• Journal of the Korea society of information convergence
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• v.6 no.2
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• pp.45-49
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• 2013

Electrocardiogram(ECG) signal noise as well as conducting other bio-signal measurement were generated. It was intened to enhance the accuracy of cadiac disease diagnosis with removing signal white-noise. Sampling signal was made with generating white-noise. The noise were removed using wavelet transforms and thresholding. Removed noise were compared numerical using SNR(signal to noise ratio). The results compared SNR showed that SURE method was 5.931, 4.9301 in 3, 5dB noise, uninversal was 3.6590, 1.9698 in 7, 9dB noise. De-noising by Thresholding removed noise effectively. ECG signal is expected to improve the accuracy of cadiac desease dianosis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.9
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• pp.908-914
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• 2013

A shaped Cassegrain antenna is designed from the condition of the same path length at the equi-phase surface by using the conservation of energy and Snell's law. In order to improve the phase error efficiency of aperture surface, the surface profile of the main and sub-reflectors is found to satisfy the power distribution and the equi-phase condition at the aperture surface. The sidelobe levels of 36.4 dB and 33.9 dB are achieved at the AZ and EL planes, respectively from numerical calculation by physical optics method at Ku band and the directivity of designed antenna is 10 percent greater than that of conventional antenna.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.207-214
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• 2022

A prediction model is proposed for a blast load acting on a column component because of an external explosion. The model can predict the pressure-time histories acting on a column using the fitting curves established from a database composed of finite-element (FE) analysis results. To this end, 70 numerical simulations using the commercial software AUTODYN were performed by changing the column width. To confirm the performance of the proposed model, pressure-time histories estimated from an existing empirical formula and the proposed model were compared based on the FE analysis results. It was verified that the proposed model can more precisely predict the pressure-time histories compared with the existing model.

• Journal of applied mathematics & informatics
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• v.31 no.3_4
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• pp.343-352
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• 2013

In this paper, we give a formula of $(P+Q)^D$ under the conditions $P^2Q+QPQ=0$ and $P^3Q=0$. Then applying it to give some results of block matrix $M=(^A_C^B_D)$ (A and D are square matrices) with generalized Schur complement is zero under some conditions. Finally, numerical examples are given to illustrate our results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.8
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• pp.607-614
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• 2013

In this work we investigate the power of power law in the VoD service over IP network. Especially, we show that the power of power law is strong in the location of the contents storage for the VoD service and its impact on the link dimensioning. This work first shows the instance of the power law in the popularity of the video contents from the real data for the IPTV service. After that we propose an analytic model that characterizes the behavior of customers in accessing the video servers as well as the power law in the viewing pattern. Finally, we show the impact of the power law by proposing a model for the cost as well as link dimensioning. Via numerical experiment we show the implication of the proposition.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.4
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• pp.8-17
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• 1999

In this paper, a proposal for improving the performance of IF in-phase combiner is presented in view of simple hardware design and good performance for space diversity application. By adding the stable normalization circuit to the phase detector, better performances are obtained even for a severe notch depth of 30 dB. To check the validity of this proposal, various results based upon numerical simulation and laboratory test are presented here in conjunction with 64-QAM digital radio relay system.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.3
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• pp.9-16
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• 1997

A 23GHz 1-stage LNA was designed by using new topology of coupled line type with EEsof softwares and modified by using MPIE numerical analysis. The parallel coupled filter-type matching sections give impedance matching and DC blocking simultaneously, and have small discontinuities. This matching scheme has simple structure in the design process and give small error. The EFT chip was directly attached to the ground metal. The designed LAN gives 6.2dB gain and 2.5dB noise figure without considering the loss of connectors. Through these results, it was verified that our design process, matching schemes and fabrication technologies was valied for developing 20GHz-band LNA.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.4
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• pp.92-103
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• 1993

In this paper, we propose an adaptive classifier based on uncertainty of features for 3D planar object recognition. First, we investigate the uncertainty of depth information and the feature values of 3D planar object by numerical method. And, we observed that the statistical behavior of feature is dependent on the position and orientation of objects. After that, the approximation of the statistical behavior is executed. Subsequently, the recognition procedure is executed by the adaptive classifier. By computer simulation, we confirmed that the proposed classifier is useful for 3D planar object recognition.

• Tunnel and Underground Space
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• v.30 no.4
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• pp.335-358
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• 2020

We present a numerical model to simulate coupled hydro-mechanical behavior of fault using TOUGH-FLAC simulator. This study aims to develop a numerical method to estimate fluid injection-induced fault reactivation in low permeability rock and to access the relevant hydro-mechanical stability in rock as part of DECOVALEX-2019 Task B. A coupled fluid flow and mechanical interface model to explicitly represent a fault was suggested and validated from the applications to benchmark simulations and the field experiment at Mont Terri underground laboratory in Switzerland. The pressure build-up, hydraulic aperture evolution, displacement, and stress responses matched those obtained at the site, which indicates the capability of the model to appropriately capture the hydro-mechanical processes in rock fault.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1247-1248
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• 2013