• 조명전기설비학회논문지
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• 제28권1호
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• pp.69-78
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• 2014

In this paper, characteristics of wireless power transfer (WPT) systems using magnetically coupled resonance scheme with relay coils are investigated and modeled. Especially, asymmetric frequency splitting characteristics in over-coupled region of WPT with relays are measured and accurately modeled. Transmitter, receiver, and relay coils are modeled with R, L, C equivalent circuits. Using these circuit models and mutual inductances between coils, a WPT system is described with a linear matrix equation. For under-coupled region, a matrix is simplified considering only mutual inductances between adjacent coils. An analytical transfer characteristic of WPT system vs. distance is extracted using an inverse matrix that is acquired by Gauss elimination method for the simplified matrix. For over-coupled region, a matrix considering mutual inductances between non-adjacent coils is used to predict a frequency splitting characteristics accurately. A 6.3MHz WPT system with relay coils is implemented and measured. An accuracy of the model is investigated by comparing the output of the model with the measured results.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.1032-1036
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• 2006

In this study, we implement the potable blood gas analyzer measuring pH, $pCO_2\;and\;pO_2$ of the arterial blood. The implemented system by this study is divided into hardware and software part and also the hardware portion is parted by mechanism and electronic circuit mit. The system program is composed of operating, washing, correcting and measuring program. And to correct the system, two-point calibration method is used, one-point calibration method is also added for more accuracy, and system program is coded. For verifying the implemented system, We examine to response property of each electrode. And evaluate accuracy of the system using standard reagent and was construed as statistical.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.26-28
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• 2005

Induction generator is the most common generator in wind energy systems because of its simplicity, ruggedness, little maintenance, price and etc. But the main drawbacks in induction generator is its need of reactive power means to build up the terminal voltage. This drawback is not an obstacle today where PWM inverters can accurately supplies the induction generator with its need from reactive power. For a insurance of three-phase induction generator requires capacitive reactance of the terminal. Most of previous work uses numerical iterative method to determine this minimum capacitor. But the numerical iteration takes long time and divergence may be occurs. In this paper is presented the design methods of the minimum self-excited capacitor required for induction generator operation. And a new formula from the equivalent circuit for stable generation operation of self-excited induction generator calculates the proper capacity to obtain the terminal voltage of the load stage. The validity of proposed design methods is confirmed by experimental and computed results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.436-437
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• 2006

In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indum-tin oxide (ITO) anodes using $O_2$ gas and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $O_2$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/Alq3/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $O_2$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The impedance spectroscopy measurement of the devices with the $O_2$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.285-287
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• 1995

In the case of driving the SLIM(Single-sided Linear Induction Motor) as the VVVF inverter, the performance of SLIM, which is a thrust, normal force and so on, varies according to a slip frequency as a function of the external load. It is impossible that the open-loop control method control the speed of a SLIM accurately. So that, this paper is proposed the speed control method of a SLIM for a automatic conveyor system with the slip frequency vector control method. To analyze the dynamic characteristics of a SLIM, the state equation is derived from the equivalent circuit of the SLIM, ignored the end effect. The slip frequency and the normal force of SLIM are constantly controlled at the steady state. The simulated results is compared with the experimental values.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.531-534
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• 2004

In Recent, it became necessary to develope the technology about electrodeless fluorescent lamp according to demand of the electodeless fluorescent lamp system that used higher efficiency and advantage of long-lifetime. Especially, in the electordeless fluorescent lamp which used H-mode, efficiency of lamp is decided from matching parameter of antena and inverter. So it is of the utmost importance to design antena and inverter Therefore, this paper used a transformer principle for efficiency rising of electrodeless fluorescent lamp and interpreted an equivalent circuit, used an impedance analyzer in order to confirm a performance enhancement of lamp along design of antenna, and confirmed parameter characteristic of R, L, C, Z, Q-factor along a change of magnetic flux density. Also, this paper confirmed a luminance characteristic of electordeless lamp along parameter change with measuring optical characteristic along a change of magnetic flux density

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3335-3343
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• 2021

The impact of gamma radiation on a commercial off the shelf microcontroller board has been investigated. Three different tests have been performed to ascertain the radiation tolerance of the device from a nuclear decommissioning deployment perspective. The first test analyses the effect of radiation on the output voltage of the on-board voltage regulator during irradiation. The second test evaluated the effect of gamma radiation on the voltage characteristics of analogue and digital inputs and outputs. The final test analyses the functionality of the microcontroller when using an external, shielded voltage regulator instead of the on-board voltage regulator. The results suggest that a series of latch-ups occurs in the microcontroller during irradiation, causing increased current drain which can damage the voltage regulator if it does not have short-circuit protection. The analogue to digital conversion functionality appears to be more sensitive to gamma radiation than digital and analogue output functionality. Using an external, shielded voltage regulator can prove beneficial when used for certain applications. The collected data suggests that detaching the voltage regulator can extend the lifespan of the platform up to approximately 350 Gy.

• 대한전자공학회논문지SD
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• 제38권8호
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• pp.54-61
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• 2001

High-bandwidth DRAM을 위해 1Gb/s의 데이터 전송률까지 동작하고 그 출력 전압 스윙이 온도와 전원 전압(VDD) 변동에 무관한 CMOS open-drain 출력 구조 회로를 설계하였다. 출력 구동 회로는 여섯 개의 binary-weighted NMOS 트랜지스터로 구성되는데, 이 여섯 개 중에서 ON시킬 current control register의 내용은 추가 호로 없이 DRAM 칩에 존재하는 auto refresh 신호를 이용하여 새롭게 수정하였다. Auto refresh 시간 구간동안 current control register를 수정하는데, 이 시간 구간동안 부궤환 (negative feedback) 동작에 의해 low level 출력 전압($V_OL$)이 저전압 밴드갭 기준전압 발생기(bandgap reference voltage generator)에 의해서 만들어진 기준전압($V_{OL.ref}$)과도 같도록 유지된다. 테스트 칩은 1Gb/s의 데이터 전송률까지 성공적으로 동작하였다. 온도 $20^{\circ}C$~$90^{\circ}C$, 전원 전압 2.25V~2.75V영역에서 최악의 경우 제안된 출력 구동 회로의 $V_{OL.ref}$와 $V_OL$의 변동은 각각 2.5%와 725%로 측정된 반면, 기존의 출력 구동 회로의 $V_OL$의 변동은 같은 온도의 전원 접압의 영역에 대해 24%로 측정되었다.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.521-527
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• 1998

An important property of the intestine is the ability to secrete fluid. The intestinal secretion is regulated by a number of substances including vasoactive intestinal peptide (VIP), ATP and different inflammatory mediators. One of the most important secretagogues is adenosine during inflammation. However, the controversy concerning the underlying mechanism of adenosine-stimulated $Cl^-$ secretion in intestinal epithelial cells still continues. To investigate the effect of adenosine on $Cl^-$ secretion and its underlying mechanism in the rabbit colon mucosa, we measured short circuit current ($I_{SC}$) under automatic voltage clamp with DVC-1000 in a modified Ussing chamber. Adenosine, when added to the basolateral side of the muocsa, increased $I_{SC}$ in a dose-dependent manner. The adenosine-stimulated $I_{SC}$ response was abolished when $Cl^-$ in the bath solution was replaced completely with gluconate. In addition, the $I_{SC}$ response was inhibited by a basolateral Na-K-Cl cotransporter blocker, bumetanide, and by apical $Cl^-$ channel blockers, dephenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenyl-propylamino)-benzoate (NPPB), glibenclamide. Amiloride, an epithelial $Na^+$ channel blocker, and 4,4-diisothiocyanato-stilbene-2,2-disulphonate (DIDS), a $Ca^{2+}-activated$ $Cl^-$ channel blocker, had no effect. In the mucosa pre-stimulated with forskolin, adenosine did not show any additive effect, whereas carbachol resulted in a synergistic potentiation of the $I_{SC}$ response. The adenosine response was inhibited by 10 ${\mu}M$ H-89, an inhibitor of protein kinase A. These results suggest that the adenosine-stimulated $I_{SC}$ response is mediated by basolateral to apical $Cl^-$ secretion through a cAMP-dependent $Cl^-$ channel. The rank order of potencies of adenosine receptor agonists was $5'-(N-ethylcarboxamino)adenosine(NECA)＞N^6-(R-phenylisopropyl)adenosine(R-$ PIA)＞2-[p-(2-carbonylethyl)-phenyl-ethylamino]-5'-N-ethylcarboxaminoadenosine(CGS21680). From the above results, it can be concluded that adenosine interacts with the $A_{2b}$ adenosine receptor in the rabbit colon mucosa and a cAMP-dependent signalling mechanism underlies the stimulation of $Cl^-$ secretion.

• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.780-786
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• 2005

This study presents a non-video, non-invasive, automatic, on-site monitoring system the system employs ultrasonic transducers to detect behavior in sows before, during and after parturition. An ultrasonic transmitting/receiving (T/R) circuit of 40 kHz was mounted above a conventional parturition bed. The T/R units use ultrasonic time-of-flight (TOF) ranging technology to measure the height of the confined sows at eight predetermined locations. From this data, three momentary postures of the sow are determined, characterized as standing-posture (SP), lateral-lying-posture (LLP) and sitting posture (STP). By examining the frequencies of position switch Stand-Up-Sequence (SUS) between standing-posture (SP), lateral-lying-posture (LLP) and sitting-posture (STP) rate can be determined for the duration of the sow' confinement. Three experimental pureblooded Landrace sows undergoing normal gestation were monitored for the duration of confinement. In agreement with common observation, the sows exhibited increased restlessness as parturition approached. Analysis of the data collected in our study showed a distinct peak in Stand-Up-Sequence (SUS, i.e. the transition from lying laterally to standing up ) and sitting-posture (STP) rate approximately 12 h prior to parturition, the observed peak being 5 to 10 times higher than observed on any other measurement day. It is concluded that the presented methodology is a robust, low-cost, lowlabor method for the continuous remote monitoring of sows and similar large animals for parturition and other behavior. It is suggested that the system could be applied to automatic prediction of sow parturition, with automatic notification of remote management personnel so human attendance at birth could reduce rates of sow and piglet mortality. The results of this study provide a good basis for enhancing automation and reducing costs in large-scale sow husbandry and have applications in the testing of various large mammals for the effects of medications, diets, genetic modifications and environmental factors.