• Honam Mathematical Journal
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• v.44 no.4
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• pp.572-593
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• 2022

Crime committed by civilians and criminals using legal and illegal firearms and conversion of legal firearms into illegal ones has become a common practice around the world. As a result, policies to control civilian gun ownership have been debated in several countries. The issue arose because the linkages between firearm-related mortality, weapon accessibility, and violent crime data can imply diverse options for addressing criminality. In this paper, we have projected a mathematical model in terms of the Caputo fractional derivative to address the issues viz. input of legal guns, crime committed by legal and illegal guns, and strict government policies to monitor the license of legal guns, strict action against violent crime. The boundedness, existence and uniqueness of solutions and the stability of points of equilibrium are examined. It is observed that violent crime increases with the increase of crime committed by illegal guns, crime committed by legal guns and, decreases with the increase of legal guns, the deterrent effect of civilian gun ownership, and action of law against crime. Further, legal guns increase with the increase of the limitation of trade of illegal guns and decrease with the increase of conversion of legal guns into illegal guns and increase of the growth rate of illegal guns. Again, as crime is committed by legal guns also, the policy of illegal gun control does not assure a crime-free society. Weak gun control can lead to a society with less crime. Theoretical aspects are numerically verified in the present work.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.179-187
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• 2021

Army guns, swords, and explosives are substances that remain in danger and are expected to suffer significant damage in the event of an accident. Therefore, considerable attention is needed to handle them. Safety management of army guns, swords, and explosives can be classified into manufacturing, storage, and transportation, among which transportation is essential for performance tests and contract delivery. In 2020, the number of army guns, swords, and explosives transport increased by 30% compared to 2014, which can be seen as an increase in the demand for the transportation of army guns, swords, and explosives by defense companies due to defense improvement projects. Meanwhile, social interest in explosives safety management and social demands for strengthening safety management are increasing due to the explosions of explosive plants. Therefore, it is necessary to look at the status of safety management. This study examined the safety management for the transportation of army guns, swords, and explosives in the united states and domestic private sector. This paper presents improvements to safely and efficiently transport army guns, swords, and explosives.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.807-812
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• 2023

This study examines the training effectiveness of airsoft guns that look and operate like real guns. Airsoft guns were developed in Japan in the late 1970s and are now popular for leisure sports and training, especially in countries where gun ownership is permitted. In particular, Taiwan has been promoting airsoft gun games to train citizen soldiers, and military leaders such as the United States have also utilized airsoft guns for live fire combat training and combat troops' live fire training. However, due to strict usage regulations and the perception that it is a toy, it is underutilized in Korea despite being a good training tool. Therefore, this study will prove the effectiveness of airsoft guns and improve the military's combat capabilities through practical training using airsoft guns. In addition, it will improve the negative perception of airsoft guns and foster a new sports industry.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.117-119
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• 1994

While the projectile in the induction type coil guns is in motion, there exists an induced current in the sleeve coils of the projectile. The motion includes not only the z-axial movement but transversal movement. The projectile in coil guns, which is not supported physically, gets a force in the transversal axis to have a motion in this axis. As a result of this motion, sleeve effects are exhibited to the projectile. This paper presents the analysis of the secondary effect especially due to the propelling velocity of the projectile.

• Journal of the military operations research society of Korea
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• v.8 no.2
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• pp.17-30
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• 1982

This paper offers an optimal artillery deployment scheme for the defending unit when two forces are confronted at a military front line. When proposed gun sites, types and number of guns as well as targets are given, the solutions of the two models in this paper direct each (unit of) guns to a certain location. The aim of the models is to maximize the number of guns which can hit important targets. Unlike widely used target assignment models, these models are formulated using the set covering problem concept. These models do not contain probabilities and time. Thus they are simple as models, easy in implementation, and yield tractable solutions. The dynamic and probabilistic feature of battle situations is implicitly reflected on the models. The first model is for the case that enemies' approaching route is clearly predictable, while the second model is for the unpredictable approaching route case.

• Electronics and Telecommunications Trends
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• v.37 no.1
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• pp.10-20
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• 2022

A drone without attaching guns or bombs can be a dangerous weapon, since its motor speed is greater than 3000 rpm, which is similar to that of a mower powered by a LiPo battery. The anti-drone system is the only means of detecting and neutralizing drone attacks. Many defense companies around the world provide solutions using various types of equipment (for example, radar, cameras, jamming guns, and net guns). ETRI has also developed a Low-Altitude Drone Detection (LADD) system consisting of Ku-band radar and an Electro-Optical/Infra-Red (EO/IR) camera. In this paper, we summarize recent technical advances in anti-drone systems around the world and introduce the features and describe the performance of the LADD system.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.599-602
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• 1999

In this paper, we attempt to control the pressure between two specimens using a servo gun in the resistance spot welding process. Servo guns have some advantages over pneumatic guns in that the fast response, the precise position control, and the accurate torque control are assured by virtue of the servo motor control. To demonstrate the practical significance of our results, we present some experimental results..

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.8
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• pp.1057-1067
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• 2010

Vibration and noise analysis as well as strength of gear teeth, gear profile design are considered in order to develop the multi-gear train devices of synchro system for the guns of a warship. A new approach to the critical speed calculation of practical industrial multi-mesh geared system is presented. A transfer matrix model based on Hibner's branch method is developed and the natural properties of the branched rotor system are calculated with using the ${\lambda}$-matrix formulation. A Campbell diagram, in which the excitation sources caused by the mass unbalance of the rotors and the transmitted errors of the gearing are considered, shows that, at theoperating speed, there are not the critical speed.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.1 s.24
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• pp.50-59
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• 2006

Lately, there exist growing demands for the use of CTAs(Cased Telescoped Ammunitions) to increase the firepower of mid-calibre automatic guns despite spatial limitations of armament. In this paper, for automatic CTA guns a rotating chamber mechanism is designed based on parallel index concept. Via dynamic simulations it proves capable of smooth operation even at as high a firing rate as 200spm. Subsequently, motor controllers are synthesized to drive the chamber at any constant speed and also to control positions in the presence of large disturbances caused by the intermittently-rotating load. It is remarkable that we successfully adopted a disturbance observer to treat disturbances only with a moderate bandwidth of the closed-loop system.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.2
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• pp.126-133
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• 2007

Lately, there exist growing demands to increase the firepower of mid-calibre automatic guns despite spatial limitations of armament. In this context, ammunitions of simple cylindrical shape are considered so advantageous that associated automatic guns are under development incorporating an intermittently rotating chamber mechanism. In this paper, relevant subsystems for such guns are to be described, and a digital controller to automate the entire system as well. Via dynamic simulations it proves to function well being able to drive the chamber at any constant speed up to 200spm, which is merely limited by the recoil performance. It is remarkable that the system synchronization idea in use is applicable to any other multi-actuator systems that should operate on the basis of event rather than time.