• Title/Summary/Keyword: time-varying characteristics

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Rheological Properties of Composite Flour and Dough with Concentrated Sweet Pumpkin Powder (농축단호박 분말을 대체한 혼합분과 반죽의 특성)

  • Lee, Chan-Ho;Kim, Mun-Yong;Chun, Soon-Sil
    • Korean journal of food and cookery science
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    • v.24 no.4
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    • pp.511-516
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    • 2008
  • In this study, composite flour and dough were prepared with concentrated sweet pumpkin powder(CSPP) at varying concentrations of 3, 6, 9, 12, and 15%. The samples and a control were then compared with regards to quality characteristics, including moisture, protein, and ash contents, farinogram characteristics, amylogram characteristics, and falling number of flour and extensogram characteristics of dough, in an effort to determine the optimal ratio of CSPP in the formulation. As the CSPP content increased, the moisture and protein contents of the flour increased, whereas the ash contents decreased. With regard to the farinogram characteristics of flour, water absorption, development time, and stability decreased with increasing CSPP content, while weakness increased. The control group evidenced a significantly higher beginning temperature of gelatinization as compared to the CSPP samples. The temperature of maximum viscosity, maximum viscosity, and falling number of flour decreased with increasing CSPP content. With regard to the extensogram characteristics of dough, extensibility decreased with increasing testing time and CSPP content, whereas resistance, maximum resistance, and R/E ratio increased. In conclusion, these results show that $6{\sim}9%$ CSPP may prove very useful as a substitute for wheat flour in the production of hardroll bread, and may provide good nutritional and functional properties.

Wireless monitoring of typhoon-induced variation of dynamic characteristics of a cable-stayed bridge

  • Park, Jae-Hyung;Huynh, Thanh-Canh;Kim, Jeong-Tae
    • Wind and Structures
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    • v.20 no.2
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    • pp.293-314
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    • 2015
  • In this paper, wireless monitoring of typhoon-induced variation of dynamic characteristics of a cable-stayed bridge is presented. Firstly, cable-stayed bridge with the wireless monitoring system is described. Wireless vibration sensor nodes are utilized to measure accelerations from bridge deck and stay cables. Also, modal analysis methods are selected to extract dynamic characteristics. Secondly, dynamic responses of the cable-stayed bridge under the attack of two typhoons are analyzed by estimating relationships between wind velocity and dynamic characteristics. Wind-induced variations of deck and cable vibration responses are examined based on the field measurements under the two consecutive typhoons, Bolaven and Tembin. Finally, time-varying analyses are performed to investigate non-stationary random properties of the dynamic responses under the typhoons.

EEG Signal Prediction by using State Feedback Real-Time Recurrent Neural Network (상태피드백 실시간 회귀 신경회망을 이용한 EEG 신호 예측)

  • Kim, Taek-Soo
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.51 no.1
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    • pp.39-42
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    • 2002
  • For the purpose of modeling EEG signal which has nonstationary and nonlinear dynamic characteristics, this paper propose a state feedback real time recurrent neural network model. The state feedback real time recurrent neural network is structured to have memory structure in the state of hidden layers so that it has arbitrary dynamics and ability to deal with time-varying input through its own temporal operation. For the model test, Mackey-Glass time series is used as a nonlinear dynamic system and the model is applied to the prediction of three types of EEG, alpha wave, beta wave and epileptic EEG. Experimental results show that the performance of the proposed model is better than that of other neural network models which are compared in this paper in some view points of the converging speed in learning stage and normalized mean square error for the test data set.

Variable PID Gain Control of Winder Tension of Roll-to-Roll Printing System using Estimation of Winder-Roll Radius (롤투롤 시스템의 와인더 반경 추정을 이용한 와인더 장력의 가변 PID이득 제어)

  • Park, Jong-Chan;Jeon, Sung Woong;Nam, Ki Sang;Kim, Chung Hwan
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.4
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    • pp.755-760
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    • 2013
  • The dynamics of the winder roller of a roll-to-roll printing system for printed electronics is a time-varying system because of the variation of the winder roller radius owing to rewinding or unwinding of the web. Therefore, an adaptive control method considering the time-variant characteristics is required for precise tension control. In this study, the variable PID gain method is applied to the actual roll-to-roll system and verified by experiments for unwinder tension control. The required value of the winder roller radius for the application of the variable PID gain is estimated from the measurement of the winder tension and winder motor torque. The simulation results as well as experimental results show that the fixed PID gain control cannot stabilize the tension of the winder roller with varying winder roller radius. On the other hand, the variable PID gain method can control the tension of the winder roller regardless of the winder roller radius.

Determination of Instantaneous Frequency By Continuous Wavelets Ridge (연속 웨이브렛 Ridge를 이용한 순간주파수 결정)

  • Kim, Tae-Hyung;Yoon, Dong-Han
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.1
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    • pp.8-15
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    • 2005
  • The analysis of Rader signal that have non-linearity variable phase is signal that contact easily in several fields such as radar, telecommunication, seismic, sonar and biomedical applications. In generally, Non-stationary signal means that spectral characteristics are varying with time and instantaneous frequency is only one frequency or narrow range of frequencies varying as a function of time. Therefore, Instantaneous frequency is vary important variable that understanding physical characteristic of signal. This paper was describes continuous wavelet transform to determine instantaneous frequency at non-staionary signal and compare to existing method. When white noise or various frequency is overlapped each other in sign, existing method was can not decide corrected instantaneous frequency, but when used continuous wavelet transform, very well decide correctly frequency regardless of component of signal.

A Six-Phase CRIM Driving CVT using Blend Modified Recurrent Gegenbauer OPNN Control

  • Lin, Chih-Hong
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1438-1454
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    • 2016
  • Because the nonlinear and time-varying characteristics of continuously variable transmission (CVT) systems driven by means of a six-phase copper rotor induction motor (CRIM) are unconscious, the control performance obtained for classical linear controllers is disappointing, when compared to more complex, nonlinear control methods. A blend modified recurrent Gegenbauer orthogonal polynomial neural network (OPNN) control system which has the online learning capability to come back to a nonlinear time-varying system, was complied to overcome difficulty in the design of a linear controller for six-phase CRIM driving CVT systems with lumped nonlinear load disturbances. The blend modified recurrent Gegenbauer OPNN control system can carry out examiner control, modified recurrent Gegenbauer OPNN control, and reimbursed control. Additionally, the adaptation law of the online parameters in the modified recurrent Gegenbauer OPNN is established on the Lyapunov stability theorem. The use of an amended artificial bee colony (ABC) optimization technique brought about two optimal learning rates for the parameters, which helped reform convergence. Finally, a comparison of the experimental results of the present study with those of previous studies demonstrates the high control performance of the proposed control scheme.

A Methodology of Finding the Direction of Lightning Discharge using Loop-type Magnetic Field Sensors (루프형 자계센서를 이용하여 뇌방전이 발생한 방향을 탐지하는 기법)

  • Lee, Bok-Hee;Cho, Chi-Youn;Cho, Sung-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.28 no.10
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    • pp.63-68
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    • 2014
  • This paper deals with a methodology that applies the time-varying magnetic fields produced by the cloud discharges to find the direction of thunderstorm movement. We investigated the basic performance of the magnetic field measurement system composed of multi-turn loop-type sensors, the differential amplifier and active integrator. As a result, the response characteristics of the magnetic field sensor system to sinusoidal signals was excellent. The frequency bandwidth ranges from about 1 kHz to 500 kHz, the response sensitivity was 0.16mV/nT. In addition, we proposed the algorithm that determines the direction of lightning discharges using the comparison of the output signals of right-angled loop-type magnetic field sensors. The accuracy of the direction finding of lightning discharges is fairly well within the measurement error of less than $5^{\circ}$. The magnetic field measurement system proposed in this work can be used to track the direction of thunderstorm movement.

Treatment of Bone Repair by Inductively Magnetic Fields

  • Ahn, Jae-Mok;Lee, Woo-Cheol;Kim, Hee-Chan;Min, Byoung-Goo
    • Proceedings of the KOSOMBE Conference
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    • v.1992 no.05
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    • pp.213-217
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    • 1992
  • An inductively coupled magnetical signal (pulse wave, 0.7 to 60Hz, eighteen volts peak to Peak) that was applied non-invasively on the skin surface overlying the approximate site(measure position). In the group with unipolar pulse signal currents produced smaller than in the group with bipolar pulse signal. The signal was transmitted to the active coil, including a time-varying magnetic field: this in turn induced a the-varying electrical field in the field in the bone. It is very important to determine system parameters due to treatment time(healing) and the simplicity. This paper investigation was designed to compare the relative effects of pulsed unipolar currents with the effects of an identical pulsed bipolar currents. Since Inductive coupling is non-invasive and involves portable equipment, it is easy to apply and requires precise localization, it has distinct advantages and field characteristics along the bone for each different signal.

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Electrochemical Characteristics of $LiCoO_2$+Activated Carbon Electrode for Supercapacitor (Supercapacitor용 $LiCoO_2$+Activated Carbon 전극의 전기화학적 특성)

  • Jeon, Min-Je;Kim, Ick-Jun;Lee, Sun-Young;Kim, Hyun-Su;Im, Young-Tek;Le, Sang-Hyun;Lee, Moon-Bae;Oh, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.336-337
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    • 2005
  • This study shows the effect of addition of $LiCoO_2$, with different milling time ranging from 0, 30, 200 hours, to the activated carbon electrode. Test cells consisting of activated carbon (100-X%) and $LiCoO_2$ (X%)were made (where X=10, 20, and 40). Test cells with varying concentrations of $LiCoO_2$ which differ in the milling time showed improved specific capacity compare with the cells fabricated using activated carbon alone. The enhanced capacity may be caused due to the addition of $LiCoO_2$ powders at varying concentration. An improved ESR value obtained may be caused by the smaller particle size of $LiCoO_2$. It was concluded that finer the particle size higher will be the efficiency.

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Numerical investigation on the performance of the aluminized HMX with varying aluminum concentration (알루미늄 함유량 변화에 따른 알루미늄 입자가 함유된 HMX 성능에 관한 수치 연구)

  • Kim, Wuhyun;Gwak, Min-cheol;Yoh, Jai-ick
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.617-621
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    • 2017
  • The performance characteristics of aluminized high explosive are considered by varying the aluminum(Al) concentration in a two-phase model. Since the time scales of the characteristic combustion process of high explosives and Al particles differ, the process of energy release behind the leading detonation wave front occurs over an extended period of time. Two cardinal observations are reported: a decrease in detonation velocity with an increase in Al concentration and a double front detonation (DFD) feature when anaerobic Al reaction occurs behind the front. In the current study, a series of confined rate sticks are considered for characterizing the performance of aluminized HMX with a maximum Al concentration of 50%. The simulated results are compared with the experimental data for 5%-25% concentrations.

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