• Title/Summary/Keyword: Impulse Responses

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Selective impairment of the rapid eye movements in myotonic dystrophy

  • Kim, Sung-Hee;Park, Jin-Sung
    • Annals of Clinical Neurophysiology
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    • v.21 no.2
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    • pp.94-97
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    • 2019
  • The patients with myotonic dystrophy (MD) show ocular motor abnormalities including strabismus, vergence deficits, and inaccurate or slow saccades. Two theories have been proposed to explain the oculomotor deficits in MD. The central theory attributes the defects of eye movements of MD to the involvement of the central nervous system while the muscular theory attributes to dystrophic changes of the extraocular muscles. A 58-year-old woman with MD showed selective slowing of horizontal saccades and reduced peak velocities for both horizontal canals in head impulse tests, while smooth-pursuit eye movements and vertical head impulse responses were normal. This case suggests that the extraocular muscles-as a final common pathway of the voluntary saccade and reflexive vestibular eye movements-may better explain the defective rapid eye movements observed in MD.

Fast Convolution Method using Psycho-acoustic Filters in Sound Reverberator (잔향 생성기에서 심리 음향 필터를 이용한 고속 컨벌루션 방법)

  • Shin, Min-Cheol;Wang, Se-Myung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1037-1041
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    • 2007
  • With the advent of sound field simulator, many sound fields have been reproduced by obtaining the impulse responses of specific acoustic spaces like famous concert hall, opera house. This sound field reproduction has been done by the linear convolution operation between the sound input signal and the impulse response of certain acoustic space. However, the conventional finite impulse response based linear convolution operation always makes real-time implementation of sound field generator impossible due to the large amount of computational burden. This paper introduces the fast convolution method using perceptual redundancy in the processed signals, input audio signal and room impulse response. Temporal and spectral psycho-acoustic filters considering masking effects are implemented in the proposed convolution structure. It reduces the computational burden of convolution methods for realtime implementation of a sound field generator. The conventional convolutions are compared with the proposed one in views of computational burden and sound quality. In the proposed method, a considerable reduction in the computational burden was realized with acceptable changes in sound quality.

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Fast Convolution Method Using Real-time Masking Effects in Sound Reverberator (잔향 생성기에서 실시간 마스킹 효과를 이용한 고속 컨벌루션 방법)

  • Shin, Min-Cheol;Wang, Se-Myung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.2
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    • pp.231-237
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    • 2008
  • With the advent of sound field simulator, many sound fields have been reproduced by obtaining the impulse responses of specific acoustic spaces like famous concert hall, opera house. This sound field reproduction has been done by the linear convolution operation between the sound input signal and the impulse response of certain acoustic space. However, the conventional finite impulse response based linear convolution operation always makes real-time implementation of sound field generator impossible due to the large amount of computational burden. This paper introduces the fast convolution method using perceptual redundancy in the processed signals, input audio signal and room impulse response. Temporal and spectral real-time masking blocks are implemented in the proposed convolution structure. It reduces the computational burden of convolution methods for real-time implementation of a sound field generator. The conventional convolutions are compared with the proposed one in views of computational burden and sound quality. In the proposed method, a considerable reduction in the computational burden was realized with acceptable changes in sound quality.

Factors Characterizing the Pulse-mode Performance of Monopropellant Hydrazine Thrusters (하이드라진 추력기의 펄스모드 성능특성인자 해석)

  • Kim, Jeong-Soo;Park, Jeong;Lee, Jae-Won;Kim, In-Tae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.399-404
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    • 2010
  • Test results including the variation of propellant-inlet pressure, pulsed thrust, and environment vacuum with the accompanying thermal responses are presented for the pulse-mode operation of a set of monopropellant hydrazine thrusters producing $0.95lb_f$ of nominal steady-state thrust at an inlet pressure of 350 psia. The test data are reduced into the impulse bit, specific impulse, and force centroid that are the factors typically characterizing pulse-mode performance of small rocket engines. With a scrutiny to the performance parameters, their comparison to the reference criteria of 1 lbf standard monopropellant rocket engine are successfully made.

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Characterization and Analysis of UWB Antennas in Time Domain (시간 영역에서의 초광대역 안테나 특성 해석)

  • Song Jong-Hwa;Park Young-Jin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.3 s.106
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    • pp.287-294
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    • 2006
  • In the paper, characterization and analysis of UWB(Ultra Wide Band) antennas in time domain are described. The impulse propagation channel including UWB antennas is proposed for the analysis in time domain. Using the proposed propagation channel, the technique of obtaining impulse response of UWB antenna is proposed. Also, ringing, peak value of the impulse response, and the width of the impulse response are introduced as parameters for characterizing a UWB antenna in time domain. A modified UWB conical monopole antenna, a UWB TEM horn antenna, and a UWB stepped fat monopole antenna were fabricated. From the measurement of reflection coefficients, three antennas had bandwidth more than 3 GHz. The impulse responses of the antennas were measured in an anechoic chamber. The results showed that the TEM horn with highest gain has the highest peak amplitude and the stepped fat monopole antenna with narrowest bandwidth for reflection coeffcient had the widest width of the impulse response. Also, ringing in the stepped fat monopole antennas and the UWB conical monopole antenna were observed.

New accuracy indicator to quantify the true and false modes for eigensystem realization algorithm

  • Wang, Shuqing;Liu, Fushun
    • Structural Engineering and Mechanics
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    • v.34 no.5
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    • pp.625-634
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    • 2010
  • The objective of this paper is to apply a new proposed accuracy indicator to quantify the true and false modes for Eigensystem Realization Algorithm using output-based responses. First, a discrete mass-spring system and a simply supported continuous beam were modelled using finite element method. Then responses are simulated under random excitation. Natural Excitation Technique using only response measurements is applied to compute the impulse responses. Eigensystem Realization Algorithm is employed to identify the modal parameters on the simulated responses. A new accuracy indicator, Normalized Occurrence Number-NON, is developed to quantitatively partition the realized modes into true and false modes so that the false portions can be disregarded. Numerical simulation demonstrates that the new accuracy indicator can determine the true system modes accurately.

Analysis of the Asymmetric Interest rate Adjustments in Banks and Non-Bank Depository Institutions (은행 및 비은행 예금취급기관의 비대칭적 금리조정 분석)

  • Eui-hwan Park
    • Asia-Pacific Journal of Business
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    • v.15 no.2
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    • pp.223-236
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    • 2024
  • Purpose - The purpose of the paper is to empirically investigate the asymmetric adjustment of loan and deposit interest rates among banks and non-bank depository institutions. Design/methodology/approach - We construct a VAR model using time series data comprising loan and deposit interest rates of banks and non-bank depository institutions, along with the call rate. Based on this model, we conduct impulse-response analysis and variance decomposition to investigate the dynamic relationship between the interest rates. Findings - In the case of banks and credit unions, the responses of deposit rates to the call rate are larger than the responses of loan rates, and we cannot find evidence of non-linear responses. In the case of savings banks, the responses of loan rates to the call rate are larger than the responses of deposit rates. The responses of loan rates to a positive call rate shock are statistically significant, while the responses of loan rates to a negative call rate shock are not statistically significant. Research implications or Originality - This study differs from previous research in that it examines the asymmetric response of loan and deposit rates of both banks and non-bank financial institutions to changes in the call rate. The implications for the impact of these findings on the financial system and income inequality are presented.