• Proceedings of the KSR Conference
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• 2010.06a
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• pp.692-697
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• 2010

In this paper, a design program for electric railway pole foundation was developed by applying the estimation study performed by Korean Railway. There are two kinds of shapes in the cross-section of electric railway pole foundation: rectangle and circle. In foundation designing, The rectangular foundation should be satisfied with vertical, horizontal and moment equilibrium equations. On the other hand, the circular foundation should be satisfied with horizontal and moment equilibrium equations. The design program was coded into MFC(Microsoft Foundation Class) by MS Visual C. The equation's roots in the program were obtained by Incremental Search method. Dialog and property sheet(Wizard Mode) input windows were selected for user-friendliness. The biggest advantage of this program is to find an optimum depth in a given section.

• Journal of the Optical Society of Korea
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• v.17 no.5
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• pp.371-375
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• 2013

To improve the utilization efficiency of solar energy, a new solar optical concentrating system composed of a parabolic reflector with a square cross-section, a hyperbolic reflector with a square cross-section and two converging convex lenses has been designed. The proposed method can simultaneously focus and shape sun light into a square pattern on the solar panel. In addition, the total reflection property of photonic crystal within the range of the visible sunlight spectrum has been analyzed. Finally, the relationship between solar concentrating multiples and the diameter of the primary mirror has been discussed.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.190-194
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• 2016

자연에서 안정적이고 경제성이 높은 구조로 벌집 구조가 많이 언급이 된다. 이러한 벌집 구조의 특징으로 인해 많은 공학자들이 그 구조를 모방하여 적용하고 있다. 벌집 구조에도 다양한 종류가 존재하지만 그 중 음의 푸아송 비(Poisson's ratio)를 갖는 Chiral Honeycomb 구조가 많이 연구되고 있다. 푸아송 비는 물질이나 구조의 고유한 물성치로 종, 횡 방향의 변형율로 나타내며 이 값으로 외부 조건으로부터의 변형을 예측 할 수 있게 된다. 흔히 푸아송 비는 양의 값을 가지지만 Chiral Honeycomb 구조는 음의 푸아송 비를 가져 기존의 구조와는 다른 기계적 성질을 가지게 된다. 이 논문에서는 Chiral Honeycomb 구조 중에서도 4개의 관절(ligament)를 가지는 Tetra Chiral Honeycomb 구조에 대해 EDISON용 CASADsovler 프로그램을 통해 유한 요소 해석을 수행하여 등가 물성치를 구해 보았으며 기존 실험의 값들과 비교를 통해 해석을 위해 필요한 적절한 대표 체적에 대해 확인해 보았다.

• Journal of architectural history
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• v.20 no.5
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• pp.47-61
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• 2011

This study examined the background and change of building Yeongam eupseong and characteristics and construction method of its spatial structure. The results of this study can be summarized as follows. First, Yeongam eupseong was built for the same purpose of national border defense against the invasion of Japanese army as other Eupseongs were built and it was found first in the literature in the era of King Munjong of Joseon Dynasty with the scale of three gates and 4,369 cheok of castle wall. Such a scale was continued and in particular, according to flat structure, road network and gate position shown in the map, the form and road system of Yeongam eupseong before the 19th century were mostly identical with the current ones. Second, castle wall was built over foundation by using talcum after leveling the foundation soil and castle wall can be divided into outer wall, filling part and inner wall from the section. Outer wall was constructed by inserting and layering pebbles with big irregular stone, filling part was made with talcum and riprap and inner wall with soil in several layers by keeping gradient. This building method showed common features in inserting and layering pebbles for outer wall, use of protruded base and section form compared to Jeollado Eupseong.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.745-752
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• 1996

Wear property of plasma spray coating in $Cr_2O_3$ powder manufatured of spray dry method on the aluminum substrate was inspected for the application of piston-ring of automotive enginel. The plama spray coatings were varied with feed rate and particle size. Used the ball-on disc type tribometer, wear volume, friction, surface rougness were investigated. The delamination of the coating layer were observed with SEM. Also the cross-section of wear track were investigated, using optical microscopy. As a result of experiment, wear mechanism was addressed in the various coating process.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.66-72
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• 2009

In order to forecast the progress of the track irregularity, we should observe the long-term track quality and divide a track into some separated divisions which have homogeneous property. For this, we define the division of track which has homogeneous property as a 'Segment' and manage the 'TQI(Track Quality Index)' using track induction data based on each segment. In this study, we introduce some methods of estimating track quality and figure out the TQIs of sample section using new FRA TQI method. In addition, we conducted a basic study of the forecasting model for the progress of track irregularity by analyzing track maintenance data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.04b
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• pp.400-407
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• 1995

The straightness property is one of fundamental geometric tolerances to be strictly controlled for guideways of machine tools and measuring machines. The staightness measurement for long guideways was usually difficult to perform, and it needed additional equipments or special treatment with limited application. In this paper, a new approach is proposed using the profile matching technique for the long guideways, which can be applicable to most of straghtness measurements. An edge of relativelly sthort length is located along a divided section of a long guideway, and the local straightness measurement is performed. The edge is then moved to the next section with several positions overlap. After thelocal straightness profile is measured for every section along the long guideway with overlap, the global straightness profile is constructed using the profile matching technique based on theleast squares method. The proposed techinique is numerically tested for two cases of known global straightness profile arc profile and irregular profile and those profiles with and without random error intervention, respectively. When norandom errors are involved, the constructed golval profile is identical to the original profile. When the random errors are involved, the effect of the number of overlap points are investigated, and it is also found that the difference between the difference between the constructed and original profiles is very close to the limit of random uncertainty with juist few overlap points. The developed technique has been practically applied to a vertical milling machine of moving table type, and showed good performance. Thus the accuracy and efficiency of the proposed method are demonstrated, and shows great potential for variety of application for most of straightness measuirement cases using straight edges, laser optics, and angular measurement equipments.

• Journal of Korea Multimedia Society
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• v.14 no.12
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• pp.1601-1612
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• 2011

In recent years, advanced in digital technologies have created significant changes in the way we reproduce, distribute and market Intellectual Property (IP). DRM for multicast contents is complicated risk, the further technology development and human demand, this approaching is still being researched by the scientist and all by the company which is conducting in piracy management reduced, and every country has national policy to make this consortium to limit piracy properties, based on this paper research development, just only two approaching to reduce piracy in DRM they are Industrial Property (IP) and Copyright. In this paper, we are not only figuring and analyzing about the processes to reduce and limit the piracy and unprotected copy law but also describing about the encryption process, watermarking and digital signature process algorithms. The basic concepts of this encryption process for web-based multicast content in DRM are implemented in Java. We conduct this method is a computerized through web based application system approaching to reduce unprotected copy and piracy. Which is used in DRM for multicast content in every section, by providing a fundamental in information technology development, we believe this research is reliable to prove that is unprotected copy, and piracy can be reduced by protecting with this paradigm.

• ETRI Journal
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• v.20 no.1
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• pp.46-54
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• 1998

An analysis method of electromagnetic scattering from periodic patch array of double-dipole elements on a grounded dielectric substrate in case of oblique incident and arbitrary polarization is considered. The basis functions are chosen to be entire consinusoidal functions are chosen to be entire consinusoidal functions covering the rectangular shaped domain in which the original dipoles are inscribed, unlike the conventional method in which basis functions are defined only for the conducting element region. To confirm the validity of the proposed analysis method, we calculate the normalized scattered power for two propagating modes and compare the results with those obtained by the previous numerical method for the double dipole elements of rectangular type and parallelogram type which have the property of frequency scanned reflection and polarizer. Good correspondence has been observed between them. Some numerical results such as variation of power and axial ratio of first-order diffracted wave by a periodic array of double-dipole elements are compared with previous results.

• Textile Coloration and Finishing
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• v.27 no.1
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• pp.11-17
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• 2015

Recently, super fiber reinforced composite materials are widely used in many industries due to high mechanical properties. In this study, 2 different types of composite materials were manufactured in order to compare their mechanical properties. Carbon and Aramid fibers were used for reinforcement materials and Bisphenol-A type epoxy resin was for matrix. Two kinds of fiber-reinforced materials were manufactured by RIM(Resin Injection Molding) method. Before manufacturing composite materials, the optimal manufacturing and curing process condition were established and the ratio of reinforcement to epoxy resin was discussed. FT-IR analysis was conducted to clarify the structure of epoxy resin. Thermal and mechanical property test were also carried out. The cross-section of composite materials was observed using a scanning electron microscope(SEM).