• Journal of Institute of Control, Robotics and Systems
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• v.20 no.2
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• pp.126-131
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• 2014

This paper is concerned with a track management method for a naval combat system which receives the tracks information from multi-sensors and multi-tactical datalinks. Since the track management of processing the track information from diverse sources can be formulated as a data fusion problem, this paper will deal with the data fusion architecture, track association and track information determination algorithm for the track management of naval combat systems.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1822-1825
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• 2003

A practical range estimator based on the robust Kalman filter is proposed to solve the range estimation problem for surface to air missile(SAM) homing guidance. Apart from the previous works based on the extended Kalman filter(EKF) with bearing only measurement, the proposed scheme makes use of line-of-sight(LOS) rate to ensure the fast convergency at long-range. In this reason, the robust Kalman filter is considered to deal with LOS rate measurement error. The recursive linear structure of proposed filter is easy to implement and make it possible to reduce computational burdens. Moreover, it shows good estimation performance without specific guidance law such as oscillation proportional navigation guidance(OPNG).

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2230-2233
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• 1997

In this paper, the study on noise-seperator, which can seperate the modes of conducted noise, was conducted. The principle and analysis procedure of noise-seperator were studied. We presented the experiment, in which the noise problem was easily solved by seperating the modes from generated conducted noise of equipment using the fabricated noise-seperator.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.474-477
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• 2005

In tactical theater, it is crucial to detect ground moving targets and to locate them precisely. This problem can be resolved by using SAR (Synthetic Aperture Radar) sensors providing GMTI (Ground Moving Target Indication) capability. In general, to implement a robust GMTI sensor is not simple because of the strong competitions between target signals and clutter signals on the ground, and low speed of moving targets. Contrary to the case that a delay canceller is mostly suitable for ground surveillance radars, DPCA (Displaced Phase Centered Antenna) or STAP (Space Time Adaptive Processing) techniques have been adapted for GMT! function of modem airborne radars. In this paper, anew scheme of DPCA using two passive antennas with vertical separation is proposed, which also provides good clutter cancellation performance. The proposed scheme enables us to scan straight ahead of the carrying platform that is impossible with typical DPCA configuration. Simulations using various conditions have been performed to validate the proposed scheme, and the results are acceptable.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.658_659
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• 2009

This paper deals with the numerical implementation of the material sensitivity analysis, which is used to efficiently determine an optimal electric current distribution on a ship hull by corrosion of ship. A material sensitivity formula for the forward problem formulated in terms of the equivalent current method is analytically derived. Then, the components of the adjoint system including the electric pseudo-source are thoroughly investigated in order to obtain the first-order gradient information of an objective function with respect to the electric current. The purposed method has been successfully applied to a model ship and the predicted result on the underwater electric field due to corrosion of ship have been compared to that computed by FNREMUS software.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.757-766
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• 2017

For implementing the proportional navigation guidance law on passive homing missiles equipped with strapdown imaging infrared seekers, the line-of-sight angles and rates with respect to the inertial frame should be estimated by carefully handling the parasitic instability effect due to the seeker's latency. By introducing a new state vector representation along with the Pade approximation for compensating the time-delay of the seeker, this paper proposes a new guidance filter structure, stochastic dynamic models and measurement equations, in three-dimensional homing problem. Then, it derives the line-of-sight angle and rate estimator in general two-dimensional engagement by applying the extended Kalman filter to the proposed structure. The estimation performance and the characteristics of the proposed filter were evaluated via a series of numerical experiments.

• The Journal of the Acoustical Society of Korea
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• v.24 no.1E
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• pp.34-37
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• 2005

Ryu et al. proposed a multiple target angle-tracking algorithm without a data association problem using angular innovations. This algorithm, however, needs the computational loads in proportion to the square number of sensors regardless of the number of targets, because it uses a nonlinear equation between the signal subspace and angular innovation. In this Paper, we proposed an efficient algorithm for the multiple target angle-tracking using angular innovations. The proposed algorithm extracts the angular innovations from noise subspace. Also, it is demonstrated by computer simulations dealing with the tracking of crossing targets. The simulation results show that the computational loads of the proposed algorithm are $80\%$ and $60\%$ of those of Ryu's algorithm for 3 targets and 6 targets without degrading the performance of the target tracking.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.6
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• pp.816-821
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• 2015

In this paper, an in-flight prediction method of thrust profiles for solid rocket motors is proposed. Actually, it is very difficult to have detailed information about the performance of the rocket motors beforehand because it is quite sensitive to combustion environments. To overcome this problem, we have developed an algorithm for generating in-flight prediction of rocket motor performance in realistic environments via a reference burnback profile and accelerations measured at a short time-interval just after launch. The performance is evaluated through a lot of flight test results.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.2
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• pp.37-44
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• 2014

The most effective method to overcome GPS jamming problem is to use an adaptive array antenna which has the capability of beamforming or nulling to a certain direction. In this paper, Space Time Adaptive Processing (STAP) beamforming algorithm of four elements array antenna will be designed and the anti-jamming performance will be analyzed. According to the analysis, the signal to noise ratio (SNR) and anti-jamming performance can be enhanced by beamforming algorithm. Also, the time tap effect of STAP algorithm will be analyzed theoretically and verified with array antenna modeling and simulation. Specially, the cautious selection of reference time tap in STAP can prevent the degradation of position accuracy performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.585-590
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• 1997

Conventional foaming process has defects such as lower mechanical properties than ur~foaming material due to non-uniform cell distribution and environmental pollution problem caused by chemical blowing agency. So, a new foaming process such as Microcelluar plastics has been introduced to use inactive gases as a foaming agency. In order to apply Microcellular plastics for mass production process system such as extrusion, injection molding and blow molding, it needs to predict the change in material properties of polymer according to the amount of meltingas. In Polymer molding applying Microcelluar plastics, the change of viscosity among several material properties is the most important factor. Therefore, this paper is aimed to establish the method which not only finds out but also predicts the change of viscosity of ABS(Acrylonitri1e Butadiene Styrene) resin according to inert gas amount in extrusion molding.