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Absolute Wall Thickness Measurement of Conducting Plates Using Pulsed Eddy Currents
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作者 Victor-O. de Haan Riccardo Scottini 《Journal of Electromagnetic Analysis and Applications》 2024年第3期25-41,共17页
The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a prob... The method using pulsed eddy currents to determine the thickness of a conduction plate is extended to enable the simultaneous measurement of the plate thickness and material properties. For optimal performance, a probe must be designed depending on the thickness range that should be accessible. The need for a calibration of the material properties of a conducting plate to enable the measurement of its thickness has been removed. All that is needed is a probe with known dimensions and suitable hardware to create a current pulse and measure a transient magnetic induction. 展开更多
关键词 Pulsed Eddy Currents Wall Thickness Absolute and relative measurements
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Multipath mitigation method based on Gaussian mixture model in RF relative measurement 被引量:1
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作者 Weiqing MU Rongke LIU +1 位作者 Zijie WANG Xinxin YANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第12期2270-2279,共10页
Radio Frequency(RF) technology represents a high-precision relative navigation solution that has significant potential for application to earth-orbiting satellites. In precision applications, multipath errors dominate... Radio Frequency(RF) technology represents a high-precision relative navigation solution that has significant potential for application to earth-orbiting satellites. In precision applications, multipath errors dominate the total error because observables, which are used to estimate carrier-phase integer ambiguity, are not always subject to a Gaussian distribution when dualfrequency ambiguity estimation methods are used in the presence of multipath. As it has been shown that ranging observables obey a Gaussian mixture distribution, this study proposes improvements to the accuracy of estimation based on multipath mitigation founded on the Gaussian mixture model. To this end, such a model is created for integer ambiguity resolution in the presence of multipath, using which the theoretical error in dual-frequency ambiguity estimation is derived.Expectation Maximization(EM), which aids dual-frequency ambiguity estimation, is subsequently proposed to reduce the effect of multipath errors. Finally, two experimental scenarios are implemented to test the performance of the proposed method. The results show that EM-aided dualfrequency ambiguity estimation reduces the range error to approximately 20% in comparison with simple dual-frequency ambiguity estimation. Therefore the proposed technique is effective for multipath mitigation in RF relative measurement. 展开更多
关键词 Dual-frequency ambiguity estimation Gaussian mixture model Multipath mitigation RF relative measurement Satellite navigation
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Relative Irradiance Measurement and Bonding Configurations of Amorphous Fluorinated Carbon Films Deposited by Electron Cyclotron Resonance Plasma
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作者 叶超 康健 +1 位作者 宁兆元 程珊华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2000年第5期469-474,共6页
a-C:F films are deposited by microwave electron cyclotron resonance (ECR)plasma chemical vapor deposition (CVD) using trifluoromethane (CHF3) and benzene (C6H6) as source gases at different microwave powers. The radic... a-C:F films are deposited by microwave electron cyclotron resonance (ECR)plasma chemical vapor deposition (CVD) using trifluoromethane (CHF3) and benzene (C6H6) as source gases at different microwave powers. The radicals in plasma originating from source gases dissociation are analyzed by relative irradiance measurement. The bonding configurations and binding state of a-C:F films are measured with Fourier-transformed infrared spectrometer (FTIR) and x-ray photoelectron spectroscopy (XPS). The results show that a-C:F films are mainly composed of CF radical at lower powers but of CF2 radical at higher powers. The deposition of films is related to the radicals generated in plasma and the main bonding configurations are dependent on the ratio of CF to CF2 radicals in films. 展开更多
关键词 CHF XPS cm relative Irradiance measurement and Bonding Configurations of Amorphous Fluorinated Carbon Films Deposited by Electron Cyclotron Resonance Plasma
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Joint processing and analysis of seismic gravity measurements in Capital Circle area
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作者 贾民育 马丽 +3 位作者 刘少明 张晶 孙少安 王武星 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第4期438-447,共10页
In Capital Circle area, there are three groups of repeated gravity measurements observed by different institutes using different instruments or methods. The simultaneous adjustment of absolute and relative measurement... In Capital Circle area, there are three groups of repeated gravity measurements observed by different institutes using different instruments or methods. The simultaneous adjustment of absolute and relative measurements and the elimination of systematic error among the relative measurements have been carded out in this paper. Thus an unified temporal gravity change system with absolute reference has been established. On the basis of this, the crustal subsidence effect on gravity, which belongs to non-tectonic factor, is analyzed and the station displacement corrections are carried out, so that the long-wave disturbance is eliminated. So far our following aims are realized: the advantages of the absolute and relative measurement methods are complementary to each other; the contradiction and environment disturbance are eliminated; the amounts of information are enlarged; the sampling interval of time domain is compressed. In a word, the ability of identifying the tectonic activity process is enhanced. The results show that: there are systematic errors between the two groups of relative measurements and within the data of 10 campaigns ; the uneven local crustal subsidence in the southeast of the study area results in a linear rise of gravity value at 10 stations; they can be corrected by the regression analysis. The maps of revised temporal gravity change can obviously and integrally reflect the Ms=5.0 earthquake in Guye on October 6, 1995. 展开更多
关键词 Capital Circle area temporal gravity change relative measurement absolute measurement unified system
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Analysis and Application of the Synthetic Relative Measuring Method in On-Line Monitoring for Capacitive Equipment in Power Systems
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作者 Qing Guo Li-Jun Qin Hua-Wei Jin 《Journal of Electronic Science and Technology》 CAS 2011年第3期270-277,共8页
On-line measurement for dielectric loss angle can effectively monitor the insulation condition of capacitive equipment in power systems. Synthetic relative measuring methods not only markedly overcome the shortcomings... On-line measurement for dielectric loss angle can effectively monitor the insulation condition of capacitive equipment in power systems. Synthetic relative measuring methods not only markedly overcome the shortcomings of traditional absolute measuring methods but also greatly improve the accuracy of dielectric loss angle measurement. However, synthetic relative measuring methods based on two or three pieces of capacitive equipment do not have the characteristic of generality. In this paper, a principle of synthetic relative measuring method is presented. The example of application for synthetic relative methods based on three and four pieces of capacitive equipment running in the same phase is taken to present the failure judgment matrices for N pieces of equipment. According to these matrices, the fault condition of N pieces of capacitive equipment can be watched, which is more general. Then some problems needing to be concerned along with two diagnostic methods used in diagnostic system are introduced. Finally, two programmable flow charts for the two methods are given and corresponding examples demonstrate their feasibility in practice. 展开更多
关键词 Index Terms-Capacitive equipment dielectric loss angle on-line monitoring synthetic relative measuring method failure judgment matrix.
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An Alternative Approach to AIC and Mallow’s Cp Statistic-Based Relative Influence Measures (RIMS) in Regression Variable Selection
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作者 Umeh Edith Uzoma Obulezi Okechukwu Jeremiah 《Open Journal of Statistics》 2016年第1期70-75,共6页
Outlier detection is an important data screening type. RIM is a mechanism of outlier detection that identifies the contribution of data points in a regression model. A BIC-based RIM is essentially a technique develope... Outlier detection is an important data screening type. RIM is a mechanism of outlier detection that identifies the contribution of data points in a regression model. A BIC-based RIM is essentially a technique developed in this work to simultaneously detect influential data points and select optimal predictor variables. It is an addition to the body of existing literature in this area of study to both having an alternative to the AIC and Mallow’s Cp Statistic-based RIM as well as conditions of no influence, some sort of influence and perfectly single outlier data point in an entire data set which are proposed in this work. The method is implemented in R by an algorithm that iterates over all data points;deleting data points one at a time while computing BICs and selecting optimal predictors alongside RIMs. From the analyses done using evaporation data to compare the proposed method and the existing methods, the results show that the same data cases selected as having high influences by the two existing methods are also selected by the proposed method. The three methods show same performance;hence the relevance of the BIC-based RIM cannot be undermined. 展开更多
关键词 relative Influence Measure (RIM) BIC AIC Mallow’s Cp Statistic Cook’s Distance
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Semi-analytical assessment of the relative accuracy of the GNSS/INS in railway track irregularity measurements 被引量:1
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作者 Qijin Chen Quan Zhang +1 位作者 Xiaoji Niu Jingnan Liu 《Satellite Navigation》 2021年第1期352-367,共16页
An aided Inertial Navigation System(INS)is increasingly exploited in precise engineering surveying,such as railway track irregularity measurement,where a high relative measurement accuracy rather than absolute accurac... An aided Inertial Navigation System(INS)is increasingly exploited in precise engineering surveying,such as railway track irregularity measurement,where a high relative measurement accuracy rather than absolute accuracy is emphasized.However,how to evaluate the relative measurement accuracy of the aided INS has rarely been studied.We address this problem with a semi-analytical method to analyze the relative measurement error propagation of the Global Navigation Satellite System(GNSS)and INS integrated system,specifically for the railway track irregularity measurement application.The GNSS/INS integration in this application is simplified as a linear time-invariant stochastic system driven only by white Gaussian noise,and an analytical solution for the navigation errors in the Laplace domain is obtained by analyzing the resulting steady-state Kalman filter.Then,a time series of the error is obtained through a subsequent Monte Carlo simulation based on the derived error propagation model.The proposed analysis method is then validated through data simulation and field tests.The results indicate that a 1 mm accuracy in measuring the track irregularity is achievable for the GNSS/INS integrated system.Meanwhile,the influences of the dominant inertial sensor errors on the final measurement accuracy are analyzed quantitatively and discussed comprehensively. 展开更多
关键词 Inertial surveying relative measurement accuracy Error propagation modeling Steady-state Kalman filter Precise engineering surveying
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Coseismic gravity and displacement changes of Japan Tohoku earthquake(Mw 9.0) 被引量:1
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作者 Xinlin Zhang Shuhei Okubo +1 位作者 Yoshiyuki Tanaka Hui Li 《Geodesy and Geodynamics》 2016年第2期95-100,共6页
The greatest earthquake in the modern history of Japan and probably the fourth greatest in the last 100 years in the world occurred on March 11, 2011 off the Pacific coast of Tohoku.Large tsunami and ground motions ca... The greatest earthquake in the modern history of Japan and probably the fourth greatest in the last 100 years in the world occurred on March 11, 2011 off the Pacific coast of Tohoku.Large tsunami and ground motions caused severe damage in wide areas, particularly many towns along the Pacific coast. So far, gravity change caused by such a great earthquake has been reported for the 1964 Alaska and the 2010 Maule events. However, the spatial-temporal resolution of the gravity data for these cases is insufficient to depict a co-seismic gravity field variation in a spatial scale of a plate subduction zone. Here, we report an unequivocal co-seismic gravity change over the Japanese Island, obtained from a hybrid gravity observation(combined absolute and relative gravity measurements). The time interval of the observation before and after the earthquake is within 1 year at almost all the observed sites, including 13 absolute and 16 relative measurement sites, which deduced tectonic and environmental contributions to the gravity change. The observed gravity agrees well with the result calculated by a dislocation theory based on a self-gravitating and layered spherical earth model. In this computation, a co-seismic slip distribution is determined by an inversion of Global Positioning System(GPS) data. Of particular interest is that the observed gravity change in some area is negative where a remarkable subsidence is observed by GPS, which can not be explained by simple vertical movement of the crust. This indicated that the mass redistribution in the underground affects the gravity change. This result supports the result that Gravity Recovery and Climate Experiment(GRACE) satellites detected a crustal dilatation due to the 2004 Sumatra earthquake by the terrestrial observation with a higher spatial and temporal resolution. 展开更多
关键词 Tohoku earthquake(Mw 9.0) Co-seismic gravity change Co-seismic displacement change Coseismic geoid change Dislocation theory Global Positioning System Absolute gravity measurement relative gravity measurement
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STUDY ON MEASURE OF TECHNICAL INNOVATION ABILITY IN MEDIUM AND SMALL MANUFACTURING ENTERPRISES
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作者 BiKexin DingXiaohui +1 位作者 ZhangTiezhu FengYingjun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第1期40-45,共6页
Measure index system of technical innovation in medium and smallmanufacturing enterprises is established according to principles of exploration, adaptability,standardization, generalization, feasibility, comparability... Measure index system of technical innovation in medium and smallmanufacturing enterprises is established according to principles of exploration, adaptability,standardization, generalization, feasibility, comparability and combination of economic benefit andcontinual development. It includes index of technical innovation capacity, informationaladministration on technical innovation, and investment of technical innovation, economic benefit,green technical level, social contribution and other influential indexes. Approach to measure oftechnical innovation in medium and small manufacturing enterprises is presented based on combinationof grey relation and fuzzy hiberarchy analysis, and conclusions are drawn based on practicalanalysis of 20 medium and small enterprises, which provides the basis for the medium and smallenterprises to select technical innovation policies and the government to constitute relativepolicies. 展开更多
关键词 Medium and small manufacturing enterprises Technical innovation ability Measure Grey relation Fuzzy hierarchy analysis
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Similarity evaluation of stratum anti-drilling ability and a new method of drill bit selection
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作者 YAN Tie XU Rui +4 位作者 SUN Wenfeng LIU Weikai HOU Zhaokai YUAN Yuan SHAO Yang 《Petroleum Exploration and Development》 CSCD 2021年第2期450-459,共10页
Considering the stratum anti-drilling ability,drill bit working conditions,drill bit application effect and drill bit economic benefits,the similarity of stratum anti-drilling ability was evaluated by grey relational ... Considering the stratum anti-drilling ability,drill bit working conditions,drill bit application effect and drill bit economic benefits,the similarity of stratum anti-drilling ability was evaluated by grey relational analysis theory to screen out candidate drill bits with reference values.A new comprehensive performance evaluation model of drill bit was established by constructing the absolute ideal solution,changing the relative distance measurement method,and introducing entropy weight to work out the closeness between the candidate drill bits and ideal drill bits and select the reasonable drill bit.Through the construction of absolute ideal solution,improvement of relative distance measurement method and introduction of entropy weight,the inherent defects of TOPSIS decision analysis method,such as non-absolute order,reverse order and unreasonable weight setting,can be overcome.Simple in calculation and easy to understand,the new bit selection method has good adaptability to drill bit selection using dynamic change drill bit database.Field application has proved that the drill bits selected by the new drill bit selection method had significant increase in average rate of penetration,low wear rate,and good compatibility with the drilled formations in actual drilling.This new method of drill bit selection can be used as a technical means to select drill bits with high efficiency,long life and good economics in oilfields. 展开更多
关键词 drill bit selection stratum anti-drilling ability grey relational analysis absolutely ideal solution relative distance measurement method entropy weight comprehensive performance of drill bit
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The association of olanzapine-induced metabolic disturbance related measures with TCF7L2 gene expression
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作者 李然然 《China Medical Abstracts(Internal Medicine)》 2017年第1期62-63,共2页
Objective To investigate the relationship between olanzapine induced metabolic disturbance related measures and TCF7L2 gene expression.Methods Thirty adult C57BL/61 mice,in accordance with the random number table,were... Objective To investigate the relationship between olanzapine induced metabolic disturbance related measures and TCF7L2 gene expression.Methods Thirty adult C57BL/61 mice,in accordance with the random number table,were divided into 3 groups that were 展开更多
关键词 TCF The association of olanzapine-induced metabolic disturbance related measures with TCF7L2 gene expression gene
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