• Title/Summary/Keyword: mixed noise

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Digital Filter based on Noise Estimation for Mixed Noise Removal (복합잡음 제거를 위한 잡음추정에 기반한 디지털 필터)

  • Cheon, Bong-Won;Hwang, Yong-Yeon;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.404-406
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    • 2021
  • In modern society, artificial intelligence and automation are being applied in various fields due to the development of the 4th industrial revolution and IoT technology. In particular, systems with a high proportion of image processing, such as automated processes, intelligent CCTV, medical industry, robots, and drones, are susceptible to external factors noise. In this paper, we propose a digital filter based on noise estimation and weights to reconstruct an image in a complex noise environment. The proposed algorithm classifies the types of noise using noise judgment, and determines the noise level of the filtering mask to switch the filtering process to obtain the final output. In order to verify the performance of the proposed algorithm, simulation was conducted, compared with the existing filter algorithm, and the results were analyzed.

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A Study on Design of Elementary Schoolhouse for Mixed-use Facilities (초등학교 교사의 복합용도계획에 관한 연구)

  • Lee, Hyun-Jae;Kang, Chul-Hee
    • Korean Institute of Interior Design Journal
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    • v.17 no.1
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    • pp.138-145
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    • 2008
  • This study is conducted to formulate various spatial compositions for mixed-use elementary schools in order to use them as community centers. Accordingly, this study is conducted to analyze currently operating community-use elementary schools to find out about the current condition of mixed-use facilities, and the types of mixed-use facilities will be derived from the analysis. In addition, a more effective method of planning mixed-use elementary schools is investigated. By incorporating various educational curricula and teaching/learning activities, major points, which should be considered when planning elementary schools, will be suggested to effectively respond to the changes of educational environment in the future. The results show that in terms of inner traffic flow type, 9 schools out of the schools under study showed a unificated traffic flow type or a cross traffic flow type. When traffic overlaps, problems of noise, visual distraction, and decreased learning performance can appear. To prevent the conflict between areas and to manage areas effectively, each area should be differentiated by installing doors and shutters and by marking guides, and the facility used for community residents and students should also be scheduled separately to avoid time conflict. In addition, to accommodate the changes of users, flexible space planning options should be considered.

Creation and Assessment of Korean Speech and Noise DB in Car Environments (자동차 환경에서의 노이즈 DB 및 한국어 음성 DB 구축)

  • Lee Kwang-Hyun;Kim Bong-Wan;Lee Yong-Ju
    • MALSORI
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    • no.48
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    • pp.141-153
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    • 2003
  • Researches into robust recognition in noise environments, especially in car environments, are being carried out actively in speech community. In this paper we will report on three types of corpora that SiTEC (Speech Information TEchnology & industry promotion Center) has created for research into speech recognition in car noise environments. The first is the recordings of 900 Korean native speakers, distributed according to gender, age, and region, who uttered application words in car environments. The second is the collections of mixed noise in 3 car types by model while setting up various noise patterns which can be obtained with the car engine on or off, at different driving speed, and in different road conditions with windows open or closed. The third is the recordings of simulated speech by HATS (Head and Torso Simulator) in car environments with the internal and external noise factors added. These three types of recordings were all made through synchronized 8 channel microphones that are fixed in a car. The creation and applications of these corpora will be reported on in detail.

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A Study on Modified Switching Filter for Edge Preservation in Mixed Noise Environments (복합잡음 환경에서 에지 보존을 위한 변형된 스위칭 필터에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.10a
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    • pp.393-396
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    • 2016
  • Digital image processing is the technical area of processing and analysis with intellectual and efficient ways, which has been commercialized in a variety of applications. However, the noise is occurred in the image data with multiple reasons and various studies have been performed to eliminate the noise. Generally, the types of noise vary by causes and forms, and composite noise is the representative one. Hence, the modified switching filter to process by types of noise was suggested to eliminate composite noise in the image effectively and to have excellent characteristics of edge conservation.

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Noise Robust Automatic Speech Recognition Scheme with Histogram of Oriented Gradient Features

  • Park, Taejin;Beack, SeungKwan;Lee, Taejin
    • IEIE Transactions on Smart Processing and Computing
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    • v.3 no.5
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    • pp.259-266
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    • 2014
  • In this paper, we propose a novel technique for noise robust automatic speech recognition (ASR). The development of ASR techniques has made it possible to recognize isolated words with a near perfect word recognition rate. However, in a highly noisy environment, a distinct mismatch between the trained speech and the test data results in a significantly degraded word recognition rate (WRA). Unlike conventional ASR systems employing Mel-frequency cepstral coefficients (MFCCs) and a hidden Markov model (HMM), this study employ histogram of oriented gradient (HOG) features and a Support Vector Machine (SVM) to ASR tasks to overcome this problem. Our proposed ASR system is less vulnerable to external interference noise, and achieves a higher WRA compared to a conventional ASR system equipped with MFCCs and an HMM. The performance of our proposed ASR system was evaluated using a phonetically balanced word (PBW) set mixed with artificially added noise.

Design of On-line Process Control with Variable Measurement Interval

  • Park, Changsoon
    • Journal of the Korean Statistical Society
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    • v.29 no.3
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    • pp.319-336
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    • 2000
  • A mixed model with a white noise process and an IMA(0,1,1) process is considered as a process model. It is assumed that the process is a white noise in the absence of a special cause and the process changes to an IMA(0,1,1) due to a special cause. One useful scheme in measuring the process level is to use the variable measurement interval (VMI) between measurement times according to the value of the previous chart statistic. The advantage of the VMI scheme is to measure the process level infrequently when in control to save the measurement cost and to measure frequently when out of control to save the off-target cost. This paper considers the VMI scheme in order to detect changes in the process model from a white noise to an IMA(0,1,1). The VMI scheme is shown to be effective compared to the standard fixed measurement interval (FMI) scheme in both statistical and economic contexts.

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Effects of noise on coincidence detection in an optical system with entangled state photons (얽힘상태 광을 이용한 광학계에서 잡광이 동시계수에 미치는 영향)

  • 김헌오;고정훈;박구동;엄영호;김태수
    • Korean Journal of Optics and Photonics
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    • v.12 no.4
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    • pp.263-269
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    • 2001
  • The influences of background and environmental noise on coincidence detection are investigated with entangled photons produced by parametric down-conversion process. When the down-converted photons are mixed with thermal light, the coincidence rate did not vary with increasing noise level because the accidental coincidences are discriminated at the short resolving time window. The entangled photon source and the coincidence technique can effectively be used for a noise-free communication channel in the new field of quantum information transmission and processing. ssing.

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Image Restoration Algorithm for Image Noise Removal in Mixed Noise Environment (복합잡음 환경에서 영상 잡음제거를 위한 영상복원 알고리즘)

  • Long, Xu;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.112-114
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    • 2014
  • Generally, images are corrupted by the impulse or AWGN and there are cases where both of these noises are added at once. When it comes to eliminating the noises added to the image, the previous median filter is effective in removing the impulse noise and the average filter is effective for removing AWGN. However, when the complex noises are added, it lacks the noise suppression characteristics, thus in this paper, a non-linear filter algorithm for removing the complex noises was proposed. The simulation results shows the proposed algorithm has excellent de-noising capabilities of compare existing methods.

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Noise Cancellation using Microphone Array in Digital Hearing Aids (디지털 보청기에서 마이크로폰 어레이를 이용한 잡음제거)

  • Bang, Dong-Hyeouck;Kil, Se-Kee;Kang, Hyun-Deok;Yoon, Gwang-Sub;Lee, Sang-Min
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.4
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    • pp.857-866
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    • 2009
  • In this paper, a noise cancellation-method using microphone array for digital hearing aids is proposed. The microphone array is located around the ear of a dummy. Speech sound is generated from the forward speaker positioned in the front of the dummy and noise sound is generated from the backward speaker. The speech and noise are mixed in the air space and entered into the microphones. VAD(voice activity detector) and ANC(adaptive noise cancellation) methods were used to eliminate noise in the sound of the microphones. 10 two-syllable words and 4 sentences were used for speech signals. Babble and car interior noise were used for noise signals. The performance of the proposed algorithm was evaluated by SNR(signal-to-noise ratio) and PESQ-MOS(perceptual evaluation of speech quality-mean opinion score). In babble noise condition, SNR was improved as much as $7.963{\pm}1.3620dB\;and\;3.968{\pm}0.6659dB$ for words and sentences respectively. In the case of car interior noise, SNR was improved as $10.512{\pm}2.0665dB\;and\;6.000{\pm}1.7642dB$ for words and sentences respectively. PESQ-MOS of the babble noise was improved as much as $0.1722{\pm}0.0861$ score for words and $0.083{\pm}0.0417$ score for sentences. And PESQ-MOS of the car interior noise was improved as $0.2661{\pm}0.0335$ score and $0.040{\pm}0.0201$ score for words and sentences respectively. It is verified that the proposed algorithm has a good performance in noise cancellation of microphone array for digital hearing aids.

Adaptive Noise Canceller by Weight Updating Control Method for Speech Enhancement (음성향상을 위한 가중치 갱신제어방식의 적응소음제거기)

  • Kim, Gyu-Dong;Lee, Yun-Jung;Kim, Pil-Un;Chang, Yong-Min;Cho, Jin-Ho;Kim, Myoung-Nam
    • Journal of Korea Multimedia Society
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    • v.10 no.8
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    • pp.1004-1016
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    • 2007
  • In this paper we proposed a Weight-Update-Control Adaptive Noise Canceller which improves speech when environmental noise is stationary and it is hard to acquire a reference signal. Adaptive Noise Canceller(ANC) needs a reference signal, but it is not easy to measure pure noise without voice for reference in factory. Because there are mixed various mechanical noise and workers' voice. Therefore ANC is not suitable to reduce background noise. So we proposed the method that uses an arbitrary constant as an input signal and inputs microphone signal to the reference signal. The noise is eliminated using updated weights in non-speech range. In speech range the weight is fixed and the modified voice is acquired then voice is restored through transversal filter. The proposed method is based on facts that the factory noise is stationary and the noise is not changed in short conversation range. As a result of simulation using MATLAB, we confirmed that the proposed method is effective for reducing factory noise and has high signal to noise ratio(SNR).

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