• Title/Summary/Keyword: Measuring parameters

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Modeling and verification of generator/control system of Seo-Inchon combined-cycle plant by load rejection test (부하차단시험에 의한 서인천복합화력 발전기.제어계의 모델링 및 검증)

  • 최경선;문영환;김동준;추진부;류승헌;권태원
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.501-510
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    • 1996
  • The gas-turbine generator of Seo-Incheon combined-cycle plant was tested for derivation of a model for dynamic analysis. Load rejection and AVR step test was performed to get the dynamic response of generator. The parameters of generator/control system model were determined by these measured data. No-load saturation test was performed for the saturation characteristics of the generator under steady state. V-curve test was also performed so as to find exact generator parameters. Q-axis parameters of generator was derived by measuring power angle. AVR and governor constants have been tuned by their oscillatory period and setting time characteristics. The derived parameters of generator control system is verified by one-machine infinite bus system simulation. (author). 7 refs., 20 figs., 5 tabs.

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Q measurement of two port RE cavity by scattering parameters (산란행렬에 의한 2단자망 RF 공동공진기의 Q 측정)

  • 한대현
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.4 no.4
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    • pp.895-899
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    • 2000
  • A method of measuring Q of a two port cavity by scattering parameters is proposed. The scattering parameters of a two port cavity resonator are derived by a lumped equivalent circuit model as a function of cavity parameters, including the cavity Q. These can be also obtained by direct measurement with a modern network analyzer, The results show good agreement with those from other well-known methods. This two port measurement can provide additional information such as the coupled power ratio, which is one of the important parameters for the beam accelerating cavities.

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Computer Vision Based Measurement, Error Analysis and Calibration (컴퓨터 시각(視覺)에 의거한 측정기술(測定技術) 및 측정오차(測定誤差)의 분석(分析)과 보정(補正))

  • Hwang, H.;Lee, C.H.
    • Journal of Biosystems Engineering
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    • v.17 no.1
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    • pp.65-78
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    • 1992
  • When using a computer vision system for a measurement, the geometrically distorted input image usually restricts the site and size of the measuring window. A geometrically distorted image caused by the image sensing and processing hardware degrades the accuracy of the visual measurement and prohibits the arbitrary selection of the measuring scope. Therefore, an image calibration is inevitable to improve the measuring accuracy. A calibration process is usually done via four steps such as measurement, modeling, parameter estimation, and compensation. In this paper, the efficient error calibration technique of a geometrically distorted input image was developed using a neural network. After calibrating a unit pixel, the distorted image was compensated by training CMLAN(Cerebellar Model Linear Associator Network) without modeling the behavior of any system element. The input/output training pairs for the network was obtained by processing the image of the devised sampled pattern. The generalization property of the network successfully compensates the distortion errors of the untrained arbitrary pixel points on the image space. The error convergence of the trained network with respect to the network control parameters were also presented. The compensated image through the network was then post processed using a simple DDA(Digital Differential Analyzer) to avoid the pixel disconnectivity. The compensation effect was verified using known sized geometric primitives. A way to extract directly a real scaled geometric quantity of the object from the 8-directional chain coding was also devised and coded. Since the developed calibration algorithm does not require any knowledge of modeling system elements and estimating parameters, it can be applied simply to any image processing system. Furthermore, it efficiently enhances the measurement accuracy and allows the arbitrary sizing and locating of the measuring window. The applied and developed algorithms were coded as a menu driven way using MS-C language Ver. 6.0, PC VISION PLUS library functions, and VGA graphic functions.

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Analysis of Measuring Error for Particle Size Analysis by Laser Diffraction Spectrometer (입자크기분석을 위한 레이저회절 분광계의 측정오차 분석)

  • Ha, Sang-An;Son, Heui-Jeong
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.4
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    • pp.713-722
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    • 2000
  • This study analysed error of measurement and reproducibility for particle size analysis by the laser diffraction spectrometer. Laser diffraction spectrometers has become a very important method of particle size analysis. This measuring method has the advantage of simple operation, good reproducibility and rapid analysis. A feeding and dispersing system have been developed, which allows mass throughputs between 0.1~23 g/min in flowing air and 1.4~35% in flowing liquid. It has been used as a feeder unit for wet and dry particle size analysis from diffraction patterns. Relevant parameters, such as particle shape, particle size, dispersion, flow rate, concentration were analysed for measuring error. And system parameters of instruments for measurement of dynamic processes, eg, measuring time, focal plane, injection pressure drop and dispersion effect by the ultrasonic and mixing of preliminary treatment, were also discussed.

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Case Study on Measuring Technology Level Applying Growth Curve Model: Three Core Areas of Fishery Science and Technology (성장곡선 모형 적용을 통한 기술수준평가 사례 연구 : 특정 수산과학기술 분야를 중심으로)

  • Kim, Wan-Min;Park, Ju-Chan;Bark, Pyeng-Mu
    • The Journal of Fisheries Business Administration
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    • v.46 no.3
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    • pp.103-118
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    • 2015
  • The purpose of this paper is to discuss possibilities of applying growth curve models, such as Logistic, Log-Logistic, Log-Normal, Gompertz and Weibull, to three specific technology areas of Fishery Science and Technology in the process of measuring their technology level between Korea and countries with the state-of-the art level. Technology areas of hazard control of organism, environment restoration, and fish cluster detect were selected for this study. Expert panel survey was conducted to construct relevant panel data for years of 2013, 2016, and a future time of approaching the theoretical maximum technology level. The size of data was 70, 70 and 40 respectively. First finding is that estimation of shape and location parameters of each model was statistically significant, and lack-of-fit test using estimated parameters was statistically rejected for each model, meaning all models were good enough to apply for measuring technology levels. Second, three models other than Pearl and Gompertz seemed very appropriate to apply despite the fact that previous case studies have used only Gompertz and Pearl. This study suggests that Weibull model would be a very valid candidate for the purpose. Third, fish cluster detect technology level is relatively higher for both Korea and a country with the state-of-the-art among three areas as of 2013. However, all three areas seem to be approaching their limits(highest technology level point) until 2020 for countries with the state-of-the-art. This implies that Korea might have to speed up her research activities in order to catch up them prior to 2020. Final suggestion is that future study may better apply various and more appropriate models respectively considering each technology characteristics and other factors.

Analysis of loop impedance characteristic based on korea internal electrical environment (국내환경을 고려한 loop impedance 특성 분석)

  • Jung, Jin-Soo;Han, Woon-Ki;Kim, O-Huan;Ahn, Jae-Min;Lee, Seung-Jae
    • Proceedings of the KIEE Conference
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    • 2009.07a
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    • pp.2174_2175
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    • 2009
  • This Paper present about loop impedance characteristic based on korea internal electrical environment. Analysis parameters were touch voltage, electrical shock current and human body resistance. Result, For protect of electrical shock must measuring of loop impedance. And current capacity & loop impedance are must important parameters.

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Measurement of the Reverberation Time of Rooms with Reference to Other Acoustical Parameters (실내공간의 잔향시간과 음향변수 측정방법)

  • 오양기;주진수;정광용;김선우
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.392-396
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    • 2001
  • Revision of KS, Korean Standards, is currently actively discussed. It is just the time for a new world class standards under the new system with WTO, World Trade Organization. This paper is a part of “Researchs on the Standards in the Building Acoustic Field”, as one of KS revision projects. The aim of this study is to define the requirements for measuring the reverberation time and other major room acoustical parameters.

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The difference between two distribution functions

  • Hong, Chong Sun
    • Journal of the Korean Data and Information Science Society
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    • v.24 no.6
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    • pp.1449-1454
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    • 2013
  • There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

Comparison of Methods for Optimal Sensor Locations (최적 측정위치 선택 방법들의 비교 연구)

  • 강태우;권순정;신수봉
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.10a
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    • pp.253-260
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    • 2001
  • In a structural inverse problem with a limitation to the number of measuring degrees of freedom, the selection of optimal sensor locations (OSL) is critical for a good result. The current research proposes and a new OSL method and compares it with a widely used OSL method. The proposed method utilizes the sensitivity of eigenvectors with respect to the structural parameters. A simulation study for a tower structure is carried out. The structural parameters are estimated by a SI method. The influences of OSL on SI results are investigated.

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Measuring machine parameters of inverter-fed induction motors for an accurate torque control (고정밀 토크제어를 위한 인버터 구동 유도전동기의 상수 측정)

  • Lee Jin-Woo
    • Proceedings of the KIPE Conference
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    • 2002.11a
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    • pp.12-16
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    • 2002
  • This paper deals with the measurement of machine parameters of inverter-fed induction motors for an accurate torque control applications such as machine tools and tension control machines. After discussing nonlinearities of both inverter and motor, this paper suggests appropriate compensation and measurement methods. The experimental results show the validity of the proposed method in the operating conditions.

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