• Progress in Superconductivity and Cryogenics
• /
• v.15 no.3
• /
• pp.20-23
• /
• 2013

In the development of high temperature superconducting (HTS) power machines, HTS bushing is one of core technologies. In particular, the insulation body with sheds and electrical insulation at cryogenic temperature have attracted a great deal of interest from the view point of the size, weight and efficiency of bushing. In this study, the electrical and mechanical characteristics of various insulators for body in liquid nitrogen ($LN_2$) were investigated. And the surface discharge distance, collar length of GFRP sheds were studied. To emit bubbles between sheds, the shape and arrangement of shed were studied. The shed structure for 60 kV class HTS bushing were designed with regular arrangement.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1994.10a
• /
• pp.515-518
• /
• 1994

Holographic interferometry is a useful whole-field nondestructive testing for measuring deformations and vibrations of engineering structure. A diverging beam is used as a light source int the most of holographic interferometer practically. For a relatively small object the optical arrangement using a collimated light source has no difficulty in use technically, but for a large object it is difficult to use a collimated beam. In this study we calculate the error of measured displacement from the sensitivity vector dominated by the geometry of optical arrangement for holographic interferometer and show the result obtained with 2-D plots. A Plane surface and a cylindrical surface were chosen as objects to be calculated and computer analysis was carried out for the cases of a diverging beam and a collimated one.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.2 no.1
• /
• pp.74-83
• /
• 1990

The temperature distributions inside molds with heating or cooling tubes were calculated using special boundary element method. This special boundary element method was employed in order to reduce the error for small diameter tubes. Calculated temperature was compared with results using finite element method. It was found that the current method becomes more accurate as tubes' diameter gets smaller. Optimal arrangement of tubes for uniform temperature distribution along specific surface was found. CONMIN program was employed for the optimization.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2001.05a
• /
• pp.129-134
• /
• 2001

The drag reduction of the cylinder having square dimpled surface was studied by the measuring the drag force acting on the cylinder. The level of the drag reduction was changed by the arrangement shape of the square grooves and Reynolds number. The drag of the cylinder was reduced about 28% with proper arrangement of square grooves. The flow field around the cylinder having grooves at the minimum drag was visualized by using post color ink in order to see the influence of the grooves. In this case, the separation points were sifted rearward and the wake region was smaller than that of the smooth cylinder.

• Journal of Advanced Marine Engineering and Technology
• /
• v.26 no.2
• /
• pp.233-239
• /
• 2002

The drag reduction of the cylinder having square dimpled surface was studied by the measuring the drag force acting on the cylinder. The level of the drag reduction was changed by the arrangement shape of the square grooves and Reynolds number. The drag of the cylinder was reduced about 28% with proper arrangement of square grooves. The flow field around the cylinder having grooves at the minimum drag was visualized by using post color ink in order to see the influence of the grooves. In this case, the separation points were silted rearward and the wake region was smaller than that of the smooth cylinder.

• Special Issue of the Society of Naval Architects of Korea
• /
• 2011.09a
• /
• pp.90-94
• /
• 2011

Longitudinal shell member that arranged block unit on 3D-curved surface is performed manual working by designer considering spacing of division characteristic, location and twisting at geometrical 3-dimensional form. Shell expansion drawing that drawn by initial design and shell landing work performed by hull production design have overlap of design work in terms of arrangement of shell longitudinal member. In this study, eliminate design overlap on shell member arrangement that is one of ship longitudinal member. Develop shell member optimization and auto arrangement system.

• Fashion & Textile Research Journal
• /
• v.8 no.4
• /
• pp.400-406
• /
• 2006

The purpose of this study is to investigate characteristics of arrangement methods and weaving types of fabrics during 16-17 century. Research was done through the references of exhumed clothing in Chosun Dynesty. Seeing the waving types of fabrics of flower patterned fabrics of total 108 items, satin damask(Dahn) was 71items, took the majority. And the next order was twill(Neung) and plain(Ju). It means Dahn was the most popular fabric among the upper classes. It was regarded as one of the noble textiles, because of its luxurious appearance and pleasant touch. Flower patterned plain fabric(Munju) was found only 9items, even though the plain fabric was the most common used type. Assumed for the reason, Chosun government had restrict to extravagance of the people. In terms of the arrangement of flower pattern, it can be classified into three methods. The most common arrangement method was Arabesque type, followed by open order shaped type and scattering shaped type. In the repetition of pattern, there were brick-shaped pattern and half drop pattern which were spread flower pattern all over the surface of fabric.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.2
• /
• pp.87-94
• /
• 2007

It has been argued that the use of plastics can cause problems during design and manufacture owing to their low strength, relatively poor thermal conductivity and large thermal expansion. However, the advantages of plastics e.g., corrosion resistance, low cost, curtailment of weight, design flexibility etc., can compensate abundantly for the disadvantages. This study analyzes and compares the heat transfer performance characteristics of automotive compact oil cooler composed of plastic tube bundle with conventional metal oil cooler on the same core area basis as diameter, tube thickness, number of tube or tube arrangement varies. The performance analyses are accomplished by use of computational fluid dynamics program Fluent 6.2, which is verified and compared with the results of performance tests. The result of analyses is coincided with that of experiments. Flow pattern at air side according to tube arrangement is dominant factor which affects heat dissipation in case of similar total heat transfer surface area.

• Journal of Korea Water Resources Association
• /
• v.43 no.9
• /
• pp.781-787
• /
• 2010

A new method for water level measurement method and its verification results are described. In this method, water surface in motion can be detected by temporal variation of pixel arrangement in successive digital images including the boundary between the staff gauge and the water surface. Laboratory and field tests were conducted for the two cases in which the staff gauge was contaminated by dirt or transparent due to clear water. The result shows water level can be accurately measure by this method for these two cases. It is expected that the accuracy of previous image stage gauge will be improved by the new method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.7
• /
• pp.685-692
• /
• 2016

A cutting head is an attachment on the front of an excavator that cuts or grinds rocks. Cutting tools, called pick cutters, are arranged on the surface of the cutting head. The exact arrangement and configuration of pick cutters is one of the most important factors in determining grinding efficiency. This study focuses on the problem of automation for pick arrangement design, in order to make the design process more efficient and convenient. Design automation was carried out using RecurDyn/ProcessNet, and it was composed of three parts: 'Drum set', 'Pick load', and 'Pick arrangement' sections. The presented method helps to decrease costs attributed to designing cutting heads and can be used to generate a wide range of attachment mechanisms.