centre for Spatial Data Infrastructures and Land Administration and the Department of Infrastructure Engineering at the University of Melbournethe University of Melbourne itselfthe Natural Sciences and Engineering Research Council of Canada for their support of the research conducted for this paper.
文摘The authors compare key elements of the emerging field of Indoor Location-Based Services(Indoor LBS)to those currently found in spatial data infrastructure(SDI)programs.After a brief review of SDIs and Location-Based Services,the corresponding drivers,characteristics and emerging issues within the field of Indoor LBS are introduced and discussed.A comparative framework relates the two in terms of the criteria‘People’,‘Data’,‘Technologies’,‘Standards’and‘Policies/Institutional Arrangements’.After highlighting key similarities and differences,the authors suggested three areas–definition of common framework datasets in Indoor LBS,more effective use of volunteered geographic information by SDI programs and development of appropriate privacy policies by both communities–that may benefit from sharing‘lessons learned’.
基金supported by the National Natural Science Foundation of China(Grant No.62172350)the Fundamental Research Funds for the Central Universities(No.21621028)the Innovation Project of GUET Graduate Education(No.2022YCXS083).
文摘Since smartphones embedded with positioning systems and digital maps are widely used,location-based services(LBSs)are rapidly growing in popularity and providing unprecedented convenience in people’s daily lives;however,they also cause great concern about privacy leakage.In particular,location queries can be used to infer users’sensitive private information,such as home addresses,places of work and appointment locations.Hence,many schemes providing query anonymity have been proposed,but they typically ignore the fact that an adversary can infer real locations from the correlations between consecutive locations in a continuous LBS.To address this challenge,a novel dual privacy-preserving scheme(DPPS)is proposed that includes two privacy protection mechanisms.First,to prevent privacy disclosure caused by correlations between locations,a correlation model is proposed based on a hidden Markov model(HMM)to simulate users’mobility and the adversary’s prediction probability.Second,to provide query probability anonymity of each single location,an advanced k-anonymity algorithm is proposed to construct cloaking regions,in which realistic and indistinguishable dummy locations are generated.To validate the effectiveness and efficiency of DPPS,theoretical analysis and experimental verification are further performed on a real-life dataset published by Microsoft,i.e.,GeoLife dataset.
文摘A novel testing framework for location based services is introduced. In particular, the paper showcases a novel architecture for such a framework. The implementation of the framework illustrates both the functionality and the feasibility of the framework proposed and the utility of the architecture. The new framework is evaluated through comparison to several other methodologies currently available for the testing of location-based applications. A case study is presented in which the testing framework was applied to a typical mobile service tracking system. It is concluded that the proposed testing framework achieves the best coverage of the entire location based service testing problem of the currently available methodologies; being equipped to test the widest array of application attributes and allowing for the automation of testing activities.
基金the Aragon regional government(project GCP-2016-0035-00,program PDR co-financed by FEDER from EU)the Spanish national government(project RTC-2016-4790-2,program Retos Colaboración).
文摘n the current world,it is easy to listen that everybody and everything is connected.Over this connected world,the concept of location-based services has grown in order to provide digital services in everyplace and at every time.Nevertheless,this is not 100%true because the connection is not guaranteed for many people and in many places.These are the Degraded Communications Environments(DCE),environments where the availability of high-speed communications is not guaranteed in at least the 75%of the time.This paper works over the experience of a previous work in developing light protocols that do not need broadband for communication.This work provides an extension of these protocols for the inclusion of mobile devices as elements of the communication process and a set of libraries to allow the development of applications in DCE.The work done has involved the development of two frameworks:an Android framework that makes the incorporation of Android devices easier and a server-based framework that provides the server side for the development of the referred applications.A use case that uses these two frameworks has been developed.Finally,all technology developed is available throw a public Git repository.
文摘Saud Khan,a Pakistani physician,collected his work and residence permits at the Yangpu Government Service Centre in Danzhou City,Hainan Province,on 18 December 2025.Khan had arrived in Hainan three months earlier to participate in a medical training programme at Hainan Western Central Hospital.By the time the programme concluded,he had made up his mind to stay and broaden his professional experience and long-term career prospects in Hainan.
基金supported by the National Key Research and Development Program of China under grant 2022YFF0902701the National Natural Science Foundation of China under grant U21A20468,61972043,61921003+1 种基金Zhejiang Lab under grant 2021PD0AB 02the Fundamental Research Funds for the Central Universities under grant 2020XD-A07-1.
文摘Ensuring an information fabric safe is critical and mandatory.For its related Internet of Things(IoT)service system running on the open Internet,existing host-based monitoring methods may fail due to only inspecting software,and the physical system may not be able to be protected.In this paper,a nonintrusive virtual machine(VM)-based runtime protection framework is provided to protect the physical system with the isolated IoT services as a controlling means.Compared with existing solutions,the framework gets inconsistent and untrusted observation knowledge from multiple observation sources,and enforces property policies concurrently and incrementally in a competing-game way to avoid compositional problems.In addition,the monitoring is implemented without any modification to the protected system.Experiments are conducted to validate the proposed techniques.
文摘Identifying the community structure of complex networks is crucial to extracting insights and understanding network properties.Although several community detection methods have been proposed,many are unsuitable for social networks due to significant limitations.Specifically,most approaches depend mainly on user-user structural links while overlooking service-centric,semantic,and multi-attribute drivers of community formation,and they also lack flexible filtering mechanisms for large-scale,service-oriented settings.Our proposed approach,called community discovery-based service(CDBS),leverages user profiles and their interactions with consulted web services.The method introduces a novel similarity measure,global similarity interaction profile(GSIP),which goes beyond typical similarity measures by unifying user and service profiles for all attributes types into a coherent representation,thereby clarifying its novelty and contribution.It applies multiple filtering criteria related to user attributes,accessed services,and interaction patterns.Experimental comparisons against Louvain,Hierarchical Agglomerative Clustering,Label Propagation and Infomap show that CDBS reveals the higher performance as it achieves 0.74 modularity,0.13 conductance,0.77 coverage,and significantly fast response time of 9.8 s,even with 10,000 users and 400 services.Moreover,community discoverybased service consistently detects a larger number of communities with distinct topics of interest,underscoring its capacity to generate detailed and efficient structures in complex networks.These results confirm both the efficiency and effectiveness of the proposed method.Beyond controlled evaluation,communities discovery based service is applicable to targeted recommendations,group-oriented marketing,access control,and service personalization,where communities are shaped not only by user links but also by service engagement.
文摘Objective:To systematically summarize and evaluate the evidence on discharge preparation services for patients undergoing total knee arthroplasty,providing an evidence-based foundation for developing scientific and standardized discharge preparation intervention programs in clinical practice.Methods:Following the“5S”evidence model,literature such as guidelines,expert consensuses,evidence summaries and randomized controlled trials related to discharge preparation services for total knee arthroplasty patients were retrieved from relevant websites and databases,both domestic and international,from database inception to August 31,2025.Two researchers independently screened the literature,conducted quality appraisals,and extracted and synthesized the evidence.Results:A total of 15 articles were included,comprising 3 guidelines,4 expert consensuses,3 evidence summaries,3 systematic reviews and 2 randomized controlled trials.Ultimately,23 pieces of evidence were summarized across five aspects.Conclusion:This study synthesizes the evidence on discharge preparation services for patients undergoing total knee arthroplasty.It is recommended that healthcare professionals apply this evidence in clinical practice,considering specific circumstances and patient needs.
基金supported by the National Natural Science Foundation of China (Nos.61370192,61432015,61428203,and 61572347)the US National Science Foundation (Nos.CNS-1319915 and CNS-1343355)
文摘Location privacy has been a serious concern for mobile users who use location-based services provided by third-party providers via mobile networks. Recently, there have been tremendous efforts on developing new anonymity or obfuscation techniques to protect location privacy of mobile users. Though effective in certain scenarios, these existing techniques usually assume that a user has a constant privacy requirement along spatial and/or temporal dimensions, which may be not true in real-life scenarios. In this paper, we introduce a new location privacy problem： Location-aware Location Privacy Protection （L2P2） problem, where users can define dynamic and diverse privacy requirements for different locations. The goal of the L2P2 problem is to find the smallest cloaking area for each location request so that diverse privacy requirements over spatial and/or temporal dimensions are satisfied for each user. In this paper, we formalize two versions of the L2P2 problem, and propose several efficient heuristics to provide such location-aware location privacy protection for mobile users. Through extensive simulations over large synthetic and real-life datasets, we confirm the effectiveness and efficiency of the proposed L2P2 algorithms.
基金funded by the National Natural Science Foundation of China(42377326 and 42201267)National Research-Development Support Plan Projects of China(Grant No.2017YFC05054)the Fujian Provincial Water Resources Department Science and Technology Project(MSK202308)。
文摘The Guangdong,Jiangxi and Fujian(GJF)provinces,located in the subtropical region of southeastern China,is one of the national key regions for soil erosion control and ecological restoration.This region is characterized by extensive red soil development and high rainfall erosivity,making it a representative landscape for exploring the interactions between land use change(LUC)and ecosystem services(ES).Despite the recognized importance of ES in hilly regions,comprehensive assessing the impacts of LUC on ES remain limited.This study investigates five key ES:water yield,soil conservation,carbon conservation,food supply,and habitat quality in GJF region from 2000 to 2020.By applying the InVEST model and the Geodetector method,we assessed the trade-offs,synergies,and transitions among ES,identified the natural and social drivers of ES dynamics,and quantified the contribution of LUC to ES changes using the ecosystem service contribution index.The results showed that cropland and woodland were the dominant land use types.Ecological restoration efforts positively influenced ES,with synergies intensifying and trade-offs diminishing over time.Land use conversions,particularly among woodland,grassland,and cropland,exerted significant impacts on ES.In particular,the conversion of woodland to other land uses had markedly negative effects on soil conservation,carbon conservation,and habitat quality.Forest cover was identified as a major driver of ES dynamics.These findings highlight the importance of maintaining and expanding forest and grassland cover,strengthening red soil conservation,and optimizing land use structure to achieve coordinated ecological protection and socioeconomic development in the subtropical hilly regions of southern China.
基金This work was supported by the National Science Foundation under Grant CNS-2007995 and Grant CNS-2008145。
文摘Ubiquitous information exchange is achieved among connected vehicles through the increasingly smart environment.The concept of conventional vehicular ad hoc network is gradually transformed into the Internet of vehicles(IoV).Meanwhile,more and more locationbased services(LBSs)are created to provide convenience for drivers.However,the frequently updated location information sent to the LBS server also puts user location privacy at risk.Thus,preserve user location privacy while allowing vehicles to have high-quality LBSs is a critical issue.Many solutions have been proposed in the literature to preserve location privacy.However,most of them cannot provide real-time LBS with accurate location updates.In this paper,we propose a novel location privacy-preserving scheme,which allows vehicles to send accurate real-time location information to the LBS server while preventing being tracked by attackers.In the proposed scheme,a vehicle utilizes the location information of selected shadow vehicles,whose route diverge from the requester,to generate multiple virtual trajectories to the LBS server so as to mislead attackers.Simulation results show that our proposed scheme achieves a high privacy-preserving level and outperforms other state-of-the-art schemes in terms of location entropy and tracking success ratio.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.61532021,U1811264 and U1501252).
文摘1 Introduction and main contributions Location-based services are springing up around us,while leakages of users'privacy are inevitable during services.Even worse,adversaries may analyze intercepted service data,and extract more privacy like health and property.Therefore,privacy preservation is an indispensable guarantee on LBS security.Among the previous approaches to privacy preservation,k-anonymity-based ones have drawn much research attention[1-3].However,some privacy concern will be aroused if these schemes are adopted directly.For instance,Ut issues a query"Find the nearest hotel around me"in such an area as Fig.1(privacy profile k=4).DLS algorithm[2]constructs anonymity set A because these four cells have similar probabilities of being queried in the past.However,experienced adversaries can exclude some cells if they have learned rich contextual knowledge(side information)from historical data,such as features of each cell and LBS users.
