• 제목/요약/키워드: normalized k

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A Composite LMMSE Channel Estimator for Spectrum-Efficient OFDM Transmit Diversity

  • Seo, Jeong-Wook;Jeon, Won-Gi;Paik, Jong-Ho;Jo, Min-Ho;Kim, Dong-Ku
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.2 no.4
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    • pp.209-221
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    • 2008
  • In this paper, we propose a subcarrier allocation method and a composite linear minimum mean square error (LMMSE) channel estimator to increase spectrum efficiency in orthogonal frequency division multiplexing (OFDM) transmit diversity. The pilot symbols for OFDM transmit (Alamouti) diversity are exclusively allocated in two OFDM symbols in different antennas, which causes serious degradation of spectrum efficiency. To reduce the number of pilot symbols, our subcarrier allocation method uses repetition-coded data symbols, and the proposed channel estimator maintains good bit error rate (BER) performance.

Implementation of 4 Channel Photo-Plethysmogram System(I) (4 채널의 Photo-plethysmogram 시스템 구현에 관한 연구(I))

  • Kim, Hyoung-Tae;Han, Soon-Chen;Kim, Jung-Kuk;Huh, Woong;Park, Young-Bae
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.253-256
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    • 2002
  • In this paper, we implement the volume pulse detection system which can quantitatively represent an artery elasticity. The system consists of transducer which has IRLED-photodiode detecter, temperature sensor, filters, preprocessing circuits, A/D converter, serial communication part and computer system. In order to presume the artery elasticity information we measure the volume pulse at four points and then evaluate the transition time, distance and the correlation coefficient of the pulse wave between the points. We test the system with 10 subjects during the week for basic experiment and obtain the data at four points. As the result of experiment, we can detect normalized volume pulse wave and evaluated parameter with effectively.

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Nonlinear identification of Bouc-Wen hysteretic parameters using improved experience-based learning algorithm

  • Luo, Weili;Zheng, Tongyi;Tong, Huawei;Zhou, Yun;Lu, Zhongrong
    • Structural Engineering and Mechanics
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    • v.76 no.1
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    • pp.101-114
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    • 2020
  • In this paper, an improved experience-based learning algorithm (EBL), termed as IEBL, is proposed to solve the nonlinear hysteretic parameter identification problem with Bouc-Wen model. A quasi-opposition-based learning mechanism and new updating equations are introduced to improve both the exploration and exploitation abilities of the algorithm. Numerical studies on a single-degree-of-freedom system without/with viscous damping are conducted to investigate the efficiency and robustness of the proposed algorithm. A laboratory test of seven lead-filled steel tube dampers is presented and their hysteretic parameters are also successfully identified with normalized mean square error values less than 2.97%. Both numerical and laboratory results confirm that, in comparison with EBL, CMFOA, SSA, and Jaya, the IEBL is superior in nonlinear hysteretic parameter identification in terms of convergence and accuracy even under measurement noise.

A Characteristic Analysis of Instantaneous Resonance Voltage Resultant Type DC-DC Converter (순시 공진 전압 합성형 DC-DC 컨버터의 특성해석)

  • Hwang, Gye-Ho;Oh, Kyeong-Seob;Ro, Chae-Gyun;Nam, Seung-Sik;Min, Byeong-Jae;Kim, Kyeong-Sik
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2033-2035
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    • 1998
  • This paper describes a DC-DC converter connected two unites inverters, a half-bridge type of high frequency resonance inverter, at the input with parallel. The proposed paper certified that theorem waveforms are equal to experiment waveforms, in addition, it estimated characteristics such as characteristic of average power, characteristic of average output voltage, characterisic of output voltage ripple etc., for designing the device with normalized parameter value.

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Current tracking Control type Inverter using Neural Network (신경 회로망을 이용한 전류 추종 제어형 인버터)

  • Kim, Jong-Hae;Sim, Kwang-Yeal;Bae, Sang-June;Kim, Dong-Hee;Lee, Dal-Hae
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.252-254
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    • 1994
  • This paper describes the control method in order that output current of a voltage source inverter tracks reference sinusoidal current so that its harmonic current components are reduced. Operating character of this inverter is analyzed with normalized values of parameter. And the method that apply multilayed feedfoeward neural networks, which play excellent steady state operation in control system, to inverter control system and training method are presented. Then, the output current of inverter which is driven by the proposed method. is considered throughout computer simulation and safe operating range of inverter parameter is resented.

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Characteristic Analysis of Series Resonant High Frequency Inverter with Separated Capacitor (커패시터 분할형을 갖는 직렬공진 고주파 인버터의 특성해석)

  • Lee, Bong-Seob;Oh, Seung-Hoon;Jung, Do-Young;Lee, Sang-Ho;Ko, Seo-Yeong;Oh, Hong-Seok
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1224-1226
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    • 2000
  • In this paper, load paralleled type FB series resonant inverter of a new novel type is proposed. In the output control method, phase-shift driving signal control method with CVCF introduces. Also by driving signal patterns, the operation principle of the proposed circuit in detail is described and its characteristics are compared on separated ratio(n). According to each the mode in order to the analysis and characteristic evaluation of the circuit state equations are derived and presented using normalized parameter. To verify the theoretical analysis result, experimental results are provided.

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Evolution Properties of a Partially Coherent Flat-topped Vortex Hollow Beam Propagating in Uniaxial Crystals Orthogonal to the Optical Axis

  • Liu, Dajun;Wang, Guiqiu;Luo, Xixian;Yin, Hongming;Wang, Yaochuan
    • Journal of the Optical Society of Korea
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    • v.20 no.6
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    • pp.686-693
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    • 2016
  • The analytical expressions for a partially coherent flat-topped vortex hollow beam propagating in uniaxial crystals orthogonal to the optical axis are derived, and the intensity and coherent vortex properties of partially coherent flat-topped vortex hollow beam propagation in uniaxial crystals orthogonal to the optical axis are analyzed by numerical examples. The influence of beam order parameter N, topological charge M, the coherence length and the ratio of refractive indices $n_e/n_o$ of uniaxial crystals on the normalized intensity distribution and coherent vortex of a partially coherent flat-topped vortex hollow beam propagating in uniaxial crystals are discussed in detail.

Ventricular Tachycardia Imitating Epileptic Seizures (뇌전증발작 양상을 보인 심실 빈맥)

  • Park, Min-Ho;Won, Hye-Yeon;Im, Dong-Gyu;Byeon, Kyoung-Min;Heo, Jae-Hyeok
    • Annals of Clinical Neurophysiology
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    • v.17 no.2
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    • pp.80-81
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    • 2015
  • Syncopes are the most common non-epileptic attacks mimicking epileptic seizures. Among them, cardiogenic syncope is potentially life threatening. A 49 year old man was refered for the recurrent episodes of loss of consciousness with tonic posture and upward eyes deviation. The electrocardiogram showed polymorphologic ventricular tachycardia during attacks, which normalized after that. He was treated with isoproterenol and symptoms subsided. Here, we report a case of ventricular tachycardia manifested as epileptic seizures.

Transport current loss of YBCO Coated Conductor and Bi-2223 tape (Bi-2223 선재와 YBCO Coated Conductor 선재의 전송전류 손실 비교)

  • Lim Hyoungwoo;Lee Kwangyoun;Cha Gueesoo;Lee Jikwang;Park Chan
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.1010-1012
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    • 2004
  • AC loss is an important factor in the development of superconducting tapes and superconducting power applications. In this paper we measured and compared characteristics of BSCCO tape and YBCO Coated Conductor(YBCO CC). BSCCO tape was fabricated by PIT method. We measured critical current density and transport current loss of it. Also, YBCO CC tape consist of substrate. buffer, YBCO and metal layers. We measured critical current density on variations of external magnetic field and transport current loss of these cases. The results of measurement show that normalized critical current of YBCO CC is smaller then that of BSCCO tape in the external magnet field. According to the results. measured loss and calculated of the YBCO CC show the same tendency.

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A study on analysis of characteristics of Current-fed type High-Frequency Inverter with separate resonance capacitor (분할 공진 Capacitor를 갖는 전류형 고주파 인버어터의 특성해석에 관한 연구)

  • Lee, Bong-Seop;Ro, Chae-Cyun;Jung, Won-Yeung;Kim, Dong-Hee
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.704-706
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    • 1993
  • This paper, introduces a Current-fed type High-Frequency Inverter with self turning devices. By replacing Thyrisors used for power source of heat treatment with high speed switching element, MOSFET in current type Inverter, the proposed Inverter makes high speed performance with several 100kHz. This paper also depicts some operating principles of the proposed circuits and general operating characteristics. Steady state solution on state variables in analysis of the proposed circuit is described generally by using normalized parameter and its characteristics depending on separate ratio(n) is also shown.

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