• Journal of the Korean Society of Systems Engineering
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• v.6 no.1
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• pp.33-39
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• 2010

Anti-surface missiles have been the most dangerous threat to the surface ships, therefore analyzing the defense effectiveness of surface ships against diverse anti-surface missiles attack strategies is very important to evaluate and anticipate the naval combat ship's abilities in terms of AAW (Anti-Air Warfare). In this paper, we don't study on the defense effectiveness of a ship against a missile, but focus on the defense effectiveness for surface ships against multiple missiles specialized in strategies of anti-surface missiles; ripple fire attack and simultaneous time on target attack (STOT). So, we conduct a variety of monte-carlo simulations with high-fidelity simulators, analyze the measure of defense effectiveness for the key factors of strategies and evaluate the effects and possible interactions of several factors through the analysis of the design of experiment (DOE).

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.10
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• pp.817-824
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• 2017

This paper presents the characteristics of wing-tail interference for a tail-controlled missile. The magnitude of wing-tail interference was calculated with wind tunnel test results and its effects on aerodynamic coefficients were investigated. The downwash angle of tail wing was calculated with experimental data and the effect of wing-tail interference was expressed as a ratio of angle of attack. Numerical simulations were made to examine flow characteristics of wing-tail interference and the vorticity contour of missile were compared with respect to angle of attack. Experimental and numerical analysis results show that the wing-tail interference has significant effects on static stability of tail-controlled missile.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.9
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• pp.27-34
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• 2004

A computational study on the supersonic flow around the lateral jet controlled missile has been performed. For this purpose a three dimensional Navier-Stokes computer code(AADL3D) has been developed and case studies have been performed by comparing the normal force coefficient and the moment coefficient of a missile body for several parameters such as angles of attack, circumferential jet positions, and spouting jet angles. Missile surface is divided into four regions with respect to the center of gravity, and the normal force and moment distribution at each region are compared. The results show different behavior of the normal force and moment variation according to each parameter. Furthermore, it is shown that the pitching moment can be minimized through proper combination of each parameter.

• International Journal of Aeronautical and Space Sciences
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• v.11 no.2
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• pp.131-135
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• 2010

We report on the design of a three-axis missile autopilot using multi-objective control synthesis via linear matrix inequality techniques. This autopilot design guarantees $H_2/H_{\infty}$ performance criteria for a set of finite linear models. These models are linearized at different aerodynamic roll angle conditions over the flight envelope to capture uncertainties that occur in the high-angle-of-attack regime. Simulation results are presented for different aerodynamic roll angle variations and show that the performance of the controller is very satisfactory.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.4
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• pp.5-14
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• 2006

The correct and opportune decision of reengaging the intercepted target is required in order to enhance the engagement performance of the surface to air missile systems that has the ability to defense or attack against various targets at the same time. The engagement efficiency and success of these systems will be largely enhanced by assigning quickly its system resources to the intercepted target and minimizing the waste of system resources for the target which is not able to attack any more. The kill-assessment algorithm has to be able to evaluate automatically whether various targets intercepted by missiles are killed or not on the basis of the reasonable confidence level. The definition of kill assessment is discussed and the kill assessment algorithm is designed reliably by using Kalman filter and a probability theory. Finally its performance is evaluated and analyzed by the Monte Carlo simulation.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.448-455
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• 2014

Virtual Fire Control System(VFCS) in attack helicopter is developed. VFCS is comprised of multifunction display, store management computer, mission computer, target acquisition and designation system, mission planning system, weapon simulator and flight simulator. Weapon engagement process under the operational environment of helicopter was considered by using the VFCS. We considered hellfire missile, tow missile, unguided rocket and turret gun. The results of this study will be utilized efficiently on integrated fire control system SIL(System Integration Lab.) in attack helicopter.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.11
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• pp.901-907
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• 2021

The present study introduces an artificial neural network (ANN) that can predict the missile aerodynamic coefficients for various missile nose shapes and flow conditions such as Mach number and angle of attack. A semi-empirical missile aerodynamics code is utilized to generate a dataset comprised of the geometric description of the nose section of the missiles, flow conditions, and aerodynamic coefficients. Data normalization is performed during the data preprocessing step to improve the performance of the ANN. Dropout is used during the training phase to prevent overfitting. For the missile nose shape and flow conditions not included in the training dataset, the aerodynamic coefficients are predicted through ANN to verify the performance of the ANN. The result shows that not only the ANN predictions are very similar to the aerodynamic coefficients produced by the semi-empirical missile aerodynamics code, but also ANN can predict missile aerodynamic coefficients for the untrained nose section of the missile and flow conditions.

• Journal of the military operations research society of Korea
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• v.26 no.1
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• pp.34-46
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• 2000

The object of this study is to construct a model for an optimal allocation of short surface to air missile defending our targets most efficiently from hostile aircraft´s attack. For the purpose of this, we analyze and establish facility allocation concept of existing models, apply set covering theory appropriate to problem´s properties, present the process of calculating the probability of target being protected, apply Sherali-Kim´s branching variable selection strategy, and then construct the model. As constructed model apply the reducing problem with application, we confirm that we can apply the large scale, real problem.

• Journal of computational fluids engineering
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• v.11 no.3 s.34
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• pp.59-63
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• 2006

Accurate prediction of a supersonic missile base drag continues to defy even well-rounded CFD codes. In an effort to address the accuracy and predictability of the base drags, the influence of grid system and competitive turbulence models on the base drag is analyzed. Characteristics of some turbulence models is reviewed through incompressible turbulent flow over a flat plate, and performance for the base drag prediction of several turbulence models such as Baldwin-Loman(B-L), Spalart-Allmaras(S-A), k-$\varepsilon$, k-$\omega$ model is assessed. When compressibility correction is injected into the S-A model, prediction accuracy of the base drag is enhanced. The NSWC wind tunnel test data are utilized for comparison of CFD and semi-empirical codes on the accuracy of base drag predictability: they are about equal, but CFD tends to perform better. It is also found that, as angle of attack of a missile with control fins increases, even the best CFD analysis tool we have lacks the accuracy needed for the base drag prediction.

• Journal of electromagnetic engineering and science
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• v.18 no.4
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• pp.231-241
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• 2018

In this paper, we consider the anti-attack procedure of a ballistic missile defense system (BMDS) at different operating frequencies at its phased-array radar station. The interception performance is measured in terms of lateral divert (LD), which denotes the minimum acceleration amount available in an interceptor to compensate for prediction error for a successful intercept. Dependence of the frequency on estimation accuracy that leads directly to prediction error is taken into account, in terms of angular measurement noises. The estimation extraction is performed by means of an extended Kalman filter (EKF), considering two typical re-entry trajectories of a non-maneuvering ballistic missile (BM). The simulation results show better performance at higher frequency for both tracking and intercepting aspects.