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보 건설에 따른 영산강의 조류 발생 및 환경 변화: 수질측정망 장기 자료 분석 (The Change in Patterns and Conditions of Algal Blooms Resulting from Construction of Weirs in the Youngsan River: Long-term Data Analysis)

  • 신용식;유행선;이학영;이다혜;박건우
    • 생태와환경
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    • 제48권4호
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    • pp.238-252
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    • 2015
  • 4대강 사업의 일환으로 추진된 보 건설이 영산강의 조류발생 형태와 제반 환경조건에 미치는 영향을 조사하기 위해 장기 (2001~2014년) 자료 (환경부 물환경정보시스템)를 분석하였다. 분석 항목으로 조류 발생의 형태를 파악할 수 있는 엽록소 ${\alpha}$와 환경인자인 부유물질, 암모늄, 질산염, 인산염, 총 질소, 총 인, N : P ratio 등이다. 조사 정점은 최상류에 위치한 담양 (DY)에서 하류의 무안1 (MA1)까지 포함 (총 12개)한다. 분석 항목별로 시간적 분포를 시계열로 분석하였고, 건설 전과 후의 직접적인 비교를 위해 전과 후 3년간 자료 (2006~2008년, 2012~2013년)를 Box-Whisker Plot으로 도시하여 분석하였다. 또한 항목들 간의 상관성 분석 (Pearson's correlation analysis)도 실시하였다. 분석 결과, 수층의 탁도를 결정하는 부유물질은 보 건설 기간 중에 부유물질 농도가 보 건설 전에 비해 거의 모든 정점에서 상당 폭 증가한 반면 건설 이후에는 상류 및 중류에 위치한 정점들을 중심으로 확연하게 감소하였다. 암모늄은 건설 이전에 비해 건설 이후 증가하는 경향을 보인 반면, 나머지 영양염은 감소하였고 이로 인해 N : P ratio가 증가하는 경향을 보였다. 엽록소 ${\alpha}$는 건설 중에는 모든 정점에서 감소하였으나, 건설 후에 부유물질 (탁도)이 감소하였던 정점에서 건설 전에 비해 확연히 증가하는 형태를 보여 주었다. 이는 영산강에서 보 건설 이후 인산염과 같은 영양염이 감소했지만, 동시에 탁도가 감소하면서 조류가 대발생 할 수 있는 환경이 조성되었음을 제시하는 결과라 할 수 있다

어도를 통과하는 어류의 형태 체형비 평가 (Assessment of fish fineness ratios passing through a fishway)

  • 문운기;배대열;김도현;신현범;서정빈;임경훈;이의행;유재상;안광국;김재구
    • 환경생물
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    • 제37권4호
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    • pp.726-734
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    • 2019
  • 본 연구에서 국내 어류 분류군별 체형비(Fineness Ratios; FR)를 분석한 결과 일부 잉어과와 납자루아과, 꺽지과, 검정우럭과 등의 어류 체형비가 상대적으로 낮았고, 그 외 분류군별 어류의 체형비는 4.5 이상으로 대부분 유영력이 뛰어난 것으로 나타났다. 유영성 어류를 대상으로 체장-체고비에 따른 서식지 선호를 분석한 결과 크게 3가지 어종타입은 구분되었다. 유영력이 낮은 납자루-붕어형은 체형비는 2.1~3.3 범위이며, 유선형의 비율을 가지는 피라미-참갈겨니형은 체형비가 3.7~5.2 범위였다. 은어-누치형은 체장이 체고의 5배 이상으로 유영력이 뛰어난 형태를 가지고 있었다. 어류 체형비에 따른 서식지 유형을 구분하면 붕어-납자루형은 흐름이 완만한 소(Pool habitat)형태의 서식지를 선호하는 어종 우세하였고, 반면 피라미-참갈겨니형, 은어-누치형의 경우 유속이 빠른 여울형서식지(Riffle habitat)를 선호하는 어종들로 구성되었다. 조사기간 동안 어도를 이용한 어류의 상대풍부도를 분석한 결과, 대부분의 어종들이 피라미-참갈겨니, 은어-누치형에 속하는 유영성이 높은 어류들로 확인되었다. 어도 내 유속이 0.5~1.0 m s-1 범위에서 이용 어종의 FRs는 4.5~5.0 범위로 나타나 대부분 유영성 어종들이 어도를 주로 이용하는 것으로 나타났다.

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제27권7호
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

설비공학 분야의 최근 연구 동향 : 2012년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2012)

  • 한화택;이대영;김사량;김현정;최종민;박준석;김수민
    • 설비공학논문집
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    • 제25권6호
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    • pp.346-361
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    • 2013
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2012. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. The conclusions are as follows : (1) The research works on thermal and fluid engineering have been reviewed as groups of fluid machinery, pipes and valves, fuel cells and power plants, ground-coupled heat pumps, and general heat and mass transfer systems. Research issues are mainly focused on new and renewable energy systems, such as fuel cells, ocean thermal energy conversion power plants, and ground-coupled heat pump systems. (2) Research works on the heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer, and industrial heat exchangers. Researches on heat transfer characteristics included the results for natural convection in a square enclosure with two hot circular cylinders, non-uniform grooved tube considering tube expansion, single-tube annular baffle system, broadcasting LED light with ion wind generator, mechanical property and microstructure of SA213 P92 boiler pipe steel, and flat plate using multiple tripping wires. In the area of pool boiling and condensing heat transfer, researches on the design of a micro-channel heat exchanger for a heat pump, numerical simulation of a heat pump evaporator considering the pressure drop in the distributor and capillary tubes, critical heat flux on a thermoexcel-E enhanced surface, and the performance of a fin-and-tube condenser with non-uniform air distribution and different tube types were actively carried out. In the area of industrial heat exchangers, researches on a plate heat exchanger type dehumidifier, fin-tube heat exchanger, an electric circuit transient analogy model in a vertical closed loop ground heat exchanger, heat transfer characteristics of a double skin window for plant factory, a regenerative heat exchanger depending on its porous structure, and various types of plate heat exchangers were performed. (3) In the field of refrigeration, various studies were executed to improve refrigeration system performance, and to evaluate the applicability of alternative refrigerants and new components. Various topics were presented in the area of refrigeration cycle. Research issues mainly focused on the enhancement of the system performance. In the alternative refrigerant area, studies on CO2, R32/R152a mixture, and R1234yf were performed. Studies on the design and performance analysis of various compressors and evaporator were executed. (4) In building mechanical system research fields, twenty-nine studies were conducted to achieve effective design of mechanical systems, and also to maximize the energy efficiency of buildings. The topics of the studies included heating and cooling, HVAC system, ventilation, renewable energy systems, and lighting systems in buildings. New designs and performance tests using numerical methods and experiments provide useful information and key data, which can improve the energy efficiency of buildings. (5) In the fields of the architectural environment, studies for various purposes, such as indoor environment, building energy, and renewable energy were performed. In particular, building energy-related researches and renewable energy systems have been mainly studied, reflecting interests in global climate change, and efforts to reduce building energy consumption by government and architectural specialists. In addition, many researches have been conducted regarding indoor environments.

포유동물의 생식과 페로몬 (Mammalian Reproduction and Pheromones)

  • 이성호
    • 한국발생생물학회지:발생과생식
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    • 제10권3호
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    • pp.159-168
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    • 2006
  • 설치류를 포함한 대부분의 포유동물은 페로몬 반응을 중개하는 두 개의 화학감각 시스템(chemosensory system)을 갖고 있는데, 각각 주후각시스템(main olfactory system, MOS)과 부후각시스템(accesory olfactory system, AOS)이다. MOS에 속하는 화학감각뉴런들은 주후각 상피 내에 위치하며, AOS에 속하는 화학감각뉴런들은 비강 윗부분의 서골비기관(vomeronasal organ, VNO)에 위치한다. 공기 중의 비휘발성 페로몬 성분들은 구개 위쪽으로 열린 관을 통해 VNO의 내강으로 이동한다. 페로몬 수용체 단백질들은 크게 두 개의 슈퍼패밀리 V1R과 V2R로 나뉘는데, 이들은 구조적으로 큰 차이가 있으며 MOS에서 발현되는 후각 수용체들과는 무관하다. 이들은 7개의 막관통 도메인을 갖는 G-단백질 결부 단백질(seven transmembrane domain G-protein coupled proteins, V1R은 $G_{{\alpha}i2}$와, 그리고 V2R은 $G_{0\;{\alpha}}$와 연관)이다. V2R은 비고전적 MHC Ib 유전자 산물인 M10과 기타 8개의 M1 패밀리 단백질들과 함께 작용한다. 그 외 VNO 뉴런의 중요한 구성 분자는 TrpC2로, 이는 transient receptor potential(TRP)의 양이온 채널 단백질이며 세포내 신호전달과정에서 중요한 역할을 할 것으로 추정된다. 포유동물의 화학적 의사소통과정에서 페로몬은 작용 모드 또는 효과에 따라 4종류로 분류할 수 있는데, 프라이머(primer), 신호자(signaler), 조정자(modulator) 그리고 방출자(releaser)이다. 근본적으로 이들 화학신호에 대한 반응들은 개체 간, 심지어는 한 개체 내에서도 다양할 수 있다. 이러한 다양성은 페로몬이 스테로이드 호르몬들과 함께 또는 단독으로, 신경전달물질들과 같은 비스테로이드 요인들의 후각정보 처리 과정에 미치는 각종 조절의 차이에 의해 나타날 수 있다. 이러한 조절은 유리한 사회적, 환경적인 조건들을 갖도록 수용자의 생식 축에 미치는 영향을 증강 또는 촉진한다. 가장 좋은 예는 수컷 생쥐의 소변 중의 테스토스테론 의존적인 주요 요단백질(major urinary proteins, MUPs)에 의한 임신방지효과(Bruce 효과)이다. 흥미롭게도 생쥐 GnRH 뉴런은 냄새와 페로몬 양자 모두로부터 페로몬 신호를 수용하는 것 같다. 비록 상당한 논란의 소지는 있지만, 그간의 연구들은 생식과 기타 여러 기능들 사이에 복잡한 상호교차 관계가 있음을 시사한다. 여기서 GnRH 뉴런은 다양한 원천으로부터의 정보를 통합하고, 다시 다양한 뇌기능을 조절하는 것으로 보인다.

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정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) II. 흉부단극유도(胸部單極誘導)의 파형(波形)과 전위(電位) (Studies on electrocardiogram of the normal Korean native cattle II. Wave forms and amplitudes of the unipolar precordial chest leads)

  • 최인혁;김수용;김남수;서두석
    • 대한수의학회지
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    • 제33권4호
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    • pp.735-746
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    • 1993
  • Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{\pm}31.0{\mu}V$ and $76.0{\pm}30.7{\mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{\pm}29.4{\mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{\pm}154.0{\mu}V$ to $648.2{\pm}146.2{\mu}V$(mean of $418.8{\pm}139.4{\mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{\pm}139.8{\mu}V$ and $-399.2{\pm}226.8{\mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{\pm}142.1{\mu}V$, $271.6{\pm}139.9{\mu}V$ and $552.4{\pm}132.7{\mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{\pm}93.7{\mu}V$ $103.7{\pm}64.43{\mu}V$ and $111.8{\pm}39.3{\mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{\pm}82.1{\mu}V$ and $-280.3{\pm}107.2{\mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{\pm}33.1{\mu}V$, $0.9{\pm}23.1{\mu}V$, $10.9{\pm}28.6{\mu}V$, $5.8{\pm}28.3{\mu}V$ and $-34.7{\pm}48.4{\mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively.

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정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) I. 표준지유도(標準肢誘導) (Studies on electrocardiogram of the normal Korean native cattle I. Standard limb leads)

  • 최인혁;정인성;김남수;서두석
    • 대한수의학회지
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    • 제33권4호
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    • pp.719-734
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    • 1993
  • The electrocardiographic(ECG) parameters on the standard limb leads in the normal Korean native cattle have been measured with a 3 channel Electrocardiograph built in a computed analysis. The study was conducted on the animals 98 heads of mean age of 17.7 months. Conduction parameters, waves, intervals and segments have been recorded. The recordings were analyzed as to shape and amplitude of the P and T waves and the components of the QRS complex. Heart rate was recorded by the Electrocardiogram which were a mean of $80.4{\pm}11.6beats/min$. And the younger had a higher heart rate than the older one. Average conduction times in the RP, the QRS complex and the QTc interval recorded $166.7{\pm}23.1msec.$, $79.7{\pm}8.8msec.$ and $395.5{\pm}30.4msec.$, in the P and T wave duration recorded $70.1{\pm}13.5msec.$ and $97.6{\pm}16.9msec.$, and in the PR and ST segment duration recorded $97.9{\pm}23.5msec.$ and $173.9{\pm}40.3msec.$, respectively. The wave forms in each lead observed various types. The amplitudes of wave type showed the highest frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of the positive type showed the frequency of 65.3%, 82.7% and 52.0% in leads I, II and III that were $103.1{\pm}47.8{\mu}V$, $115.2{\pm}37.3{\mu}V$ and $67.4{\pm}26.9{\mu}V$, and it showed the frequency of 54.1% and 85.7% in the leads aVL and aVF that were $63.7{\pm}23.0{\mu}V$, $88.0{\pm}83.6{\mu}V$, respectively. Average amplitude of the negative type showed the frequency of 78.6% in lead aVR which was $99.3{\pm}38.0{\mu}V$. 2. Average amplitude of the QRS complex were from $362.8{\pm}177.7{\mu}V$ to $532.8{\pm}253.9{\mu}V$(mean of $449.1{\pm}57.2{\mu}V$) that in all leads except lead I were manifested the Low-Voltage QRS complex(below 0.5mV). Average amplitudes of each wave type in the QRS complex aere $-50.2.4{\pm}258.2{\mu}V$ and $-428.6{\pm}195.1{\mu}V$ in the QS groups type that showed a frequency of 66.3%, 70.4% in the leads I and aVL, were $451.1{\pm}20.4.0{\mu}V$, $387.6{\pm}175.8{\mu}V$ and $299.3{\pm}146.5{\mu}V$ in the R groups type that showed a frequency of 48.0%, 53.1% and 34.7% in the leads III, aVR and aVF, and were $-307.5{\pm}180.3{\mu}V$, $201.4{\pm}77.2{\mu}V$ in the QR wave type which showed a frequency of 39.8% in lead II, respectively. 3. In T wave, amplitude of the positive type showed the frequency of 50.0%, 82.7%, 51.0% and 57.1% in leads II, III aVR and aVF which were $214.9{\pm}115.6{\mu}V$, $188.5{\pm}119.3{\mu}V$, $191.0{\pm}93.7{\mu}V$ and $165.7{\pm}91.9{\mu}V$, and the negative type showed a frequecny of 66.3% and 72.5% in leads I and aVL. that were $221.3{\pm}112.5{\mu}V$, $-173.6{\pm}86.7{\mu}V$, respectively. 4. Amplitude of ST segment in leads I, II and III were a mean of $-12.2{\pm}37.2{\mu}V$, $17.5{\pm}42.6{\mu}V$ and $28.3{\pm}40.4{\mu}V$, in leads aVR, aVL and aVF were $-3.9{\pm}32.5{\mu}V$, $-15.9{\pm}35.6{\mu}V$ and $26.2{\pm}37.5{\mu}V$, respectively.

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설비공학회 분야의 최근 연구 동향 : 2015년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research : A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2015)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제28권6호
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    • pp.256-268
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    • 2016
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2015. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering were carried out in the areas of flow, heat and mass transfer, cooling and heating, and air-conditioning, the renewable energy system and the flow inside building rooms. Research issues dealing with air-conditioning machines and fire and exhausting smoke were reduced. CFD seems to be spreading to more research areas. (2) Research works on heat transfer area were carried out in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the economic analysis of GHG emission, micro channel heat exchanger, effect of rib angle on thermal performance, the airside performance of fin-and-tube heat exchangers, theoretical analysis of a rotary heat exchanger, heat exchanger in a cryogenic environment, the performance of a cross-flow-type, indirect evaporative cooler made of paper/plastic film. In the area of pool boiling and condensing, the bubble jet loop heat pipe was studied. In the area of industrial heat exchangers, researches were performed on fin-tube heat exchanger, KSTAR PFC and vacuum vessel at baking phase, the performance of small-sized dehumidification rotor, design of gas-injection port of an asymmetric scroll compressor, effect of slot discharge-angle change on exhaust efficiency of range hood system with air curtain. (3) In the field of refrigeration, various studies were carried in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, a cold-climate heat pump system, $CO_2$ cascade systems, ejector cycles and a PCM-based continuous heating system were investigated. In the alternative refrigeration/energy system category, a polymer adsorption heat pump, an alcohol absorption heat pump and a desiccant-based hybrid refrigeration system were investigated. In the system control category, turbo-refrigerator capacity controls and an absorption chiller fault diagnostics were investigated. (4) In building mechanical system research fields, eighteen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the user and location awareness technology applied dimming lighting control system, the lighting performance evaluation for light-shelves, the improvement evaluation of air quality through analysis of ventilation efficiency and the evaluation of airtightness of sliding and LS window systems. The subjects of building energy were worked on the energy saving estimation of existing buildings, the developing model to predict heating energy usage in domestic city area and the performance evaluation of cooling applied with economizer control. The studies were also performed related to the experimental measurement of weight variation and thermal conductivity in polyurethane foam, the development of flame spread prevention system for sandwich panels, the utilization of heat from waste-incineration facility in large-scale horticultural facilities.

자기공명확산강조영상에서 SE-EPI 와 SSH-TSE 기법을 이용한 영상의 질 평가 (Evaluation of Image Quality using SE-EPI and SSH-TSE Techniques in MRDWI)

  • 구은회
    • 한국방사선학회논문지
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    • 제15권7호
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    • pp.991-998
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    • 2021
  • 본 연구의 목적은 뇌 자기공명영상에서 확산강조 검사에 대한 SE-EPI 기법과 SSH - TSE 기법에 대한 영상의 질을 알아보고자 한다. MRDWI 검사를 시행한 환자를 무작위로 선정한 PACS 전송 데이터 35명 중 정상 남자 12명, 정상 여자 13명, 뇌경색 10명 중 남자 5 여자 5, 평균나이 68 ± 7.32를 대상으로 데이터를 분석하였다. 사용된 장비는 Ingenia CX 3.0T을 사용하였고 데이터 획득을 위하여 SSH-TSE, SE-EPI 펄스시퀀스와 32 Channel Head Coil를 이용하였다. 영상평가는 paired t-test와 Wilcoxon 검정을 하였으며 p 값이 0.05 이하 일 때 유의성이 있는 것으로 간주하였다. DWI 영상에 대한 SNR대한 정량적 분석 결과 ADC(s/mm2), Diffusion b=0, 1000영상에서 4 부위(WM, GM, BG, Cerebellum)의 평균 및 표준편차 값이 SE-EPI기법(ADC:120.50 ± 40, b=0: 54.50 ± 35.91, b=1000: 91.61 ± 36.63)이 SSH-TSE(ADC:99.69 ± 31.10, b=0: 43.52 ± 25.00 , b=1000: 60.74 ± 24.85) 보다 높게 나타났다(p<0.05). GM-WM, BG-WM 부위에 대한 CNR 값 또한 SE-EPI기법(ADC:116.08 ± 43.30 , b=0: 27.23 ± 09.10 , b=1000: 78.50 ± 16.56)이 SSH-TSE(ADC:101.08 ± 36.81, b=0: 23.96 ± 07.79 , b=1000: 74.30 ± 14.22) 보다 높게 나타났다(p<0.05). 관찰자의 시각적 평가로서 SSH-TSE, SE-TSE에 대한 Ghost 인공물 자화율 인공물, 전반적인 영상의질 모두 SSH-TSE 기법이 높은 결과를 얻었다(ADC:3.6 ± 0.1, 2.8 ± 0.2, b=0: 4.3 ± 0.3, 3.4 ± 0.1 b=1000: 4.3 ± 0.2, 3.5 ± 0.2, p=0.000). 결론적으로, SSH-TSE, SE-EPI를 사용한 SNR, CNR 측정에서 SE-EPI 기법이 우위의 결과를 얻었다. 정성적 분석에서는 펄스시퀀스 특성에 따라 SSH-TSE 펄스시퀀스가 높은 결과를 얻었다.

인공위성 원격탐사를 이용한 백두산 화산 감시 연구 리뷰 (A Review on Monitoring Mt. Baekdu Volcano Using Space-based Remote Sensing Observations)

  • 홍상훈;장민정;정성우;박서우
    • 대한원격탐사학회지
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    • 제34권6_4호
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    • pp.1503-1517
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    • 2018
  • 백두산은 중국과 북한의 국경 경계에 위치하고 있는 성층화산으로 신생대 올리고세 이후 주요 분화 단계를 거쳐 형성된 것으로 알려져 있다. 2010년 이후 마그마 재활동으로 인한 백두산 화산활동 여부에 대한 관심이 증대되고 있다. 백두산 화산 활동을 감시하기 위한 연구는 기상청, 한국지질자원연구원 등 국가기관 중심으로 활발히 수행되고 있다. 2018년에는 한-중 백두산 공동 관측 장기연구 과제가 선정되었으며 이로부터 화산특화연구센터가 설립되기도 하였다. 그러나 백두산은 우리나라로부터 지리적으로 멀리 떨어져 있어 접근에 대한 제약이 있을 뿐만 아니라 백두산 화산 주변에 설치되어 있는 현장 관측 장비로부터 수집된 현장 자료의 공유 혹은 접근이 쉽지 않은 상황이다. 원격탐사는 직접적인 물리적 접촉 없이 대상 물체에 대한 특성을 원격으로 측정하는 수단으로서, 대상물의 관측을 위해 자동차, 무인기, 항공기, 인공위성 등 여러 형태의 플랫폼이 사용된다. 지난 수십 년 간, 다양한 파장 대역에서의 전자기파를 이용한 원격탐사 자료를 활용하여 화산 감시 연구가 수행되어 왔다. 특히 레이더 원격탐사는 주야조건, 기상조건에 관계없이 자료를 획득할 수 있을 뿐만아니라 위상정보를 이용한 레이더 위상간섭기법을 통한 미세 지표 변위 관측이 가능하여 매우 널리 이용되고 있는 화산 감시 기술이다. 본 논문의 목적은 백두산 화산 관측을 위해 수행된 기존 원격탐사 연구 문헌을 수집하고 동향을 파악하는 것이다. 또한 지속적인 화산 감시를 위한 가용 영상레이더 위성정보를 조사하여 향후 이를 바탕으로 백두산 화산 지표 변위의 주기적 탐지 연구를 수행하는데 활용할 예정이다.