• Journal of Electrical Engineering and Technology
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• v.8 no.6
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• pp.1503-1511
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• 2013

This paper deals with the analysis of leakage current characteristics of silicone rubber insulator in order to develop a new condition monitoring tool to identify the flashover of outdoor insulators. In this work, laboratory based pollution performance tests are carried out on silicone rubber insulator under ac voltage at different pollution levels and relative humidity conditions with sodium chloride (NaCl) as a contaminant. Min-Norm spectral analysis is adopted to calculate the higher order harmonics and Signal Noise Ratio (SNR). Choi-Williams Distribution (CWD) function is employed to understand the time frequency characteristics of the leakage current signal. Reported results on silicone rubber insulators show that the flashover development process of outdoor polymer insulators could be identified from the higher order harmonics and signal noise ratio values of leakage current signals.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.2
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• pp.151-158
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• 1995

A study was carried out to investigate the effect of palm oil supplementation on the growth, carcass composition and fatty acid distributions of the broilers fed isonitrogenous and isocaloric diets. This study showed that palm oil supplementation increased feed consumption, weight gain and nitrogen intake. Feed conversion improved at higher fat inclusions, but not significant. Male birds consumed significantly more feed than females resulting in significant increase in energy consumption and weight gain. Increaseing fat content in the ME:P constant diet did not produce significant difference in the fat content of the chicken. Fatty acids content of the diet exert varying effects of the composition and distribution of fatty acids in muscles of the chicken. The fatty acids found in larger amount in the breast and thigh muscles were palmitic, oleic and linoleic. The fatty acids of the breast and thigh muscles were found to correspond the fatty acids of the diets. There were no differences in the fatty acids distribution patterns between the sexes.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.3
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• pp.128-134
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• 2006

The most of national industrial complex were developed and supplied not according to the requirements of enterprise but the needs of the government. And it leads to current serious out of balance in demand and supply of industrial complex. Buckpyoung industrial complex started sale from when the industrial complex developed in 1995 however the unsold percentage of it was 67% until in October,2005. And this result was ranked the top in the unsold percentage among the 42 national industrial complex in korea. In this paper we research how to accelerate the sale of Buckpyoung industrial complex and to reinvigorate local economy and present the constitution of building material cluster and physical distribution system as the results of our research.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.30 no.3
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• pp.135-141
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• 1994

In order to investigate remotely the behavior and distribution of fishes, the telesounder system which was composed of two parts with a buoy station at sea and a base station on land was manufactured trial. The buoy station at sea consists of fishfinder, transmission interface and transceiver. On the other hand, the base station on land consist of transceiver, receiving interface, trigger/signal separator and color display monitor. The system simulation for the performance of telesounder was carried out by use of echo simulator which could input echo signal into fishfinder. The received power (dBm) of transceiver at 29.4MHz decreased almost in proportion to distance between transmitter and receiver, and the electric field intensity was 12.12mV/m at 100 meters distance from transmitter. The image of color display monitor at the base station on land was very well coincident with the records of fishfinder from the buoy station located at sea. Therefore, it is concluded that the telesounder system is very useful in the analysis of the information on the behavior and the distribution of fishes detected from sea.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.11
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• pp.558-565
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• 2000

In this paper, we propose a method for mitigating for mitigating the effect of voltage of voltage sag in radial power distribution systems using load transfer switching (LTS). The term of LTS is defined that the weakness load points for voltage sag transfer to the alternative source during the fault clearing practices. The sequenced of proposed LTS method is divided into the search of weakness points for voltage sag using the risk assessment model and transfer behavior of weakness points. The search of weakness point is carried out using the risk assessment model of voltage sag and Monte Carlo simulation method and the historical reliability data in Korea Electric Power Corporation (KEPCO) are also used. Through the case studies, we verify the effectiveness of proposed LTS method and present the searching method of effective application points of LTS method using the risk assessment model.

• International Journal of Automotive Technology
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• v.7 no.4
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• pp.493-500
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• 2006

Investigation on the fuel adhering on a wall was carried out experimentally to clarify the characteristics of impinging diesel sprays. Diesel sprays were injected into a high-pressure chamber of cold state and impinged to a wall having various impingement distances and ambient pressures. Photographs of both the fuel film and the post-impingement spray were taken through a transparent wall. Adhered fuel mass on a wall was measured by means of dividing into two types of fuel state: the fuel film itself; and sparsely adhered fuel droplets. Adhering fuel ratio was predicted and further the distribution of fuel mass for impinging diesel spray was analyzed as a function of time. As result, with an increase of the ambient pressure, both the maximum fuel film diameter and the adhered fuel ratio decreased. Based on some assumptions, the adhering fuel mass increased rapidly until the fuel film diameter approached the maximum value, and then increased comparatively gradually.

• Transactions of Materials Processing
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• v.7 no.5
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• pp.489-495
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• 1998

Spinning is a chipless forming method for producing axially symmetric parts by using axial-radial motions of a spinning roller. This process has still some advantages in such a view point that a variety of complex shapes which can not be formed in a press can be easily spun at a low cost although it is one of the oldest forming methods for spinning mainly cookware parts for a long time. This study is to investigate the optimum roller path in order to obtain the maximum spinnability in producing cylindrical cups of Aluminum(A1050-H16) sheet metal. Working conditions applicable to any size of blank were predetermined through preliminary spinning tests. 9 types of roller path were proposed and experiments were carried out. The modified involute curve was shown to give the maximum drawing ration and more uniform quality of spun cups as compared with other results of this study. in addition thickness distribution and dimensional accuracy of spun cups were examined and discussed.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.13-18
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• 2004

It is important to estimate the distribution of intensity of a magnetic field for application of magnetic method to industrial nondestructive evaluation. Magnetic camera provides the distribution of a quantitative magnetic field with homogeneous lift-off and same spatial resolution. Leakage magnetic flux near the crack on the specimen could be amplified by 3-dimensional magnetic fluid and zoom in and out of measurement area. This study introduces the experimental consideration of the effects of lens for concentrating of magnetic flux. The experimental results showed that the magnetic fluid has sufficient lens effect for magnetic camera and effect of improvement in probability of detection.

• Journal of Fisheries and Marine Sciences Education
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• v.19 no.3
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• pp.383-389
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• 2007

To evaluate the performance of heat exchanger with rotating porous plates, the experimental investigation was carried out under various conditions. With an equal interval of 18 mm inside the heat exchanger, the rotating porous plates are mounted. The hot and cold airs enter at opposite ends of heat exchanger and exchange heat each other. In order to measure the temperature distribution of the hot air side inside heat exchanger, the thermocouples are inserted between the plates. The first location of thermocouple is 10 mm downstream from the inlet of heat exchanger, and succeeding ten locations are aligned at an equal interval of 18 mm. As a result of the measurement, the temperature distribution inside heat exchanger was constant as the hot air temperature of inlet is low. It was found that the heat transfer rate does not depend on the variation of RPM at the lower temperature of inlet. The heat transfer rate at the higher temperature of inlet increased a little with the increase in RPM.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.11
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• pp.479-486
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• 1986

It is necessary to consider a rotor movement in dynamic analysis on the flux distribution of electric machinery by FEM. Therefore, if air-gap domain was subdivided into triangular elements, computation results contain errors due to variation of element shape in air-gap because the nodal points corresponding to the rotor are displaced in analyzing domain for the time difference. In order to reduce this errors, the paper presents a application of a Macro Air-gap Element that interpolation function is obtained analytically and a means to join it with linear triangular elements in the rotating machine or in the linear machine. At the end of paper, setting up analytic domain model, it compares analytic solution with the computation results of Macro Air-gap Element appliction and that of linear triangular element subdivision only to each cases of nodal displacement. And it carries out that errors due to variation of element shape are reduced effectively by application of a Macro air-gap element.