• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.177-180
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• 2001

A decoupled, wide-band, perfectly magnetically conductor(PMC)-backed air waveguide antenna is designed and constructed for the use of the continuous electromagnetic wave ground penetrating radar in the frequency range from 200MHz to 600MHz. Two planar dipoles are located inside air slab covered by PMC on the top side and separated by an air gap from the bottom ground interface. The coupling between the transmitting and the receiving dipoles is calculated by less than -60dB over the frequency from 200MHz to 600MHz.

• 한국생산제조학회지
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• 제5권2호
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• pp.63-72
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• 1996

In order to regulate the cutting force at a desired level during peripheral end milling processes a feedrate override Adaptive Control Constraint (ACC) system was developed. The feedrate override function was accomplished through a development of programmable machine controller (PMC) interface technique on the NC controller, Nonlinear model of the cutting process was linearized as an adaptive model with a time varying process parameter. An integral type estimator was introduced for on-line estimation of the cutting process parameter, Zero order hold digital control methodology which uses pole-assignment concept for tuning of PI controllers was applied for the ACC system. Performance of the ACC system wsa confirmed on the vertical machining center equipped with fanuc OMC through a large amount of experiment.

• 한국전자파학회논문지
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• 제29권10호
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• pp.805-810
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• 2018

산란파 감소 등의 목적으로 PEC 상에 코팅된 매질은 임피던스 경계조건을 사용하여 효과적으로 모델링되며, Yan이 제안한 SDIE 방법을 이용하여 임피던스 경계조건 MLFMM 방법을 쉽게 구현할 수 있다. SDIE MLFMM 방법은 매질의 임피던스가 불균일한 경우에도 적용될 수 있으나, PEC 또는 PMC 영역을 포함할 경우에는 결과가 부정확해질 수 있다. 본 논문에서는 Yan의 SDIE MLFMM 방법을 변형하여 PEC 또는 PMC 영역을 포함하는 불균일 임피던스 매질을 효율적으로 해석할 수 있는 방법을 제안하고, 그 정확도를 시뮬레이션으로 검증한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.411-416
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• 1993

In order to achieve computer-oriented control and automation of manufacturing processec, a distributed NC (DNC_) system was developed for FMS under the Windows environment. The DNC system consists of conventional DNC, PMC interface and tool management modules. Real-time system conditon monitoring and control fuctions required for machine tools and machining processes were accomplished by developing a PMC interface module called MMC board. Tool condition monitoring and management was performed by the developed tool management module composed of a tool setting probe and softwares. Performance of the DNC system was confirmed on the horizontal and the vertical type machining center equipped with FANUC OMC for the large amount of experiments.

• 한국공작기계학회논문집
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• 제17권3호
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• pp.101-107
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• 2008

A composite mechanics for discontinuous fiber reinforced polymer matrix composites(PMC) is analysed in order to predict fiber axial stresses. In continuum approach. frictional slip which usually takes place between fibers and polymers is accounted to derive PMC equations. The interfacial friction stress is treated by the product of the coefficient of friction and the compressive stress norma1 to the fiber/matrix interface. The residual stress and the Poisson's contraction implemented by the rule of mixture(ROM) are considered for the compressive stress normal to the fiber/matrix interface. In addition. the effects of fiber aspect ratio and fiber volume fraction on fiber axial stresses are evaluated using the derived equations. Results are illustrated numerically using the present equations with reasonable materials data. It is found that the fiber axial stress in the center region shows no great discrepancy for different fiber aspect ratios and fiber volume fractions while some discrepancies are shown in the fiber end region.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1993년도 추계학술대회 논문집
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• pp.321-327
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• 1993

In order to maintain the cutting force at a desired level during peripheral end milling processes in spite of variation of the depth of cut and other machining conditions, a feedrate override. Apaptive Control Constraint (ACC) system are developed. Feedrate override was accomplished by a developed MMC board and PMC interface techniques. Nonlinear model of the cutting process was linearized as an adaptive model with time varying paramrters. Integral type estimators were introduced for on-line identification of cutting and control parameters in peripheral and milling processes. Zero Order Jold (ZOH) type degital control methodology which uses pole-placement concepts was applied for the ACC system. Performance of the developed ACC system was confirmed on the vertical machining center equipped with FANUC OMC for a large amount of experiment

• 한국산업융합학회 논문집
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• 제11권3호
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• pp.135-140
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• 2008

This paper researched about Development Cutting Tool User Defined Module Based(PMCUDMS) on Simulation that was able to adapt themselves to rapid development of software and hardware to adopt. It is basic research that develops a scheme whereby technic make property. This paper theorized about to realize Cutting Tool User Defined Module Based on Simulation which is developing CNC Software flows from building Windows XP operating system's image that is possible realtime acting and multitasking to correct. And Cutting Tool User Defined Module Based on Simulation component which was consisted of basis OS, NC Code parser, Servo Motor Control, Simulator, Man-Machine Interface.

• 대한기계학회논문집A
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• 제25권8호
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• pp.1173-1182
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• 2001

Recent noticeable advances of CNC machine tools have considerably improved productivity and precision in manufacturing processes. However, in the respect of productivity some defects still remain because selection of machining conditions entirely depends on the experiences of programmers. Usually, machining conditions such as feed rate and spindle speed have been selected conservatively by considering the worst cases, and it has brought the loss of machining efficiency. Thus, the improvement of cutting force controller has been done to regulate cutting force constantly and to maximize feedrate simultaneously in case that machining conditions change variously. In this study, sliding mode control with boundary layer is applied to milling process for cutting force regulation and in a commercial CNC machining center data transfer between PC and PMC (programmable machine controller) of CNC machine is done using a standard interface method. And in the cutting force measurement, an indirect cutting force measuring system using current signal of AC servo is adopted in order not to use high-priced equipment like tool dynamometer. The purpose of this study is to maximize the productivity in milling process, thus its results can be applied to cases such as rough cutting process.