• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.5
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• pp.498-509
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• 2015

The existing mobile antenna networks in the military use have been operated by the manual pointing between two antennas. The work presented here describes the study of ATPC(Automatic Tracking and Pointing Control) system between facing antennas and the related tracking and pointing performances. This system is able to automatically track the maximum RSSI(Received Signal Strength Indication) value from the source's RF(Radio Frequency) signal and then control for maintaining the LOS(Line of Sight) between two antennas. The system has three major units; the driving unit consisting of motors, harmonic drives and encoders, the sensor unit with a GPS(Global Positioning System) and AHRS(Attitude and Heading Reference System) and the control unit regulating all the tracking and pointing events. By using PI(Proportional and Integral) controller, this system is able to properly track and point the other antenna under the external disturbance like the wind load. Both the simulation and the experimental works have been successively carried out to prove the performances of the system.

• Journal of the Korea Institute of Military Science and Technology
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• v.23 no.2
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• pp.147-158
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• 2020

Korea Ministry of National Defense has directed the state-of-the-art technology Forces troops structures that can respond to security threats in all directions through the Defense Innovation 2.0, which aims to reorganize the personnel and organizations in response to population decline. An implement of effective analysis to maintain combat power is necessary due to possible restrictions on combat power, especially in division of mobilization where reserve manpower is operated frequently. In this study, the normal operations of the reserve officers were investigated, the direct effects of the combat forces of the reserve officers was analyzed using ARENA modeling, and the budget required to operate the innovation and indirect effects of employment of veterans were studied. The result of the simulation proved to be effective in demonstrating unit combat power when the reserve officer was in full-time operations and economic benefits were also significant in terms of efficiency of defense budget management.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.709-712
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• 2010

A military tactical information communication network uses no base station and all mobile terminal are independent while mobile networks use an infra structure that a fixed base station supports many mobile terminals. A clustering system is more efficient than the existing one in small Ad-hoc network using a limited message size. The development of an adaptive clustering algorithm is necessary to maximize the network efficiency via a study on a clustering for military tactical information communication network.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7871-7874
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• 2015

Background: There is no consensus regarding the selection of treatment options for hepatocellular carcinoma (HCC) after initial transarterial chemoembolization (TACE). This meta-analysis aimed to explore the survival benefit of hepatic resection after initial TACE for the treatment of HCC. Materials and Methods: We searched three major databases to identify all relevant papers comparing the outcomes of hepatic resection after initial TACE versus TACE alone for the treatment of HCC. Hazard ratios (HRs) with 95% confidence intervals (95%CIs) were calculated to evaluate the survival benefit of hepatic resection after initial TACE over TACE alone. Results: Three of 2037 initially identified papers were included. All of them were cohort studies from Asia. There was a significantly better overall survival (OS) in patients undergoing hepatic resection after initial TACE than in those undergoing TACE alone (HR=0.63, 95%CI=0.52-0.76, P<0.00001). The heterogeneity among studies was not statistically significant (P=0.96; I2=0%). Conclusions: Hepatic resection could improve the OS of HCC patients treated with initial TACE. Further randomized controlled trials should be necessary to identify the target population for the sequential use of hepatic resection after initial TACE and to compare the outcomes between patients undergoing hepatic resection after initial TACE session versus those undergoing TACE alone.

• Journal of the Korea Institute of Military Science and Technology
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• v.14 no.4
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• pp.740-746
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• 2011

Thermally activated batteries have good stability, reliability and long shelf life. Due to these characteristics and operational mechanism, thermal batteries are usually applied to military power sources. Especially, Li/$FeS_2$ thermal batteries, which are used mostly in these days, use LiCl-KCl and LiBr-LiCl-LiF as electrolytes. The electrochemistry of thermal batteries have been researched for long time, however, electrochemical study using impedance spectroscopy was not published so much. Through this research, microscopic electrochemical research was investigated with electrochemical impedance spectroscopy(E.I.S). Electrolyte effects on Li/$FeS_2$ thermal battery was researched changing electrolytes, LiCl-KCl and LiBr-LiCl-LiF. Additionally, the salts, which are added to electrolytes, effects on thermal battery were researched. It is expected that the impedance spectroscopy analysis is applicable to not only thermal battery electrochemical study effectively, but also, thermal battery developments.

• Journal of KIBIM
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• v.7 no.4
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• pp.1-7
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• 2017

Since its beginning the military has continued updating its equipments and facilities by modernizing and expanding them. However, with rapidly growing technologies and business management skills, the time for military facilities' evolvement seems unavoidable. The Defense Installations Agency (DIA) has come to a conclusion that application of BIM is necessary. Since its decision, the DIA has been researching the use of BIM and developing guidelines for its application. Nevertheless, the speed of instructions and practical implementation of its model have been behind its plan due to various reasons. To overcome its limitations, the DIA has come up with three-step-solution: basic experience, budgeting, and expansion. Due to numerous number of projects of BIM, it is almost impractical to implement all of them concurrently. The methodological approach of the research employs the Delphi survey method to quantitatively analyze qualitative information drawn from experts' opinions. By applying the Delphi survey method, the first round of the survey drew lists of constraints, BIM application scenarios as well as BIM promotion measures. Afterwards, at the second round of the survey, criticality of each item collected at the 1st round was analyzed to reach a conclusion. Finally, constraints against BIM application were analyzed, and BIM application scenarios and promotion measures for the BIM were introduced.

• Journal of the military operations research society of Korea
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• v.31 no.2
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• pp.28-44
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• 2005

The previous studies approach the field artillery fire scheduling problem as deterministic and do not explicitly include information on the potential scenario changes. Unfortunately, the effort used to optimize fire sequences and reduce the total time of engagement is often inefficient as the collected military intelligence changes. Instead of modeling the fire sequencing problem as deterministic model, we consider a stochastic artillery fire scheduling model and devise a solution methodology to integrate possible enemy attack scenarios in the evaluation of artillery fire sequences. The goal is to use that information to find robust solutions that withstand disruptions in a better way, Such an approach is important because we can proactively consider the effects of certain unique scheduling decisions. By identifying more robust schedules, cascading delay effects will be minimized. In this paper we describe our stochastic model for the field artillery fire sequencing problem and offer revised robust stochastic model which considers worst scenario first. The robust stochastic model makes the solution more stable than the general two-stage stochastic model and also reduces the computational cost dramatically. We present computational results demonstrating the effectiveness of our proposed method by EVPI, VSS, and Variances.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.2
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• pp.224-230
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• 2012

Thermal batteries have excellent mechanical robustness, reliability, and long shelf life. Due to these characteristics as well as their unique activation mechanism, thermal batteries are widely adopted as military power sources. Li(Si)/$FeS_2$ thermal batteries, which are used mostly in these days, use LiCl-KCl and LiBr-LiCl-LiF as molten salt electrolyte. However, it is known that Li(Si)/$FeS_2$ thermal batteries have high internal resistance. Especially, $FeS_2$ cathode accounts for the greater part of internal resistance in unit cell. Many efforts have been put into to decrease the internal resistance of thermal batteries, which result in the development of new electrode material and new electrode manufacturing processes. But the applications of these new materials and processes are in some cases very expensive and need complicated additional processes. In this study, internal resistance study was conducted by adding carbon black and carbon nano-tube, which has high electron conductivity, into the $FeS_2$ cathode. As a results, it was found that the decrease of internal resistance of $FeS_2$ cathode by the addition of carbon black and carbon nano-tube.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.395-403
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• 2016

A cylinder-type underwater vehicle for military use that is running near the free surface at the final homing stage to hit a surface ship target is affected by wave force and moment. Since wave can affect an underwater vehicle running at the depth less than half of the modal wave length, it is important to confirm that the underwater vehicle can work well in such a situation. In this paper, wave force and moment per unit wave amplitude depending on wave frequency, wave direction, and vehicle's running depth were calculated by 3-Dimensional panel method, and the numerical results were modeled in external force terms of six degrees of freedom equations of motion. Motion simulation of the underwater vehicle running in various speed, depth, and sea state were performed.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.501-509
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• 2014

In NCW(Network Centric Warfare) environment, mobile nodes communicate through wireless link. But wireless link provides limited networking performance due to signal interferences or mobility of nodes. So it is quite challenge to acquire enough networking resources and use the resources efficiently. In this paper, we have proposed a P2P based tactical information sharing system which provides satisfactory visual information playout for mobile nodes(i.e., military personnel, vehicle,..) in NCW environment. Our proposed system consists of two components. One is caching-enabled switch which stores tactical information segments at its internal storage and then transports them to mobile nodes when require. Another is centralized scheduling algorithm which exploits networking resources more efficiently. To validate performance of proposed system, we performed series of experiments in wireless network testbed. Results show improved performance in terms of segment-missing ratio, networking resources usage, sharing time, and number of simultaneous playout mobile nodes with acceptable playout continuity(i.e., over 95%).