• Journal of the Korean Geotechnical Society
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• v.18 no.1
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• pp.17-28
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• 2002

Tunnel construction is a complex three dimensional operation. Since, however, it is neither possible nor useful to simulate all conditions and parameters in detail, a simplified two dimensional model is commonly employed in practice. The simulation of three dimensional conditions by a two dimensional model should use empirical parameters. The numerical predictions indicate that analysis results are highly dependent on the parameters. An improved modelling method based on time was adopted to account for three dimensional effect at the tunnel heading and time dependent nature, and used to perform an analysis of tunnelling in decomposed granite. The effects of weathering degree, tunnel shape and multi-drift excavation were investigated by using the method. It is identified that a structural benefit can be obtained by adopting a horse-shoe-shaped cross section with multi-drift excavation in mixed-force ground condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1443-1448
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• 2006

As computers and networks become popular, distributing information on the Internet is common in our daily life. In the past, e-mail has been the primary choice of exchanging information but messengers are gaining popularity abroad and domestically because of their nature of getting immediate responses. Information leakage by invasion that is enemy of evil in communication of communications division Server and Agent between each agents that become burden of communication for effective administration of data for most of existing messenger is becoming an issue. In this paper, we design a secure messenger system that could be obtained maximum security. It use ECC based on ElGamal methodology using PKI for secure communication. For the message encryption and decryption between the same group non, each group is kept distinct by drawing an elliptic curve and an arbitrary point is chosen on the curve.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.137-145
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• 2010

Many research works are actively being done due to the 3D contents production technology for global competition through the world. In korea, many experts have taken notice of high quality 3D movies produced by Hollywood. Recently, 3D movie "Avatar" advanced 3D computer graphics based digital production technology is heavily influencing the contents industry in global market. Therefore, In this paper, the success factor of "Avatar"has to be analyzed. Also, the analysis of 3D contents production environment of the domestic and Hollywood is performed. Based on that, we analyzed the factors of threat and opportunity of the Korean 3D contents. Also, Based on the statistical data analysis of the korean film commission, favorable reactions of the korean movie and the government's powerful policy direction, we proposed the successful possibility of the korean 3D contents.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.459-469
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• 2010

Knowledge-based society requests the ability to reuse existing knowledge beyond acquirement and utilization of universal knowledge. The present education of computer, on the other hand, is biased only teaching how to use software. But it does not appropriate for the education to boost various and creative thinking. Thus, this paper carried out research on creativity to be treated in the goal of the 7th Educational Curriculum. Also it selected and analysed computer programming languages-'LOGO' and 'Scratch'. Furthermore, it develops a training material and applies to elementary students in schools. The result that it compares and analyzes the effect that each languages influence to creativity of students, both of them help to develop creativity. Especially 'LOGO' made a positive impact on fluency, 'Scratch' did on ness and resistance.

• The Journal of the Korea Contents Association
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• v.10 no.7
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• pp.233-243
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• 2010

Thanks to the rapid advance of modern technology in industrial society, economic and material abundances have not only caused a variety of cultural industry to develop but also brought about the development of beauty treatment industry. Like this, the industry has continually expanded into the public rapidly by forming a new beauty trend along with the growth of mass media such as T.V, advertisement, vogue magazine, and film. And make-up is also broadening its artistic areas by utilizing various expression skills and consistently changing with beauty trends, which has influences on Make-up Illustration. As a result, it has been recognized as a new conception of 'art' expanding in interpretation of communicating with the masses under condition of modern culture and stressed in its part more and more. It is expected that Make-up Illustration playing an important role in the exchange of fashion trend information between beauty treatment industry and people will be studied in different-image-expression ways to raise its artistic value and be a useful material for research and creation activities in the foreseeable future by Make-up Illustration made of computer graphics.

• Tunnel and Underground Space
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• v.9 no.4
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• pp.288-295
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• 1999

Concentrated stresses due to the underground tunnel excavation easily cause many problems such as yielding, popping, and failure at the immediate roof, wall and floor of tunnel. Therefore, it is very important to predict the possibility of these problems when a tunnel is excavated underground. There are two typical methods to predict these problems. The one is to predict problems from the analysis of field monitoring data and the other is to predict them from computer simulations using good site investment data. Using the second method, this study attempted to describe the time-dependent or progressive manner of immediate roof and wall due to the underground tunnel excavation. An iterative technique was used to represent progressive failure of rockmass with the Hoek and Brown theory. By developing and simulating three different shapes of twin tunnels, this research estimated the proper size of critical pillar width between tunnels, distributed stresses on the tunnel walls, and convergences of tunnel crowns. Moreover, results out of progressive failure technique based on the Hoek and Brown theory were compared with the results out of Mohr-Coulomb theory.

• Tunnel and Underground Space
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• v.26 no.4
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• pp.266-273
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• 2016

We have numerically modeled thermal evolution of Ulleung Island after an emplacement of magma chamber. The disk-shape magma chamber is assumed to locate at 2.9 km beneath the island and has a diameter and a thickness of 10 km and 300 (or 600) m, respectively. The geothermal gradients evaluated from the numerical modeling coincide well with the range of the geotherms (${\sim}95^{\circ}C/km$) observed from the well logging. Although there are limitations in the application of the numerical results directly to the interpretation of the observed geotherms, we believe that an existence of a hot magma chamber in molten or in solidified state is the most plausible explanation for the observed geotherms.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.429-438
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• 1994

Three-dimensional analyses of multistory structures with wings using finite element models require tedious input data preparation, longer computation time. and larger computer memory. So this study lays emphasis on the development of efficient analysis models for a three-dimensional multistory structure with wings, including in-plane deformation of floor slabs. Since a three-dimensional multistory structure with wings is regarded as a combination of wing structures and their junction in this study, the proposed analysis models are easily applicable to multistory structures with plans in the shape of letters Y, U, H, etc. Dynamic analyses results obtained using proposed models are in excellent agreement to those acquired using three-dimensional finite element models in terms of natural vibration periods, mode shapes and displacement time history.

• Archives of design research
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• v.20
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• pp.51-58
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• 1997

This paper aims to aid a practical evaluation for screening out the design proposais under applying the IRDS system, which is developed a computer aided industrial design system as a computer application system. In this study, the author adopted 3 evaluation methods with criteria which have quantitative and qualitative attributes : the Intuitive Evaluation Methods(X), the Accumulative Evaluation Method(Y), the Benchmarking Evaluation Methods(Z). The results show that the 3 Methods have reciprocal relationships under reliability(r=0.0001). In analysis on the properties of the evaluation methods, the Evaluation Method (X) shows rapidity especially, the Evaluation Method (Y); relativity, the Evaluation Method(Z); importance respectively. The correlation analysis between the evaluation methods makes the null hypothesis denying, then we could adapt the research hypothesis. Therefore the correlation between them has positive relationship, and it shows thicker than the result of the 1st study.

• Journal of the Korean Society for information Management
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• v.33 no.1
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• pp.139-160
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• 2016

This study suggested improvements after analyzing the effectiveness of "A" university library. So, this study analyzed the effectiveness of E-group "A" university, and measured the effectiveness, classifying with three conditions about input & output and factors and conditions about regional categories. As a result, it is necessary to operate E-group 38 university libraries and "A" University library by increasing input factors to increase outputs. The improvements are as followings. First, it is necessary to stir up member's recognition on libraries. To this, there is a legal system for university library. Second, it is necessary to include library use education in curriculum. Third, it is necessary to prepare complex space so that the members can borrow books and use it for cultural space and rest space.