• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.233-239
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• 2004

현재 국내 인체 이식용 전자 의료기의 이식건수는 매년 약 1800 여건으로 해마다 증가하고 있으며 그 연령대도 다양한 작업환경에 노출되는 청장년층으로 급속히 확대되어 가고 있다. 이러한 이식용 의료기는 인공 심장 박동기, 이식형 제세동기, 진통억제를 위한 이식형 전기 펄스 발생기, 이식형 약물주입기 등을 포함한다. 그러한 기기들은 미세한 생체 신호에 따라 반응하기 때문에 생체 신호이외의 잡음에 의한 오동작은 절대적으로 피해져야 하며 경우에 따라 생명위협과도 직결된다. 본 논문에서는 현재사용 중인 이식형 전자의료기들의 구조와 동작원리, 다양한 작업 환경 하에서 잡음의 영향을 고찰하고, 잡음에 의한 오동작의 방지 방안을 고찰함으로써 전자의료기 인체 삽입자의 작업환경에 따른 안전문제를 제고하고자 한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.3
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• pp.221-228
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• 2000

본 논문에서는 전기·전자 장비의 활용이 확대되면서 더욱 더 관심이 고조되고 있는 전자파장해에 대하여 논하고자 한다. 기존 PWM 직류전원장치에서는 회로 소자 및 배치에 따른 기생소자와 갑작스런 전압/전류의 변화에 의해 전자파장해를 발생시킨다. 본 논문에서는 PWM 직류전원장치에서 발생하는 전자파장해의 특성을 고찰하고, 출력전압 조절에 큰 영향을 주지 않는 범위내에서 PWM 제어가 가능하면서 두 개의 고정된 스위칭주파수로 연속적으로 변조하는 Bi-FM 변조제어방식과 랜덤하게 변화하는 스위칭주파수 변조제어방식을 이용하여 전도잡음을 저감시킬 수 있는 변조방식을 논할 것이다. 또한 이들 변조 방식의 주파수 스펙트럼 특성을 비교·분석하여 설명하고, 제어기를 분석·설계하여 실험을 통하여 스위칭주파수와 그 고조파 주파수들의 측대역으로 전도잡음이 분산되고 전도잡음의 피크치가 감소됨을 확인하고자 한다.

• Journal of IKEEE
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• v.23 no.4
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• pp.1366-1372
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• 2019

In this paper, we designed a revised neural network to remove the Monte Carlo Rendering noise contained in the ray tracing graphics. The Monte Carlo Rendering is the best way to enhance the graphic's realism, but because of the need to calculate more than thousands of light effects per pixel, rendering processing time has increased rapidly, causing a major problem with real-time processing. To improve this problem, the number of light used in pixels is reduced, where rendering noise occurs and various studies have been conducted to eliminate this noise. In this paper, a deep learning is used to remove rendering noise, especially by separating the rendering image into diffuse and specular light, so that the structure of the dual neural network is designed. As a result, the dual neural network improved by an average of 0.58 db for 64 test images based on PSNR, and 99.22% less light compared to reference image, enabling real-time race-tracing rendering.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.134-140
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• 2003

In this paper, a hardware implementation of gas flow meter for accuracy improvement and saving repair costs at a field is investigated. An adaptive filter using LMS algorithms for estimating cavity vibration frequencies in noisy environments is also studied. The proposed cavity gas flow meter measures cavity sound signals in gas flow tube using microphone and signal processing systems estimate the cavity vibration frequency from the measured signal. The flow velocity and flow quantity can be calculated using the estimated cavity vibration frequency. Since cavity vibration frequency is corrupted by the environmental noise, an adaptive filter using NLMS algorithms is used for cancelling the environmental noise. Experiments using 1MS32OC32 digital signal processor are performed to show the effectiveness of the proposed system.

• Smart Media Journal
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• v.4 no.1
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• pp.33-38
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• 2015

In this paper, we propose the methods not only to eliminate ELF(Extremely Low Frequency) EMI(Electro-Magnetic Interference) noice for extending recognition distance, but also to utilize the the PLN for detecting starting instance of a hand gesture using electric potential sensor. First, we measure strength of electric field generated in the smart devices such as TV and phone, and minimize EMI through efficient arrangement of the sensors. Meanwhile, we utilize the 60 Hz PLN to extract the starting point of hand gesture. Thereafter, we eliminate the PLN generated in the smart device and circuit of sensors. And then, we shield the sensors from an electric noise generated from devices. Finally, through analyzing the frequency components according to the gesture of target, we use the low pass filter and the Kalman filter for elimination of remaining electric noise. We analyze and evaluate the proposed ELF-band EMI eliminating method for non-contact remote sensing of the EPS(Electric Potential Sensor). Combined with a detecting technique of gesture starting point, the recognition distance for gestures has been proven to be extended to more than 3m, which is critical for real application.

• Journal of IKEEE
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• v.26 no.4
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• pp.577-583
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• 2022

Verilog-HDL-based modeling can be performed to confirm the fast operation characteristics after setting the design parameters of each block considering the stability of the system by performing linear phase-domain modeling on the phase-locked loop. This paper proposed Verilog-HDL modeling including DCO noise and DTC nonlinear characteristic. After completing the modeling, the time-domain transient simulation can be performed to check the feasibility and the functionality of the proposed PLL system, then the phase noise result from the system design based on the functional model can be verified comparing with the ideal phase noise graph. As a result of the comparison of simulation time (6 us), the Verilog-HDL-based modeling method (1.43 second) showed 484 times faster than the analog transistor level design (692 second) implemented by TSMC 0.18-㎛.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.62-66
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• 2010

In this article, a oscillator at X-band with a double H-shape metamaterial resonator (DHMR) based on high-Q is proposed with metamaterial structure to improve Ihe phase noise and output power. The proposed oscillator is required low phase noise and high output power for the high performance frequency synthesizer. DHMR is designed to be high-Q at resonance frequency through strong coupling of E-field. This character makes phase noise excellent. The oscillator using DHMR is oscillated in X-band so as to apply frequency synthesizer of radar systems. The output power is 4.33 dBm and the phase noise is -108 dBc/Hz at 100 kHz offset of carrier frequency.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1890-1896
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• 2008

In this paper, the Si vertical Hall devices ale fabricated by using standard bipolar process and investigated in terms of the opeating and noise properties. The sensitivity of device with P+ isolation dam(type B) has been increased up to about 1.2 times compared to that device without the dam also noise has been increased. With the condition of f=I[KHz], band-width 1[Hz], the resolution of magnetic-field detection were about $0.97[{\mu}T]$/ type B and $1.25[{\mu}T]$/ type A, respectively, thus we must consider correlation the low noise or good resolution and high sensitivity in the situation for device geometry design or even for the materials.

• Journal of Biomedical Engineering Research
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• v.20 no.3
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• pp.323-329
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• 1999

This paper proposed a method for the cancellation of the moving artifact which was produced during the detection of drowsiness usmg electrodermal activity signal. Two types of wrist electrode were developed to overcome the defect of the steering wheel type electrode which couldn't eliminate the moving artifacts due to driver's movements. Wrist type electrode II which has been modified from electrode type I was most effective for eliminating movmg artifacts compared to wheel type electrode and wrisL type electrode 1. The decIsion criteria(if IRI$\leq$10 and 1.1$\leq$dNz) for detecting moving artifact was determined from the virtual driving experiments. An algorithm which substituted past value of Nz for the current value of Nz whenever an EDA signal satisfied the criteria was developed. The experimental resulls of virtual driving and road test showed that the proposed algorithm had been successfully removed the most of the error due to the moving artifact Therefore, the developed system which use electrode type II and the algorithm might be less influenced by moving artifacts and could measure an accurate arousal state.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.5
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• pp.811-816
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• 2019

This paper first proposes a technique to separate clean speech signals and mixed noise signals by using an independent vector analysis algorithm of frequency band for 4 channel speech source signals with a noise. An improved output speech signal from the proposed independent vector analysis algorithm is obtained by using the cross-correlation between the signal outputs from the frequency domain delay-sum beamforming and the output signals separated from the proposed independent vector analysis algorithm. In the experiments, the proposed algorithm improves the maximum SNRs of 10.90dB and the segmental SNRs of 10.02dB compared with the frequency domain delay-sum beamforming algorithm for the input mixed noise speeches with 0dB and -5dB SNRs including white noise, respectively. Therefore, it can be seen from this experiment and consideration that the speech quality of this proposed algorithm is improved compared to the frequency domain delay-sum beamforming algorithm.