• Title/Summary/Keyword: Pulse-Compression

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Wearing of a Whole-Body Compression Garment Can Enhance Exercise Efficiency

  • Jeon, Su-Jeong;Jung, Yu-Jin;Lee, Eun-Jae;Choi, Ji-Hye;Jung, Dongju
    • Biomedical Science Letters
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    • v.27 no.2
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    • pp.88-94
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    • 2021
  • A whole-body compression garment (WBCG) is mainly used for cosmetic purpose in Korea. Another case for wearing the WBCG would be while exercising because it allows the body to move easily. But physiological effects of wearing WBCG to the body have not been known much. To investigate whether wearing WBCG would be helpful for conducting exercises, we measured physiological criteria, which could be influenced by the compression, such as cardiovascular and pulmonary function. Twelve female college students participated in this experiment. Increase of blood pressure was monitored in all of the participants when they wore a WBCG just for 10 minutes. Pulmonary function that requires skeletal muscle contraction was decreased by wearing a WBCG. Blood pressure measured after conducting exercise became even lower when wearing a WBCG than non-wearing. Interestingly, heart pulse remained lower when wearing a WBCG than non-wearing during the whole relaxing period after the exercise. Electrocardiogram (ECG) analyses showed that such lower heart rate largely depended on extension of QT time. For that reason, physiological efficiency index (PEI) was higher for wearing WBCG. These results indicate wearing WBCG could enhance exercise efficiency by lowering heart pulse.

Development of a 20 kW pulse modulator for industrial application of pulse corona process (배가스 펄스코로나 처리공정 실험설비용 20 kW급 자기펄스압축형(MPC) 펄스 모듈레이터 개발)

  • Son, Y.G.;Jang, S.D.;Oh, J.S.;Cho, M.H.;Kim, M.H.;Han, B.W.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1781-1783
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    • 2004
  • Flue gas from fossil fuel combustion is the main source of air pollution. It is recognized that $SO_2$ and $NO_x$, (sum of NO and $NO_2$) react with $H_2O$ and $O_2$ in atmosphere and convert precursors of acid rain. Streamer corona process using pulse power is one of the effective methods to remove these gases from stack. For this, pulse generator with 160 kV of output peak voltage, 0.3 ${\mu}s$ of pulse width and 120Hz of pulse repetition rate is developed. This paper shows the pulse compression characteristics to obtain optimum parameters for basic system design.

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FUNDAMENTAL PERFORMANCE OF IMAGE CODING SCHEMES BASED ON MULTIPULSE MODEL

  • Kashiwagi, Takashi;Kobayashi, Daisuke;Koda, Hiromu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.825-829
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    • 2009
  • In this paper, we examine the fundamental performance of image coding schemes based on multipulse model. First, we introduce several kinds of pulse search methods (i.e., correlation method, pulse overlap search method and pulse amplitude optimization method) for the model. These pulse search methods are derived from auto-correlation function of impulse responses and cross-correlation function between host signals and impulse responses. Next, we explain the basic procedure of multipulse image coding scheme, which uses the above pulse search methods in order to encode the high frequency component of an original image. Finally, by means of computer simulation for some test images, we examine the PSNR(Peak Signal-to-Noise Ratio) and computational complexity of these methods.

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A EMTP Simulation of High-Voltage Pulse Transformer for Pulsed Power System (펄스파워 시스템용 고전압 펄스변압기의 EMTP 시뮬레이션)

  • Kim, Min-Soo;Lee, Hyong-Gu;Ju, Heung-Jin;Ko, Kwang-Cheol;Kan, Hyong-Bu
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1984-1986
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    • 2000
  • In pulsed-power techniques. Marx generator is generally used for the high-power device. but this generator has insulation and spatial problems. So we will suggest a pulse transformer that has a small size to generate the high voltage pulse instead of Marx generator. In this paper, Pulse duration is 4 [${\mu}s$] and the ratio of input and output voltage is 40[kV]/200[kV](step-up ratio=5). The output voltage and the process of pulse compression for pulse circuit are simulated by EMTP (Electro-Magnetic Transient Program). The secondary voltage of pulse transformer is about 200[kV] and pulse width is 4[t/s]. When the secondary winding of the pulse transformer is saturated. the pulse width is 1.25[${\mu}s$]. We selected dummy load 50[$\Omega$] for impedance matching. The pulse voltage of dummy load is 100[kV] and pulse width is 500[ns].

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Pulse Compression of an Additive-Pulse Mode-Locked CW Nd:YLF Laser by Using an Optical Fiber and a Grating Pair (광섬유와 회절격자쌍을 이용한 Additive-Pulse Mode-Locking된 CW Nd:YLF 레이저의 광펄스 압축)

  • 안승준
    • Korean Journal of Optics and Photonics
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    • v.4 no.1
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    • pp.66-72
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    • 1993
  • Additive-pulse mode-locking (APM) was performed in a $1.053{\mu}m$ cw Nd:YLF laser by coupling a nonlinear external external cavity to the main cavity. The APM pulsewidth was 4.5 ps and the average output power was 1.5 W. This APM pulse was compressed by an optical fiber and a grating pair to be as short as 210 fs with a peak power of 17 kW.

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Jamming Effect of Phase-Coded Pulse Compression Radar (위상코드 펄스압축 레이더의 재밍 효과)

  • Lim, Joong-Soo
    • Journal of Convergence for Information Technology
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    • v.9 no.5
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    • pp.125-129
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    • 2019
  • This paper describes the jamming effect of phase-coded pulse compression(PCPC) radar. Barker code radar, a typical PCPC radar, separates transmission pulses into 13 or 31 small pulses and phase modulates and transmits each pulse signal to increase radar detection efficiency and reduce the influence of jamming. Generally, when the radar is subjected to jamming, the detection distance becomes shorter and the detection error rate becomes higher. In the case of noise jamming or carrier jamming on the PCPC radar, the jamming effect is very small for no phase-coded convergence. However, the jamming effect is large in the case of synchronous jamming using the pulse-coded signal as a jamming signal with DRFM. It can be seen that the jamming effect increases when the storage time of the pulse-coded signal is prolonged. This study is considered to be useful for PCPC radar and EW jamming system design.

A Lossless Image Compression Algorithm using Adaptive DPCM (적응형 DPCM 부호화를 이용한 이미지 무손실 압축 기법)

  • Hwang, Jung-Sub;Hwang, Bo-Hyun;Yun, Jong-Ho;Choi, Myung-Ryul
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.921-922
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    • 2008
  • In this paper, we propose a lossless compression algorithm using adaptive DPCM(Differential Pulse Coded Modulation) for enhancing the compression ratio. To improve the compression efficiency, various DPCM modification algorithms have been proposed. Proposed algorithm presents 16 DPCM methods and adaptively selects the DPCM method for each block. The experimental results show that proposed DPCM algorithm has better performance on compression ratio than JPEG standard.

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Computational Study of The Pulse Waves Discharged From The Open End of a Duct (관 출구로부터 방출되는 펄스파의 수치해석적 연구)

  • Kim, H.D.;Kim, H.S.;Kweon, Y.H.;Lee, D.H.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.355-360
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    • 2001
  • This study addresses a computational work of the impulsive wave which is discharged from the open end of a pipe. An initial compression wave inside the pipe is assumed to propagate toward atmosphere. The over pressure and wave-length of the initial compression wave are changed to investigate the characteristic values of the impulsive wave. The second order total variation diminishing (TVD) scheme is employed to solve the axisymmetric, compressible, unsteady Euler equations. The relationship between the initial compression wave form and impulsive wave is characterized in terms of the peak pressure of the impulsive wave and its directivity. The results obtained show that for the initial compression wave of a large wave-length the peak pressure of the impulsive wave does not depend on the over pressure of the initial compression wave, but for the initial compression wave of a very short wave-length, like a shock wave, the peak pressure of the impulsive wave is increased with an increase in the over pressure of the initial compression wave. The directivity of the impulsive wave to the pipe axis becomes significant with a decrease in the wave-length of the initial compression wave.

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Discrimination of Multi-PD sources using wavelet 2D compression for T-F distribution of PD pulse waveform (부분방전 펄스파형의 시간-주파수분포의 웨이블렛 2D 압축기술을 이용한 복합부분방전원의 식별)

  • Lee, K.W.;Kim, M.Y.;Baik, K.S.;Kang, S.H.;Lim, K.J.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1784-1786
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    • 2004
  • PD(Partial Discharge) signal emitted from PD sources has their intrinsic features in the region of time and frequency. STFT(Short Time Fourier Transform) shows time-frequency distribution at the same time. 2-Dimensional matrices(33${\times}$77) from STFT for PD pulse signals are a good feature vectors and can be decreased in dimension by wavelet 2D data compression technique. Decreased feature vectors(13${\times}$24) were used as inputs of Back-propagation ANN(Artificial Neural Network) for discrimination of Multi-PD sources(air discharge sources(3), surface discharge(1)). They are a good feature vectors for discriminating Multi-PD sources.

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