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Location Privacy in Device-Dependent Location-Based Services:Challenges and Solution 被引量:1
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作者 Yuhang Wang Yanbin Sun +4 位作者 Shen Su Zhihong Tian Mohan Li Jing Qiu Xianzhi Wang 《Computers, Materials & Continua》 SCIE EI 2019年第6期983-993,共11页
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
关键词 Location privacy device-dependent location-based service location-based service credit system location privacy preserving mechanism shared bicycle
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User location privacy protection mechanism for location-based services 被引量:6
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作者 Yan He Jiageng Chen 《Digital Communications and Networks》 SCIE CSCD 2021年第2期264-276,共13页
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
关键词 Internet of things location-based services Location privacy Privacy protection mechanism CONFIDENTIALITY
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Design and implementation of user information sharing system using location-based services for social network services
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作者 Donsu Lee Junghoon Shin Sangjun Lee 《Journal of Measurement Science and Instrumentation》 CAS 2012年第2期169-172,共4页
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
关键词 android OS social network service(SNS) location-based service(LBS) Google maps TWITTER Open API
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Location and Its Semantics in Location-Based Services 被引量:1
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作者 ZHAO Dongqing LUE Zhiping ZHANG Xiguang 《Geo-Spatial Information Science》 2007年第2期145-150,共6页
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
关键词 personalized preference services LOCATION SEMANTICS ONTOLOGY
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Privacy Preserving Scheme for Location-Based Services 被引量:1
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作者 Youssef Gahi Mouhcine Guennoun +1 位作者 Zouhair Guennoun Khalil El-Khatib 《Journal of Information Security》 2012年第2期105-112,共8页
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
关键词 PRIVACY LOCATION BASED serviceS Homomorphic ENCRYPTION
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The NCC: An Improved Anonymous Method for Location-Based Services Based on Casper
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作者 Wenqi Liu Jie Feng Guangwei Wang 《国际计算机前沿大会会议论文集》 2017年第2期129-131,共3页
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
关键词 PRIVACY protection CASPER CLOAK location-based services REDUNDANCY optimization
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DPPS: A novel dual privacy-preserving scheme for enhancing query privacy in continuous location-based services 被引量:1
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作者 Long LI Jianbo HUANG +3 位作者 Liang CHANG Jian WENG Jia CHEN Jingjing LI 《Frontiers of Computer Science》 SCIE EI CSCD 2023年第5期197-205,共9页
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
关键词 location-based services PRIVACY-PRESERVING hidden Markov model K-ANONYMITY query probability
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Providing Location-Aware Location Privacy Protection for Mobile Location-Based Services 被引量:6
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作者 Yu Wang Dingbang Xu Fan Li 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2016年第3期243-259,共17页
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
关键词 location privacy K-ANONYMITY cloaking algorithm location-based service mobile networks
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Privacy Quantification Model Based on the Bayes Conditional Risk in Location-Based Services 被引量:6
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作者 Xuejun Zhang Xiaolin Gui +2 位作者 Feng Tian Si Yu Jian An 《Tsinghua Science and Technology》 SCIE EI CAS 2014年第5期452-462,共11页
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
关键词 location-based services Bayes decision estimator privacy metric adversarial mode
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Expanding the SDI environment:comparing current spatial data infrastructure with emerging indoor location-based services 被引量:1
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作者 David J.Coleman Abbas Rajabifard Kris W.Kolodziej 《International Journal of Digital Earth》 SCIE EI CSCD 2016年第6期629-647,共19页
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
关键词 Spatial data infrastructure location-based services INDOOR POSITIONING mapping GEOSPATIAL
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A Scalable Testing Framework for Location-Based Services 被引量:1
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作者 Jiang Yu Andrew Tappenden +1 位作者 James Miller Michael Smith 《Journal of Computer Science & Technology》 SCIE EI CSCD 2009年第2期386-404,共19页
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
关键词 location based applications location-based services M-COMMERCE software testing
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The digital‘connected’earth:open technology for providing location-based services on degraded communication environments
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作者 Ramón Piedrafita Rubén Béjar +2 位作者 Rubén Blasco Alvaro Marco F.Javier Zarazaga-Soria Aragón 《International Journal of Digital Earth》 SCIE EI 2018年第8期761-782,共22页
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
关键词 location-based services degraded communications environments open technology
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A Privacy-Preserving Scheme for Location-Based Services in the Internet of Vehicles
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作者 Jiaqi Huang Yi Qian Rose Qingyang Hu 《Journal of Communications and Information Networks》 EI CSCD 2021年第4期385-395,共11页
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
关键词 location privacy location-based service internet of vehicles vehicular networks
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Neural Network-Based State Estimation for Nonlinear Systems With Denial-of-Service Attack Under Try-Once-Discard Protocol
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作者 Xueli Wang Shangwei Zhao +2 位作者 Ming Yang Xin Wang Xiaoming Wu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第10期2182-2184,共3页
Dear Editor,This letter deals with state estimation issues of discrete-time nonlinear systems subject to denial-of-service(DoS)attacks under the try-once-discard(TOD)protocol.More specifically,to reduce the communicat... Dear Editor,This letter deals with state estimation issues of discrete-time nonlinear systems subject to denial-of-service(DoS)attacks under the try-once-discard(TOD)protocol.More specifically,to reduce the communication burden,a TOD protocol with novel update rules on protocol weights is designed for scheduling measurement outputs.In addition,unknown nonlinear functions vulnerable to DoS attacks are considered due to the openness and vulnerability of the network. 展开更多
关键词 service DOS service
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Deep Reinforcement Learning-Based Task Offloading and Service Migrating Policies in Service Caching-Assisted Mobile Edge Computing
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作者 Ke Hongchang Wang Hui +1 位作者 Sun Hongbin Halvin Yang 《China Communications》 SCIE CSCD 2024年第4期88-103,共16页
Emerging mobile edge computing(MEC)is considered a feasible solution for offloading the computation-intensive request tasks generated from mobile wireless equipment(MWE)with limited computational resources and energy.... Emerging mobile edge computing(MEC)is considered a feasible solution for offloading the computation-intensive request tasks generated from mobile wireless equipment(MWE)with limited computational resources and energy.Due to the homogeneity of request tasks from one MWE during a longterm time period,it is vital to predeploy the particular service cachings required by the request tasks at the MEC server.In this paper,we model a service caching-assisted MEC framework that takes into account the constraint on the number of service cachings hosted by each edge server and the migration of request tasks from the current edge server to another edge server with service caching required by tasks.Furthermore,we propose a multiagent deep reinforcement learning-based computation offloading and task migrating decision-making scheme(MBOMS)to minimize the long-term average weighted cost.The proposed MBOMS can learn the near-optimal offloading and migrating decision-making policy by centralized training and decentralized execution.Systematic and comprehensive simulation results reveal that our proposed MBOMS can converge well after training and outperforms the other five baseline algorithms. 展开更多
关键词 deep reinforcement learning mobile edge computing service caching service migrating
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Detection of Real-Time Distributed Denial-of-Service (DDoS) Attacks on Internet of Things (IoT) Networks Using Machine Learning Algorithms
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作者 Zaed Mahdi Nada Abdalhussien +1 位作者 Naba Mahmood Rana Zaki 《Computers, Materials & Continua》 SCIE EI 2024年第8期2139-2159,共21页
The primary concern of modern technology is cyber attacks targeting the Internet of Things.As it is one of the most widely used networks today and vulnerable to attacks.Real-time threats pose with modern cyber attacks... The primary concern of modern technology is cyber attacks targeting the Internet of Things.As it is one of the most widely used networks today and vulnerable to attacks.Real-time threats pose with modern cyber attacks that pose a great danger to the Internet of Things(IoT)networks,as devices can be monitored or service isolated from them and affect users in one way or another.Securing Internet of Things networks is an important matter,as it requires the use of modern technologies and methods,and real and up-to-date data to design and train systems to keep pace with the modernity that attackers use to confront these attacks.One of the most common types of attacks against IoT devices is Distributed Denial-of-Service(DDoS)attacks.Our paper makes a unique contribution that differs from existing studies,in that we use recent data that contains real traffic and real attacks on IoT networks.And a hybrid method for selecting relevant features,And also how to choose highly efficient algorithms.What gives the model a high ability to detect distributed denial-of-service attacks.the model proposed is based on a two-stage process:selecting essential features and constructing a detection model using the K-neighbors algorithm with two classifier algorithms logistic regression and Stochastic Gradient Descent classifier(SGD),combining these classifiers through ensemble machine learning(stacking),and optimizing parameters through Grid Search-CV to enhance system accuracy.Experiments were conducted to evaluate the effectiveness of the proposed model using the CIC-IoT2023 and CIC-DDoS2019 datasets.Performance evaluation demonstrated the potential of our model in robust intrusion detection in IoT networks,achieving an accuracy of 99.965%and a detection time of 0.20 s for the CIC-IoT2023 dataset,and 99.968%accuracy with a detection time of 0.23 s for the CIC-DDoS 2019 dataset.Furthermore,a comparative analysis with recent related works highlighted the superiority of our methodology in intrusion detection,showing improvements in accuracy,recall,and detection time. 展开更多
关键词 DDOS service NETWORKS
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Sharing Smart Services,Jointly Promoting Trade Development
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作者 Zhang Li 《China's Foreign Trade》 2024年第5期49-51,共3页
In 2024,the China International Fair for Trade in Services (hereinafter referred to as CIFTIS) opened in the China National Convention Center and Shougang Park on September 12th.The theme of the CIFTIS this time was&q... In 2024,the China International Fair for Trade in Services (hereinafter referred to as CIFTIS) opened in the China National Convention Center and Shougang Park on September 12th.The theme of the CIFTIS this time was"global services,shared prosperity",which is not only a window for allowing the world to discover the development of China's service trade,but is also a bridge for promoting global cooperation with regards to the service trade.As one of the world-famous service trade events,the CIFTIS has become an important business card allowing China to open up.The CIFTIS has attracted the attention of the whole world and become a bridge for all parties to share development opportunities,promote industrial growth,and strengthen communication. 展开更多
关键词 TRADE serviceS service
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Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China 被引量:1
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作者 Jin Hu HaiBing Ruan +2 位作者 FuQing Huang ShengYang Gu XianKang Dou 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期400-407,共8页
The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G... The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions. 展开更多
关键词 International GNSS service(IGS)Global Ionosphere Maps(GIM) Crustal Movement Observation Network of China(CMONOC) total electron content(TEC) data assessment
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Dynamical distribution of continuous service time model involving non-Maxwellian collision kernel and value functions
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作者 Minfang Zhao Lingting Kong +1 位作者 Miao Liu Shaoyong Lai 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期340-348,共9页
The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of conti... The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of continuous service time,respectively.Using the statistical mechanical and asymptotic limit methods,Fokker–Planck equations are derived from the corresponding Boltzmann-type equations with non-Maxwellian collision kernels.The steady-state solutions of the Fokker–Planck equation are obtained in exact form.Numerical experiments are provided to support our results under different parameters. 展开更多
关键词 kinetic theory service time Fokker-Planck equation value function
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Research progress and future prospects in the service security of key blast furnace equipment
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作者 Yanxiang Liu Kexin Jiao +3 位作者 Jianliang Zhang Cui Wang Lei Zhang Xiaoyue Fan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第10期2121-2135,共15页
The safety and longevity of key blast furnace(BF)equipment determine the stable and low-carbon production of iron.This pa-per presents an analysis of the heat transfer characteristics of these components and the uneve... The safety and longevity of key blast furnace(BF)equipment determine the stable and low-carbon production of iron.This pa-per presents an analysis of the heat transfer characteristics of these components and the uneven distribution of cooling water in parallel pipes based on hydrodynamic principles,discusses the feasible methods for the improvement of BF cooling intensity,and reviews the pre-paration process,performance,and damage characteristics of three key equipment pieces:coolers,tuyeres,and hearth refractories.Fur-thermoere,to attain better control of these critical components under high-temperature working conditions,we propose the application of optimized technologies,such as BF operation and maintenance technology,self-repair technology,and full-lifecycle management techno-logy.Finally,we propose further researches on safety assessments and predictions for key BF equipment under new operating conditions. 展开更多
关键词 blast furnace EQUIPMENT service security blast furnace campaign SELF-REPAIR
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