• 제목/요약/키워드: Operating Characteristic Function

검색결과 127건 처리시간 0.026초

중국의 표준화 제도 및 운영시스템에 관한 연구 (A Study on the Standardization System in China)

  • 박혜숙;윤인찬;조남호
    • 산업경영시스템학회지
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    • 제25권6호
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    • pp.59-72
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    • 2002
  • Along with the enlargement of WTO, issues about standardization activity are more and more become concerning object worldwide. Countries launch the work that putting the standardization in order, such as re-establishing their standardization strategy. With the chance of entering WTO, China is promoting the rebuilding of standardization system in order to conform to international standardization system. Thus, in this paper, research make it clear that the variation of circumstance of standardization activity, the importance of the standardization activity, and the international movement, in the meantime, it surveyed the development course of standardization activity and it's present operating system. By this means, it concludes the problems of present operating system and implies the improving scheme. Further more, this paper implies Chinese characteristic standardization system which conform with WTO/TBT and international standardization system. Firstly, through the comprehensive analysis on standardization system, it figures out the main function of relevant organizations in each working stage. Secondly, this paper makes a system model composed of possible three stage, and setup items needs promotion and main target in each stage. Finally, this paper point out the development direction of standardization system, it also implies it's limitation and the later possible research topic in this field.

대학기록물관리시스템 모델링(Modeling)을 위한 기초 연구 (A preliminary study on modeling for University Archives Management System)

  • 이아현
    • 기록학연구
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    • 제9호
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    • pp.164-189
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    • 2004
  • This paper illustrates preliminary modeling for University Archives Management System(UAMS) construction. University must install Intermediate Archives(records and archives) facilities and management system by Public Records and Archives Act(PRA). But it is very difficult to generalize UAMS because University co-exists public and its own characteristic. For UAMS modeling, this paper first identifies University document's production creators and documental boundary. Then it is studied how University archives management is operated and what archives system by PRA means in University. Second systematic connection plan of Intermediate Archives(records and archives) facilities and manuscripts management is surveyed through National Universities and complementary things are presented. Finally through the above study UAMS model is suggested as future-oriented University archives management. UAMS model suggested from this study includes as follows. First manuscripts management as present Records and Archives system's standard function extension. Second manuscripts management system as system management area's extension using in Universities. It is desirable to extend to expert archives system. Finally integrated operating system model for using actively records, archives and manuscripts management systems operating in Universities.

평균 샘플 수 최소화를 통한 계량형 반복 샘플링 검사의 설계 (A Variables Repetitive Group Sampling Plan for Minimizing Average Sample Number)

  • 박희곤;문영건;전치혁;;이재욱
    • 대한산업공학회지
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    • 제30권3호
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    • pp.205-212
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    • 2004
  • This paper proposes the variables repetitive group sampling plan where the quality characteristic following normal distribution has upper or lower specification limit. The problem is formulated as a non-linear programming problem where the objective function to minimize is the average sample number and the constraints are related to lot acceptance probabilities at acceptable quality level (AQL) and limiting quality level (LQL) under the operating characteristic curve. Sampling plan tables are constructed for the selection of parameters indexed by AQL and LQL in the cases of known standard deviation and unknown standard deviation. It is shown that the proposed sampling plan significantly reduces the average sample number as compared with the single or the double sampling plan.

열병합/산업용 보일러 화로에서의 연소 해석 (Modeling of Combustion in Co-Generation / Industrial Boiler Furnace)

  • 김병윤;박부민;이경모
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집B
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    • pp.842-846
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    • 2001
  • Our company produces boilers for industrial usages or power plants. The aim of this study is to investigate the flame structure, heat transfer to evaporator tube wall and NOx emission in the furnaces. Also we are to derive correct FEGT(Furnace Exit Gas Temperature) characteristic curve. When we design furnace and superheater, economizer etc. FEGT characteristic curve is very important factor for optimum design. We calculated turbulent reacting flow, heat transfer and NOx emission in furnace by using numerical modeling with the help of commercial code. Three dimensional steady state calculation is done. k-e turbulence model and equilibrium chemistry combustion model with $\beta-probability$ density function is used. To calculate radiation heat transfer discrete ordinates model is used. And we measured FEGT at several operating plants. Measurement is done by R-type thermocouple. Radiation shield is attached to the thermocouple to prevent radiation effect. Measured and calculated results show good agreement. And we could understand the flame structure and NOx formation positions in each furnaces.

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Characteristic Analysis and Experimental Verification of the Axially Asymmetric Structured Outer-Rotor Type Permanent Magnet Motor

  • Seo, Myung-Ki;Lee, Tae-Yong;Park, Kyungsoo;Kim, Yong-Jae;Jung, Sang-Yong
    • Journal of Electrical Engineering and Technology
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    • 제11권4호
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    • pp.898-904
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    • 2016
  • In this study, we have dealt with a design characteristic of outer-rotor type permanent magnet (PM) motor applied for Engine Cooling Fan (ECF). When we design a motor with structure like this type, it is required as a requisite to consider 3-Dimensional (3-D) effect by implementing a non-linear Finite Element Analysis (FEA) due to a yoke-ceiling, which is perpendicular to the axis of rotation. We have analyzed identical models under three different conditions. The analysis has been performed through a non-linear 2-Dimensional (2-D) and 3-D FEA. Finally, the results have been compared with Back Electro-Motive Force (BEMF) value of actual motor model. As a result, a yoke-ceiling function as an additional flux path and the operating point on B-H curve of rotor material is shifted to non-saturation region relatively. Accordingly, magnetic flux linkage can be increased and motor size can be decreased under same input condition to satisfy ECF specification, such as torque.

Clinical Utility of Liver Stiffness Measurements on Magnetic Resonance Elastrography in Patients with Hepatocellular Carcinoma Treated with Radiofrequency Ablation

  • Kim, Ji Eun;Lee, Jeong Min;Lee, Dong Ho;Chang, Won;Yoon, Jeong Hee;Han, Joon Goo
    • Investigative Magnetic Resonance Imaging
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    • 제20권4호
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    • pp.231-240
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    • 2016
  • Purpose: To determine whether liver stiffness (LS) measured by magnetic resonance elastography (MRE) can predict the outcome of radiofrequency ablation (RFA) in hepatocellular carcinoma (HCC) patients. Materials and Methods: A total of 107 patients with Child-Pugh class A liver function who were treated with RFA for single HCC and who had undergone a gradient-echo MRE within 6 months before RFA were included. We evaluated the relationship between the LS values and the ablation volume, local tumor progression (LTP), and intrahepatic distant recurrence (IDR). We also constructed receiver operating characteristic (ROC) curves to examine the role of LS in predicting liver function deterioration, which was defined as an increase of Child-Pugh score by one point or more at 1 year after RFA. Results: There was no significant correlation between LS and ablation volume, and neither time to LTP nor IDR was associated with LS. Among the 66 patients who did not have recurrence 1 year after RFA, 5 patients (7.6%) developed liver function deterioration. A high LS value was significantly associated with development of liver function deterioration after RFA and the area under the ROC curve was 0.764 (95% CI 0.598-0.929, P = 0.003). Conclusion: LS measured by MRE could not predict ablation volume and tumor recurrence. However, high LS values were significantly associated with development of liver function deterioration.

불량갯수에 대한 축차 샘플링검사 (Sequential Sampling Inspection Plans for Defectives)

  • 이재헌;박창순;박종태
    • 품질경영학회지
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    • 제24권4호
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    • pp.1-13
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    • 1996
  • The sequential sampling inspection method is an extension of the double-sampling and multiple-sampling methods and its theory is based on the sequential probability ratio test(SPRT). In this paper, the characteristics of SPRT for testing the propotion of defectives are approximated by using the estimated excess over the boundaries. The use of the estimated excess shows good performances in estimating the operating characteristic function and the average sample number of SPRT compared to the method by neglecting the excess. It also makes it possible to determine the boundary values which satisfy the desired error probabilities.

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Step 가변형 MPPT 제어기법과 DVR을 적용한 계통연계형 태양광 발전 시스템 (Grid-Connected Photovoltaic System Applying the Step Variable MPPT Control and DVR)

  • 이용식;정성원;김재현
    • 조명전기설비학회논문지
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    • 제26권8호
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    • pp.42-49
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    • 2012
  • Grid-connected photovoltaic generator system requires high performance PCS(Power Conditioning System) according to the standard of 'Distributed Generation Grid-Connected Technology Standards'. This paper presents the MPPT control method which improves output efficiency through fast tracking to the maximum power point of PV and a reduced self-excited vibration. Secondly, in this paper DVR function was applied to PCS to compensate the voltage sag frequently happening for a power system. The proposed PCS control is analyzed and compared to conventional PCS operating characteristic, the various insolation and loads, and voltage sag condition through PSIM tool. It proves the utility.

Surge arrester용 surge counter의 동작 특성 평가 (Operating characteristic of surge counter)

  • 김석수;최익순;조동환;이강섭;박태곤
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.1134-1137
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    • 2004
  • The main function of surge counter is knowing the times of surge flowed in, which is installed under surge arrester. Two methods are presented in this paper to get the electric power for mechanical movement and detect the surge with surge counter. One is using ZnO varistor resister and the other is using the current transformer.

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누적합 통계량을 이용한 축차검정에 관한 연구 (A study on sequential test based on cumulative sum of statistics)

  • 박창순;최기철
    • 응용통계연구
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    • 제3권1호
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    • pp.105-120
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    • 1990
  • 이 논문에서는 통계량의 누적합을 이용하여 누적합 검정을 정의하고 그 특성에 대해 연구하였으며, 축차확률비 검정과의 상대효율을 정의하였다. 누적합 검정의 검사특성함수와 평균표본수는 Wald의 근사공식과 Wiener과정 근사에 의해 표현될 수 있음을 보였다. 또한 누적합 검정에서 축차확률비 검정과 점근적으로 동일한 효율성을 나타내는 통계량을 선정할 수 있음을 보였다. 관측값이 지수 분포를 할 때 누적합 검정과 축차확률비 검정의 효율을 예를 들어 비교해 보았다.

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