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Suk Chan KIM Iickho SONG Seokho YOON So Ryoung PARK
If the direction of arrival (DOA) of a source is perturbed due to some reasons in a statistical way as in the environment of wireless mobile communications, a new model appropriate for such environment should be used instead of the point source model. In this paper, an angle-perturbed source model is proposed and an estimation method based on the eigen-decomposition technique is investigated under the model. The asymptotic distribution of the estimation errors is obtained to see the statistical properties.
Seong Ill PARK So Ryoung PARK Iickho SONG Jooshik LEE Young-Sup JOO Dae Jin KIM
In this paper, we investigate an inherent noise reduction characteristic of a modulated orthogonal sequence. The modulated orthogonal sequence generates length N2 sequences from N information symbols. Using the amplitudes of received sequences, we first estimate the smallest amplitude noise. Then the noise is reduced by the proposed scheme. The noise reduction scheme is shown to have an excellent performance in non-Gaussian noise environment.
Taeung YOON Youngpo LEE So Ryoung PARK Suk Chan KIM Iickho SONG Seokho YOON
The relationship between the degree of overlap in direct modulation chirp spread spectrum systems with binary phase shift keying and intersymbol interference (ISI) is analyzed. It is observed that the ISI due to overlap fluctuates or monotonically increases as the number of overlaps changes and that, in some cases, the overlap does not incur ISI at all.
This paper investigates the autonomous decision-making process of the selection of alternative countermeasures against threats in electronic warfare settings. We introduce a threat model, which represents a specific threat pattern, and a methodology that decides the best countermeasure against real-time threats using the decision theory. To determine the optimal countermeasure, we model the probabilities of the effects of countermeasures, if executed, and combine the probabilities with their utilities. This methodology based upon the inductive threat model calculates the expected utilities of countermeasures which are applicable given a situation, and provide an intelligent command and control agent with the best countermeasure to threats. We present empirical results that demonstrate the agent's capabilities of choosing countermeasures to threats in simulated electronic warfare settings.
So Ryoung PARK Iickho SONG Seokho YOON
A unified decision scheme for the classification and localization of cable faults is proposed based on a two-step procedure. Having basis in the time domain reflectometry (TDR), the proposed scheme is capable of determining not only the locations but also types of faults in a cable without an excessive additional computational burden compared to other TDR-based schemes. Results from simulation and experiments with measured real data demonstrate that the proposed scheme exhibits a higher rate of correct decision than the conventional schemes in localizing and classifying faults over a wide range of the location of faults.