• Title/Summary/Keyword: 블라인드 디컨볼루션

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Application of ray-based blind deconvolution to long-range acoustic communication in deep water (음선 기반 블라인드 디컨볼루션의 장거리 심해 환경으로의 적용)

  • Kim, Donghyeon;Park, Heejin;Kim, J.S.;Hahn, Joo Young
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.2
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    • pp.242-253
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    • 2022
  • When the source waveform is unknown, the Green's function can be estimated by Ray-based Blind Deconvolution (RBD) based on the simple array signal processing. In previous papers, RBD was successfully demonstrated using simulation and experiments in shallow water environment. In this paper, we investigate the applicability of RBD for a long-range communication (e.g., 30 km, 60 km, and 90 km) in a deep water environment (1,000 m ~), using experimental data conducted in the east of Pohang, South Korea, in October 2018. Data results are presented to demonstrate Green's function estimation of a communication signal (2.2 kHz ~ 2.9 kHz) using a 16-element, 42-m long vertical array. The results show that the Green's function estimated from RBD is comparable to that of matched filter result. Additional communication performance at a maximum range of 90 km will be also presented.

Performance improvement of underwater acoustic communication using ray-based blind deconvolution in passive time reversal mirror (수동형 시역전 기반의 음선 기반 블라인드 디컨볼루션 기법을 이용한 수중음향통신 성능 개선)

  • Oh, Se Hyun;Byun, Gi Hoon;Kim, J.S.
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.5
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    • pp.375-382
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    • 2016
  • This paper presents the results for the performance improvement of underwater communication in a passive time reversal mirror (PTRM) using ray-based blind deconvolution (RBD). In conventional PTRM, the signal to be recovered is found from matched-filtering the received probe signal. However, the communication performance is degraded because the time-varying impulse response for each data frame is not reflected in the received probe signal. In this study, the time-variant transfer function is estimated from each received data frame using RBD, and the estimated time-variant transfer function is then used to recover the data signal using PTRM. The results from the experimental data show that the suggested method improves the communication performance when comparing with the conventional PTRM.

Estimation of source signal and channel response using ray-based blind deconvolution technique for Doppler-shifted underwater channel (음선 기반 블라인드 디컨볼루션 기법을 이용한 수중 도플러 편이 채널에서의 송신 신호 및 채널 응답 추정)

  • Byun, Gi Hoon;Oh, Se Hyun;Byun, Sung-Hoon;Kim, J.S.
    • The Journal of the Acoustical Society of Korea
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    • v.35 no.5
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    • pp.331-339
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    • 2016
  • This paper suggests an estimation method of the source signal and the channel impulse response (CIR) using ray-based blind deconvolution (RBD) in the underwater acoustic channel environment where Doppler effect exists by the relative motion between source and receiver. It is difficult to estimate the CIR on Doppler effect by the matched filter with a highly Doppler-sensitive waveform such as the m-sequence signal because Doppler shift can severely degrade the correlation between the received signal corrupted by Doppler effect and the original source signal. In this study, the Doppler-shifted source-signal's phase is estimated using the RBD, and the received signal is compensated by it to obtain the Doppler-corrected CIR. It is verified that using the matched filter with the received signal from the experimental data fails to estimate the CIR while the obtained CIR by the suggested method has the similarity to the propagation path of the ray model. Also, the results show that the reconstructed source signal using the RBD has the better Doppler shift compensation than the Doppler-shifted source signal derived from scattering function.

Performance improvement of underwater target distance estimation using blind deconvolution and time of arrival method (블라인드 디컨볼루션 및 time of arrival 기법을 이용한 수중 표적 거리 추정 성능 향상 기법)

  • Han, Min Su;Choi, Jea Young;Son, Kweon;Lee, Phil Ho
    • The Journal of the Acoustical Society of Korea
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    • v.36 no.6
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    • pp.378-386
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    • 2017
  • Accurate distance measurement between maneuver target in underwater and measuring devices is required to perform quantitative test evaluation in marine weapons system R&D process. In general, the target distance is measured using a one-way ToA (Time of Arrival) method that calculates the time difference between transmitted and received signals from the two accurately synchronized devices. However, the distance estimation performance is degraded because of the multi-path environments. In this paper, the time-variant transfer function of complex underwater environment is estimated from each received data frame using RBD (Ray-based Blind Deconvolution), and the estimated time-variant transfer function is then used to get rid of the effect about complex underwater environment and to recover the data signal using PTRM (Passive Time Reversal Mirror). The result from the simulation and experimental data show that the suggested method improve the distance estimation performance when comparing with the conventional ToA method.

A Study on Image Resolution Increase According to Sequential Apply Detector Motion Method and Non-Blind Deconvolution for Nondestructive Inspection (비파괴검사를 위한 검출기 이동 방법과 논블라인드 디컨볼루션 순차 적용에 따른 이미지 해상도 증가 연구)

  • Soh, KyoungJae;Kim, ByungSoo;Uhm, Wonyoung;Lee, Deahee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.6
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    • pp.609-617
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    • 2020
  • Non-destructive inspection using X-rays is used as a method to check the inside of products. In order to accurately inspect, a X-ray image requires a higher spatial resolution. However, the reduction in pixel size of the X-ray detector, which determines the spatial resolution, is time-consuming and expensive. In this regard, a DMM has been proposed to obtain an improved spatial resolution using the same X-ray detector. However, this has a limitation that the motion blur phenomenon, which is a decrease in spatial resolution. In this paper, motion blur was removed by applying Non-Blind Deconvolution to the DMM image, and the increase in spatial resolution was confirmed. DMM and Non-Blind Deconvolution were sequentially applied to X-ray images, confirming 62 % MTF value by an additional 29 % over 33 % of DMM only. In addition, SSIM and PSNR were compared to confirm the similarity to the 1/2 pixel detector image through 0.68 and 33.21 dB, respectively.

Analysis on Optimal Approach of Blind Deconvolution Algorithm in Chest CT Imaging (흉부 컴퓨터단층촬영 영상에서 블라인드 디컨볼루션 알고리즘 최적화 방법에 대한 연구)

  • Lee, Young-Jun;Min, Jung-Whan
    • Journal of radiological science and technology
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    • v.45 no.2
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    • pp.145-150
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    • 2022
  • The main purpose of this work was to restore the blurry chest CT images by applying a blind deconvolution algorithm. In general, image restoration is the procedure of improving the degraded image to get the true or original image. In this regard, we focused on a blind deblurring approach with chest CT imaging by using digital image processing in MATLAB, which the blind deconvolution technique performed without any whole knowledge or information as to the fundamental point spread function (PSF). For our approach, we acquired 30 chest CT images from the public source and applied three type's PSFs for finding the true image and the original PSF. The observed image might be convolved with an isotropic gaussian PSF or motion blurring PSF and the original image. The PSFs are assumed as a black box, hence restoring the image is called blind deconvolution. For the 30 iteration times, we analyzed diverse sizes of the PSF and tried to approximate the true PSF and the original image. For improving the ringing effect, we employed the weighted function by using the sobel filter. The results was compared with the three criteria including mean squared error (MSE), root mean squared error (RMSE) and peak signal-to-noise ratio (PSNR), which all values of the optimal-sized image outperformed those that the other reconstructed two-sized images. Therefore, we improved the blurring chest CT image by using the blind deconvolutin algorithm for optimal approach.

Study on Efficient Image Restoration using Reference Image (기준 영상을 활용한 효율적 영상 복원에 관한 연구)

  • Kim, Intaek;Awan, Tayyab Wahab
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.3
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    • pp.645-650
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    • 2015
  • Image restoration is required when the image is blurred due to out of focus or motion during the image acquisition. This type of image restoration is known as ill-posed inverse problem because the estimate of an original image should be derived from only one blurred image. This paper introduces a reference image to facilitate the restoration process. The experimental result shows that computation time is significantly reduced, compared with other methods. The proposed method obtains the estimate of the kernel used in blurring processing. New cost function is defined to update both the image and the kernel alternately. In the last stage, Wiener filter produces the estimate of an original image using the kernel and the reference image.