NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degra...NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites.Because of the characteristics of large band-width,low latency,and high Base Station(BS)density,the fifth-Generation mobile communication(5G)technology has gradually become a trend for positioning in cities while offering traditional communication service.To supply the communication demands of the User Equipment(UE),only one BS is usually considered to establish a connection with the UE during the BS construction.However,the positioning accuracy with a single BS in urban canyons will be significantly reduced.To further improve the positioning accuracy in such extreme scenarios,this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite.In this system,the GNSS receiver is mounted on the 5G BS,and the measurements provided by the receiver are used to form the differential code and complete the position estimation.The positioning mathematical models of the system based on the original code and differential code are derived.Then,the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically.Finally,the positioning performance is investigated by a set of simulation experiments.Numerical results show that under the existing 5G measurement noise and 2 m’s code measurement noise,the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%,which is also about 6%higher than the original code based fusion positioning.Besides,this improvement is not affected by the time synchronization error between the BS and the GNSS satellite.展开更多
营养风险或营养不良在急诊患者中普遍存在,可导致病死风险上升并造成疾病负担加重。但迄今为止,在急诊领域中,对营养风险的关注度明显低于其他专科。2016年多个国际性营养组织提出了全球领导人营养不良倡议(Global Leadership Initiativ...营养风险或营养不良在急诊患者中普遍存在,可导致病死风险上升并造成疾病负担加重。但迄今为止,在急诊领域中,对营养风险的关注度明显低于其他专科。2016年多个国际性营养组织提出了全球领导人营养不良倡议(Global Leadership Initiative on Malnutrition,GLIM)。GLIM自提出以来,发展迅速,已成为进行营养诊断的主要方法学工具。与此同时,疾病诊断相关分组(diagnosis related groups,DRGs)在中国已经快速普及,并成为新一轮医改的重要内容。在DRGs背景下,营养不良的诊断和干预对患者具有重要的临床和经济学意义。本文将基于GLIM标准结合DRGs的时代背景,从急诊患者的营养风险筛查、营养不良诊断、临床经济学效益以及急诊患者营养评估的未来发展方向等多方面的应用与研究进展进行评述,以期为广大急诊医务人员更好的理解急诊患者的营养评估提供借鉴。展开更多
基金supported by the National tural Science Foundation of ChinaNa[grant number 41974038]NaThe tional Key Research and Development Program of China[grant number 2018YFC0809804].
文摘NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites.Because of the characteristics of large band-width,low latency,and high Base Station(BS)density,the fifth-Generation mobile communication(5G)technology has gradually become a trend for positioning in cities while offering traditional communication service.To supply the communication demands of the User Equipment(UE),only one BS is usually considered to establish a connection with the UE during the BS construction.However,the positioning accuracy with a single BS in urban canyons will be significantly reduced.To further improve the positioning accuracy in such extreme scenarios,this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite.In this system,the GNSS receiver is mounted on the 5G BS,and the measurements provided by the receiver are used to form the differential code and complete the position estimation.The positioning mathematical models of the system based on the original code and differential code are derived.Then,the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically.Finally,the positioning performance is investigated by a set of simulation experiments.Numerical results show that under the existing 5G measurement noise and 2 m’s code measurement noise,the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%,which is also about 6%higher than the original code based fusion positioning.Besides,this improvement is not affected by the time synchronization error between the BS and the GNSS satellite.
文摘营养风险或营养不良在急诊患者中普遍存在,可导致病死风险上升并造成疾病负担加重。但迄今为止,在急诊领域中,对营养风险的关注度明显低于其他专科。2016年多个国际性营养组织提出了全球领导人营养不良倡议(Global Leadership Initiative on Malnutrition,GLIM)。GLIM自提出以来,发展迅速,已成为进行营养诊断的主要方法学工具。与此同时,疾病诊断相关分组(diagnosis related groups,DRGs)在中国已经快速普及,并成为新一轮医改的重要内容。在DRGs背景下,营养不良的诊断和干预对患者具有重要的临床和经济学意义。本文将基于GLIM标准结合DRGs的时代背景,从急诊患者的营养风险筛查、营养不良诊断、临床经济学效益以及急诊患者营养评估的未来发展方向等多方面的应用与研究进展进行评述,以期为广大急诊医务人员更好的理解急诊患者的营养评估提供借鉴。
