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Acoustic Sources Localization in 3D Using Multiple Spherical Arrays
Wang, Fangzhou,Pan, Xi The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
Direction of arrival (DOA) estimation of multiple sources using sensor arrays has been widely studied in the last few decades, particularly, the spherical harmonic analysis utilizing a spherical array. Both the number of sensors on the aperture and size of the sphere can affect the estimation accuracy dramatically. However, those two factors are conflicted to each other in a single spherical array. In this paper, a multiple spherical arrays structure is proposed to provide an alternative design to the traditional single spherical array for the spherical harmonic decomposition, to obtain better localization performance. The new structure consists of several identical spheres in a given area, and the microphones are placed identically on each sphere. The spherical harmonic analysis algorithm using the new multiple array structure for the problem of multiple acoustic sources localization is presented. Simulation results show that the multiple spherical arrays can provide a more accurate direction of arrival (DOA) estimation for the multiple sources than that of a single spherical array, distinguish several adjacent sources more efficiently, and reduce the number of microphones on each sphere without decreasing its’ estimation accuracy.
Acoustic Sources Localization in 3D Using Multiple Spherical Arrays
Fangzhou Wang,Xi Pan 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
Direction of arrival (DOA) estimation of multiple sources using sensor arrays has been widely studied in the last few decades, particularly, the spherical harmonic analysis utilizing a spherical array. Both the number of sensors on the aperture and size of the sphere can affect the estimation accuracy dramatically. However, those two factors are conflicted to each other in a single spherical array. In this paper, a multiple spherical arrays structure is proposed to provide an alternative design to the traditional single spherical array for the spherical harmonic decomposition, to obtain better localization performance. The new structure consists of several identical spheres in a given area, and the microphones are placed identically on each sphere. The spherical harmonic analysis algorithm using the new multiple array structure for the problem of multiple acoustic sources localization is presented. Simulation results show that the multiple spherical arrays can provide a more accurate direction of arrival (DOA) estimation for the multiple sources than that of a single spherical array, distinguish several adjacent sources more efficiently, and reduce the number of microphones on each sphere without decreasing its’ estimation accuracy.
Wang, Dandan,Zhao, Gong-Bo,Wang, Yuting,Percival, Will J,Ruggeri, Rossana,Zhu, Fangzhou,Tojeiro, Rita,Myers, Adam D,Chuang, Chia-Hsun,Baumgarten, Falk,Zhao, Cheng,Gil-Marí,n, Hé,ctor,Ross, Oxford University Press 2018 MONTHLY NOTICES- ROYAL ASTRONOMICAL SOCIETY Vol.477 No.2
<B>Abstract</B><P>We present a measurement of the anisotropic and isotropic Baryon Acoustic Oscillations (BAO) from the extended Baryon Oscillation Spectroscopic Survey Data Release 14 quasar sample with optimal redshift weights. Applying the redshift weights improves the constraint on the BAO dilation parameter α(zeff) by 17 per cent. We reconstruct the evolution history of the BAO distance indicators in the redshift range of 0.8 < z < 2.2. This paper is part of a set that analyses the eBOSS DR14 quasar sample.</P>
Shuo Wang,Jiangfeng Xu,Fangzhou Wang,Shenshen Ruan 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.2
In the printing process, the surface of the outer package printed matter is prone to defects such as chromatic aberration and misting, leading to a defective product. It is necessary to take an effective method to identify and detect surface defects in printed matter. In this paper, the application of machine vision technology in the detection of defects in outer package was studied. Firstly, a machine vision image acquisition device based on charge coupled device (CCD) camera was designed; secondly, the obtained image was processed by graying the average method, then OTSU binarization was performed after denoising by median filtering, and finally an improved differential matching method was designed for defect detection. The example analysis showed that the clear defect image of the outer package could be obtained by using the method proposed in this paper. The detection rate of the method in detecting 2,000 images reached 99.4%, and the average detection time was 103 ms. In the detection of 5,000 images, the detection rate of the manual detection method was 81%, but the detection rate of the method proposed in this paper was 99.1%. The experimental results proved the reliability of the method and provided some theoretical basis for the further application of defect detection technology based on machine vision in the print industry, which was conducive to the good development of the print industry.
A Method for Quantitative Fault Diagnosability Analysis of Systems with Probabilistic Sensor Faults
Fangzhou Fu,Dayi Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8
Quantitative analysis of diagnosability performance provides a deep insight into the structural property of systems, which enables the selection of a model with better diagnosability. A method for quantitative probabilistic sensor fault diagnosability analysis is proposed in this technical note. New definitions of distinguishability are given to measure diagnosability performance among specific faults and fault modes via the principle of weight, which take both noises and distribution laws of probabilistic sensor faults into consideration. Furthermore, some sufficient and necessary conditions for isolating different fault modes are theoretically given. The effectiveness of the proposed method is verified by a numerical example.
Tuoya Wulan,Peijun Wang,Chengxin Xia,Xinyu Liu,Mei Liu,Fangzhou Liu,Ou Zhao,Lulu Zhang 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.42 No.1
This paper presents a study on the behavior of a bolted T-stub to square tube connection using Thread-fixed Oneside Bolts (TOBs) through tests and numerical simulations. It outlines a research work of four connections with focus on the failure modes and strengths of the connection under tensile load. It was observed that the thread anchor failure caused by shear failure of hole threads controlled the final failure of the connection in the tests. Meanwhile, the out-of-plane deformation of tube wall resulted in the contact separation between hole threads and bolt threads, which in turn reduced the shear strength of hole threads. Finite element models (FEMs) allowing for the configuration details of the TOBs fixed connection are then developed and compared with the test results. Subsequently, the failure mechanism of hole threads and stress distribution of each component are analyzed based on FEM results. It was concluded that the ultimate strength of connection was not only concerned with the shear strength of hole threads, but also was influenced by the plastic out-of-plane deformation of tube wall. These studies lay a foundation for the establishment of suitable design methods of this type of connection.
Preparation of PEO ceramic coating on Ti alloy and its high temperature oxidation resistance
Yongjun Xu,Zhongping Yao,Fangzhou Jia,Yunlong Wang,Zhaohua Jiang,Haitao Bu 한국물리학회 2010 Current Applied Physics Vol.10 No.2
Ceramic coatings were prepared in Na2SiO3–Na2CO3–NaOH system by pulsed bi-polar plasma electrolytic oxidation on Ti–6Al–4V alloy. The phase composition, structure and the elemental distribution of the coatings were studied by XRD, SEM and energy dispersive spectroscopy, respectively. The thermal shock resistance of the coated samples at 850 ℃ was evaluated by the thermal shock tests. The high temperature oxidation resistance of the coating samples at 500 ℃ was investigated. The results showed that the coating was mainly composed of rutile- and anatase TiO2, Increasing the concentration of Na2SiO3, TiO2content decreased gradually while the thickness of the coating increased. There were a large amount of micro pores and sintered particles on the surface of the coatings. Increasing concentration of Na2SiO3, the sintered particles on the surface turned large, and the Si content increased while the Ti content decreased gradually. When the concentration of Na2SiO3 was 15 g/L, the thermal shock resistance of the coatings was better than that of the coatings that prepared under other Na2SiO3 concentrations. The coating samples prepared under the optimized technique process based on the thermal shock tests improved the high temperature oxidation resistance at 500 ℃ greatly, whether considering the isothermal oxidation or the cyclic oxidation.
Yang You,Le Liu,Xiaojing Huang,Peijun Wang,Fangzhou Liu 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.4
The tensile behavior of the Thread-fixed One-side Bolt (TOB) at high temperatures was studied using the Finite Element Modeling (FEM) to explore the structural responses that could not be measured in tests. The accuracy of the FEM was verified using the test results from the failure mode, load-displacement curve as well as yielding load. Three typical failure modes of TOB connected T-stubs were observed, which were the Flange Yielding (FY), the Bolt Failure (BF) and the Coupling Failure mode (CF). The influence of the flange thickness tb and the temperature θ on the tensile behavior of the T-stub were discussed. The initial stiffness and the yielding load decreased with the increase of the temperature. The T-stubs almost lost their resistance when the temperature exceeded 700℃. The failure modes of T-stubs were mainly decided by the flange thickness, which relates to the anchorage of the hole threads and the bending resistance of flange. The failure mode could also be changed by the high temperature. Design equations in EN 1993-1-8 were modified and verified by the FEM results. The results showed that these equations could predict the failure mode and the yielding load at different temperatures with satisfactory accuracy.