• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.570-588
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• 2022

We scrutinized the acoustic outputs from the 70 shock wave generators of the 15 product models whose technical documents were available, among the 46 ballistic extracorporeal shock wave therapeutic devices of 11 domestic and 6 foreign manufacturers, approved by the Minster of Food & Drug Safety (Rep. Korea). We found that the acoustic Energy Flux Density (EFD), the most popular exposure parameter, was different by up to 563.64 times among shock wave generators at their minimum output settings and by up to 74.62 times at their maximum settings. In the same product model, the EFD was shown to vary depending on shock wave transmitters by up to 81.82 times at its minimum output setting and by up to 46.15 times at its maximum setting. The lowest EFD 0.013 mJ/mm² at the maximum output settings was much lower (2.1 %) than the maximum value 0.62 mJ/mm² at the minimum settings. The Large acoustic output differences (tens to hundreds of times)from the therapeutic devices approved for the same clinical indications imply that their therapeutic efficacy & safety may not be assured. The findings suggest the regulatory authority to revise her guideline to give clearer criteria for clinical approval and equality in performance, and recommend the authority to initiate a post-approval surveillance as well as a test in conformance between the data in technical documents and the real acoustic outputs clinically used.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.6
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• pp.712-720
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• 2016

The purpose of this study was to inspect ballistic match of copper bullet at 4 points by analyzing vertical deviation about shot group of the 5.56 mm common bullets and copper bullets. The 5.56 mm bullet with new copper core material was developed for mitigation of environmental pollution and harmfulness to human body. The results of this study are as follows; using the regression analysis, estimated reference value of ballistic match were 51.6 mm, 64.9 mm, 87.3 mm and 99.6 mm at 25 m, 100 m, 200 m and 250 m range respectively. When analyzing the shooting test data, alternative hypothesis(The vertical deviations are less than the reference value) was adopted as the result of analyzing data using t-test. And the values of data through tool(PRODAS) and standard trajectory equation meet requirements of estimated ballistic match respectively. In conclusion, the level of ballistic match of 5.56 mm copper bullets meets the estimated reference level through regression analysis at 4 points.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.3
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• pp.241-249
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• 2012

Performance analysis of the interior ballistics has been conducted using the 1-D numerical code called IBcode according to the various conditions such as length of ignition-gas injector, amount of ignition-gas, mass of projectile, and drag force of projectile. In case of the length of ignition-gas injector, the 25~100 % of the full-injector length has been considered as well as the mass & mass flow of the ignition-gas. The mass of the projectile 5~70 kg and its drag force of 0~69 MPa have been also considered. Variables such as breech & base pressure, negative differential pressure and muzzle velocity for the performance analysis have been sorted, too. Firing conditions for the optimal performance have been investigated through these variables.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.2
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• pp.181-188
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• 2015

This paper present, the result of the guidance and control law for a course correction munitions(CCM) with 2sets of canards positioned in the rotating nose section. The nonlinear simulation model of the CCM was developed based on 7DOF equation of motion. The ability of correcting position was verified by open-loop control input with nonlinear model. The guidance and control command was constructed by reference trajectory which can be obtained with no control. Finally, the performance of the guidance and control law was evaluated through Monte-carlo simulation. The CEP(Circular Error Probability) was obtained by considering the errors in muzzle velocity, aerodynamic coefficient, wind, elevation and azimuth angle and density.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.2
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• pp.101-104
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• 2013

The actual aircraft flight training can be done, but falls pilots primary flight training skills to the many risks and costs are formidable. It also requires considerable skill to follow at a higher risk of flight training is the same. These things through software simulation training can reduce the risk and cost of the expected risk situations such as virtual reality development and has the advantage that you can try. In this paper, the characteristics and actual aircraft flight dynamics of the considered armed ballistics software platform for game development by designing a student wants to become a pilot in the aircraft is to help you understand.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.1
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• pp.22-29
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• 2011

Using the numerical code for the interior ballistics, the performance of the interior ballistics with the characteristic of the ignition-gas injections has been investigated. The ignition gas has been assumed to be injected into the chamber with 3 cases. As the results of analysis, when the ignition-gas has been injected into all chamber area, the pressure distributions of the chamber of the interior ballistics have been uniform and the differential pressure has been stable. The ignition-gas has been injected into the partial area of the chamber, however, the pressure distributions and the differential pressure have been unstable. The case using the longer ignition injector, therefore, seems to be more suitable to improve the stability of the interior ballistics.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.4
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• pp.551-561
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• 2018

Footprint is defined as ground area that is projected from the outer edges of the battle space protected by a defence system. This concept can be effectively used for making decisions on site selection of anti missile systems to defend against enemy's ballistic missiles. In this paper, simulations of ballistic missile trajectories based on various launch conditions are performed first and then the footprint is derived with engagement zone set as a boundary condition. Results of the simulation with various relative positions between the defense system and defended asset are also presented. The proposed method, in which the trajectories are generated based on launch point of the ballistic missile, has an advantage of approximating the defended area close to reality. Two applications are introduced in the present paper to describe how the derivation of defended area could be utilized in deployment decision of defense systems.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.376-383
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• 2017

This paper describes the gyroscopic stability and the drag characteristics of the smart munition with a course correction fuze(CCF). A ballistic analysis was conducted to figure out the effect of the canards on the gyroscopic stability of the projectile. The analysis used the commercial ammunition performance evaluation software: Projectile Design and Analysis System(PRODAS). In particular, we compared the PRODAS analysis results to real field test results to investigate the influence of the CCF mounted projectile. In addition, some ballistic simulations were carried out to provide the conditions suitable for wind tunnel tests. Experimental results show that the added drag force by the canards is almost uniform regardless of the Mach number when the projectile is at the normal position where the angle of rotation and the angle of attack are both 0 degrees. However, as the angle of attack of the projectile increases, the additional drag force depends on the deflection of the canards.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.3
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• pp.272-281
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• 2015

Miniature smart-bullet is a human-carrying guided missile designed to hit a target easily while having a miniature size. Contrary to the normal missiles, miniature smart-bullet is highly expected to enhance the military strength and survival rate of troops by its compact size readily carriable to a single soldier. In this paper, previously developed techniques, activities and patents of miniature smart-bullet, particularly its structural shape and actuators are surveyed. Furthermore, analysis of required techniques to develop a miniature smart-bullet are also discussed for upcoming conceptual design.

• Journal of Korea Game Society
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• v.18 no.3
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• pp.71-78
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• 2018

Screen-based games often go to many places to install. In this case, there may be a change in the sensor or a difficulty in installation due to a difference in space configuration. Also, it is meaningful to experience the same thing as a real game, but there are cases where it is necessary to control the degree of difficulty to make it feel more fun. In this paper In the process of developing a screen archery game, which is a sensible game similar to screen golf, we will introduce a technique that facilitates installation according to changes in space. And we will explain how to control game difficulty automatically according to user's skill. And we will show you the results of the experiment.