• Proceedings of the KSR Conference
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• 2007.11a
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• pp.172-178
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• 2007

The purpose of Railroad Vehicles License Management in accordance with the Railroad Safety Law is to improve the quality of railroad safety. And the train simulators come into use for training of train operation and testing to issue Railroad Vehicles License. So, It is very important that the simulators for the Railroad Vehicles License Test require to work correctly, to measure driver's operation quality in numerical system and to ensure the justice of license test. In fact, nobody can guarantee that the simulators are feasible performance to use in license test. The simulator for train driver license test can be used effectively for studying of needed performance and quality to test new driver's skill. This study hopefully provides the base for improving the quality of the simulator for train driver's license test and contributes furthermore to improve the simulator development technology and railroad safety.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.367-372
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• 2007

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.4
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• pp.62-68
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• 2010

This work proposes a 10b 100MS/s DAC based on a segmented local matching technique primarily for small chip area. The proposed DAC employing a segmented current-steering structure shows the required high linearity even with the small number of devices and demonstrates a fast settling behavior at resistive loads. The proposed segmented local matching technique reduces the number of current cells to be matched and the size of MOS transistors while a double-cascode topology of current cells achieves a high output impedance even with minimum sized devices. The prototype DAC implemented in a 0.13um CMOS technology occupies a die area of $0.13mm^2$ and drives a $50{\Omega}$ load resistor with a full-scale single output voltage of $1.0V_{p-p}$ at a 3.3V power supply. The measured DNL and INL are within 0.73LSB and 0.76LSB, respectively. The maximum measured SFDR is 58.6dB at a 100MS/s conversion rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.118-118
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• 2009

Low temperature co-fired ceramic (LTCC) is one of promising materials for MEMS structures because it has very good electrical and mechanical properties as well as possibility of making various three dimensional (3D) structures. In this work, piezoelectric pressure sensors based on hybrid LTCC technology were presented. The LTCC diaphragms with thickness of 400 um were fabricated by laminating 12 green tapes which consist of alumina and glass particle in an organic binder. The piezoelectric sensing layer consists of $Pb(ZrTi)O_3$ (PZT) thin film deposited by RF magnetron sputtering method on between top and bottom Au electrodes. The results showed that the fabrication method is very suitable for pressure sensor applications. The PZT films deposited on LTCC diaphragms were successfully grown and were analyzed by using X-ray diffraction method (XRD) and field emission scanning electron microscope (FESEM).

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.701-712
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• 2004

This study investigated reliability of Oriental OB & GY Questionnaires, evaluated the items and correlation relation of differentiation of syndromes of Oriental OB&GY Questionnaires which was used by Dong-Eui OB&GY. We analyzed the results of 553 outpatients's Questionnaires from April 2002 to February 2004. The reliability of Oriental OB&GY Questionnaires above 95% was stagnated blood most, above 90% deficiency of blood, deficiency of Um, heat syndrome, dampness, kidney, liver, heart, spleen, with the exception of phlegm all that was above 80%. The frequency diagnosed of items of differentiation of syndromes dampness, hear, stagnation of Ki was most, the average of item of differentiation of syndromes stagnation of Ki, dampness, deficiency of Ki was most. Correlation coefficient of deficiency of Ki, deficiency of blood, deficiency of Um, cold syndrome, heat, stagnated blood, heart, spleen, kidney, dryness, stagnation of Ki, liver with more than pure question was above 0.8, phlegm was under 0.5. The frequency diagnosed of items of the differentiation of syndromes was not which is related to repeated question and physiology and pathology of oriental medicine.

• Journal of IKEEE
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• v.16 no.3
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• pp.224-234
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• 2012

This paper describes an energy harvesting circuit using solar and vibration energy with MPPT(Maximum Power Point Tracking) control for micro sensor nodes. The designed circuit employs MPPT control to harvest maximum power available from a PZT vibration element and an integrated solar cell. The harvested energies are simultaneously combined and stored in a storage capacitor, and then managed and transferred into sensor node by PMU(Power Management Unit). MPPT controls are implemented using the linear relationship between the open-circuit voltage of an energy transducer and its MPP(Maximum Power Point) voltage. The proposed circuit is designed in a CMOS 0.18um technology and its functionality has been verified through extensive simulations. The designed energy harvesting circuit and integrated solar cell occupy $2.85mm^2$ and $8mm^2$ respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1771-1777
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• 2016

In this thesis, the breakdown voltage characteristics of silicon nanowire N-channel GAA MOSFETs were analyzed through experiments and 3-dimensional device simulation. GAA MOSFETs with the gate length of 250nm, the gate dielectrics thickness of 6nm and the channel width ranged from 400nm to 3.2um were used. The breakdown voltage was decreased with increasing gate voltage but it was increased at high gate voltage. The decrease of breakdown voltage with increasing channel width is believed due to the increased current gain of parasitic transistor, which was resulted from the increased potential in channel center through floating body effects. When the positive charge was trapped into the gate dielectrics after gate stress, the breakdown voltage was decreased due to the increased potential in channel center. When the negative charge was trapped into the gate dielectrics after gate stress, the breakdown voltage was increased due to the decreased potential in channel center. We confirmed that the measurement results were agreed with the device simulation results.

• The Journal of Korea CHUNA Manual Medicine
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• v.4 no.1
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• pp.129-140
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• 2003

Objectives : This study researched into clinical statistics for patients recieved oriental medicine treatments In the Um-sung Gun Dae-so Myun health care center during eight months from May 1 2002 to December 31 2002. The number of object was 246 cases of 234 persons. Results & Conclusions : Analyzing these 234 persons, the rate of males to females was 1 to 2.1. As for the distribution of age, the age of 61 to 70 occupied 44.02 % and the age of 61 to 90 occupied 76.5 % ih the Whole patients. Therefore female was very highly more than male and patients were for the most part, old ages (61 years old and over) Musculoskeletal disease of 202 cases occupied 82.13 %, were the highest rate. At the duration of disease 1 year to 5 years occupied 26.92 %, was the highest. The Grade II was the most of the sign of patients at first visit, it occupied 47.86 %, The Fair(+) and over effect of treatments occupied 96.84 %, the failure(-) Of effect treatments occupied 3.16 %. As for the duration of treatment, the case of 2 times to 5 times visit occupied 38.03 %, was the highest. By medication of treatment, O-juk-san(五積山) occupied 35.10 %, was the highest rate. The average 8.67 persons treated with oriental medicine a day, the average 1.36 person received the first medical examination a day.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.4 s.334
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• pp.61-68
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• 2005

A chip, which can fast encoder the audio data to AAC (Advanced Audio Coding) LC(Low Complexity) that is MPEG-2 audio standard, has been designed on the basis of a 32 bits DSP core and fabricated with 0.25um CMOS technology. At first, the various optimization methods for implementing the algerian are devised to reduce the memory size and calculation cycles. FFT(Fast Fourier Transform) hardware block is added to the DSP core to get the more reduction of the calculation cycles. The chips has the size of $7.20\times7.20 mm^2$ and about 830,000 equivalent gates, can carry out AAC encoding under 70MIPS(Million Instructions per Second).

• Journal of IKEEE
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• v.15 no.2
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• pp.134-142
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• 2011

This paper describes a tripple-mode high-efficiency DC-DC buck converter. The DC-DC buck converter operate in PWM(Pulse Width Modulation) mode at moderate to heavy loads(100mA~500mA), in PFM(Pulse Frequency Modulation)at light loads(1mA~100mA), and in LDO(Low Drop Out) mode at the sleep mode(<1mA). In PFM mode DPSS(Dynamic Partial Shutdown Strategy) is also employed to increase the efficiency at light loads. The triple-mode converter can thus achieve high efficiencies over wide load current range. The proposed DC-DC converter is designed in a CMOS 0.18um technology. It has a maximum power efficiency of 96.4% and maximum output current of 500mA. The input and output voltages are 3.3V and 2.5V, respectively. The chip size is 1.15mm ${\times}$ 1.10mm including pads.