• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.10a
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• pp.13-16
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• 2000

In the hot strip mill, a bad threading and shape of strip strip in the finishing mill was caused by asymmetric rolling In roughing min. Mathematical analysis for camber control of roughing mill in hot strip rolling has been developed. Each equation in the camber control model was derived from geometrical characteristics of camber mechanism. The model can predict variables such as wedge, side slippage and roll force difference etc. from a measured camber value and then find an optimum roll gap condition for minimizing camber in the next pass.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1083-1086
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• 1996

Cold rolling mill process in steel works uses stands of rolls to flatten a strip to a desired thickness. At cold rolling mill process, precalculation determines the mill settings before a strip actually enters the mill and is done by an outdated mathematical model. A corrective neural network model is proposed to improve the accuracy of the roll force prediction. Additional variables to be fed to the network include the chemical composition of the coil, its coiling temperature and the aggregated amount of processed strips of each roll. The network was trained using a standard backpropagation with 4,944 process data collected from no.1 cold rolling mill process from March 1995 through December 1995, then was tested on the unseen 1,586 data from Jan 1996 through April 1996. The combined model reduced the prediction error by 32.8% on average.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.469-473
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• 2001

This paper describes a rotation-type field mill to measure the electric field intensity caused by thunderclouds on the ground level. The field mill developed is consisted of two isolated electrode vanes, a grounded stator and a rotor. To develop a high sensitive field mill, the principles and design rules of a rotation-type field mill are studied. Also, two types of calibration system, such as a cylindrical guard electrodes and a parallel-plate electrodes, are proposed to determine the sensitivity and frequency bandwidth of the field mill. From the calibration experiment, the frequency bandwidth and the sensitivity of the field mill arc DC ∼ 200 [MHz] and 0.267 [mV/Vm], respectively. Therefore, it can measure the electric field intensity from 73[V/m] to 18.7[kV/m].

• Journal of the Korean Institute of Rural Architecture
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• v.16 no.1
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• pp.9-16
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• 2014

It is very hard to find out water mill and water mill house installed nearby a streamlet to use water to polish cereals by pounding like a visage of its old days. It plays an important part in folkloric, hydrographical and architectural aspects as important folklore material in Korea. The purpose of this study is to analyse the folkloric, hydrographical and architectural features of water-mill and water-mill house itself so that to find the way how to build and fabricate the materials and frame members. Therefore this study has been focused on the composition principle and fabrication method of water mill and water millhouse on the side of architecture.

• Agricultural and Biosystems Engineering
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• v.2 no.1
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• pp.7-14
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• 2001

A rice mill plant with a capacity of 3 t/h was constructed with automated facilities at Chonnam National University. A simulation model was developed with SLAMSYSTEM for evaluation and improving the rice mill process. The developed model was validated in the views of hulling efficiency, milling efficiency, milled rice recovery, other materials produced, at bottlenecks in the processes. The results of hulling efficiency, milling efficiency, milled rice recovery in the simulation were, respectively, 81.1%, 89,5%, and 73.1%, while those of the actual mill plant were 81.5%, 90.2%, and 73.5%. The simulation results including the rates of other materials(chaff, bran, broken rice, stone, etc) produced in the processes were almost similar with those of the actual process. In the simulation the bottlenecks were found out in the process for separating brown rice and sorting colored rice. These phenomena also appeared in the actual process. It needed to increase the hourly capacities of the brown rice separator and the rice color sorter. As the developed model could well express the automated rice mill plant, it could be used for designing and improving rice mill plants.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05a
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• pp.650-655
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• 1995

AUC-$UO_2$, ADU-$UO_2$ 분말이 ball mill과 attritor mill에서 분쇄될 때, 기공도변화를 측정함으로서 분말의 특성변화와 분쇄거동을 관찰하였다. 분쇄전 ADU-$UO_2$ 분말은 0.3-7 $\mu\textrm{m}$ 범위의 기공들이 고르게 분포하였으며, ball mill에서 분쇄되어도 그 분포는 거의 변화가 없었다. 분쇄전 AUC-$UO_2$ 분말은 3-8 $\mu\textrm{m}$와 0.05-0.2 $\mu\textrm{m}$ 범위의 기공이 주로 생성되어 있는 bimodal 분포를 나타내었다. Ball mill에서 분쇄됨에 따라 3 $\mu\textrm{m}$이상의 큰 기공과 0.2 $\mu\textrm{m}$ 이하의 작은 기공이 소멸되고, 0.2-3 $\mu\textrm{m}$의 기공들이 고르게 분포하는 경향을 나타내었다. 반면에 AUC-$UO_2$가 attritor mill에서 분쇄될 경우에는 bimodal 분포는 그대로 유지하면서 3-8 $\mu\textrm{m}$의 큰 기공은 줄어들고 0.05-0.2 $\mu\textrm{m}$의 기공은 그 양이 증가하는 경향을 나타내었다. 이것은 ball mill에서는 주로 충격작용에 의해서, attritor mill에서는 전단작용에 의해서 분쇄가 진행됨으로 인한 분쇄기구의 차이인 것으로 사료된다.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.597-608
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• 1998

A diagnosis system that provides early warnings regarding machine malfunction is very important for rolling mill so as to avoid great losses resulting from unexpected shutdown of the production line. But it is very difficult to provide early warnings in rolling mill. Because dynamics of rolling mill is non-linear. This paper proposes a new method for diagnosis of rolling mill using wavelet to solve this problem. Proposed method that measures the vibration signals of rolling mill on-line and analyze it using wavelet to acquire pattern datas. And we design a nero-fuzzy model that diagnose a rolling mill using this data. Validity of the new method is asserted by numerical simulation.

• Journal of the Korean Ceramic Society
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• v.24 no.1
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• pp.47-55
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• 1987

The purpose of this work is to establish the basic calibration data for the efficiency of grinding by investigating the Bond's Work Index employing Korean Kaolin as a reference mateial with the laboratory-scale ball mill. A small ordinary ball mill has a dimension of 133 inside diameter and 144mm long. The analysis of the experimental results in this work sets up a equivalent calibration method with the laboratory-scale ball mill to those with special mill. The theoretical expression, derived from the rate equation proposed by Miwa, is obtained to anticipitate the stable revolution number for the next grinding cycle. The proposed equation is more systematic and acurate than lshihara's empirical equation is more systematic and acurate than lshihara's empirical equation for the measurement of gindability of a ball mill.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.08a
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• pp.452-456
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• 1999

Newly constructed plate shape control system, using attached shape measuring instruments and work roll bender, was put in service in No. 2 Plate Mill, POSCO. Recently, customers demand the improvement of flatness and plate crown accuracy. Many competition Plate Mill introducted shape control system, for example, pair cross mill, work roll bender which includes shape measuring instrument and shape control mathematical models, and No. 2 Plate Mill, POSCO introducted work roll bender and shape measuring instruments. This report describes the properties of No. 2 Plate Mill shape control system and work roll bender.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.131-135
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• 1999

The objective of this research was to improve moisture retention capacity of pine bark. To achieve this, barks were ground with Wiley mill of hammer mill and were blended with recycled rockwool. Then, changes of soil physical properties were determined. The percentage of particles larger than 5.6 mm was 86.5% in raw materials. The percentage of particles larger than 1 mm decreased and those of particles smaller than 1 mm increased by grinding with Wiley mill or hammer mill. Grinding with Wiley mill showed better effect than those of hammer mill in decreasing particle size distribution. Grinding resulted in decreased total porosity (TP) and air space (AS) and increased container capacity (CC) and residual water content (RW), indication improved moisture retention capacity. The material ground with Wiley mill, than blended with 50% recycled rockwool had 81.1%, 67.7%, 13.5% and 235 ml in TP, CC, AS and RW, respectively. These results indicated that moisture retention capacity was improved by blending with recycled rockwood, but aeration of root media was much better than those of peat+vermiculite(1:1, v/v), which is commonly used in commercial production.