• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.309-315
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• 2001

The Stress intensity factors for edge cracks located at the bonding interface between the elastic semiconductor chip and the viscoelastic adhesive layer have been investigated. Such cracks might be generated due to stress singularity in the vicinity of the free surface. The domain boundary element method(BEM) has been employed to investigate the behavior of interface stresses. The overall stress intensity factor for the case of a small interfacial edge crack has been computed. The magnitude of stress intensity factors decrease with time due to viscoelastic relaxation.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.1
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• pp.53-64
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• 2000

Strain gage method is investigated to evaluate the mode I stress intensity factor. Two types of specimens for CT and three point bend specimen are used. Sharp notch of specimens is manufactured by wiring discharge machining. Strain gages signal from the crack tip region are used to calculate stress intensity factors. The results are compared with those of the ASTM E399 method and finite element analysis. The present experimental results coincide well with the data obtained from finite element analysis. Attached position of strain gage should be seriously considered during the application of this method.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.1
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• pp.66-74
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• 2002

Warranty cost analysis for one-dimensional warranties assumes that the usage intensity (or rate) is the same for all buyers. In real life the usage intensity varies across the population of buyers. Also for products sold with warranty, preventive maintenance actions by manufacturers and buyers have a significant impact on the total costs for both parties. In this paper we deals with models to study the expected warranty cost for products with free repairable warranty with varying usage intensity and three types of preventive maintenance. We also review the literature which links warranty and maintenance and develops a framework to define new topics for research in the future and examines a new model formulation. It then develops a new model and carries out its analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.647-653
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• 2011

In this study, a method to measure the thickness of thin film by EDS (energy dispersive spectroscopy) is suggested. We have developed a model which calculates the thickness of thin film from the characteristic x-ray intensity ratio of the elements in thin film and substrate by considering incident electron beam energy, x-ray generation curve, backscattering and absorption of x-ray, take-off angle of x-ray and tilt angle of the sample. We obtained the relation curve between the film thickness measured experimentally and the x-ray intensity ratio of elements. The film thicknesses calculated from the model agrees quite well with those measured experimentally. Therefore, the thin film thickness can be measured rapidly and accurately by using the model developed in this study and the x-ray intensity ratio obtained in EDS analysis.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.12
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• pp.1270-1277
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• 2008

For designing intensity modulation type optical microphone, the irradiance distribution which can be applied to inclined-cut geometrical configuration is suggested. The model is important in analysis of response characteristics for intensity modulation type optical microphone. To overcome low sensitivity problem in intensity modulation type optical microphone, inclined-cut optical fiber is considered here. Based on optical geometry, the inclined-cut optical fiber sensor is designed and fabricated. The experiments are carried out to evaluate sensor performance.

• Korean Journal of Remote Sensing
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• v.11 no.2
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• pp.29-42
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• 1995

A typhoon center location and its intensity from the 54.96GMz channel of Microwave Sounding Unit(MSU) on board the NOAA satellite is analyzed. NOAA satellite MSU channel 3 data may delineate the development and dissipation of the upper tropospheric warm core associated with a typhoon. The typhoon warm core is related to microwave imagery of 250hPa temperature field (54.96GMz). The typhoon center intensity, surface center pressure and maximum wind speed at the eye well, correlate to horozontal Laplacian of an upper tropospheric temperature field. The typhoon center is found from the analysis of 250hPa temperature field. The excellent correlation is found between the horizontal Laplacian of an tropospheric temperature field and surface maximum wind speed, another correlation is found between the warm temperature anomaly and surface pressure anomaly.

• Steel and Composite Structures
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• v.25 no.2
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• pp.209-216
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• 2017

In this paper, the analysis of the behavior of surface cracks in finite-thickness plates repaired with a Boron/Epoxy composite patch is investigated using three-dimensional finite element methods. The stress intensity factor at the crack-front was used as the fracture criteria. Using the Ansys Parametric Design Language (APDL), the stress intensities at the internal and external positions of repaired surface crack were compared. The effects of the mechanical and geometrical properties of the adhesive layer and the composite patch on the variation of the stress intensity factor at the crack-front were examined.

• Journal of The Korean Astronomical Society
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• v.29 no.spc1
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• pp.217-218
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• 1996

The results of the Crab pulsar observations with the photometrical MANIA (Multichannel Analysis of Nanosecond Intensity Alterations) complex at the 6-m telescope are presented. More than 12 millions photons in UBVR-bands simultaneously with time resolution of $10^{-7}s$ were detected. Using the original software for search for optical pulsar period, we obtained the light curves of the object with time resolution of about 3.3 ${\mu}s$. Their detailed analysis gives the spectral change during pulse and subpulse, the shape of the pulse peaks, which are plateaus (with the duration of about 50${\mu}s$ for the main pulse), limits for an amplitude of fine temporal (stochastic and regular) structure of pulse and sub pulse and the interpulse space intensity. The results of CCD-spectroscopy of the Crab pulsar show that its summarized spectrum is flat. There are no lines, neither emission nor absorbtion ones. Upper limit for line intensity or depth is $3.5\%$ with the confidence probability of $95\%$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.7
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• pp.1120-1131
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• 2003

A recently developed numerical method based on a mixed volume and boundary integral equation method is applied to calculate the accurate stress intensity factors at the crack tips in unbounded isotropic solids in the presence of multiple anisotropic inclusions and cracks subject to external loads. Firstly, it should be noted that this newly developed numerical method does not require the Green's function for anisotropic inclusions to solve this class of problems since only Green's function for the unbounded isotropic matrix is involved in their formulation for the analysis. Secondly, this method takes full advantage of the capabilities developed in FEM and BIEM. In this paper, a detailed analysis of the stress intensity factors are carried out for an unbounded isotropic matrix containing an orthotropic cylindrical inclusion and a crack. The accuracy and effectiveness of the new method are examined through comparison with results obtained from analytical method and volume integral equation method. It is demonstrated that this new method is very accurate and effective for solving plane elastostatic problems in unbounded solids containing anisotropic inclusions and cracks.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.380-385
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• 2016

Shadows are common phenomena observed in natural scenes and often bring a major problem that is affected negatively in colour image analysis. It is important to detect the shadow areas and should be considered in the pre-processing of computer vision. In this paper, the method of shadow detection is proposed using cross entropy and intensity image, and is performed in single image based on the satellite images. After converting the color image to a gray level image, the shadow candidate region has been estimated the optimal threshold value by cross entropy, and then the final shadow region has been detected using intensity image. For the validity of the proposed method, the satellite images is used to experiment. Some experiments are conducted so as to verify the proposed method, and as a result, shadow detection is well performed.