Guangzheng Yu^1,*, Yu Liu^1,2, Bosun Xie¹, Huali Zhou¹

Sound & Vibration, Vol.53, No.4, pp. 151-159, 2019, DOI:10.32604/sv.2019.04644

Abstract To accelerate head-related transfer functions (HRTFs) measurement, two or more independent sound sources are usually employed in the measurement system. However, the multiple scattering between adjacent sound sources may influence the accuracy of measurement. On the other hand, the directivity of sound source could induce measurement error. Therefore, a model consisting of two spherical sound sources with approximate omni-directivity and a rigid-spherical head is proposed to evaluate the errors in HRTF measurement caused by multiple scattering between sources. An example of analysis using multipole re-expansion indicates that the error of ipsilateral HRTFs are within the bound of ± 1.0 dB… More >

Hyung-Jo Jung, Jong-Jae Lee, Jeong-Su Park

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.019.125

Abstract A vision-based displacement measurement method for structural health monitoring of large-scale infrastructures such as high-rise buildings and long-span bridges is presented. The method uses digital image processing techniques including a target recognition algorithm, projection of the captured image, and calculation of the actual displacement using target geometry and the number of pixels moved. To measure the displacement of a flexible structure from a distant location which can be regarded as a fixed reference point, a novel image processing method has been devised by means of successive estimation of relative displacement and rotational angle using a synchronized vision-based system. By measuring… More >

Yufeng Nie, Yu Zhang, Yiqiang Li, Gu YT

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 123-124, 2011, DOI:10.3970/icces.2011.019.123

Abstract When the set of nodes distributed randomly is applied to approximate function, the size of the domain support of point has a great influence on the validity and accuracy of approximation. In order to study the radius of the support domain, this paper gives a new concept of the node density firstly, which not only can characterize the density level of distribution of the node and its calculation algorithm is simple, but also is easy to determine the radius of the support domain; Secondly, based on the concept of the node density, an algorithm which is used to search nodes… More >

Yukitoshi OTANI, Fumio KOBAYASHI, Yasuhiro MIZUTANI, Manabu Harada, Toru YOSHIZAWA

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 107-108, 2011, DOI:10.3970/icces.2011.019.107

Abstract A uni-axial three dimensional surface measurement by a liquid crystal digital shifter( LCDC) is proposed using a telecentric optical system. Distance information can be determined by measuring the contrast in the projected grating pattern. The magnification of the object image captured by a CCD camera is adjusted constant by changing the focus distance. A shadow less measurement of the object's area is archived by using a uni-axial system. The liquid crystal digital shifter is a powerful tool to make arbitrary intensity and frequency distribution. Surface profiles of some mechanical parts were measured to demonstrate this method. More >

Xianyu Su, Qican Zhang, Wenjing Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 77-78, 2011, DOI:10.3970/icces.2011.018.077

Abstract Fourier transform method has been widely sued on fringe analysis in optical metrology, including the structured illumination metrology and the interference metrology. The Fourier transform profilometry is one of the popular non-contact 3-D shape measurement methods, where a Ronchi grating or sinusoidal grating is projected onto a 3-D diffuse surface, and the resulting deformed grating image is detected by a CCD camera and processed by a computer. This method requires only one frame of the deformed fringe pattern to retrieve the surface of measured object, so it has obvious advantage for real-time data acquisition and 3-D measurement of dynamic process.… More >

Zeng Xiangfu, Ma Shaopeng, Ma Qinwei, Chen Pengwan

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.4, pp. 111-112, 2011, DOI:10.3970/icces.2011.017.111

Abstract In order to measure the attitude parameters of the projectile, a high-speed 3-dimensional digital image correlation (H3D-DIC) system is designed and constructed. In the H3D-DIC system, two high-speed cameras are used to capture the images of the projectile from two different directions and the 3-dimensional coordinates of the markers painted on projectile are obtained by processing the images using stereovision techniques. Because of the difference on the resolution of the two cameras, the images captured are with different magnification. Therefore, a new correlation program, in which the parameter of pixel size is also included in the correlation schedule, is designed… More >

Xue Feng Yao, Yin Ji Ma, Wen Feng Hao, Yu Chao Ke, Dai Ning Fang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.2, pp. 51-52, 2011, DOI:10.3970/icces.2011.017.051

Abstract In this paper, some applications of residual stress measurement in engineering material and structures are introduced. First, some advanced measurement technologies are described like drill hole, residual strain gauge and digital image correlations. Second, the manufacture stresses are explained. Finally, the typical measurement results about the manufacture stress are provided, including: residual stress of integrated composite T-section structures, residual stress of adhesive joint, residual stress of bending tube, residual stress of fiber interface. These results will play an important role in designing and evaluating of advanced material and structure. More >

Xue Feng^*, Xiang Wang, Guobing Zhang, Huimin Xie, Helong Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.020.115

Abstract Most ceramic materials, because of their inherent brittleness, are susceptible to catastrophic failure under conditions of thermal shock. A novel method for measuring the dynamical deformation is proposed by using of high speed digital image correlation in high temperature environment. The nature texture of ceramic materials can be used as speckle while filters and monochrome produced by LED are applied to suppress black-body radiation and enhance the luminous intensity.

The light from the heated material can alter the Grayscale of material surface and the recognition for material surface will become more and more difficult with the temperature increase. In… More >

Hong Miao, Chong Yang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 113-114, 2011, DOI:10.3970/icces.2011.020.113

Abstract An experimental measurement system of digital holographic interferometry is established. The sequence of holograms during the dynamic deformation of a specimen can be captured by the CCD camera continuously. These holograms are reconstructed by a 2D Fourier transform and subsequently the phase difference values between any instant and initial instant can be calculated. The original phase sequence is full of noise in both spatial and temporal domains. A windowed Fourier filtering can be employed to remove the noise and retrieve the clear phase distribution. A further windowed Fourier ridges processing makes it possible to evaluate the first-order derivative and second-order… More >

Jiang Ming, He Xiaoyuan

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.4, pp. 111-112, 2011, DOI:10.3970/icces.2011.020.111

Abstract Fast-starts are brief, sudden accelerations used by fish during predator-prey encounters. In this paper, a three-dimensional (3D) test and analysis method is critical to understand the function of the pectoral fin during maneuvers. An experiment method based on Fourier Transform Profilometry for 3D pectoral fin profile variety during fish maneuvers is proposed. This method was used in a carp fast-start during prey. Projecting the moirAC fringes onto a carp pectoral fin it will produce the deformed fringe patterns contain 3D information. A high speed camera captures these time-sequence images. By Fourier transform, filter, inverse Fourier transform and unwrap these phase… More >