• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.5
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• pp.850-856
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• 2001

Even though the hydraulic servo system has been widely used in industrial and military equipments since it has a lot of advantages, it is not easy to design controller due to the high nonlinearities and the parametric uncertainties. The dynamic behavior of the real process in the hydraulic servo system differs from that described by its model because the model is linearized. Another reason of the difference is caused by the variety of parameters, since the system parameters of the dynamic equation are affected by the operating conditions such as temperature and pressure. In this study, the designing process of the MRNC with a PID compensator is introduced and applied to the load sensing hydraulic servo system. The results show that the designed controller guarantees the robust control performance despite of both the nonlinearities and the parametric uncertainties.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.358-362
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• 2006

Pyro-shock generally refers to the severe mechanical transients caused by the detonation of an ordnance device on a structure. Such device on a structure, including linear explosive, and point explosive are widely used to accomplish in-flight separation of structural elements on aerospace vehicle. And they are a significant cause of launch vehicle failures. The launch vehicle being developed in Korea also uses the explosive for separation events. In this paper, the isolator equipped to small satellite launch vehicle made of PTFE(Teflon) is developed to reduce the separation shock. The test to measure dynamic stiffness of PTFE isolator is performed. This test enables us to find the frequency range of PTFE isolator. And,, pyre-shock test using explosive to evaluate the performance of PTFE isolator is executed. from this study, the isolator conformed to frequency range and load requirement is developed using PTFE instead of rubber.

• Journal of Korea Society of Industrial Information Systems
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• v.21 no.3
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• pp.57-71
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• 2016

Even though the Korean military continued to develop military logistics support systems, sufficient research on logistics service has not been conducted. The main purpose of the research is to examine employees' job satisfaction of logistics units by logistics functions (the ordnance, the supply, the food), and further the relationship between the job satisfaction of logistics units and service quality of the user(combat) units. Some results are as follows. First, the job satisfaction among logistics units was significantly different by functions. Second, the tangible among service quality factors of user units was been significantly different among functional units. Finally, through the post hoc analyses, some meaningful results on service quality were also identified.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.765-770
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• 2015

Thermal batteries are heat-activated primary reserve power sources that use inorganic salt as electrolytes and specially designed to meet extremely long or environmentally severe storage requirements. They are primarily used to deliver high power for relatively short periods in such applications as fuzes, missiles, ordnance and other military applications. In this paper, we describe a general overview and research trends on electrode materials for thermal batteries.

• Journal of Korean Institute of Industrial Engineers
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• v.40 no.4
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• pp.388-395
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• 2014

Nowadays unmanned ground systems are used in supporting of surveillance and explosive ordnance disposal. Also, we expect that will be used to remarkably enhance combat capability through network-based cooperative operations with other combat systems. In order to effectively develop those unmanned systems, we needs a systematic method to analyze combat effectiveness and validate required operation capabilities. In this paper, we propose a practical approach to simulate remote-operated unmanned ground systems by using OneSAF, an US-Army simulation framework. First of all, we design a simulation model of unmanned system by integrating with core components for wireless communications and remote control of mobility and fire. Next, we extend OneSAF functionality to create communication links that connects a remote controller with an unmanned vehicle and define a simulated behavior to operate unmanned vehicles via the communication links. Finally, we demonstrate the feasibility of the proposed model within OneSAF and summarize system effectiveness analysis results.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2801-2808
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• 2022

The synergistic effect of ZrC nanoparticle pining and Re solution in W matrix on the thermal stability of tungsten was studied by investigating the evolution of the microstructure, hardness and tensile properties after annealing in a temperature range of 1000-1700 ℃. The results of metallography, electron backscatter diffraction pattern and Vickers micro-hardness indicate that the rolled W-1wt%Re-0.5 wt% ZrC alloy has a higher recrystallization temperature (1600 ℃-1700 ℃) than that of the rolled pure W (1200 ℃), W-0.5 wt%ZrC (1300 ℃), W-0.5 wt%HfC (1400-1500 ℃) and W-K-3wt%Re alloy fabricated by the same technology. The molecular dynamics simulation results indicated that solution Re atoms in W matrix can slow down the self-diffusion of W atoms and form dragging effect to delay the growth of W grain, moreover, the diffusion coefficient decrease with increasing Re content. In addition, the ZrC nanoparticles can pin the grain boundaries and dislocations effectively, preventing the recrystallization. Therefore, synergistic effect of solid solution Re element and dispersed ZrC nanoparticles significantly increase recrystallization temperature.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.1
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• pp.9-16
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• 2009

In this paper, a method is proposed for the analysis of radiowave receiving characteristics of an ammunition with electric detonator. In this method, an ammunition with electric detonator is modelled as a receiving antenna with its gain obtained by computer simulation or measurement. The induced radiowave power is obtained by inserting the gain of the electric detonator in the antenna coupling formula. Radiowave receiving characteristics at very close distances are obtained by Treasuring the transmission coefficient between a half-wave dipole and the electric detonator model. Radiowave receiving characteristics of the electric detonator in a 105mm tank ammunition are obtained using the proposed method and the safety of the 900 MHz RFID reader on the detonator is assessed.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.196-201
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• 2023

The future is complex and unpredictable. In particular, it is unlikely to occur, but once it occurs, no one knows how it will affect our society if X-event, which has a tremendous impact, is created. This study was conducted only in the climate field to offset the ripple effect of this X-event, and was conducted through in-depth interviews with experts from the Korea Army Research Center for Future & Innovation and the Army College. As a result, it was possible to explore what factors would trigger X-event from their discourse and what X-event would be newly created by spreading them to other fields. Starting with this study, if we accumulate the discourse of experts in various fields such as population, science and technology, as well as climate, and other fields other than the Army, we can predict X-event and offset the threats that may arise.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.159-167
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• 2015

The main purpose of this study is to evaluate the awareness survey on the experience of fire fighting safety education and living safety consciousness of college students in the department of noncommissioned officer. Additionally, making provision of basic references and the effective fire fighting safety education is another important purpose of this study. In order to evaluate the awareness, the survey consist of 43 queries based on 6 queries for general characters, 9 queries for experiences of fire fighting safety education and 30 queries for living safety consciousness. The collected data from survey was analyzed using SPSS 20.0 win program. The interrelationship for general characters was confirmed using analysis of frequency, percentage, independent T-tset, ANONVA analysis, and regression analysis. The results show that the experience of fire fighting safety education and living safety consciousness of students from the combatant branch and ordnance corps are higher than those students from quartermaster corps. This may be attributed to the presence or absence of safety relevant courses on a curriculum. Therefore, the presence of safety courses on a curriculum should be one of important points for improving the experience of fire fighting safety education and living safety consciousness of these college students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.599-604
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• 2018

For missile systems, sustaining high reliability and ensuring economical maintenance are very important. In the Republic of Korea, for most missiles, periodic inspection is mandatory for missiles in the field. Every fixed number of years, they are returned to the ordnance depot to be tested and repaired if faults are found. Almost all missiles have a built-in test (BIT) capability. With the BIT, faulty missiles can be isolated anytime during operations or storage in the launchers. So the reliability and the maintenance costs of the missiles greatly depend on the length of the inspection cycle and the BIT/inspection quality. In this paper, we suggest a model for predicting the storage reliability of missiles subjected to non-periodic tests and periodic inspections, excluding overlapping failures. Some numerical examples are given. This model will be useful for determining the length of the periodic inspection cycle.