• Title/Summary/Keyword: Scale constant

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ANALYSIS OF HEAT LOSS IN A CONSTANT VOLUME MICRO COMBUSTOR (초소형 정적 연소실의 열손실 분석)

  • Na, Han-Bee;Lee, Dae-Hoon;Kwon, Se-Jin
    • 한국연소학회:학술대회논문집
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    • 2002.11a
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    • pp.231-235
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    • 2002
  • A theoretical and experimental study on the combustion process in a constant volume micro combustor is described. Unlike in a macro scale constant volume combustor, the heat loss to the wall plays a major role in flame propagation in a micro micro combustor. In order to analyze the effect of heat loss on combustion phenomena, pressure transition from ignition was measured. A number of cylindrical micro combustors with different diameter and depth were used for experiment to study the effect of length scales and shape factor. The diameter of combustor ranged from 7.5mm to 22.5 mm and the height of cylinder was from 1mm to 4mm. Initial pressure was also varied for the experiment. The diagnostic methods were severely limited due to the size of the apparatus and uncertainties of certain quantities to be measured in a small-scale environment. An analytical method to derive physical quantities that are essential for performance prediction from the pressure measurements is described.

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Scaling theory to minimize the roll-off of threshold voltage for nano scale MOSFET (나노 구조 MOSFET의 문턱전압 변화를 최소화하기 위한 스케일링 이론)

  • 김영동;김재홍;정학기
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.494-497
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    • 2002
  • In this paper, we have presented the simulation results about threshold voltage of nano scale lightly doped drain (LDD) MOSFET with halo doping profile. Device size is scaled down from 100nm to 40nm using generalized scaling. We have investigated the threshold voltage for constant field scaling and constant voltage scaling using the Van Dort Quantum Correction Model(QM) and direct tunneling current for each gate oxide thickness. We know that threshold voltage is decreasing in the constant field scaling and increasing in the constant voltage scaling when gate length is reducing, and direct tunneling current is increasing when gate oxide thickness is reducing. To minimize the roll-off characteristics for threshold voltage of MOSFET with decreasing channel length, we know u value must be nearly 1 in the generalized scaling.

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Three level constant stress accelerated life tests for Weibull distribution

  • Moon, Gyoung Ae
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.1
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    • pp.281-288
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    • 2015
  • In this paper, the maximum likelihood estimators and confidence intervals for parameters of Weibull distribution are derived under three level constant stress accelerated life tests and the assumption that a log quadratic relationship exits between stress and the scale parameter ${\theta}$. The compound linear plan proposed by Kim (2006) is used to allocate the test units at each stress level, which performed nearly as good as the optimum quadratic plan and had the advantage of simplicity. Some simulation studies are given.

AN AUTOMATED TEST FACILITY FOR EVALUATING FRICTION MATERIAL FOR AUROMOTINE-TYPE DISC BRAKES

  • Hancke, G.P.;Zietsman, R.E.
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.776-780
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    • 1989
  • A constant torque dynamometer with associated instrumentation and control functions for the development of friction materials for automotive-type disc brakes, has been developed. Full scale disc pads are subject to a series of intermittent brake applications at a constant rotational speed of the brake disc and constant braking power. This paper gives a description of the dynamometer and an example of results obtained.

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Development of body-fat measurable electronic scale. (체지방측정이 가능한 전자식 체중계의 개발)

  • Choi, Byung-Sang;Kim, Il-Hwan;Park, Chan-Won
    • Journal of Industrial Technology
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    • v.26 no.B
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    • pp.243-248
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    • 2006
  • The purpose of this study is to design a body-fat measurable electronic scale which can measure body impedance and weight. The hardware configuration of this system for the body-fat measurement includes a sinewave constant current generator, a analog switch circuit and a microprocessor with peripheral interface as well as electronic scale circuit. And the dedicated software is also designed for calculating body fat and body composition analysis from the result of the measurement.

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Understanding of Laminar Burning Velocity within a Length Scale Domain (길이 스케일이 관여된 층류 화염의 연소 속도 이해)

  • Jung, Yongjin;Lee, Min Jung;Kim, Nam Il
    • 한국연소학회:학술대회논문집
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    • 2015.12a
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    • pp.77-78
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    • 2015
  • Laminar burning velocities have been predicted by constant volume combustion chamber, counter flow burner and others. In this study, the measured flame propagation velocities in an assembled annular stepwise diverging tube were plotted with respect to equivalence ratio, length scale, and velocity scale. Three dimensional approach to understand the flame propagation velocity including laminar burning velocity is investigated, and the surface provides the correlation among quenching distance, propagation velocity, and equivalence ratio.

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Performance Relation Analysis of CLR, Buffer Capacity and Delay Time in the ATM Access Node (ATM 접속노드에서 셀 손실율과 버퍼용량 및 지연시간의 상관관계 분석)

  • 이하철;이병섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.945-950
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    • 2002
  • In this paper the performance evaluations on Asynchronous Transfer Mode(ATM) access node are performed in the ATM access network which consists of access node and channel. The performance factors of access node are Cell Loss Ratio(CLR), buffer capacity and delay time. Both the ATM cell-scale queueing model and burst-scale queueing model are considered as the traffic model of access node for various traffic types such as Constant Bit Rate(CBR), Variable Bit Rate(VBR) and random traffic in the ATM access networks. Based on these situations, the relation of CLR, buffer capacity and delay time is analyzed in the ATM access node.

Evaluation of the Spring Constant of a Micro Coil Spring (마이크로 코일 스프링의 스프링 상수 평가)

  • Lee J. K.;Jeon B. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.255-259
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    • 2001
  • The spring constant of a micro coil spring was measured by uniaxial tensile test. The inner diameter of it is $35{\mu}m$ and the pitch size is about $23{\mu}m$. A suing constant measurement system was developed. It consists of control units, load cell units, linear stages and several specially designed jigs and fixtures. Load and displacement are measured using a commercial load cell of 1000g capacity and a magnetic scale of $0.5{\mu}m$ resolution. In this study, a method to measure the spring constant of micro coil spring is presented and the relationship between misalignment of specimen and measurement error is discussed.

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State feedback optimal control of large-scale discrete-time systems with time-delays (시간지연이 있는 대규모 이산시간 시스템의 상태궤환 최적제어)

  • 김경연;전기준
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.219-224
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    • 1988
  • A decentralised computational procedure is proposed for the optimal feedback gain matrix of large-scale discrete-time systems with time-delays. The constant feedback gain matrix is computed from the optimal state and input trajectries obtained hierarchically by the interaction prediction method. All the calculation in this approach are done off-line. The resulting gains are optimal for all the initial conditions. The interaction prediction method is applied to time-delay large-scale systems with general structures by extending the dimensions of coupling matices. A numerical exampie illustrates the algorithm.

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A Study Harmony on “Question & Answer” of Pat Metheny (Pat Metheny의 작품 "Question & Answer“의 화성분석)

  • Kim, Hyeong-June;Kim, Dae-Seung
    • Proceedings of the KAIS Fall Conference
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    • 2010.05b
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    • pp.755-758
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    • 2010
  • 본 논문에서는 현재 Jazz에서 사용되어지는 화성기법을 Pat Metheny의 작품인 “Question & Answer”를 통해서 알아보았다. D Minor Pentatonic Scale이 선율에 주로 사용된 본 작품은 Intro부분에서는 Quater Voicing이 사용되었다. A 부분에서는 Line Cliche와 D Minor Scale과 D Harmonic Minor Scale의 Diatonic Chord를 사용하였지만 A Aeolian Mode적인 기법이 A부분 셋 번째 단에서 사용되어 Modal적인 분위기도 연출 하였으며 B부분에서는 John Coltrane이 자주 사용하였던 3 Tonic 기법이 사용되면서 동질의 화성이 일정간격으로 움직이는 Constant Structure기법도 사용되었다.

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