• 제목/요약/키워드: operating characteristic

검색결과 1,733건 처리시간 0.035초

주의력의 신경심리학 (Neuropsychology of Attention)

  • 김창윤;김성윤
    • 수면정신생리
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    • 제6권1호
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    • pp.26-31
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    • 1999
  • "Attention" is not defined sufficiently. This term incorporates several dimensions or complex information processes such as alertness, spatial distribution, focused attention, sustained attention, divided attention and supervisory attentional control. In practice, however, various aspects of attention cannot be assessed separately with a single test. Moreover, a particular test is never assessing attention only, because the several intervening variables may influence the attentional component. Therefore, one can only assess a certain aspect of human behavior with special interest for its attentional component. This paper attempted to clarify various concepts of attention, reviewed signal detection theories with receiver operating characteristic(ROC) curves, and listed practical methods for assessment of attention.

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Designing Statistical Test for Mean of Random Profiles

  • Bahri, Mehrab;Hadi-Vencheh, Abdollah
    • Industrial Engineering and Management Systems
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    • 제15권4호
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    • pp.432-445
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    • 2016
  • A random profile is the result of a process, the output of which is a function instead of a scalar or vector quantity. In the nature of these objects, two main dimensions of "functionality" and "randomness" can be recognized. Valuable researches have been conducted to present control charts for monitoring such processes in which a regression approach has been applied by focusing on "randomness" of profiles. Performing other statistical techniques such as hypothesis testing for different parameters, comparing parameters of two populations, ANOVA, DOE, etc. has been postponed thus far, because the "functional" nature of profiles is ignored. In this paper, first, some needed theorems are proven with an applied approach, so that be understandable for an engineer which is unfamiliar with advanced mathematical analysis. Then, as an application of that, a statistical test is designed for mean of continuous random profiles. Finally, using experimental operating characteristic curves obtained in computer simulation, it is demonstrated that the presented tests are properly able to recognize deviations in the null hypothesis.

엔진제어를 위한 수학적 모델의 컴퓨터 해석 (Computer Analysis of Mathematical Model for Engine Control)

  • 김유남;우광방
    • 대한전기학회논문지
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    • 제38권9호
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    • pp.724-732
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    • 1989
  • The structure of engine and its interaction are investigated and the construction of mathematical model for the performance evaluation is presented and then simulated. The total system is classified as air-fuel inlet element, intake manifold, combustion, and engine dynamics and their control function are schematically evaluated. Because of the model structure with general engine function and computer simulation of the chosen engine, physical characteristics of the corresponding engine and the engine data of normal operation state are used. According to the study, it is possible to predict the mixture rate by by the difference in the mass of fuel and air into cylinder and to evaluate and trace dynamic characteristic of operation state under various operating condition. The model characteristic under the transient operating condition makes it possible to effectively evaluate the operation of actual engine through the result of simulation.

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마이크로터빈과 연료전지의 EMTP-RV 모델링을 통한 마이크로그리드 내 동특성 분석 (Dynamic analysis of Microturbine and FuelCell in MicroGrid using EMTP-RV)

  • 서규석;주재현
    • 조명전기설비학회논문지
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    • 제24권10호
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    • pp.42-48
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    • 2010
  • The Microsource has to supply high quality Power that has high reliability and high energy efficiency to Load according to operating type of Microgrid. The energy sources of microsource type have various dynamic characteristic and transient response corresponding to classes and application skill. This paper shows dynamic characteristic of Microgrid according to Energy Source of microsource type. This research has been carried out by detailed modelling of Microturbine system and Fuelcell system. All models are realized by EMTP/RV and simulated change of operating type and load increase within Microgrid of DC constant voltage inverter model and Microturbine, Fuelcell based Microsource.

BLDC 전동기 운전 특성을 이용한 새로운 고장 검출 기법 구현 (Fault Detection of BLDC Motor Based on Operating Characteristic)

  • 이정대;박병건;김태성;류지수;현동석
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2007년도 하계학술대회 논문집
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    • pp.325-327
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    • 2007
  • This paper proposes a novel sensorless fault detection algorithm for a brushless DC(BLDC) motor drive system. This proposed method is configured without the additional sensor for fault detection and identification. The fault detection and identification are achieved by a simple algorithm using the operating characteristic of the BLDC motor. This proposed method can also be embedded into existing BLDC motor drive systems as a subroutine without excessive computational effort. The feasibility of a novel sensorless fault detection algorithm is validated in simulation.

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다단계 스?로트 샘플링검사 계획 (Multi-level skip-lot sampling plan)

  • 최병철
    • 응용통계연구
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    • 제6권2호
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    • pp.277-287
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    • 1993
  • 본 논문은, 품질이 좋은 제품일수록 검사비용을 줄여서 생산성을 높일 수 있도록, 1단계와 2 단계 스 로트 샘플링검사 계획을 n단계 스 로트 샘플링 검사 계획으로 일반화한 것이다. 이 다단계 스 로트 샘플링검사 계획에서는 매 검사단계마다 연속적으로 합격되어야 할 로 트의 수뿐만 아니라 구분의 크기까지를 자유롭게 택할 수 있게 되어있다. 또한 검사특성곡 선의 일반 형태를 도출하였고, 이를 이용하여 2단계 및 3단계 스 로트 샘플링검사 계획을 비교하였다.스 로트 샘플링검사 계획을 비교하였다. 비교하였다.

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Positive and negative predictive values by the TOC curve

  • Hong, Chong Sun;Choi, So Yeon
    • Communications for Statistical Applications and Methods
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    • 제27권2호
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    • pp.211-224
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    • 2020
  • Sensitivity and specificity are popular measures described by the receiver operating characteristic (ROC) curve. There are also two other measures such as the positive predictive value (PPV) and negative predictive value (NPV); however, the PPV and NPV cannot be represented by the ROC curve. Based on the total operating characteristic (TOC) curve suggested by Pontius and Si (International Journal of Geographical Information Science, 97, 570-583, 2014), explanatory methods are proposed to geometrically describe the PPV and NPV by the TOC curve. It is found that the PPV can be regarded as the slope of the right-angled triangle connecting the origin to a certain point on the TOC curve, while 1 - NPV can be represented as the slope of the right-angled triangle connecting a certain point to the top right corner of the TOC curve. When the neutral zone exists, the PPV and 1-NPV can be described as the slopes of two other right-angled triangles of the TOC curve. Therefore, both the PPV and NPV can be estimated using the TOC curve, whether or not the neutral zone is present.

건설기계용 유압실린더 위치 제어시스템의 성능개선에 관한 연구 (A study on performance improvement of position control system in hydraulic cylinder for heavy construction machinery)

  • 한석재;박성환;이진걸
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1450-1454
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    • 1996
  • Even though digital control type high speed solenoid valve is a little inferior to analog control type servo valve and proportional control valve in performance, it is cheap and has secure performance against pollutant and simple control circuit. But high speed solenoid valve is hardly used for heavy machinery instead of servo valve or proportional control valve that is used in severe condition because the valve itself is small capacity and it shows wide dead zone during on-off control and chattering of hydraulic cylinder by chattering of pressure. It is desirable to use low-priced and strong pollutant resistant high speed solenoid valve for obtaining reliability of operation from severe working condition because it isn't necessary to acquire response characteristic of high frequency when we consider the characteristic of heavy machinery operation. In this study, PWM control algorithm for pilot pressure control of large capacity pilot operating valve will be used for precision position control of heavy machinery hydraulic cylinder. Not only cost reduction of main control valve but also high reliability of heavy machinery in severe condition can be obtained by using this pilot operating spool valve with high speed solenoid valve.

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생존 분석 자료에서 적용되는 시간 가변 ROC 분석에 대한 리뷰 (Review for time-dependent ROC analysis under diverse survival models)

  • 김양진
    • 응용통계연구
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    • 제35권1호
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    • pp.35-47
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    • 2022
  • Receiver operating characteristic (ROC) 곡선은 이항 반응 자료에 대한 마커의 분류 예측력을 측정하기 위해 널리 적용되어왔으며 최근에는 생존 분석에서도 매우 중요한 역할을 하고 있다. 여러 가지 유형의 중도 절단과 원인 불명 등 다양한 종류의 결측 자료를 포함한 생존 자료 분석에서 마커의 사건 발생 여부에 대한 예측력을 판단하기 위해 기존의 통계량을 확장하였다. 생존 분석 자료는 각 시점에서의 사건 발생 여부로 이해할 수 있으며, 따라서 시점마다 ROC 곡선과 AUC를 구할 수 있다. 본 논문에서는 우중도 절단과 경쟁 위험 모형하에서 사용되는 다양한 방법론과 관련 R 패키지를 소개하고 각 방법의 특성을 설명하고 비교하였으며 이를 검토하기 위해 간단한 모의실험을 시행하였다. 또한, 프랑스에서 수집된 치매 자료의 마커 분석을 시행하였다.

시험 데이터를 지반으로 한 마이크로터빈 운전 시뮬레이션 (Operation Simulation of a Microturbine Based on Test Data)

  • 이종준;윤재은;김동섭
    • 한국유체기계학회 논문집
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    • 제9권6호
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    • pp.22-28
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    • 2006
  • Operation of a microturbine was simulated on the basis of component characteristic parameters obtained from performance test. Characteristic parameters, such as compressor and turbine efficiencies, recuperator effectiveness as well as turbine inlet temperature, were obtained for a wide operation range. Component characteristics including performance maps and characteristic curves were generated using measured data. Based on the component characteristics, a simulation program was constructed and operation of the microturbine was simulated, and the simulated results were compared with the measured data to verify the program. Also, influence of variation in the power control scheme on the operating characteristic and performance of the engine was simulated. The simulation program can be used for predicting operation of both healthy and degraded engine conditions.