• Journal of Sensor Science and Technology
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• v.22 no.1
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• pp.44-48
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• 2013

For a successful commercialization of microbolometer, it is required to develop a robust package including thermal stabilizing mechanism. In order to regulate the temperature within some operating range, thermoelectric cooler is generally used but it's not easy to model the whole package due to the coupled physics nature of thermoelectric cooler. In this paper, SPICE-compatible modeling methodology of a microbolometer package is presented, whose steady-state results matched well with FEM results at the maximum difference of 5.95%. Although the time constant difference was considerable as 15.7%, it can be offset by the quite short simulation time compared to FEM simulation. The developed model was also proven to be useful for designing the thermal stabilizer through parametric and transient analyses under the various working conditions.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.11
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• pp.944-952
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• 2001

Inertial navigation system(INS) errors increase with time due to inertial sensor errors, and therefore it is desired to combine INS with external aids such as GPS. However GPS informations have a randomly abrupt jump due to a sudden corruption of the received satellite signals and environment, and moreover GPS can\`t provide navigation solutions. In this paper, smoothing and prediction schemes are proposed for GPS`s jump or unavailable GPS. The smoothing algorithm which is designed as a scalar adaptive filter, smooths abrupt jump. The prediction algorithm which is proved by Schuler error model of INS, estimates INS error in appropriate time. The outputs of proposed algorithm apply stable measurements to GPS aided INS Kalman filter. Simulations show that the proposed algorithm can effectively remove measurement jump and predict INS error.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.181-185
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• 2004

In these days, many reports noticed that the Internet worms spread out and have done considerable damage to all over the world network within a few days. The worms, which is infected from various route such as e-mail, can spread very fast with common property, self replication. But, there is not prepare for the way effectively to interrupt internet worm. Therefore, to prevent our network resource, internet hosts and user clients, the systemic categorization and automatic defense mechanism is required in the Internet worm research. Hence, in this paper, we describe internet worm propagation and defense model.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.5
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• pp.49-57
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• 2008

In this paper, we suggested a methodology that can be used by an agent to learn models of other agents in a multi-agent system. To construct these model, we used influence diagram as a modeling tool. We present a method for learning models of the other agents at the decision nodes, value nodes, and chance nodes in influence diagram. We concentrated on learning of the other agents at the value node by using neural network learning technique. Furthermore, we treated anti-air units in anti-air defense domain as agents in multi. agent system.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.1
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• pp.29-36
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• 2014

In this paper, a novel MBE (Model Based target size Estimator) is presented for SDIIR (Strap Down Imaging Infrared) seekers. The target tracking requires the target size information for which residual range between target and missile should be provided. Unfortunately, in general, the missile with passive sensor such as IIR (Imaging Infrared), CCD (Coupled Charging Device) cannot obtain range information. To overcome the problem, the proposed method enables the SDIIR seeker to estimates target size by using target size model and track the target. The performance of proposed method is tested at IIR target tracking of target intercept scenario. The experiment results show that the proposed algorithm has the relatively good performance.

• Structural Engineering and Mechanics
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• v.42 no.3
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• pp.363-381
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• 2012

This study is aimed at providing an efficient analytical model to obtain pressure- impulse diagram of one-way reinforced concrete slabs subjected to different shapes of air blast loading using single degree of freedom method (SDOF). A tri-linear elastic perfectly plastic SDOF model has been used to obtain the pressure-impulse diagram to correlate the blast pressure and the corresponding concrete flexural damage. In order to capture the response history for the slab, a new approximately SDOF method based on the conventional SDOF method is proposed and validated using published test data. The influences of pulse loading shape on the pressure-impulse diagram are studied. Based on the results, a pressure-impulse diagram generation method using SDOF and an analytical equation for the pressure-impulse diagram is proposed to different damage levels and different blast loading shapes.

• Journal of Magnetics
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• v.20 no.1
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• pp.62-68
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• 2015

This paper presents an experimental technique to accurately separate a permanent magnetic field and an induced one from the total magnetic fields generated by a steel ship, through compensating for the Earth's magnetic field. To achieve this, an Earth's magnetic field simulator was constructed at a non-magnetic laboratory, and the field separation technique was developed, which consisted of five stages. The proposed method was tested with a scaled model ship, and its permanent and induced magnetic fields were successfully extracted from the magnetic field created by the ship. Finally, based on the separated permanent magnetic field data, the permanent magnetization distribution on the hull was predicted by solving an inverse problem. Accordingly, the permanent magnetic fields generated by the ship can easily be calculated at any depth of water.

• The Journal of the Acoustical Society of Korea
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• v.40 no.2
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• pp.99-108
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• 2021

In this paper numerical wave propagation experiments have been performed to visually confirm whether the signals scattered by water masses can be a false alarm in active sonar. The numerical environments consist of exaggerated water masses as targets in free space. Using a pseudospectral time-domain model for irregular boundary, the back-scattered signals have been calculated and compared with analytic solutions. Also, the sound propagation was simulated. Consequently, it was verified that water masses themselves could not be detected as a false target.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.4
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• pp.344-351
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• 2023

Static ejection tests were conducted using the 2,000lb-Class Store to provide ejector model for the store separation simulation. In this study, static ejection test device for 2,000lb-class store was constructed and reaction force applied to store was measured over time. In addition, the trajectories of the ejected store were obtained using photogrammetry and compared with the simulations using developed ejector model. The results of the static ejection test were analyzed to determine the cartridge-orifice combination to be used for store separation. Flight tests were performed by applying the analysis results and verified that the store was safely separated from the aircraft.

• Convergence Security Journal
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• v.15 no.6_1
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• pp.69-78
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• 2015

Methods that industrial spies use to smuggle core technology out are becoming more intelligent, technological, and complex, thus resulting in more serious damages. In particular, defense industries in which involve national core technology as well as institutions including labor force are industries that are in a greater need of the convergence security. Defense Industry develops, experiments, and produces defense security supplies for national security protection. Defense industry involves a number of security elements such as military secret, industrial secret, core technology labor force, defense industry supply, critical national facility, and information communication system. Defense industry security is a complex of military security and industrial security which is convergence security that integrates all security elements of defense industry. Therefore, defense industry security is a typical ideal model for convergence security. Research on defense industry security is relatively insufficient compared to research of security in other industrial fields. In order to prevent core technology of denfese industry from leaking and to protect technical professionals and institutions, research and action on defense industry security from convergence security perspective are therefore essential at this point of time.