• Journal of Convergence for Information Technology
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• v.9 no.6
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• pp.91-96
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• 2019

Recently, it is expected for requirement for more scientific research of weapon systems acquisition alternatives with reliability and objectivity. For these needs, study on methodology of weapon systems acquisition alternatives is but on-going, but it is still in its early stages and is unprofessional. We compared general decision making methods, government development program decision making methods, methodologies of weapon systems acquisition alternatives research such as AHP, ANP, KAAM and proposed AHP as weapon acquisition analysis. This study guarantees objectivity and derives scientific research results reliability by analyzing and comparing comprehensive elements such as cost, effectiveness, deployment schedule, program management risk. Further study on AHP weight and other decision making methods is needed considering category of weapon systems and program characteristics.

• Journal of the Korea Society for Simulation
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• v.28 no.1
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• pp.41-47
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• 2019

Defense simulation is actively used to test various weapon systems and evaluate their effectiveness. The AddSIM environment is a simulation framework designed to support the weapon systems dealt with in defense simulation from an integrated point of view and is designed for reuse and scalability. Models used in AddSIM require base model structure fidelity and verification of user code area. Therefore, this paper describes the dynamic verification method used for completeness of models used in AddSIM. For the dynamic verification of user code, the specification method and the verification algorithm are described. Also, we introduce the prototype of the dynamic verifier implemented based on verification specification method and algorithm. The case study analyzes the verification results based on the simulation example implemented in AddSIM environment.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.133-143
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• 2021

In government procurement programs, cost estimation and analysis support funding decisions and are the basis for other major decisions, too. Such estimating and analyzing the cost of the weapon systems are crucial in execution of the defense budget. However, existing cost estimations and analyses have focused on domestic R&D projects, thus those are not valid in application to foreign weapon acquisitions. This study aims at foreign weapon systems that are acquired from Direct Commercial Sales. Because the data for price estimation of a foreign weapon is usually not available, we suggest a price estimation model based on performance factors of the weapon. In this study, the proper price of the weapon system is estimated using the parametric cost estimating model. Using the data of helicopter-launched anti-tank guided missiles worldwide, we analyze the effect of each performance factor on the weapon system price by regression analysis, and use step-wise and ridge regression analysis to remove multi-collinearity. This study hopefully contributes to more reasonable decision making on proper price of weapons.

• International Journal of Computer Science & Network Security
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• v.22 no.6
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• pp.390-399
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• 2022

Cyber security and resilience are phrases that describe safeguards of ICTs (information and communication technologies) from cyber-attacks or mitigations of cyber event impacts. The sole purpose of Risk models are detections, analyses, and handling by considering all relevant perceptions of risks. The current research effort has resulted in the development of a new paradigm for safeguarding services offered online which can be utilized by both service providers and users. customers. However, rather of relying on detailed studies, this approach emphasizes task selection and execution that leads to successful risk treatment outcomes. Modelling intelligent CSGs (Cyber Security Games) using MLTs (machine learning techniques) was the focus of this research. By limiting mission risk, CSGs maximize ability of systems to operate unhindered in cyber environments. The suggested framework's main components are the Threat and Risk models. These models are tailored to meet the special characteristics of online services as well as the cyberspace environment. A risk management procedure is included in the framework. Risk scores are computed by combining probabilities of successful attacks with findings of impact models that predict cyber catastrophe consequences. To assess successful attacks, models emulating defense against threats can be used in topologies. CSGs consider widespread interconnectivity of cyber systems which forces defending all multi-step attack paths. In contrast, attackers just need one of the paths to succeed. CSGs are game-theoretic methods for identifying defense measures and reducing risks for systems and probe for maximum cyber risks using game formulations (MiniMax). To detect the impacts, the attacker player creates an attack tree for each state of the game using a modified Extreme Gradient Boosting Decision Tree (that sees numerous compromises ahead). Based on the findings, the proposed model has a high level of security for the web sources used in the experiment.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.1
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• pp.9-22
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• 2022

A fighter performing a reconnaissance mission is equipped with a pod that drives optical/infrared sensors for acquiring and identifying target information on the lower part of the fuselage. Due to the nature of the reconnaissance mission, the fighter performs high speed evasive maneuvers, and the resulting load should be considered importantly for the development of the pod. This paper concerns a numerical investigation into the inertial and aerodynamic loads of the airborne pod of high performance aircrafts. For the aerodynamic load analysis, the pylon and pod shapes are added to the fighter 3D model, and the commercial software was used for static and dynamic analysis. Considering the practical mission conditions, the common/extreme conditions were established respectively in the static and dynamic situations of pods and the driving torque could be tripled under dynamic conditions. In the analysis of inertia load, a 3-DOF model considering roll and turning maneuvers was derived by the Lagrangian method, and then the numerical integration method was applied to the analysis. As a results, it was conformed that the inertia load was generally induced at a low level compared to the aerodynamic load, but depending on the unbalance mass condition of the pod, the inertia load cannot be negligible.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.18-27
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• 2023

In this paper, the structural-thermal-optical performance analysis of the mirror was performed by setting the laser heat source as the boundary condition of the thermal analysis. For the laser heat source model, the Beer-Lambert model considering semi-transparent optical material based on Gaussian beam was selected as the boundary condition, and the mechanical part was not considered, to analyze the performance of only the mirror. As a result of the thermal analysis, thermal stress and thermal deformation data due to temperature change on the surface of the mirror were obtained. The displacement data of the surface due to thermal deformation was fitted to a Zernike polynomial to calculate the optical performance, through which the performance of the mirror when a high-energy laser was incident on the mirror could be predicted.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.19-28
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• 2024

This paper proposes a method to improve the performance of ship identification through lofargram analysis of ship noise by applying the Hough Transform to a Convolutional Neural Network (CNN) model. When processing the signals received by a passive sonar, the time-frequency domain representation known as lofargram is generated. The machinery noise radiated by ships appears as tonal signals on the lofargram, and the class of the ship can be specified by analyzing it. However, analyzing lofargram is a specialized and time-consuming task performed by well-trained analysts. Additionally, the analysis for target identification is very challenging because the lofargram also displays various background noises due to the characteristics of the underwater environment. To address this issue, the Hough Transform is applied to the lofargram to add lines, thereby emphasizing the tonal signals. As a result of identification using CNN models on both the original lofargrams and the lofargrams with Hough transform, it is shown that the application of the Hough transform improves lofargram identification performance, as indicated by increased accuracy and macro F1 scores for three different CNN models.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.5
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• pp.544-557
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• 2024

This paper theoretically analyzes the effect of the velocity and attitude errors of Master Inertial Navigation System(MINS) on the accuracy of Slave Inertial Navigation System(SINS) transfer alignment in velocity and attitude matching, and validates the analysis through simulation. Theoretical analysis involves deriving a new state equation that considers the velocity and attitude errors of MINS from the state equation of the transfer alignment filter, and deriving the state estimation equation of the Kalman filter based on this. The analysis confirms that MINS's velocity and attitude errors induce the same level of velocity and attitude errors in SINS. A reference inertial navigation system model is added to the simulation model, and the transfer alignment accuracy is analyzed by comparing the navigation information of MINS and SINS with the reference inertial navigation system. It is confirmed that the accuracy analysis results through simulation are consistent with the theoretically analyzed results, and through this, the validity of the theoretically analysis in this paper is verified. The research findings indicate that when performing transfer alignment using MINS, which is likely to be operated for prolonged periods in pure inertial navigation mode, the navigation errors of MINS are transferred to SINS. This implies that initial correction navigation is necessary to be considered for SINS

• Journal of Advanced Navigation Technology
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• v.28 no.5
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• pp.650-656
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• 2024

This study proposes an AI-based image restoration technique to reduce image distortion caused by lighting and noise in nighttime environments and improve the performance of infrared detection systems. A synthetic image dataset was constructed using visible light images under various lighting conditions and ISO settings, and deep learning models (AutoEncoder and U-Net) were trained to assess image restoration performance. Experimental results show that the Multi-ISO model (9-channel) outperforms the Single-ISO model (3-channel), especially when utilizing input data with multiple ISO values. This study demonstrates that AI models can be effectively trained using synthetic data, even when real data collection is challenging, and can be applied to image restoration tasks. These findings are expected to contribute to enhancing the performance of optical detection systems through AI-based technology.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.348-356
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• 2014

The existing effective path-length model of ITU-R has some drawbacks: The prediction error is quite large compared to domestic measurement data and it is an empirical model in which the physical characteristics of rain cells are not considered. In this paper, a theoretical model for effective path-length using the rain-cell concept was proposed and its validity was verified using the measurement data. To analyze the statistical characteristics of rain cell parameters, the weather-radar data(CAPPI) measured by Korea Meterological Administration were analyzed and the correction factor was properly introduced to fit the Chollian beacon measurement data of ETRI(Electronics and Telecommunications Research Institute). To verify the proposed effective path-length model, it was compared with the Mugunghwa No. 5 beacon data measured in Chungnam National University with the support of ADD(Agency for Defense Development). It was confirmed that the prediction results of the proposed model are in good agreement with the measurement data.