• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.2
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• pp.167-172
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• 2011

In this paper, a study on variation of an accuracy rate as the gradient of a rifle is shown. In the a state of hostilities, a soldier is not easy to take a shot vertically against the ground. If a soldier shoots as the pistol is inclined, how the accuracy rate is changed. While the pistol is shot, the change of ballistic curve is estimated. And we also verify the accuracy rate through the firing test. Then we compare two results and present some ideas which overcome the decrease of an accuracy rate. Hereafter, it is possible to adapt in the future soldier system and expected that the accuracy rate of the conventional gun is maintained.

• Mass Spectrometry Letters
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• v.4 no.3
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• pp.47-50
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• 2013

An ultra-fast generic LC-MS/MS method was developed for high-throughput quantification of discovery pharmacokinetic (PK) samples and its reliability was verified. The method involves a simple protein precipitation for sample preparation and the analysis by ultra-fast generic LC-MS/MS with the ballistic gradient program and selected reaction monitoring (SRM) mode. Approximately 290 new chemical entities (NCEs) (over 10,000 samples) from 5 therapeutic programs were analyzed. The calibration curves showed good linearity in the concentration range of 1, 2 or 5 to 2000 ng/mL. No significant ion suppression was observed in the elution region of all the NCEs. When approximately 300 plasma samples were continuously analyzed, the peak area of internal standard was constant and reproducible. In the repeated analysis of samples, the plasma concentrations and the area under the curve (AUC) were consistent with the results from the first analysis. These results showed that the present ultra-fast generic LC-MS/MS method is reliable in terms of selectivity, sensitivity, and reproducibility and could be useful for high-throughput quantification and other bioanalysis in drug discovery.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.208-216
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• 2007

As the propellant mass is being accelerated out of the gun chamber along with the projectile, a continuous pressure gradient exists between the end of chamber and the base of the projectile. For this reason, the base pressure-travel curve is very important to design a conventional gun barrel in the interior ballistics, but it is not obtained briefly by empirical or theoretical method. In this paper, a simple relation between chamber pressure and base pressure was determined by the factor of base pressure(Cb) obtained from the experimental method. The simple relation gives a reasonable prediction for the reduction of pressure between the breech and the base of projectile owing to the axial gradient in the gun tube. The predictions have been validated by the infrared screen sensor and the PRODAS(PROjectile Design and Analysis System) for interior ballistic systems. Therefore, the base pressure-travel curve could be calculated from the chamber pressure measured by piezoelectric sensor. The base pressure-travel curve obtained from the simple relation offers initial information to gun barrel designer and is used for calculation of muzzle velocity.