• KEPCO Journal on Electric Power and Energy
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• v.8 no.2
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• pp.49-53
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• 2022

The distribution live-line work method is an operation method of working in a state in which electricity flows through overhead distribution lines to minimize inconvenience to electric customers due to power failure. In June 2016, to strengthen the safety of electrical workers, Korea Electric Power Corporation announced that it would in principle abolish the rubber glove method, in which workers wore protective equipment such as rubber gloves and performed their maintenance work. In addition, KEPCO announced that it would develop a short-range live working method using smart sticks and an advanced live-line maintenance robot system where workers work without touching wires directly. This paper is a preliminary study for the development of the live-line maintenance robot system, and deals with the results of analyzing the technical feasibility of whether the live works performed by workers can be replaced by robots or not.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.5
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• pp.118-126
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• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.

• Proceedings of the KIEE Conference
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• summer
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• pp.619-621
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• 2004

This paper presents the rapid and accurate algorithm for fault discrimination in transmission lines. When faults occur in transmission lines, fault discrimination is very important. If high impedance faults occur in transmission lines, it cannot be detected by overcurrent relays. The method using current and voltage cannot discriminate high impedance fault. Because of this reason this paper uses voltage and zero sequence current, and the proposed algorithm uses fuzzy logic method. This algorithm uses voltage and zero sequence current per period in case of faults. Single line ground fault and three-phase fault can be detective using voltage. Two-line ground fault and line to line fault and high impedance can be detected using zero sequence current. To prove the performance of the algorithm, it test algorithm with signal obtained from ATPDraw simulation.

• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.200-202
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• 2008

The oscillation is very dangerous in bundled transmission lines, especially 345kV 4 bundle transmission lines are very weak for subspan oscillations. In some cases, subspan oscillations are continuously occurred in the same subspan. In order to develop the control method of the above subspan oscillation, this paper suggests a method of applying twin spacers to the subspans. We have carried out some tests to analyze the oscillation phenomena after installing twin spacers on 34sky real lines, and we got a good effect for controling subspan oscillations.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.3
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• pp.417-429
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• 1998

This paper considers two-sided (left and right side) assembly lines which are often used, especially in assembling large-sized products such as trucks and buses. A large number of exact algorithms and heuristics have been proposed to balance one-sided lines. However, little attention has been paid to balancing two-sided assembly lines. We present an efficient algorithm based on a branch and bound for balancing two-sided assembly lines. The algorithm involves a procedure for generating an enumeration tree. To efficiently search for the near optimal solutions to the problem, assignment rules are used in the method. New and existing bound strategies and dominance rules are else employed. The proposed algorithm can find a near optimal solution by enumerating feasible solutions partially. Extensive computational experiments are carried out to make the performance comparison between the proposed algorithm and existing ones. The computational results show that our algorithm is promising and robust in solution quality.

• Journal of Life Science
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• v.14 no.1
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• pp.57-60
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• 2004

To get basic information on the Korea local corn lines collected from Busan and Gyungnam Province, a total of 49 lines were classified by the principal component analysis method. The lines were classified into 4 lineal groups by the taxonomic distance. Croup I included 11 lines, and groupII, groupIII and groupIV included 20 lines, 14 lines and 4 lines, respectively. Four groups could be characterized as follows: Croup I : early maturity, short plant, small ears, small kernels, low tillering and medium yielding. Croup II : early maturity, tall plant, large ears, large kernels, multi-ears, low tillering and high yielding. GroupIII: late maturity, short plant, small ears, small kernels, high tillering and low yielding. Croup W medium maturity, tall plant, large ears, small kernels, prolific ears, high tillering and higher yielding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.128-133
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• 1998

Analyses of now karyotypes using different maize (Zea mays L.) inbred lines have been performed. The accumulation and isolation of high quality and quantity metaphase chromosomes from root tips can be achieved from many kinds of maize lines. The chromosome suspensions were prepared by a simple slicing method from synchronized maize root tips and analyzed with a now cytometry. The variations of experimental now karyotypes were detected among inbred lines in terms of the positions and/or the numbers of chromosome peaks. The 2C DNA amount among 8 inbred lines ranged from 5.09 to 5.52 pg. The variability of DNA content in maize chromosome 1 was 9.1 % ranging from 0.685 to 0.747 pg. The selection of appropriate maize lines is critical for sorting specific single chromosome types. At least five different chromosome types can be discriminated and sorted from five maize lines.

• Journal of Fashion Business
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• v.20 no.4
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• pp.153-171
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• 2016

With the advent of smart clothing for health care and sports, the sophisticated designs with curved seams are drawing attention. One of the problems in those clothing is to determine the design curves in 2D pattern, such that it corresponds to the lines on the intended 3D body. Moreover, the difficulty increases when the original pattern needs to be changed for various sizes and body types. We compare two methods of pattern enlargement in this paper: one is the offset/projection type, and the other is the split grading type. For the enlarged pattern with offset/projection type, the 3D surface offset was first adopted to transform the standard lower body to the target larger size; next, the design lines were projected to the new 3D surface, following which the 3D pattern was developed from the newly transformed 3D surface. In the second method, the enlarged pant patterns were developed by the split grading method. Here, a 3D pattern was developed from the initial body, and then enlarged to the target size by the conventional split grading method. Two feminine pants patterns were examined by 3D virtual fitting. We observed that the 3D offset/projection pants pattern was well fitted, having an evenly distributed surplus, as compared with the sample developed using the split grading method. The difference between the two patterns were apparent at the location where several curved lines merged.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1791-1793
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• 1997

Since Korea was initiated a industrialization, many transmission lines have been installed to meet the increasing demand for the electric power. In large city, underground transmission lines were widely installed because of the environmental issue. But there have been appeared many failures on the lines, such as the external scar of cable, a fire in the culvert, overheating of cable, and so on. There have been many studies to monitor them and improve the reliability of the power supply. As a method monitoring the lines, a DTS(Distributed Temperature Sensor) system is developed and applied. This system monitors the lines and predicts the failures, using a optical fiber sensor. This paper describes this DTS system and its application for the underground transmission lines.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.2 s.245
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• pp.141-148
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• 2006

In this paper, a new offset algorithm for closed 2D lines with islands is introduced and the result is illustrated. The main point of the proposed algorithm is that every point is set to be an offset by using bisectors, and then invalid offset lines, which are not to be participated in offsets, are detected in advance and handled with an invalid offset edge handling algorithm. As a result, raw offset lines without local invalid loops are generated. The proposed offset method is proved to be robust and simple, moreover, has a near O(n) time complexity, where n denotes the number of input lines. In addition, the proposed algorithm has been implemented and tested with 2D lines of various shapes.