• 동력기계공학회지
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• 제3권1호
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• 산업경영시스템학회지
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• 제18권36호
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• pp.297-306
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• 1995

An automatic transfer line consists of several stages(groups of stations) in series into one system by a common transfer mechanism and a common control system. In this system losses of the efficiency are evidenced in periods where a stage is forcod down- starved or blocked. The efficiency of an automatic transfer line can be improved by providing buffer storages between a stage or the length of line common senses there are several critical factors, system configurations relative position, and buffer capacity allocations in automatic transfer line are considered with a point of view production rates, average stock, and mean delay. The propose of this paper is to provide the robust designs by Taguchi method which improve the efficiency of four-stage transfer line.

• 한국전자파학회논문지
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• 제14권4호
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• pp.377-383
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• 2003

동(copper) 케이블을 이용한 xDSL 초고속서비스가 널리 보급됨에 따라 외부 전자파에 의한 통신케이블의 전자파 결합특성을 해hi하기 위해 케이블 쉴드층의 전달임피던스가 중요하게 되었다. 본 논문에서는 xDSL 서비스를 제공하기 위해 사용되는 대표적인 형태의 통신케이블에 대해 IEC 96-1의 line injection method를 이용하여 전달임피던스를 측정하였다. 또한 injection line의 위치, 내부 도체의 위치가 전달임피던스에 어떻게 영향을 주는지를 분석하였으며, 이를 근거로 통신케이블의 전달임피던스 특성 모델을 제시하였다.

• 제어로봇시스템학회논문지
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• 제15권10호
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• pp.982-987
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• 2009

On the controller switching time, even though on-line/off-line controller outputs are the same, a problem which deteriorates the performance of bumpless transfer can happen in case that any discrepancy between the two controller inputs is transferred directly to the controller output. In this paper, we analyze the cause of that phenomenon in existing research results and propose a new method which improves that problem. In order to solve this problem, the off-line controller is augmented to an anti-windup structure and an improved bumpless transfer method is derived by using the changed input of the off-line controller instead of the plant input. We exemplify the performance of the proposed method by comparing with the performance of the existing method via numerical examples.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.267-271
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• 1996

In this study, performance improvement of the inverse modeling as the on-line control method for the estimation, control experiment is performed. As the modeling errors is occurred in duct system arbitrarily, a case using the filtered-x LMS algorithm only as the control method, a case using tile inverse modeling method only and a case using the inverse modeling with the adaptive line enhancer are compared. The estimation errors between real secondary path transfer functions and the estimated and the control performances of primary noises with these estimated transfer functions are compared.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1412-1415
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• 1996

In this paper, a new identification method of the cascade control system is proposed which can overcome the weak points of Krishnaswamy and Rangaiah(1987)'s method. This new method consists of two steps. One is on-line process identification using the numerical integration to approximate the two process dynamics with a high order linear transfer function. The other is a model reduction technique to derive out low order transfer function(FOPTD or SOPTD) from the obtained high order linear transfer function to tune the controller using usual tuning rules. While the proposed method preserves the advantages of the Krishnaswamy and Rangaiah(1987)'s method, it has such a simplicity that it requires only measured input and output data and simple least-squares technique. Simulation results show that the proposed method can be a promising alternative in the identification of cascade control systems.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.283-287
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• 1996

The exhaust noise reduction of automobile with the active muffler is experimentally investigated. The control algorithm is the filtered-x LMS algorithm and the inverse algorithm with the adaptive line enhancer. Also, the control efficiency is increased with synthesized second harmonic engine frequency. In the experiment, the active muffler is applied to the end of exhaust system in automobile and the control with on-line secondary path modeling method(inverse algorithm) is compared the control of off-line secondary path modeling method. As secondary path transfer functions are changed, the experimental results show that the control performance with on-line method is more efficient than that with off-line method in the exhaust noise reduction of automobile.

• 한국광학회지
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• 제9권6호
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• pp.396-402
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• 1998

광학계의 결상성능평가는 optical transfer function(OTF)을 측정하는 것이 표준적인 방법으로 사용되고 있다. 그러나, 대량 생산되는 광학계의 경우에서는 측정의 편리함 때문에 test pattern을 투영하여 contrast를 검사하는 방법도 많이 사용되고 있다. 본 연구에서는 회절결상이론을 사용하여 주기적 line-space pattern에 대한 contrast transfer function(CTF)을 계산하는 프로그램을 개발하고, C­계수와 Zernike 다항식으로 표현되는 3차 파면수차에 의한 광학계의 modulation transfer function (MTF)과 CTF 변화를 비교, 분석하였다.

• 한국레이저가공학회지
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• 제2권3호
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• pp.52-61
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• 1999

The laser induced forward transfer(LIFT) technique employs a pulsed laser to transfer parts of a thin metal film from an optically transparent target onto an arbitrary substrate in close proximity to the metal film on the target. In this work, a two-step method, the combination of LIFT process, in which a Au film deposited on the $Al_2$O$_3$ substrate by Nd:YAG laser and subsequent Au electroless metal plating on the by LIFT process generated Au seed, was presented. The influence of laser parameters, wavelength, laser power, film thickness and overlap ratio of pulse tracks, on the shapes of deposit and conductor line after electroless plating is experimentally studied. As a results, the threshold power densities for ablation, deposition and metallization were determined and comparison of threshold value between the wave length 1064nm and the second harmonic generated 532nm. In odor to determine a possible application in the electronic industry, a smallest conduct spot size, line width and isolated line space were generated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1996년도 춘계학술대회논문집; 부산수산대학교, 10 May 1996
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• pp.316-321
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• 1996

The authors has developed the transfer influence coefficient method(TICM) which is an algorithm for the analysis of vibration suitable for a personal computer and applied to many structures such as straight-line beam, plate and shell structures. But TICM can't be applied to the closed loop system and is required extremely much time on the computation of complicate and large structures. Therefore, we now suggest the transfer stiffness coefficient method(TSCM) overcoming these two problems, which consists on the concept of the substructure synthesis method and transfer influence coefficient method. TSCM is formulated for the free vibration analyses of a straight-line distributed beam structure and confirmed by the results of numerical computation to the numerical high accuracy and the high speed.