• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권3호
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• pp.238-243
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• 2009

This paper present same thodology for the classification of power system voltage stability, the trajectory of which to instability is monotonic, using an interior point method based support vector machine(IPMSVM). The SVM based voltage stability classifier canp rovide real-time stability identification only using the local measurement data, without the topological information conventionally used.

• 한국정밀공학회지
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• 제15권5호
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• pp.34-42
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• 1998

This paper describes an analysis of measuring error of on the machine measuring(OMM) system which directly measures machined surface dimensions using scanning probe on a CNC milling machine. 21 inch TV shadow mask mould clamped to a pallet was measured using PTP(point to point) measuring algorithm in OMM system and the results were compared with those using coordinate measuring machine(CMM). The OMM error was evaluated by probe error, stylus contact error, center shift error, repeatability, work-piece clamping error and etc. The results show that elastic deformation of the pallet is most affecting factor on the measuring error, thus pallet design and clamping method need very careful cosiderations.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 춘계학술대회 논문집
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• pp.73-77
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• 1997

This paper describes the analysis of measuring error of on the machine measuring(OMM) system which can directly measure the three dimensional machined free surface dimension using scanning probe on milling machine. 21 inch TV shadow mask mould was measured using PTP(point to point)measurement algorithm at pallet clamped and unclamped state on OMM system, and using coordinate measuring machine(CMM) one after another. The OMM system was evaluated probe error, stylus contact error, center shift error, repeatability and so on. Consequencely, the conclusion derived that elastic displacement of pallet had effect on measuring error mainly, and pallet design and setup method would be important.

• 전기학회논문지
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• 제63권12호
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• pp.1747-1751
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• 2014

Interlocking system along with point machine for efficient route control secures safety of train operation by interchanging information each other. However, various types of interlocking system and point machine operating on bender specific interface bring obstacles to effective maintenance and safety. In this paper, we have investigated on interface methods to suggest standard interface module applicable to various operating system

• 연구논문집
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• 통권31호
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• pp.101-112
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• 2001

A Twisting machine is to twist yarns for improving yarn stiffness. After twisting yarns, the twisting machine is winding yarn at a bobbin. Traverse cam is main part of winding yarn part. In other to improve twisting machine performance and stability, improve traverse cam part. Original displacement curves of traverse cam has two problems. One is that displacement curve has a vertex point the other is that velocity curve is discontinue point. So that, in this paper proposes a modified displacement curves of traverse cam and new shape design method of the traverse cam using the relative velocity method[1]. The relative velocity method calculates the relative velocity of the follower versus the cam at a center of roller, and then determines a contact point by using the geometric relationship and the kinematical constraints. Finally, we present to compare two designed cam. One is designed using original displacement curves the other is using modified displacement curve.

• 스마트미디어저널
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• 제6권2호
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• pp.33-41
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• 2017

철도 선로전환기는 열차의 진로를 현재의 궤도에서 다른 궤도로 제어하는 장치이다. 선로전환기의 노후화로 인한 이상 상황은 탈선 등과 같은 심각한 문제를 발생할 수 있기 때문에, 선로전환기의 적절한 교체시기를 결정하는 것은 매우 중요하다. 본 논문에서는 국내 철도 현장에서 획득한 선로전환기의 전류신호로부터 다차원 데이터 큐브를 구성하고 OLAP(On-Line Analytical Processing) 분석을 통하여 체계적으로 "교체가 필요한 데이터"와 "교체 시점이 아닌 데이터" 집합을 정제하여 분류하였다. 또한 선로전환기의 교체시기 탐지 문제를 이진 분류 문제로 해석하여 이진 분류기의 대표적 모델인 SVM(Support Vector Machine)을 탐지기로 설계함으로써 선로전환기의 노후화에 따른 적절한 교체시기를 탐지하는 시스템을 제안한다. 이때, 입력되는 전류 신호를 DWT(Discrete Wavelet Transform)와 PCA(Principal Components Analysis) 기법으로 고차원의 특징벡터 신호를 정보의 손실을 최소화하면서 저차원의 특징벡터로 변환한다. 실제 국내에서 운행 중인 선로전환기의 이상상황 정보가 포함된 대규모의 전류 신호를 이용하여 제안하는 시스템의 성능을 실험적으로 검증한 바 98%를 넘는 탐지 정확도를 확인하였다.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.222-233
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• 1998

A 4-point pure bending res machine is developed the evaluate the pure vending moment-rotation properties of the thin-walled tubes without imposing shear and tensile forces. The moment-rotation properties of the thin-walled tubes are measured up to and beyond collapse with the pure bending test machine. The test results are compared with those of finite element analyses and existing analytical solution.

• 산업공학
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• 제11권1호
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• pp.199-205
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• 1998

This paper describes the development of on-the-machine measuring(OMM) system which can directly measure the two and three dimensional machined accuracy using a scanning probe in milling machine. Two algorithms, NC program based continuous path(CP) measurement and CAD data assisted point to point(PTP) measurement, are developed for three dimensional measurements, with consideration of the characteristics of the scanning probe. The algorithms are used to develop an auto measuring system. The delveloped system is compared with the CMM (Coordinate Measuring Machine) in terms of accuracy and repeatability. The OMM system is expected to realize measurement time reduction and hence result in high productivity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1196-1198
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• 2004

This paper represents the improvement of floating point operation for AC servo motor controller based on fixed point operation DSP. TMS320F2812 has fixed point operation processing structure. The controller parameters are modified to the digitized data by scaling the original parameters. TMS320F 2812 is a 32-bit processor, and it could have enough accuracy to got the digitized data this procedure is implemented and the experiments controling a AC servo system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.98-100
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• 2005

DSPs used at motor control are usually fixed point processor. They need scaling because they cannot excute floating point calculation. Scaling for floating point calculation makes the DSP's speed down, complex coding and etc. Therefore the IQ math is adopted. IQ math makes the fixed point processor possible to calculate the floating point math. In addition, IQ math can reduce memory usage and be more faster than that without IQ math. It seems that IQ math is appropriate in motor position control. In comparison of the position calculation between the IQ math, math function and the sine table, the method using IQ math is superior than other methods.