• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1000-1005
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• 2010

국내에 대표적인 표면파 탐사법인 MASW, SASW, HWAW를 비교한 결과에 따르면, 세기법들의 결과가 매우 유사하게 도출되는 것을 확인할 수 있었으나, 각 현장별로 획득한 탐사심도의 차이가 존재하였다. 넓은 시험 측선을 필요로 하는 SASW 및 MASW 기법의 경우 현장 상황 및 조건에 따라 15m 정도의 얕은 심도의 물성만을 획득하였다. 표면파 기법은 토사층에서는 매우 신뢰성있는 결과를 도출하였으며 2차원 영상화를 통한 넓은 영역의 물성치를 빠르고 경제적으로 획득할 수 있는 장점이 있다. 현재 지반조사 시 소수의 시추자료를 이용하여 부지의 특성을 파악하기 때문에 시추공간 물성치 및 지반구조에 대해서 확실한 파악이 이뤄지지 않고 있기 때문에 표면파 기법은 토사층의 물성산출 뿐만 아니라 시추공탐사법을 보완하여 시추공간 물성변화를 파악하는 유용한 시험법이라고 판단된다.

• 한국지구물리탐사학회:학술대회논문집
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• 2008.10a
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• pp.101-106
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• 2008

It is very important to measure reliable properties of each zones in dam for seismic design. But, rock-fill zone which have 80% of total volume and support maintenance mainly during earthquake has little property by field test and seismic design was performed using assumed value. So, it is required that reliable properties have to be evaluated by in-situ test. In this study, surface wave method, which is nondestructive such as SASW and HWAW, was applied to dam to evaluate rock-fill zone of dam. In 2 dams, Vs profiles were evaluated reliably and possibility of suggestion of D/B was verified.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.69-85
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• 2009

It is very important to measure reliable dynamic properties of each zone in dam for seismic design. However, the Vs values of core and rock-fill zone are seldom determined by field test. Consequently, seismic design in dam is performed using Vs values assumed or empirically determined. So, it is required that reliable Vs has to be evaluated by in-situ test. In this study, surface wave method, which is nondestructive, was applied to dam to evaluate Vs profiles of core and rock-fill zone in dam. In 6 dams, using SASW and HWAW methods, Vs profiles were evaluated reliably. D/B of Vs profiles of each zone with depth and relationship between confining pressure and Vs profiles of rock-fill zone were constructed including existing results of other dams. The evaluated D/B and proposed relationship were compared with the frequently used empirical method by Sawada and Takahashi.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.174-178
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• 2011

This paper deals with the free cooling system of express bus using natural energy source in order to improve the room air quality and save cooling energy. In an express bus, there are may passengers in unit area, requiring the improvement of air quality and giving higher energy saving efficiency. Particularly, the express buses running fast make it easy to take in outdoor air at a flow rate controllable with a damper mechanism. This paper proposes the analysis on the air flow achieved by a damper controlled vertically and horizontally in order not to deteriorate the ride comfort of the passengers.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.209-218
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• 2009

In this study, properties of shear wave velocity of core zone in filldams are analyzed. Shear wave velocity is derived using analysis of surface wave method that can be used nondestructively on the surface of filldams. These values are acquired through the tests for the core zone of six filldams by SASW and HWAW methods. Existing 2 more results are added. Shear wave velocity according to the depth and confining pressure are estimated, respectively. These analytical results are compared with the frequently used empirical method by Sawada and Takahashi.

• Journal of the Korean Geotechnical Society
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• v.36 no.4
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• pp.31-39
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• 2020

Shear wave velocity (or shear modulus) is very important in the evaluation of seismic performance of a fill dam under an earthquake. A shear wave velocity profile can be determined by surface wave method such as HWAW and SASW methods but this profile has uncertainty caused by spatial variation of material property in a fill dam. This uncertainty in shear wave velocity profile could be considered using a coefficient of variation of material property in the reliability based analysis. In this paper, the possible 600 shear wave velocity profiles in the core and rockfill zone of fill dam were generated by the random shear wave velocity profile generation method, proposed by Hwang and Park, based on the field shear wave velocity profiles determined by the HWAW and SASW methods. And, through the statistical analysis of generated shear wave velocity profiles in the fill dam, the coefficient of variation (COV) of shear wave velocity with depth were evaluated for the core and rock filled zone of fill dam in Korea.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.311-312
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• 2022

본 논문에서는 날씨가 더울 때, 가만히 있어도 땀이 주륵주륵 흐른다. 본격적인 더위가 시작되면 여름철 많은 곳에서 에어컨과 선풍기와 같은 가전제품을 사용한다. 이러한 제품들은 낮 시간뿐만이 아니라 수면 시에도 장시간 사용이 되는데, 특히 선풍기를 주로 사용했을 때, 이미 체온이 일정 온도로 떨어졌음에도 불구하고 지속적으로 사용이 된다면, 전력 낭비뿐만이 아니라, 선풍기에서 열이 발생하여 자칫 화재가 일어날 수도 있다. 이러한 문제를 막기 위해서 수면 중이나 일상생활을 하는 동안에 지정해 놓은 실내온도로 떨어질 경우 자동으로 정지하고, 지정해 놓은 온도 이상으로 실내온도가 올라갈 경우에는 다시 작동하는 선풍기를 개발하면 효율적으로 사용할 수 있다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.443-444
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• 2022

본 논문에서는 스타일러는 옷을 빨거나 다리지 않고도 마치 새옷처럼 다시 입을 수 있도록 관리해준다는 콘셉트로 등장한 의류기기이다. 출시 당시에는 생소하고 크기가 커서 큰 호응을 얻지 못했지만, 최근에는 작고 편리한 신제품을 내놓으면서 대중화 시대를 열어가고 있다. 양복을 주로 입는 회사원에서 싱글족까지 스타일러를 사용하고 있지만 대중적인 스타일러는 정해진 위치에서만 사용해야 한다는 불편함이 있다. 또한 출장이 잦은 직업이나 먼지가 많은 공간에서 일하는 직업의 경우 옷에 주름이나 먼지를 제거하지 못해 구겨진 옷을 입고 다니는 경우가 많다. 그래서 우리는 가정용 스타일러에서 장소에 구애받지 않고 사용할 수 있는 휴대용 스마트 스타일러를 제작하기로 하였다. 예기치 못한 상황에서의 중요한 자리가 있을 때 휴대용 스타일러가 있다면 준비해둔 의류를 상황에 맞춰 관리하여 다닐 수 있을 것이며, 스타일러에 온도와 습도를 보여주는 기능이 있다면 스타일러를 사용하기 전에 스타일러의 상태가 양호한지 판단할 수 있을 것이다.

• Journal of the Korean Geotechnical Society
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• v.33 no.4
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• pp.17-24
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• 2017

Shear wave velocity (or shear modulus) of rock filled zone of CFRD is very important factor in the evaluation of performance of CFRD under the load such as earthquake. A shear wave velocity profile can be determined by surface wave method but this profile has been uncertainty caused by spatial variation of material property in rock filled zone. This uncertainty in shear wave velocity profile could be evaluated by the reliability based analysis which uses a coefficient of variation of material property to consider uncertainty caused by spatial variation of material property. In this paper, the possible 600 shear wave velocity profiles in rock filled zone of CFRD were generated using the method based on harmonic wavelet transform and 8 shear wave velocity profiles by HWAW method in the field, and the coefficients of variation of shear wave velocity with depth were evaluated for the rock filled zone of CFRD in Korea.

• 한국태양에너지학회:학술대회논문집
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• 2011.04a
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• pp.269-274
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• 2011

A solar cell is primary parts to produce electrical energy from the Sun. And, we can utilize those solar cells as a power generation system in home, factory, and so on. In order to make proper power, the solar cells are configured in series and parallel lay down. In condition of uniform illumination, the solar array will produce an enough power by photovoltaic effects from the solar cells. In case of non-uniform illumination on the solar cells, the power will be dramatically decreased compared to design. Fortunately, there were so many research outputs regarding the illumination effects on solar array. In this work, we tried to find out the non-uniform effects on unit CPV solar cell, because there were no research outputs for unit CPV solar cell considering illumination. The CPV solar cell was used in CPV system to make a power by the Sun. We chosen the triple junction solar cell of GaAsInP2Ge for simulation, which has a 30 % of conversion efficiency. By simulation, we obtained the output performance of CPV solar cells in condition of various illumination by using Hamming Window function. Its performance was degraded by 10 % to 50 % depending illumination conditions.