Piezoelectric geophones are vibration detectors that convert vibration acceleration signals into electrical signals. High performance piezoelectric materials can improve the sensitivity of piezoelectric geophone and m...
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Piezoelectric geophones are vibration detectors that convert vibration acceleration signals into electrical signals. High performance piezoelectric materials can improve the sensitivity of piezoelectric geophone and meet the need of high-resolution seismic data acquisition. The comprehensive performance of relaxor piezoelectric single crystal PMN-PT is more superior than PZT, and it is potential to be applied to high sensitivity and small volume geophones. In this paper, the central compressed geophone core model based on PMN-PT was established and theoretically analyzed. Then, a multiphysics simulation model was set up in COMSOL for simulation calculation. Finally, experimental verification was carried out. The results show that using PMN-PT in geophone core design can improve the sensitivity of the model by more than 120% compared with the traditional PZT material. The PMN-PT has the potential to be applied to high sensitivity and small volume geophones.
To ensure the efficiency of people's work while working long hours, an initiative service method with regard to degree of sleepiness for drinking service robot is proposed. It can recognize the degree of sleepines...
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To ensure the efficiency of people's work while working long hours, an initiative service method with regard to degree of sleepiness for drinking service robot is proposed. It can recognize the degree of sleepiness and provide initiative service to increase the efficiency of people's work. Degree of sleepiness is defined as three levels by observer rating, which is supposed to be associated with human actions, environmental factors, and individual factors. In addition, a model of degree of sleepiness based on Finite State Machines (FSM) is introduced. The relationship between human demands and degree of sleepiness is established through demand analysis model by which the initiative service with regard to degree of sleepiness for drinking service robot is achieved. Experiments on real initiative drinking service are performed in a multimodal emotional communication based on human-robot interaction (MEC-HRI) system, from which the experimental results show that the time of initiative service is 8 minutes earlier than that without initiative service. In prospect, the proposal could be applied to other kinds of services such as health care, safety driving assistance, and other safety work assistance.
In practical applications of electromagnetic measurement while drilling(EM-MWD),the signal-to-noise ratio(SNR)of receiver cannot always meet the requirements of reliable communication conditions due to the earth-atten...
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In practical applications of electromagnetic measurement while drilling(EM-MWD),the signal-to-noise ratio(SNR)of receiver cannot always meet the requirements of reliable communication conditions due to the earth-attenuation,interfering signal from well site,*** to solve these problems,this paper presents a BCH encoder and decoder technology based on BPSK for ***,the paper studies the relationship between BCH encoding error performance and decoding method,source length and other factors through simulation;then,we obtain an optimal length of BCH code for EM-MWD through analyzing the bit error performance of hard-decision decoding and soft-decision decoding with different lengths of BCH *** results show that the proposed algorithm can reduce the bit error rate at a lower SNR,achieving a reliable communication condition when the SNR of a received signal is *** is demonstrated the effectiveness of the proposed BCH encoder and decoder algorithm based on BPSK for EM-MWD.
Non-dominated sorting is widely used in multi-objective evolutionary algorithms. There are many approaches to non-dominated sorting, but they are computationally expensive when the number of objectives or the number o...
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Non-dominated sorting is widely used in multi-objective evolutionary algorithms. There are many approaches to non-dominated sorting, but they are computationally expensive when the number of objectives or the number of fronts becomes relatively large. This paper proposes an efficient non-dominated sorting approach based on a dominance ranking graph created in this paper. The approach takes advantages of both the dominated and non-dominated relationships, it is able to efficiently handle the case of large number of objectives/fronts. Experimental results show that the proposed algorithm outperforms its several popular variants in most of the tests.
Magnetic field generator is an essential part of the automatic measurement of geomagnetic elements. Based on the Biot-Savart law, mathematical models of magnetic field distribution of different types of magnetic field...
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Magnetic field generator is an essential part of the automatic measurement of geomagnetic elements. Based on the Biot-Savart law, mathematical models of magnetic field distribution of different types of magnetic field generators are established. The magnetic intensity and the homogenous area of them are discussed. The analysis results show that increasing the number of coils can increase magnetic intensity. Meanwhile, the designed sphere coil can generate a larger uniform magnetic field with a smaller geometric size, and overcomes the deficiencies in the space utilization of the traditional magnetic field generator. In addition, it has great potential to miniature the size of the geomagnetic measurement instruments.
Bifurcation and stability analysis for a fractional-order gene regulatory networks with time delay is researched. Firstly, taking time delay as the bifurcation parameter, the Hopf bifurcation and stability conditions ...
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A new measuring system for magnetic properties of the ferromagnetic thin film has developed based on magneto-optical Kerr effect (MOKE). This system can realize both polar MOKE and longitudinal MOKE measurements throu...
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A new measuring system for magnetic properties of the ferromagnetic thin film has developed based on magneto-optical Kerr effect (MOKE). This system can realize both polar MOKE and longitudinal MOKE measurements through the optimization of optical path and electromagnet's poles. The signal processing software on Lab View has been also designed to acquire the Kerr signal and plot the hysteresis loop. The MOKE measurements have been performed to investigate the magnetic properties of ferromagnetic films such as CoFeSiB, permalloy and NiFe/Ag/NiFe multilayer. The experimental results proved that the system has a high angular accuracy of 0.0008°.
In the continuous annealing line heating process, it is hard to get an accurate predict result only by a steady state model as it is a complex, strongly time-delayed and confounding process. This study provides a meth...
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In the continuous annealing line heating process, it is hard to get an accurate predict result only by a steady state model as it is a complex, strongly time-delayed and confounding process. This study provides a method for building a dynamic model. First analyzes the mechanism of the annealing line to get the main parameters, and then use the data-driven modeling method to get a steady state model, finally combines with dynamic algorithm to establish a dynamic model. This modeling method improves the accuracy of predict result to guarantee the efficiency of enterprises.
This paper concerns the stability analysis of discrete Takagi-Sugeno fuzzy systems with time-varying delays.A suitable Lyapunov-Krasovskii functional is constructed,and an extended reciprocally convex matrix inequalit...
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This paper concerns the stability analysis of discrete Takagi-Sugeno fuzzy systems with time-varying delays.A suitable Lyapunov-Krasovskii functional is constructed,and an extended reciprocally convex matrix inequality is used to estimate the forward difference of the *** a result,a less conservative stability criterion is ***,a numerical example is given to demonstrate the advantage of the proposed method.
The research of miniaturized XRF/XRD analyzers are carried out in this paper, especially the qualitative analysis based on EDXRF, a miniaturized energy dispersive X-ray fluorescence spectrometry platform is designed a...
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The research of miniaturized XRF/XRD analyzers are carried out in this paper, especially the qualitative analysis based on EDXRF, a miniaturized energy dispersive X-ray fluorescence spectrometry platform is designed and a qualitative elemental analysis software based on Android operating system is developed. The elemental qualitative analysis software can preprocess the X-ray feature spectrum by background eliminationsmoothing and energy coefficient calibration, after these pretreatments,the main elements of the sample can be analyzed. The experimental results show that the qualitative elemental analysis platform proposed in this paper can measure the elements of Al to Au in the periodic table, besides, the detection accuracy of multiple samples is higher than 97%. The mineral qualitative elemental analysis software proposed in this paper can be applied to any portable analysis platform based on Android operating system, moreover, it will spur advances in the development of the miniaturization and intelligent X-ray fluorescence spectrometer.
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