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        검색결과 18

        1.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng μL-1] and 88.4 [ng μL-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng μL-1] and 74.8 [ng μL-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.
        4,000원
        2.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 ICT 산업의 기술혁신이 일어남에 따라 생체신호을 인식하고 이에 대해 대응을 하기 위한 웨어러블 센싱 장치에 대한 수요가 증가하고 있다. 이에 따라 본 연구에서는 단순한 함침과정을 통해 3차원 스페이서(3D spacer)직물 을 단일벽 탄소나노튜브(SWCNT)분산용액에 함침공정을 진행해 단일층(monolayer) 압전 저항형 압력 센서 (piezoresistive pressure sensor)를 개발하였다. 3D 스페이서 원단에 전기전도성을 부여하기 위해 시료를 SWCNT 분 산용액에 함침공정을 진행한 후 건조하는 과정을 거쳤다. 함침된 시료의 전기적 특성을 파악하기 위해 UTM (Universal Testing Machine)과 멀티미터를 이용해서 압력의 변화에 따른 저항의 변화를 측정하였다. 또한 센서의 전기적 특성의 변화를 관찰하기 위해 분산용액의 농도, 함침횟수, 시료의 두께를 다르게 해서 시료의 센서로서의 성능을 평가했다. 그 결과 wt0.1%의 SWCNT 분산용액에 함침공정을 2번 진행한 시료가 센서로서 가장 뛰어난 성능 을 나타냄을 알 수 있었다. 두께별로는 7mm 두께의 센서가 가장 높은 GF를 보이고 13mm 두께의 센서가 작동범위가 가장 넓음을 확인했다. 본 연구를 통해 3D spacer 원단으로 제작한 스마트 텍스타일 센서는 공정과정이 단순하면서도 센서로서 성능이 뛰어나다는 장점을 확인할 수 있었다.
        4,000원
        4.
        2018.04 구독 인증기관·개인회원 무료
        벗초파리는 우리나라에서는 심각한 해충으로 인식되지 않아 발생 기간 및 패턴, 기주 범위 등의 생태적인 연구뿐만 아니라 모니터링을 위한 우수 유인제 및 트랩의 연구도 제한적으로 수행된 실정이다. 본 연구는 기존 연구 결과를 참조하여 사과식초 함유 유인제 2종과 화학적 루어 2종 그리고 트랩 2종에 대한 선발 시험을 수행하였다. 선발 시험은 사육중인 벗초파리를 이용한 choice test와 함께 수목원, 딸기 농장, 블루베리 농장에서의 6반복 유인력 검증 실험을 수행하였다. 유인력 비교 결과 ACV + wine의 포획량이 높았으며, 블루베리 농장 인근 결과값은 전체 조사 항목에서 통계적 유의성을 보였다 (P < 0.05). 트랩 선발 실험 결과 모든 실험 장소에서 Dreves 트랩이 높은 포획량을 보였다. 이상의 결과를 통해 ACV + wine과 Dreves 트랩 조합을 선발하였으며, 이를 이용하여 향후 지속적인 모니터링, 월동 발생 조사 등의 연구에 활용할 수 있을 것으로 생각된다.
        5.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 초고층건축물의 풍진동 모니터링을 위한 시스템식별기법의 현장적용성을 평가하였다. 실제 아웃리거-벨트월 을 횡력저항 시스템으로 가지는 실제 63층 RC구조물을 대상으로 상시 및 강풍시 응답을 모니터링하였으며, 진동수영역분해(FDD), 랜덤감소(RDT)기법, 부분공간시스템식별(SSI)법을 사용하여 진동특성을 식별하였다. 건물의 평면이 정방형이고, 두 개의 횡방향 모드의 진동수는 매우 유사하였다. 모든 식별기법에서 태풍과 같이 강한 외력이 존재할 경우 뿐만 아니라 상시미진동 에서도 구조물의 모드 특성을 식별할 수 있었다. 현장에서의 적용성 평가결과, 계산속도는 FDD가 가장 빨랐으며, RDT가 가장 간단한 프로그래밍 절차를 가지고 있음을 확인하였다.
        4,000원
        6.
        2015.10 구독 인증기관·개인회원 무료
        The small brown planthopper (SBPH), Laodelphax striatellus Fallen, is an important pest that causes severe yield losses by transmitting plant viruses to rice. For the efficient control of SBPH in Korea, the respective resistance levels in the immigrant and indigenous populations need to be discerned. The resistance levels to 10 insecticides (three carbamates, an organophosphate, four neonicotinoids, and a phenylpyrazole) were evaluated in 21 field populations collected from either SBPH-immigrating or indigenous regions during two different seasons (early spring vs. late summer). Imidacloprid resistance was most widely observed in many regional populations, followed by thiamethoxam resistance. Interestingly, the resistance level to imidacloprid was significantly higher in both immigrant and late-summer-collected populations than in indigenous and early spring-collected populations, respectively [3.3- (p = 0.018) and 2.6-fold (p = 0.026)]. Moreover, the late summer immigrant population exhibited higher imidacloprid resistance (2.4-fold) than the early spring-collected population from the same region, suggesting that the migratory SBPH that immigrated into Korea already exhibited imidacloprid resistance traits and were further selected after inhabitation. All field populations showed little resistance to fipronil (0.1- to 0.7-fold), suggesting that it is the most effective among the tested insecticides to control field populations of SBPH. The coefficient of variation of the resistance ratio (RR) among different regional populations and the correlation coefficient of RR among different insecticides have been suggested as supplementary parameters when determining appropriate insecticides as respective indicators for the dispersion status of resistance among SBPH populations and the possibility of cross resistance among tested insecticides.
        7.
        2015.04 구독 인증기관 무료, 개인회원 유료
        The deep see riser is often exposed to harsh ocean environment which may cause riser failure. If the riser fails, it may cause serious economical losses as well as environmental problems. Thus, monitoring the integrity of the rider for preventing sudden failure is very important. In this study, the structural behavior monitoring systems installed for the deep sea riser are examined, and, using the estimated behavior, the applicability of the structural integrity evaluation methods is examined via numerical analysis.
        3,000원
        8.
        2012.09 구독 인증기관 무료, 개인회원 유료
        Environmental problems such as global warming become social issues today. It is reported that increasing energy consumption has affected on these environmental issues. Buildings deploys 40 percent of the raw materials in the world while at the same time they emit over 35 percent of the total CO2, so that it utilize over 50 percent of the whole energy in the world. At this point, energy saving though effective building control may eventually bring social, environmental and economical effects. Thus, this study will explore the difference between measured temperature and monitored temperature for operating air control system in the building, to which BEMS is applied. Also, it will suggest a method to accurately predict the load of air-conditioning, and will examine the different amounts of the load according to the temperature as well as the reduced amount of the load through changes of operation standard temperature.
        4,000원
        9.
        2010.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study developed the pressure measurement monitoring system named VIP-2000 for monitoring a pressure of ullage space in cargo tank. VIP-2000 is designed in compliance with IMO(international maritime organization) SOLAS 74, Chap. II-2 Req. 59. IMO is providing the establishment of a pressure measurement equipment for secure the stability from vacuum or the overpressure that caused by in breakdown of the P/V valve. VIP-2000 operates the early warning of the visible and audibility in dangerous situation of cargo tank. In order to evaluate the performance of VIP-2000, the pressure measurement experiments have been conducted.
        4,000원
        10.
        2004.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        방사성핵종의 특성, 섭취형태 그리고 내부피폭 감시주기는 작업자의 방사성핵종 섭취량 및 내부피폭선량 평가 결과에 중요한 영향을 줄 수 있다. 따라서 방사성핵종이 흡입섭취 될 경우 섭취형태(급성 또는 만성) 및 내부피폭 감시주기에 따른 섭취량 평가 오차를 계산하였다. 섭취 핵종으로는 /I(Type F), Cs(Type F), U(Type M, Type S)를 고려하였고, 방사능입자크기(AMAD)는 1 와 5 를 고려하였다. 섭취형태에 따라 평가된 섭취량의 상대오차는 방사성핵종, 흡수형태 그리고 내부피폭 감시주기에 따라 달랐으나, 입자크기에 의한 영향은 거의 없었다. 섭취형태 가정에 따른 섭취량 평가 오차를 10% 미만으로 줄일 수 있는 내부피폭 최대감시주기는 /I(Type F)에 대해 60일, Cs(Type F)에 대해 180일, U(Type M)에 대해 90일, 그리고 U(Type S)에 대해 360일로 나타났다.
        4,000원
        11.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the necessity of developing effective nondestructive testing and monitoring techniques for the evaluation of structural integrity and performance is described. The evaluation of structural integrity and performance is especially important when the structures and subject to abrupt external forces such as earthquake. A prompt and extensive inspection is required over a large area of earthquake-damaged zone. This evaluation process is regarded as a part of performance-based design. In the paper, nondestructive testing and monitoring techniques particularly for concrete structures are presented as methods for the evaluation of structural integrity and performance. The concept of performance-based design is first defined in the paper followed by the role of evaluation of structures in the context of overall performance=based design concept. Among possible techniques for the evaluation, nondestructive testing methods for concrete structures using radar and a concept of using fiber sensor for continuous monitoring of structures are presented.
        4,000원
        12.
        2019.10 서비스 종료(열람 제한)
        공용 중인 교량의 건전성을 파악하고 유지관리에 활용하기 위해 서해대교 사장교 구간에는 구조건전성모니터링(structural health monitoring) 시스템이 설치되어 있다. 이를 통해 바람, 지진과 같은 작용하중(applied loads)과 함께 진동, 형상변화, 신축, 부재력, 응력(변형률)과 같은 구조응답(structural response)을 모니터링하고 있다. 2000년 준공 이후 현재까지 장기간 축적된 구조응답 데이터를 기반으로 분석 및 평가를 수행한 결과, 상시 거동뿐만 아니라 다양한 재난상황 시에도 교량 구조계의 거동은 건전한 상태임을 확인할 수 있었다.
        13.
        2019.04 서비스 종료(열람 제한)
        This paper discusses the loads on bridges based on long-term measurements. Applied Loads such as winds, earthquakes, temperature variations and traffic effects have been monitored on an existing bridge from the completion of the structure to now. It is confirmed that the monitoring results are within the design values.
        14.
        2019.04 서비스 종료(열람 제한)
        In this study, prototype DAU with LoRa wireless communication module is designed and manufactured. Also, the customized software is developed for the automatic data transmission to end-user from ThingPlug server of SK telecom LoRa network. For verification of the developed wireless monitoring system, DAU was installed on bridge construction site. The reliability of data and operational stability was evaluated by comparison with data from conventional monitoring system.
        15.
        2014.04 KCI 등재 서비스 종료(열람 제한)
        Effects of coagulation types on flocculation were investigated by using a photometric dispersion analyzer (PDA) as an on-line monitoring technique in this study. Nakdong River water were used and alum and ferric chloride were used as coagulants. The aim of this study is to compare the coagulation characteristics of alum and ferric chloride by a photometric dispersion analyzer (PDA). Floc growing rates (Rv) in three different water temperatures (4℃, 16℃ and 30℃) and coagulants doses (0.15 mM, 0.20 mM and 0.25 mM as Al, Fe) were measured. The floc growing rate (Rv) by alum was 1.8∼2.8 times higher than that of ferric chloride during rapid mixing period, however, for 0.15 mM∼0.25 mM coagulant doses the floc growing rate (Rv) by ferric chloride was 1.1∼2.3 times higher than that of alum in the slow mixing period at 16℃ water temperature. Reasonable coagulant doses of alum and ferric chloride for turbidity removal were 0.1 mM (as Al) and 0.2 mM (as Fe), respectively, and the removal efficiency of those coagulant doses showed 94% for alum and 97% for ferric chloride. The appropriate coagulant dose of alum and ferric chloride for removing dissolved organic carbon (DOC) showed about 0.3 mM (as Al, Fe) and at this dosage, DOC removal efficiencies were 36% and 44%, and ferric chloride was superior to the alum for removal of the DOC in water.
        16.
        2014.02 서비스 종료(열람 제한)
        기후변화 등으로 인해 우리나라를 비롯한 전 세계적으로 물관련 재해 빈도는 지속적으로 증가하고 있으며, 경제발전에 따라 관련 피해 규모도 기하급수적으로 커지고 있는 실정이다. 따라서, 물관련 재해에 대한 국가적 대응 체계 구축 뿐만 아니라 재해예측 정확도를 향상시키기 위한 다양한 노력이 필요하다. 아울러, 정부 3.0 시대를 맞이하여 국가가 수재해 관련 정보를 국민들이 실시간으로 쉽고 간편하게 이용할 수 있도록 하는 정보제공 체계 구축이 필요한 시점이다. 이를 위해서는 국토교통부 및 기상청 등 다양한 정부부처에서 획득되는 자료 뿐만 아니라 미국 등 선진국에서 제공하고 있는 다양한 위성영상을 통합하고 종합적으로 분석할 수 있는 국가적 시스템 구축이 요구된다. 이를 통해 동남아 및 아프리카 등 저개발 국가의 물관련 재해 예측 및 전지구적 차원의 기후변화 대응 노력에 동참함으로써 선진국으로서의 책임과 위상 강화는 물론 글로벌 물산업 진출을 위해 필요한 핵심 정보들을 전략적으로 획득할 수 있는 체계가 마련될 수 있다. 이에 본 연구에서는 국내외에서 현재 운용 중에 있는 위성영상, 레이더 강우, 자동기상관측소 등에서 획득되는 다양한 물관련 정보들을 융합해 국지 혹은 광역적인 지역에 대한 가뭄이나 하천건천화, 홍수 등과 같은 수재해를 과학적이고 효율적으로 감시, 평가 및 예측하기 위해 필요한 기술들을 제시하고자 한다.
        17.
        2011.12 KCI 등재 서비스 종료(열람 제한)
        Emission reduction program for in-use diesel vehicles(ERPDV) has been enacted since 2004 over the Seoul metropolitan area, and diesel emission reduction is forced to fulfill this regulation. This study was performed to evaluate the ERPDV using PM10 concentrations of both road-side monitoring and national background network during the period of 2004-2010. In order to assess the pure road emission, we first eliminated the long range transport effect by deducting the trend of annual national background concentrations from the road-side PM10 concentrations, and then analyzed the time series of the resultant PM10 concentrations over Seoul metropolitan area. The annual rates of variations of road-side PM10 with the deduction of trend of background level show -3.2, +0.4, and -2.4㎍/㎥/year, in Seoul, Incheon, and Gyonggi province, respectively. There are steadily decreasing trend in Seoul with all of statistic parameters such as mean, mediam, 5%ile, 10%ile, 25%ile, 75%ile, 90%ile, and 95%ile concentrations. Incheon shows some fluctuations with positive with no significant trend, and Gyonggi province shows overall decreasing but not consistent. Student-t test shows 95% significant level of ERPDV effect in Seoul, but there exists no significant level greater than 90% in both Incheon, and Kyonggi province. Total annual averaged trend over the whole Seoul metropolitan area is estimated to lie in approximately -2.9㎍/㎥/year in this study, implying the intimate involvement of ERPDV to a large extent. This is also suggesting that the further research cost-effectiveness of ERPDV with consideration of the long range transport process would be needed over the Seoul metropolitan area.