• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.2
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• pp.171-176
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• 2016

In this paper, the integration of the firing test stages at the acceptance test of the propelling charge has been studied using statistical analysis on the basis of the test data of K676 and K677 propelling charge for K9 self propelled howitzer. Acceptance test of K676 / K677 propelling charge consists of 3 stages and each stage is charge assessment test, charge uniformity test and charge proving ground test. Many of rounds are fired and much money is spent to prove the charge performance at each stage. The result of t-test shows that there is no difference between charge uniformity and charge proving ground test stage of K676 and K677 propelling charge.

• Journal of Internet Computing and Services
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• v.21 no.5
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• pp.39-48
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• 2020

Recently, the study and development of environment-friendly energy technique have increased in worldwide due to environmental pollution and energy resources problems. In vehicle industry, the development of electric vehicle(EV) is now on progress, and also, many other governments support the study and development and make an effort for EV to become widely available. In addition, though they strive to construct the EV infra such as a charge station for EV, the techniques related to managing charge demand and peak power are not enough. The standard of EV communication has been already established as ISO/IEC 15118, however, most of implemented EVs and EV charge stations do not support any communication between each of them. In this paper, an improved slow charge scheme for non-communication EVs is proposed and designed by using predicting charge demand. The proposed scheme consists of distributed charge model and charge demand prediction. The distributed charge model is designed to manage to distribute charge power depending on available charge power and charge demand. The charge demand prediction is designed to be used in the distributed charge model. The proposed scheme is based on the collected data which were from EV slow charge station in business building during the past 1 year. The system-level simulation results show that the waiting time of EV and the charge fee of the proposed scheme are better than those of the conventional scheme.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.339-345
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• 2016

This paper is concerned with the numerical simulation result of pressure propagation to the main charge by warhead penetration into concrete targets. In this study, we developed on-line pressure measurement method in the main charge during warhead penetration. Using the on-line pressure measurement method, we successfully recorded the pressure-time history in the main charge during the field penetration test. Then we compared result of numerical simulations with test data and found that the simulation results are in good agreement with the test results. Finally, through the numerical calculations it is concluded that the installation of liner is effective in reducing pressure level produced in the main charge.

• Journal of Powder Materials
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• v.6 no.1
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• pp.69-74
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• 1999

The microstructure of the reagion of carters, created by Cu and W-Cu shaped charge jets, in a 1020 mild steel target has been intestiaged. The region ahead of the crater created by the Cu shaped charge jet, reveals dramatic grain refinement implying the occurrence of a dynamic recrystallization, while that of W-Cu one dose a martensitic transformation indicative of heating up to an austenitic region followed by rapid cooling.The impacting pressure calculated when the W-Cu shaped charge jet encounters the target is higher than that of the Cu one. The micro-hardness of the region ahead of the crater created by the W-Cu shaped charge jet is also higher than that of the Cu one. The microstructure of W-Cu slug remained in the inside of the craters depicts the occurrence of the remarkable elongation of W particles during the liner collaphse. From these results, the microstructural variation of the region ahead of the crater with Cu and W-Cu shaped charge jets is discussed in trems of the pressure dependency of the transformation region of ferrite and austenite phases.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.397-404
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• 2019

Linear Shaped Charge (LSC) that is widely used as separation system in aerospace system has to charge lots of explosives due to lack of uniformity. In addition, it is hard to optimize shape of liner and explosives because of manufacturing process. In order to overcome aforementioned drawbacks, Precision Linear Shaped Charge (PLSC) is currently under development. PLSC is made in two steps: prepare liner independently and charge explosive uniformly. In this study, PLSC is designed to have proper amount of explosives and penetration test of PLSC with different stand-off distance from liner to target is conducted to confirm penetration performance. Based on the penetration test results of PLSC, the numerical analysis method using AUTODYN is established and verified. Penetration mechanism and characteristics of PLSC is analyzed from the numerical and experimental results.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.574-581
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• 2015

In this paper, the effect of high voltage current pulse against shaped charge jet was analyzed through the visualization of jet behavior using flash X-ray and comparison of depth of penetration(DOP) into RHA(Rolled Homogeneous Armor) witness plates. The behavior of jet particles has been acquired using a flash X-ray equipment when current pulse was applied into the metal jet of a shaped charge(SC) warhead. Typical results such as jet breakup and radial jet dispersion, which are due to electromagnetic pressure by current pulse, have been obtained. Dozens of penetration experiments using a shaped charge with 55 mm diameter were performed according to various combinations of major parametric variables such as electrode spacing, standoff distance from SC warhead to electrode, and charge voltage. Subsequently, interrelations between major parametric variables and DOPs into RHA were analyzed.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.3
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• pp.387-393
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• 2014

The combustion pressure and thrust of aft-igniter were measured to investigate the characteristics of ignition charge. Granule and pellet shape ignition charge of $BKNO_3$ and MTV(Magnesium-Teflon-Viton) were used for igniters. Ignitions with granule charges show abrupt increases of combustion pressure and thrust compared to those of pellet charge. $BKNO_3$ igniter shows higher combustion pressure than MTV igniter due to higher combstion rate. Mg particle size affects the combustion pressure of MTV igniter.

• Land and Housing Review
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• v.4 no.1
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• pp.99-105
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• 2013

Development Charge System was introduced in 1989 to recapture development gains, however, it has been revised more than 20 times since then. The reason for such frequent revisions was that estimating development cost was too composite and indefinite. Therefore it is required that estimating method of development cost should be simplified in order to minimize conflicts among diverse parties. To support the recent revision of 'Restitution and Development Gains Act', this study verified several alternatives of applying standardized costs per area under specific size of development and suggested policy implications. For analysis data, 9,362 Development Charge and cost data of si gun gu for recent 3 years were used. The results showed that dividing Seoul Metropolitan Area (SMA) and non-SMA made a significant difference and definite divisions among regional groups. The result of this study could minimize social conflicts as well as contribute in realizing the public concept of land policy by revising Development Charge System.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1674-1688
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• 2019

As environmental pollution and fossil fuel energy problems from fuel vehicle have occurred, the interest of electric vehicle(EV) has increased. EV industry and energy industry have grown dynamically in these days. It is expected that the next generation of primary transportation will be EV, and it is necessary to prepare EV infra and efficient energy management such as EV communication protocol, EV charge station, and smart grid. Those EV and energy industry fields are now on growth. Also, the study and development of them are now in progress. In this paper, distributed charge signal processing software for smart slow and quick EV charge is proposed and designed for dealing with EV charge demand. The software consists of smart slow and quick EV charge schedule engine and EV charge power distribution core. The software is designed to support two charge station types. One is normal EV charge station and the other is bus garage EV charge station. Both two types collect the data from EV charge stations, and then analyze the collected data. The software suggests optimized EV charge schedule and deliveries EV charge power distribution information to power switchboard system, and the designed software is implemented on embedded system. It is expected that the software provides efficient EV charge schedule.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.433-437
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• 1998

Equalize SOC of the cell which effect on the charge.discharge ability and the efficiency of the battery, through the charge.discharge characteristic test of the battery source, and develope the high efficiency charge.discharge system in the series HEV have a constant engine-generator output. For this, in this paper, establish the electrical model and the condition of high efficiency charge.discharge, and proposed the improvement method of charge.discharge characteristic in the battery source that consist of twenty Ni-MH cells connected serial/parallel