• Title/Summary/Keyword: frequency of using

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Estimation of Fundamental Frequency Using an Instantaneous Frequency Based on the Symmetric Higher Order Differential Energy Operator (대칭구조를 갖는 일반적인 고차의 미분 에너지함수를 기반한 순간주파수를 이용한 음성의 기본주파수 추정)

  • Iem, Byeong-Gwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.12
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    • pp.2374-2379
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    • 2011
  • The fundamental frequency of the voiced speech is estimated using the instantaneous frequency based on the symmetric higher order differential energy operator. The instantaneous frequency based on the symmetric higher order energy operator shows better frequency estimation result since it is aligned to the time instance of the signal. The speech is pre-processed by a lowpass filter to remove higher frequency components. Then, it is processed by the instantaneous frequency to obtain the fundamental frequency estimates. The symmetric higher order energy operator has been used as an indicator to determine the voiced/unvoiced speech. The fundamental frequency estimates are further processed by a moving average filter to obtain the monotonically changed estimates. The obtained fundamental frequency estimates have been compared with the spectrogram of the speech to confirm its accuracy.

A Frequency Locked Loop Using a Phase Frequency Detector (위상주파수 검출기를 이용한 주파수 잠금회로)

  • Im, Pyung-Soon;Lee, Dong-Hyun;Yeom, Kyung-Whan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.7
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    • pp.540-549
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    • 2017
  • A phase frequency detector(PFD) composed of logic circuits is widely used in a phase locked loop(PLL) due to the easy implementation for integrated circuits. A frequency locked loop(FLL) removes the reference oscillator in the PLL, and the resonator serves as a reference oscillator. A frequency detector(FD) is indispensable for the FLL configuration, and a FD, which is usually composed of a mixer is used to build an FLL. In this paper, instead of FD using mixer, a FD is constructed by using 1.175 GHz resonator composed of microstrip and PFD taking the versatility of PFD into consideration. Using the designed FD, FLL oscillating at a frequency of 1.175 GHz is composed. As a result of comparison with the FLL composed of FD using mixer, it was confirmed that the proposed FLL has better phase noise performance than FLL using mixer FD with FLL bandwidth.

Study on Advanced Frequency Estimation Technique using Gain Compensation

  • Park, Chul-Won;Shin, Dong-Kwang;Kim, Chul-Hwan;Kim, Hak-Man;Kim, Yoon-Sang
    • Journal of Electrical Engineering and Technology
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    • v.6 no.4
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    • pp.439-446
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    • 2011
  • Frequency is an important operating parameter for the protection, control, and stability of a power system. Thus, it must be maintained very close to its nominal frequency. Due to the sudden change in generation and loads or faults in a power system, however, frequency deviates from its nominal value. An accurate monitoring of the power frequency is essential for optimum operation and prevention of wide area blackout. Most conventional frequency estimation schemes are based on the DFT filter. In these schemes, the gain error could cause defects when the frequency deviates from the nominal value. We present an advanced frequency estimation technique using gain compensation to enhance the DFT filter-based technique. The proposed technique can reduce the gain error caused when the frequency deviates from the nominal value. Simulation studies are performed using both the data from EMTP-RV software and the user-defined arbitrary signals to demonstrate the effectiveness of the proposed algorithm. Results show that the proposed algorithm achieves good performance under both steady state tests and dynamic conditions.

Comparisons of Estimation Methods of Instantaneous Frequency and Examples of its Application to Beam, Engine Block, and Car Door Vibration (순간 진동수 추정 방법론의 비교와 외팔보, 엔진 블록 및 자동차 문 진동에 의 적용예)

  • 박연규;김양한
    • Journal of KSNVE
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    • v.3 no.4
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    • pp.341-352
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    • 1993
  • Although a frequency analysis by FFT algorithm has been widely used in the vibration community, this approach has somewhat limited features when an analysist want to see the details of frequency trends because FFT shows only energy contents along frequencies. So the concept of instantaneous frequency that represents the dominant frequency component at each time needs to be introduced. In this paper, to get the instantaneous frequency, two methods are used. Methods using Hilbert transform and evolutionary spectrum are those. One of the problems of estimating instantaneous frequency using Hilbert transform is that it is normally very sensitive to signal to noise ratio(SNR) because of the differentiation. Moving window is applied on the estimation of instantaneous frequency, and instantaneous frequency histogram are used to handle this problem and proved to be very effective. Computer simulations for various signals have been done to understand the characteristics of instantaneous frequency. The usefulness of signal analysis using instantaneous frequency was tested by three simple experiments, which were engine experiment, beam experiment, and car door experiment. The instantaneous frequency analysis is found to be a useful technique to analyze the signals that have time varying frequencies.

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Frequency Bin Alignment Using Covariance of Power Ratio of Separated Signals in Multi-channel FD-ICA (다채널 주파수영역 독립성분분석에서 분리된 신호 전력비의 공분산을 이용한 주파수 빈 정렬)

  • Quan, Xingri;Bae, Keunsung
    • Phonetics and Speech Sciences
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    • v.6 no.3
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    • pp.149-153
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    • 2014
  • In frequency domain ICA, the frequency bin permutation problem falls off the quality of separated signals. In this paper, we propose a new algorithm to solve the frequency bin permutation problem using the covariance of power ratio of separated signals in multi-channel FD-ICA. It makes use of the continuity of the spectrum of speech signals to check if frequency bin permutation occurs in the separated signal using the power ratio of adjacent frequency bins. Experimental results have shown that the proposed method could fix the frequency bin permutation problem in the multi-channel FD-ICA.

Estimation Technique of Frequency using FIR Filter in the Power System (FIR 필터를 이용한 전력계통의 주파수 추정기법)

  • 남시복;박철원;신명철
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.50 no.3
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    • pp.101-108
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    • 2001
  • Frequency is an important operating parameter of a power system. Electric power systems sustain transient frequency swings whenever the balance between generation and load does not no longer hold. To cope with this constraints, it requires an accurate and high speedy frequency deviation estimation technique and suitable adjustment to obtain the Power system energy balance. This paper describes a digital signal processing technique for measuring the operating frequency of a power system. The fundamental frequency component of 3-phase signal is first extracted by using an algorithm based on FIR filter. The rate change of the phase angle is used for estimation. To confirm the validity of the proposed algorithm, the simulation studies carried out on a typical 154KV double T/L system by using EMTP software. Some test results are presented in the paper.

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A Study on Data Transmission Using Dual Frequency (Dual 주파수를 이용한 Data 전송에 관한 연구)

  • Lee, Jin;Park, Sung Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.6
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    • pp.398-402
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    • 2018
  • The following conclusions were obtained after analyzing the data transmission characteristics using two frequencies and studying a system that selects data with a good reception frequency as a priority data. Data transmission and reception using two frequencies were measured at -41 to -51 dBm when the frequency was normal, and data transmitted at 900 MHz was selected as priority data. When priority frequency failure occurred, the frequency reception data of the next rank was automatically adopted, and when the frequency of the next rank was disturbed, the priority frequency search was performed again. The above results show that the use of two frequencies enables more stable data transmission and transmission, and further studies should be continued to expand the transmission and reception distances.

On the Application FH/SS Using Double Indirect Frequency Synthesizer (이중 간접 주파수 합성기를 이용한 FH/SS 적용에 관한 연구)

  • 정명덕;박재홍;김영민
    • Journal of the Korea Society of Computer and Information
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    • v.4 no.1
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    • pp.76-84
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    • 1999
  • For FH/SS communication, We discussed the method of indirect frequency synthesizer in several methods. The problem of sing1e frequency synthesizer using with PLL is a varied coefficient value of damping factor in frequency hopping time, which is caused unstable frequency. So. for stable frequency synthesizer, a coefficient of damping factor must be optimized and synthesized to be removed excessive response time. In this paper, we studied FH using with double loop frequency synthesizer which takes stable frequency. We made up a simulator and had a good performance(real time speed).

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A Study on the Vibrational Characteristics of Natural Frequency with Balancing type Vibratory Conveyor Using Finite Element Methods (유한요소해석법을 이용한 평형형 진동이송기의 고유진동수 특성분석에 관한 연구)

  • Lee, Seung-Yong;Yi, Sung-Il;Kim, Chol-Ho;Choi, Yong-Jae;Choi, Woo-Chun
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.568-572
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    • 2001
  • An industrial vibratory conveyor system is devised for large-scale feeding by the low-power, using natural frequency of the system. The important thing in this system is to determine the natural frequency and to drive by it. The purpose of this study is to build up reliance on the system with changing of element parameters for vibration characteristics of balancing type vibratory conveyor by using F.E.M. modeling. For investigating the natural frequency, modal testing is performed by using impact hammer, accelerometer and LMS/Vibration Analysis System. Experimental results are compared with F.E.M results. The results of the comparisons within the errors of less than 2 percent can verify the reliability of the F.E.M. analysis of the system. Also we can verify that the characteristics of natural frequency have linearly decreased(-6%) as adding the mass($50{\sim}600kg$). We can find that controlling driving frequency is necessary for triggering the natural frequency, but natural frequency is less affected by adding the mass on the balancing weight.

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Design of Frequency Synthesizer Using VCO Multi-Phase Signals (VCO 위상신호를 이용한 주파수 합성기 설계)

  • 이준호;김선홍;김종민;박창선;김동용
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.978-981
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    • 1999
  • In this paper, an improved integer-N frequency synthesizer that can be synthesized into smaller channel space than input signal frequency is presented. The proposed frequency synthesizer also has an characteristics of fast phase locking time. The frequency synthesizer performed in the manner that it divides various outputs of different phases in VCO by means of dividers that have different control signals respectively and then add the divided signal. In order to confirm the characteristics of proposed frequency synthesizer, behavioral and SPICE simulations are performed using C-language and HSPICE respectively.

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