To solve the ill-posed and accuracy problems experienced by global navigation satellite system (GNSS) computerized ionosphere tomography (CIT), this study proposes the use of the ionospheric profile data of COSMIC-2 a...
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To solve the ill-posed and accuracy problems experienced by global navigation satellite system (GNSS) computerized ionosphere tomography (CIT), this study proposes the use of the ionospheric profile data of COSMIC-2 as the initial scale factor to constrain GNSS data. At present, studies are lacking on long-term data volume statistics and accuracy assessment of COSMIC-2 ionospheric profile products. Therefore, we calculated the data volume statistics and assessed the ionospheric quality of the COSMIC-2 data for the whole year of 2020. We used incoherent scattering radar (ISR) and ionosonde data to evaluate the quality of the COSMIC-2 ionospheric profile data. To verify the accuracy and reliability of the CIT algorithm for COSMIC-2 ionosphere profile-constrained GNSS data, the American region was selected. On the plane, the tomographic results were superimposed and compared with the global ionospheric map (GIM). The root mean square (rms) of the vertical total electron content (VTEC) difference in the six periods was 0.68, 0.97, 0.63, 0.86, 0.76, and 0.82 total electron content unit (TECU), respectively. In the vertical direction, the scale factor that was not involved in the CIT was compared with the ratio of total electron contents (TECs) in each layer to the total TEC. The average difference of the ratio factors in the four periods was 3.72%, 2.79%, 1.80%, 3.05%, 1.99%, and 2.37%, respectively. Finally, an intermediate-level geomagnetic storm that occurred on July 25, 2020, was selected for analysis, and the 3-D ionospheric morphological changes and evolution characteristics of the Australian region during this geomagnetic storm were studied.
Situation awareness has been widely applied in disaster warning, equipment detection, monitoring and other scenarios. Its datafusion and analysis methods have developed in a diversified way. For the health management...
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Situation awareness has been widely applied in disaster warning, equipment detection, monitoring and other scenarios. Its datafusion and analysis methods have developed in a diversified way. For the health management of substation equipment, there is still room for improvement in order to effectively integrate information from multiple sites, analyze the operating status of multiple devices, detect and locate faults, and predict the overall situation. This paper discusses the concept of situation awareness, analyzes its role in the automation and intelligence process of substations, and summarizes the commonly used algorithms for data processing, situation evaluation, and prediction in recent years.
Sensor-less speed estimation of brushed DC motor is preferred for dynamic control and state monitoring. Ripplebased and model-based methods are widely applied for sensor-less speed estimation. This paper firstly offer...
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Sensor-less speed estimation of brushed DC motor is preferred for dynamic control and state monitoring. Ripplebased and model-based methods are widely applied for sensor-less speed estimation. This paper firstly offers a ripple-based technique, analyzes their features and performance, then presents a modified Kalman filter to fuse the ripple-base and model-based results. The two source data are fused through modification of the noise covariance matrices of the conventional Kalman filter. Experimental validates the proposed algorithm. Test shows that the proposed method reduces speed estimation to less 3% and owns roughly 8 times of accuracy comparing with conventional ripple-based and model-based methods. The proposed method is suitable for speed monitoring of industrial applications involving brushed DC motor.
An improved 2D LiDAR and camera fusion system is proposed for the 3D reconstruction of unknown environments. It combines the advantages of dense 2D point cloud and rich color image, adopting a differential evolutionar...
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An improved 2D LiDAR and camera fusion system is proposed for the 3D reconstruction of unknown environments. It combines the advantages of dense 2D point cloud and rich color image, adopting a differential evolutionary nonlinear tracking PID to control the pitching motion of LiDAR and camera accurately. The quadratic polynomial transition function is used to optimize the pitching trajectory. The environment was scanned by the system and converted into a 3D colored point cloud by the data fusion algorithm. The experimental results show: the proposed PID control algorithm can accurately control the pitching motion with a small average error (0.0267 degrees) and significantly reduce the point cloud inhomogeneity (0.00698);the processing time for converting each 2D point cloud into the 3D point cloud is about 0.6 ms;combined with the data fusion algorithm, the system can obtain the dense colored 3D point cloud;compared with binocular camera, depth camera and 3D LiDAR under the condition of strong light interference, the fusion system outperforms, with the reconstruction object errors of distance, length and width of 0.23%, 0.17% and 0.46% respectively. In conclusion, the system can obtain homogeneous, and dense colored 3D point cloud in real time while ensuring stable refresh frame rate.
Due to the increasing deployment of the Internet of Things (IoT) in the mining industry, portable gas monitoring devices have been widely used. Sensor calibration of large-scale portable gas monitoring devices is beco...
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Due to the increasing deployment of the Internet of Things (IoT) in the mining industry, portable gas monitoring devices have been widely used. Sensor calibration of large-scale portable gas monitoring devices is becoming an urgent problem to be solved. An online sensor calibration algorithm based on n-tuple and opportunistic communication is proposed based on the specific characteristics (i.e., 'single-sensor, multi-position' and 'multi-sensor, single-position') of each portable gas monitoring device employed. In this paper, data collected from portable and fixed sensors were defined as multi-dimensional data points and gas monitoring data pairs, respectively. The cluster-based self-adaptive weighted data fusion algorithm and multi-period single sensor reliability fusionalgorithm were proposed and used for overall judging. The overall judgments were broadcast to each wireless access point by network, and the reliability of the calibration information transmission was enhanced by opportunistic communications. The simulation results revealed that efforts required for the calibration of portable sensors were reduced significantly, and their reliability was improved.
作者:
Tian, JianGao, LuluHenan Univ
Sch Phys Educ Kaifeng 475000 Henan Peoples R China Henan Univ
Sch Phys Educ Minsheng Coll Kaifeng 475000 Henan Peoples R China
This article discusses the monitoring of physiological indicators during exercise, combined with the data fusion algorithm of the smart city Internet of Things health. We use the hash value of the tuple key to the cor...
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This article discusses the monitoring of physiological indicators during exercise, combined with the data fusion algorithm of the smart city Internet of Things health. We use the hash value of the tuple key to the corresponding data block of the node, use the data block record to obtain the response of the target node, and output the data tuple. It is used as a measure of the load balance of health data streams to determine whether load migration is needed and to determine the way and amount of migration tasks to make migration decisions. The simulation experiments show that the method has good computational performance and dynamic load balancing. A series of mean arterial pressure and heart rate of patients and non-stationary health data, and a series of blood pressure and heart rate of health individuals in different postures are selected to perform experiments to analyze the transfer function and power spectra in the model, validating that the model can be used to reveal the changes associated with severe systemic response syndrome (SIRS), providing a hypothesis for the decomposition of autoregulation of physiological control under health and disease conditions.
In view of the situation that the current anode effect prediction methods can not cover all types of anode effects, or the anti-interference ability is poor, or the prediction advance is very small, this paper propose...
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ISBN:
(纸本)9781728176871
In view of the situation that the current anode effect prediction methods can not cover all types of anode effects, or the anti-interference ability is poor, or the prediction advance is very small, this paper proposes a method to predict the global anode effect based on the local effect detection, that is, by using the local signal before forming the global anode effect instead of the cell voltage of the whole cell, the local or local anode effect can be detected Anode effect in local anode. Therefore, based on the internal structure of aluminum reduction cell, we divide the area. Then, the potential periodicity of anode current is obtained by analyzing the power spectrum of anode current. Finally, a local effect detection model based on datafusion method is used to predict the occurrence of global effects. The effectiveness of the algorithm is illustrated by the anode current data measured on-line during the actual operation of aluminum electrolysis.
The world has approximately 253 million visually impaired (VI) people according to a report by the world health organization (WHO) in 2014. Thirty-six million people are estimated to be blind. According to WHO, 217 mi...
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The world has approximately 253 million visually impaired (VI) people according to a report by the world health organization (WHO) in 2014. Thirty-six million people are estimated to be blind. According to WHO, 217 million people are estimated to have moderate to severe visual impairment. An important factor that motivated this research is the fact that 90% of VI people live in developing countries. Several systems were designed to improve the quality of the life of VI people and support their mobility. Unfortunately, none of these systems are considered to be a complete solution for VI people and these systems are very expensive. We present in this paper an intelligent framework for supporting VI people. The proposed work integrates sensor-based and computer vision-based techniques to provide an accurate and economical solution. These techniques allow us to detect multiple objects and enhance the accuracy of the collision avoidance system. In addition, we introduce a novel obstacle avoidance algorithm based on the image depth information and fuzzy logic. By using the fuzzy logic, we were able to provide precise information to help the VI user in avoiding front obstacles. The system has been deployed and tested in real-time scenarios. An accuracy of 98% was obtained for detecting objects and 100% accuracy in avoiding the detected objects.
This study proposes a novel data fusion algorithm in sensor networks with simultaneous presence of set-membership and stochastic Gaussian measurement uncertainties. The proposed method is grounded in the marriage of e...
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This study proposes a novel data fusion algorithm in sensor networks with simultaneous presence of set-membership and stochastic Gaussian measurement uncertainties. The proposed method is grounded in the marriage of ellipsoidal calculus theory and data compression algorithm. The point-valued measurement and the set-valued measurement are compressed into a uniform framework during the estimation. An optimal Kalman gain is obtained that minimises the upper bound of the mean square error of the estimation set. The proposed algorithm is applied to the target tracking problem and the estimation results show that the proposed algorithm improves the tracking performance.
Magnetic orientation systems have widely been used by measuring the earth magnetic field and provide a pervasive source of directional information. However, to obtain the high precision, orientation systems must be co...
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Magnetic orientation systems have widely been used by measuring the earth magnetic field and provide a pervasive source of directional information. However, to obtain the high precision, orientation systems must be compensated prior to use for the various errors of magnetometers such as the bias, misalignment and inconsistence in sensitivity, and the pitch and roll angles, especially in dynamic state. In this study, magnetic orientation system mainly consist of three single-axis magnetometers, a tri-axis accelerometer and a tri- axis gyroscope were developed. An error-separation method was introduced to calibrate magnetometers. data from magnetometers, accelerometer and gyroscope were fused based on Kalman filtering. In addition, accelerometer and gyroscope were also calibrated before datafusion. Experimental results showed the heading error of magnetic orientation system was about 0.1 degrees in a static state, and <3 degrees in a dynamic state, which proved the effectivities of the calibration methods and data fusion algorithm.
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