• Journal of Institute of Control, Robotics and Systems
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• v.15 no.3
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• pp.330-336
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• 2009

This paper studies on the new control algorithm for the mass-flow stabilization in strip head part of a hot strip mill. A new strip tension model in the strip head part is derived using the current deviation of two neighboring stands. The current deviation means a difference between a measured current and a lock-on current, where the lock-on current is set up when a strip tension or a looper angle reaches each target value or time is about 0.4sec, respectively. On the basis of the tension calculation model, a mill velocity of a backward stand is controlled to stabilize a strip mass-flow by PI control algorithm. Therefore, the mass-flow control for strip head part is executed from a metal-in time into a foreward stand till the looper works normally. It is known by the results of a computer simulation and an experiment that the proposed control algorithm is very effective in stabilizing the mass flow of the strip head part.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.155-156
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• 2007

This paper presents the vision-based camber and optimal cutting line detection algorithm for hot-rolling process. It is important to measure the camber of head and tail part of strips because many problems are caused by the camber in the hot-rolling process. The hot-rolling process has time constraints. The camber detection algorithm of head and tail parts requires fast and less complex for satisfying time constraints. The proposed algorithm consists of two parts: measurement of the camber in the head and tail part of strips and decision part of the optimal cutting line of hot-rolled strip. First, we obtain the camber value of the strip from the difference between the real center line and the center line of head, tail part. Second, the head and tail part of strips isn't suitable for strips connections. Therefore, the cutting process is needed in the hot-rolling process. The optimal cutting line is determined by the head and tail images obtained from cameras. The algorithm is applied into the vision system with two area cameras, Matrox image processing board and host PC for verification.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.212-212
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• 2000

This study was performed to construct a hot strip speed measuring system and check over whether the measured speed can be used for improving the mass flow of the head-end part of a hot strip in the 7-stand finishing mill. Because the mass flow in hot rolling mill affects the looper operation and the thickness and width control of a strip, accurate measurement of strip speed ie important. The measured speed was compared with the roll speeds of No. 6 and No.7 stand to check the performance of the system and analyzed to find how to apply the speed. As a result, it is shown that the accuracy of the system is enough, strip thickness error can be reduced by -275∼+200$\mu\textrm{m}$ using the measured speed and the existing FSU model has low accuracy for predicting forward slip rate. A neural network was developed to calculate forward slip rate instead of FSU model. The test result of the neural network shows that the neural network is more accurate than the FSU model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.47-56
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• 2013

Rolling speed, roll gap, and cooling pattern in hot strip finishing mill process should be determined before inserting strip into roll. Such parameters are initially calculated by a mathematical set-up model. The technique to find adequate roll speed via a mathematical model has inherently limit because required working conditions are various and rolling process is nonlinear. To improve the accuracy of initial rolling speed for a finishing mill, this paper suggests a correction technology for initial rolling speed. The proposed method was implemented in hot strip mill process. As the results, the magnitude of width error in strip head-end part caused by excessive strip tension was decreased remarkably.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.53.4-53
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• 2001

This paper described about the system which can be inspect work roll surface for deciding a milling schedule and roll changing at hot strip mill in POSCO. Developed system consists of CCD camera, Xenon lamp with fiber bundle and mechanical control part. The water probe build up water pole between head of probe and roll surface to acquisite a good image from a work roll surface under the bad environment with steam, cooling water and high temperature. This system is possible to monitor a work roll surface of about 12${\times}$9mm. We have shown the validation of the developed system which can monitor the evolution of degradation on work roll surface.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.4
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• pp.11-17
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• 2020

This paper proposed the design of a new window signage system architecture, which utilized a window of a building, with attached LED for visible light communication. In this paper, the proposed method using the LED strip to transmit light data and receive the data through a HMD with a smart device camera. The LED strip attached to the existing building window, as a part of semi-transparent signage. Semi-transparent signage based on a controllable LED strip-modules and attached to the window used to provide entertainment contents and the information service to people through optical camera communication (OCC) as well. Also, this work suggests using the camera supplied Head Mounted Device (HMD) as an OCC receiver. The LED attached window signage system structure described in this paper can be utilized in various buildings infrastructure like house, shopping areas, industrial building, etc.

• Journal of the Korean Society of Costume
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• v.4
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• pp.39-59
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• 1981

This article briefly researched the Picture of Welcoming the Governor of Pyongan Province painted by Kim Hong-do, penname Danwon(1745-1818?). The Picture was composed of three parts and its historical and pictorial back-ground were reviewed firstly. And later the dress and its ornament appearing on the Picture were studied. In the historical viewpoint of dress and its ornament, the Picture shown all sorts of dress from lower class maids and servants to higher officials-dignatories and governor, and dealt with nearly all dresses. In order to support and to make better understand the dresses of that age, some Korean literary works of the same period depicting the dress and its ornament were also selected. This article dealt with the dress and its ornament. especially that of 18th century of the Yi Dynasty, and comparatively studied for our folk painting with literary works. Also the picture enabled to make this study was an important data of our old dress and its ornament. This painting was considered as one of our cultural treasures. Several conclusions drawn out from this study as followings: 1) In male and female dress of lower class people; male dress was consist of trouser and coat, and coat, and over the coat SOCHANGYI were used. Female dress was basically consist of skirt and these were white color of their favourite. Mainly simple color was used for clothing and its dress style were CHAKSOO-HYONG (narrow sleeve style) which convenient for a work. 2) Yangban's dress was consist of trouser, coat and over the coat, usually DOPO(over-coat) were used and some case JICKRYONGPO (a sort of over-coat) or CHANGYI were also used. These were GWANGSOO-HYONG (wide sleeve style) of inconvenient for a work. 3) In head-gear, there was no difference of the higher and the lower. They usually used HEUC-KRIP (black Korean hat). The OCKJUNGJA, GONJAKMI (peacock tail), HOSOO (tiger beard), and YOUNGJA (chin strip) were used according to officials ranks as head-gear's oraments. 4) Local petty officials used ordinary dress and CHUPRI (warn-dress) were also used by them, and military officials used war-dress of tight sleeve. 5) The belting of over-coat are different in color according to official grade. The higher grade wore red-wide belt, but generally black narrow belt for ordinary officials. 6) All KISAING girl wore SAMHYEOIJANG upper coat. And their head ornament were black KARIMA for grown KISAING. SAYANG hair for DONGKI or maiden KISAING and BINYEO (an ornamental rod of women's hair) were inserted into the hair of rear down part of head. The water carring maid wore BANHYEOIJANG upper coat and no KARIMA were on head and their coat were gloomy color. Above mentioned are several conclusions, and there migh be a false or erroneous explanations of 18th century dress and its ornament, however I considered they were data for blank period of quite unknown.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.43-46
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• 2010

As the nuclear power plant has been constructed continuously for several decades in Korea, the welding technology for components manufacturing and installation has been improved largely. Standardization for weld test and qualification was also established systematically according to the concerned code. The welding for the main components requires the high reliability to keep the constant quality level, which means the repeatability of weld quality. Therefore the weld process qualified by thorough test and evaluation is able to be applied for manufacturing. Narrow gap SAW and GTAW process are usually applied for girth seam welding of pressure vessel like Reactor vessel, steam generator, and etc. For the surface cladding with stainless steel and Inconel material, strip welding process is mainly used. Inside cladding of nozzles is additionally applied with Hot wire GTAW and semi-auto welding process. Especially the weld joint having elliptical weld line on curved surface needs a specialized weld system which is automatically rotating with adjusting position of the head torch. The small sized pipe, tube, and internal parts of reactor vessel requests precise weld processes like an automatic GTAW and electron beam welding. Welding of dissimilar materials including Inconel690 material has high possibility of weld defects like a lack of fusion, various types of crack. To avoid these kinds of problem, optimum weld parameters and sequence should be set up through the many tests. As the life extension of nuclear power plant is general trend, weld technologies having higher reliability is required gradually. More development of specialized welding systems, weld part analysis and evaluation, and life prediction for main components should be taken into a consideration extensively.