• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.161.1-161
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• 2001

Tire roller is one of the most useful machines for the road constructions site. In this research, we are trying to develop tire roller which is operated by hydraulic transmission system instead of mechanical one. Now, we are trying to design the controller of tire roller in order to improve performance. Our present system model is somewhat different from the actual experimental results. Therefore we would like to develop new accurate modeling through ARX model by system identification method with random inputs. In this paper, we applied it to the steering system only. Later we will apply it to the traction system and expand to the whole tire roller system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.535-539
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• 2001

The aim of this paper presents to develop a computer-aided design system for water gate on AutoCAD R2000system. The developed system has been written in AutoCAD and Visua ILISP with a personal computer, and is composed four modules which are the gate-lifter input module, guide-frame input module, template input module and upgrade module. Based on knowledge-based rules, the system is designed by considering several factors, such as width and height of a water gate, material, object of product and maximum depth of water. Employing the developed system enable the designer and manufactures of water gate to be more efficient in this field, and its potential capability for enhancement included FEM(Finite Element Method) and quotation system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.660-664
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• 1997

본 논문은 사출금형 설계를 위한 전문가 시스템의 개발에 관한 연구이다. 설계자가 오토케드 (AutoCAD)환경에서 금형부품 및 몰드베이스를 3차원 형상으로 나타낼 수 있으며 필요한 설계 데이터를 추가할수 있는 프로그램 개발에 있다. 주 프로그램은 C++를 사용하여 구축하였으며,금형부품 치수 및 몰 드베이스를 데이터베이스화 하였다. 주 프로그램과 오토캐드와 인터페이스를 하여 오토캐드 환경에서 자 유롭게 사용할 수 있도록 하였다. Pull-down menu와 Dialog box를 이용하여 금형 설계자가 금형의 각 부 품을 자유롭게 선정할 수 있으며, 각 단계별 선정된 금형부품은 즉시 나타나 설계자가 바로 확인 할 수 있도록 하였다. 이젝터 핀의 위치 및 크기를 자동적으로 나타낼수 있으며, 선정된 금형 부품 및 몰드베이 스는 2차원이나 3차원으로 나타낼 수 있다. 각각의 3차원 부품을 독립적으로 나타낼 수 있어 NC프로그램과 인터페이스가 가능토록 하였다.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.2
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• pp.68-74
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• 1998

In this work, we have been concerned with developing an intelligent mold design system for plastic injection molding on the AutoCAD. We have concentrated on building a viable environment, including a mold parts database and a menu-driven user interface. This provides a more interactive and interface for selection of optimal mold-base and mold parts in mold design system. This work presents a method which allows the designer to select the mold parts and mold-base directly within an AutoCAD environment. It can also automatically generate detailed 3D drawings of the mold parts and mold-base. The system shows its potential capability for future enhancement. Since the system is independent of the data, it could easily be extended to other mold-bases and mold parts. In addition, it can be linked to the molding analysis system by creating subtracted 3-D models.

• Smart Structures and Systems
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• v.11 no.6
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• pp.569-587
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• 2013

This paper evaluates the closed loop performance of the reaching law based discrete sliding mode controller with multisensor data fusion (MSDF) in real time, by controlling the first two vibrating modes of a piezo actuated structure. The vibration is measured using two homogeneous piezo sensors. The states estimated from sensors output are fused. Four fusion algorithms are considered, whose output is used to control the structural vibration. The controller is designed using a model identified through linear Recursive Least Square (RLS) method, based on ARX model. Improved vibration suppression is achieved with fused data as compared to single sensor. The experimental evaluation of the closed loop performance of sliding mode controller with data fusion applied to piezo actuated structure is the contribution in this work.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.5
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• pp.7-12
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• 2005

This paper presents several time series methods to analyze the chatter mechanics by using the power spectrum of these algorithms considering the cutting dynamics. In this study, several time series models such as AR(burg, forwardbackward, geometric lattice, instrument variable, least square, Yule Walker), ARX(1s, iv4), ARMAX, ARMA, Box Jenkins, Output Error were modeled and compared with one another. Finally, it was proven that time series modelings are also a desirable and reliable algorithm than the other conventional methods(FFT) for the calculation of the chatter mode in turning operation. Also, the spectrum of times series methods is a little bit more powerful than the FFT fer the detection of a high noisy and weak chatter mode. The radial cutting force Fy has been used for spectrum and chatter stability lobe analysis in this study.

• The Korean Journal of Mycology
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• v.10 no.4
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• pp.177-180
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• 1982

Gaeumannomyces graminis var. tritici was first isolated from rice in 1981. Sheath rot of rice seedling in box culture for machine transplanting was produced by artificial inoculation of the causal organism. Especially sheath rot was developed from crown to leaf sheath above water level. Perithecia were usually formed in dead leaf sheaths and in PDA culture. They were black, globose, and immersed with obliquely erumpent neck. Asci were unitunicate with an apical ring and contained 8 spores. Ascospores were hyline, slender, $80{\sim}140\;um$ in length. Each spore showed $3{\sim}4\;septa.$ Based on morphological and cultura characteristics, the isolate from seeds was identified as Gaeumannomyces graminis (Sacc.) Arx & Olivier tritici J. Walker.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.335-339
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• 1998

This paper presents a closed loop identification algorithm in time domain. This algorithm can be used for identification of unstable system and for model validation of system which is difficult to derive analytical model. In time domain, projection filter, which projects a finite number of input output data of a system into its current space, is used to relate the state space model with a finite difference model. Then recursive relations between the Markov parameters and the ARX model coefficients are derived to identify the system, controller and Kalman filter Markov parameters recursively, which are finally used to identify the system, controller and Kalman filter gains. The NASA LAMSTF is used to validate the algorithms developed.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.203-206
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• 2002

동적 시스템의 동정은 시스템의 관측된 데이터를 가지고 동적 모델의 수학적 모델을 찾는 문제를 다루는 것이다. 기존의 고전적인 방법으로는 차분 방정식(ARX 또는 ARMAX) 또는 상태 공간 표현에 관한 계수들을 추정하기 위해서 회귀 기법 등을 사용하였다. 그러나 이러한 고전적인 방법들은 파라미터가 비선형이고, 실세계 문제에서 모델링 오차나 측정 잡음을 수반하게 되면 탐색의 어려움을 가지게 된다. 따라서 이러한 문제점을 극복하고자 퍼지 이론이나 신경망 이론 둥이 이용되었으나 본 논문에서는 비선형 동적 시스템의 파라미터 동정에 최근 복잡한 최적화 문제를 해결하는 도구로 점점 관심을 받고 있는 유전 알고리즘을 동정 알고리즘으로 제안하고, 비선형 동적 시스템의 파라미터 동정에 유전 알고리즘을 응용한 몇 가지 예를 제시하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.410-418
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• 1999

This paper describes the use of residual and parameter identification methods for fault detection in an air handling unit. Faults can be detected by comparing expected condition with the measured faulty data using residuals. Faults can also be detected by examining unmeasurable parameter changes in a model of a controlled system using a system identification technique. In this study, AutoRegressive Moving Average with seXtrnal input(ARMAX) and AutoRegressive with eXternal input(ARX) models with both single-input/single-input and multi-input/single-input structures are examined. Model parameters are determined using the Kalman filter recursive identification method. Regression equations are calculated from normal experimental data and are used to compute expected operating variables. These approaches are tested using experimental data from a laboratory's variable-air-volume air-handling-unit.