• 제목/요약/키워드: Discharge estimation

검색결과 562건 처리시간 0.032초

방전 드릴을 이용한 미세 홀 관통 공정의 전극 소모량 실시간 예측 (Real-Time Prediction of Electrode Wear for the Small Hole Pass-Through by EDM-drill)

  • 최용찬;허은영;김종민;이철수
    • 한국생산제조학회지
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    • 제22권2호
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    • pp.268-274
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    • 2013
  • Electric discharge machining drill (EDM-drill) is an efficient process for the fabrication of micro-diameter deep metal hole. As there is non-physical contact between tool (electrode) and workpiece, EDM-drill is widely used to machine the hard machining materials such as high strength steel, cemented carbide, titanium alloys. The electro-thermal energy forces the electrode to wear out together with the workpiece to be machined. The electrode wear occurs inside of a machining hole. and It causes hard to monitor the machining state, which leads the productivity and the quality to decrease. Thus, this study presents a methodology to estimated the electrode wear amount while two coefficients (scale factor and shape factor) of the logarithmic regression model are evaluated from the experiment result. To increase the accuracy of estimation model, the linear transformation method is adopted using the differences of initial electrode wear differences. The estimation model is verified through experiment. The experimental result shows that within minute error, the estimation model is able to predict accurately.

수위관측과 수리학적 하도추적에 의한 하천유량 간접추정 (Stream Discharge Estimation by Hydraulic Channel Routing and Stage Measurement)

  • 이상호;강신욱
    • 한국수자원학회논문집
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    • 제34권5호
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    • pp.543-549
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    • 2001
  • 수리학적 하도추적으로부터 하천유량을 간접추정하였다. 짧은 하천구간의 세 지점 연속수위자료와 하천 단면 자료만을 사용하여 조도계수 추정b과 하천유량 계산이 가능하였다. 유량의 간접추정 과정에서, 상류-하류 경계조건을 수위-수위 조건으로 사용하였다. 미국 미시시피 강의 상류 구간 자료가 사용되었고 수리학적 하도추적에는 DWO-PER (operational dynamic wave model)를 이용하였다. DWOPER 모형에서 수정 Newton-Raphson법에 의한 조도계수 추정과정을 개선하기 위하여 SCE-UA 전역최적화 기법을 적용하였으며, SCE-UA 기법의 결과가 적은 오차를 보였다. 특정 홍수에 대하여 유량을 추정한 결과, 몇 개를 제외한 대부분의 계산유량이 10% 이내의 오차를 보였다.

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아산만 배수갑문 확장사업에 따른 아산만 해역의 수리특성 변화 검토 (Estimation for Changing of Hydraulic States Caused by Gate Expansion in Asan Bay)

  • 박병준;송현구;송태관;장은철
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.337-340
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    • 2008
  • The gate expansion was planed to increase discharge capacity of gate structure at sea dike in Asan Bay. So it was estimated for changing of hydraulic states in Pyeongteak Harbor Zone caused by gate expansion, by 2D and 3D CFD Module. In result, influence of gate expansion was less than tidal current and discharge ratio between old gate and new gate was 4:6.

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공동주택의 주방에서 사용되는 시판 환풍기의 환기 성능 평가에 관한 연구 (A Study on the Ventilation Performance Estimation of Marketing Ventilation Fan Used in the Apartment House Kitchen)

  • 송필동;함진식
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2002년도 추계학술발표대회
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    • pp.315-320
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    • 2002
  • Marketing ventilation fan 3 kinds been using in kitchen of apartment house into compensation discharge performance of contaminant measure. When propane gas burns by gas table, did waste heat into measurement compensation with carbon dioxide that it happens. In measured all type of exhaust fan, discharge performance of carbon dioxide and waste heat was high there are been much displacement. Among A, B, C three types, performance of A type exhaust fan was most superior and performance of C type exhaust fan was most poor

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자연하천에서 Chiu의 유속분포와 최대유속 추정을 이용한 유량산정 (Discharge Computation in Natural Rivers Using Chiu's Velocity Distribution and Estimation of Maximum Velocity)

  • 김창완;이민호;유동훈;정성원
    • 한국수자원학회논문집
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    • 제41권6호
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    • pp.575-585
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    • 2008
  • 수자원의 계획 평가 관리 및 수공구조물의 설계를 위해서는 정확하고 신뢰성 높은 유량 자료가 필수적이다. 본 연구에서는 Chiu의 유속분포와 최대유속 추정을 이용하여 하천유량을 계산하는 새로운 방법을 제시하였다. 기존 면적유속법과 비교 검토한 바, 본 연구에서 개발한 방법은 기존 유속면적법과 매우 유사한 하천유량을 보였다. Price-AA를 이용하여 유속을 측정할 경우 측선의 수심에 따라 정해진 지점에서 유속을 측정하여야 하는데, 본 연구에서 제시한 방법을 이용하면 임의의 측선과 측점에서 유속을 측정하여도 정확한 유량계산이 가능하다. 그러나 흐름 단면이 매우 복잡하거나 좌우의 비대칭성이 심한 경우에는 엔트로피 개념의 Chiu의 유속분포가 실제 자연하천의 흐름분포에서 멀어지고 유량산정에 Chiu의 유속분포의 정확도가 떨어지기 때문에 본 연구에서 제시한 방법을 적용하기 어렵다.

면적비를 적용한 미계측유역에서의 설계홍수량 산정방안 (Estimation of Design Flood Discharge by Areal Ratio for Ungauged Basin)

  • 이지호;박재범;송양호;전환돈;이정호
    • 한국습지학회지
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    • 제19권3호
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    • pp.335-344
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    • 2017
  • 본 연구에서는 미계측유역의 설계홍수량을 산정하는 방안으로 유역의 면적비를 적용하는 방안을 제안하였다. 이를 위해 유역출구에서의 실측자료를 활용하여 유출매개변수를 결정하고 면적비를 적용하여 첨두홍수량을 산정하였다. 위 방법론을 검증하기 위해 소하천 유역의 관측유량 및 하천정비종합계획의 설계홍수량과의 비교를 통해 면적비 전이 방법론의 타당성을 검토하였다. 그 결과를 정리하면 다음과 같다. 면적비를 적용한 유출량과 관측유량자료를 비교한 결과 14~25% 정도의 차이를 보였다. 제안된 방법론의 타당성을 재확인하기 위해 하천정비종합계획에서 산정된 첨두유량과 소유역과의 면적비로 계산한 첨두유량을 비교하였다. 이를 위해 31개소의 소하천을 대상으로 설계홍수량을 비교한 결과, 20% 정도의 홍수량의 차이가 발생하였다. 따라서 면적비를 적용한 미계측지역에서의 첨두유량 산정방법론이 타당하다고 판단된다.

병원중심 가정간호관리대상 범위 확대를 위한 기초연구(II) - 자동차보험가입 입원환자를 대상으로 - (A Preliminary Study for Expending of Hospital-Based Home Health Care Coverage - Focused on Car Accident Inpatients Who has the Compensation Insurance -)

  • 박은숙;이숙자;박영주;유호신
    • 가정∙방문간호학회지
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    • 제7권1호
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    • pp.58-72
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    • 2000
  • This study was an attempt to encourage the development of a rehabilitation delivery system and programs as a substitute service for hospitalization on the case of car accident patients, such as hospital based home health care nursing services. Various substitute services for hospitalization are required to curtail the length of stay for inpatients who were hospitalized with car accident compensation insurance. It focused on developing an estimation an early discharge day for car accident inpatients based on detailed statements of treatment for 111 inpatients who were hospitalized at the General Hospital in 1997. This study had four specific purposes as follows. First. to find out the utilization of medical services. Second, to estimate the time of early discharge and income increasing effect based on early discharge for those patients. Third, to identify the factors affecting total medical expenditure and the length of stay for those inpatients. Forth, to figure out the need of utilizing home health care nursing service for accident patients. In order to analyze the length of stay and medical expenditure for inpatients who were hospitalized due to car accidents, the authors conducted micro- and macro-analysis of medical and medical expenditure records. Micro-analysis was done by nominal group discussion of 4 expertise with the critical criteria, such as a decrease in the amount of treatment after surgery, treatments, tests, drugs and changes in the test consistency, drug methods, vital signs, start of ROM exercise, doctor's order, patient's outside visiting ability, and stable conditions. In addition to identifying variables affecting medical expenditure, and the length of stay and income effect due to early discharge day, the data was analyzed with a multiple regression analysis and linear regression analysis model by SPSS-PC for windows and Excell program. Results of this study were as follows. First. the mean length of stay was 50.3 days. whereas the mean length of stay due to early discharge was 34.3 days at the hospital. The estimation of time of early discharge depended on the length of stay. The longer the length of stay, the longer the length of time of early discharge : for instance a length of stay under 10 days was estimated as correlating to a mean length of stay of 6.6 days and early discharge of 6.5. The mean length of stay was 217.4 days and the time of early discharge was 110.1 respectively. The mean medical expenditure per day was found to be 169.085 Won and the mean medical expenditure per day showed negative linear trends according to the length of stay at the hospital. The estimation results of the income effect due to being discharged 16 days early was around 2,244,000 won per bed. However. this sum does not represent the real benefits resulting from early discharge, but rather the income increasing amount without considering medical prime cost in the general hospital. Therefore, further analysis is required on the cost containments and benefits as turn over rate per bed as the medical prime costs. The length of stay was most significant and was positive to the total medical expenditure, as expected. Surgery and patient's residential area was also an important variable in explaining medical expenditure. The level of complications was the most significant variable in explaining the length of stay. There was a high level for need a home health care nursing service which further supports early discharge for accident patients. In addition, when the patient was discharged. they needed follow up care for complications suffered during the car accident. $86.8\%$ of discharged patients responded that they needed home health services after early discharge. From these research findings, the following suggestions have been drawn. Strategies on a health care delivery system must be developed in order to focus on the consumer's needs and being planned for 21 century health policy in Korea. Community based intermediate facilities or home health care should be developed for rehabilitation services as a substitute for hospitalization in order to shorten the length of stay would be. A hospital based home health care nursing service. it would be available immediately to utilize by patients who want rehabilitation services as a substitute for hospitalization with the cooperation of car insurance companies.

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IMPERVIOUS SURFACE ESTIMATION USING REMOTE SENSING IMAGES AND TREE REGRESSIOIN

  • Kim, Soo-Young;Kim, Jong-Hong;Heo, Joon;Heo, Jun-Haeng
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.239-242
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    • 2006
  • Impervious surface is an important index for the estimation of urbanization and environmental change. In addition, impervious surface has an influence on the parameters of rainfall-runoff model during rainy season. The increase of impervious surface causes peak discharge increasing and fast concentration time in urban area. Accordingly, impervious surface estimation is an important factor of urban rainfall-runoff model development and calibration. In this study, impervious surface estimation is performed by using remote sensing images such as landsat-7 ETM+ and high resolution satellite image and regression tree algorithm based on case study area ? Jungnang-cheon basin in Korea.

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국내 지방하천의 유사량과 하상변동 특성에 관한 연구 (A Study of Sediment Discharge and Bed Change Characteristics of the Local Rivers in Korea)

  • 손호근;이정식;신사철;문창건
    • 한국지반환경공학회 논문집
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    • 제15권6호
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    • pp.31-39
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    • 2014
  • 본 연구는 하천 계획수립 및 활용을 위하여 국내 하천을 대상으로 적합한 유사량 추정공식과 장 단기 하상변동을 정량적으로 제시한다. 산지 및 도시하천을 대상으로 유사특성을 분석하고, 총유사량 과 장 단기 하상변동을 검토하기 위하여 기존의 유사량 추정공식과 HEC-RAS 4.1 모형 및 CCHE2D 모형을 적용하였다. 본 연구의 수행으로 인해 얻어진 결과를 요약하면 다음과 같다. 첫째, 수정 Einstein 공식을 적용하여 추정한 총유사량이 해당 하천에 가장 적합한 것으로 판단되었다. 둘째, 대상하천의 중 장기적인 하도관리를 위하여 수위-유량 관계곡선, 부유사량-유량 관계곡선과 총유사량-유량 관계곡선을 제시하였다. 셋째, 단기하상 변동 분석에서는 산지하천이 도시하천보다 하상변동이 크게 발생하였으며, 장기하상 분석에서 도시하천은 현재 안정하상에 도달한 것으로 나타났다.