An application of molecular biology in medicine ; detection of polymorphic marker for the type I collagene gene to Ehlers-Danlos syndrom type Ⅳ

Young, kil,Choi, M.D 경희대학교 동서의학연구소 1991 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1991 No.3

Design of a 99-㏈ DR Single-bit Fourth-order High-performance Delta-Sigma Modulator

Youngkil Choi,Hyungdong Roh,Hyunseok Nam,Jeongjin Roh 대한전자공학회 2007 ITC-CSCC :International Technical Conference on Ci Vol.2007 No.7

A fourth-order single-bit delta-sigma modulator for audio codec is presented. The loop-filter is composed of both feedback and feed-forward paths, and the modulator is implemented using fully differential switched-capacitor techniques. A test chip was fabricated in a 0.18-㎛ standard CMOS process. The chip core area is 1.22 ㎟, and its power consumption is 5.6 ㎽ from a 3.0-V power supply. Measurement results show that a maximum 99-㏈ dynamic range is achievable at a clock rate of 3.2 ㎒ for the 20-㎑ bandwidth.

A 0.018% THD+N, 88-dB PSRR PWM Class-D Amplifier for Direct Battery Hookup

Youngkil Choi,Wonho Tak,Younghyun Yoon,Jeongjin Roh,Sunwoo Kwon,Jinseok Koh IEEE 2012 IEEE journal of solid-state circuits Vol.47 No.2

<P>A low-distortion third-order class-D amplifier that is fully integrated into a 0.18-μ m CMOS process was designed for direct battery hookup in a mobile application. A class-D amplifier for direct battery hookup must have a sufficiently high power supply rejection ratio (PSRR) in preparation for noise, such as when a global system for mobile communications (GSM) bursts ripples through the system power line. This amplifier has a high PSRR of 88 dB for 217-Hz power supply ripples, using a third-order loop filter. System performance and stability are improved by applying the design technique of input-feedforward delta-sigma (ΔΣ) modulators to the pulse-width modulation (PWM) class-D amplifier. A filterless method that can remove the external LC filter is employed, which offers great advantages in terms of PCB space and system cost. This amplifier achieves a power efficiency of 85.5% while delivering an output power of 750 mW into an 8-Ω load from a 3.7-V supply voltage. Maximum achieved output power at 1% total harmonic distortion plus noise (THD+N) from a 4.9-V supply voltage into an 8-Ω load is 1.15 W. This class-D amplifier is designed to have a broad operational range of 2.7-4.9 V for the direct use of mobile phone battery power. It has a total area of 1.01 mm<SUP>2</SUP> and achieves a THD+N of 0.018%.</P>

Fountain Code Design for Broadcasting Systems With Intermediate-State Users

Youngkil Suh,Jonghyun Baik,Rahnavard, Nazanin,Heo, Jun Institute of Electrical and Electronics Engineers 2015 IEEE Transactions on Communications Vol. No.

<P>Several studies on fountain codes have proposed degree distribution optimization schemes to maximize symbol recovery rate. However, if the number of transmitted coded symbols is limited or the channel erasure probability is high, it may be impossible that a user recovers all of the data symbols regardless of degree distribution employed by the source. In this study, we focus on a new system model where one source transmits fountain-coded symbols to multiple users who already possess some data symbols and coded symbols. Assuming that each user can transmit a feedback packet containing its own state information before the source transmits coded symbols, we propose two types of degree distribution design schemes that are suitable for the system model. Simulation results demonstrate the efficiency of our proposed schemes by comparing with conventional methods in terms of symbol recovery rate and full recovery rate.</P>

A Bufferless Interface for Single-Ended ECM Sensors

Youngkil Choi,Hyungdong Roh,Jeongjin Roh IEEE 2012 IEEE transactions on instrumentation and measureme Vol.61 No.2

<P>This paper presents a bufferless interface that can be directly connected to a single-ended capacitive sensor such as an electret condenser microphone. A high-input impedance interface is developed using only a continuous-time loop filter, whereas conventional interface circuits are composed of a buffer, a preamplifier, an antialiasing filter, and a high-order switched-capacitor loop filter. Equipped with an active <I>gm</I>-<I>C</I> integrator, this interface chip is designed to implement all the required functions, i.e., high-input impedance buffering, preamplification, antialiasing filtering, and analog-to-digital conversion. The inherent antialiasing filtering function also provides a significant advantage in terms of silicon areas and power consumption. The complete interface channel achieves a 75-dB dynamic range and a 60.3-dB signal-to-noise-plus-distortion ratio over a 25-kHz signal band, which satisfies the requirements for electret microphones. The power consumption of the interface channel is 600 μW, and the chip dissipates a total of 860 μW from the 3.3-V supply.</P>

COMp-Ko and Case Markers

Youngkil Jeong 한국생성문법학회 1999 생성문법연구 Vol.9 No.1

A 99-dB DR Fourth-Order Delta–Sigma Modulator for 20-kHz Bandwidth Sensor Applications

Youngkil Choi,Jeongjin Roh,Hyungdong Roh,Hyunseok Nam,Songjun Lee IEEE 2009 IEEE transactions on instrumentation and measureme Vol.58 No.7

<P>A fourth-order single-bit delta-sigma modulator is presented for sensor applications. The loop filter is composed of both feedback and feedforward paths, and the modulator is implemented using fully differential switched-capacitor techniques. A test chip was fabricated in a 0.18-mum standard complementary metal-oxide semiconductor (CMOS) process. The chip core area is 1.22 mm<SUP>2</SUP>, and its power consumption is 5.6 mW from a 3.0-V power supply. Measurement results show that a maximum 99-dB dynamic range is achievable at a clock rate of 3.2 MHz for the 20-kHz bandwidth. The designed chip is targeted for high-accuracy and wide-bandwidth sensor applications such as the resistor-based current sensors and the Hall-effect sensors in motor control systems.</P>

고경도강의 건식연삭과 습식연삭에 관한 연구

전영길(Youngkil Jeon),하상백(Sangbaek Ha),손기락(Girak Son),최환(Hwan Choi),이종찬(Jongchan Lee) 한국정밀공학회 1999 한국정밀공학회 학술발표대회 논문집 Vol.1999 No.5월

자동차보험 승낙피보험자와 운전피보험자에 관한 연구 - 대법원 판례를 중심으로 -

김영길 ( Youngkil Kim ) 한국손해사정학회 2016 손해사정연구 Vol.14 No.-

자동차보험의 경우 피보험자의 범위를 기명피보험자 외에도 친족피보험자, 승낙피보험자, 사용피보험자, 운전피보험자 등으로 그 범위를 확대하여 인정하고 있다. 그런데 이들 피보험자 개념이 난해하여 손해사정실무 및 소송실무에서 해석상 다툼이 빈발하고 있다. 예컨대 손해사정실무에서는 렌터카회사(기명피보험자)로부터 렌터카(피보험자동차)를 빌려간 뒤 렌터카회사(기명피보험자)의 의사에 명백히 반하여 렌터카를 제3자에게 재차 빌려주거나 운전케 한 임차인을 승낙피 보험자로 보고 있으나 정작 이에 대한 관련 판례나 연구문헌은 나와 있지 않은 실정이다.또 피보험자동차를 운전기사와 함께 임차하여 작업중 임차인 본인이 사상한 경우 그 임차인이 승낙피보험자에 해당하는지 여부, 피보험자동차를 무단으로 운전한 고용운전자가 운전피보험자에 해당하는지 여부에 대하여는 보험이론에 반하는 판례로 인해 논란이 가중되고 있다. 이에 본 논문에서는 렌터카회사로부터 렌터카를 빌려간 뒤 렌터카회사의 의사에 명백히 반하여 그 자동차를 제3자에게 재차 빌려주거나 운전케 한 임차인과 피보험자동차를 운전기사와 함께 임차하여 작업 중 임차인 본인이 사상한 경우 그 임차인은 승낙피보험자 해당되지 않는다는 점, 운전피보험자는 통상 기명피보험자에 고용되어 피보험자동차를 운전하는 고용운전자(=자배법상 운전자)를 뜻 하지만 반드시 고용운전자에 국한하지는 않으며 고용운전자라 하더라도 무단으로 운전한 경우에는 비록 기명피보험자 등을 위하여 운전한다는 의사로 운전하였다고 하더라도 운전피보험자에 해당하지 않는다는 점 등을 명확히 하고 승낙피보험자와 운전피보험자 조항의 바람직한 해석론 및 약관개정론을 제시해 보고자 한다. 본 연구를 계기로 향후 본 논문에서 제기한 의제에 대한 활발한 논의와 연구 및 합리적 방향으로의 약관개정이 있기를 기대해 본다. In case of automobile insurance, it expands the range of the insured other than named insured to relative insured, allowed insured, employer insured, driving insured. However, the concept of the insured is unexpectedly too complicated to be generally acceptable, so many disputes occur for interpretation of the insured on claim adjustment field and lawsuit field. For example, in case of claim adjustment field recognizes the lessee who let a third party to drive or re-lease the insured car that lessee rented from the rental car company be allowed insured, however, there is not any judicial precedent or research case. Additionally, the dispute continues to rise due to opposing verdicts in relation to a lessee should be recognized as allowed insured when the lessee was hurt or killed by a driver rented along with insured car and the employee driver who drove insured car without the named insured`s permission is the driving insured or not. This thesis will establish the lessee who let a third party to drive or re-lease the insured car that lessee rented from the rental car or the lessee was hurt or killed by a driver rented along with the insured car company should not be recognized as allowed insured; though the driving insured generally describes the employee driver who drives the insured car hired by named insured, does not always limit the employee driver, and even the employee driver is recognized as the driving insured, he or she should not be recognized as driving insured even the purpose of driving was for named insured, if the driving was unauthorized. This will be discussed based on verdicts of precedents and references and it will guide to set the desirable theory of interpretation and Revision of clause. With this as the research, it expects to lead active discussion and rational Revision of clause for the proposed subject on this thesis.

토크컨버터 댐퍼 스프링의 강성의 변화가 동적 히스테리시스에 미치는 영향에 관한 연구

윤영길(Youngkil Yoon),권오범(Ohbeom Kwon),이인태(Intae Lee) 한국자동차공학회 2013 한국자동차공학회 학술대회 및 전시회 Vol.2013 No.11