• 제목/요약/키워드: Conversion unit

검색결과 581건 처리시간 0.028초

초단열 열파동의 전파현상을 활용하는 수소저장합금 열변환 시스템의 성능예측을 위한 수치해석적 연구 (A Numerical Study on a Prediction of Performance of the Metal Hydride Thermal Conversion System through the Propagation Phenomena of Superadiabatic Thermal Waves)

  • 김규정;김관영;채재우
    • 대한기계학회논문집B
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    • 제25권4호
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    • pp.572-582
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    • 2001
  • A method of metal-hydride thermal conversion that is an alternative to the traditional method is proposed and investigated. The unit heat pump consists of reactors of two different metal-hydrides are distributed inside parallel channels filled with porous media. The channels are blown through with a heat-transfer agent. Thermal conversion develops as a set of successive heat waves. By a numerical-modeling method it is shown that the maximum thermal effect is attained in synchronous motion of the heat wave and the heat source (or sink) that accompanies the phase transition in the succession of unit metal-hydride pumps. The results are presented in a form convenient for prediction of the thermal and energy efficiency of the proposed thermal-conversion method in real devices.

수치사진측량기법을 이용한 토량환산계수 산정 (The Estimation of Soil Conversion Factor Using Digital Photogrammetry)

  • 김진수;서동주;이종출
    • 한국측량학회지
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    • 제22권4호
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    • pp.339-347
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    • 2004
  • 본 연구에서는 택지조성공사가 실시되고 있는 대규모 현장을 대상으로 절$.$성토부 풍화암의 정확한 토량환산 계수를 산정하고자 한다. 이를 위해, 먼저 대상지 내의 절 성토부 각각 20개소를 굴착하고 굴착 후의 체적을 계산하였다. 그 결과, 교차에 대한 체적의 상대정확도는 평균 0.5%로 산출되었다. 또한, 계산된 체적에 의한 습윤 단위중량과 실내토질시험에 의한 함수비를 이용하여 정확한 토량환산계수를 산정하였다. 산정된 토량환산계수를 모래치환법에 의한 건조단위중량시험에 의해 결정된 토량환산계수와 비교 $.$분석한 결과, 미소한 차이를 나타내었다. 이는 불규칙한 굴착부분의 체적측정을 정밀수치사진측량기법을 적용하였으므로 현장시험의 신뢰성이 높고 토량환산계수 산정을 위한 합리적인 설계방법이라 판단된다.

PRACTICAL MODELLING OF STONE-COLUMN REINFORCED GROUND

  • Tan By S.A.;Tjahyono S.
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2006년도 추계 학술발표회
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    • pp.291-311
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    • 2006
  • The acceleration of consolidation by stone columns was mostly analysed within the framework of a basic unit cell model (i.e. a cylindrical soil body around a column). A method of converting the axisymmetric unit cell into the equivalent plane-strain model would be required for two-dimensional numerical modelling of multi-column field applications. This paper proposes two practical simplified conversion methods to obtain the equivalent plane-strain model of the unit cell, and investigates their applicability to multi-column reinforced ground. In the first conversion method, the soil permeability is matched according to an analytical equation, whereas in the second method, the column width is matched based on the equivalence of column area. The validity of these methods is tested by comparison with the numerical results of unit-cell simulations and with the field data from an embankment case history. The results show that for the case of linear-elastic material modelling, both methods produce reasonably accurate long-term consolidation settlements, whereas for the case of elasto-plastic material modelling, the second method is preferable as the first one gives erroneously lower long-term settlements, where plastic yielding of stone column are ignored.

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건축물 전과정 $CO_2$ 평가를 위한 BIM 라이브러리 개발 (The Development of BIM Library for Building Life Cycle CO2 Assessment)

  • 이병호;홍성욱;신성우
    • 한국디지털건축인테리어학회논문집
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    • 제12권2호
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    • pp.67-76
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    • 2012
  • BIM and its quantity take-off widely apply to the construction projects and LCCO2 Assessment using the BIM's quantity take-off function can be tried recently. Because BIM modeling programs such as Revit and ArchiCAD do not provide adequate library for LCCO2 Assessment, quantity take-off data should be conversed and applied to Carbon Emission Coefficient using Excel program or manual work. Therefore, the purpose of this research is 1) to propose the Unit Conversion Systems for Carbon Emission Coefficient, 2) to provide basic library sets for BIM based LCCO2 Assessment method, and 3) to apply 11 material library sets on a apartment unit plan modeling to pursue the CO2 emission evaluation of the material production in the process of LCCO2 Assessment. Research results showed CO2 emission amount of 458.64kgCO2/m2 from the apartment unit plan modeling.

총량관리 단위유역의 토지이용 변화 및 오염물질 배출형태 분석 (Analysis of Changes in Land Use and Pollution Load for the Unit Watersheds of Total Maximum Daily Loads)

  • 박준대;오승영;최옥연
    • 한국물환경학회지
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    • 제30권2호
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    • pp.128-137
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    • 2014
  • The land use of the unit watersheds should be maintained appropriately in order to keep the load allotment stable for the management of Total Maximum Daily Loads (TMDLs). This study classified the land area in four types and analyzed the use of each land type and its changing pattern by calculating the occupation and conversion ratios for the unit watersheds in three river basins. The forest land showed the greatest occupation ratio with 63.0%, followed by the farm land with 23%, the other area with 8.0% and the site area with 6.0% in 2003. The occupation ratio of the site and the other area increased by 0.4% and 0.2% respectively, and that of the farm and the forest land decreased by 0.4% and 0.2% respectively in 2007. The conversion ratio for the site area ranged from 1.65% to 1.97%, for the farm land from -0.47% to -0.33%, for the forest land from -0.10% to -0.04% and for the other area from 0.17% to 1.97%. It can be inferred that the decrease in the farm and the forest land contributed to the increase in the site area and that the increase in the other area was mainly made by the decrease in the forest land. It could be more effective to take into account the changes in the site area and in the forest land in the process of developing the TMDL plans.

자동차 CO2 배출가스 배출단위 변환방법 고찰 (A Study on the Conversion Method of CO2 Emission Unit of Automobiles)

  • 한정옥;김형태
    • 한국가스학회지
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    • 제23권2호
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    • pp.68-73
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    • 2019
  • 본 연구에서는 차대동력계 시험에서 수집한 자동차 배출가스자료를 엔진동력계에서 측정되는 동력계 단위로 변환하는 방법을 제안하였다. 엔진동력계 시험은 소요시간이 길고 비용이 높아 적용이 제한적일 경우 간편한 방법인 차대동력계 시험이 선호될 수 있다. 환산 방법은 거리기준 배출가스 자료에 모드 엔진효율을 고려하여 동력단위로 환산하는 방법이며 CO2 성분에 대해서 적용한 결과 환산 결과와 측정 결과 사이에 우수한 상관성을 확인하였다. 이 방법을 해외자료에 적용할 경우 CO2 배출성능에 대해 0.1% 이내로 일치함을 보였으나 CO, NOx 및 THC 와 같은 미량 배출성분 들은 같은 환산방법을 적용하기에는 상관성이 다소 떨어지며 추가적인 고려가 필요함을 보였다.

건강보험 환산지수의 유형별 분류방안 (A Classification of Conversion Factors of Relative Values in the National Health Insurance)

  • 김진현;최병호
    • 대한예방한의학회지
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    • 제10권2호
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    • pp.147-158
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    • 2006
  • The purpose of this paper is to review the empirical study results of conversion factors(unit prices) for relative values of health care services in the national health insurance system and establish optimal classification of health care institutions for feasible contract of conversion factors between National Health Insurance Corporation(NHIC) and provider groups, based on legal backgrounds and types of health care service delivery system. some empirical research evidences shows the validity of applying multiple conversion factors to annual contract for reimbursement in the national health insurance. Policy recommendations suggest that clinic, hospital, general hospital, tertiary hospital, dental clinic, oriental medical clinic, pharmacy, and public health centers would be a basic category of provider groups for a meaningful price contract between the NHIC and providers.

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0.18 ${\mu}m$ CMOS 공정을 이용한 SoC용 정전 용량형 멀티 채널 터치 센싱 ASIC의 설계 (A Design of Multi-Channel Capacitive Touch Sensing ASIC for SoC Applications in 0.18 ${\mu}m$ CMOS Process)

  • 남철;부영건;박준성;홍성화;허정;이강윤
    • 대한전자공학회논문지SD
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    • 제47권4호
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    • pp.26-33
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    • 2010
  • 본 논문은 SoC 응용에 가능한 멀티 채널 용량형 터치 센서 유닛과 간단한 공통프로세스 유닛, 스위치 어레이를 포함하여 C-T 방법으로 터치 입력을 처리하는 ASIC을 제안하였다. 본 터치 센서 ASIC은 작은 전류와 칩 면적의 장점을 갖는 C-T 변환 방식에 기반 하여 설계하였으며, 최소 센싱 해상도는 한 카운터 당 41 fF이며, 외부 부품 없이 동작하기 위해 내부 발진기 및 LDO 레귤레이터, $I^2C$를 내장하였다. 본 ASIC은 0.18 um CMOS공정으로 구현되어 있으며, 1.8 V와 3.3 V 전원을 사용한다. 전체 소비 전력은 60 uA이고, 면적은 0.26 $mm^2$이다.