• Title/Summary/Keyword: signal normalizing method

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The development of solar tracking sensor and controller for improvement of generation efficiency (발전 효율향상을 위한 태양광추적 센서 및 제어기 개발)

  • Han, Ki-Bong;Han, Tae-Hee;Lee, Shin-Won;Han, Seung-Woo
    • Journal of the Korean Solar Energy Society
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    • v.32 no.6
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    • pp.29-36
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    • 2012
  • The existing solar tracking sensor for 2 axial control system to trace latitude and longitude is made of four phototransistor. The phototransistor-making is difficult and it's manufacturing is more high-priced than a wide use phototransistor because they have to the same characteristics of each phototransistor output signal. This paper described the algorithm for supplement these weakness. The algorithm applied to signal normalizing method and vector decomposition law. The deviations of each a wide use phototransistor output signal are resolved by signal normalizing method and it is able to make a solar tracking sensor using three phototransistor by vector decomposition law. Therefore, in this paper, it is reduced the number of phototransistor that is composed of solar tracking sensor and possible to use a wide use phototransistor by the proposed algorithm.

Normalization Diagnosis of Aging Process on Partial Discharge Signals of CV Cable (CV케이블의 부분방전 신호를 통한 열화과정의 정량적 진단)

  • 소순열;임장섭;김진사;이준웅;김태성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.451-455
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    • 1997
  • The partial discharge has been blown as the chief breakdown of power equipments. The analysis and the recognition is much difficult because the partial discharge signal is very small and has complex aging pattern. Recently, insulation aging diagnosis based on pattern of phase(Ф), partial discharge magnitude(q), number(n) has been very important. Owing to depreciate the reappearance of aging progress at the electrical tree pattern and to be difficult to analyze visually, the study on partial discharge pattern is suggested to normalizing analysis method of partial discharge signals. This parer is purposed on prediction of life-time measurement of cv-cable, on decision of risk degree with normalization and real-time measurement of partial discharge signals for aging diagnosis of cv-cable. As normalizing the aging signals of electrical tree in cv-cable, it is able to confirm risk degree of insulation material with the distribution of Ф-q-n and recognize the process of aging pattern using neural network.

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AC Arc Detection Method using Mixed Filter and Frequency Analysis (혼합필터와 주파수분석기법을 이용한 교류 아크 검출 기법)

  • Jang, Dong-Uk;Park, Seong-Hee;Lee, Kang-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.4
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    • pp.200-205
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    • 2017
  • In this paper, we propose a technique to determine the normal and arc of an alternating current using a mixed filter composed of an average filter and a band-pass filter and a frequency analysis. The proposed method uses the moving average filter of the FIR filter structure for noise removal and the band-pass filter of the IIR filter structure for detecting only specific frequency components after normalizing the measured current signal based on the maximum value. After performing Fast Fourier Transform (FFT) using the band-pass filtered signal, the total energy is calculated using the magnitude component of the frequency, and the arc is detected using the magnitude of the calculated energy. In order to show the validity of the proposed method, we experimented with various data and found that arc and steady state can be easily discriminated by calculating spectral energy. Therefore, it is considered that the proposed method can be applied to arc diagnosis of low voltage electric wire.

Image Signal Denoising by the Soft-Threshold Technique Using Coefficient Normalization in Multiwavelet Transform Domain (멀티웨이블릿 변환영역에서 계수정규화를 이용한 Soft-Threshold 기법의 영상신호 잡음제거)

  • Kim, Jae-Hwan;Woo, Chang-Yong;Park, Nam-Chun
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.4
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    • pp.255-265
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    • 2007
  • In case of wavelet coefficients have correlation, in image signal denoising using wavelet shrinkage denoising method, the denoising effect for the image signal is reduced when the wavelet shrinkage denoising method is used. The coefficients of multiwavelet transform have correlation by pre-filters. To solve the degradation problem in multiwavelet transform, V Sterela suggested a new pre-filter for the Universal threshold or weighting factors to the threshold. In this paper, to improve the denoising effect in the multiwavelet transform, the coefficient normalizing method that the coefficient are divided by estimated noise deviation is adopted to the transformed multiwavelet coefficients in the course of wavelet shrinkage technique. And the thresholds of universal, SURE and GCV are estimated using normalized coefficients and tried to denoise by the wavelet shrinkage technique. We compared PSNRs of denoised images for each thresholds and confirmed the efficiency of the proposed method.

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A Study on the Robustness of a Direct Adaptive Pole-placement Controller (직접 적응 극배치 제어기의 강인성에 관한 연구)

  • Kim, Young-Jin;Kim, Eung-Seok;Yang, Hai-Won
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.666-669
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    • 1991
  • This paper deals with the robustness of a direct adaptive pole-placement control algorithm for continuous time plants with unmodeled dynamics. In this paper, least squares method is used for controller parameter adaptation and covariance matrix update equation is modified by normalizing signal to guarantee the boundedness of all signals in the closed loop system. In the proposed algorithm, no a priori knowledge is required and it is shown that persistence of excitation condition is required to ensure the stability of the closed loop system.

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Analysis of Global Oscillation via Sync Search in Power Systems (전력계통에서 동조탐색과 광역진동해석)

  • Shim, Kwan-Shik;Nam, Hae-Kon;Kim, Yong-Gu;Moon, Young-Hoan;Kim, Sang-Tae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1255-1262
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    • 2009
  • The present study explained the phenomenon that low frequency oscillation is synchronized with discrete data obtained from a wide area system, and a sync search method. When a disturbance occurs in an power system, various controllers operate in order to maintain synchronization. If the system's damping is poor, low frequency oscillations continue for a long time and the oscillations are synchronized with one another at specific frequency. The present study estimated dominant modes, magnitude and phase of signals by applying parameter estimation methods to discrete signals obtained from an power system, and performed sync search among wide area signals by comparing the estimated data. Sync search was performed by selecting those with the same frequency and damping constant from dominant oscillation modes included in a large number of signals, and comparing their magnitude and phase. In addition, we defined sync indexes in order to indicate the degree of sync between areas in a wide area system. Furthermore, we proposed a wide area sync search method by normalizing mode magnitude in discrete data obtained from critical generator of the wide area. By applying the sync search method and sync indexes proposed in this study to two area systems, we demonstrated that sync scanning can be performed for discrete signals obtained from power systems.

An Implementation Method of Frequency Offset Synchronization Using Compact CORDIC for OFDM Systems (OFDM 시스템에서 Compact CORDIC을 이용한 주파수 오프셋 동기화 구현 기법)

  • Lee Kyu-In;Yu Sung-Wook;Kim Jong-Han;Lee Jae-Kon;Cho Yong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.7C
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    • pp.706-712
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    • 2006
  • In this letter, we propose a compact CORDIC processor for implementation of carrier frequency synchronization block in an OFDM (Orthogonal Frequency Division Multiplexing) system. The compact CORDIC processor is proposed by using inherenct properties of an OFDM system for estimation and compensation of carrier frequency offset, and is composed of a compact CORDIC preprocessor and a compact CORDIC processor. The compact CORDIC preprocessor plays a role of normalizing input signal efficiently, and the compact CORDIC processor is proposed to perform the vectoring mode and rotational mode jointly in CORDIC operation for carrier frequency synchronization. It is shown by FPGA implementation that the proposed compact CORDIC processor can achieve better performance with a significantly reduced hardware complexity than the conventional CORDIC approach.

Quantization Method for Normalization of JPEG Pleno Hologram (JPEG Pleno 홀로그램 데이터의 정규화를 위한 양자화)

  • Kim, Kyung-Jin;Kim, Jin-Kyum;Oh, Kwan-Jung;Kim, Jin-Woong;Kim, Dong-Wook;Seo, Young-Ho
    • Journal of Broadcast Engineering
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    • v.25 no.4
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    • pp.587-597
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    • 2020
  • In this paper, we analyze the normalization that occurs when processing digital hologram and propose an optimized quantization method. In JPEG Pleno, which standardizes the compression of holograms, full complex holograms are defined as complex numbers with 32-bit or 64-bit precision, and the range of values varies greatly depending on the method of hologram generation and object type. Such data with high precision and wide dynamic range are converted to fixed-point or integer numbers with lower precision for signal processing and compression. In addition, in order to reconstruct the hologram to the SLM (spatial light modulator), it is approximated with a precision of a value that can be expressed by the pixels of the SLM. This process can be refereed as a normalization process using quantization. In this paper, we introduce a method for normalizing high precision and wide range hologram using quantization technique and propose an optimized method.

Detection Method of Vehicle Fuel-cut Driving with Deep-learning Technique (딥러닝 기법을 이용한 차량 연료차단 주행의 감지법)

  • Ko, Kwang-Ho
    • Journal of the Korea Convergence Society
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    • v.10 no.11
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    • pp.327-333
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    • 2019
  • The Fuel-cut driving is started when the acceleration pedal released with transmission gear engaged. Fuel economy of the vehicle improves by active fuel-cut driving. A deep-learning technique is proposed to predict fuel-cut driving with vehicle speed, acceleration and road gradient data in the study. It's 3~10 of hidden layers and 10~20 of variables and is applied to the 9600 data obtained in the test driving of a vehicle in the road of 12km. Its accuracy is about 84.5% with 10 variables, 7 hidden layers and Relu as activation function. Its error is regarded from the fact that the change rate of input data is higher than the rate of fuel consumption data. Therefore the accuracy can be better by the normalizing process of input data. It's unnecessary to get the signal of vehicle injector or OBD, and a deep-learning technique applied to the data to be got easily, like GPS. It can contribute to eco-drive for the computing time small.