• 제목/요약/키워드: Time of wetness

검색결과 72건 처리시간 0.026초

Weight of Evidence 기법을 이용한 영남지역의 산지습지 가능지역 추출 (Potential Mapping of Mountainous Wetlands using Weights of Evidence Model in Yeongnam Area, Korea)

  • 백승균;장동호
    • 한국지형학회지
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    • 제20권1호
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    • pp.21-33
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    • 2013
  • 이 연구에서는 접근이 어렵고 범위가 광대하여 많은 시간과 비용이 소요되는 산지습지의 현장조사 대상범위를 줄이고 작업의 효율성을 높이기 위해 산지 습지 위치와 지형 및 기타 GIS 정보 사이의 관계를 확률로 표현하는 Weight of Evidence 기법을 적용하여 산지습지 가능지역을 추출하였다. 이를 위하여 영남지역을 대상으로 산지습지와 관련된 경사 분포, 곡률 분포, 식생지수 분포, 습윤지수 분포, 토양 배수등급 분포 등 공간 데이터베이스를 구축하고 이를 기존 산지습지 위치와의 상관관계를 통하여 Weight of Evidence를 구하였다. 우도비를 통하여 산지습지 가능성에 대한 각 요인의 등급을 분석한 결과 경사도, 곡률, 식생지수, 습윤지수가 낮을수록, 토양 배수등급이 양호한 곳에 산지습지 분포 가능성이 높은 것으로 나타났다. 산지습지가능성도 작성을 위하여 각 요인의 등급에 대하여 Weight of Evidence 가중치를 부여하고 GIS 중첩분석을 실시하여 산지습지가능지수를 산출하였다. 그리고 검증을 위하여 산지습지 가능지수 등급구간에 대한 산지습지 위치 포함 누적비율을 표시한 성공확률곡선을 작성하고 면적비율을 계산한 결과 75.48%로서 상당히 높은 예측정확도를 나타내었다.

Corrosion Behavior of Zn and Zn-AI Alloy Coated Steels under Cyclic Wet-dry Environments

  • Nishikata, Atsushi;Yadav, Amar Prasad;Tsutsumi, Yusuke;Tsuru, Tooru
    • Corrosion Science and Technology
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    • 제2권4호
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    • pp.165-170
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    • 2003
  • Atmospheric corrosion behaviors of Zn, Zn-5%Al and Zn-55%A l coated steels have been investigated under cyclic wet-dry environments containing chloride ions. The wet-dry cycle was carried out by alternate exposure to immersion in 0.5 M (or 0.05 M) NaCl solutions and drying at $25^{\circ}C$ and 60 %RH. The polarization resistance $R_p$ and solution resistance $R_s$ were monitored by AC impedance technique. From the obtained $1/R_p$ and $1/R_s$ values, the corrosion rate of the coatings and the Time of Wetness (TOW) were estimated, respectively. Effects of chloride ions and TOW on the corrosion rates of Zn, Zn-5%Al, Zn-55%Al coatings and appearance of red rust (onset of underlying steel corrosion) under wet-dry cycles are discussed on the basis of the corrosion monitoring data.

항공기 주기환경이 대기부식위험도에 미치는 영향 (The Effect of Aircraft Parking Environment on Atmospheric Corrosion Severity)

  • 윤주희;이두열;박승렬;김민생;최동수
    • Corrosion Science and Technology
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    • 제20권2호
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    • pp.94-104
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    • 2021
  • Atmospheric corrosion severity associated with aircraft parking environment was studied using metallic specimens, and temperature and humidity sensors installed at each aircraft operating base. Data were analyzed after a year of exposure. Silver was used to measure chloride deposition by integrating X-ray photoelectron spectroscopy depth profiles. Carbon steel was utilized to determine the corrosion rate by measuring the weight loss. The time of wetness was determined using temperature and humidity sensor data. Analysis of variance followed by Tukey's "honestly significant difference" test indicated that atmospheric environment inside the shelter varied significantly from that of unsheltered parking environment. The corrosion rate of unsheltered area also varies with the roof. Hierarchical clustering analysis of the measured data was used to classify air bases into groups with similar atmospheric corrosion. Bases where aircraft park at a shelter can be grouped together regardless of geographical location. Unsheltered bases located inland can also be grouped together with sheltered bases as long as the aircraft are parked under the roof. Environmental severity index was estimated using collected data and validated using the measured corrosion rate.

UV조사 처리한 PET의 역학적 특성변화와 감성평가 (The physiological properties and sensibility of PET irradiated by ultraviolet rays)

  • 최혜영;이정순
    • 한국생활과학회지
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    • 제15권2호
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    • pp.275-281
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    • 2006
  • The purpose of this study is to investigate hand and sensibility of PET treated by Ultra-Violet (UV). The 4-channel PET knit fabric was treated by a self-made UV instrument in 5cm distance with different time frames-0min, 30min, and 90min. For hand evaluation, mechanical properties were measured by the KES-FB system. The environmental condition was controlled at 29$^{\circ}C$, 75% (R.H.)-summer standard climate. Twenty female students evaluated 'roughness', 'smoothness', 'wetness', 'stiffness', 'coolness', 'touch', 'preference', and 'comfort'. The outcomes of the experiment are as follows: The surface roughness of mechanical properties showed significant differences and the value of PET irradiated by UV for 90min was highest. The order of primary hand value such as NUMERI and FUKURAMI was in a following order-Untreated > 30min treated > 90min treated. Total hand value showed that PET irradiated by UV for 90min was appropriate for using summer fabric. The results of subjective sensibility were that the untreated and 30min treated PET were recognized as similar and had a good evaluation on 'comfort', 'preference' and 'the sense of touch'. This consequence disagreed with total hand value, because it was considered that subjects' hand sensibility was dependent on the feel of smoothness.

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The Influence of Surface Modification of Gold Nanoparticles Supported on TiO2 in the Catalytic Activity of CO Oxidation

  • Park, Da-Hee;Reddy, A.S.;Eah, Sang-Kee;Park, Jeong-Young
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.213-213
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    • 2011
  • Gold catalysts supported on TiO2 have shown a unique catalytic behavior on CO oxidation, depending on surface effects. Particle size has an influence on the surface activity. To make monodisperse Au nanoparticles, organic capping ligands, such as alkylthiols, were used by a "greener" synthesis method [1,2] and Au nanoparticles were deposited on TiO2. However, organic capping ligands must be removed for high catalytic activities by the Au nanoparticles without changing the Au size [3]. We used UV ozone treatment to decompose thiol ligands. The samples have been characterized by X-ray photoelectron spectroscopy to examine the surface modification by UV ozone treatment. We show the size distribution of the gold nanoparticles by light scattering analysis and transmission electron microscopy. Au/TiO2 have been prepared using the wetness impregnation method. The catalytic performance of CO oxidation over Au supported on TiO2 under oxidizing reaction conditions (40 Torr CO and 100 Torr O2) were tested. The results show that the catalytic activity depends on particle size and the time of UV ozone exposure, which suggests the role of sulfur bonding in determining the catalytic activity of Au/TiO2 catalysts.

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제주도 대기환경의 부식성 평가 (Assessment of Atmospheric Corrosivity at Jeju Island)

  • 김귀식;양경조;허철구;송정화
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.253-259
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    • 2004
  • The Jeju Island in Korea is the clean area which the tradition culture is preserved locally well with the nature environment of Heaven's blessing. An air pollution is becoming recently serious problem as the industrial development is proceeded with the urbanization. This study investigates that the atmosphere environment at Jeju area influences on the metal corrosion. A study of the atmosphere corrosion for carbon steel, copper, zinc ana aluminium exposed on five test sites indoors and outdoors. Corrosion results are treated statistically and adjusted to a model previously proposed for carbon steel, copper, zinc and aluminium based on the influence of environmental parameters and main pollutants($SO_2$ and chlorides) on tire atmosphere corrosion of metals. Through this study, we try to set the standards atmosphere corrosion at Jeju Island.

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다중센서 기반 서리관측 시스템의 개선: MFOS v2 (Improvement of Multiple-sensor based Frost Observation System (MFOS v2))

  • 김수현;이승재;김규랑
    • 한국농림기상학회지
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    • 제25권3호
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    • pp.226-235
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    • 2023
  • 본 연구는 개선된 '다중센서 기반 무인 서리관측시스템(MFOS, Multiple-sensor based Frost Observation System)'을 소개하였다. 개선된 시스템인 MFOS v2는 엽면습윤센서를 기반으로 서리 감지는 물론, 서리 발생 주요 인자인 표면온도 예측을 위한 기능도 겸한다. 기존 관측 시스템은 1) 엽면습윤센서 표면이 대부분의 가시광선을 반사하기 때문에 RGB 카메라로 엽면습윤센서 촬영 시 표면에 발생한 얼음(서리) 관측이 어려움, 2) 일출 전과 후에 RGB 카메라 촬영 결과가 어두움, 3) 열적외선 카메라가 온도의 상대적인 고저만을 보여주는 단점들이 존재하였다. 엽면습윤센서 표면에 발생한 얼음(서리) 파악을 위해 검정색으로 표면 도색된 엽면습윤센서를 추가 설치하였고, 동일한 높이에 유리판들을 설치하여 얼음(서리) 발생 확인을 위한 보조 도구로 활용하였다. 일출 전과 후에 RGB 카메라 촬영을 위해 카메라 촬영 시간에 맞춰 전원이 On/Off 되도록 LED 조명을 연동시켜 설치하였다. 상대적인 온도의 높고 낮음 판단만 가능했던 기존의 열적외선 카메라도 픽셀당 온도 값 추출이 가능하도록 개선하였다. 이러한 개선 사항들을 반영한 MFOS v2는 실제 농경지에 설치하여 운영 중이며, 서리예측 모델에 들어갈 입력자료를 생산하는 진보된 서리 관측시스템으로서 중요한 역할을 할 것으로 기대된다.

인공신경망을 이용한 풍화토의 강도정수 산정 (Assessment of Shear Strength Parameter for Weathered Soils Using Artificial Neural Network)

  • 이무철;이송
    • 한국구조물진단유지관리공학회 논문집
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    • 제12권3호
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    • pp.147-154
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    • 2008
  • 풍화토 사면은 장시간 공기에 노출되거나 물과 접촉을 하게 되면 전단강도가 급격히 저하되며 계절에 따른 수위의 변화가 매우 큰 댐사면의 경우는 강도저하가 더욱 크게 발생한다. 풍화토 사면의 강도저하 파악을 위하여 반복전단시험 및 수침 건조를 반복한 시료에 대한 잔류강도 시험을 통해 포화에 따른 강도의 저하를 파악하였다. 또한 소형동적콘관입시험기를 이용하여 관입타격횟수와 전단강도정수관계를 파악하고 인공신경망 해석을 통하여 관입타격횟수 Nc를 이용한 전단강도정수의 예측이 용이하도록 상관식을 구성하였다.

강원고랭지 농업기상 감시 및 분석시스템 구축 (System Networking for the Monitoring and Analysis of Local Climatic Information in Alpine Area)

  • 안재훈;윤진일;김기영
    • 한국농림기상학회지
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    • 제3권3호
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    • pp.156-162
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    • 2001
  • In order to monitor local climatic information, twelve automated weather stations (AWS) were installed in alpine area by the Alpine Agricultural Experiment Station, Rural Development Administration (RDA), at the field of major crop located in around highland area, and collected data from 1993 to 2000. Hourly measurements of air and soil temperature (underground 10 cm,20 cm), relative humidity, wind speed and direction, precipitation, solar radiation and leaf wetness were automatically performed and the data could be collected through a public phone line. Datalogger was selected as CR10X (Campbell scientific, LTD, USA) out of consideration for sensers' compatibility, economics, endurance and conveniences. All AWS in alpine area were combined for net work and daily climatic data were analyzed in text and graphic file by program (Chumsungdae, LTD) on 1 km $\times$ 1 km grid tell basis. In this analysis system, important multi-functionalities, monitoring and analysis of local climatic information in alpine area was emphasized. The first objective was to obtain the output of a real time data from AWS. Secondly, daily climatic normals for each grid tell were calculated from geo-statistical relationships based on the climatic records of existing weather stations as well as their topographical informations. On 1 km $\times$ 1 km grid cell basis, real time climatic data from the automated weather stations and daily climatic normals were analyzed and graphed. In the future, if several simulation models were developed and connected with this system it would be possible to precisely forecast crop growth and yield or plant disease and pest by using climatic information in alpine area.

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관수주기에 따른 실내녹화용 목본식물 4종의 초기 생육반응 (Initial Growth Responses of Four Woody Plants for Indoor Landscaping according to Irrigation Frequency)

  • 권계정;박봉주
    • 한국조경학회지
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    • 제45권1호
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    • pp.28-34
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    • 2017
  • 본 연구는 실내에 많이 사용되는 목본식물인 산호수(Ardisia pusilla), 클루시아(Clusia rosea), 팔손이(Fatsia japonica), 인도고무나무(Ficus elastica)를 대상으로 관수주기에 따른 식물생육 상태를 측정하여 향후 실내 환경개선에 도움이 되는 조경식물의 적절한 관수주기를 구명하고자 수행하였다. 목본식물 4종을 10cm 포트에 식재하여, 관수주기를 2회/1주, 1회/1주, 1회/2주의 3수준으로 하여 120일 동안 처리한 후, 초고, 생체중, 건조중, SPAD, 엽색, 엽수분포텐셜, 엽록소 형광(Fv/Fm), 광합성율을 측정하였다. 실험기간 동안 평균 토양수분함량은 2회/1주 $48.8{\pm}2.1%$, 1회/1주 $25.2{\pm}4.4%$, 1회/2주 $10.3{\pm}2.4%$ 순으로 나타났다. 2회/1주 관수 시 산호수는 엽수분포텐셜이 높게 나타났고, Fv/Fm이 0.731로 나타나 과습에 대한 스트레스를 보였다. 1회/2주 관수 시 산호수, 팔손이, 인도고무나무의 광합성율은 유의성이 없어 클루시아에 비해 건조에 민감한 것으로 나타났다. 1회/1주 관수하여 평균 토양수분함량이 25%일 때 본 실험에 사용된 4종 목본식물 모두 실내 생육이 원활한 것으로 나타나 실내조경용으로 이용성이 높을 것으로 판단된다.