• Title/Summary/Keyword: Frequency response

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Fast Graphic Visualization of Frequency Response for Audio Equalizer (오디오 이퀄라이저를 위한 주파수 응답의 고속 그래픽 표현 방법)

  • Kim, Ki-Jun;Park, Hochong
    • Journal of Broadcast Engineering
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    • v.20 no.4
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    • pp.632-640
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    • 2015
  • This paper proposes a new method for fast graphic visualization of accurate frequency response of audio equalizer (EQ). When a logarithmic frequency scale is used, a frequency response in high resolution is required for accurate low-band frequency response. However, the high-resolution frequency response requires a huge amount of computational load, which makes the real-time graphic visualization of frequency response impossible. In order to solve the problem of computational load, the proposed method utilizes a low-resolution virtual frequency response in the mid band. It first computes the virtual frequency response of each filter of EQ in the mid band, and then moves it to the target band so that the result corresponds to the desired filter response. Then, it determines the final frequency response of EQ by combining all filter responses. The experiments confirm that the proposed method provides the frequency response of EQ which has an equivalent shape to that computed in high frequency resolution with huge computational load.

Convergence Characteristics of the Frequency Response Functions of Non-Linear Systems Expressed in Terms of the Volterra Series (Volterra급수로 나타낸 비선형시스템 주파수응답함수의 수렴특성)

  • ;Tomlinson, G. R.
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1901-1906
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    • 1995
  • The frequency response functions of systems incorporating a non-linear cubic stiffness subject to sinusoidal excitation are derived using the Volterra series and the convergence characteristics investigated. It is shown that the series representation of the frequency response functions converges only when the sinewave input amplitude is within a certain range. Within the range of convergence the frequency response function based on the Volterra series approaches the analytical one as more higher order frequency response function terms are included. Proposed is a criterion for the studies systems to predict approximately the range of sinewave input amplitude for which the series representation of the frequency response functions converges.

An accurate substructural synthesis approach to random responses

  • Ying, Z.G.;Zhu, W.Q.;Ye, S.Q.;Ni, Y.Q.
    • Structural Engineering and Mechanics
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    • v.39 no.1
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    • pp.47-75
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    • 2011
  • An accurate substructural synthesis method including random responses synthesis, frequency-response functions synthesis and mid-order modes synthesis is developed based on rigorous substructure description, dynamic condensation and coupling. An entire structure can firstly be divided into several substructures according to different functions, geometric and dynamic characteristics. Substructural displacements are expressed exactly by retained mid-order fixed-interfacial normal modes and residual constraint modes. Substructural interfacial degree-of-freedoms are eliminated by interfacial displacements compatibility and forces equilibrium between adjacent substructures. Then substructural mode vibration equations are coupled to form an exact-condensed synthesized structure equation, from which structural mid-order modes are calculated accurately. Furthermore, substructural frequency-response function equations are coupled to yield an exact-condensed synthesized structure vibration equation in frequency domain, from which the generalized structural frequency-response functions are obtained. Substructural frequency-response functions are calculated separately by using the generalized frequency-response functions, which can be assembled into an entire-structural frequency-response function matrix. Substructural power spectral density functions are expressed by the exact-synthesized substructural frequency-response functions, and substructural random responses such as correlation functions and mean-square responses can be calculated separately. The accuracy and capacity of the proposed substructure synthesis method is verified by numerical examples.

Modeling of non-ideal frequency response in capacitive MEMS resonator (정전 용량형 MEMS 공진기의 비이상적 주파수 응답 모델링)

  • Ko, Hyoung-Ho
    • Journal of Sensor Science and Technology
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    • v.19 no.3
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    • pp.191-196
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    • 2010
  • In this paper, modeling of the non-ideal frequency response, especially "notch-and-spike" magnitude phenomenon and phase lag distortion, are discussed. To characterize the non-ideal frequency response, a new electro-mechanical simulation model based on SPICE is proposed using the driving loop of the capacitive vibratory gyroscope. The parasitic components of the driving loop are found to be the major factors of non-ideal frequency response, and it is verified with the measurement results.

Study on Development & Implementation of Online Generator Frequency Response Test (On-line 발전기 주파수응답시험 개발 및 적용에 관한 연구)

  • Oh, Chang-Soo;Kwak, Wol-Hwan
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.48-49
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    • 2006
  • Recently, Importance of Generator's Active/Reactive Power Control Capability is highly emphasized for prevention of Large Blackout. Especially, Generator's frequency Response Capability is important to the Power System Frequency Stability. This paper deals with the Development & Implementation of Each Generator Frequency Response Capability Test via the Injection of Artificial Frequency to the Online Generator. Actual On-line Generator's frequency Response Test was successfully implemented to 13 Generator having various fuel source.

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The Effect of Load Impedances on the Frequency Response of Pressure Propagation in the Pneumatic Transmission Line (기체 전달 관로에 있어서 압력 전파의 주파수 응답에 대한 부하 임피던스의 영향)

  • Yoon, S.J.;Son, B.J.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.6 no.4
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    • pp.344-353
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    • 1994
  • This study numerically analyzed the dynamic characteristics of the frequency response on the pneumatic transmission line with load impedances. The pressure transfer function is represented by the distributed parameter line model. To validate the mathematical approximations of Bessel function ratios, the results of frequency response in a blocked line were compared with those obtained by the Infinite-product, Brown's and Square-root approximations. Special emphasis was given to the frequency response characteristics on the pneumatic transmission line with load impedances. Computations were carried out for the wide range of parameters in terms of load capacitance ratio and load resistance ratio. The present results indicated that the theoretical model is capable of accurately predicting the frequency response characteristics for any configuration of a fluid transmission line.

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The Measurement Algorithm for Microphone's Frequency Character Response Using OATSP (OATSP를 이용한 마이크로폰의 주파수 특성 응답 측정 알고리즘)

  • Park, Byoung-Uk;Kim, Hack-Yoon
    • The Journal of the Acoustical Society of Korea
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    • v.26 no.2
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    • pp.61-68
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    • 2007
  • The frequency response of a microphone, which indicates the frequency range that a microphone can output within the approved level, is one of the most significant standards used to measure the characteristics of a microphone. At present, conventional methods of measuring the frequency response are complicated and involve the use of expensive equipment. To complement the disadvantages, this paper suggests a new algorithm that can measure the frequency response of a microphone in a simple manner. The algorithm suggested in this paper generates the Optimized Aoshima's Time Stretched Pulse(OATSP) signal from a computer via a standard speaker and measures the impulse response of a microphone by convolution the inverse OATSP signal and the received by the microphone to be measured. Then, the frequency response of the microphone to be measured is calculated using the signals. The performance test for the algorithm suggested in the study was conducted through a comparative analysis of the frequency response data and the measures of frequency response of the microphone measured by the algorithm. It proved that the algorithm is suitable for measuring the frequency response of a microphone, and that despite a few errors they are all within the error tolerance.

Criteria for processing response-spectrum-compatible seismic accelerations simulated via spectral representation

  • Zerva, A.;Morikawa, H.;Sawada, S.
    • Earthquakes and Structures
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    • v.3 no.3_4
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    • pp.341-363
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    • 2012
  • The spectral representation method is a quick and versatile tool for the generation of spatially variable, response-spectrum-compatible simulations to be used in the nonlinear seismic response evaluation of extended structures, such as bridges. However, just as recorded data, these simulated accelerations require processing, but, unlike recorded data, the reasons for their processing are purely numerical. Hence, the criteria for the processing of acceleration simulations need to be tied to the effect of processing on the structural response. This paper presents a framework for processing acceleration simulations that is based on seismological approaches for processing recorded data, but establishes the corner frequency of the high-pass filter by minimizing the effect of processing on the response of the structural system, for the response evaluation of which the ground motions were generated. The proposed two-step criterion selects the filter corner frequency by considering both the dynamic and the pseudo-static response of the systems. First, it ensures that the linear/nonlinear dynamic structural response induced by the processed simulations captures the characteristics of the system's dynamic response caused by the unprocessed simulations, the frequency content of which is fully compatible with the target response spectrum. Second, it examines the adequacy of the selected estimate for the filter corner frequency by evaluating the pseudo-static response of the system subjected to spatially variable excitations. It is noted that the first step of this two-fold criterion suffices for the establishment of the corner frequency for the processing of acceleration time series generated at a single ground-surface location to be used in the seismic response evaluation of, e.g. a building structure. Furthermore, the concept also applies for the processing of acceleration time series generated by means of any approach that does not provide physical considerations for the selection of the corner frequency of the high-pass filter.

Estimation of Pump Induced Vibration Force by Frequency Response Function (진동수응답함수 측정에 따른 펌프 가진력 산정)

    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.1
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    • pp.103-112
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    • 1999
  • This is study to estimate the pump induced vibration in time and frequency domain by frequency response function between two points in case of 20Hp and 50Hp centrifugal pumps. The frequency response function has real and imaginary information of signals, and response function has also real and imaginary information. So the vibration force can be obtained from the response function and frequency response function by complex calculation. And it is compared with the theoretically estimated values and it is suggested that the amplitude of vibration with main frequency is about 10~25% of pump and motor weight, and the magnitude of unbalanced mass is about 30~60% of pump and motor weight to estimated vibration force in time domain. There are the other kinds of vibration components with different frequency values of 2~3 times of its main frequency, and these kinds of information are used to control the tuning ratio between operating frequency of pump and structural frequency of concrete slab.

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A Study on Analysis of Frequency Response with Hydraulic Circuit Analysis Module (유압 회로 해석 모듈을 이용한 주파수 응답 해석에 관한 연구)

  • 전봉근;송창섭;이용주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.581-584
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    • 1995
  • The frequency response of a electro-hydraulic servo(EHS) system is studied. The frequensy response characteristics of the EHS system obtained by linerization method, nonlinerar simulation method, and experimentation are compared ane another. It is found that the frequency response of the EHS is consistent when input signal applied is very small, but that is deviated as input signal becomes large.

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