• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.57-65
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• 1999

This document illustrates the way to control of coiling temperature(CTC) of stip tail part in minimill process. The coiling temperature (CT) is very important fact in hot rolling process because the mechnical properties of strip depend on it. In mini-mill pocess, the speed pattern of rolling is different from that of conventional hot rolling. We have a lot of difficulties in controlling the coiling temperature at strip tail part, because after the strip tail is passed out the final stand, it's impossible to control the coiling temperature by using coiling speed. So we have CT deveiation in this gauge, about 160$^{\circ}C$ below in comparison with target CT. It's clear that deviation of mechanical properties(tensile strength, vield ratio etc) of strip to direction of length is so large, so we could not produce middle carbon steel, like this temperature condition. New coiling temperature control of strip especially in strip tail was developed. An innovative method for calculate the deceleration speed of strip tail has been implemented in CTC program, so called

• 동력기계공학회지
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• 제19권4호
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• pp.24-29
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• 2015

This paper designs a looper-tension controller for strip top-tail parts in hot strip finishing mills. A three-degree linear model of the looper-tension system is derived by a Taylor's linearization method, where the actuator's dynamics are ignored because of their fast responses. A feedforward shaping controller for the strip top part and a feedforward model reference controller for the strip tail part are respectively designed, they are combined with an ILQ(Inverse Linear Quadratic optimal control) feedback controller for the strip middle part. It is shown from by a computer simulation that the proposed controller is very effective to the strip top-tail parts including the middle part.

• 대한기계학회논문집A
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• 제23권7호
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• pp.1196-1204
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• 1999

adaption of the model predictions is highly desirable. In general, the width deviation at the head and tail ends of strip may be different from that of the steady state region. Therefore, the dynamic edger corrections can be used to compensate the width deviations which would otherwise occur. For the precise width control, the effect of edger roll gap and rolling conditions on the width deviation of head and tail ends of strip has been investigated and the effective method to decrease width deviation has been proposed. On-line application of dynamic edger control method in this study shows about 50% width compensation at the head end of the strip, and near perfect compensation at the tail end of strip.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.175.3-175
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• 2001

A control system for crop cutting in Hot strip Mill is developed. The development system is composed of three sub-systems. one is crop shape system which captures the shapes of the strip's head and tail using the area CCD camera. Another is Laser Speed System which measures the speed and length of strip. and, the other is control system which controls the optimal cutting length and crop shear motor. As a result, with a developed system we can reduce crop loss considerably.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.27-36
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• 1999

To have high flatness quality of hot rolled strip in the hot strip finishing mill train, a new inter-stand tension profile measuring device of segmented looper roll type(coined as Flatness Sensing Inter-stand Looper, FlatSIL) and a new flatness control system have been developed in this study. The device measures the strip tension profile across the strip width and informs the strip wave pattern to new flatness control system where work roll bending mode to relieve the strip wave is determined. The existing automatic shape control system which uses laser type shape-meter installed at the outlet of the last finishing mill stand strip tension between down coiler and last finishig mill since the latent wave concealed by the strip tension between down coiler and last finishing mill stand cannot be measured by the laser distance-meter. Thus the existing shape control system is not able to control the flatness through the full strip length. The new flatness control system, however, works for full strip length during strip rolling as far as the tension profile measuring device and work roll bender are on. With the new flatness control system, work roll bender is automatically controller to minimize the latent wave of the running strip and the flatness quality as well as strip travelling stability has been noticeably improved from strip head through body to tail.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.116.3-116
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• 2001

A diagnosis methodology for thickness quality in hot finishing mill is proposed based on multivariate statistical analysis. The thickness of hot strip is a key quality factor that is measured by x-ray thickness gauge. Currently, the thickness quality is guaranteed by upper and lower limit of thickness deviation from target thickness. But if any over-limit is occurred, there is no in-line method to identify the causes. In this paper, many parameters are extracted from the thickness deviation signal such as mean deviation(top, middle, tail), rms deviation(top, middle, tail) and peak deviation(top, middle, tail) as time domain parameters ...

• 제어로봇시스템학회논문지
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• 제21권9호
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• pp.869-874
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• 2015

We developed an LSDC (Load Shift and Load Distribution Control) technology in order to improve coil quality and productivity by reducing tension fluctuation especially for the tail of the strip in the down coiler in hot strip mills. To adapt the new controller, the torque and speed distribution between the zero pinch roll, pinch roll, and mandrel are needed. The proposed controller is a combination of an LSC to share the tension between the mill stand and the mandrel, and an LDC to shift the torque load from the zero pinch roll to the pinch roll. From the simulation, the proposed controller is verified under the torque disturbance. Using a field test, the torque deviation decreased by nearly 50% through utilization of the LSDC control.

• 한국공작기계학회논문집
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• 제10권5호
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• pp.96-103
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• 2001

The quality requirements for thickness accuracy in cold rolling continue to become more stringent, particularly in response to exacting design specification from automotive customers. One of the major impacts from the tighter tolerance level is more unusable product on the head end and tail end of tandem mill coils when the mill is in transition to or from steady state rolling condition. A strip thickness control system for a tandem cold steel rolling mills is composed with blocked non-interacting controller and controllers for strip thickness and tension control of each rolling stands. An intelligent mathematical model included an elastic deformation of strip has been developed and applied to the field in order to predict the rolling force. The simulated results showed that the effect of elastic recovery should be included the model, even if the effect of elastic compression was not important.

• Journal of Nutrition and Health
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• 제25권6호
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• pp.511-517
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• 1992

한국산 야생식용식물의 형당강화 효과를 보기위해서 일차적으로 5가지 식물(냉이, 닭의장풀, 메꽃, 며느리배꼽 및 참마)을 채집하였다. Strcpotozotocin(45mg/kg)을 미정맥으로 주사하여 당뇨병을 유발시킨 130~180g Sprague-Dawley계 흰쥐를 대조군과 실험군으로 나누어 이를 5가지 식물을 adlibitum으로 공급하였다. 식용식물섭취에 따른 각군의 체중변화는 제 3주까지는 점차 증가하다가 냉이군과 메꽃군을 제외하고는 제4주째에 증가추세가 둔화되었다. 식이이용효율은 닭의장풀군이 대조군에 비해 유의적으로 높게 나타났으며(p<0.05) 냉이군, 메꽃군, 참마군과 며느리배꼽군에서는 식이이용효율에 차이가 없었다. 닭의장풀군, 참마군과 며느리배꼽군은 대조군에 비해 혈당 감소 경향이 지속적으로 나타났고, 뇨당의 경우에서도 닭의장풀군과 참마군에서는 검출되지 않았으며 며느리배꼽군에서도 한마리를 제외하고는 뇨당이 검출되지 않아 당뇨유발쥐에서 혈당강하에 효과가 있는것으로 추정된다. 혈장 중의 cholesterol수준은 대조군에 비해 며느리배꼽군에서 약간 높은 경향을 보였으나 유의적인 차이는 없었다. 야생식용물의 건조시료 중 조섬유의 함량은 며느리배꼽이 24.4%로 가장 높았고, 가장 낮은 것은 참마로 2.5%였다. 생시료중 Vitamin C의 함량은 냉이가 193.73mg으로 가장 높았고 닭의장풀, 며느리배꼽, 메꽃슨이었고 참마가 24.6mg으로 가장 낮았다. Fe의 함량도 냉이가 14.86mg으로 높았고 참마가 가장 낮았다. Cr과 Zn의 함량도 냉이에서 높았고 참마에서 낮았다. 앞으로 야생식용산채류에 대한 성인병 예방 및 치료에 대하여 영양학적 연구가 더 많이 이루어져야 할 것이다.