• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.216-219
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• 2000

A Ka Band 3-stage MMIC (Monolithic Microwave Integrated Circuits) LNA(Low Noise Amplifiers) has been designed. The MMIC LNA consists of two single-ended type amplication stapes and one balanced type amplication stage to satisfy noise figure characteristics and high gain and amplitude linearity. The 0.15um pHEMT has been used to provide a ultra low noise figure and high gain amplification. Series and Shunt feedback circuits were inserted to ensure high stability over frequency range of DC to 80 GHz. The size of designed MMIC LNA is 3100mm ${\times}$ 2400um(7.44$\textrm{mm}^2$). The on wafer measured noise figure of the MMIC LNA is less than 2.0 dB over frequency range of 22 GHz to 30 GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.11-15
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• 2002

3 V, 2.46GHz Low Noise Amplifier (LNA) have been designed for standard 0.35$\mu\textrm{m}$ CMOS process with one poly and four metal layers. This design includes on-chip biasing, matching network and multilayer spiral inductors. The single-ended amplifier provides a forward gain of 20.5dB with a noise figure 3.35dB, and an IIP3 of -6dBm while drawing 59mW total Power consumption

• JSTS:Journal of Semiconductor Technology and Science
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• v.7 no.4
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• pp.235-240
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• 2007

A current-balancing segmented group-inverting transmitter is presented for multi-Gb/s single-ended parallel links. With an additional increase of 4 pins, 16-bit data is efficiently encoded to 20 pins to achieve the current balancing and eliminate the simultaneous switching noise. Since the proposed coding is a simple inversion-or-not transformation of pre-defined groups of binary data, it can be implemented with simplified logic circuits. The transmitter is designed with a $0.18{\mu}m$ CMOS technology, and simulated eye diagrams at 5Gb/s show dramatic improvements in signal integrity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.77-85
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• 2009

With the advent of power semiconductor switching devices, power electronics relating to high frequency electromagnetic eddy current based induction heating technology have become more suitable and acceptable. This paper presents high-frequency induction heating cooking appliance circuit based on the zero current switching-PWM single ended push-pull(ZCS-PWM SEPP) resonant inverter added AC-DC converter. This inverter uses pulse-width-modulation(PWM) control method with active auxiliary quasi-resonant lossless inductor snubbers and a switched capacitor. To improved the transient performance, the PI controller is applied for this system. For the systematic parameter optimization of the PI controller, the gradient-based optimization algorithm is applied. The performance of optimized parameters is evaluated using simulation and experimental test. These results show that the proposed systematic optimal tuning method improve the transient performances of this system.

• Parasites, Hosts and Diseases
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• v.52 no.3
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• pp.291-294
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• 2014

Acanthotrema felis is an intestinal trematode of cats originally reported from the Republic of Korea. Only 1 human case infected with a single adult worm has been previously recorded. In the present study, we report 4 human cases infected with a total of 10 worms recovered after anthelmintic treatment and purging. All 4 patients reside in coastal areas of Jeollanam-do, Korea, and have consumed brackish water fish including the gobies, Acanthogobius flavimanus. The worms averaged 0.47 mm in length and 0.27 mm in width, and had 3 sclerites on the ventrogenital sac; 1 was short and thumb-like, another was long and blunt-ended, and the 3rd was long and broad-tipped. They were identified as A. felis Sohn, Han, & Chai, 2003. Surveys on coastal areas to detect further human cases infected with A. felis are required.

• Food Science and Preservation
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• v.7 no.1
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• pp.94-98
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• 2000

To produce liquor and vinegar using potatoes needs to liquefy and sacchrify potatoes . So selecting the efficient fermenter for proceeding these process successfully is very important . This study was investigated several fermenter and crush types of potatoes for alcohol fermentation. Final sugar contents was high in pottoes saccharificatiion by nuruk or crude enzyme. But pure enzyme and blucoamylase ended liquefaction and saccharificatiion within short ime. So complex type fermenter mixed several fermenters was superior to single type fermenter. Complexfermenter III using crude enzyme and glucoamyulase saccharificed excellently potatoes with 150% of water contents by treatment of 3 hours. Through alcohol fermentation using pressure steamed potatoes (PSP), it could be obtained 6.4% , 150%, of alcohol content and yield. However to perform a series process efficiently , crush steamed pottoes (CSP) was suitable. When it was fermented after saccharification using crush steamed potatoes and complex fermenter III, it could be obtained 6.6% of alcohol and 6.7% of acidity.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.27-34
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• 2005

We analyze in detail axially symmetric theoretical study for the photothermal pulsed radiometry of a cylindrical model. The theoretical solutions describe the transient infrared radiation from the sample heated by short-duration pulsed heating. In the conventional transmission radiometry technique, the excitation source and the detector are on opposite sides of the sample, otherwise in the new single ended radiometry technique, the excitation source and the detector are on same sides of the sample. The analytical solution described for photothermal radiometry in this study would not need to cut or polish samples to measure the thermal diffusivity. Therefore the radial area and axial thickness of samples are not limited. The effects of excitation pulse duration and the area of heat source are discussed.

• ETRI Journal
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• v.24 no.3
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• pp.190-196
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• 2002

This paper presents millimeter wave monolithic microwave integrated circuit (MMIC) low noise amplifiers using a $0.15{\mu}m$ commercial pHEMT process. After carefully investigating design considerations for millimeter-wave applications, with emphasis on the active device model and electomagnetic (EM) simulation, we designed two single-ended low noise amplifiers, one for Q-band and one for V-band. The Q-band two stage amplifier showed an average noise figure of 2.2 dB with an 18.3 dB average gain at 44 GHz. The V-band two stage amplifier showed an average noise figure of 2.9 dB with a 14.7 dB average gain at 65 GHz. Our design technique and model demonstrates good agreement between measured and predicted results. Compared with the published data, this work also presents state-of-the-art performance in terms of the gain and noise figure.

• Journal of Power Electronics
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• v.9 no.4
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• pp.604-611
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• 2009

A dP/dV feedback-controlled MPPT (Maximum Power Point Tracking) method for photovoltaic power systems using II-SEPIC (Isolated Inverse-SEPIC; Single Ended Primary Inductance Converter) is presented and a current-mode dP/dV feedback-controlled MPPT method is devised to apply for the PV power converter system. A control strategy for the current-mode dP/dV feedback control system is developed in this paper and the proposed MPPT shows relatively satisfactory dynamics against rapidly changing insolation conditions. In order to verify the validity and effectiveness of the proposed method, simulations and experiments of the PV power system using II-SEPlC converter are performed. These simulation and experiment results show that the proposed method enables the PV power system to extract maximum power from the photovoltaic module against the solar insolation variation.

• ETRI Journal
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• v.37 no.5
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• pp.906-916
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• 2015

High-speed I/O channels require adaptive techniques to optimize the settings for filter tap weights at decision feedback equalization (DFE) read channels to compensate for channel inter-symbol interference (ISI) and crosstalk from multiple adjacent channels. Both ISI and crosstalk tend to vary with channel length, process, and temperature variations. Individually optimizing parameters such as those just mentioned leads to suboptimal solutions. We propose a joint optimization technique for crosstalk cancellation (XTC) at DFE to compensate for both ISI and XTC in high-speed I/O channels. The technique is used to compensate for between 15.7 dB and 19.7 dB of channel loss combined with a variety of crosstalk strengths from $60mV_{p-p}$ to $180mV_{p-p}$ adaptively, where the transmit non-return-to-zero signal amplitude is a constant $500mV_{p-p}$.