• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.2
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• pp.112-120
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• 1998

A nondestructive evaluation technique was developed for the quantitative determination of the reinforcement volume fractions in particulate reinforced metal matrix composites. The proposed technique employed a composite micromechanics which accounts for the microstructure of the composite medium together with the measurement of anisotropic electrical conductivity. When the measured conductivity was coupled with the theoretically predicted conductivity, the unknown reinforcement volume fraction was calculated. An analytical model based on the Mori-Tanaka method was described which relates the NDE signatures to the composite microstructure. The volume fractions were calculated using eddy current measurements made on a wide range of silicon carbide particulate ($SiC_p$) reinforced aluminum (Al) matrix composites. The calculated $SiC_p$ volume fractions were in good agreement with the measured volume fractions in the range of 0-30%. The technique was also found to be effective in estimating the total volume percentage of reinforcement and intermetallic compound formed during the processing stage.

• Archives of design research
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• v.19 no.1 s.63
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• pp.59-68
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• 2006

Scarf has played an important role not only as keeping warm of human body but also as accessory of clothes. These days with taking a growing interest of accessory, scarf had thrown off a subsidiary part and gradually had a leading place which guides the overall mode of fashion. Because scarf design of Korea does not get out of imitation step of foreign countries brands it is necessary to develop the scarf design which can show the cultural identity and originality of Korea in international society. Therefore in this study, I chose lotus flower patterns expressed on Buncheon pottery and Korean traditional patchwork cloth as the subject material of scarves design development, and my intention for this study is to develop scarves designs of Korean images by adding modern scenes. For that, first I researched lotus flower patterns expressed on Buncheon pottery and Korean traditional patchwork cloth. Among those materials, I selected to had been presented modern image. And by using computer design program of adobe illustrator 10.0 I designed the basic patterns of three types and developed the square scarves design and rectangle scarves design with those.

• School Mathematics
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• v.17 no.1
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• pp.119-134
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• 2015

The purpose of this study was to specify knowledge and skills that are expected to be learned by students worldwide at the elementary level of Mathematics. This was achieved by extracting knowledge and skills commonly expected to know and perform in elementary school level by analyzing elementary math curriculum of twelve countries that vary geographically and economically. Based on the data gathered and analyzed, the common domains extracted from this study in elementary level Mathematics include Number and Operations, Geometry, Measurement and Data. And knowledge and skills that children are expected to achieve in each domain by the end of primary school were listed. This research showed that for elementary level Mathematics, the majority of the curricula had the commonalities in Number and Operations, Geometry, Measurement and Data. Though this study had the limitations of analyzing curriculum documents open to public, this study will offer the ground for discussion on the elementary mathematics education in a global context.

• Journal of the Korean Institute of Gas
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• v.10 no.2 s.31
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• pp.40-46
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• 2006

In this paper, the optimized design of a rectangular O-ring groove has been analyzed for a maximum Cauchy stress and maximum strain using the Taguchi method. This method may efficiently optimize the design parameters for an O-ring groove of a LPG filling unit. The computed FEM results indicate that the optimized design parameters can only be drawn by nine experimental numbers of iterations when the Taguchi design technique has been employed with a finite element method. This means that the Taguchi design method is very useful for the optimization design of O-ring rectangular groove geometry. Based on the computed FEM results by the Taguchi design technique, the dimensions of a groove geometry are given as h=2.5 mm, d=2.74 mm, c=0.15 mm, and w=3.0 mm. In this study, the initial compression ratio of O-rings is recommended as 8.7% for a gas supply pressure of 18 $kg/cm^2$.

• Archives of design research
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• v.16 no.2
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• pp.171-178
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• 2003

The visual, sensible and social situation that the modern digital technologies create became the background for the works of architects in extreme modernism and their space modeling suggested another possibility that was emancipated from the restriction of a property of matter and gravity in the existing space. The architecture design process using the digital technology has been attempted in diverse ways and summarized with several characteristics such as displacement, nonlinear space, flexibility of space and non-Euclidean geometry system. However, the conceptual and very technical design process that is called as digital architecture has been indiscriminately used with mixed meanings and the common features and differences between works and theories are not studied. This study aims to classify and identify the digital architecture by type as analyzing the non-linear composition process that is common in the digital architecture.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.17 no.2
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• pp.97-104
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• 1999

Digital elevation models(DEMs) represent an important data base for orthophoto generation The quality of a DEM depends on the geometrical accuracy of the original point or line data. This study analyzes the effects of grid space and scanning resolution in DEM creation with image matching method. The less standard deviation of DEM error was introduced when we adopted small grid space, but no effects in scanning resolution. Based on the bias error analysis of the DEM, we found that the error of a large scale of aerial photograph was bigger than that of a small scale case, and that such error mainly came from the closed area in large scale photographs. In order to reduce the closed area, the experiment has been conducted using multi scale and different overlap of aerial photo images. The result shows that the size of closed area and the shaded area has been dramatically decreased due to the adoption of multi scale aerial images instead of a couple of stereo images.

• Journal of the Korean Society for information Management
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• v.17 no.3
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• pp.7-20
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• 2000

Many organizations have developed their own information systems not only for internal efficiency but also for effectiveness of external customer services. The infusion of powerful information networks into business environments is beginning to have a profound impact on the nature of governance between buyers and sellers in the market place. One of the most effective service tools for their customers is the use of information technology. The web technology is rapidly becoming one of the most effective online customer service tools toward strategic competitive advantage. In order to gain competitive edge, organizations must have effective web sites for customer services. A study on web service development phase has been conducted and present states of web usages by Korean, US., Japanese companies are surveyed. Cases of business web sites are empirically analyzed in order to compare the different levels of web site application in three countries. Conclusively, countries with longer experience with internet has more advanced level of web application such as business transaction and internet process innovation. In order to support effective web site planning, organizations have to understand their current position in Internet application and form strategies for e-business.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.3
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• pp.175-185
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• 2020

The six-DOF aerodynamic coefficients of a missile entail inherent physical gradient constraints originated from the geometric characteristics of a cylindrical fuselage. To effectively adopt the freely available gradient information in aerodynamic coefficients modeling, this research employed gradient-enhanced (GE) Gaussian process. To investigate the accuracy of aerodynamic coefficients predicted with gradients information, we compared two Gaussian-process-based models: ordinary and GE Gaussian process models with and without gradient information, respectively. As a result, we found that GE Gaussian process models were able to comply with imposed gradient information and more accurate than ordinary Gaussian process models. However, we also found that GE Gaussian process modeling cannot handle gradient information continuously and ends up with more samples due to additional gradient information.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.6 no.1
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• pp.3-12
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• 1988

The objective of this paper is to study the characteristics of combination method to correct both angle and distance errors simultaneously based on the least square adjustment methods. Changing the standard errors of distance and angle, the simulation errors of triangultion, trilateration, and combination result in some 39.8%, 33.9%, and 26.3% respectively. As the above, combination method shows more consistent accuracy than other methods. When considering the weight factor about error elements with independence, the diminishing rate of simulated average standard error represents a various change in each method. But considering them simultaneously, it shows a remarkable rate of diminishing 75.5%, 74.1%, and 69.2% in each method. And also, by growing the weight factor, accuracy of triangulation method is growing, whereas that of trilateration is diminishing. Therefore, determining the reasonable weight factors of distance and angle errors simultaneously in the analytical combination method, this method is expected to be one of more accurate and more effective methods for determining horizontal positions on the earth.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.2
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• pp.199-210
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• 2012

This paper is designed to put forth a proposal for configuration of an optimized observation network based on GNSS CORS with a view to continued monitoring of crustal deformation in the East-Asian region. For this purpose, a comprehensive analysis of the results of the testing of various forms of GNSS CORS observation network tentatively constructed based on the Asia-Pacific IGS station has confirmed that geometrically arranged minimum five and ten or more reference points and an EAREF, constructed with a baseline length no longer than 2,500km, can produce an optimum outcome. And an EAREF-applied analysis on the effects of the Great Eastern Japan Earthquake of March 2011 shows that there were conspicuous positional movements in Japan and Korea while there was no significant movement in other regions.