• Title/Summary/Keyword: Noise Immunity

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Analysis of Several Digital Network Technologies for Hard Real-time Communications in Nuclear Plant

  • Song, Ki-Sang;No, Hee-Cheon;Kim, Dong-Hun;Koo, In-Soo
    • Nuclear Engineering and Technology
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    • v.31 no.2
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    • pp.226-235
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    • 1999
  • Applying digital network technology for advanced nuclear plant requires deterministic communication for tight safety requirements, timely and reliable data delivery for operation-critical and mission-critical characteristics of nuclear plant. Communication protocols, such as IEEE 802/4 Token Bus, IEEE 802/5 Token Ring, FDDI, and ARCnet, which have deterministic communication capability are partially applied to several nuclear power plants. Although digital communication technologies have many advantages, it is necessary to consider the noise immunity from electromagnetic interference (EMI), electrical interference, impulse noise, and heat noise before selecting specific digital network technology for nuclear plant. In this paper, we consider the token frame loss and data frame loss rate due to the link error event, frame size, and link data rate in different protocols, and evaluate the possibility of failure to meet the hard real-time requirement in nuclear plant.

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Blind Algorithms using a Random-Symbol Set under Biased Impulsive Noise (바이어스 된 충격성 잡음 하에서 랜덤 심볼 열을 이용한 블라인드 알고리듬)

  • Kim, Namyong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.1951-1956
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    • 2013
  • Distribution-matching type algorithms based on a set of symbols generated in random order provide a limited performance under biased impulsive noise since the performance criterion for the algorithms has no variables for biased signal. For the immunity against biased impulsive noise, we propose, in this paper, a modified performance criterion and derived related blind algorithms based on augmented filter structures and the distribution-matching method using a set of random symbols. From the simulation results, the proposed algorithm based on the proposed criterion yielded superior convergence performance undisturbed by the strong biased impulsive noise.

A Pacemaker AutoSense Algorithm with Dual Thresholds

  • Kim, Jung-Kuk;Huh, Woong
    • Journal of Biomedical Engineering Research
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    • v.23 no.6
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    • pp.477-484
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    • 2002
  • A pacemaker autosense algorithm with dual thresholds. one for noise or tachyarrhythmia detection (noise threshold, NT) and the other for intrinsic beat detection (sensing threshold. ST), was developed to improve the sensing performance in single pass VDD electrograms. unipolar electrograms, or atrial fibrillation detection. When a deflection in an electrogram exceeds the NT (defined as 50% of 57), the autosense algorithm with dual thresholds checks if the deflection also exceeds the ST. If it does, the autosense algorithm calculates the signal to noise ratio (SNR) of the deflection to the highest deflection detected by NT but lower than ST during the last cardiac cycle. If the SNR 2, the autosense algorithm declares an intrinsic beat detection and calculates the next ST based on the three most recent intrinsic peaks. If the SNR $\geq$2, the autosense algorithm checks the number of deflections detected by NT during the last cardiac cycle in order to determine if it is a noise detection or tachyarrhythmia detection. Usually the autosense algorithm tries to set the 57 at 37.5% of the average of the three intrinsic beats, although it changes the percentage according to event classifications. The autosense algorithm was tested through computer simulation of atrial electrograms from 5 patients obtained during EP study, to simulate a worst sensing situation. The result showed that the ST levels for autosense algorithm tracked the electrogram amplitudes properly, providing more noise immunity whenever necessary. Also, the autosense algorithm with dual thresholds achieved sensing performance as good as the conventional fixed sensitivity method that was optimized retrospectively.

Effect of Artificial Noise from Offshore Wind Power Generation on Immunological Parameters in Rock Bream (Oplegnathus fasciatus) (돌돔(Oplegnathus fasciatus)에 대한 인위적인 해상풍력발전소 건설소음의 면역학적 영향)

  • Choi, Kwang-Min;Joo, Min-Soo;Kang, Gyoungsik;Woo, Won-Sik;Kim, Kyung Ho;Son, Min-Young;Jeong, Son Ha;Park, Chan-Il
    • Journal of fish pathology
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    • v.34 no.2
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    • pp.243-248
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    • 2021
  • Offshore wind power generation is an energy generation field that is rapidly developing owing to the increasing demand for clean energy. However, the physiological response of fish to the underwater noise generated during construction or operation of wind turbines is unclear. We confirmed the effects of sound pressures of 125, 135, 145, and 155 dB/µPa, including 140 dB/µPa (the standard sound pressure for noise damage recognition in South Korea), through serum analysis in rock bream (Oplegnathus fasciatus). High mortality induced by reduced immunity through artificial infection after stimulation was confirmed. These results suggest that rock bream is negatively affected by the noise generated during the construction of offshore wind power plants.

Fiber optical system application for power plant measuring and control (발전소 계측제어 분야에 광시스템 적용)

  • 신건학;이원빈;조홍근;오상훈
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.683-687
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    • 1988
  • Digitalization of processor and increase of control information need the fiber optic data network which has excellent noise immunity and high-quality, widebaudwidth information transfer capability. It is aimed to offer a fiber optic dataway system for measuring and control the power plant, that has high reliability, high data transmission rate and small cable duct with large transmission capacity.

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Position control of robot's rotational axis having parallel link mechanism (평형링크 메카니즘이 있는 관절형 로보트 회전축의 위치제어)

  • 여인택;이연정
    • 제어로봇시스템학회:학술대회논문집
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    • 1986.10a
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    • pp.341-345
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    • 1986
  • In the course of robot control system building, there are problems in the position control loop of 3rd axis of robot manipulator. The problems are summerized as two: one is uncontrollability of position and the other is oscillation. And these problems are analyzed through experiment, and it is known that the cause of problems in torsional vibration of 3rd axis. So that these two problems are solved by noise immunity enhancement and lowering of PI controller gain.

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A Study of Mark Recognition with Noise Immunity (노이즈에 강인한 마크인식에 관한 연구)

  • Yang, Nam-Yeol;Jeong, Soo-Hoa
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3012-3014
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    • 1999
  • CCD 카메라를 이용한 화상처리가 최근 많은 분야에서 활용되고 있다. 특히 반도체 장비, 정밀 위치결정 시스템, 그리고 정밀 Alignment시스템과 같이 정밀한 제어가 요구되는 시스템에서 정화한 화상처리 기술이 요구되고 있다. 본 논문은 화상처리를 이용한 마크 인식에 관한 방법으로 CCD카메라로 부터 얻은 영상에 노이즈가 상당히 포함되어 있는 경우와 마크의 일부분만 보이는 경우에 마크를 정화히 찾는 방법에 관한 연구이다.

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Wide Voltage Input Receiver with Hysteresis Characteristic to Reduce Input Signal Noise Effect

  • Biswas, Arnab Kumar
    • ETRI Journal
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    • v.35 no.5
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    • pp.797-807
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    • 2013
  • In this paper, an input receiver with a hysteresis characteristic that can work at voltage levels between 0.9 V and 5 V is proposed. The input receiver can be used as a wide voltage range Schmitt trigger also. At the same time, reliable circuit operation is ensured. According to the research findings, this is the first time a wide voltage range Schmitt trigger is being reported. The proposed circuit is compared with previously reported input receivers, and it is shown that the circuit has better noise immunity. The proposed input receiver ends the need for a separate Schmitt trigger and input buffer. The frequency of operation is also higher than that of the previously reported receiver. The circuit is simulated using HSPICE at 0.35-${\mu}m$ standard thin oxide technology. Monte Carlo analysis is conducted at different process conditions, showing that the proposed circuit works well for different process conditions at different voltage levels of operation. A noise impulse of ($V_{CC}/2$) magnitude is added to the input voltage to show that the receiver receives the correct logic level even in the presence of noise. Here, $V_{CC}$ is the fixed voltage supply of 3.3 V.

Decision Feedback Equalizer based on Maximization of Zero-Error Probability (영확률 최대화에 근거한 결정궤환 등화)

  • Kim, Nam-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.8C
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    • pp.516-521
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    • 2011
  • In this paper, a nonlinear algorithm that maximizes zero-error probability (MZEP) with decision feedback (DF) is proposed to counteract both of severely distorted multi-path fading effect and impulsive noise. The proposed MZEP-DF algorithm has shown the immunity to impulsive noise and the ability of the feedback filter section to cancel the remaining intersymbol interference as well. Compared with the linear MZEP algorithm, it yields above 10 dB enhancement of steady state MSE performance in severely distorted multipath fading channels with impulse noise where the least mean square (LMS) algorithm does not converge below -3dB of MSE.

Matrix Pencil Method Using Fourth-order Statistic (4차 통계량을 이용한 Matrix Pencil Method)

  • Jang Woo-Jin;Wang Yi-Su;Zhou Wei-Wei;Koh Jin-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.6C
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    • pp.629-636
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    • 2006
  • In array signal processing, high order statistics can be used to estimate parameters from signal of sums of complex exponential. In this paper, we derive two types of direction finding algorithms which use the fourth-order cumulant and moment of the received array data. Since the fourth order cumulant can suppress the Gaussian noise, the response of MPM has better noise immunity than the conventional approaches. The performance of each method in regard to the probability of resolution and SNR in the presence of the Gaussian noise is investigated. As a result, the proposed method applied to the fourth-order statistic can find DOA more correctly in the presence of the Gaussian noise.