• 제목/요약/키워드: D-H Parameter

검색결과 476건 처리시간 0.031초

PASS-100을 이용한 응집처리시 물리.화학적 인자의 영향 (Effect of Physicochemical Parameter on PASS-100 Flocculation)

  • 이상일;서인석;박승국
    • 환경위생공학
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    • 제10권2호
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    • pp.30-35
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    • 1995
  • In this research effect of physicochemical parameter on flocculation using PASS-100 were evaluated. pEt flocculant dosage, mixing intensity and detention time were adopted as experimental variables. The physicochemical parameter( p% mixing intensity and mixing time ) were important Parameter on flocculation performance. Effluent pH range for effective flocculation was 4.5-7. Optimum Gt$_{d}$ range was 20,000-30,000 and its range similar to alum flucculation. Rapid mixing was very important parameter to floe formation in PASS- 100 flocculation. Whereas, slow mixing did not affect to the removal efficiency at settling time for 30minute or more.

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CFD PARAMETRIC STUDY FOR 2D WATER ENTRY

  • Lee, H.H.;Rhee, S.H.
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2009년 춘계학술대회논문집
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    • pp.191-195
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    • 2009
  • A parametric study for for the water entry of a two dimensional symmetric wedge with deadrise angle of 10 degrees was carried out to find out the most dominant parameter. Water entry problem with constant velocity is simplified as the stationary wedge in the way of the upcoming water surface. The calculated impact loads showed that the effect of the viscosity was not so important in this problem. For a given grid system a suitable time step size can be found. The most sensitive parameter was found to be the grid size.

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Type 316LN 강의 크리프 수명예측 파라메타의 표준오차 분석 (Standard Error Analysis of Creep-Life Prediction Parameters of Type 316LN Stainless Steels)

  • 김우곤;윤송남;류우석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.19-24
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    • 2004
  • A number of creep data were collected and filed for type 316LN stainless steels through literature survey and experimental data produced in KAERI. Using these data, polynomial equations for predicting creep life were obtained for Larson Miller (L-M), Qrr-Sherby-Dorn (O-S-D) and Manson-Haferd (M-H) parametric methods. In order to find out the suitability for them, the relative standard error (RSE) and standard error of estimate (SEE) values were obtained by statistical process of creep data. The O-S-D parameter showed better fitting to creep-rupture data than the L-M or the M-H parameters, and the three parametric methods did not generate the large difference in the SEE and the RSE values.

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새로운 등가회로정수 산출법에 의한 편측식 직선형 유도전동기의 동특성 해석 (Dynamics Analysis of Single-Sided Linear Induction Motor with New Method of Equivalent Circuit Parameter)

  • 장석명;권정기;조한욱;유대준;이성호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 하계학술대회 논문집 B
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    • pp.1079-1081
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    • 2004
  • Linear induction motors are characterized by a large air gap and, as a result, large leakage inductances. Moreover, due to its unslotted structure and the absence of end rings in the secondary part, the equivalent circuit parameter calculation is very difficult. Therefore this paper introduces the new method of equivalent circuit parameter and analyzes dynamics characteristic of single-sided LIM

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Type 316LN 스테인리스 강의 크리프 수명 예측과 표준오차 분석 (Creep-Life Prediction and Standard Error Analysis of Type 316LN Stainless Steel)

  • 윤송남;김우곤;류우석;이원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1406-1411
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    • 2005
  • The creep rupture data for type 316LN stainless steels were collected through literature survey or experimental data produced in KAERI. Using these data, polynomial equations for predicting creep life were obtained by Larson-Miller (L-M), Orr-Sherby-Dorn (O-S-D) and Manson-Haferd (M-H) etc. time-temperature parametric (TTP) methods. Standard error of estimate (SEE) values for the each parameter was obtained with different temperatures through the statistical process of the creep data. The results of L-M, O-S-D and M-H methods showed good creep-life prediction, but M-H method showed better agreement than L-M and O-S-D methods. Especially, it was found that SEE values of M-H method at $700^{\circ}C$ were lower than that of L-M and O-S-D methods.

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시간-온도 파라미터 방법에 의한 Type 316LN 강의 크리프 수명 예측과 표준오차 분석 (Creep-Life Prediction and Standard Error Analysis of Type 316LN Stainless Steel by Time-Temperature Parametric Methods)

  • 윤송남;류우석;이원;김우곤
    • 대한기계학회논문집A
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    • 제29권1호
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    • pp.74-80
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    • 2005
  • A number of creep rupture data for type 316LN stainless steels were collected through literature survey or experimental data produced in KAERI. Using these data, polynomial equations for predicting creep life were obtained by Larson-Miller (L-M), Orr-Sherby-Dorn (O-S-D) and Manson-Haferd (M-H) parameters using time-temperature parametric (TTP) methods. Standard error of estimate (SEE) values for the each parameter was obtained with different temperatures through the statistical process of the creep data. The results of L-M, O-S-D and M-H methods showed good creep-life prediction, but M-H method showed better agreement than L-M and O-S-D methods. Especially, it was found that SEE values of M-H method at $700^{\circ}C$ were lower than that of L-M and O-S-D methods.

파라메터 변동을 고려한 PMSM의 센서리스 속도제어 (Sensorless Speed Control of PMSM Considering Parameter Variation)

  • 이동희;신규재;권영안
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 A
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    • pp.9-11
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    • 1998
  • Most of sensorless algorithms are based on motor equations including electrical and mechanical parameters. However, parameter variation and uncertain error decrease the accuracy of speed estimation of PMSM. This paper investigates the sensorless speed control of PMSM considering parameter variation. The proposed algorithm use the speed compensator which is robust in parameter variation and error. The simulation and experimental results indicate good performances.

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Gd2O2S:Tb의 동시 계수 도플러 양전자 소멸법에 의한 결함 특성 (Defect Analysis of Gd2O2S : Tb Using Coincidence Doppler Broadening Positron Annihilation Spectroscopy)

  • 이종용;배석환;김재홍;권준현
    • 한국재료학회지
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    • 제16권7호
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    • pp.455-459
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    • 2006
  • Coincidence Doppler Broadening (CDB) of positron annihilation spectroscopy was applied to analyze defects in the chemical state of Department of Physics, $Gd_2O_2S$:Tb intensifying screens. The screen samples were irradiated by 80 MV X-rays in hospital and were used for 0, 2, 4, and 6 years respectively. There was a positive relationship between the S-parameter values and time of exposure to X-rays. Most of the defects were indicated to have been generated by X-rays. A 1D CDB was developed in order to reduce the background noise, and the S-parameter values of the $Gd_2O_2S$:Tb intensifying screens, using the 1D CDB, varied between 0.4974 and 0.4991.

Design of a Robust Target Tracker for Parameter Variations and Unknown Inputs

  • Kim, Eung-Tai;Andrisani, D. II
    • International Journal of Aeronautical and Space Sciences
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    • 제2권2호
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    • pp.73-81
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    • 2001
  • This paper describes the procedure to develop a robust estimator design method for a target tracker that accounts for both structured real parameter uncertainties and unknown inputs. Two robust design approaches are combined: the Mini-p-Norm. design method to consider real parameter uncertainties and the $H_{\infty}$ design technique for unknown disturbances and unknown inputs. Constant estimator gains are computed that guarantee the robust performance of the estimator in the presence of parameter variations in the target model and unknown inputs to the target. The new estimator has two design parameters. One design parameter allows the trade off between small estimator error variance and low sensitivity to unknown parameter variations. Another design parameter allows the trade off between the robustness to real parameter variations and the robustness to unknown inputs. This robust estimator design method was applied to the longitudinal motion tracking problem of a T-38 aircraft.

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