自射频消融(Radiofrequency Current Abltion,RFCA)根治预激综合征(Wolff-Parkinson-White,WPW)合并室上性心动过速(SVT)开展以来,体表心电图与旁道(Accessery Pathways,AP)定位的相关关系有多篇报道,尤其是对左右游离壁AP定位准确率高...自射频消融(Radiofrequency Current Abltion,RFCA)根治预激综合征(Wolff-Parkinson-White,WPW)合并室上性心动过速(SVT)开展以来,体表心电图与旁道(Accessery Pathways,AP)定位的相关关系有多篇报道,尤其是对左右游离壁AP定位准确率高,左侧游离壁AP定位准确率可接近心内膜标测水平达98％,右游离壁AP定位准确率不及左侧游离壁高仅达92％,但左右间隔AP体表心电图定位鉴别诊断难度大,定位准确率低。根据Rodriguez和Epsteinc研究结果,结合我们临床研究现综述如下。展开更多
无线局域网(WLAN)中可以对无线接入点(Access Point,AP)进行定位。该文提出一种基于概率密度的AP定位算法(Probability Density algorithm for Access Point Localization,PDAPL)。首先对实验区域进行分区;然后根据定向天线在不同位置...无线局域网(WLAN)中可以对无线接入点(Access Point,AP)进行定位。该文提出一种基于概率密度的AP定位算法(Probability Density algorithm for Access Point Localization,PDAPL)。首先对实验区域进行分区;然后根据定向天线在不同位置和不同角度收到的信号强度,计算AP落在各区域的概率,形成与密度有关的概率统计表;最后对AP的位置进行评估。实验结果表明,该文提出的算法采集数据少,只需在少量点和少量角度采集信号就可以得到较高的定位精度。与Driveby Loc,Distance和Ao A相比,得到相同的定位精度PDAPL所需要的测量点和测量角度只是Driveby Loc的一半左右,比Distance和Ao A所需要的更少;测量点和测量角度数量相同时,PDAPL的定位精度相对于Driveby Loc提升了50%左右。展开更多
Recent rapid rise of indoor location based services for smartphones has further increased the importance of precise localization of Wi-Fi Access Point(AP).However,most existing AP localization algorithms either exhibi...Recent rapid rise of indoor location based services for smartphones has further increased the importance of precise localization of Wi-Fi Access Point(AP).However,most existing AP localization algorithms either exhibit high errors or need specialized hardware in practical scenarios.In this paper,we propose a novel RSSI gradient-based AP localization algorithm.It consists of the following three major steps:firstly,it uses the local received signal strength variations to estimate the direction(minus gradient) of AP,then employs a direction clustering method to identify and filter measurement outliers,and finally adopts triangulation method to localize AP with the selected gradient directions.Experimental results demonstrate that the average localization error of our proposed algorithm is less than 2meters,far outperforming that of the weighted centroid approach.展开更多
文摘自射频消融(Radiofrequency Current Abltion,RFCA)根治预激综合征(Wolff-Parkinson-White,WPW)合并室上性心动过速(SVT)开展以来,体表心电图与旁道(Accessery Pathways,AP)定位的相关关系有多篇报道,尤其是对左右游离壁AP定位准确率高,左侧游离壁AP定位准确率可接近心内膜标测水平达98％,右游离壁AP定位准确率不及左侧游离壁高仅达92％,但左右间隔AP体表心电图定位鉴别诊断难度大,定位准确率低。根据Rodriguez和Epsteinc研究结果,结合我们临床研究现综述如下。
文摘无线局域网(WLAN)中可以对无线接入点(Access Point,AP)进行定位。该文提出一种基于概率密度的AP定位算法(Probability Density algorithm for Access Point Localization,PDAPL)。首先对实验区域进行分区;然后根据定向天线在不同位置和不同角度收到的信号强度,计算AP落在各区域的概率,形成与密度有关的概率统计表;最后对AP的位置进行评估。实验结果表明,该文提出的算法采集数据少,只需在少量点和少量角度采集信号就可以得到较高的定位精度。与Driveby Loc,Distance和Ao A相比,得到相同的定位精度PDAPL所需要的测量点和测量角度只是Driveby Loc的一半左右,比Distance和Ao A所需要的更少;测量点和测量角度数量相同时,PDAPL的定位精度相对于Driveby Loc提升了50%左右。
基金This work was supported in part by the National Natural Science Foundation of China，the Major Projects of Ministry of Industry and Information Technology，the National High Technology Research and Development Program of China
文摘Recent rapid rise of indoor location based services for smartphones has further increased the importance of precise localization of Wi-Fi Access Point(AP).However,most existing AP localization algorithms either exhibit high errors or need specialized hardware in practical scenarios.In this paper,we propose a novel RSSI gradient-based AP localization algorithm.It consists of the following three major steps:firstly,it uses the local received signal strength variations to estimate the direction(minus gradient) of AP,then employs a direction clustering method to identify and filter measurement outliers,and finally adopts triangulation method to localize AP with the selected gradient directions.Experimental results demonstrate that the average localization error of our proposed algorithm is less than 2meters,far outperforming that of the weighted centroid approach.
