• 제목/요약/키워드: Digital Signal Processing

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위상천이가법에 의한 디지털 홀로그래피 마이크로스코피에 관한 연구 (Digital Holographic microscopy based on phase shifting technique)

  • 박광희;최평석;은재정
    • 융합신호처리학회논문지
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    • 제12권3호
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    • pp.181-187
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    • 2011
  • 본 논문에서는 홀로그램정보의 손실이 없고, CCD 화소면의 최대 활용이 가능한 in-line 형태의 광학계를 구성하고, 보다 향상된 위상 천이법을 토대로 디지털 in-line 홀로그래피 마이크로스코피를 구현하였다 이러한 구성방식으로 디지털 홀로그래피의 최대 문제인 0차 회절 항에 의한 DC잡음과 in-line 홀로그래피에서 나타나는 트윈 이미지가 효율적으로 제거됨을 실험적으로 보였고, 위상 맵핑을 통해 계량적으로 분석하였다. 또한 광학장치 컨트롤과 영상처리가 연동하여 실시간적으로 이루어지므로, 본 논문에서 연구한 DHM 방식은 앞으로 미세분석을 위한 삼차원 현미경법에 많은 응용이 이루어 질것으로 기대된다.

2D Image Construction from Low Resolution Response of a New Non-invasive Measurement for Medical Application

  • Hieda, Ichiro;Nam, Ki-Chang
    • ETRI Journal
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    • 제27권4호
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    • pp.385-393
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    • 2005
  • This paper presents an application of digital signal processing to data acquired by the radio imaging method (RIM) that was adopted to measure moisture distribution inside the human body. RIM was originally developed for the mining industry; we are applying the method to a biomedical measurement because of its simplicity, economy, and safety. When a two-dimensional image was constructed from the measured data, the method provided insufficient resolution because the wavelength of the measurement medium, a weak electromagnetic wave in a VHF band, was longer than human tissues. We built and measured a phantom, a model simulating the human body, consisting of two water tanks representing large internal organs. A digital equalizer was applied to the measured values as a weight function, and images were reconstructed that corresponded to the original shape of the two water tanks. As a result, a two-dimensional image containing two individual peaks corresponding to the original two small water tanks was constructed. The result suggests the method was applicable to biomedical measurement by the assistance of digital signal processing. This technique may be applicable to home-based medical care and other situations in which safety, simplicity, and economy are important.

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Investigating the Effects of Hearing Loss and Hearing Aid Digital Delay on Sound-Induced Flash Illusion

  • Moradi, Vahid;Kheirkhah, Kiana;Farahani, Saeid;Kavianpour, Iman
    • Journal of Audiology & Otology
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    • 제24권4호
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    • pp.174-179
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    • 2020
  • Background and Objectives: The integration of auditory-visual speech information improves speech perception; however, if the auditory system input is disrupted due to hearing loss, auditory and visual inputs cannot be fully integrated. Additionally, temporal coincidence of auditory and visual input is a significantly important factor in integrating the input of these two senses. Time delayed acoustic pathway caused by the signal passing through digital signal processing. Therefore, this study aimed to investigate the effects of hearing loss and hearing aid digital delay circuit on sound-induced flash illusion. Subjects and Methods: A total of 13 adults with normal hearing, 13 with mild to moderate hearing loss, and 13 with moderate to severe hearing loss were enrolled in this study. Subsequently, the sound-induced flash illusion test was conducted, and the results were analyzed. Results: The results showed that hearing aid digital delay and hearing loss had no detrimental effect on sound-induced flash illusion. Conclusions: Transmission velocity and neural transduction rate of the auditory inputs decreased in patients with hearing loss. Hence, the integrating auditory and visual sensory cannot be combined completely. Although the transmission rate of the auditory sense input was approximately normal when the hearing aid was prescribed. Thus, it can be concluded that the processing delay in the hearing aid circuit is insufficient to disrupt the integration of auditory and visual information.

이진수의 최소 디지트 표현과 공통 부분식 소거법을 이용한 디지털 필터의 성능 개선에 관한 연구 (Study on Performance Improvement of Digital Filter Using MDR of Binary Number and Common Subexpression Elimination)

  • 이영석
    • 한국산학기술학회논문지
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    • 제10권11호
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    • pp.3087-3093
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    • 2009
  • 디지털 필터는 다양한 디지털 신호처리 분야에서 필수 불가결하게 사용되는 기본 요소이다. 디지털 필터는 이진수의 덧셈과 곱셈을 기본 연산으로 하기 때문에 이진수로 나타낸 필터의 계수 및 차수에 의해 연산 속도, 전력소비 등의 성능이 결정 될 뿐만 아니라 VLSI 기술을 이용하여 디지털 필터가 반도체 칩으로 제작되는 경우, 칩의 면적에 영향을 미치게 된다. 본 연구에서는 디지털 필터의 성능을 개선하기 위하여 2의 보수로 표현되는 이진 필터 계수 데이터들에 대하여 0 디지트의 개수를 최대로 표현할 수 있도록 하는 두 가지 알고리즘을 적용하여 필터의 연산속도를 증가 시키고, 공통 부분식 소거법을 적용하여 필터의 덧셈 연산을 간소화 시키며 곱셈 연산을 shift 연산으로 대체하여 디지털 필터 설계를 간단히 할 수 있는 방법을 제시하였다. 제안한 방법은 FPGA를 이용한 디지털 필터로 구현하여 성능을 평가하였다.

CDMA2000 시스템에서 파일럿 채널을 이용한 스마트 안테나 시스템의 성능향상 연구 (Research on Improving Performance Utilizing Pilot Channel of Smart Antenna System in CDMA2000 system)

  • 안성수;김민수
    • 디지털산업정보학회논문지
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    • 제5권3호
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    • pp.99-105
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    • 2009
  • This paper suggests novel signal processing methods for optimal beamforming of smart antenna system in CDMA2000 mobile communication environments. This method utilize characteristics of the reverse pilot channel of CDMA2000 mobile communication systems, and applies them to improve the performance of an adaptive algorithm, which is used to a smart antenna system for beamforming. To perform the best beamforming, it is important to get an exact beamforming algorithm. This paper proposed an algorithm based on Laglange multiplier which has such an adaptive process, and also proposed the method to demodulate the received signal through array antenna using pilot channel in CDMA2000 environment. This paper analysed the enhanced performance of proposed algorithm in various signal environment through signal modeling of physical layer in CDMA2000 reverse link.

CGM 알고리즘을 이용한 중계기 간섭제거기 구현 (Implementation of Interference Cancellation System for Relay Utilizing the CGM Algorithm)

  • 안성수;고정환
    • 디지털산업정보학회논문지
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    • 제8권1호
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    • pp.139-145
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    • 2012
  • This paper shows a novel interference cancellation method of relay utilizing to the CGM algorithm in wireless communication environments. It is a problem that relay have interference cause by feedback signal of it. CGM algorithm obtained weight value that can remove the interference due to feedback signal of relay. In this paper, we confirm that performance of CGM algorithm is far superior with suitable cancellation value to remove the feedback signal. Also, we implement CGM module to verify the real-time processing of CGM algorithm using to DSP. Based on the analysis from computer simulation, it is observed that proposed algorithm is suitable for the relay in time-varying environment.

Average 출력회로를 이용한 아날로그 병렬처리 기반 비터비 디코더 (Analog Parallel Processing-based Viterbi Decoder using Average circuit)

  • 김현정;김인철;김형석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.375-377
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    • 2006
  • A Analog parallel processing-based Viterbi decoder which decodes PRML signal of DVD has been designed by CMOS circuit. The analog processing-based Viterbi decoder implements are functions of the conventional digital Viterbi decoder utilizing the analog parallel processing circuit technology. The Analog parallel processing-based Viterbi decoding technology is applied for the PR(1,2,2,1) signal decoding of DVD. The benefits are low power consumption and less silicon consumption. In this paper, the comparison of the Analog parallel processing-based Viterbi Decoder which has a function of the error correction between Max operation and Average operation is discussed.

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마이크로 프로세서를 이용한 디지털 보정회로 설계 (Design of Digital Correction Circuits Using Microprocessor)

  • 전호익;조현섭
    • 한국산학기술학회논문지
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    • 제12권5호
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    • pp.2291-2293
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    • 2011
  • 본 논문에서는 유연성 있는 신호처리 방법으로 디지털 로직을 컴퓨터 논리연산 명령으로 구성하여 외부에서의 입력신호에 대응하는 논리연산의 결과를 입출력 채널을 통해 외부로 출력해 줄 수 있는 드라이브에 관한 연구이다. 이는 Decoder IC Multiplexer & Demulti Plexer, 기본 로직 IC 등의 가상구현 및 BIT출력이 가능한 디지털 신호원으로서의 기능이 가능하며 일반 산업체에서 유용하게 사용될 수 있으리라 사료된다.

Energy-Efficient Approximate Speech Signal Processing for Wearable Devices

  • Park, Taejoon;Shin, Kyoosik;Kim, Nam Sung
    • ETRI Journal
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    • 제39권2호
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    • pp.145-150
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    • 2017
  • As wearable devices are powered by batteries, they need to consume as little energy as possible. To address this challenge, in this article, we propose a synergistic technique for energy-efficient approximate speech signal processing (ASSP) for wearable devices. More specifically, to enable the efficient trade-off between energy consumption and sound quality, we synergistically integrate an approximate multiplier and a successive approximate register analog-to-digital converter using our enhanced conversion algorithm. The proposed ASSP technique provides ~40% lower energy consumption with ~5% higher sound quality than a traditional one that optimizes only the bit width of SSP.

자율주행 무인차량용 레이더 신호처리부 개발 및 성능 분석 (Development and Performance Analysis of Radar Signal Processing for Autonomous Unmanned Ground Vehicle)

  • 신승용;최준혁;박상현;염동진;김정렬
    • 한국군사과학기술학회지
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    • 제16권4호
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    • pp.514-522
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    • 2013
  • In this paper, we present signal processing procedure and carry out performance analysis of FMCW(Frequency Modulation Continuous Wave) radar for Autonomous Unmanned Vehicle(AUV). In order to detect range profile and velocity of the unknown target, we must implement two step FFT(Fast Fourier Transform) procedure. And the DBF(Digital Beam Forming) algorithm has to be performed to obtain the angle information of the unknown target. To verify the performance of manufactured autonomous unmanned ground vehicle FMCW radar, we use the data of the real corner reflecter target.