为了提升信道状态信息(channel state information,CSI)指纹室内定位的性能,提出了一种改进MixNet的CSI图像指纹室内定位方法.在离线阶段,通过选择定位参考点(reference point,RP)处信号强度指示(received signal strength indication,R...为了提升信道状态信息(channel state information,CSI)指纹室内定位的性能,提出了一种改进MixNet的CSI图像指纹室内定位方法.在离线阶段,通过选择定位参考点(reference point,RP)处信号强度指示(received signal strength indication,RSSI)最强的3个接入点(access point,AP),提取其CSI数据并转换为图像;然后利用改进的MixNet模型对图像进行训练并保存模型.其中改进的MixNet引入了坐标注意力(coordinate attention,CA)和残差连接.首先,将MixNet-s中的SE(squeeze-and-excitation)注意力替换为CA,以增强网络的信息表示能力并更精确地获取CSI图像指纹特征.其次,根据MixNet-s模型的特点构建残差连接,以增强网络的表示能力并防止过拟合.最后,通过减小网络深度确保所有网络层得到充分训练;在线阶段,采集目标设备的CSI数据并转换为图像,输入已训练好的改进MixNet模型(命名为MixNet-CA);最后利用加权质心算法根据模型输出的概率值估计目标设备的最终位置.提出方法在室内环境中进行了验证,达到了0.3620 m的平均定位误差.展开更多
Exactly capturing three dimensional (3D) motion i nf ormation of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision s yst...Exactly capturing three dimensional (3D) motion i nf ormation of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision s ystem and a method for determining 3D motion parameters of an object from binocu lar sequence images are introduced. The main steps include camera calibration, t he matching of motion and stereo images, 3D feature point correspondences and re solving the motion parameters. Finally, the experimental results of acquiring th e motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned meth od are presented.展开更多
Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved ...Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved to be effective as commanding and dispatching system. Monitoring system for underground equipment based on panoramic images was effectively combined with real-time sensor data and static panoramic images of underground surrounding, which not only realizes real-time status monitoring for underground equipment, but also gets a direct scene for underground surrounding. B/S mode was applied in the monitoring system and this is convenient for users to monitor the equipment. Meantime, it can reduce the waste of the data resource.展开更多
The meta-instable state(MIS)is the final stage before fault instability during stick-slip movement.Thus,identification of MIS is of great significance for assessing earthquake hazard in fault zones.A rock sample with ...The meta-instable state(MIS)is the final stage before fault instability during stick-slip movement.Thus,identification of MIS is of great significance for assessing earthquake hazard in fault zones.A rock sample with a precut planar fault was loaded on a horizontally biaxial servo-controlled press machine to create stick-slip conditions.Digital images of the sample surface were taken by a high-speed camera at a rate of 1000 frames per second during the stick-slip motion and processed using a 2D digital image correlation method to obtain the displacement field.We define a synergism coefficient that describes the relative dispersion of the accumulative fault slip.The results reveal that:(1)a local pre-slip area spreads very slowly along the fault before the MIS develops.It extends at a higher but still slow speed during meta-instable state I(MIS-I).During the final^1.5%of MIS,in meta-instable state II(MIS-II),the local pre-slip area first extends at a speed of^0.9 m/s,and then expands out of the observed image area at a very high speed.These results indicate that the local pre-slip area transforms from a state of quasi-static extension in MIS-I to quasi-dynamic extension in MIS-II.(2)The synergism coefficient of the fault slip decreases to half of its original value in MIS-I and to a quarter of its original value in MIS-II.This continuous decrease of synergism coefficient indicates that the strengthening of fault slip synergism is a characteristic of MIS.(3)Furthermore,the unstable sliding stage includes three sliding processes:initial-,fast-,and adjusted-sliding.There are two pauses between the three sliding processes.展开更多
文摘为了提升信道状态信息(channel state information,CSI)指纹室内定位的性能,提出了一种改进MixNet的CSI图像指纹室内定位方法.在离线阶段,通过选择定位参考点(reference point,RP)处信号强度指示(received signal strength indication,RSSI)最强的3个接入点(access point,AP),提取其CSI数据并转换为图像;然后利用改进的MixNet模型对图像进行训练并保存模型.其中改进的MixNet引入了坐标注意力(coordinate attention,CA)和残差连接.首先,将MixNet-s中的SE(squeeze-and-excitation)注意力替换为CA,以增强网络的信息表示能力并更精确地获取CSI图像指纹特征.其次,根据MixNet-s模型的特点构建残差连接,以增强网络的表示能力并防止过拟合.最后,通过减小网络深度确保所有网络层得到充分训练;在线阶段,采集目标设备的CSI数据并转换为图像,输入已训练好的改进MixNet模型(命名为MixNet-CA);最后利用加权质心算法根据模型输出的概率值估计目标设备的最终位置.提出方法在室内环境中进行了验证,达到了0.3620 m的平均定位误差.
文摘Exactly capturing three dimensional (3D) motion i nf ormation of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision s ystem and a method for determining 3D motion parameters of an object from binocu lar sequence images are introduced. The main steps include camera calibration, t he matching of motion and stereo images, 3D feature point correspondences and re solving the motion parameters. Finally, the experimental results of acquiring th e motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned meth od are presented.
基金Supported by the National Natural Science Foundation of China （51075029）
文摘Complex terrain and working equipment in coal mine underground need a way to ensure coal mine safety. In this paper, the way to monitor the real-time status of underground equipment was put forward, and it was proved to be effective as commanding and dispatching system. Monitoring system for underground equipment based on panoramic images was effectively combined with real-time sensor data and static panoramic images of underground surrounding, which not only realizes real-time status monitoring for underground equipment, but also gets a direct scene for underground surrounding. B/S mode was applied in the monitoring system and this is convenient for users to monitor the equipment. Meantime, it can reduce the waste of the data resource.
基金supported by the National Natural Science Foundation of China(Grant No.41172180)Basic Research Funds from the Institute of Geology,China Earthquake Administration(Grant No.IGCEA1203)
文摘The meta-instable state(MIS)is the final stage before fault instability during stick-slip movement.Thus,identification of MIS is of great significance for assessing earthquake hazard in fault zones.A rock sample with a precut planar fault was loaded on a horizontally biaxial servo-controlled press machine to create stick-slip conditions.Digital images of the sample surface were taken by a high-speed camera at a rate of 1000 frames per second during the stick-slip motion and processed using a 2D digital image correlation method to obtain the displacement field.We define a synergism coefficient that describes the relative dispersion of the accumulative fault slip.The results reveal that:(1)a local pre-slip area spreads very slowly along the fault before the MIS develops.It extends at a higher but still slow speed during meta-instable state I(MIS-I).During the final^1.5%of MIS,in meta-instable state II(MIS-II),the local pre-slip area first extends at a speed of^0.9 m/s,and then expands out of the observed image area at a very high speed.These results indicate that the local pre-slip area transforms from a state of quasi-static extension in MIS-I to quasi-dynamic extension in MIS-II.(2)The synergism coefficient of the fault slip decreases to half of its original value in MIS-I and to a quarter of its original value in MIS-II.This continuous decrease of synergism coefficient indicates that the strengthening of fault slip synergism is a characteristic of MIS.(3)Furthermore,the unstable sliding stage includes three sliding processes:initial-,fast-,and adjusted-sliding.There are two pauses between the three sliding processes.
