• 한국철도학회논문집
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• 제6권1호
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• pp.41-48
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• 2003

Most of people spends their times in indoor about 85% of a day. Thus, indoor is more serious than outdoor concerned with the health. We discussed comfortableness in a railroad electric rolling stock, and focused on temperature and humidity. Electric rolling stock is one of major public transportation system because of an increasing in population and heavy traffic problems. The passengers are under the influence of indoor air quality such as air temperature, relative humidity and air velocity. Ventilation system in electric rolling stock should be designed for the health and comfort. One of the main aims is to create an acceptable thermal environment without draught problem. The draught sensation increases when the air temperature decreases and the air velocity increases. Airflow in electric rolling stork is turbulent. Temperature and humidity gradients in electric rolling stock have been studied. And, the difference between mean temperature and rotative humidity measured at 0.7, 0.9, 1.2, 1.7m above the floor. It has been found that temperature and relative humidity with large fluctuations caused more draught complaints.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.620-623
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• 1996

POSCO has been developed a general purpose dynamic simulator of the hot strip steel mill. The simulator is a tool for developing the process control system in an industrial system solution business, by making the most use of control and simulation techniques fostered in steelmaking business. This simulator has, not only a powerful numerical analysis function, but an easy-to-use graphic user interface which readily enables to simulate dynamic system. This paper presents the features of the simulator and steel rolling process simulator as its application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 B
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• pp.671-673
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• 1999

In order to cope with the occurrence of abnormal operation, rotatory condition monitoring system for guide roller of finishing train in wire rolling has been developed. In this study, proximity sensor and its holding devices that could overcome severe in-situ measurement conditions was designed and MMI software using C++ was programmed. Performance of the developed system turned out to be good enough as results of in-line test for POSCO #3 wire rolling mill. It is expected to contribute to prevent the cobble and the grade-down of products caused by the abnornormal operation of guide rollers.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.117-120
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• 2001

In hot roiling process, new rolling mills have been apapted to strip rolling but we can usually experience the problem of snaking of strip. This phenomenon was arisen by nonsymmetric rolling and on-centering and cambering of a strip and other mill conditions. Three dimensional analysis for strip rolling predicted the influence of nonsymmetric rolling, off-centering and pair crossing system This study evaluated the fundamental characteristics of snaking of a strip to optimize the operating condition for trouble free rolling.

• 한국정보통신학회논문지
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• 제4권5호
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• pp.951-961
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• 2000

압연기의 기계적인 이상을 사전에 알아내는 압연기 베어링 고장-진단 시스템은 예측하지 못하는 압연 공정의 중단으로 인하여 발생하는 큰 피해를 사전에 막기 위해서 매우 중요한 시스템이다. 그러나 압연기의 동적 거동은 비선형 특성이 매우 강하기 때문에 압연기에서 사전에 고장 예측 정보를 제공하는 것은 매우 어렵다. 본 논문에서는 웨이브렛을 이용한 압연기의 고장 진단 방법을 제안하였으며 제안된 방법은 온라인으로 압연기에서 진동 신호를 실시간으로 측정하여 웨이브렛을 이용하여 패턴을 분석하고 분석된 결과로부터 고장 특징 정보를 얻었다. 얻어진 데이터를 이용하여 압연기 베어링을 진단하는 뉴로 퍼지 모델을 설계하고 수치적인 시뮬레이션을 통하여 그 타당성을 입증하였다.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.139-145
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• 2000

The mechanism of the inner resistance in a rubber crawler system has been investigated to reduce the power requirement (Kitano et al. 1994). The rolling resistance of the track roller, which is one of the major inner resistances, was measured for seven different vertical loads. The rolling resistance changed periodically and could be classified into three types. In case of the vertical load less than 500N, the rolling resistance was almost constant. For the vertical load greater than 500N, the maximum value of the rolling resistance increased. Further more in case of the vertical load greater than 1200N, negative resistance appeared. Analytical simulation of the travel resistance based on experimental results and static equilibrium equations derived from three-dimension mechanical model for the rubber crawler system. It was found that the simulation method was carried out to evaluate the travel resistance occurred by the rolling resistance of the track roller. The rolling resistance for each track roller arrangement and effects of the lug phase in the right and left rubber crawler could be estimated quantitatively.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1642-1649
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• 2010

At present, KORAIL is in the middle of renovating. All steps exert great effort at cost reduction and a profit improvement. Especially to improve maintenance method and inspection period at the rolling-stock division lots of research is under progress. Daily inspection of rolling stocks is to operate the rolling stock normally. Daily inspection items are driving control device, coupling device, brake system, water system and air conditioning system, electrical system etc. Half of the maintenance manpower are inputted at daily inspection. Strengthens the quality and optimize the proportion of daily inspection are urgent problem. Daily inspection period extension aim is as follows. KTX from 3,500km to 5,000km, passenger car from 1st to 3,500km, new style electric locomotive from 2nd to 5,000km, the diesel locomotive is 2,800km from 1,200km. In this paper, the optimal daily inspection period and methods are considered including expected problem and counter measures.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.88-97
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• 1999

In this study, a systematic approach for roll pass design in bar rolling was studied. To minimize the trial and errors in the process design, a roll CAD system and a FE analysis system were combined. Based on the system, a methodology for roll pass design by FEM was studied. At first, designed process was compared with the FE analysis results and process redesign based on the FEM results was performed to obtain the specified final geometry. Then, empirical formula for roll speed set-up was compared with the FE analysis results. Further study on various simulations for bar rolling will help in making up for the inaccuracy in the currently used empirical roll speed rules. In addition, verification of the accuracy of the FE analysis system must be performed using experimental data in the industry.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2242-2249
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• 2006

The rolling piston type rotary compressor has been widely used for refrigeration and air-conditioning systems due to its compactness and high-speed operation. The present analysis is part of a research program directed toward maximizing the advantages of refrigerant compressors. The study of lubrication characteristics in the critical sliding component is essential for the design of refrigerant compressors. Therefore, theoretical investigation of the lubrication characteristics of a rotary compressor being used for refrigeration and air-conditioning systems was investigated. The Newton-Raphson method was used for a partial elastohydrodynamic lubrication analysis between the vane and the rolling piston of a rotary compressor. The results demonstrated that the vane thickness and the center line position of the vane significantly influenced the friction force and the energy loss between the vane and the rolling piston.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1476-1479
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• 1996

발전설비나 자동차 그리고 항공우주분야에 사용되는 각종 bearing, 원형부품들에 사용되는 ring을 생산하는 방법중, 가장 효과적이고 경제적인 방법은 ring rolling (ring 압연)이다. 이 방법은 직경 50cm에서 2m이상의 원형 ring을 연속적으로 짧은 시간내에 (한 ring당 약 1분) 생산 가능하다. 이제까지의 수학적 모델을 사용한 제어시스템은 ring의 단면적이 사각형인 제품에는 최소한의 오차로 생산 가능하였으나, plant의 생산성과 제품의 다양성을 위하여 ring의 단면적이 복잡한 것을 생산시에는 문제점이 노출되었다. 왜냐하면 기존의 수학적모델이 roll gap 또는 metal forming zone에 근거하여 modelling하였기 때문이다. 본 논문에서는, 이러한 문제점을 고전적인 수학적 모델을 기초로한 adaptive control system의 방법대신에, 축적된 control system설계와 운용 경험을 이용하여 설계한 퍼지제어기 및 그것의 실적용 그리고 그 결과를 소개한다. 실적용 결과는, 제조된 단면적이 상대적으로 복잡한 bearing의 형상이 (filling grad)이 제어기의 제어정도 판단기준이었는데, 99.5%의 형상도를 보임으로서 industry에서 요구하는 제품기준을 만족시켰다. 또한 짧은 제어기 설계 및 on-line optimization 기간 또한 이 제어기의 장점이었다.