• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.93-105
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• 2000

일정변형률압밀사시험의 효율성 및 적용성을 구체화하기 위해 인공시료 또는 한정된 지역에서 채취한 불교란 점성토 시료가 아닌 광범위한 지역에서 채취한 불교란 점성토 시료에 대해 시험을 실시하였다. 시료채취의 대상지역은 우리나라의 서해안에서 동해안에 이르는 13개 지역이며, 29개의 불교란 자연시료를 채취하여 일정변형률압밀시험을 113회 실시하였다. 또한, 비교하기 위해 표준압밀시험도 병행하였다. 시험결과로부터 얻어진 압밀정수에 대한 공학적 특성을 고찰하였고, 회기분석을 통해 통계식을 제안하였다. 두 시험법에 의해 산출된 압밀정수를 비교 분석한 결과 수압비가 20% 이내인 범위에서는 일정변형률압밀시험의 변형률 속도가 압밀시험의 정수에 미치는 영향은 거의 없는 것으로 나타났다. 압축지수 및 압밀계수는 일정면형률시험의 결과 값이 표준압밀시험의 결과 값보다 크게 산출되었으나 일관성을 보였다. 또한, 선행압밀압력에 있어서는 두 시험법에 Cassagrande의 방법을 적용할 경우 서로 일치하는 것으로 나타났다. 본 연구로부터 일정변형률압밀시험을 사용하여 표준압밀시험에 상용하는 상호관계식 개발의 타당성을 확인할 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.425-428
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• 2000

본 논문에서는 영동산 일라이트가 갖는 기능성을 이용하여 정수기용 필터로써의 가능성을 검토한다. 대장균 실험을 통하여 항균성을 평가하였고, 여러 가지 중금속(Zn, Pb, Cu, Cd, Fe$^{2+}$)의 흡착능력을 평가하였다 정수기 필터재료로 사용하기 위한 성형조건을 실험하였고, 물 필터하우징에 성형된 illite ceramic을 충진하여 물을 정수 처리하여 버섯 재배에 적용하였다. 결과적으로 항균성은 white-yellow-red 순이었고 중금속흡착능력은 원소에 따라서 yellow가 white보다 크게 나타났고, 이에 착안하여 버섯재배에 적용한 결과 수율 향상에 크게 기여하는 것으로 나타났다. 본 논문에서 illite ceramic이 필터재료로서의 가능성을 나타내고 이를 개발, 보고 하고자 한다.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.313-314
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• 2017

본 논문에서는 부천시 핵심 국가기반시설로서 부천시민의 삶의 질에 가장 큰 영향을 끼치는 요인인 수돗물 공급서비스의 위험요인를 파악하고 이를 해소하는 방안을 마련하며, 국제 및 국내적으로 테러의 위험이 높아가고 있는 가운데 재난대비역량을 강화하여 시민이 수돗물을 안심하고 이용할 수 있도록 수돗물 공급역량 강화 방안을 마련하였다. 본 논문에서는 팔당댐 수원지에서 부천시 정수장까지 원수 공급 과정부터 정수장내 취수/정수/배수과정을 거쳐 소비자에게 공급하는 전과정에서 위험요인과 개선방안을 도출하였으며 향후계획 수립 방향을 제시하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.146-149
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• 1998

우리 나라는 1994년 말 현재 654개소에 28,434개소의 수도사업체가 있으며, 이중 간이상수도는 26,363개소로 총 93%를 차지하고 있다. 간이상수도와 같은 소규모 수도사업체에서는 재정적인 기반이 취약하며, 기술자 등이 인재확보가 어려운 형편이다. 이에 따라 대부분의 경우 수도시설의 일상적인 유지관리에 많은 불편이 따르고 있을 뿐만 아니라 적정 수질을 확보하기가 곤란한 실정이다. 간이상수도에서 수질이 좋은 물을 효율적으로 공급하기 위해서는 기존의 정수처리 시스템으로는 어려운 형편이다. 즉, 우리 나라 간이상수도의 정수처리과정은 소독을 기본으로 하여 응집침전, 급속모래여과, 등의 고액분리조작을 주체로 하고 있어 각 과정에 대한 유지관리에 많은 노력이 필요하다. 이에 따라 간이상수도에서는 보다 효율적으로 수질관리가 이루어질 수 있는 장치 및 시스템의 개발이 절실하다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.16 no.4
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• pp.191-195
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• 2004

This study investigated the effect of deep-sea environment on the compressive characteristics of polymer matrix composite. The specimens used in the experiment were thick Carbon-Epoxy composites that were made from Carbon-Epoxy prepregs. The specimens were immersed into seawater for thirteen months. The seawater content at saturation was about 1.2% of the specimen weight. The hydrostatic pressures applied were 0.1 MPa, 100 MPa, 200 MPa, and 270 MPa. It was found that the compressive elastic modulus increased about 10% as the hydrostatic pressure increased from 0.1 MPa to 200 MPa. The modulus increased additional 2.3％ as the pressure increased to 270 MPa. It was also found that compressive fracture strength and compressive fracture strain increased with pressure in a linear behavior. Compressive fracture strength increased 28％ and compressive fracture strain increased 8.5％ as the hydrostatic pressure increased from 0.1 MPa to 270 MPa.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.1
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• pp.125-130
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• 2007

Single-phase is used widely power of field of appliance because can use commercialized power directly without power transform. Specially, because condenser nu-drive style single-phase induction motor efficiency is excellent, and most suitable in embodiment as economical. It is established true that method by crossing self-discipline and method by revolving magnetic field are interpretation of net single-phase induction motor, but method to calculate electric motor inside proper move in existent theory or method is some complex. That arbor in the law of circuit constant that combine equivalent circuit law with numerical analysis law according to development of the latest computer or microprocessor is suggested and does the calculation processing fast and correct. In this paper, measurement wishes to present method that calculate after calculate digital measurement that measures correctly and measures impossible the first and the second leakage reactance and no-load test locked-rotor test, DC test and resistance measurement of stator winding in circuit parameter calculation program that is had for MatLab program individually in single-phase power.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.592-598
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• 2008

In this paper, a novel pilot-aided integer frequency offset estimation scheme is proposed for orthogonal Sequency division multiplexing (OFDM)-based digital video broadcasting (DVB) systems. The conventional pilot-aided integer frequency offset estimation scheme proposed for OFDM-based DVB systems exploits the partial information of combinations provided by pilots. Thus, in this paper, we propose a novel integer frequency offset estimation scheme exploiting all information of pilot combinations. To compare the performance of the proposed scheme with that of the conventional scheme, we conduct a simulation in additive white Gaussian noise (AWGN) and multipath Rayleigh channels, which shows that the proposed scheme outperforms the conventional scheme in terms of the probability of integer frequency offset estimation failure.

• Journal of the Korean Geotechnical Society
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• v.30 no.3
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• pp.73-85
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• 2014

The strength parameters used in rock mass design are mainly estimated by equations using Hoek-Brown failure criterion because the tests to obtain the values are limited and expensive. To estimate the strength parameters, the Hoek-Brown failure criterion should be transformed to the Mohr-Coulomb failure criterion. But the processes are more or less cumbersome due to the several stages including the computation and the analyzing steps. In this study, several rock states of various conditions were modeled and then the strength parameters were estimated using the Hoek-Brown failure criterion. Thereafter by analyzing the results, some charts and equations estimating the strength parameters through only one step or easily in the field using the values of RMC, the uniaxial compressive strength and the rock constant ($m_i$), were suggested. And then the suggested method was compared and discussed with the existing method.

• Journal of the Korean GEO-environmental Society
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• v.14 no.4
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• pp.15-27
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• 2013

In order to plan out the Daegu G membrane filtration water treatment plant, water quantity, water quality and process stability were evaluated using the field pilot-scale tests, during the six months of continuous operation, including low water temperature period. The field model experiments, which were carried out according to the Installation Criteria of Ministry of Environment, consisted of two series : series 1 - water quality verification, and series 2 - membrane process evaluation. The process water quality met all drinking water standards with less than 0.03 NTU. Moreover, process operation showed a stable membrane pressure with 99% of recovery ratio. This shows that the tests were properly designed in terms of the influence of water loading and temperature. In conclusion, the purpose of this study is to establish core technology for advanced drinking water treatment, through on-going accumulation of engineering and construction know-how.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.410-412
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• 2021

Recently, the amount of information and content has increased dramatically. Users can easily obtain recipe through various media. In addition, the water purifier market is growing without a downward trend and demand for more convenient and smart water purifiers are increasing. By using a smart water purifier with application, each individual can improve the quality of the dish by using a certain amount of water that each person prefers. A solenoid valve was used to allow only the amount of water set by individual to flow out and a solenoid valve and smartphones were linked using Bluetooth communication while using smartphone applications developed when setting the amount of water.