Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phas...Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phase variations of the received signal across the whole array are nonnegligible in the near-field region,and the channel model mismatch,which will decrease the estimation accuracy,must be considered.In this paper,the lower bound(LB)of the estimated parameter is studied and the impacts of the distance and signal-tonoise ratio(SNR)on LB are then evaluated.Moreover,the impacts of the array scale on LB and spectral efficiency(SE)are also studied.Simulation results verify that even in extremely large-scale array systems with infinite SNR,channel model mismatch can still limit estimation accuracy.However,this impact decreases with increasing distance.展开更多
As English and Chinese belong to different language families,the left and right branching structures in the two languages are both similar and different.Generally speaking,Chinese has a predominance of left-branching ...As English and Chinese belong to different language families,the left and right branching structures in the two languages are both similar and different.Generally speaking,Chinese has a predominance of left-branching structures and English has a predominance of right-branching structures.That is to say,Chinese is used to using left branches in its expressions,while English is used to using right branches in its expressions.展开更多
为满足日益增长的高品质、多样化、个性化旅游需求,采用基于位置的服务(Location Based Services,LBS),结合用户行为分析和智能算法处理,设计旅游路线推荐系统。该系统由个性化路线推荐模块、消息推送模块、用户管理模块、人工智能模块...为满足日益增长的高品质、多样化、个性化旅游需求,采用基于位置的服务(Location Based Services,LBS),结合用户行为分析和智能算法处理,设计旅游路线推荐系统。该系统由个性化路线推荐模块、消息推送模块、用户管理模块、人工智能模块等构成。系统性能测试结果表明,该推荐系统能显著提高旅游规划效率和用户满意度,可为旅游行业智慧化服务模式发展提供技术支持。展开更多
Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS(Location Based Service) is arising. To provide location based service, tracking data should have been s...Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS(Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location, because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.展开更多
随着移动互联网和物联网技术的发展,基于位置服务(LBS)的智能供应链系统越来越受到关注。传统供应链管理主要依靠人工管理和信息系统处理,缺少实时感知、快速响应和高效决策等功能,难以满足目前市场的个性化、高效率和低成本需求。基于...随着移动互联网和物联网技术的发展,基于位置服务(LBS)的智能供应链系统越来越受到关注。传统供应链管理主要依靠人工管理和信息系统处理,缺少实时感知、快速响应和高效决策等功能,难以满足目前市场的个性化、高效率和低成本需求。基于LBS技术的智能供应链系统可以实现对产品、仓库、运输和客户等各个环节的实时监测和精细管理,提高供应链的可视化程度、透明度和敏捷性。本文采用SQLITE进行数据保存,采用北斗导航系统进行车辆位置定位,采用OCR(Optical Character Recognition)进行证件识别,实现任务管理、监控管理、行驶区域管理以及车辆管理等功能,可以快速地定位和监控车辆,提高运输可靠性。展开更多
在科学技术创新发展的进程中,基于位置服务(Location Based Services,LBS)也在逐步升级及优化,并在娱乐、旅游及社交等多个方面发挥作用,极大地提高了日常生活的便捷性,同时推动着电子商务的规模化发展。基于LBS的特性,移动互联网是不...在科学技术创新发展的进程中,基于位置服务(Location Based Services,LBS)也在逐步升级及优化,并在娱乐、旅游及社交等多个方面发挥作用,极大地提高了日常生活的便捷性,同时推动着电子商务的规模化发展。基于LBS的特性,移动互联网是不可或缺的一部分,传统互联网营销模式相对落后,客流量的持续增加具有较大难度,需基于LBS探索更为可行的O2O精准营销途径,有效扩大客户范围,增加客户黏性。本文就以LBS的未知服务为基准,对其在O2O电子商务中的精准营销实现方式进行了深入研究,为商业模式的创新发展提供更多思路及参考。展开更多
k-匿名机制是LBS(location based service)中保证查询隐私性的重要手段.已有文献指出,现有的k-匿名机制不能有效保护连续性查询的隐私性.提出一种连续查询发送模型,该模型融合了查询发送时间的间隔模型和连续性模型,针对此模型下的两种k...k-匿名机制是LBS(location based service)中保证查询隐私性的重要手段.已有文献指出,现有的k-匿名机制不能有效保护连续性查询的隐私性.提出一种连续查询发送模型,该模型融合了查询发送时间的间隔模型和连续性模型,针对此模型下的两种k-匿名算法Clique Cloaking和Non-clique Cloaking,分别提出了一种连续查询攻击算法.在此攻击算法下,匿名集的势不再适合作为查询匿名性的度量,因此提出一种基于熵理论的度量方式AD(anonymityd egree).实验结果表明,对连续性很强的查询,攻击算法重识别用户身份的成功率极高;AD比匿名集的势更能反映查询的匿名性.展开更多
基金supported in part by the National Natural Science Founda⁃tion of China(NSFC)under Grant Nos.62301148,62341107,and 62261160576by the Natural Science Foundation of Jiangsu Prov⁃ince under Grant No.BK20230824in part by the Key Technologies R&D Program of Jiangsu(Prospective and Key Technologies for Indus⁃try)under Grant Nos.BE2023022 and BE2023022-1.
文摘Extremely large-scale hybrid reconfigurable intelligence surface(XL-HRIS),an improved version of the RIS,can receive the incident signal and enhance communication performance.However,as the RIS size increases,the phase variations of the received signal across the whole array are nonnegligible in the near-field region,and the channel model mismatch,which will decrease the estimation accuracy,must be considered.In this paper,the lower bound(LB)of the estimated parameter is studied and the impacts of the distance and signal-tonoise ratio(SNR)on LB are then evaluated.Moreover,the impacts of the array scale on LB and spectral efficiency(SE)are also studied.Simulation results verify that even in extremely large-scale array systems with infinite SNR,channel model mismatch can still limit estimation accuracy.However,this impact decreases with increasing distance.
基金sponsored by the teaching program“English Grammar” (No.209/1541801009).
文摘As English and Chinese belong to different language families,the left and right branching structures in the two languages are both similar and different.Generally speaking,Chinese has a predominance of left-branching structures and English has a predominance of right-branching structures.That is to say,Chinese is used to using left branches in its expressions,while English is used to using right branches in its expressions.
文摘为满足日益增长的高品质、多样化、个性化旅游需求,采用基于位置的服务(Location Based Services,LBS),结合用户行为分析和智能算法处理,设计旅游路线推荐系统。该系统由个性化路线推荐模块、消息推送模块、用户管理模块、人工智能模块等构成。系统性能测试结果表明,该推荐系统能显著提高旅游规划效率和用户满意度,可为旅游行业智慧化服务模式发展提供技术支持。
文摘Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS(Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location, because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.
文摘随着移动互联网和物联网技术的发展,基于位置服务(LBS)的智能供应链系统越来越受到关注。传统供应链管理主要依靠人工管理和信息系统处理,缺少实时感知、快速响应和高效决策等功能,难以满足目前市场的个性化、高效率和低成本需求。基于LBS技术的智能供应链系统可以实现对产品、仓库、运输和客户等各个环节的实时监测和精细管理,提高供应链的可视化程度、透明度和敏捷性。本文采用SQLITE进行数据保存,采用北斗导航系统进行车辆位置定位,采用OCR(Optical Character Recognition)进行证件识别,实现任务管理、监控管理、行驶区域管理以及车辆管理等功能,可以快速地定位和监控车辆,提高运输可靠性。
文摘在科学技术创新发展的进程中,基于位置服务(Location Based Services,LBS)也在逐步升级及优化,并在娱乐、旅游及社交等多个方面发挥作用,极大地提高了日常生活的便捷性,同时推动着电子商务的规模化发展。基于LBS的特性,移动互联网是不可或缺的一部分,传统互联网营销模式相对落后,客流量的持续增加具有较大难度,需基于LBS探索更为可行的O2O精准营销途径,有效扩大客户范围,增加客户黏性。本文就以LBS的未知服务为基准,对其在O2O电子商务中的精准营销实现方式进行了深入研究,为商业模式的创新发展提供更多思路及参考。
