• International Journal of Ocean System Engineering
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• v.3 no.3
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• pp.158-163
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• 2013

The acoustic target strength (TS) is one of the most important parameters for a submarine's stealth design. Because modem submarines are larger than their predecessors, TS must be managed at each design stage in order to reduce it. To predict the TS of a submarine, TASTRAN R1 was developed based on a Kirchhoff approximation in a high-frequency range. This program can present TS values that include multi-bounce effect in the exterior and interior of the structure by combining geometric optics (GO) and physical optics (PO) methods, anechoic coating effect by using the reflection coefficient, and response time pattern for a detected target. In this paper, TS calculations for a submarine model with the above effects are simulated by using this developed program, and the TS results are discussed.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.90-96
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• 2018

This study investigated the manufacturing process and characteristics of $BKNO_3$ (Boron Potassium Nitrate) as a pyrotechnic propellant that is commonly used in the aerospace, defense, and automobile industries. The solid mixture was composed of oxidizing agent, fuel, and binder. Evaporation process was used to uniformly mix the raw materials. The optimal ratio of composition was designed through the CEA program analysis of the material characteristics and thermal responses. Further the size, shape, sensitivity, and calorimetry characteristics were studied.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.2
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• pp.1-9
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• 2023

The purpose of this study is to derive the need to improve the test and evaluation(T&E) performance system of the weapon systems to which advanced science and technology is applied, evaluate priorities, and present development plans. T&E of Al-based weapon systems through a literature research and case analysis on changes in the T&E environment for weapon system, 11 detailed evaluation items were derived from the in terms of the T&E system, structure, and technology. Al-based weapon system test evaluation should be performed in parallel with data-based performance evaluation and actual T&E, and performance measurement using a separate T&E data set is required for AI models performance evaluation. As a result of analyzing the importance of T&E through AHP analysis, the order of T&E system-technology-structure was evaluated, and the priority of detailed evaluation items was evaluated in the order of T&E result judgment-T&E organization and expert training-scientific T&E. For evaluation items with high priority, measures to improve the T&E performance system were presented.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.89-100
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• 2018

The precedent study stage of defense programs is a project stage that is conducted to support the determination of an efficient acquisition method of the weapon system determined by the requirement. In this study, the FTA/FMEA technique was used in the safety analysis process to identify elements to be conducted in the precedent study stage and a methodology for deriving the key review elements through conceptualization and tailoring was suggested. To supplement the key elements derived from the existing research, it is necessary to analyze various events that may arise from key elements. To accomplish this, the HAZOP technique for safety analysis in other industrial fields was used to supplement the results of kdy element derivation. We analyzed and modeled the execution procedure by establishing input/output information and association with the key elements of the precedent study stage derived by linking HAZOP/FTA/FMEA techniques. In addition, performance maturity was evaluated for performance of precedent study, and a risk-based response manual was generated based on inter-working information with key elements with low maturity. Based on the results of this study, it is possible to meet the performance, cost, and schedule of the project implementation through application of the key elements and procedures and the risk management response manual in the precedent study stage of the defense program.

• Korean Journal of Computational Design and Engineering
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• v.22 no.2
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• pp.141-149
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• 2017

Vulnerability assesses the loss of major performance functions of GCV (Ground Combat Vehicles) when it is hit by enemy's shell. To decide the loss of major functions, it is determined what effects are on the performance of GCV when some components of GCV are failed. M&S (Modeling and Simulation) technology is used to vulnerability assessment. The hydro-pneumatic suspension is used as a sample part. The procedures of vulnerability assessment of the hydro-pneumatic suspension are shown as follows: 1) The components of the suspension are defined, and shot lines are generated evenly around the part. 2) The penetrated components are checked by using the penetration equation. 3) The function model of the suspension is designed by using IDEF0. 4) When the failure of the critical components of the suspension happens, its effect on the function of the suspension can be estimated using DMEA (Damage Mode and Effects Analysis). 5) The diagram of FTA (Fault Tree Analysis) is designed by exploiting DMEA. 6) The damage probability of the suspension is calculated by using FTA and vulnerable area method. In this paper, SLAP (Shot Line Analysis Program) which was developed based on COVART methodology. SLAP calculates the damage probability and visualizes the vulnerable areas of the suspension.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.78-84
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• 2020

The performance of pintle thruster is analyzed by using the pintle thruster performance analysis model which integrating the element models introduced in Part I. To verify the performance analysis, the results of the developed program are compared with the experimental data of kerosene/hydrogen peroxide liquid pintle thrusters. Based on the results, the characteristics of the pintle thruster are analyzed. The sensitivity analysis is performed to investigate the effect of thruster shape and operation parameters on performance characteristics using both OAT and scatter plot methods. The four performance parameters such as droplet diameter, film flow rate, O/F ratio, and nozzle throat diameter are evaluated to investigate their effects on characteristic speed, combustor pressure, and specific thrust.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.441-444
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• 2016

Peace on the Korean Peninsula is threatened by physical aggressions and cyber terrors such as nuclear tests, missile launchings, senior government officials' smart phone hackings and DDos attacks to banking systems. Cyber attacks such as vulnerability for the hackings, malware distributions are generally defended by passive defense through the detecting signs of first invasion and attack, data analysis, adding library and updating vaccine programs. In this paper the concept of security program based on Google TensorFlow machine learning ability to perform adding libraries and solving security vulnerabilities by itself is researched and proposed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1623-1631
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• 2016

There are many researches which analyze vulnerability for combat systems, have been progressing, and apply the analyzed result to reflect on design phase. Recently, there have been requirements for integrating the previous module based researches which conducted independently. In this paper, we propose an integrated vulnerability analysis method for the combat system considering characteristics of threats and protection performance of armors through an analysis of the advanced research. In addition, by applying the proposed method improves the existing hit probability analysis program and we are verified based on scenarios for improving survivability of PKM (Petrol Killer Medium) for vulnerability analysis confirmed the results. The proposed method improves reliability of vulnerability analysis by considering threats and defense ability. Also it able to satisfied with the integration requirements. Furthermore, we became buildup for the development of applied system and the method and integrated vulnerability analysis method for combat systems.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.10
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• pp.797-804
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• 2016

The vehicle-mounted radar system (VMRS) including its electronic parts must be designed so that its performance is maintained under varying environmental conditions. The important aspects are typically weight and safety. Since many rotating VMRSs have been developed, discussion about the vibration and shock requirements for the transportation conditions has occurred: in addition, the dynamic unpaved, paved, and off-road effects have been emphasized with respect to lightweight designs. A lightweight-design VMRS should be capable of operating stably under the wind condition with the support of the vehicle structure. In this paper, a structural analysis regarding the support of the VMRS is performed, whereby the real-load conditions for three types of road and pressure were employed in terms of the wind condition. The structural analysis for the safety of the VMRS is performed, and the structural-integrity analytical processes of the VMRS are presented for different load conditions.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.1
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• pp.124-132
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• 2018

This paper presents a shelf life assessment for K-1 military gas masks in the Republic of Korea using test data of Chemical Materiels Stockpile Reliability Program(CSRP). For the shelf life assessment, over 2,500 samples between 2006 and 2015 were collected from field tests and analyzed to estimate a probability of proper and improper functionality using Bayesian estimation. For this, three stages were considered; a pre-processing, a processing and an assessment. In the pre-processing, major components which directly influence the shelf life of the mask were statistically analyzed and selected by applying principal component analysis from all test components. In the processing, with the major components chosen in the previous stage, both proper and improper probability of gas masks were computed by applying Bayesian estimation. In the assessment, the probability model of the mask shelf life was analyzed with respect to storage periods between 0 and 29 years resulting in between 66.1 % and 100 % performances in accuracy, sensitivity, positive predictive value, and negative predictive value.