• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.1
• /
• pp.329-332
• /
• 2014

The Korean High Speed Electric Multiple Unit (HEMU) train system is soon being applicable to practical use. This new technology is expected not only to reshape the domestic market but also to be exported to overseas markets for high-speed train system. This study aims to prospect demands on the HEMU train technology and to formulate marketing strategies using a text-mining technique, therefore, providing a foundation for successful commercialization of the HEMU train system.

• Journal of Intelligence and Information Systems
• /
• v.10 no.1
• /
• pp.65-75
• /
• 2004

It is notorious that PIN(Personal Identification Number) is used widely for user verification and authentication in networked environment. But, when the user Identification and password are exposed by hacking, we can be damaged monetary damage as well as invasion of privacy. In this paper, we adopt face recognition-based authentication which have nothing to worry what the ID and password will be exposed. Also, we suggest the remote authentication and verification system by considering not only 2-Tier system but also 3-Tier system getting be distributed. In this research, we analyze the face feature data using the SVM(Support Vector Machine) and PCA(Principle Component Analysis), and implement artificial intelligence face recognition module in distributed environment which increase the authentication speed and heightens accuracy by utilizing artificial intelligence techniques.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.16 no.11
• /
• pp.2465-2473
• /
• 2012

Recently, as one of low complexity video encoding methods, DVC (Distributed Video Coding) scheme has been actively studied. Most of DVC schemes exploit feedback channel to achieve better coding performances, however, this causes these schemes to have high decoding delay. In order to overcome these, this paper proposes a new fast DVC decoding method using parity-bit request model, which can be obtained by using bit-error rate, sent by encoder with motion vector, which is transmitted through feedback channel by decoder after generating side information. Through several simulations, it is shown that the proposed method improves greatly the decoding speed, compared to the conventional schemes.

• The KIPS Transactions:PartC
• /
• v.11C no.7 s.96
• /
• pp.993-998
• /
• 2004

As Worm Virus & DDoS attack appeares, the targets and damage of infringement accidents are extending from specific system or services to paralysis of the network itself. These attacks are expending very frequently and strongly, and ISP who will be used as the path of these attacks will face serious damages. But compare to Worm Virus & DDoS attack that generally occures in many Systems at one time with it's fast propagation velocity, network dimensional opposition is slow and disable to deal with the whole appearance for it is operated manually by the network manager. Therefore, this treatise present devices how to detect Worm Virus & DDoS attack's outbreak and the attacker(attacker IP adderss) automatically.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.11
• /
• pp.1013-1020
• /
• 2011

This paper deals with the tracking problem of a moving target using multiple unmanned aerial vehicles. A decentralized extended information filter is designed to cooperatively estimate the position and the velocity of the moving target. The extended information filter is adopted to consider the range and the line-of-sight angle as measurement data. The decentralized scheme is applied to enhance the estimation performance using the information provided by other vehicles. Numerical simulation is performed to verify the tracking performance of the proposed decentralized filters.

• Journal of the Korean Institute of Gas
• /
• v.8 no.2 s.23
• /
• pp.8-14
• /
• 2004

This study analyzed dispersion characteristics and toxic effect in the small-scale continuous release of chlorine gas. We found that the Gaussian model using the Briggs' dispersion coefficient and the effective release height was better predicting experiments than the BM model. From chlorine concentrations calculated by Gaussian model, simulation results showed that the dispersion of chlorine was more affected by atmospheric stability and wind speed than release rate and that the toxic effect of chlorine gas was similar to the effect of parameters on chlorine dispersion. From effected areas with toxic criteria, damaged areas could be estimated to protect human.

• The KIPS Transactions:PartC
• /
• v.10C no.5
• /
• pp.617-624
• /
• 2003

This paper proposes a modified DCPC (Distributed Constrained Power Control, M-DCPC) algorithm that can improve the performance of a CDMA power control system. The control performance of the proposed method is verified using two performance measures : the SIR response of each mobile and the outage probability in a cell. As regards the SIR response, in simulations, the M-DCPC algorithm has shown a faster convergence and lower overshoot in transient time than the other power control algorithms when the desired SIR value was varying. For the outage probability. M-DCPC converged to a fixed outage rate faster than CSOPC while also maintaining the system capacity to make as high a connection as CSOPC. In particular, when the desired SIR was varying, CSOPC showed an abrupt outage probability increase during the desired SIR Increase, yet M-DCPC was unaffected.

• Geophysics and Geophysical Exploration
• /
• v.9 no.4
• /
• pp.304-315
• /
• 2006

We have examined the applicability of f-k analysis to the GPR direct wave measurement for water content to characterize vadose zone condition. When the vadose zone consists of a dry surface layer over wet substratum, we obtained f-k spectra where most of the energy is bounded by the air and dry soil velocities. In this case, dry soil velocity was successfully estimated by using high frequency data. On the other hands, when wet soil overlies dry substratum, the f-k spectra show a contrasting response where most of the energy travels with the velocity bounded by dry and wet soil velocities. In this case, the radar waves are trapped and guided within wet soil layer, exhibiting velocity dispersion. By adopting modal propagation theory, we could formulae a simple inversion code to find two layer's dielectric constants as well as layer thickness. By inverting the velocity dispersion curve obtained from f-k spectra of synthetic modeling data, we could obtain good estimates of dielectric constants of each layer as well as first layer thickness. Moreover, we could obtain more accurate results by including the higher mode data. We expect this method will be useful to get the quantitative property of real subsurface when the field condition is similar.

• The Korean Journal of Applied Statistics
• /
• v.27 no.7
• /
• pp.1171-1185
• /
• 2014

Rhipe that integrates R and Hadoop environment, made it possible to process and analyze massive amounts of data using a distributed processing environment. In this paper, we implemented multiple regression analysis using Rhipe with various data sizes of actual data and simulated data. Experimental results for comparing the computing speeds of pseudo-distributed and fully-distributed modes for configuring Hadoop cluster, showed fully-distributed mode was more fast than pseudo-distributed mode and computing speeds of fully-distributed mode were faster as the number of data nodes increases. We also compared the performance of our Rhipe with stats and biglm packages available on bigmemory. The results showed that our Rhipe was more fast than other packages owing to paralleling processing with increasing the number of map tasks as the size of data increases.

• Journal of the Korean Geophysical Society
• /
• v.5 no.3
• /
• pp.233-245
• /
• 2002

The spectral-analysis-of-surface-waves (SASW) method is a nondestructive testing method based upon generation and detection of elastic stress waves. SASW is widely used as one of the techniques to determine stiffness profile in engineering geophysics. The essential steps involved are construction of an experimental dispersion curve from data collected in situ, and inversion of the dispersion curve to determine the stiffness profile. The main object of this study is to derive an analytical Jacobian for the inversion. If we set the subsurface to N homogeneous layer, it could save 2N times Jacobian calculation compared to numerical jacobian calculation during inversion. To reconstruct a stiffness profile, constrained damped least square method was applied for the inversion. The algorithm was tested for the numerical data and for the real asphalt and tunnel data, which were able to verify the stiffness profile. The stiffness profile reconstructed by the algorithm showed the possibility to appraise the soundness of tunnel with applications SASW.