• Journal of the Korean Society for Heat Treatment
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• v.5 no.2
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• pp.95-102
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• 1992

In this study, we tried to describe the quantitative model of TiN film structure which was deposited by PECVD process. The macro-grain growth behavior was studied at the various deposition pressures and times. As a result, It was confirmed that TiN films had the typical Zone 1 structure, and macro-columnar grains were, without reference to the deposition pressure, grown ballistic type by the growth-death competition following the equation, $Y=aX^2$, approximately obtained by regression analysis. Also, the thickness and the crystallization of TiN thin films were increased, the chlorine contents were decreased according to the decreasing of deposition pressure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.166-172
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• 1997

In order to find out relationship between hit probability and gun firing of a moving tank, a turret and flexible gun system model has been developed using the recursive flexible multibody dynamics. For a firing simulation model, nodal coordinates for a finite element model of a flexible gun have been employed to include traverse loads to the gun tube due to moving bullet and ballistic pressure. Modal coordinates are also used to represent the motion induced gun vibration before a firing occurs. An efficient switching technique from modal equations to nodal equations has been introduced for an entire gun firing simulation with rotating turret.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.301-306
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• 2008

A pyrogen igniter was designed to satisfy the required condition of kick motor system for the space launch vehicle. We analyzed the ignition characteristics and performed the combustion tests to verify the internal ballistic performance. In the design process, the arc-image test was carried out to find the sufficient heat flux as varying the initial pressure from 10 to 700kPa. The analysis indicated that the initial pressure condition would delay ignition time within a range from 100 to 500ms. The combustion test with an inert chamber was also performed to understand the ignition characteristics with the variation of the initial pressure of free chamber volume. Finally, we confirmed that the igniter could provide the acceptable energy to ignite the propellant of kick motor at the ground test. The result of the ground tests showed that the ignition delay time was within the design range at the atmospheric pressure condition.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.453-464
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• 2018

Purpose: The purpose of this study is to propose a solution to the case where $V_{50}$ calculation is impossible in the process of bulletproof test. Methods: In this study, we proposed a $V_{50}$ estimation method using logistic regression analysis. Six scenarios were applied by combining the homogeneity of the sample and the speed range. Then, 1,000 simulations were performed per scenario and six assumptions reflecting the reality were applied. Results: The result of the study, it was confirmed that there was no statistical difference between the $V_{50}$ value calculated by the conventional method and the $V_{50}$ value calculated by the improvement method. Therefore, in situations where $V_{50}$ can not be calculated, it is reasonable to use logistic regression analysis. Conclusion: This study develops a methodology that is easy to use and reliable by using statistical model based on actual data.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.2
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• pp.283-295
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• 2010

Although some large units, upper than division, have a identification system, most of them depend on US military. Especially, the company unit can not but execute GOP(General OutPost) guidance and battles inefficiently because they apply the method of conventional identification system. urrently, North Korea causes the high tension of peninsular by experimenting nuclear weapons and launching ICBM(Intercontinental Ballistic Missile). In addition, ROK military will reduce the number of personnel and division through reorganizing the structure into NCW (Network Centric Warfare) until 2020. These unstable situation and future tendency require the high technical identification system based on USN(Ubiquitous Sensor Network) in company unit level. his study suggests the method that the company unit apply the identification system based on USN which distinguish between friend and foe in the warfare. The identification system concludes the results through experiment of military analysis model (AWAM; Army Weapon effectiveness Analysis Model). After analyzing the experiment results, it indicates the budget requirement and operational operability of identification system. This will be able to improves battle efficiency and to prevent damages of friendly forces.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.668-671
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• 2010

Comparative study on propellant modeling has been investigated using a non-dimensional method and an one-dimensional method. The propellant location in the chamber can not be described by the non-dimensional method. It is, however, possible for the one-dimensional method to describe. Therefore, the analysis of the interior ballistics according to the propellant arrangements has been performed by the one-dimensional method. The negative differential pressure in the chamber could be predicted and the necessity of the one-dimensional modeling for the analysis of the interior ballistics has been confirmed.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.35-48
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• 2018

The study of air defense against North Korean tactical ballistic missiles (TBM) should consider the rapidly changing battlefield environment. The study for target re-designation for intercept missiles enables effective operation of friendly defensive assets as well as responses to dynamic battlefield. The researches that have been conducted so far do not represent real-time dynamic battlefield situation because the hit probability for the TBM, which plays an important role in the decision making process, is fixed. Therefore, this study proposes a target re-designation algorithm that makes decision based on hit probability which considers real-time field environment. The proposed method contains a trajectory prediction model that predicts the expected trajectory of the TBM from the current position and velocity information by using random forest and moving window. The predicted hit probability can be calculated through the trajectory prediction model and the simulator of the intercept missile, and the calculated hit probability becomes the decision criterion of the target re-designation algorithm for the missile. In the experiment, the validity of the methodology used in the TBM trajectory prediction model was verified and the superiority of using the hit probability through the proposed model in the target re-designation decision making process was validated.

• Journal of the Korea Institute of Building Construction
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• v.20 no.1
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• pp.43-51
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• 2020

The main purpose of protective facility for small military unit is to provide the protection of not all the weapons system but the near-miss bullet in Korean army. In particular about the small caliber bullets, especially KM80 in Korea, there were many studies that both of the experiential and structural design methods dose not reflect enough the military threat. For that reason, a new equation to calculate effective anti-piercing depths for RC slabs against small caliber bullets is proposed in earlier research with actual shooting test. But, the test only considers the strength of concrete without the thickness of concrete, types of aggregate, the angle of yaw of bullet, high-strength concrete, etc. Therefore, this study evaluated the ballistic resistance performance by thickness and proportion of magnetic aggregate of concrete. As a result, we identified two major statistical estimations that the error of piercing depth by the angle of yaw of bullet could be cancelled by barrage and the thickness and proportion of magnetic aggregate of concrete dose not effect on the protection ability of concrete structure.

• Journal of Aerospace System Engineering
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• v.16 no.1
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• pp.56-69
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• 2022

Various advanced countries are accelerating the competition in the development of hypersonic weapons. North Korea is on the verge of building a new submarine equipped with a submarine-launched ballistic missile (SLBM). A series of new guided missiles tests have continued due to political competition between the U.S. and China. The Republic of Korea is planning to boost its military capabilities, which involves the development of nuclear-powered submarines, light aircraft carriers, and new guided missiles. The northeast Asian region continues to be tense amid military rivalry between the Republic of Korea, North Korea, the United States, China, Russia, and Japan. Accordingly, these countries' competition to develop weapons is also at the world's highest level. In this paper, we examine the functioning of a hypersonic weapons system conduct a technical analysis of its components. In addition, we analyze the direction of military development that the Korean military wants to pursue through the recently announced mid-term defense plan. We conclude by highlighting the technical limitations and implementation strategies to overcome the development of hypersonic weapons.

• Journal of Ocean Engineering and Technology
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• v.33 no.6
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• pp.535-546
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• 2019

The paper presents a closed-form analytical solution for the ultimate strength of sandwich panels with metal faces and an elastic isotropic core during combined in-plane compression and lateral pressure under clamped boundary condition. By using the principle of minimum potential energy, the stress distribution in the faces during uni-axial edge compression and constant lateral pressure was obtained. Then, the ultimate edge compression was derived on the basis that collapse occurs when yield has spread from the mid-length of the sides of the face plates to the center of the convex face plates. The results were validated by nonlinear finite element analysis. Because the solution is analytical and closed-form, it is rapid and efficient and is well-suited for use in practical structural design methods, including repetitive use in structural optimization. The solution applies for any elastic isotropic core material, but the application that stimulated this study was an elastomer-cored steel sandwich panel that had excellent energy absorbing and protective properties against fire, collisions, ballistic projectiles, and explosions.