• 제목/요약/키워드: HGM

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HGM을 이용한 질날늪 기능평가 연구 (Functional Assessment of Jilnalnup Wetland by HGM)

  • 김예화;이란;문상균;구본학
    • 한국환경복원기술학회지
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    • 제16권2호
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    • pp.13-22
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    • 2013
  • Wetlands occupy an important ecological position on the earth, carrying out very important functions and roles both ecologically and hydrologically. However, due to past industrialization, not only wetland areas but also the biodiversity of organisms has severely decreased due to several artificial interferences and damage as wetlands began to be perceived simply as targets for development and reclamation. However in recent times, with the importance of wetlands coming to the fore, the assessment of the function and value of wetlands is being made for their wise use and systematic maintenance. Accordingly, this study targeted the Jilnal Wetlands located in Haman, Gyeongnam, and conducted a functional appraisal of this wetland using the modified HGM Model which was modified & developed appropriately for the actual conditions of our country. The result of its appraisal by selecting the Upo Wetland as the reference wetland, which is a criterion of the index, showed a comparatively positive functional index with 0.89 of the Upo Wetland average. This means that the Jilnal Wetland carrys out more than 89% of the functioning of the Upo Wetland. In this regard, it is thought that the Jilnal Wetland could carry out the wetland functioning equivalent to that of the Upo Wetland through a little more systematic management.

고구마 조기재배시 품종별 생육과 괴근비대 특성 (Growth Characteristics of Sweet Potato (Ipomoea batatas) Cultivars according to Growth Period in Early Cultivation)

  • 황엄지;남상식;이준설;이형운;양정욱
    • 한국작물학회지
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    • 제62권1호
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    • pp.51-59
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    • 2017
  • 본 연구에서는 소비자의 선호 품종의 변화 및 고구마 조기생산을 위한 삽식 및 수확시기 변화에 대응하기 위하여 주요 품종의 삽식 시기에 따른 생육기간별 고구마 생육 특성을 구명하였다. 분질고구마(율미, 진홍미)의 괴근 형성은 삽식 후 50일에 괴근 무게는 각각 4.1, 8.6 g이었으며, 두 품종에서 80일 이후 급격하게 무게가 증가하였고 120일에 괴근 평균 무게는 율미 120.7 g, 진홍미 79.4 g 으로 나타났다. 중간질고구마(풍원미, 호감미)는 삽식 50일 후 괴근 무게가 각각 13.0, 3.3 g이었으며 삽식 후 120일에 괴근 무게는 풍원미 104.2 g, 호감미 68.1 g이었다. 자색고구마(신자미, 단자미)의 괴근형성은 삽식 후 50일에 시작되었으며, 120일에 괴근 무게는 신자미 132.7 g, 단자미 68.0 g이었다. 조기재배 시 율미와 풍원미, 신자미는 삽식 후 120일 전후로 수확이 가능한 조기비대성 품종, 진홍미는 삽식 후 130일, 호감미 단자미는 삽식 후 130일 이상 되어야 수확가능한 만기비대성 품종으로 판단된다.

습지 기능 평가의 동향 분석 및 제언 (An analysis of trends in wetland function assessments and further suggestions)

  • 홍문기;김재근
    • 한국습지학회지
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    • 제19권1호
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    • pp.1-15
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    • 2017
  • 습지를 대상으로 한 기능 평가는 습지의 현 상태를 면밀히 파악하기 위한 기본 단계일 뿐만 아니라 습지를 '우리에게 수많은 편익을 제공하는 하나의 자원이자 재화'로 인식하는 '생태계 서비스' 개념의 토대가 되는 중요한 과정이다. 20세기말 미국에서부터 시작된 습지 기능 평가는 WET, EMAP-wetlands 그리고 HGM의 순서로 발달하였다. 21세기에 접어들며 보다 간편하고 신속하게 수행 가능한 RAM이 기능 평가 개발의 주류를 이루기 시작하였다. 그 이후에는 세 가지 수준의 위계를 갖는 기능 평가의 체계가 갖추어졌으며 기능 평가의 대상과 목적 등에 따라 전략적으로 활용되는 형태로 발전하였다. 우리나라 또한 미국의 HGM과 RAM을 토대로 하여 일부 항목과 내용들을 개선하는 형태로 한 기능 평가가 2001년부터 수행되기 시작하였다. 이후 HGM과 RAM의 약점과 단점을 보완할 뿐만 아니라 우리나라의 환경 특성 및 실정에 맞게 개선된 형태의 기능 평가 도구들이 개발되기 시작하였다. 국내외 습지 기능 평가 연구 동향파악 및 선진국과의 비교 분석을 통해 국내 기능 평가에 있어 우선적으로 보완이 필요한 것들로 다음의 사항들을 제안하는 바이다: 1) 조류와 같이 우리나라의 현실을 고려한 지시자를 활용한 기능 평가 도구가 필요하다. 2) 우리나라 습지의 많은 면적을 차지하고 있는 연안습지를 대상으로 하는 최적화된 기능 평가 도구 개발이 필요하다. 3) 연구자 및 정책담당자들 간의 소통과 협력 공조를 유도할 수 있는 네트워크 구축과 확장이 필요하다.

The influence of vertical ground motion on the seismic behavior of RC frame with construction joints

  • Yu, Jing;Liu, Xiaojun
    • Earthquakes and Structures
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    • 제11권3호
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    • pp.407-420
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    • 2016
  • The aim of this study is to investigate the effect of vertical ground motion (VGM) on seismic behavior of reinforced concrete (RC) regular frame with construction joints, and determine more proper modeling method for cast-in-situ RC frame. The four-story RC frames in the regions of 7, 8 and 9 earthquake intensity were analyzed with nonlinear dynamic time-history method. Two different methods of ground motion input, horizontal ground motion (HGM) input only, VGM and HGM input simultaneously were performed. Seismic responses in terms of the maximum vertex displacement, the maximum inter-story drift distribution and the plastic hinge distribution were analyzed. The results show that VGM might increase or decrease the horizontal maximum vertex displacement depending on the value of axial load ratio of column. And it will increase the maximum inter-story drift and change its distribution. Finally, proper modeling method is proposed according to the distribution of plastic hinges, which is in well agreement with the actual earthquake damage.

HTS high gradient magnetic separator prototype

  • Diev, D.N.;Lepehin, V.M.;Makarenko, M.N.;Polyakov, A.V.;Shcherbakov, V.I.;Shutova, D.I.;Surin, M.I.;Tagunov, E. Ya.
    • 한국초전도ㆍ저온공학회논문지
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    • 제20권4호
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    • pp.1-5
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    • 2018
  • A high gradient magnetic (HGM) separator prototype with the $2^{nd}$ generation high temperature superconducting (2G HTS) magnetic system operated in sub-cooled nitrogen is presently under development at NRC "Kurchatov Institute" (Moscow, Russia). The main goal of the project is an attempt to shift away from the complicated liquid helium cryostats towards simple cryocooler-based nitrogen cryogenics as much more convenient for HGM separators industrial applications. Using of commercial HTS tapes allows to get a sufficient level of magnetic fields and extraction forces with low energy consumption. The expected operational parameters of the device are 1.2-1.5 T in the empty operational gap and up to 3 T on the ferromagnetic filters. In this paper we briefly describe the design of the HTS rotary separator prototype with the horizontally oriented rotor axis and propose different types of ferromagnetic filters intended for weakly magnetic ores enrichment.

연안역의 환경과 미티게이션 기술 (Water Environment and Mitigation Technique of Coastal Zone)

  • 최영박
    • 기술사
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    • 제33권1호
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    • pp.51-60
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    • 2000
  • The mitigation technique is to minimize influences to the environments, and it is one of the environmental management(or administration) to techniques. Its objective is to create sustainable environment by keeping human assistance to the environment as minimal as possible. It restores, creates, enhances, and most importantly preserves the environment by avoiding, minizing, rectifying, eliminating, and compensating the natural circumstances The evaluation of adverse effects to the environment and their reduction is as follow: HEP(Habitat Evaluation Procedure) WET(Wet land evaluation technique) HGM(Hydro Geomorphic Assessment) BEST(Biological Evaluation Standardized Technique) Since there are both pro and cons in the American and Japanese mitigation methods, it is hard to choose which one is better.

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중공 미소 유리구를 이용한 LED 스크린 모아레 억제 (Suppression of Moiré Fringes Using Hollow Glass Microspheres for LED Screen)

  • 홍송은;나정필;정모세;김기은;박종운
    • 반도체디스플레이기술학회지
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    • 제22권3호
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    • pp.28-35
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    • 2023
  • Moiré patterns emerge due to the interference between the non-emission area of the LED screen and the grid line in an image sensor of a video recording device when taking a video in the presence of the LED screen. To reduce the moiré intensity, we have fabricated an anti-moiré filter using hollow glass microspheres (HGMs) by slot-die coating. The LED screen has a large non-emission area because of a large pitch (distance between LED chips), causing more severe moiré phenomenon, compared with a display panel having a very narrow black matrix (BM). It is shown that HGMs diffuse light in such a way that the periodicity of the screen is broken and thus the moiré intensity weakens. To quantitatively analyze its moiré suppression capability, we have calculated the spatial frequencies of the moiré fringes using fast Fourier transform. It is addressed that the moiré phenomenon is suppressed and thus the amplitude of each discrete spatial frequency term is reduced as the HGM concentration is increased. Using the filter with the HGM concentration of 9 wt%, the moiré fringes appeared depending sensitively on the distance between the LED screen and the camera are almost completely removed and the visibility of a nature image is enhanced at a sacrifice of luminance.

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지하철 공조실 미세먼지에 대한 자성포집연구 (Study of Magnetic Filtration for Subway MVAC Dust)

  • 박해우;정상귀;조영민
    • 한국입자에어로졸학회지
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    • 제11권2호
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    • pp.37-46
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    • 2015
  • Dust particles, which inflow to the subway mechanical ventilation and air conditioning(MVAC) chamber, contain a fair amount of iron compounds, approximately 25.2w/w%. This work attempted to capture those iron containing dust using magnetic filters. Average magnetization value of the test MVAC dust was 0.012 emu on 5,000 Oe, which could correspond sufficiently with the magnetic interaction. External permanent magnets provided with magnetization of iron mesh screen showing high gradient magnetic field(HGM). It resulted in the capture efficiency with 84.0 ~ 99.7% and 81.2 ~ 99.8% for $PM_{10}$ and $PM_{2.5}$ respectively. Magnetic capture was found to be closely associated with the magnetic intensity, mesh opening size and flow velocity.

Nd:YAG 레이저빔에 의한 PDP 방전셀의 구조 형성 (Formation of PDP cell structure using Nd:YAG laser beam)

  • 안민영;이경철;이홍규;이천
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 디스플레이 광소자 분야
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    • pp.129-132
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    • 2000
  • The PDP(Plasma Display Panel) barrier rib material on the glass substrate was patterned for fabrication of the PDP cell using Nd:YAG laser(1064 nm) which can generate the second(532 nm) and forth(266 nm) harmonic wave by HGM(harmonic generation modules). At a scan speed of 20 ${\mu}m/s$ with the second harmonic wave(532 nm) of Nd:YAG laser, the etching threshold laser fluence of the PDP material was 6.5 $mJ/cm^2$ and a sample(thickness = 180 ${\mu}m$) on the glass substrate was removed clearly at a laser fluence of 19.5 $mJ/cm^2$. In order to increase the throughput of the fabrication we divided a single-beam into multi-beams by using a metal mask between the sample and the focusing lens. As a result, 10 lines of PDP cell were formed by one laser beam scanning at a scan speed of 200 ${\mu}m/s$ and a laser fluence of 2.86 $J/cm^2$.

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