• E2M - 전기 전자와 첨단 소재
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• 제10권8호
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• pp.783-793
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• 1997

A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density stress current transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width $\times$ length 10 $\times$1${\mu}{\textrm}{m}$, 10 $\times$ 0.3${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gaves unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

• 한국안전학회지
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• 제16권4호
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• pp.29-38
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• 2001

The purpose of this paper is to evaluate the structural integrity of a reactor pressure vessel subjected to the pressurized thermal shock(PTS) during the transient events, such as main steam line break(MSLB) and small break loss of coolant accident(SBLOCA). For postulated surface or subsurface cracks, variation curves of stress intensity factor are obtained by using the three different methods, including ASME section XI code anlysis, the finite element alternating method and the finite element method. From the stress intensity factor curves, the maximum allowable nil-ductility transition temperatures(RT/NDT/) are determined by the tangent criterion and the maximum criterion for various crack configurations and two initial transient events. As a result of the analysis, it is noted that axial cracks have smaller maximum allowable RT$_{NDT}$ values than same-sized circumferential cracks for both the transient events in the case of the tangent criterion. Axial cracks have smaller RT$_{NDT}$ values than same-sized circumferential cracks for MSLB and circumferential cracks have smaller values than axial cracks for SBLOCA in the case of the maximum criterion.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.59-62
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• 2000

A VLSI implementation of a self-learning neural network integrated circuits using a linearity synapse transistor is investigated. The thickness dependence of oxide current density, stress current, transient current and channel current has been measured in oxides with thicknesses between 41 and 112 $\AA$, which have the channel width$\times$length 10$\times$1${\mu}{\textrm}{m}$ respectively. The transient current will affect data retention in synapse transistors and the stress current is used to estimate to fundamental limitations on oxide thicknesses. The synapse transistor has represented the neural states and the manipulation which gave unipolar weights. The weight value of synapse transistor was caused by the bias conditions. Excitatory state and inhitory state according to weighted values affected the drain source current.

• 한국강구조학회 논문집
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• 제12권3호통권46호
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• pp.269-279
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• 2000

차량하중의 증가 및 부식 등에 의해 손상된 강교량 구조물들은 보수 보강이 요구되어진다. 손상부채를 보수 보강하는 방법은 단면결손이 없다는 장점을 가진 용접에 의한 보수방법이 유리하다. 3차원 탄소성해석 결과를 토대로 공용중 보수용접에 의해 생기는 응력과 변형의 거동에 대해 연구하였다. 균열이 있는 부재에 하중만 작용할 경우 과도 응력의 크기는 보수용접균열길이 및 균열깊이가 큰 순으로 크다. $80MPa({\sigma}_y/3)$ 및 $140MPa({\sigma}_a)$의 응력 작용시 보수용접에 의해 발생되는 응력의 크기는 무응력 상태에서 보수용접시 발생되는 응력의 크기와 하중재하에 의해 생긴 응력의 크기의 합과 비슷하다. 응력 작용시 보수용접에 의해 발생되는 용접선방향 인장과도응력 성분은 부재폭에 대한 균열 길이비(1/b)가 커지면 커짐을 알 수 있다. 또한, 응력 작용시 보수용접에 의해 발생되는 용접선 직각방향의 면내수축변위의 크기는 보수용접길이가 긴순으로 크다.

• 한국공작기계학회논문집
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• 제14권1호
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• pp.37-43
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• 2005

Plant pipe has a fatigue life which is induced by repeated stress come from the variation of temperature and pressure. To avoid the fatigue crack of plant pipe which is produced by long term repeated stress, plant operator has to limit the mont of operating transient. This paper introduced the study result about discrimination methodology of plant transient by using the fuzzy pattern recognition. As result of applying the fuzzy pattern recognition to actual plant operation data, it is confirmed that fuzzy pattern recognition methodology can be useful for the comparison of similarity for the transients of similar output but has different time pattern.

• Interaction and multiscale mechanics
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• 제6권1호
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• pp.15-29
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• 2013

Phononic system composed of periodical elastic structures exhibit band gap phenomenon, and all elastic wave cannot propagate within the band gap. In this article, we consider one-dimensional binary materials which are periodically arranged as a 20-layered medium instead of infinite layered system for phononic system. The layered medium with finite dimension is subjected to a uniformly distributed sinusoidal loading at the upper surface, and the bottom surface is assumed to be traction free. The transient wave propagation in the 20-layered medium is analyzed by Laplace transform technique. The analytical solutions are presented in the transform domain and the numerical Laplace inversion (Durbin's formula) is performed to obtain the transient response in time domain. The numerical results show that when a sinusoidal loading with a specific frequency within band gap is applied, stress response will be significantly decayed if the receiver is away from the source. However, when a sinusoidal force with frequency is out of band gap, the attenuation of the stress response is not obvious as that in the band gap.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 학술대회 논문집
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• pp.399-403
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• 2005

In this paper, we analyze on the effect of RC filter to mitigate transient overvoltage on the high voltage induction motor fed by H-bridge cascaded 7-level inverter. The switching surge voltage becomes the major cause to occur the insulation failure by serious voltage stress in the stator winding of high voltage induction motor. The effect of switching surge appears more serious in high voltage induction motor than low voltage induction motor. Consequently, we demonstrated that the RC filter connected to the motor terminals greatly reduces the transient voltage stress md ringing. The results of simulation show the suppression of transient overvoltage at the motor end of a long cable. using EMTP

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.469-475
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• 2004

The transient analysis of delaminated smart composite laminates is studied using an improved layerwise laminate theory. The theory is capable of capturing interlaminar shear stresses that are critical to delamination. The presence of discrete delamination is modeled through the use of Heaviside unit step functions. Stress free boundary conditions are enforced at all fee surfaces. Continuity in displacement field and transverse shear stresses are enforced at each ply level. In modeling piezoelectric composite plates, a coupled piezoelectric-mechanical formulation is used in the development of the constitutive equations. Numerical analysis is conducted to investigate the effect of nonlinearity in the transient vibration of bimodular behavior caused by the contact impact of delaminated interfaces. Composite plates with delamination, subject to external loads and voltage history from surface bonded sensors, are investigated and the results are compared with corresponding experimental results and plates without delamination.

• 한국자동차공학회논문집
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• 제8권3호
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• pp.77-84
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• 2000

Nonlinear transient analysis is executed to obtain the temperature distribution, and to evaluate the thermal stress of brake drum by using FEA(finite element analysis). The result induces the reason why hair crack and the cause of drum failure occurs and the way how stress of drum decreases. The temperature of drum is in proportion to the drum thickness and it processes nonlinear changes at every points of drum. The higher bulk temperature raises, the more stress difference between inner surface and outer surface makes and the highest bulk temperature is at the corner section. It is necessary for the diminishment of the drum stress to make air flow, between drum and rim, move lively and use the materials of higher conductivity. The hair crack and the cause of drum failure seem to be started at the near corner section.

• 한국정밀공학회지
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• 제15권11호
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• pp.227-232
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• 1998

The purpose of this study is to develop a numerical method for analyzing the transient heat transfer and evaluating the residual stress. The analysis of heat transfer and thermal stress are carried out by three-dimensional finite element method. Thermal spraying is one of the most common surface coating techniques to be used for many applications. In order to improve the mechanical properties of flame-sprayed ceramic coating layer, the accurate and effective analysis of heat transfer and thermal stress is essentially required.