• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.3
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• pp.321-339
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• 2014

This paper concerns the development of a knowledge-based tunnel design system within the framework of artifical neural networks(ANNs). The system is aimed at expediting a routine tunnel design works such as computation of segment lining body forces and stability analysis of selected cross section. A number of sub-modules for computation of segment lining body forces and stability analysis were developed and implemented to the system. It is shown that the ANNs trained with the results of 3D numerical analyses can be generalized with a reasonable accuracy, and that the ANN based tunnel design concept is a robust tool for tunnel design optimization. The details of the system architecture and the ANNs development are discussed in this paper.

• Journal of Korea Multimedia Society
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• v.11 no.2
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• pp.228-236
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• 2008

Recently augmented reality technology has been researched to view the virtual shape of buildings before construction or cultural heritages under recovery. Those researches used special devices or markers that are not applicable in long distanced outdoor environment. Also the server had to compute a lot of transformations for the location changes of virtual objects. This paper proposed a mobile augmented reality system that uses GPS and accelerometer sensors in order to compute the virtual object's locations without using markers. The server determines the position and orientation by comparing the GPS data obtained from the client with the predefined 3D object informations in the server. If the server sends the virtual object informations such as the position, orientation and matching information, then the client matches the virtual object on the screen of mobile camera phone. In addition, the client computes the transformations of location change detected by the accelerometer derived from the user's movement without additional connection to the server.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.20 no.3
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• pp.347-352
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• 2007

Eigenvalue reduction schemes approximate the lower eigenmodes that represent the global behavior of the structures. In the previous study, we proposed a two-level condensation scheme (TLCS) for the construction of a reduced system. In the first step, the selection of candidate elements by energy estimation, Rayleigh quotient, through Ritz vector calculation. In the second step, the primary degrees of freedom are selected by the sequential elimination method from the degrees of freedom connected to the candidate elements in the first step. In the present study, we propose TLCS combined with iterative improved reduced system (IIRS) to increase accuracy of the higher modes in the intermediate range. Also, it is possible to control the accuracy of the eigenvalues and eigenmodes of the reduced system. Finally, numerical examples demonstrate the performance of the proposed method.

• The Journal of Society for e-Business Studies
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• v.8 no.3
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• pp.241-257
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• 2003

XML is a global standard for the Internet and e-business, and its use is growing in proportion to the spreading speed of e-Commerce. Thus, a policy for providing more safe security service for exchanging e-documents within e-Commerce is necessary. XKMS, one of XML security specification, defines the protocol for distributing and registering public keys for verifying electronic signatures and enciphering e-documents of e-Commerce applications with various and complicate functions. In this paper, we propose X-KISS service reference model and implement service component based on standard specification. Also describes the analysis and security of XML key information service for safe e-Commerce, paying attention to the features of XML based security service. This reference model supported include public key location by given identifier information, the binding of such keys to identifier information. The client service component controls the number of locate threads and validate threads to analyze the minimum requirements of real-time key retrievals. This service modeling offers the security construction guideline for future domestic e-business frameworks.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.101-112
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• 2015

This study was conducted to predict greenhouse gas (GHG) emission from a radish field by future climate change scenario. A radish field located at Chuncheon-si Gangwon-do was selected, and A1B Special Report on Emission Scenario (SRES) of the IPCC (Intergovernmental panel on climate change) was applied to simulate the future potential climate change. Rainfall and temperature data were predicted to be increased by 8.4 % and 1.9 % in 2040s, 35.9 % and 27.0 % in 2060s, 19.2 % and 30.8 % in 2090s, respectively, compared to the climate data in 2010s. The $N_2O$, $CO_2$, and $CH_4$ emission were estimated to be increased by 0.4 up to 2.4 kg/ha/yr, by 500.5 up to 734.5 kg/ha/year, and by 29.4 up to 160.4 kg/ha/yr, which were resulted from the global warming potential (GWP) of 14.5~21.7 $CO_2$/ha/year caused by the amount changes of rainfall, temperature, manure amendment, and fertilizer applied in fields. One distinct feature of the study result was that the changes of $N_2O-N$, $CH_4-C$ and $CO_2-C$ with future potential climate change simulation were varied by soil texture. Therefore it was concluded that there is a need to apply appropriate amount of manure amendment needs and to consider soil texture as well.

• Journal of Digital Convergence
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• v.14 no.10
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• pp.311-317
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• 2016

In a smart commerce market, customers are seeking customized shopping services optimized for personal tastes and customized shopping experiences based on customers' tastes. Accordingly, individually customized services are needed more than anytime now. According to this demand, companies provide messaging services to the consumer, but do not include a personalized service for each individual. The purpose of this study is to combine the techniques of personalized services with messaging services and presents system construction plan and integrated model system for corporate messaging services and thereby possible are maximizing marketing effects and analyzing effects of cost savings. Applying the operation of the integrated model is proposed and message transmission scheme through effective personalization can be applied to personalized model using the personalized information according to customers' requirements. The integrated model of personalization on this study is expected to be highly effective when combined with the search service.

• Composites Research
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• v.28 no.1
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• pp.15-21
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• 2015

The purpose of this paper is to investigate the current trends of composite applications in the marine and leisure fields and to study the development of 33ft class America's cup training CFRP sailing yacht. In the field of marine and leisure, composite materials have been just used to marine and leisure structures, recently. Especially, since the America's cup of sailing yacht racing has required the light weight and high mechanical performance to make a high speed, CFRP have been recognized as the critical material to construct the racing yacht structures. To establish the process of CFRP racing yacht construction, the design optimizations and production methods of carbon mast and CFRP yacht hull were discussed in this paper. Finally, the constructed CFRP sailing yacht exhibited high performance as the racing yacht through the sailing test.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.350-362
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• 2017

The Eulerian nearshore current model is more advantageous than the Lagrangian model in the way that numerical results from the Eulerian model can be directly compared with the measurements by the stationary equipment. It is because the wave mass flux is not included in the computed mass flux of Euleran nearshore current model. In addition, the Eulerian model can simulate the longshore currents with depth varying parabolic profile. However, the numerical models proposed by different researcher have different forms of the wave stress terms. For example, wave stresses in Newberger and Allen's (2007) model is constant over the depth, while those of Chun (2012) are vertically distributed. In the present study, these wave stress terms were compared against Hamilton et al.'s (2001) laboratory experiments to see the effects of different wave stress terms performed on the computation of nearshore currents.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.1
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• pp.55-64
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• 2015

Wind turbine market is showed height growth rate of about 30% for year, and is increasingly growing. Total rate of domestic wind turbine installation is showing share of 0.2% of the global market that is 380MW. However, wind turbine installed in domestic are foreign product more than 90%. Similarly, Datalogger of pretest system for ocean wind turbine plant installation has been leaked huge cost to abroad by mostly abroad company product. In this paper, we proposed pretest weather resource measurement system for efficiency and investment cost cutting of wind turbine construction work. Preset weather resource measurement system is ocean weather resource measurement datalogger based on wireless communication(wifi) that have consist of hardware and software(wind rose) that is able to monitoring as datalogger of wireless bridge and battery state, wind direction, wind speed, temperature, humidity, radiation around weather tower and is able to analysis of measured data.

• Journal of the Korean Geographical Society
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• v.37 no.5
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• pp.511-521
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• 2002

Coastal sand dunes in West coast of Korea are under stress. Due to the newly constructed Seohaean(West Coast) Highways, the number of visitors and the anthropogenic pressures will keep rising in near future. Sea level rise due to the global warming may cause a lot of damage to the natural resources and residents of coastal area. Therefore, many countries including United States are doing nationwide coastline survey using highly sophisticated methodology. In this study, high resolution IKONOS satellite images along with aerial photographs taken since 1960's have been sequentially analyzed using GIS software (Erdas Imagine 8.3). Onsite monitoring has been performed at the 31 measuring points in 10 beaches since the May of 2001 in order to measure the sand budget. Post-construction monitoring after installation of sand fences is also being done on sites regularly. Restoration works seem to be effective at this moment.