• The Bulletin of The Korean Astronomical Society
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• v.30 no.2
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• pp.72.1-72.1
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• 2005

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2003.04a
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• pp.112-117
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• 2003

• Proceedings of the Optical Society of Korea Conference
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• 1997.08a
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• pp.25-25
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• 1997

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.2
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• pp.137-147
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• 2008

A reliability analysis has been performed to investigate the systematic stability of multi-failure modes of rubble-mound breakwaters. The reliability functions of four different failure modes are established straightforwardly. AFDA(Approximate Full Distribution Approcah) reliability models for each failure modes are directly developed and satisfactorily calibrated through the comparison with CIAD's results. In the reliability analysis of single failure mode, the probabilities of failure are calculated and the influence coefficients of random variables in the failure modes are properly evaluated. Meanwhile, three different models such as uni-modal bounds, bimodal bounds, and PNET are applied to evaluate the probabilities of failure of multi-failure modes for rubble-mound breakwaters. It may be found that uni-modal bounds tend to overestimate the probability of failure of multi-failure modes. Therefore, for the systematic reliability analysis of multi-failure modes, it is recommended to use bi-modal bounds or PNET which consider the correlation between the failure modes for rubble-mound breakwaters. By introducing the reliability analysis of multi-failure modes, it could be possible to find out the additional probabilities of failure occurred by the multi-failure modes of a multi-component system such as rubble-mound breakwaters.

• Fire Science and Engineering
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• v.12 no.1
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• pp.3-8
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• 1998

This study has been conducted experimentally on the effects of natural convection heat transfer characteristics for inclined flat plate with vertical fin in air. The effects of various fin length, flat plate inclined angle and Grashof number are mainly investigated The experimented results are as follows: The mean heat transfer coefficient increase according to the decrease of H/S in the various fin lengh. The mean heat transfer coefficient at H/S-0.5, 1.0, 1.5 for Gr=2.11$\times$103. $\theta$=00 increase by 107%, 43%, 15% than H/S=2.0. The mean heat transfer coefficient decrease with the increase of $\theta$ the inclined angles. The mean heat transfer coefficient at Gr=2.97$\times$103 is constant, at $\theta$= 00 for H/S=0.5 decrease by 33% than $\theta$=90$^{\circ}$. The mean heat transfer coefficient increase as Grashof as Grashof number increase. The mean heat transfer coefficient at Gr=2.31$\times$103, Gr=2.61$\times$103, Gr=2.97$\times$103 for H/S=1.0, $\theta$=0$^{\circ}$increase by 9%, 16%, 28% than Gr=2.11$\times$103.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.1
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• pp.50-56
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• 2008

In this paper, a digital inclinometer to measure the angle and acceleration signals of subject laid on Roll was designed. The designed system consists of a tilt sensor, biaxial accelerometer, single chip microprocessor and Bluetooth module. The designed digital inclinometer was easy to handle and to wear. To evaluate the performance of the system, we measured simultaneously the angle and acceleration signals from the 3 subjects on the Roll using two instruments which are ZEBRIS and designed system. The measured signals were processed by statistical method and then the correlation coefficient of 0.93 was shown. From the results, the designed digital inclinometer is shown to be useful in assessment of body movement.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.1
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• pp.89-96
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• 2008

The study, with regard to unsymmetrically inclined backfilled wall, was intended to estimate the lateral earth pressure, develop the equation for lateral earth pressure and eventually identify the mutual behavior, based on the modified Kellogg theory, while changing the width between the walls, wall angle, relative density and wall friction angle. To verify the geostatic pressure obtained from the study, the results in the wake of 62 kinds of model tests performed were compared and evaluated with the behaviors based on theoretical equations. As a result, the wall inclination angle was found to be the factors affecting the earth pressure the most, when both walls were inclined unsymmetrically. And the narrower the backfill space and the larger the wall inclination angle to the horizontal level, the greater the effect of the wall friction. The equation considering the wall friction reaction indicated the value, which was closer to the actually-measured earth pressure, and when the width between the warts was narrow, the arching effect appeared to be great, thereby indicating the difference between the measured earth pressure, theoretically calculated earth pressure and the geostatic pressure proved to be insignificant.

• Resources Recycling
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• v.5 no.3
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• pp.37-43
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• 1996

The recovery of metals from printed circuit board(PCBs) scraps was investigated by utilizing a shape sorting method.After all electronic parts mounted on the board were removed. PCBs were pulverized to particles smaller than 1 mm by aswing hammer type impact mill in order to liberate metal components. Metals were separated from nonmetalliccomponents by an inclined vibrating plate (IVP). The metal separation efficiency was measured as a function of vihrationintensity and inclined angle. The maximum efficiency was obtained when IVP was operated at the vibration intensity(Kv)of 1.40 and the inclined angle of 10". The grade of the metal components was recovered from PCBs exceeding 90% byusing IVP.0% by using IVP.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.404-404
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• 2021

기후변화에 따른 물 순환과정의 변화는 유역내 강우패턴 및 강우강도, 유출 특성에 큰 영향을 미친다. 유역내 강우패턴 및 강우강도 등 물 순환과정의 변화는 강우에 의한 유출과 밀접한 관련이 있는 비점오염원에 중대한 영향을 미친다. 특히, 고랭지밭에 밀집되어 있어 강우에 따른 토사로 인한 탁수가 빈번하게 문제가 되고 있는 소양호 유역은 비점오염원관리지역으로 지정되어 탁수를 저감하기 위해 많은 노력을 기울이고 있는 실정이다. 이러한 노력들 중 환경부에서는 개별 경작지마다 BMPs(Best Management Practices)를 적용하여 강우에 의한 탁수를 저감하고자 하였으며, 앞으로도 지속적으로 설치할 계획에 있다. 그러나 이러한 비점오염저감시설을 적용하였을 때의 저감효율은 밭의 면적이나 경사도, 경사장 등 다양한 조건을 고려해야 하는 어려움이 있어, 이에 대한 연구는 매우 제한적으로 이루어져 왔다. 이에 따라, 각 경작지에 적용된 개별 비점오염저감시설이 유역 말단에 미치는 영향에 대한 연구 역시 미비한 실정이다. 그러나 비점오염저감대책 및 계획은 유역 말단을 기준으로 하는 경우가 많고, 유량 및 수질에 대한 모니터링 자료 역시 유역 말단에 위치하기 때문에 개별 비점오염저감시설이 유역 말단에 미치는 영향에 대한 연구는 매우 중요하다고 할 수 있다. 따라서 본 연구에서는 유역단위 평가모델 중 하나인 SWAT을 이용하여 각 경작지 별로 실측 경사장 및 경사도, 개별 비점오염저감시설을 적용하였으며, 개별 비점오염저감시설이 유역말단에 미치는 영향을 평가하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.1
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• pp.171-181
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• 2001

Recently, the development of CNC machine tools seems to bring about progressional high speed, precision and automation in cutting processing, but is unlikely to avoid the generation of burr arising from plastic deformation, which may result in deterioration of improvement in the precision and productivty of products. In this study, Experiment has been carried out to prevent and decrease the grinding burr under various working conditions ; working speed, side cutting edge, back rake angle, disengage angel.