• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.74-79
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• 2004

The shape of cold rolled steel sheets is the degree of flatness, and the flatter, the better. Because undesirable strip shapes of cold rolled steel sheets can affect not only visible problem but also automatic working process in customer's lines, the requirement of the customers is more and more stringent. So we usually used the tension leveler to make high quality of strip flatness. For the improvement of the quality of strip flatness, this report developed three-dimensional FEM (Finite Element Method) simulation model, and analysis about the strain and stress distribution of strip in the tension leveling process.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2203-2206
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• 2005

A load flow and short circuit fault simulation of AC electrified railway distribution systems is presented with DIgSILENT PowerFactory software. Load flow of electrified railways distribution system with concerning multi train lines and dynamic characteristics of train load is studied for different time laps. The dynamic characteristics of train load in starting and braking conditions with different starting and stopping times and its moving positions makes the load flow complicated so there is a great need in studying the effects of electrified railways on load flow. Short circuit fault transients is also studied and simulated for both power system or traction distribution system and their effects on the operation of the train sets is investigated.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.10
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• pp.1349-1355
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• 1999

A power distribution facility map is drawn on cadastral map. Besides, grid lines are added on the map for sectionalization. For automatic recognition of the map, we first extract recognizing regions. In this paper, we propose an extraction method of recognizing regions by partially extending thinned image. The proposed method is consist of three phases, binarization phase, thinning phase and partial extending phase. The first phase generate a binary image using threshold value which is obtained by histogram analysis. The binary image contains many part of recognizing regions, but not all. The second phase generate thinned image which is generated by appling thinning operator to the binary image. And the third phase extends thinned image from terminal point until satisfying termination condition. The proposed method is tested on several power distribution facility maps, and the results are presented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.8
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• pp.539-543
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• 2015

At present, the development of a detection device in order to prevent accidents due to wire deterioration in the distribution lines is required. Distribution line is not possible to check the internal state in a normal way because it is covered with the coating. Accordingly, various eddy current techniques that is the non-destructive test (NDT) techniques have been applied to solve this problem. In this paper, we have seen examining the characteristic change of the eddy current sensor according to the simplified shape of the sensor in order to solve the problems for the simplified shape that is generated when the simulation for the shape of the eddy current sensor.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.558-560
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• 1997

In recent years, it becomes a worldwide trend that the power utilities focus their attention to the automation of their power plants and distribution systems, employing recent developed communication technologies. Following this trend, KEPCO has installed optical communication links along its power distribution lines and at the same time, has exhausted much efforts to implement its own Distribution Automation Systems(DAS) in possible early date. This paper presents some of initial design efforts toward KEPCO's DAS at KEPRI.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1469-1470
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• 2015

Recently induction generator has been applied to many small hydro power plants. Induction generator needs a reactive power for magnetization. The reactive power of induction generator is being supplied from the supply side mostly. The use of induction generators in the power distribution grid can affect the power factor. The power factor of induction generator is fixed already during production. The power factor in the distribution system is due to the increase or decrease of the load rather than due to the induction generator. In this study, we analyzed how the power factor is changed according to the load increase or decrease in the distribution lines.

• Ocean and Polar Research
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• v.25 no.4
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• pp.633-644
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• 2003

The distribution and abundance of Antarctic krill (Euphausia superba), particularly in the South Atlantic, has traditionally been viewed as primarily determined by the flow of the Antarctic Circumpolar Current. Krill are viewed as being particles on a conveyor belt that carries them around the Antarctic continent resulting in a single circumpolar population. The evidence to support this viewpoint is largely circumstantial and there is very little direct evidence available of krill being moved by the currents-krill flux. There is also considerable biological and physical evidence which suggests that other factors may play a dominant role in the life history and distribution of krill. This review examines the evidence fur krill flux and also examines evidence that does not accord with this theory. The management implications of assuming krill flux are outlined and some lines for future research are suggested.

• Journal of the Korean Ceramic Society
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• v.23 no.4
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• pp.35-40
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• 1986

The production process of a fine size fraction of Korean kaolin by ball milling is studied in this paper by analyzing the size distribution the size distribution of products with the Rosin-rammle formular and the rate process of cumulative size fractions with Alyavdin-Chujyo's formular. The size distribution is found to be divided in three regions a coarser part influenced by feed size an intermediate part where the size distribution shows a clear straight line relationship on Rosin-Rammler chart and the finest part with the ultimate limit of fineness by ball milling. Alyavdin-Chujyo's relationship is found to be valid over a very wide range of milling conditions. For different feed sizes the Alyavdin-Chujyo's relationship gives a group of straight lines with a common intersection point which can be defined as the limiting point of the persistent component region.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3094-3096
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• 2000

In the distribution systems, there are generally two sources of transient over-voltages. One is the capacitor switching surge and the other is the lightning surge. This paper is written about the measuring and analysis of switching over-voltages in the 22.9 kV multi-grounded distribution systems. The measurement was performed in the Kochang distribution test line in January, 2000.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.338-341
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• 2003

This paper proposes the adaptive relaying algorithm of protective devices applied in the neighboring distribution feeders for reliable and efficient operations of a wind farm interconnected with distribution networks by dedicated lines. Generally, it would be highly possible that the wind turbine generators are influenced by abnormal grid conditions such as disturbances occurring in the neighboring distribution feeders as well as the dedicated power line. The delayed operation time of protective devices for satisfying the coordination might overly expose the interconnected wind turbine generators to the fault and cause damage to them. In order to reduce the damages on the interconnected wind farm about the faults happening in distribution networks, this paper describes the proper delayed operation time of protective relay.