• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권7호
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• pp.339-342
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• 2005

We present a new high-frequency equivalent circuit model for 52pin QFP used in typical IC's and extract R, L, and C values of this circuit model using a 3-D E & M field simulator. Futhermore, L and C value variations as a function of Pin number due to the shape differences of the leads have been fitted to 2nd order polynomials in order to extend the applicability of this model.

• 한국지반환경공학회 논문집
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• 제11권6호
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• pp.5-20
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• 2010

1차원 등가선형 지반응답해석은 지반에 의한 지진동의 증폭현상을 모사하는데 널리 사용되고 있다. 등가선형해석은 적은 수의 입력변수를 필요로하므로 사용하기 편리하며 해석 소요시간이 짧다는 장점을 가지고 있는 반면, 시간에 따라서 변화하는 지반의 비선형 거동을 모사할 수 없으며 일정한 전단탄성계수와 감쇠비를 해석 내내 적용하는 선형해석이라는 단점을 가지고 있다. 이와 같은 등가선형해석의 단점을 보완하기 위하여 진동 주파수와 변형률과의 관계를 모사하는 다양한 형태의 수정된 등가선형해석기법들이 개발되었다. 수정된 기법들은 전단변형률 푸리에 스펙트럼을 사용한다는 점에서는 동일하지만, 이로부터 변형률의 주파수 의존도를 정의하는 과정에서는 차이를 보이고 있다. 본 연구에서는 두 가지 수정된 등가선형해석기법들의 정확성을 평가하기 위하여 국내에서 조사된 두 개의 토층에서 일련의 비선형, 등가선형, 수정된 등가선형 지반응답해석을 수행하였다. 해석 결과, 수정된 등가선형해석기법들은 고주파수 요소를 과대 예측할 수 있으며, 특히 고주파수 요소가 풍부한 인공지진파를 입력 지진파로 사용하였을 경우 비현실적인 응답이 계산될 수 있는 것으로 나타났다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.82-89
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• 2007

Sound transmission characteristics are investigated on the corrugated steel and aluminium extruded panels used for railway vehicles. Sewell-Sharp-Cremer(SSC) model, equivalent orthotropic plate model and equivalent mass law are applied to predict the sound transmission loss. The predicted values of the sound transmission loss are compared with the measured values. The reliability and the limitation of the prediction models are investigated. For the corrugated panels and honeycomb panels, the coincidence and local resonance severely deteriorate the sound insulation performance around the corresponding frequency bands. The result of the study shows that the equivalent orthotropic plate model and the SSC model can be used as good prediction models, if the coincidence frequency or local resonance frequency is correctly applied.

• 조명전기설비학회논문지
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• 제29권2호
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• pp.104-112
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• 2015

This paper deals with an methodology for acquiring optimal order of rational function model in FDNE(frequency dependent network equivalents) with GA(genetic Algorithm). In order to analyze the modern power system with huge complexity, an practical and efficient equivalent model is needed which represents the system's characteristics of transient phenomenon. this paper shows developing a z domain rational function model which have the resultant coefficient from proposed GA simulation. To demonstrate this methodology, some simulations are performed with practical power system of NZ which applied with fault condition and nonlinear converter load.

• 한국식품과학회지
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• 제22권5호
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• pp.582-589
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• 1990

본 고에서는 Equivalent time과 Equivalent temperature를 활용하여 Kinetic parameters를 결정하는 새로운 방법을 제안하였다. 본 방법의 타당성을 두 가지의 kinetic data 즉, 계산치와 실험치를 이용하여 예시하였다. 계산치는 그 Kinetics가 잘 알려진 세 가지 화학반응에 대해 임의의 등온가열조건을 적용하여 계산하였고 실험치는 2% 설탕용액을 사용하여 0.0005N 염산용액을 사용하여 가수분해가 일어나는 정도를 효소반응을 이용하여 측정하였다. 본 방법에 의해 결정된 활성화 에너지와 Frequency factor는 각각 $104.74{\pm}1.87KJ/mol$과 $5.26{\times}10^{14)hr^{-1}$이었으며 이들 값은 보고된 결과와 잘 일치되었다.

• 한국지진공학회논문집
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• 제19권1호
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• pp.1-11
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• 2015

In order to perform a soil-isolation-structure interaction analysis of seismically isolated nuclear power plant (NPP) structures, the nonlinear behavior of a seismic isolation system may be converted to an equivalent linear model used in frequency domain analysis. Seismic responses for seismically isolated NPP containment structures subjected to a simple artificial acceleration history and different site class earthquakes are evaluated for the equivalent-linear and nonlinear models that have been applied to lead-rubber bearing (LRB) modeling. It can be observed that the maximum displacements of the equivalent linear model are larger than that of the nonlinear model. From the floor response spectrum analysis for the top of NPP containment structures, it can be observed that the spectral acceleration of an equivalent linear model at about 0.5 Hz frequency is about 2~3 times larger than that of a nonlinear model.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.5-8
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• 2004

We have investigated equivalent-circuit analysis of organic light-emitting diodes using frequency-dependent response of $ITO/Alq_3(60nm)/Al$ device at two different bias voltages. Complex impedance Z of the device was measured in the frequency range of 40Hz~1MHz. A Cole-Cole plot shows that there are two dielectric relaxations at the bias below turn-on voltage, and one relaxation at the bias above turn-on voltage. We are able to interpret the frequency-dependent response in terms of equivalent-circuit model of contact resistance $R_s$ in series with parallel combination of resistance $R_p$ and capacitance $C_p$. We have obtained contact resistance $R_s$ around $90{\Omega}$, mainly from the ITO anode.

• ETRI Journal
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• 제25권1호
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• pp.9-18
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• 2003

We mathematically analyze the passband vestigial sideband (VSB) system for the Advanced Television Systems Committee (ATSC) digital television standard and present a baseband-equivalent VSB model. The obtained baseband VSB model is represented by convolution of the transmission signal (before modulation) and the baseband equivalent of the complex VSB channel. Due to the operation of the physical channel as an RF passband and the asymmetrical property of VSB modulation, it is necessary to use a complex model. However, the passband channel may be reduced to an equivalent baseband. We show how to apply standard channel model information such as delay, gain, and phase for multiple signal paths to compute both the channel frequency response with a given carrier frequency and the resulting demodulated impulse response. Simulation results illustrate that the baseband VSB model is equivalent to the passband VSB model.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.188-191
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• 2004

We have investigated equivalent-circuit analysis of organic light-emitting diodes in $ITO/TPD/Alq_3/Al$. Complex impedance Z of the device was measured in the frequency range of $40Hz{\sim}1MHz$. We are able to interpret the frequency-dependent response in terms of equivalent-circuit model of contact resistance $R_s$ in series with two parallel combination of $R_{TPD},\;C_{TPD}\;and\;R_{Alq3},\;C_{Alq3}$.

• 소음진동
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• 제10권1호
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• pp.153-159
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• 2000

This paper presents a new method for including the dynamic stiffness of the stationary parts in rotordynamic analysis. As a consequence of the support dynamics, critical speeds are varied and/or additional critical speeds are introduced. Therefore, dynamic effects of the support are often significant in high speed turbomachinery, but most of analysis has considered the support as a rigid body or a simple structure. The proposed method is based on the coupled characteristics of the driving point and transfer frequency response functions of the support system to model the equivalent spring-mass series in finite element analysis. To demonstrate the applicability of the simulation procedures provided, it is applied to the rotor model of the double suction centrifugal pump. Results of the suggested equivalent-support rotor model including coupled effects agree well with the entire pump model.