• 한국항행학회논문지
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• 제2권2호
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• pp.75-83
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• 1998

본 논문에서는 저가이면서 높은 정확도를 갖는 GPS와 DR의 통합시스템 및 이 시스템의 위치 결정에 수반되는 오차문제를 고려한다. 이 통합 GPS/DR 시스템은 실시간 또는 비 실시간으로 고정밀도의 위치 정보를 제공하는 성능을 갖는다. DR 측정치에 영향을 주는 주요 오차 요인을 분석하여 이를 8개의 상태 변수의 모델로 표현하였다. 이들 변수의 상태 방정식을 사용하여 DR신호가 제공되는 매 순간에서 상태 변수값을 추산하기 위한 통합시스템용 비선형 필터를 개발한다, 1Hz의 DR 측정치와 3Hz로 제공되는 GPS 위치 정보를 위치 추산치에 대해 이 통합시스템의 정확도를 평가한다. 시뮬레이션을 통해 GPS신호가 정전되는 기간동안 통합 시스템의 성능을 두 가지 서로 다른 잡음모델에 대해 비교 검토한다. 두 잡음모델 중 하나는 단일잡용을 사용하는 반면에 또 다른 모델은 이중 잡음 모델을 채용한다. 시뮬레이션 결과로부터 이중 잡음 모델을 채용하는 GPS/DR 통합시스템은 단일 잡음 모델을 이용하는 경우에 비하여 측위성능이 우수함을 확인하였다.

• ETRI Journal
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• 제34권2호
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• pp.190-198
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• 2012

An adaptive correlation noise model (CNM) construction algorithm is proposed in this paper to increase the efficiency of parity bits for correcting errors of the side information in transform domain Wyner-Ziv (WZ) video coding. The proposed algorithm introduces two techniques to improve the accuracy of the CNM. First, it calculates the mean of direct current (DC) coefficients of the original WZ frame at the encoder and uses it to assist the decoder to calculate the CNM parameters. Second, by considering the statistical property of the transform domain correlation noise and the motion characteristic of the frame, the algorithm adaptively models the DC coefficients of the correlation noise with the Gaussian distribution for the low motion frames and the Laplacian distribution for the high motion frames, respectively. With these techniques, the proposed algorithm is able to make a more accurate approximation to the real distribution of the correlation noise at the expense of a very slight increment to the coding complexity. The simulation results show that the proposed algorithm can improve the average peak signal-to-noise ratio of the decoded WZ frames by 0.5 dB to 1.5 dB.

• 환경영향평가
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• 제21권6호
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• pp.893-901
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• 2012

Aircraft noise model such as FAA Integrated Noise Model(INM) has recently been used for forecasting the impact of noise in a residential area near an airport and quantifying the effect of various options for noise mitigation. The noise modeling should be reliable and precise in order to ensure the quality of the results provided. In this study, the validation of the noise levels simulated by the INM against measurement data recorded continuously at multiple monitoring sites was discussed. As a result of validation, the quality of the input data used as a fixed point profiles for the INM was enhanced. The noise contour maps were designed as a way to evaluate the aircraft noise of the vicinity of the airfield. The results of this study indicate that the validation of aircraft noise model by the measurement data would be required for the accurate assessment of the aircraft noise levels.

• 전자공학회논문지C
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• 제35C권7호
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• pp.11-19
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• 1998

A signal line potential variation due to the delta-I noise was physically investigated in CMOS integrated circuits. An equivalent circuit for the noise analysis was presented. The signal line was modeled as segmented RC-lumped circuits with the ground noise. Then the equivalent circuit was mathematically analyzed. Therebvy a new signal line potential variation model due to the switching mosie was developed. Th emodel was verified with 0.35.mu.m CMOS deivce model parameters. The model has an excellent agreement with HSPICE simulation. Thus the proposed model can be dirctly employed in the industry to design the high-performance integrted circuit design as well as integrated circuit package design.

• ETRI Journal
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• 제46권1호
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• pp.22-34
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• 2024

Exposure to varied noisy environments impairs the recognition performance of artificial intelligence-based speech recognition technologies. Degraded-performance services can be utilized as limited systems that assure good performance in certain environments, but impair the general quality of speech recognition services. This study introduces an audiovisual speech recognition (AVSR) model robust to various noise settings, mimicking human dialogue recognition elements. The model converts word embeddings and log-Mel spectrograms into feature vectors for audio recognition. A dense spatial-temporal convolutional neural network model extracts features from log-Mel spectrograms, transformed for visual-based recognition. This approach exhibits improved aural and visual recognition capabilities. We assess the signal-to-noise ratio in nine synthesized noise environments, with the proposed model exhibiting lower average error rates. The error rate for the AVSR model using a three-feature multi-fusion method is 1.711%, compared to the general 3.939% rate. This model is applicable in noise-affected environments owing to its enhanced stability and recognition rate.

• 산업기술연구
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• 제27권B호
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• pp.59-64
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• 2007

This study introduces an environmental noise evaluation procedure and results for a wind turbine (W/T) system. Test and evaluation are required by the international standard IEC 61400-11 in the aspect of environmental effect. Test and evaluation are performed on U-50 WT model which is first developed by the domestic W/T manufacturer. W/T test model is under operation in Daekwanryung wind test site. An integrated monitoring system in the test site is utilized for the evaluation. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level are estimated and compared with those of other similar size WT under the wind speeds required by international standard.

• 융합정보논문지
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• 제9권9호
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• pp.141-146
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• 2019

여러 종류의 항공기가 운용되고 있는 훈련 비행장에서 항공기의 소음을 실제 측정하여 분석하는 것은 어렵다. 이러한 실제적인 한계를 극복하고 적절한 소음 대책을 수립하기 위해서 FAA에서 사용하는 INM 7.0(Integrated Noise Model Version 7.0)을 사용하여 소음 지도를 작성하였다. 터보프롭 항공기 (C90GT)가 이륙 경로, 착륙 경로 및 장주경로를 비행하면서 발생하는 소음을 측정하였고 법적으로 소음의 피해가 되는 70 WECPNL 이상인 지역을 조사하였다. 터보프롭 항공기가 운용되고 있는 모든 경로에서 70 WECPNL을 초과하는 지역은 발견되지 않았다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.241-245
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• 2005

This study introduces the wind turbine (W/T) noise evaluation procedure required in the international standard (IEC 61400-11) and monitoring system for the evaluation. Noise emission characteristics of a 750kW W/T generator is investigated. Test and evaluation are performed on J48 W/T model which is under operation in Daekwanryung Wind Test Site. With the noise signal, meteorological data and W/T operational data are monitored in real time by the integrated monitoring system using LabVIEW. From the measured noise data, acoustic power level and tonality of the W/T are estimated under the wind speeds required by the international standard.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
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• pp.728-734
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• 1998

Aircraft noise is one of the main causes of environmental impact. It is more serious than any other noise nuisance. It has become an increasing source of annoyance to the large number of people who live in communities near airports. This paper demonstrates the prediction of aircraft noise using Integrated Noise Model(INM) 5.1 developed by U.S. FAA and aircraft noise contour map near airports.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.110-116
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• 2000

Aircraft noise is one of the main causes of environmental impact. It is more serious than any other noise nuisance. It has become an increasing source of annoyance to the large number of people who live in communities near airports. This paper demonstrates the prediction of aircraft noise using Integrated Noise Model (INM) 5.1 developed by U.S. FAA and aircraft noise contour map near airports.