• Title/Summary/Keyword: On-line estimation

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On-line Friction Estimation and Compensation with a Reduced Model (축소 모델을 이용한 마찰력의 온라인 추정 및 보상 기법)

  • Choi, Jae-Il;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.178-181
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    • 1995
  • In this paper, on-line adaptive friction compensation scheme for the precise position control is presented. 2 DOF system with compliance and friction is used for the plant model. In order to reduce the calculation time for the parameter estimation, 1 DOF estimation model is used. The computer simulation and experimental results show the validity of the supposed scheme.

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A Study on the Life-Time Estimation of ACSR Transmission Line Due to a Flame (화염으로 인한 ACSR 송전선의 수명예측에 관한 연구)

  • Kim, Young-Dal
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.8
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    • pp.77-84
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    • 2005
  • The considerations for reminder life of transmission line is gradually higher. It is requisite for investigation of ACSR life to test tensile load of ACSR as a fundamental data. It is vary important to analysis correlations between results of tensile load testing and elapsed years. Estimation of ACSR life can be obtained by statistics processing using mechanical experimental results. It is a general method to use regression analysis as a statistics processing technique. In this paper, we did experiment on tensile strength of ACSR by using a new and due to flame for artificial fire, and gathering due to a flame. The limit of life estimation is decided by basic line using twenty percentage reduction of rate tensile strength. This basic line is like to results of Canada Ontario Hydro-research. There are $480[mm^2]$ ACSR which are experimented on this study.

On-line Measurement of Buffer Capacity of a Fermentation medium and Estimation of Organic Aicd Production (발효배지의 완충용량의 온라인 측정 및 유기산 생산 추정)

  • Hur, Won;Jung, Yoon-Keun
    • KSBB Journal
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    • v.13 no.4
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    • pp.461-467
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    • 1998
  • A fermentation system was supplemented with a device for the measurement of the durations of alkali pump feeding for automatic pH control and an A/D convertor for precise monitoring of pH value by computer. A software program was developed to measure buffer capacities from the pH signal and the pH control signal during fermentation. By measuring the buffer capacity on-line, levels of acetic acid were estimated by a software sensor using pH signal in a fermentation process of E.coli growing in a minimal medium. The measured values of acetic acid showed correlation to those of estimated by the software sensor. Lacitic acid production was also successfully estimated by the values of buffer capacities measured on-line.

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Robust On-line Rotor Time Constant Estimation for Induction Machines

  • Yoo, Anno
    • Journal of Power Electronics
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    • v.14 no.5
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    • pp.1000-1007
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    • 2014
  • This paper proposes an on-line rotor time constant estimation strategy for indirect field oriented induction machines. The performance of the indirect field oriented control is dependent especially on the rotor time constant whose value varies according to the temperature. The proposed method calculates the difference between the nominal rotor time constant and the real value from the d- and q-axis integration terms of a proportional integral (PI) current regulator and the demanded voltages of the induction machine to regulate the current in the steady state. Because the proposed strategy has a simple structure and is available in wide speed and torque ranges, the proposed method can be easily used in the industrial field. The effectiveness of proposed strategy is verified with simulations and a 7.5kW experimental setup.

Correction of Signboard Distortion by Vertical Stroke Estimation

  • Lim, Jun Sik;Na, In Seop;Kim, Soo Hyung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.7 no.9
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    • pp.2312-2325
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    • 2013
  • In this paper, we propose a preprocessing method that it is to correct the distortion of text area in Korean signboard images as a preprocessing step to improve character recognition. Distorted perspective in recognizing of Korean signboard text may cause of the low recognition rate. The proposed method consists of four main steps and eight sub-steps: main step consists of potential vertical components detection, vertical components detection, text-boundary estimation and distortion correction. First, potential vertical line components detection consists of four steps, including edge detection for each connected component, pixel distance normalization in the edge, dominant-point detection in the edge and removal of horizontal components. Second, vertical line components detection is composed of removal of diagonal components and extraction of vertical line components. Third, the outline estimation step is composed of the left and right boundary line detection. Finally, distortion of the text image is corrected by bilinear transformation based on the estimated outline. We compared the changes in recognition rates of OCR before and after applying the proposed algorithm. The recognition rate of the distortion corrected signboard images is 29.63% and 21.9% higher at the character and the text unit than those of the original images.

Estimation of Fault Location on a Power Line using the Time-Frequency Domain Reflectometry (절연전선 결함 위치 추정에 대한 시간-주파수 영역 반사파 계측법의 적용)

  • Doo, Seung-Ho;Kwak, Ki-Seok;Park, Jin-Bae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.2
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    • pp.268-275
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    • 2008
  • In this paper, we introduce a new method for detecting and estimating faults on a power line using the time-frequency domain reflectometry system. The system rests upon time-frequency signal analysis and uses a chirp signal which is multiplied by Gaussian envelope. The chirp signal is used as a reference signal, and we can get the reflected signal from a fault on a wire. To detect and estimate faults, we analyze the reflected signal by Wigner time-frequency distribution function and normalized time-frequency cross correlation function. In this paper we design an optimal reference signal for power line and implement a system for estimating fault distance on a power line with the TFDR implemented by PXI equipments. This approach is verified by some experiments with HIV 2.25mm power lines.

Lane Detection-based Camera Pose Estimation (차선검출 기반 카메라 포즈 추정)

  • Jung, Ho Gi;Suhr, Jae Kyu
    • Transactions of the Korean Society of Automotive Engineers
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    • v.23 no.5
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    • pp.463-470
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    • 2015
  • When a camera installed on a vehicle is used, estimation of the camera pose including tilt, roll, and pan angle with respect to the world coordinate system is important to associate camera coordinates with world coordinates. Previous approaches using huge calibration patterns have the disadvantage that the calibration patterns are costly to make and install. And, previous approaches exploiting multiple vanishing points detected in a single image are not suitable for automotive applications as a scene where multiple vanishing points can be captured by a front camera is hard to find in our daily environment. This paper proposes a camera pose estimation method. It collects multiple images of lane markings while changing the horizontal angle with respect to the markings. One vanishing point, the cross point of the left and right lane marking, is detected in each image, and vanishing line is estimated based on the detected vanishing points. Finally, camera pose is estimated from the vanishing line. The proposed method is based on the fact that planar motion does not change the vanishing line of the plane and the normal vector of the plane can be estimated by the vanishing line. Experiments with large and small tilt and roll angle show that the proposed method outputs accurate estimation results respectively. It is verified by checking the lane markings are up right in the bird's eye view image when the pan angle is compensated.

Emission Estimation of Air Pollutants in Kimhae Area (김해시 대기오염물질 배출량 산정)

  • 박종길;김종필;김지형
    • Journal of Environmental Science International
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    • v.7 no.5
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    • pp.647-652
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    • 1998
  • This study is to find out the emission estimation in Kimhae area. For this purpose, the Kimhae statistical yearbook and data of waste facilities issued by Kimhae city and the report on energy census issued by the ministry of trade, industry and energy are used. Each item for the emission estimation is $SO_2$, CO, HC, Nox, TSP from point, line, area sources. The results were as follows; The air pollutants with the highest mont of emission from the emission sources is CO followed by Nox, $SO_2$, TSP, HC in descending order of magnitude. The emission consists of 66.15% of line, 24.65% of area and 9.20% of point sources at Kimhae.

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A Study on the Capacity Analysis for improving Railway Systems (철도시스템 개선을 위한 용량분석에 관한 연구)

  • Kim Dong-Hee;Kim Seong-Ho
    • Proceedings of the KSR Conference
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    • 2003.05a
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    • pp.272-279
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    • 2003
  • There are two methodologies to increase transport capacity of railway. One is to invest railroad equipment or vehicles, and the other is to improve operation efficiency through optimization. All of these is intended to increase transport capacity by improving the line capacity, So far, we treat the line capacity as the criteria for evaluating investment alternatives or for restricting train frequencies, and this criteria is calculated statical and experimental numerical formula. But, line capacity has special attribute that changes dynamically according to operational conditions, so there is a need of new line capacity estimation system. Korea Railroad Research Institute(KRRI) proposed a new line capacity estimation system based on the probability simulation method. In this research. we perform analysis of line capacity for the railway improvement alternatives, and to represent the results.

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On-Line Aircraft Parameter Identification Using Fourier Transform Regression With an Application to NASA F/A-18 Harv Flight Data

  • Song, Yongkyu;Song, Byungheum;Seanor, Brad;Napolitano, Marcello R.
    • Journal of Mechanical Science and Technology
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    • v.16 no.3
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    • pp.327-337
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    • 2002
  • This paper applies a recently developed on-line parameter identification (PID) technique to sets of real flight data and compares the results with those of a state-of-the-art off-line PID technique. The on-line PID technique takes Linear Regression from Fourier Transformed equations and the off-line PID is based on the traditional Maximum Likelihood method. Sets of flight data from the NASA F/A-18 High Alpha research Vehicle (HARV) circraft, which has been recorded from specifically designed maneuvers and used for our line parameter estimation, are used for this study. The emphasis is given on the accuracy and on-line measure of reliability of the estimates. The comparison is performed for both longitudinal and lateral-directional dynamics for maneuvers at angles of attack ranging u=20°through $\alpha$=40°. Results of the two estimation processes are also compared with baseline wind tunnel estimates whenever possible.