• Title/Summary/Keyword: Electrical response

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The Effects of Nerve Growth Factor Expression of Central Nerve System by Environmental Enrichment and Peripheral Nerve Electrical Stimulation in Brain Ischemia Model Rats (뇌졸중 유발 백서모델에서 환경강화와 말초신경전기자극이 중추신경계의 신경성장인자에 미치는 영향)

  • Kim, Sa-Youl;Kim, Eun-Jung;Kim, Gye-Yeop
    • The Journal of Korean Physical Therapy
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    • v.19 no.4
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    • pp.33-41
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    • 2007
  • Purpose: To investigate environmental enrichment and nerve stimulation follows in application times with the change of BDNF & Trk-B receptor in the motor cortex and spinal cord. Methods: Experimental groups were divided into the five groups. Group I: normal control group, Group II: experiment control group, Group III: sciatic never electrical stimulation after MCAO, Group IV: application of only environmental enrichment after MCAO, Group V: never electrical stimulation with environmental enrichment after MCAO. Histologic observation and coronal sections were processed individually in goat polyclonal antibody phosphorylated BDNF and rabbit polyclonal antibody Trk-B receptor. Results: In immunohistochemistric response of BDNF and Trk-B, group II were showed that lower response effect at postischemic 1 days, 3 days, and 7 days. Group V were showed that increase response effect at postischemic 3 days, 7 days and 14 days. Specially showed that the most response effect at postischemic 14 days. In neurobehavioral assessment, group V were significantly difference from other groups on between-subject effects. Conclusion: The above results suggest that combined environmental enrichment with peripheral nerve electrical stimulation in focal ischemic brain injury were more improved that the change of BDNF & Trk-B receptor expression than non treatment.

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Effect of R-C Compensation on Switching Regulation of CMOS Low Dropout Regulator

  • Choi, Ikguen;Jeong, Hyeim;Yu, Junho;Kim, Namsoo
    • Transactions on Electrical and Electronic Materials
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    • v.17 no.3
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    • pp.172-177
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    • 2016
  • Miller feedback compensation is introduced in a low dropout regulator (LDO) in order to obtain a capacitor-free regulator and improve the fast transient response. The conventional LDO has a limited bandwidth because of the large-size output capacitor and parasitic gate capacitance in the power MOSFET. In order to obtain a stable frequency response without the output capacitor, LDO is designed with resistor-capacitor (R-C) compensation and this is achieved with a connection between the gain-stage and the power MOS. An R-C compensator is suggested to provide a pole and zero to improve the stability. The proposed LDO is designed with the 0.35 μm CMOS process. Simulation testing shows that the phase margin in the Bode plot indicates a stable response, which is over 100o. In the load regulation, the transient time is within 55 μs when the load current changes from 0.1 to 1 mA.

A Study on the Sensor for Measuring the High Frequency Magnetic Fields (고주파자계측정용 센서에 관한 연구)

  • Lee, Bok-Hee;Jeong, Seung-Soo;Park, Hyung-Ki;Paek, Yong-Hyun;Yim, Dong-Mook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.114-117
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    • 1992
  • This paper presents the design and calibration methods of self-integrated magnetic sensor. Also the distance response measurement of magnetic field produced a transient large current and the frequency response measurement are carried out As the integrating resistance increases. the sensitivity of the sensor is improved, but the decay time constant of response decreases, Also the experimental results are well agreed with the theoretical analysis of the equivalent circuit.

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Electrochemical Detection of Self-Assembled Viologen Modified Electrode as Mediator of Glucose Sensor

  • Lee, Dong-Yun;Choi, Won-Suk;Park, Sang-Hyun;Kwon, Young-Soo
    • Journal of Electrical Engineering and Technology
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    • v.4 no.1
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    • pp.106-110
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    • 2009
  • An amperometric glucose biosensor has been developed using viologen derivatives as a charge transfer mediator between a glucose oxidase (GOD) and a gold electrode. A highly stable self-assembled monolayer (SAM) of thiol-based viologen was immobilized onto the gold electrode of a quartz crystal microbalance (QCM) and GOD was immobilized onto the viologen modified electrode. This biosensor response to glucose was evaluated amperometrically in the potential of -300mV. Upon immobilization of the glucose oxidase onto the viologen modified electrode, the biosensor showed rapid response towards glucose. Experimental conditions influencing the biosensor performance, such as pH potential, were optimized and assessed. This biosensor offered excellent electrochemical responses for glucose concentration below ${\mu}$ mol level with high sensitivity and selectivity and short response time. The levels of the RSDs (<5%) for the entire analyses reflected the highly reproducible sensor performance. A linear calibration range between the current and the glucose concentration was obtained up to $4.5{\times}10^{-4}M$. The detection limit was determined to be $3.0{\times}10^{-6}M$.

Electrical Properties of Multilayer Chip Varistors in the Response Surface Analysis (반응표면분석법에 의한 적층 칩 바리스터의 전기적 특성)

  • Yoon, Jung-Rag;Jeong, Tae-Seok;Choi, Keun-Mook;Lee, Seok-Weon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.20 no.6
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    • pp.496-501
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    • 2007
  • In order to enhance sintering characteristics on the $ZnO-Pr_6O_{11}$ based multilayer chip varistors (MLVs), a response surface analysis using central composite design method were carried out. As a result, varistor voltage($V_{1mA}$), nonlinear coefficient ($\alpha$), leakage current ($I_L$) and capacitance (C) were considered to be mainly affected by sintered temperature and holding time. MLVs sintered at $1200^{\circ}C$ and above $1200^{\circ}C$ revealed poor electrical characteristics, possibly due to the reaction between electrode materials(Pd) and $ZnO-Pr_6O_{11}$ based ceramics. On the sintering temperature range $1150{\sim}1175^{\circ}C$, nonlinear coefficient ($\alpha$) and leakage current ($I_L$) were shown to be $60{\sim}69$ and below $0.3{\mu}A$, respectively. In particular, MLVs sintered at $1175^{\circ}C$, 1.5 hr and $2^{\circ}C/hr$ (cooling speed) showed stable ESD(Electrical Static Discharge) characteristics under the condition of 10 times at 8 Kv with deviation varistor voltage, and deviation nonlinear coefficient were 0.3% and 0.33% (at positive), 0.55% (at negative), respectively.

Vibration Response of a Human Carpal Muscle (인체 수관절 근육의 진동 응답)

  • Chun, Han-Yong;Kim, Jin-Oh;Park, Kwang-Hun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.1
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    • pp.31-40
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    • 2011
  • This paper examines the dynamic characteristics of a human carpal muscle through theoretical analysis and experiment. The carpal muscle was modeled as a 1-DOF vibration system and vibration response due to a ramp function force was calculated. The electromyogram signal corresponding to the muscle excitation force was measured, and the excitation force function of an envelope curve from the electromyogram signal was extracted. The ramp input function of electrical stimulation to the carpal muscle was applied by using a device for functional electrical stimulation, and the angular displacements corresponding to steady state response were measured. Theoretical calculations of the vibration response displacements were compared with the experimental results of the angular displacements, and have shown a good agreement with the result that is linearly proportional to the excitation force magnitude. As a result, the relationship between the input current of the electrical stimulation and the excitation force magnitude was inferred. The result was shown that it can be applied to develop rehabilitation training devices.

Economic Evaluation of ESS Applying to Demand Response Management in Urban Railway System (도시철도부하 수요자원 관리에 ESS 활용 시 경제성 분석)

  • Park, Jong-young;Heo, Jae-Haeng;Kim, Hyeongig;Kim, Hyungchul;Shin, Seungkwon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.1
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    • pp.222-228
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    • 2017
  • The aims of the demand response market are stabilization of the power supply and improving of the reliability of the power system. The various applications of the energy storage system (ESS) in the railway systems are studied and implemented to raise the energy efficiency. It is one of the most important how to determine the obligation reduction capacity (ORC) in participation to the demand response market because it has an influence on the profit extremely. In this paper, when participating to the demand response market with demands in the urban railway, we calculated the available ORC and economically evaluated ESS based on the real load data.

Robust FIR filter for Linear Discrete-time System

  • Quan, Zhong-Hua;Han, Soo-Hee;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2548-2551
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    • 2005
  • In this paper, a robust receding horizon finite impulse response(FIR) filter is proposed for a class of linear discrete time systems with uncertainty satisfying an integral quadratic constraint. The robust state estimation problem involves constructing the set of all possible states at the current time consistent with given system input, output measurements and the integral quadratic constraint.

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Transient Characteristics Analysis of Superconducting Alternator with Slitted Electrothermal Shield (틈새를 낸 열전자 차폐막을 갖는 초전도 교류 발전기의 과도특성 해석)

  • Hahn, Sung-Chin;Hahn, Song-Yop
    • Proceedings of the KIEE Conference
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    • 1993.11a
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    • pp.73-75
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    • 1993
  • In this paper, the transient shielding characteristics of slitted electrothermal shield of superconducting alternator is studied. The field current and the armature currents variations during three phase short circuit fault are calculated and compared to those of the conventional one. And the response of the armature current due to step-up of the excitation voltage showes the feasibility of the quick response excitation system available for improving the transient stability.

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Frequency Response Characteristics by Using Tone-Burst Method for Piezoelectric Ceramic Transducer (압전 세라믹 트랜스듀서의 Tone-Burst법에 의한 주파수 응답특성)

  • Bae, Hyo-Yoon;SaGong, Geon
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.806-809
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    • 1988
  • The frequency response characteristics of a bimorph type PZT piezoelectric transducer was investigated. In this study, function generator which generates short burst signal, plane reflection plate and oscilloscope were used to measure the characteristics of piezoceramic ultrasonic transducer. The resonant frequency of a bimorph type piezoceramic transducer which is acquired by using Tone-Burst Method had good agreement with the measured results from spectrum analyzer.

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