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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Nondestructive Testing
Journal Basic Information
Journal DOI :
The Korean Society for Nondestructive Testing
Editor in Chief :
Volume & Issues
Volume 25, Issue 6 - Dec 2005
Volume 25, Issue 5 - Oct 2005
Volume 25, Issue 4 - Aug 2005
Volume 25, Issue 3 - Jun 2005
Volume 25, Issue 2 - Apr 2005
Volume 25, Issue 1 - Feb 2005
Selecting the target year
Measurement of Thickness Distribution of
Membrane Using Phase-Shifting Interferometer
Lee, Jung-Hyun ; Jeong, Seung-Jun ; Kang, Jeon-Woong ; Jeon, Yun-Seong ; Hong, Chung-Ki ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 67~73
The thickness of a Si3N4 thin film with a 100m nominal thickness was measured by use of a Mach-Zehnder interferometer. The map of the phase-delay through the thin film was obtained by an interframe intensity-correlation-matrix method that could elliminate phase-shifting errors. After the spatial phase-shifting errors were treated with a least-squares method, the reference to surface of the phase map was estimated. The overall accuracy of the method was found to be 5nm.
A Study on Adaptable Non-contact Shape Inspection System
Kang, Young-June ; Park, Nak-Gyu ; Lee, Dong-Hwan ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 74~80
A new dimension measuring method for the measurement of diameter of an object has been developed using laser triangulation. The 3D data of an object was calculated from the 2 dimensional image information obtained by the laser stripe using the laser triangulation. The system that use existing theory can measure the diameter of hole not only in a normal plane but also ill an incline plane. However, in the existing theory, since the lens with fixed feral length was used, the area of measurement was fixed. The simplest way to solve this problem is to change distance between a CCD camera and object. Other way is to use a zoom lens having variable focal length. In this paper, the zoom lens with variable focal length was used. Therefore, we ran experiment with magnification that is optimized according to size of object using zoom lens with variable focal length.
Non-destructive Inspection of Semiconductor Package by Laser Speckle Interferometry
Kim, Koung-Suk ; Yang, Kwang-Young ; Kang, Ki-Soo ; Choi, Jung-Gu ; Lee, Hang-Seo ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 81~86
This paper proposes a non-destructive ESPI technique to quantitatively evaluate defects inside a semiconductor package. The inspection system consists of the ESPI system, a thermal loading system and an adiabatic chamber. The technique is high feasibility for non-destructive testing of a semiconductor and overcomes the weaknesses of previous techniques, such as time-consumption and difficult quantitative evaluation. Most defects are classified as delamination defects, resulting from the insufficient adhesive strength between layers and from non-homogeneous heat spread. Ninety percent of the tested samples had delamination defects which originated at the corner of the chip and nay be related to heat spread design.
Arrayed-Arc Slit Design to Improve the focusing Effect of the focused Lamb Wave by Laser
Jhang, Kyung-Young ; Kim, Hong-Joon ; Sin, Min-Jea ; Kim, Jae-Yeol ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 87~94
In recent, Lamb wave has been actively studied for non-destructive testing of plate. Among those studios, laser generation method of focused Lamb wave is expected to have high spatial resolution with advantages of non-contact testing. In this method, the laser beam is illuminated on the surface of object by through an arrayed-arc slit, and then the energy of the generated Lamb wave is concentrated at a focus of arc. This focusing effect improves the spatial resolution, which is dependant on the geometries of arrayed-arc slit. In this paper, the relationships between the parameters of arc-shaped slit and the focusing ability of the generated Lamb wave was investigated by the simulation based parametric study The results show that to improve the focusing effect, radius of illuminated laser, angle of arc and number of arcs must be increased, which minimum radius of arc and distance between arcs(=wavelength) must be decreased. These results are expected to be used as a guide to design the proper shape of slit.
Application of Laser-based Ultrasonic Technique for Evaluation of Corrosion and Defects in Pipeline
Choi, Sang-Woo ; Lee, Joon-Hyun ; Cho, Youn-Ho ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 95~102
There are many tube and pipeline in nuclear power plant under high temperature and high pressure. Erosion and corrosion defects were expected on these tube and pipe-line by environmental and mechanical factors. These erosion and corrosion defects ran be evaluated by ultrasonic technique. In these study, Scanning Laser Source(SLS) technique was applied to detect defect and construct image. This technique also makes detection possible on rough and curved surfaces such as tube and pipe-line by scanning. Conventional ultrasonic scanning technique requires immersion of specimen or water jet for transferring ultrasonic wave between transducer and specimen. However, this SLS technique does not need contacting and couplant to generate surface wave and to get flaw images. Therefore, this SLS technique has several advantages, for complicated production inspection, non-contact, remote from specimen, and high resolution. In this study, SLS images were obtained with various conditions of generation laser ultrasound and receiving in order to enhance detectability of flaws on the tube. Stress corrosion cracks were produced on tube and images of stress corrosion cracks were constructed by using SLS technique.
A Study on Nondestructive Technique Using Laser Technique for Evaluation of Carbon fiber Reinforced Plastic
Choi, Sang-Woo ; Lee, Joon-Hyun ; Byun, Joon-Hyung ; Seo, Kyeong-Cheol ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 103~109
Fiber reinforced plastic material should be inspected in fabrication process in order to enhance quality by prevent defects such as delamination and void. Generally, ultrasonic technique is widely used to evaluate FRP. In conventional ultrasonic techniques, transducer should be contacted on FRP. However, conventional contacting method could not be applied in fabrication process and novel non-contact evaluating technique was required. Laser-based ultrasonic technique was tried to evaluate CFRP plate. Laser-based ultrasonic waves propagated on CFRP were received with various transducers such as accelerometer and AE sensor in order to evaluate the properties of waves due to the variation of frequency. Velocities of laser-based ultrasonic waves were evaluated for various fiber orientation. In addition, laser interferometry was used to receive ultrasonic wave in CFRP and frequency was analysed.
A Study on the Estimation of Object's Dimension based on the Vision System Model of Extended Kalman filtering
Jang, W.S. ; Ahn, H.C. ; Kim, K.S. ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 110~116
It is very important to reduce the computational processing time for the application of the vision system in real time such as inspection, the determination of object's dimension and welding etc, because the vision system model involves a lot of measurement data acquired by CCD camera. Also, a lot of computation time is required in estimating the parameters in the vision system model if the iterative batch estimation method such as Newton Raphson is used. Thus, the effective computation method such as the Extended Kalman Filtering(EKF) is required to solve the above problems. The EKF has much advantages in that it takes explicitly into account the measurement uncertainties, and is a simple and efficient recursive procedures. Thus, this study is to develop the EKF algorithm to compute the parameters in the vision system model in real time. This vision system model involves the six parameters to account for the cameras inner and outer parameters. Also the EKF is applied to estimate the object's dimension. Finally, practicality of the estimation scheme of the vision system based on the EKF is verified experimently by performing the estimation of object's dimension.
Study on Point Defect for
Single Crystal Thin film Obtained by Photoluminescience Measurement Method
Hong, Kwang-Joon ; Kim, Koung-Suk ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 117~126
A stoichiometric mixture of evaporating materials for
single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films,
mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were
, respectively The temperature dependence of the energy band gap of the
obtained from the absorption spectra was well described by the Varshni's relation,
. After the as-grown
, single crystal thin films was annealed in Ag-, S-, and Ga-atmospheres, the origin of point defects of
single crystal thin films has been investigated by the photoluminescence(PL) at 10K. The native defects of
, obtained by PL measurements were classified as a donors or acceptors type. And we concluded that the heat-treatment in the Ag-atmosphere converted
single crystal thin films to an optical n-type. Also, we confirmed that Ga in
crystal thin films did not form the native defects because Ga in
single crystal thin films existed in the form of stable bonds.
The Evaluation on the frequency Characteristics of the Optical Glass Lens by Resonant Ultrasound Spectroscopy
Yang, In-Young ; Kim, Seung-Hoon ;
Journal of the Korean Society for Nondestructive Testing, volume 25, issue 2, 2005, Pages 127~132
The optical glass lens is required high dimensional precision such as the lack of defect. In this paper, we examined the detectable defect by using the resonant ultrasound spectroscopy(RUS). The RUS is the measurement system which is to excite the specimen and to inspect the differences of resonant frequency pattern between acceptable specimen and specimen which has some defects. In this paper, for nondestructive evaluation by using RUS, we measured the resonant frequency of each specimen which is spherical and aspherical glass lens. With the results, we knew the polishing processing degree of spherical glass lens by the measured resonant frequency and could evaluate the characteristic of aspherical glass lens about some flaws.