• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.281-284
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• 1997

In this paper, the eddy current flow meter with 4-coil group is designed and made on the basis of theory, and its characteristics is considered through dry test flow experiments. The biggest output signal varied with wave form and frequency, and 900Hz in rectangular wave, 27.12kHz in sine wave. The conductivity is bigger, the output signal is bigger and has a linearity between both relation, and also The Magnetic Reynolds Number and output characteristics. The flow faster and the output singnal is bigger.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.350-356
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• 2006

In this study, piezoelectric transformer was manufactured at the sintering temperature of $950^{\circ}C$, and then the feasibility of application to low temperature sintering piezoelectric transformers was investigated by evaluating the electrical characteristics of it. The voltage ratio of piezoelectric transformer showed the maximum value at the resonant frequency of input part, and increased according to the increase of load resistance. The output power and efficiency of piezoelectric transformer showed the superior properties when the output impedance of it coincides with the load resistance. Piezoelectric transformer manufactured at the low temperature of $950^{\circ}C$ showed the heat generation less than $20^{\circ}C$ at the output power of 30 W, and stable driving characteristics.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.28A no.10
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• pp.806-813
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• 1991

In this paper, we suggested the diagnosis of the optical FSK transmitter output characteristics using the Micheloson interferometer. The transmitter is designed by the direct frequency modulation effect of a semoconductor laser diode. The optical FSK transmitter consists of a temperature stabilized semiconductor laser diode and an optimally designed equalizer. It is modulated by 100Mbit/s PRBS Generator to diagonosis of Optical FSK transmitter output characteristics. The Michelson Interferometer is used for the optical frequency discriminator which transforms the output frequency of the transmitter to the amplitude of light. The measurement of the performance of the transmitter to the amplitude of light. The measurement of the performance of the transmitter computer the transmitted data and their eye pattern with the simulation results, the received data and their eye pattern. As the result of experiment, the data transfer rate of the transmitters is 100Mbit/s.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1722-1727
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• 1992

In this study, techniques of adaptive input-output linearizing control of a class of uncertain nonlinear system are investigated. It is shown through concepts of signal growth rates that bounded trackings yield by adaptive input-output linearizing control law using normalized estimator. The convergence characteristics are improved significantly by using the normalized estimator. Simple example is presented as illustration.

• Electrical & Electronic Materials
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• v.10 no.10
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• pp.1022-1028
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• 1997

In this paper we present the construction details and output characteristics of a diaphragm-type pressure sensor with Cu-Ni(53:47) thin-film strain gauges. In order to improve the sensitivity and the temperature compensation two circumferential gauges are placed near the center of the diaphragm and two radial gauges are located near the edge. For all the gauges the relative change in resistance ΔR/R with pressure is of the order 10$^{-3}$ for the maximum pressure. The output is found to be linear over the entire pressure range(0-30kfg/cm$^2$)and the output sensitivity obtained is 1.6mV/V. The maximum nonlinearity observed in output characteristics is 0.35%FS for 5V excitation and the hysteresis is less than 0.1%FS.

• Korean Journal of Optics and Photonics
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• v.19 no.1
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• pp.43-47
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• 2008

Nowadays, the pattern size of BLU (Back Light Unit) adopted in TFT-LCD (Thin Film Transistor Liquid Crystal Display) is typically a few tens of micrometers. However, recently, researches on the TFT-LCD output characteristics depending on various types of BLU patterns are being performed in order to improve the output and uniformity. In this study, we analyzed the influence of pattern size, distribution, and areal ratio on the output characteristics.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.1096-1099
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• 1996

In this paper, the eddy current flowmeter with 4-coil is designed and made on the basis of theory, and its characteristics is considered through dry test and flow experiments. The biggest output signal varied with wave wave form frequency, and 900Hz in rectangular wave, 27.12kHz in sine wave. The conductivity is bigger, the output signal is bigger and has a linearity between both relation, and also The Magnetic Reynolds Number and output characteristics The flow faster and the output signal is bigger.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.142-151
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• 2020

This paper presents a DC/DC LLC resonant converter with wide input/output voltage gain characteristics and its control method for efficiency improvement. For a wide input/output voltage gain characteristics without designing small transformer magnetization inductance, the proposed converter changes the topology into three modes of operation according to the main switch switching pattern. In each operating mode, variable LINK voltage modulation and frequency modulation were performed to control output voltage and improve operating efficiency. A prototype of a 5-kW DC/DC LLC resonant converter was built and tested to verify the validity and applicability of the proposed converter.

• Nuclear Engineering and Technology
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• v.52 no.12
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• pp.2743-2759
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• 2020

A detailed computational fluid dynamics (CFD) simulation analysis model was developed using ANSYS CFX 16.1 and analyzed to simulate the basic design and internal flow characteristics of a 180 MW small modular reactor (SMR) with a natural circulation flow system. To analyze the natural circulation phenomena without a pump for the initial flow generation inside the reactor, the flow characteristics were evaluated for each output assuming various initial powers relative to the critical condition. The eddy phenomenon and the flow imbalance phenomenon at each output were confirmed, and a flow leveling structure under the core was proposed for an optimization of the internal natural circulation flow. In the steady-state analysis, the temperature distribution and heat transfer speed at each position considering an increase in the output power of the core were calculated, and the conceptual design of the SMR had a sufficient thermal margin (31.4 K). A transient model with the output ranging from 0% to 100% was analyzed, and the obtained values were close to the T_hot and T_cold temperature difference value estimated in the conceptual design of the SMR. The K-factor was calculated from the flow analysis data of the CFX model and applied to an analysis model in RELAP5/MOD3.3, the optimal analysis system code for nuclear power plants. The CFX analysis results and RELAP analysis results were evaluated in terms of the internal flow characteristics per core output. The two codes, which model the same nuclear power plant, have different flow analysis schemes but can be used complementarily. In particular, it will be useful to carry out detailed studies of the timing of the steam generator intervention when an SMR is activated. The thermal and hydraulic characteristics of the models that applied porous media to the core & steam generators and the models that embodied the entire detail shape were compared and analyzed. Although there were differences in the ability to analyze detailed flow characteristics at some low powers, it was confirmed that there was no significant difference in the thermal hydraulic characteristics' analysis of the SMR system's conceptual design.

• Journal of the Optical Society of Korea
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• v.2 no.2
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• pp.64-73
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• 1998

We have theoretically analyzed and experimentally observed the effects of wavelength dependent birefringence inside a laser cavity on the output characteristics of fiber lasers with a figure eight geometry. The spectral and polarization characteristics of fiber lasers are found to be very susceptible to the resultant birefringence composed of the intrinsically existing wavelength dependent birefringence and the externally induced birefringences inside the fiber. For the variation of twist-induced birefringence inside the nonlinear amplifying loop mirror, the laser output power and center wave-length of continuous wave lasers change periodically, but the polarization characteristics remains nearly unchanged. The changes of the birefringence inside the linear loop has little effect on the spectral characteristics but changes the polarization properties such as the polarization direction.