• ETRI Journal
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• 제42권5호
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• pp.790-798
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• 2020

Herein, a low-ripple coarse-fine digital low-dropout regulator (D-LDO) without ringing in the transient state is proposed. Conventional D-LDO suffers from a ringing problem when settling the output voltage at a large load transition, which increases the settling time. The proposed D-LDO removes the ringing and reduces the settling time using an auxiliary power stage which adjusts its output current to a load current in the transient state. It also achieves a low output ripple voltage using a comparator with a complete comparison signal. The proposed D-LDO was fabricated using a 65-nm CMOS process with an area of 0.0056 μ㎡. The undershoot and overshoot were 47 mV and 23 mV, respectively, when the load current was changed from 10 mA to 100 mA within an edge time of 20 ns. The settling time decreased from 2.1 ㎲ to 130 ns and the ripple voltage was 3 mV with a quiescent current of 75 ㎂.

• ETRI Journal
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• 제32권4호
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• pp.520-529
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• 2010

In this paper, we present a low-voltage low-dropout voltage regulator (LDO) for a system-on-chip (SoC) application which, exploiting the multiplication of the Miller effect through the use of a current amplifier, is frequency compensated up to 1-nF capacitive load. The topology and the strategy adopted to design the LDO and the related compensation frequency network are described in detail. The LDO works with a supply voltage as low as 1.2 V and provides a maximum load current of 50 mA with a drop-out voltage of 200 mV: the total integrated compensation capacitance is about 40 pF. Measurement results as well as comparison with other SoC LDOs demonstrate the advantage of the proposed topology.

• 제어로봇시스템학회논문지
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• 제3권6호
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• pp.576-581
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• 1997

DC-DC converter with chopper is seen to have problems, such as, loop instability and degradation of transient response, due to the interaction between input filter and switching regulator. In this paper, the switching regulator consisting of input filter and double chopper is analyzed, and the state space model at continuous current mode and the transfer function between duty ratio of switching pulse and output voltage are derived. The controller in this paper is designed as feedforward(P) and feedback(PI) control scheme to minimize the variation of output voltage, and computer simulation results are presented to show the performance of the proposed controller.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2005년도 International Meeting of the Microbiological Society of Korea
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• pp.152-153
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• 2005

• 한국작물학회:학술대회논문집
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• 한국작물학회 2021년도 춘계학술대회
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• pp.112-112
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• 2021

• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.50-50
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• 2003

We have identified and analysed a putative response regulator two-component gene (CaSKN7) from Candida albicans and its encoding protein (CaSkn7). CaSKN7 has an open reading frame of 1677bp. CaSKN7 encodes a 559 amino acid protein (CaSkn7) with an estimated molecular mass of 61.1 kDa. CaSKN7 is a homologue of a Saccharomyces cerevisiae SKN7 that is the regulator involved in the oxidative stress response. To study the role of CaSKN7, we constructed a CAI4-derived mutant strain carrying a homozygous deletion of the CaSKN7 gene. In the caskn7 disruptant cells, the formation of germ tube require shorter time than that in the congenic wild-type strain but the growth of mycelium delayed in liquid media. In contrast, the caskn7 disruptant cells attenuate the differentiation in solid media and the virulence in mouse model system. Expression level of hypha-specific and virulence genes - HYR1, ECE1, HWP1, and ALS1 - in the caskn7 disruptant cells increased as compared with that in the congenic wild-type strain in 10％ serum YPD. Skn7 in 5. cerevisiae was found to bind the HSE element from the SSA promoter, Also, CaSkn7 contains heat shock factor DNA-binding domain and the promoters of these genes have HSE-like sties. Therefore these results show that CaSKN7 regulate the differentiation and virulence of C. albicans.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 춘계 학술발표회논문집
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• pp.259-266
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• 2003

This paper begins with the seismic performance evaluation of an existing building, which exhibits the need of additional damping to reduce its response. Required damping ratio is found by capacity spectrum method to satisfy a target response. It is expressed with the design parameter of active mass damper by adopting Linear Quadratic Regulator, Optimal gains are obtained and then weighting matrices are found. Finally the seismic performance by added active mass damper is demonstrated, which satisfies the target response.

• ETRI Journal
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• 제39권3호
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• pp.373-382
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• 2017

A new internally compensated low drop-out voltage regulator based on the cascoded flipped voltage follower is presented in this paper. Adaptive biasing current and fast charging/discharging paths have been added to rapidly charge and discharge the parasitic capacitance of the pass transistor gate, thus improving the transient response. The proposed regulator was designed with standard 65-nm CMOS technology. Measurements show load and line regulations of $433.80{\mu}V/mA$ and 5.61 mV/V, respectively. Furthermore, the output voltage spikes are kept under 76 mV for 0.1 mA to 100 mA load variations and 0.9 V to 1.2 V line variations with rise and fall times of $1{\mu}s$. The total current consumption is $17.88{\mu}V/mA$ (for a 0.9 V supply voltage).

• 한국산학기술학회논문지
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• 제15권10호
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• pp.5980-5987
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• 2014

디젤엔진의 사용은 루돌프 디젤에 의하여 발명된 이후 산업의 발달을 이끌어가는 중추적인 역할을 하고 있다. 2013년 기준으로 국내의 디젤엔진의 차량은 7,395,739대이다. 디젤엔진에서의 인젝터는 엔진의 구동에 직접적인 역활을 수행하기 때문에 성능향상에 대한 연구는 지속적으로 이루어지고 있다. 본 연구는 운행 중인 디젤차량의 매연의 농도와 인젝터 클리닝 전 후의 관계를 비교분석하기 위하여 인젝터 클리닝 전 후의 매연의 농도를 KD147 모드("운행차 수시점검 및 정기검사의 배출허용기준")로 측정하여 인젝터 클리닝이 매연 저감에 미치는 영향에 대하여 실험적으로 고찰하였다. 실험결과 인젝터 클리닝 후의 매연의 농도가 20% 이상 감소하는 것을 확인하였으며 매연의 농도의 감소율은 매연의 발생량이 클수록 증가하는 것으로 나타났다.

• Smart Structures and Systems
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• 제18권6호
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• pp.1111-1123
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• 2016

The present study aims at proposing an analytical method for semi-active structural control by using block pulse functions. The performance of the resulting controlled system and the requirements of the control devices are highly dependent on the control algorithm employed. In control problems, it is important to devise an accurate analytical method with less computational expenses. Block pulse functions (BPFs) set proved to be the most fundamental and it enjoyed immense popularity in different applications in the area of numerical analysis in systems science and control. This work focused on the application of BPFs in the control algorithm concerning decrease the computational expenses. Variable orifice dampers (VODs) are one of the common semi-active devices that can be used to control the response of civil Structures during seismic loads. To prove the efficiency of the proposed method, numerical simulations for a 10-story shear building frame equipped with VODs are presented. The controlled response of the frame was compared with results obtained by controlling the frame by the classical clipped-optimal control method based on linear quadratic regulator theory. The simulation results of this investigation indicated the proposed method had an acceptable accuracy with minor computational expenses and it can be advantageous in reducing seismic responses.