• 전기학회논문지
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• 제56권4호
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• pp.730-738
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• 2007

As well known when the linear machine is operated between two points repeatedly under positioning control, there are various positioning error at the moment of zero speed owing to the non-linear disturbance like as unpredictable friction force. To remove this positioning error, a simple least order disturbance observer is introduced and is actually implemented in this study. Due to this simple algorithm the over-all machine system can be modified to simple arbitrary given one-mass load without any disturbance. So, the total construction process for positioning control system is much easier than old one. Moreover, to generate a proper effective position profile with the limited actual machine force, a very powerful on-line mass identification algorithm using the load force estimator is presented. In the proposed mass identification algorithm, the exact load mass can be calculated during only one moving stage under a normally generated position profile. All presented algorithm is verified with experimental result with commercial linear servo machine system.

• 응용통계연구
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• 제35권3호
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• pp.335-346
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• 2022

통계적 공정관리에서 프로파일 관리도란 다수의 품질 특성치 간 함수관계의 변화를 탐지하는 것을 말한다. 두 변수 간 선형의 관계가 있는 경우, 선형 프로파일을 가정하고 절편과 기울기가 일정한지 모니터링한다. 이때 선형 프로파일에 관한 대부분의 기존 연구에서는 모든 프로파일에서 설명변수의 관측치가 동일하다고 가정한다. 그러나 프로파일마다 설명변수의 값이 랜덤하게 관측되는 경우도 존재한다. 본 논문에서는 단순 선형 프로파일 모니터링에서 설명변수가 프로파일마다 랜덤하게 관측된다는 가정하에 기존의 방법을 확장 적용하고자 한다. 모의실험을 통해 제안한 방법의 탐지 성능을 확인하고 네트워크 침입 탐지 알고리즘 성능을 비교하기 위한 NSL-KDD 데이터를 이용하여 제안된 침입 탐지 결과를 비교해 보았다.

• 전력전자학회논문지
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• 제12권3호
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• pp.221-233
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• 2007

본 논문에서는 고성능 단축 선형전동기에 적용할 수 있는 최단시간 위치 패턴 알고리즘에 대하여 논한다. 근래 들어 LCD/PDP 및 반도체 산업이 발달함에 따라 대형의 고성능 위치제어 시스템에 대한 요구가 높아지고 있으며 이러한 시스템에서는 공정 주기의 단축을 위하여 시간요소를 최소화시킨 최적 위치 패턴이 반드시 필요하다. 특히 반도체 산업 분야에서는 공작기계 분야와 달리 3차원 입체 위치 패턴보다는 단축 패턴에 대한 수요가 비교적 많은 편이다. 본 연구에서는 가속도가 사다리형인 위치 패턴을 기본으로 하여 연구를 진행하였으며 위치 및 시간을 변수로 고려한 패턴 분석을 통하여 최단시간에 목적하는 위치에 도달하기 위한 패턴을 비교적 간단히 구현할 수 있음을 보이고 이를 시뮬레이션 및 간이 실험으로 구현 가능성을 입증하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 추계 학술대회논문집
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• pp.121-126
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• 1998

A numerical optimization procedure is developed to find the inlet velocity profile that yields the most uniform epitaxial layer in a vertical MOCVD reactor. It involves the solution of fully elliptic equations of motion, temperature, and concentration; the finite volume method based on SIMPLE algorithm has been adopted to solve the Navier-Stokes equations. The overall optimization process is highly nonlinear and has been efficiently treated by the sequential linear programming technique that breaks the non-linear problem into a series of linear ones. The optimal profile approximated by a 6th-degree Chebyshev polynomial is very successful in reducing the spatial non-uniformity of the growth rate. The optimization is particularly effective to the high Reynolds number flow. It is also found that a properly constructed inlet velocity profile can suppress the buoyancy driven secondary flow and improve the growth-rate uniformity.

• 대한설비공학회지:설비저널
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• 제17권4호
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• pp.382-394
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• 1988

Dynamic characteristics of thermally-forced stratification process in a square enclosure with a linear temperature profile at the side walls have been investigated through flow visualization experiment and numerical analysis. The experiment was performed on air with the Rayleigh numbers of order $10^5$. A particle tracer method is used for the flow visualization and to obtain a sudden linear temperature profile at the side walls copper blocks which already have a linear temperature profile are come into contact with the thin copper plates of the test section. Immediately a meridional circulation is developed and heat transfer takes place from the wall to the interior region by circulation of fluid and finally a thermal stratification is achieved. In the numerical study, QUICK scheme for convective terms, SIMPLE algorithm for pressure correction, and the implicit method for the time marching are adopted for the integration of conservation equations. Comparison of flow visualization and numerical results shows that the developing flow patterns are very similar in dynamic nature even though there is a time lag due to the inevitable time delay in setting up a linear temperature profile. For high Rayleigh numbers, the oscillatory motion is likely to take place and stratified region is extended. However, initial temperature adjustment process is much slower than that for low Rayleigh numbers.

• 한국소음진동공학회논문집
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• 제24권6호
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• pp.437-443
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• 2014

Vibration testing is conducted for evaluate the fatigue resistance of responsible system over excitation situations and two kinds of vibration profiles, harmonic or random, are widely used in engineering fields. Harmonic excitation profile is adequate for the rotating machinery that is primarily exposed to the orderly excited force subjected for a rotating speed; Random profile is suitable for the non-stationary vibration input, that is a ground excitation for example. Recently, the sine on random(SOR) testing method was sometimes considered to represent the real excitation conditions since the measured response signals of a target system, expecially for moving mobility, shows usually a mixture of them. So, it is important to understand the accumulated fatigue damage over different excitation patterns, harmonic and/or random, to determine the efficient vibration profile of a target system. A uniaxial vibration testing with a notched simple beam was introduced to evaluate the fatigue damage for different excitation profiles and the best choice of vibration profile was concluded from those comparison of calculated fatigue damages.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.340-345
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• 2014

Vibration testing is conducted for evaluate the fatigue resistance of responsible system over excitation situations and two kinds of vibration profiles, harmonic or random, are widely used in engineering fields. Harmonic excitation profile is adequate for the rotating machinery that is primarily exposed to the orderly excited force subjected for a rotating speed; Random profile is suitable for the non-stationary vibration input, that is a ground excitation for example. Recently, the sine on random (SOR) testing method was sometimes considered to represent the real excitation conditions since the measured response signals of a target system, expecially for moving mobility, shows usually a mixture of them. So, it is important to understand the accumulated fatigue damage over different excitation patterns, harmonic and/or random, to determine the efficient vibration profile of a target system. A uniaxial vibration testing with a notched simple beam was introduced to evaluate the fatigue damage for different excitation profiles and the best choice of vibration profile was concluded from those comparison of calculated fatigue damages.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 2005년도 춘계학술발표대회 논문집
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• pp.3-8
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• 2005

The robot systems are widely used in the welding manufacturing. The essential tasks to operate the welding robot are the acquisition of the position and/or shape of the parent metal. For the seam tracking or the robot automation, many kinds of contact and non-contact of the system which monitors the shape of the welding part is described. This system uses the line-type structured laser diode and the visual sensor. It includes the correction of radial distortion which is often found in the image from the camera with short focal length. Direct Linear Transformation (DLT) is used for the camera calibration. The three dimensional shape of the parent metal is obtained after simple linear transformation. Therefore, the system operates in real time. Some experiments are carried out to evaluate the performance of the developed system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.285-286
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• 2006

The essential tasks to operate the welding robot are the acquisition of the position and/or shape of the parent metal. For the seam tracking or the robot automation, many kinds of contact and non-contact sensors are used. Recently, the vision sensor is most popular. In this paper, the development of the system which measures the profile of the welding part is described. The total system will be assembled into a compact module which can be attached to the head of welding robot system. This system uses the line-type structured laser diode and the vision sensor It implemented Direct Linear Transformation (DLT) for the camera calibration as well as radial distortion correction. The three dimensional shape of the parent metal is obtained after simple linear transformation and therefore, the system operates in real time. Some experiments are carried out to evaluate the performance of the developed system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1069-1070
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• 2006

This study is concerned with the control system design using Labview Simulation Interface Toolkit and Matlab/simulink combined system for an application to the personal rapid transit system which has very short headway, requiring accurate speed control to avoid the impact between the vehicles. A simple equation of motion for a vehicle which is activated on the linear motor is introduced. A speed profile that should be tracked by a rear vehicle is produced based on the state information of the two vehicles(the preceding vehicle and the rear vehicle). The speed profile tracking control system is designed by Matlab/simulink. The simulation results show that the proposed control system is effective to evaluate the speed tracking performance.