• The Korean Journal of Zoology
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• v.32 no.3
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• pp.275-280
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• 1989

Present study examined the endogenous release of luteinizing hormone releasing hormone (LHRH) from superiused hypothalamic sBces derived from Korean native cattie (KNC). In addition, the in vitro secretory pattern of LHRH release in '(NC was compared with that in imported cattle such as Holstein cow. The median eminences (ME) of hypothalamic tissues were disseded out, sliced and quici'ly placed in ice-cold superfilsion chamber. Superhision chambers containing ME slices were maintained in a constant temperature water-bath at 37$^{\circ}C$. Effluents were colleded on ice at 10 min intervals for a 4 hr superfusion period, and kept -2$0^{\circ}C$ prior to LHRH radloimmunoassay. LHRH release was analyzed by the PULSAR algorithm. The spontaneous release of LHRH from both cows was episodic during a 4 hr superhision period. The mean LHRH release, pulse amplitude and pulse interval m KNC were 11.08 $\pm$ 1.50 pg/min/mg x 10-$^2$, 21.43 1 7.28 pg/mg x 10-$^2$, and 39.42 $\pm$ 3.08 min, which were quite similar to those observed in Holstein cows. The basic charaderistics of the LHRH pulse generator of '(NC appears important for a better understanding about the endocrine function of KNC.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.318-318
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• 2012

A graphene layer is most important materials in resent year to enhance the electrical properties of semiconductor device due to high mobility, flexibility, strong mechanical resistance and transparency[1,2]. The resistance switching memory with the graphene layer have been reported for next generation nonvolatile memory device[3,4]. Also, the graphene layer is able to improve the electrical properties of memory device because of the high mobility and current density. In this study, the resistance switching memory device with metal-oxide nano-particles embedded in polyimide layer on the graphene mono-layer were fabricated. At first, the graphene layer was deposited $SiO_2$/Si substrate by using chemical vapor deposition. Then, a biphenyl-tetracarboxylic dianhydride-phenylene diamine poly-amic-acid was spin coated on the deposited metal layer on the graphene mono-layer. Then the samples were cured at $400^{\circ}C$ for 1 hour in $N_2$ atmosphere after drying at $135^{\circ}C$ for 30 min through rapid thermal annealing. The deposition of aluminum layer with thickness of 200 nm was done by a thermal evaporator. The electrical properties of device were measured at room temperature using an HP4156a precision semiconductor parameter analyzer and an Agilent 81101A pulse generator. We will discuss the switching mechanism of memory device with metal-oxide nano-particles on the graphene mono-layer.

• Journal of the Korea Society of Computer and Information
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• v.9 no.1
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• pp.9-15
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• 2004

New WSW(Wrap Side Wall) is proposed to decrease junction electric field in this paper. WSW process is fabricated after first gate etch, followed NM1 ion implantation and deposition & etch nitride layer. New WSW structure has buffer layer to decrease electric field. Also we compared the hot carrier characteristics of WSW and conventional. Also, we design a test pattern including pulse generator, level shifter and frequency divider, so that we can evaluate AC hot carrier degradation on-chip. It came to light that the universality of the hot carrier degradation between DC and AC stress condition exists, which indicates that the device degradation comes from the same physical mechanism for both AC and DC stress. From this universality, AC lifetime under circuit operation condition can be estimated from DC hot carrier degradation characteristics.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.323-326
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• 2007

In this paper, the basic experiment, electrolytic cell design and basic manufacturing have been made to interpret the characteristics of Hydrogen-Oxygen-Gas-Generator. As for the detailed matters, the data research on basic technology on Hydrogen-Oxygen-Gas and analysis on characteristics of Hydrogen-Oxygen-Gas from basic experiment. Also the experiment of characteristics and comparative evaluation between constant current source using SCR converter from existing method and constant current source using new phase shift PWM control method converter. As results when it has injected constant DC current, we has compared Gas quantities by variable ripple frequencies using phase shift PWM control method converter. Therefore, in linear region, it has not different Gas quantities by constant DC current and by phase shift PWM control method converter. Also, it has increased Gas quantities wilder linear region when put ripple frequency at saturation region. Through, Gas quantities and input rower, it has acquired higher input power per Gas quantities at put pulse current. Therefore, when designing converter or inverter for electrolysis, which has ripple current.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.942-946
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• 2006

We simulated insulation defects of stator winding wire on high voltage generator by 5 types. 4 types have one discharge source and other one has multi discharge source by simulation. For accurate decision, measurements used to PRPD pattern to occurred partial discharge source of various types. In this research, when PRPD pattern carried out or analyzed pattern recognition of discharge source, it used to powerful tools. In this result, PRPD Pattern defined to have single discharge source of 4 types by insulation defect. When insulation defect simulated, all the defected winding have not the same result. Errors for a little different can make mistakes from a subtle distinction. The difference between internal and void discharge have magnitude of pulse amplitude of inner discharge bigger than void discharge and have a shape of bisymmetry. But void discharge has a shape of bisymmetry against maximum value on polarity respectively. In cases of slot and surface discharge, we confirmed to show similar results those other researchers. In case of multi-discharge, as a result of we could classify not perfect match with occurred patterns in single discharge eachother. In the future, we will have to recognize and classify with results of multi-discharge.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.124-129
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• 2009

Recently, PWM inverter is widely utilized for many industrial applications such as high performance drive and space vector pulse width modulation(SVPWM) inverter which has high voltage ratio and low harmonics compared to conventional PWM inverter. This paper presents the implementation on a field programmable gate array(FPGA) of a SVPWM module for a voltage source inverter. The SVPWM module consists of PWM generator, current and position sensor interface and dead time compensator. The implemented SVPWM module can be integrated with a digital signal processor(DSP) to provide a flexible and effective solution for high performance voltage source inverter and for the use of multi-motor control. The performance of SVPWM module is verified by simulation and several experimental results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.344-352
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• 2018

We herein propose a calibration method for a sampling oscilloscope. The proposed method can correct the systematic errors in the oscilloscope such as time-based distortion and impedance mismatch. In addition, it can accurately estimate the residual jitter that remains after a time-based correction and the scale factor that varies in accordance with the setting of the pulse generator. The proposed method is validated thorough the comparison and verification with the power meter, and the uncertainty of the measurement method is analyzed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.92-97
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• 2008

This is a research to apply 1310nm single-mode optical fiber to a temperature sensor. The existing study of optical fiber sensor is complicated because it was made with various equipment. To vary scattering, the variation of optical frequency is measured by using Bragg(lattice) or pulse generator and also bulk system is created by YAG laser but there were some difficulties creating experimental environment and it was a problem that the stability of measured data was low. The temperature sensor system using the suggested sBs(stimulated Brillouin scattering:sBs) from this research is much more simplified straight-line system. To improve the trust and accuracy of noises from optical frequency and unclear results, it was analysed by using Neuro-Fuzzy algorithm. we tried to get more correct data than existing system. sBs measure that optical frequency changed due to the variation of temperature. The analyzed change rate of outcome by Fuzzy theory is 1.1 MHz.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.3
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• pp.25-30
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• 2014

This paper describes the design of gate driver circuits in distributed maximum power point tracking(DMPPT) controller for photovoltaic system. For the effective DMPPT control in the existence of shadowed modules, high voltage gate driver is applied to drive the DC-DC converter in each module. Some analog blocks such as 12-b ADC, PLL, and gate driver are integrated in the SoC for DMPPT. To reduce the power consumption and to avoid the high voltage damage, a short pulse generator is added in the high side level shifter. The circuit was implemented with BCDMOS 0.35um technology and can support the maximum current of 2A and the maximum voltage of 50V.

• Journal of Advanced Navigation Technology
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• v.6 no.2
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• pp.97-103
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• 2002

A recent technology trends in synthetic aperture radar(SAR) requires the ultra high resolution performance in detecting and precisely identifying the targets. In this paper, as a technique for enhancing the radar range resolution, the wide band chirp connection algorithm is presented by stitching the several chirp modules with unit bandwidth based on the linear frequency modulated chirp signal waveform. The principles of the digital chirp signal generation and its architecture for implementation is described with the wide band chirp signal generator, modulator, and demodulator. The performance analysis for the presented algorithm is given with the simulation results.