• ETRI Journal
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• v.31 no.2
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• pp.243-245
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• 2009

A novel ultra-low-power readout circuit for a pH-sensitive ion-sensitive field-effect transistor (ISFET) is proposed. It uses an ISFET/reference FET (REFET) differential pair operating in weak-inversion and a simple current-mode metal-oxide semiconductor FET (MOSFET) translinear circuit. Simulation results verify that the circuit operates with excellent common-mode rejection ability and good linearity for a single pH range from 4 to 10, while only 4 nA is drawn from a single 1 V supply voltage.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1038-1040
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• 1993

Single phase AC to DC Boost-converter which is control led with a variable hysteretic current mode for improvent of input power factor makes high power factor possible. Power Factor correction circuit can be identified with a determination of each parameters. A simaluation and experiment result to load and parameter variation is examined.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.43-45
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• 1989

Single mode pulsed incidence dye laser which has TEMoo spatial beam pattern, near gaussian temporal shape and narrow band width(less than 500MHz) has been constructed The improved performance comes as a results of cavity length(~5cm) and definition of optical path by means of longitudinal pumping. Using 1.0X10-4M RH-6G dye, conversion efficiency was approximately 2.2% and tuning range was 548-564nm.

• Journal of Information Display
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• v.5 no.3
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• pp.14-17
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• 2004

We have developed a new type of transflective liquid crystal display (LCD) with a single cell gap and a single LC mode. In our transflective configuration, a single LC mode of a 60$^{\circ}$ twisted nematic LC was used for both transmissive and reflective applications. The measured electro-optic characteristics of our transflective LC cell agree well with numerical simulation results. Moreover, the transmittance was found to show similar behavior to the reflectance.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.8
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• pp.392-401
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• 2001

This paper presents the single-stage high power factor AC to DC converter operated in active-clamp mode. The proposed converter is added active-clamping circuit to boost-flyback single-stage power factor corrected power supply. The active-clamping circuit limits voltage spikes, recycles the energy trapped in the leakage inductance, and provides a mechanism for achieving soft switching of the electronic switches to reduce the switching loss. The auxiliary switch of active-clamping circuit uses the same control and driver circuit as the main switch to reduce the additional cost and size. To verify the performance of the proposed converter, a 100W converter has been designed. The proposed converter gives good power factor correction, low line current harmonic distortions, and tight output voltage regulation, as used unity power factor.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.4
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• pp.151-156
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• 2010

In this paper, several computer simulations are investigated to confirm the DVB-H system performance and to find proper single frequency network cell coverage. From the result, we confirm that 2K mode transmission is more robust to Doppler frequency than 8K mode. The result of this paper can be partially applied to the design the single frequency network.

• Proceedings of the KIEE Conference
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• summer
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• pp.1214-1216
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• 2004

Conventional Switched Mode Power Supplies(SMPS) with diode-capacitor rectifier have distorted input current waveform with high harmonic contents. Typically, these SMPS have a power factor lower than 0,65. To improve with this problem the power factor correction(PFC) circuit of power supplies has to be introduced. PFC circuit have tendency to be applied in new power supply designs. The input active power factor correction circuits can be implemented using either the two-stage or the single-stage approach. In this paper, the comparative analysis of power factor correction circuit using feedforward control with average current mode single-stage flyback method converter and two-stage converter which is combination of boost and flyback converter. The two prototypes of 50W were designed and tested a laboratory experimental. Also, the comparative analysis is confirmed by simulation and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.4
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• pp.263-269
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• 2008

In this paper, an interleaved boost converter (IBC) with ZVT cell using a single resonant inductor in continuous conduction mode (CCM) is proposed. The IBC with the proposed ZVT cell has advantages such as a simple circuit, reduced size and low cost by using a single resonant inductor. It is more suitable for high power applications. The proposed ZVT cell circuit and principles for the IBC are explained in detail. The validity of the IBC with proposed ZVT cell is verified through experimental results.

• Journal of Power Electronics
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• v.11 no.5
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• pp.655-661
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• 2011

This paper presents two topologies for single-stage single-phase double-buck type PFC converters, designed to operate at high power factor, near sinusoidal input currents and adjustable output voltage. Unlike the known buck type PFC topologies, in which the output voltage is always lower than the maximum input voltage, the proposed converters can operate at output voltages higher than the ac input peak voltage. A reduced number of switches on the main path of the current are another characteristic of the two proposed topologies. To shape the input line currents, a fast and robust controller based on a sliding mode approach is proposed. This active non-linear control strategy, applied to these converters allows high quality input currents. A Proportional Integral (PI) controller is adopted to regulate the output voltage of the converters. This external voltage controller modulates the amplitude of the sinusoidal input current references. The performances of the presented rectifiers are verified with experimental results.

• Composites Research
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• v.32 no.6
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• pp.382-387
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• 2019

A single frequency strain mode test, a stress relaxation mode test, and a creep test using RH-DMA were performed to investigate the effects of relative humidity and temperature on the viscous properties of PET film. The relative humidity was 10%, 30%, 50%, 70%, and 90%. The temperature was considered to be 30~95℃ for single frequency strain mode tests, 30℃ and 70℃ for stress relaxation mode test, and 5~95℃ for creep test. According to the results, higher relative humidity results in lower storage modulus and loss modulus, but the maximum value of the loss modulus is not significantly affected by changes in relative humidity and is almost constant. Relaxation modulus decreases rapidly at the beginning and becomes constant, and as the temperature increases, it is susceptible to changes in relative humidity. Strain recovery also increases rapidly at the beginning and is susceptible to changes in relative humidity as the temperature increases. In addition, as the temperature increases, the degree of increase in creep compliance increases, and as the temperature rises above the glass transfer temperature, the degree of increase becomes very large. The master curve determined by the time-temperature superposition provides the information to predict the long-term performance under operating conditions such as relative humidity and temperature.