• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.161-167
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• 2008

This paper describes the overview of spectrum requirement estimation recommended in ITU-R Rec. M.1390 and [IMT.METH] and its difference for the IMT mobile service, and a (IMT.METH) methodology is applied to the spectrum estimation of the recent IMT service. The traffic model and traffic calculation algorithm is briefly described for the carried traffic which is determined in terms of the offered traffic, system rapacity, and the criteria of quality of service. And the spectrum requirement demand which is required from year 2010 to year 2015 is calculated as an example for the IMT service which is recently operated and deployed in the current Korean market after obtaining the reasonable market data and the ITU market prediction data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.3
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• pp.257-263
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• 2009

Recently, as the 3G services of Korea have stepped into the developing stage and the traffic has been rapidly increasing, the spectrum requirements have been getting very large. Therefore spectrum reforming is considered actively and firstly exact methodology of spectrum requirement estimation is needed. But existing methodology depends on the future's service forecast than the present substantial data. This paper proposed the exact methodology of spectrum requirement estimation is based on the real data. So this paper analyzed the characteristics of Korean mobile communication traffic based on the real data and the algorithm suitable for estimation of spectrum requirements for 3G mobile communications, and calculated the parameters needed to estimate the spectrum requirements. Based on the traffic parameters of December 2007, simulations to Bet the estimation of annual spectrum requirements were implemented for the two different cases: one of which is 44 % annual increase in the data traffic and the other is 21 % annual increase. The simulation results show 90 MHz for the first case and 60 MHz for the second case in December 2011.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.10
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• pp.858-864
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• 2012

In South Korea, to effective and systematic response to disasters, the government will build wireless communication network for PPDR(Public Protection and Disaster Relief) on a national level by 2015. To do it, as MOPAS(Ministry of Public Administration and Security) requested the new frequency assignment for PPDR, KCC(Korea Communications Commission) has been examined new frequency allocations about TETRA and WiBro technologies. In this paper, we were defined the technical parameters, were estimated the spectrum of TETRA-TRS requirements for Korean wireless communication of PPDR based on M.2033 methodology recommended by ITU-R.

• The Journal of the Acoustical Society of Korea
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• v.3 no.1
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• pp.25-35
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• 1984

This paper analysis the Dynamic Time Warping algorithms for time normalization of speech pattern and discusses the Dynamic Programming algorithm for spoken Korean isolated digits recognition. In the DP matching, feature vectors of the reference and test pattern are consisted of first three formant frequencies extracted by power spectrum density estimation algorithm of the ARMA model. The major differences in the various DTW algorithms include the global path constrains, the local continuity constraints on the path, and the distance weighting/normalization used to give the overall minimum distance. The performance criterias to evaluate these DP algorithms are memory requirement, speed of implementation, and recognition accuracy.

• Korean Management Science Review
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• v.30 no.1
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• pp.125-137
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• 2013

The U.S. Army is capable and ready to deploy full-spectrum armed forces anywhere in the world as we have seen in Iraq and Afghanistan. This commitment is within the realm of logistics support that the readiness to support MRE(Meal Ready to Eat), according to the environment where the operation is on going. ROKA(Republic Of Korea Army) proceeds with the program to develop and reserve various MRE under the assumption of distinctive warfare operating environment. This study investigates to determine the amount of MRE consumption within various operating environment and details are as follows. First we ponder the concept of MRE and identified problems of the existing program. Second we also establish feeding rations by the types of MRE that is the base for calculation. Third we introduce MRE consumption algorithm and formula. Fourth and last we have applied our model to the program and analyzed the results. The present state of the estimation didn't reflect various warfare operating environment. Therefore we simulates theater wargame model to determine the consumption under various warfare operating environment. The result of this study is anticipated to contribute largely to the force enhancement as it mirrors of every circumstances of operating environment.

• Journal of Electrical Engineering and Technology
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• v.9 no.5
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• pp.1753-1761
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• 2014

Due to the inherent inhomogeneous and anisotropy nature of the composite materials, the detection of internal defects in these materials with non-destructive techniques is an important requirement both for quality checks during the production phase and in service inspection during maintenance operations. The estimation of the time-of-arrival (TOA) and/or time-of-flight (TOF) of the ultrasonic echoes is essential in ultrasonic non-destructive testing (NDT). In this paper, we used split-spectrum processing (SSP) combined with matching pursuit signal decomposition (MPSD) to develop a dedicated ultrasonic detection system. SSP algorithm is used for Signal-to-Noise Ratio (SNR) enhancement, and the MPSD algorithm is used to decompose backscattered signals into a linear expansion of chirplet echoes and estimate the chirplet parameters. Therefore, the combination of SSP and MPSD (SSP-MPSD) presents a powerful technique for ultrasonic NDT. The SSP algorithm is achieved by using Gaussian band pass filters. Then, MPSD algorithm uses the Maximum Likelihood Estimation. The good performance of the proposed method is experimentally verified using ultrasonic traces acquired from three specimens of carbon fibre reinforced polymer multi-layered composite materials (CFRP).

• Proceedings of the KOSOMBE Conference
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• v.1997 no.05
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• pp.275-278
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• 1997

Standard methods estimating the power spectral density(PSD) from an irregularly sampled cardiac event series require deriving a new evenly-spaced signal applicable to those methods. To avoid that requirement, in this study, the power spectrum of heart rate variability was estimated by Lomb-Scargle's algorithm, which is a means of obtaining PSD estimates directly from irregularly sampled timeseries observed in astronomy. To assess the performance of Lomb-Scargle algorithm in the power spectral analysis of heart rate variability, it was applied to various cardiac event series derived through integral pulse frequency modulation model(IPFM) simulation and from real ECG signals, and the resultant power spectra was compared with those obtained by a conventional method based on the FFT. In result, it is concluded that Lomb-Scargle's periodogram is very effective in the power spectral analysis of heart rate variability, especially in the presence of arrhythmia and/or dropouts of cardiac events.