• Corrosion Science and Technology
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• 제14권6호
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• pp.301-312
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• 2015

Corrosion of zirconium fuel cladding is known to limit the lifetime and reloading cycles of fuel in nuclear reactors. Oxide layers formed on ZIRLO4^{TM}$ cladding samples, after immersion for 300-hour and 50-day in a simulated primary water chemistry condition ($360^{\circ}C$ and 20 MPa), were analyzed by using the scanning transmission electron microscopy (STEM), in-situ transmission electron microscopy (in-situ TEM) with the focused ion beam (FIB) technique, and X-ray diffraction (XRD). Both samples (immersion for 300 hours and 50 days) revealed the presence of the ZrO sub-oxide phase at the metal/oxide interface and columnar grains developed perpendicularly to the metal/oxide interface. Voids and micro-cracks were also detected near the water/oxide interface, while relatively large lateral cracks were found just above the less advanced metal/oxide interface. Equiaxed grains were mainly observed near the water/oxide interface.

• 인터넷정보학회논문지
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• 제11권4호
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• pp.51-58
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• 2010

본 논문에서는 USN환경에서 수질 모니터링 시스템을 설계함에 있어 센서 데이터를 효율적인 방법으로 전송하기 위한 다양한 시도를 소개한다. 대표적인 방법은 센서노드에서의 센서 매니지먼트와 싱크노드에서의 클러스터링이다. 센서 매니지먼트는 센싱 간격, 데이터 누적, 데이터 전송 등을 총괄적으로 관리하고, 클러스터링은 데이터 마이닝 기술을 접목한 효율적인 전송 데이터의 축약방법이다. 실험을 통해서 제안한 센서 매니지먼트와 클러스터링을 이용한 전송방법이 일반적인 센서 데이터 전송방법에 비해 얼마나 더 효과적인지를 확인할 수 있었다.

• 한국음향학회지
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• 제26권6호
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• pp.286-292
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• 2007

해수연결 배관계에서 발생되는 주요한 소음원은 함 내부 탑재장비의 원활한 작동을 위해 해수를 순환시키는 해수순환 펌프이다. 이러한 펌프에서 발생되는 토널 성분을 가지는 유체전달 소음은 적절한 소음감소기를 통해서 감소되어야 한다. 본 논문에서는 실험적으로 유체전달 소음감소기의 음향 투과손실을 측정하기 위해서 해수연결 배관계의 끝단 반사가 존재하는 경우 배관 내의 음파를 입사파와 투과파로 분리하는 전달함수 기법을 제안하였다. 제작된 소음감소기 시험시편에 대한 이론적 투과손실과 제안된 기법을 통해 측정된 투과손실이 관심 주파수 영역에서 잘 일치함을 확인함으로써 기법의 타당성을 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.993-997
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• 2004

A data error inspection algorithm for wireless digital data communication was developed. Original data converted By wireless digital data error inspection algorithm. Wireless digital data is high possibility to get distortion and lose by noise and barrier on wireless. If the data check damaged and lost at receiver, can't make it clear and can't judge whether this data is right or not. Therefore, by wireless transmission data need the data error inspection algorithm in order to decrease the data distortion and lose and to monitoring the transmission data as real time. This study consists of RF station for wireless transmission, Water Level Meter station for water level measurement and Error inspection algorithm for error check of transmission data. This study is also that investigation and search for error inspection algorithm in order to wireless digital data transmission in condition of the least data's damage and lose. Designed transmitter and receiver with one - chip micro process to protect to swell the volume of circuit. Had designed RF transmitter - receiver station simply by means of ATMEL one - chip micro processing the systems. Used 10mW of the best RF power and 448MHz-449MHz on frequency band which is open to public touse free within the limited power.

• 상하수도학회지
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• 제31권6호
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• pp.511-519
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• 2017

Multi-regional water supply system, which installed for supplying multiple water demands, is characterized by large-sized, long-distance, tree-type layout. This system is vulnerable to long-standing service interruption when a pipe breaks is occurred. In this study, a numerical method is proposed to calculate drainage time that directly affects time of service interruption. To begin with, governing equations are formulated to embed the delayed drainage effect by the friction loss, and to resolve complicated connection of pipelines, which are derived from the continuity and energy equations. The nonlinear hydraulic equations are solved by using explicit time integration method and the Newton-Raphson method. The developed model is verified by comparing the result with analytical solution. Furthermore, the model's applicability is validated by the examples of pipelines in serial, in parallel, and complex layout. Finally, the model is utilized to suggest an appropriate actions to reduce the deviation of draining time in the C transmission line of the B multi-regional water supply system.

• 한국의류산업학회지
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• 제25권1호
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• pp.119-126
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• 2023

This study aimed to determine the effects of relative humidity and fiber properties on the moisture permeability of multilayer systems by measuring water vapor transmission in the overlapping condition of various fabrics. The results confirmed that the property of the fabric in contact with the humid environment affects the moisture permeability. If the layer facing the humid environment is hydrophobic and the layer facing the dry environment is superhydrophobic, water vapor transmission increases by up to 17.8% compared to the opposite conditions. Comparing the correction values of the water vapor transmission reflecting the thickness of the specimen under the multilayer condition showed that permeability was higher when the hydrophilic or hydrophobic layer was facing the humid environment. The opposite was true from the "push-pull" effect of absorption mechanism. In the case of moisture permeability, the more hydrophilic the surface facing the humid environment, the more permeable that water vapor diffuses and passes through. It was concluded that the "pull-push" effect, in which water vapor diffuses widely through the hydrophilic facing a humid environment and then passes through the hydrophobic layer, contributes to the improvement of permeability. Permeability differed according to the multilayer overlapping condition. When the relative humidity was high, the "pull-push" effect was insignificant. This is caused by water droplets absorption after the partial migration of water due to condensation. These results suggest that the overlapping conditions and properties of fabrics should vary depending on heavy sweating or not.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.303.1-303.1
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• 2016

Polymer-like amorphous carbon films were deposited on polyethylene naphthalate (PEN) substrate by plasma-enhanced chemical vapor deposition (PECVD) and their water vapor transmission rates (WVTR) were tested. propane was used as precursors. To make a polymer-like amorphous carbon film the deposition rate, surface roughness, light transmittance, and WVTR of the films were characterized as a function of the precursor feed ratio and plasma power. The water vapor transmission rates of bare PEN film and single layer PAC on PEN substrate were 6.95 g/m2/day and 0.3 g/m2/day, respectively. The superior property the water vapor permeability of thin layers of PAC was attributed to uniform coverage and good adhesion between PAC film and PEN substrate.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1224-1229
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• 2004

PHB/chitosan 필름의 수분 투과도는 PHB 필름께서 280.25 g/m$^2$ㆍ24 hr로 가장 높았고 chitosan의 함량이 증파할수록 수분 투과도는 낮아지는 경향을 보였다. PEG가 첨가된 PHB/chitosan 필름에서도 PHB-P 필름의 수분 투과도가 294.5 g/m$^2$ㆍ24 hr로 가장 높았고, chitosan의 함량이 증가할수록 수분 투과도는 낮아졌다. 산소 투과도의 경우 PHB 필름이 0.026${\times}$$10^{-10}$$cm^3$(STP) cm/$cm^2$ㆍsecㆍcmHg로 가장 높았으며 chitosan의 첨가 비율이 증가할수록 산소 투과도는 낮아졌다. 또한 가소제인 PEG가 첨가되지 않은 필름이 PEG가 첨가된 필름보다 산소 투과도가 더 낮았다. 유지 투과도에서는 PHB와 PHB-P를 제외한 필름들이 24시간동안 유지론 통과시키지 않아 유지 차단성이 우수한 것으로 나타났다. 필름의 생분해도 측정시 필름을 첨가하지 않은 대조군에 비해 필름이 첨가된 실험군의 산소 소모량이 높아 필름이 생분해되고 있음을 확인할 수 있었으며 필름의 PHB의 비율이 높을수록 분해도가 높은 것으로 나타났다.

• 한국인터넷방송통신학회논문지
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• 제12권5호
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• pp.255-260
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• 2012

현재 운영되는 주요 하 폐수 처리시설 관리에 있어 환경 보호를 위한 엄격한 규제로 수질오염 측정 시스템에 관한 시스템이 부각되고 있다. 하지만 기존 하 폐수 처리 시스템은 하 폐수에 특화된 수질감시 기술이 미흡하며, 그중 센서와 네트워크를 통한 1:n 데이터 전송이 아닌 1:1을 지향하며, 이기종간 통신방식에 대한 호환성이 미비하다. 또한, 주로 수동방식의 검출방식을 준수하고 있다. 이에 본 논문에서는 수질복원시설물 내에 자동화된 센서 네트워크 통합 인터페이스를 위한 센서와 수질감지통합인터페이스간의 효율적인 데이터 전송에 관한 프로토콜 기술에 관해 연구하였다. 센서 네트워크 통합 인터페이스용 모니터링 구현을 통해 이기종간 통신방식으로 원활한 데이터 전송이 가능함을 입증하였다.

• 한국세라믹학회지
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• 제56권6호
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• pp.601-605
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• 2019

This work reports the preparation of ceramic hybrid films with illite-polyethylene composites analyzed as a function of concentration of added illite in polyethylene. The enhancement of oxygen and water-vapor transmission rate of illite-polyethylene film was evaluated to determine its influence on the freshness in fruit packaging. Particle size of illite materials was controlled in the range of 1~10 ㎛ and then mixed with LDPE to form the masterbatch. Ceramic hybrid films were prepared through a blown film making process. To determine the dispersity and abundancy of illite materials in the polyethylene matrix, various characterizations of illite-PE hybrid masterbatch and films were performed using SEM, TGA, and FT-IR. The oxygen and water-vapor transmission rate of illite-polyethylene film was found to be two times higher than that of LDPE film.