• 제목/요약/키워드: Volume source

검색결과 997건 처리시간 0.023초

Dose calibrator 측정 깊이와 용량의 변화에 따른 선량 값의 성향에 대한 고찰 (A Study on the Tendency of Dose value According to Dose calibrator Measurement Depth and Volume)

  • 김진구;함준철;오신현;강천구;김재삼
    • 핵의학기술
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    • 제24권1호
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    • pp.20-26
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    • 2020
  • 핵의학이란 방사성동위원소 추적자를 인체에 투여하여 관심장기에 대한 형태학적인 정보와 생물학적이고 기능적인 정보를 얻고 평가한다. Dose calibrator는 의료기관에서 단일 핵종의 방사능을 측정하기 위해 사용하는 장비이며, 방사성동위원소의 정확한 용량의 투여는 진단과 치료에 중요한 요인이다. 최근 정량분석을 위한 여러 시스템이 개발되고 있고 ERPF (Effective Renal Plasma Flow), GFR (Glomerular Filtration Rate) 등 정량분석이 필요한 검사에 있어서 정확한 투여 용량 및 재현성 있는 측정이 중요해지고 있다. 따라서 본 논문을 통해 Dose calibrator의 측정 깊이와 용량에 따른 선량 값의 성향을 알아보고 적절한 측정 깊이 및 용량에 대해 알아 보고자 한다. 실험에 사용한 Dose calibrator는 CRC-15R과 CRC-15βeta (Capintec, New Jersey, USA)를 사용하였다. 선원으로는 표준선원(Standard source) 137Cs, 133Ba, 57Co를 사용하였고, 방사성 의약품은 99mTc-pertechnetate를 사용하였다. 표준선원은 측정 깊이만 변화하여 0 cm부터 15 cm까지 1 cm 깊이마다 15회씩 측정했고, 99mTc-pertechnetate의 경우에는 1 mL 주사기로 표준선원과 동일한 깊이로 실험을 진행했고, 용량의 변화를 고려하여 0.1 mL, 0.3 mL, 0.5 mL, 0.7 mL, 0.9 mL로 각 깊이마다 15회씩 측정했다. 표준선원인 137Cs, 133Ba, 57Co의 깊이의 변화에서는 모두 깊이에 따른 선량 값의 변화가 통계적으로 유의한 차이가 있었다(p<0.05). 99mTc-pertechnetate도 깊이에 따른 용량의 변화에서 선량 값이 모두 통계적으로 유의한 차이가 있었다(p<0.05). CRC-15R의 표준선원 비교 그래프에서 137Cs, 133Ba, 57Co는 Plateau를 그리기 시작한 2 cm에서 9 cm까지는 각 선원마다 비교시 통계적으로 유의한 차이가 없었다(p>0.05). CRC-15βeta의 표준선원 비교 그래프에서는 Plateau를 그리기 시작한 영역은 3 cm에서 9 cm로 통계적으로 유의한 차이가 없었다(p>0.05). 99mTc-pertechnetate의 그래프는 0.1 mL에서 1 cm에서 7 cm, 0.3 mL와 0.5 mL에서는 0 cm에서 7 cm, 0.7 mL에서는 0 cm에서 6 cm, 0.9 mL에서는 0 cm에서 5 cm에서 통계적으로 유의한 차이가 나타나지 않았다(p>0.05). 본 연구를 통해 방사성동위원소를 환자에게 주입하거나 정도관리를 진행 시 편차가 적고 재현성을 위해 신뢰할 수 있는 구간을 확인 할 수 있었다. 높이에 따른 변화가 가장 적은 Plateau의 구간이 0.3 mL 혹은 0.5 mL의 용량으로 0 cm 에서 7 cm의 깊이에서 측정한다면, 편차를 최소한으로 줄일 수 있을 것으로 사료된다. 표준선원의 경우에는 본 연구의 결과에 따라 장비마다 Plateau의 변화가 가장 적은 구간의 깊이에서 재현성 있게 측정하는 것이 중요하다고 생각된다. 적절한 구간을 찾아서 재현성 있는 검사를 시행하면 검사의 품질향상 및 피폭선량저감 그리고 진단능을 높이는데 이바지 할 것이라고 생각된다.

Examination of Two-Dimensional Magnetic Properties in a 5-Leg-Different- Volume- V-Connection- Transformer Core

  • Urata Shinya;Shimoji Hiroyasu;Todaka Takashi;Enokizono Masato
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제5B권3호
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    • pp.243-247
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    • 2005
  • The Different-volume- V-connection transformer is known as an electric power source that can supply 3-phase electric power and single-phase electric power at the same time. Usually, we use two single-phase transformers that have different volumes. In this paper, we propose the use of a 3-phase 5-leg transformer with the different-volume- V-connection. And, we examine the magnetic properties of the 5-leg core model with the different-volume- V-connection. The magnetic properties of cores with the different-volume- V-connection are compared with those with the delta-connection. In order to express the magnetic anisotropy of the core materials and to calculate the iron loss directly, the two-dimensional vector magnetic property is considered with the E&SS modeling in the simulation.

Mapping Vegetation Volume in Urban Environments by Fusing LiDAR and Multispectral Data

  • Jung, Jinha;Pijanowski, Bryan
    • 대한원격탐사학회지
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    • 제28권6호
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    • pp.661-670
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    • 2012
  • Urban forests provide great ecosystem services to population in metropolitan areas even though they occupy little green space in a huge gray landscape. Unfortunately, urbanization inherently results in threatening the green infrastructure, and the recent urbanization trends drew great attention of scientists and policy makers on how to preserve or restore green infrastructure in metropolitan area. For this reason, mapping the spatial distribution of the green infrastructure is important in urban environments since the resulting map helps us identify hot green spots and set up long term plan on how to preserve or restore green infrastructure in urban environments. As a preliminary step for mapping green infrastructure utilizing multi-source remote sensing data in urban environments, the objective of this study is to map vegetation volume by fusing LiDAR and multispectral data in urban environments. Multispectral imageries are used to identify the two dimensional distribution of green infrastructure, while LiDAR data are utilized to characterize the vertical structure of the identified green structure. Vegetation volume was calculated over the metropolitan Chicago city area, and the vegetation volume was summarized over 16 NLCD classes. The experimental results indicated that vegetation volume varies greatly even in the same land cover class, and traditional land cover map based above ground biomass estimation approach may introduce bias in the estimation results.

R410A 대체냉매 적용 지열히트펌프 개발 (The development of a ground source heat pump using R410A)

  • 김지동;정봉철;정일권
    • 한국지열·수열에너지학회논문집
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    • 제3권1호
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    • pp.17-22
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    • 2007
  • The growth of domestic energy demand is rapidly increased for the industrialization and the improvement of the living standards. It is also recognised that the importance of the use of environmentally friendly energy and high efficient equipment. Ground Source heat pumps (GSHP) using earth as heat source or sink are outstanding environmentally friendly energy systems which have high thermal efficiency when compared to conventional heating and cooling system. So government employs a policy and increase investment for expanding renewable energy market volume. Especially is established a system for obligatory usage of renewable energy to achieve 5% renewable energy diffusion rate by 2011. And the market demand for the ground source heat pump is rapidly growing due to its strong advantages. However domestic situation usually have been depended on the import of ground source heat pumps. In this paper, the results of development of a ground source heat pump using refrigerant R410A are reported.

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전류제어형 펄스전원장치를 이용한 수산화 가스 발생 특성 연구 (A Study on the Generating feature of Hydrogen Oxygen Gas Using Current Controlled Pulse Power Supply)

  • 양승헌;강병희;전윤석;목형수;최규하
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2002년도 전력전자학술대회 논문집
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    • pp.257-262
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    • 2002
  • Water-Electrolyzed gas is a mixed gas has the constant volume ratio 2 1 Hydrogen and Oxygen gained from electrolyzed water, and it has better characteristics in the field of economy, efficiency of energy, and environmental intimacy than acetylene gas and LPG used for existing gas welding equipment. So nowdays many studies of Water-Electrolyzed gas are progressed, and commercially used as a source of thermal energy for gas welding in the industry. For Water-Electrolyzed Source, it was used diode rectifier or SCR rectifier for get DC source. This method which is not looking to improve a source for impossible current control or voltage and limited control intervals. In this paper, it was relized and designed In source of pulse type for complementing existing - DC source type, also by experiment it was acquired producting characteristics of Hydrogen -Oxygen Gas through feature of source

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구조-음향 상반성 원리를 이용한 공기기인 소음원의 강도 추정 및 소음 합성 (The Use of Vibro-acoustical Reciprocity to Estimate Source Strength and Airborne Noise Synthesis)

  • 김윤재;변재환;강연준;홍진철;권오준;강구태
    • 한국소음진동공학회논문집
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    • 제19권1호
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    • pp.42-49
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    • 2009
  • In this paper, an alternative method was introduced to conduct a transfer path analysis for airborne noise. The method used the transfer function matrix composed of acoustic transfer functions that are referenced by the input voltage of a calibration source. A calibration factor which is converting a virtual voltage to source strength was deduced by vibro-acoustical reciprocity theorem. The calibration factor is then multiplied to the virtual input voltage to estimate the operational source strength. Three loudspeakers were used to noise sources of acrylic half car model. The method was applied to airborne noise transfer path analysis of the half car. The estimated source strength by transfer path analysis was compared the deduced source strength by vibro-acoustical reciprocity to verify the method.

R410A 대체냉매 적용 지열히트펌프 개발 (The development of a ground source heat pump using R410A)

  • 김지동;정봉철;정일권
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 동계학술발표대회 논문집
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    • pp.99-102
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    • 2008
  • The growth of domestic energy demand is rapidly increased for the industrialization and the improvement of the living standards. It is also recognised that the importance of the use of environmentally friendly energy and high efficient equipment. Ground Source heat pumps(GSHP) using earth as heat source or sink are outstanding environmentally friendly energy systems which have high thermal efficiency when compared to conventional heating and cooling system. So government employs a policy and increase investment for expanding renewable energy market volume. Especially is established a system for obligatory usage of renewable energy to achieve 5% renewable energy diffusion rate by 2011. And the market demand for the ground source heat pump is rapidly growing due to its strong advantages. However domestic situation usually have been depended on the import of ground source heat pumps. In this paper, the results of development of a ground source heat pump using refrigerant R410A are reported.

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열원을 가지고 상부가 개방된 사각공간내의 유동에 대한 수치 해석 (A Numerical Analysis in Top Opening Rectangular with a heating source)

  • 배강열;배철환;정효민;정한식
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집B
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    • pp.321-327
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    • 2000
  • This study represents numerical analysis in top opening rectangular with a heating source. The governing equations were solved by a finite volume method, a SIMPLE algorithm was adopted to solve a pressure term. The top boundary with free surface was calculated by energy balance condition. As the results of simulations, the magnitudes of the velocity vectors and isotherms were very small at the lower space of a heating source. The mean Nusselt numbers are increased proportionally to the Grashof number, the heat transfer at Y/H=0.25 was greater than other positions.

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Study on Natural Convection in a Rectangular Enclosure With a Heating Source

  • Bae, Kang-Youl;Jeong, Hyo-Min;Chung, Han-Shik
    • Journal of Mechanical Science and Technology
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    • 제18권2호
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    • pp.294-301
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    • 2004
  • The natural convective heat transfer in a rectangular enclosure with a heating source has been studied by experiment and numerical analysis. The governing equations were solved by a finite volume method, a SIMPLE algorithm was adopted to solve a pressure term. The parameters for the numerical study are positions and surface temperatures of a heating source i.e., Y /H =0.25, 0.5, 0.75 and 11$^{\circ}C$ $\leq$ΔT$\leq$59$^{\circ}C$. The results of isotherms and velocity vectors have been represented, and the numerical results showed a good agreement with experimental values. Based on the numerical results, the mean Nusselt number of the rectangular enclosure wall could be expressed as a function of Grashof number.

농업유역 비점원오염 저감을 위한 자유수면형 인공습지 설계인자 평가 (Assessment of Free Water Surface Constructed Wetland Design Parameters for the Reduction of Agricultural Nonpoint Source Pollution)

  • 장정렬;권순국;최선화
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.637-642
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    • 2005
  • The objective of this study is to evaluate design parameters of free water surface constructed wetland for the reduction of agricultural nonpoint source pollution. From literature review, the key design parameters were selected as influent concentration, influent water volume, hydraulic retention time and wetland system arrangement. The design value for each parameter was established after pilot study. Full-scale constructed wetland on the basis of the designed values was constructed to evaluate those reasonableness. The results of this study showed that the designed values for free water surface constructed wetland were appropriate for the reduction of agricultural nonpoint source pollution.

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