This paper introduces a kind of photoelectric hybridization measuring process.Owing to the characteristics of the compact form of shearing equipment to be analyzed and the connecting rod existing in two directional st...This paper introduces a kind of photoelectric hybridization measuring process.Owing to the characteristics of the compact form of shearing equipment to be analyzed and the connecting rod existing in two directional stress state during operation etc.,it is hard to obtain results by means of single electrical testing process.For this reason,this paper derives a group of calculation formulas of hybridization measuring process through comprehensive discussion of photoelectric analysis and electrical testing theories,thus providing an analytical method for actual measurement of complex engineering problems.展开更多
A refractive index (RI) sensor based on hybrid long-period fiber grating (LPFG) with multimode fiber core (MMFC) is proposed and demonstrated. The surrounding RI can be determined by monitoring the separation be...A refractive index (RI) sensor based on hybrid long-period fiber grating (LPFG) with multimode fiber core (MMFC) is proposed and demonstrated. The surrounding RI can be determined by monitoring the separation between the resonant wavelengths of the LPFG and MMFC since the resonant wavelengths of the LPFG and MMFC will shift in opposite directions when the surrounding RI changes. Experimental results show that the sensor possesses an enhanced sensitivity of 526.92nm/RIU in the RI range of 1.387-1.394 RIU. The response to the temperature is also discussed.展开更多
The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called "knee" by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC...The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called "knee" by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100-700 TeV). The observed energy spectrum is compatible with a single power law with index γ=-2.63±0.06.展开更多
Reflectance model is a basic concept in computer vision. Some existing models combining the classical diffuse reflectance model and those for surfaces containing specular components can approximately describe real ref...Reflectance model is a basic concept in computer vision. Some existing models combining the classical diffuse reflectance model and those for surfaces containing specular components can approximately describe real reflectance. But the ratio of diffuse and specular reflection decided manually has no clear meaning. We propose a new polynomial hybrid reflectance model. The reflectance map equation with a known shape (for example cylinder) as a sample is used to estimate parameters of the proposed reflectance model by least square regression algorithm. Then the reflectance parameters for surfaces of the same class of materials can be determined. Experiments are performed for a metal surface. The synthesis images produced by the proposed method and existing ones are compared with the real acquired image, and the results show that the proposed reflectance model is suitable for describing real reflectance.展开更多
Metamodels have been widely used as an alternative for expensive physical experiments or complex,time-consuming computational simulations to provide a fast but accurate analysis.However,challenge remains in the prior ...Metamodels have been widely used as an alternative for expensive physical experiments or complex,time-consuming computational simulations to provide a fast but accurate analysis.However,challenge remains in the prior determination of the most suitable metamodel for a particular case because of the lack of information about the actual behavior of a system.In addition,existing studies on metamodels have largely restricted on solving deterministic problems(e.g.,data from finite element models),whereas some real-life engineering problems(e.g.,data from physical experiment)are stochastic problems with noisy data.In this work,a robust ensemble of metamodels(EMs)is proposed by combining three regression stand-alone metamodels in a weighted sum form.The weight factor is adaptively determined according to the hybrid error metric,which combines global and local error measures to improve the accuracy of the EMs.Furthermore,three typical individual metamodels that can filter noise are selected to construct the EMs to extend their application in practical engineering problems.Three well-known benchmark problems with different levels of noise and three engineering problems are used to verify the effectiveness of the proposed EMs.Results show that the proposed EMs have higher accuracy and robustness than the individual metamodels and other typical EMs in major cases.展开更多
Purpose–The passive source localization(PSL)problem using angles of arrival(AOA),time differences of arrival(TDOA)or gain ratios of arrival(GROA)is generally nonlinear and nontrival.In this research,the purpose of th...Purpose–The passive source localization(PSL)problem using angles of arrival(AOA),time differences of arrival(TDOA)or gain ratios of arrival(GROA)is generally nonlinear and nontrival.In this research,the purpose of this paper is to design an accurate hybrid source localization approach to solve the PSL problem.The inspiration is drawn from the fact that the bearings,TDOAs and GROAs are complementary in terms of their geometry properties.Design/methodology/approach–The maximum-likelihood(ML)method is reexamined by using hybrid measurements.Being assisted by the bearings,a new hybrid weighted least-squares(WLS)method is then proposed by jointly utilizing the bearing,TDOA and GROA measurements.Findings–Theoretical performance analysis illustrates that the mean-square error of the ML or WLS method can attain the Cramér-Rao lower bound for Gaussian noiseover small error region.However,the WLS method has much lower computational complexity than the ML algorithm.Compared with the AOA-only,TDOA-only,AOA-TDOA,TDOA-GROA methods,the localization accuracy can be greatly improved by combining the AOAs,TDOAs and GROAs,especially for some specific geometries.Originality/value–A novel bearing-assisted TDOA-GROA method is proposed for source localization,and a new hybrid WLS estimator is presented inspired from the fact that the bearings,TDOAs and GROAs are complementary in terms of their geometry properties.展开更多
文摘This paper introduces a kind of photoelectric hybridization measuring process.Owing to the characteristics of the compact form of shearing equipment to be analyzed and the connecting rod existing in two directional stress state during operation etc.,it is hard to obtain results by means of single electrical testing process.For this reason,this paper derives a group of calculation formulas of hybridization measuring process through comprehensive discussion of photoelectric analysis and electrical testing theories,thus providing an analytical method for actual measurement of complex engineering problems.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61327012 and 61505160the Natural Science Foundation of Shaanxi Province under Grant No 2016JQ6021the Shaanxi Key Laboratory of Optical Information Technology under Grant No OIT201601
文摘A refractive index (RI) sensor based on hybrid long-period fiber grating (LPFG) with multimode fiber core (MMFC) is proposed and demonstrated. The surrounding RI can be determined by monitoring the separation between the resonant wavelengths of the LPFG and MMFC since the resonant wavelengths of the LPFG and MMFC will shift in opposite directions when the surrounding RI changes. Experimental results show that the sensor possesses an enhanced sensitivity of 526.92nm/RIU in the RI range of 1.387-1.394 RIU. The response to the temperature is also discussed.
基金Supported by NSFC(10975145,11075170)Knowledge Innovation Fund(H85451D0U2)of IHEP+2 种基金Chinese Ministry of Science and Technology,Chinese Academy of Science,Key Laboratory of Particle Astrophysics,CASin Italy by the Istituto Nazionale di Fisica Nucleare(INFN)Ministero dell’Istruzione,dell’Università e della Ricerca(MIUR)
文摘The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called "knee" by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100-700 TeV). The observed energy spectrum is compatible with a single power law with index γ=-2.63±0.06.
基金This work was supported by the National Natural Sci-ence Foundation of China under Grant No.60502021.
文摘Reflectance model is a basic concept in computer vision. Some existing models combining the classical diffuse reflectance model and those for surfaces containing specular components can approximately describe real reflectance. But the ratio of diffuse and specular reflection decided manually has no clear meaning. We propose a new polynomial hybrid reflectance model. The reflectance map equation with a known shape (for example cylinder) as a sample is used to estimate parameters of the proposed reflectance model by least square regression algorithm. Then the reflectance parameters for surfaces of the same class of materials can be determined. Experiments are performed for a metal surface. The synthesis images produced by the proposed method and existing ones are compared with the real acquired image, and the results show that the proposed reflectance model is suitable for describing real reflectance.
基金This work was supported by the National Key R&D Program of China(Grant No.2017YFD0400405)。
文摘Metamodels have been widely used as an alternative for expensive physical experiments or complex,time-consuming computational simulations to provide a fast but accurate analysis.However,challenge remains in the prior determination of the most suitable metamodel for a particular case because of the lack of information about the actual behavior of a system.In addition,existing studies on metamodels have largely restricted on solving deterministic problems(e.g.,data from finite element models),whereas some real-life engineering problems(e.g.,data from physical experiment)are stochastic problems with noisy data.In this work,a robust ensemble of metamodels(EMs)is proposed by combining three regression stand-alone metamodels in a weighted sum form.The weight factor is adaptively determined according to the hybrid error metric,which combines global and local error measures to improve the accuracy of the EMs.Furthermore,three typical individual metamodels that can filter noise are selected to construct the EMs to extend their application in practical engineering problems.Three well-known benchmark problems with different levels of noise and three engineering problems are used to verify the effectiveness of the proposed EMs.Results show that the proposed EMs have higher accuracy and robustness than the individual metamodels and other typical EMs in major cases.
文摘Purpose–The passive source localization(PSL)problem using angles of arrival(AOA),time differences of arrival(TDOA)or gain ratios of arrival(GROA)is generally nonlinear and nontrival.In this research,the purpose of this paper is to design an accurate hybrid source localization approach to solve the PSL problem.The inspiration is drawn from the fact that the bearings,TDOAs and GROAs are complementary in terms of their geometry properties.Design/methodology/approach–The maximum-likelihood(ML)method is reexamined by using hybrid measurements.Being assisted by the bearings,a new hybrid weighted least-squares(WLS)method is then proposed by jointly utilizing the bearing,TDOA and GROA measurements.Findings–Theoretical performance analysis illustrates that the mean-square error of the ML or WLS method can attain the Cramér-Rao lower bound for Gaussian noiseover small error region.However,the WLS method has much lower computational complexity than the ML algorithm.Compared with the AOA-only,TDOA-only,AOA-TDOA,TDOA-GROA methods,the localization accuracy can be greatly improved by combining the AOAs,TDOAs and GROAs,especially for some specific geometries.Originality/value–A novel bearing-assisted TDOA-GROA method is proposed for source localization,and a new hybrid WLS estimator is presented inspired from the fact that the bearings,TDOAs and GROAs are complementary in terms of their geometry properties.