• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.1
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• pp.16-27
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• 2012

In multi-interface multi-channel(MIMC) based tactical ad hoc networks, QoS support for required operational capacity is one of the main challenging issues for multi-hop transmissions. To support QoS in such a harsh environment, we propose a novel MAC scheme to minimize multi-hop as well as per-hop delay. The current IEEE 802.11 MAC protocols should contend to reserve the channel resource at every hop by each sender. The every-hop channel contention results in a degradation of end-to-end delay for multi-hop transmissions. The basic idea of our scheme is to make a "multi-hop reservation" at the MAC layer by using the modified RTS frame. It contains additional information such as destination information, packet priority, and hop count, etc. In addition, we differentiate the contention window area according to the packet priority and the number of hops to deliver packets in the predefined allowed latency. Our scheme can minimize the multi-hop delay and support the QoS of the critical data in real time(i.e., VoIP, sensing video data, Video conference between commanders). Our simulation study and numerical analysis show that the proposed scheme outperforms the IEEE 802.11 MAC.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.3
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• pp.328-336
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• 2017

The goal of this study is simulation of optimal search pattern of ships based on performance surface which are reflected underwater environmental. The process is as follows. First, temporal and spatial environmental database are extracted in complex environment and input hull mounted SONAR system parameters. The environmental database and SONAR system parameters are substituted to SONAR equations, and calculate signal excess, detection probability, detection range. And then, the performance surface, which can be used to provide operational insight of SONAR detection performance, are pictorialized. Finally, optimal search pattern of ships are simulated using genetic algorithm based on performance surface. And then, we certify optimal search pattern in various ways.

• Journal of National Security and Military Science
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• s.5
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• pp.351-392
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• 2007

Combat Development is process of studying and developing concept, doctrine, weapon systems, organization and training for the improvement of combat capability to be ready present and future warfare. The combat development domain consists of 6 fields Doctrine, Organization, Material, Training, Personnel, and Facilities. The cornerstones of combat development are "How to prepare" and "How to fight" in the future warfare. ROK- TRADOC(Republic of Korea Army Training and Doctrine Command) has implemented combat development that applies CBRS (Concept-Based Requirements System) and "Vision - Capstone concept - operating and functional concept - FOC(Future Operational Capabilities) Requirements". To prepare for the possibility or new types or wars in the future, the creation of new concept and system is essential. Though verification with various instruments, combat power can be secured and exhibited. Combat development by empirical mind estimation means that is no longer relevant.To prepare combat development based on scientific analysis, there is a need for powerful engineering analysis and verification, in order to prepare for uncertain and diverse future battlefield environments. In this thesis, warfighting experiment is essential ways and means to pursue the scientific combat development ; investigated tendency of combat development environment, and analyzed diversification aspects of possible future warfare. In conclusion, concept of campaign experiment and role is the conerstone of scientific combat development; and lays out the roadmap of all affecting components to its development.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.6
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• pp.786-801
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• 2012

The most essential ROC(requirement operational capability) in order to assure the effectiveness of the C4I Systems in NCW Environments is the seamless and stable interoperability between systems. The U.S. Armed Forces that perceived the importance of interoperability, prepared the framework to apply from the proposal of requirement to every step of acquisition process. The Korea Joint Chiefs of Staff is also developing a similar system in order to assure the interoperability between command control(C4I) systems. In the paper, we specify the needs of standardization of test systems and international trends on the technology, and propose an interoperability test & evaluation system based on a standardization conformity method to improve the interoperability test & evaluation for the C4I systems in NCW environments. Finally we show an example of the implementation of the test system and its application to C4I systems to verify the proposed test system.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.1
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• pp.96-107
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• 2014

Tracking the tactical object is a fundamental affair in network-equipped modern warfare. Geodetic coordinate system based on longitude, latitude, and height is suitable to represent the location of tactical objects considering multi platform data fusion. The motion of tactical object described as a dynamic model requires an appropriate filtering to overcome the system and measurement noise in acquiring information from multiple sensors. This paper introduces the filter suitable for multi-sensor data fusion and tactical object tracking, particularly the unscented transform(UT) and its detail. The UT in Unscented Kalman Filter(UKF) uses a few samples to estimate nonlinear-propagated statistic parameters, and UT has better performance and complexity than the conventional linearization method. We show the effects of UT-based filtering via simulation considering practical tactical object tracking scenario.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.248-257
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• 2014

As observed in the recent war, suppression of enemy air defense operation is one of the major tactics, simultaneously conducted with high payoff target. Specifically, our air defense operation should be properly constructed, since the operating environment of our forces mostly consists with mountainous terrain, which makes detections of the enemy difficult. The effective arrangements of low altitude air defense radars can be suggested as a way of improving the detection capability of our forces. In this paper, we consider the location problem of low altitude air defense radar, and formulate it as an Integer Programming. Specifically, we surveyed the previous researches on facility location problems and applied two particularly relevant models(MCLP, MEXCLP) to our problem. The terrain factor was represented as demand points in the models. We verified the optimal radar locations for operational situations through simulation model which depicts simple battle field. In the simulation model, the performance of optimal radar locations are measured by the enemy detection rate. With a series of experiments, we may conclude that when locating low altitude air defense radars, it is important to consider the detection probability of radar. We expect that this finding may be helpful to make a more effective air defense plan.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.413-421
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• 2014

Since the structural temperature of a flight vehicle flying at high speed rises rapidly due to aerodynamic heating, it is necessary for optimum structural design to obtain proper material properties at high temperature by taking into account of its operational environment. For a special alloy, analysis data on strength change due to exposure time to high temperature are very limited, and most of them are for an exposure time longer than 30 minutes for long term operations. In this study, base and weld metal samples of Ti-6Al-4V alloy had been prepared and high temperature tensile tests with induction heating were performed, and then high temperature strength characteristics and strength recovery characteristics through cooling have been analyzed. Pre-tests to determine maximum heating rate were performed, and response characteristics for temperature control were confirmed. As a result, high temperature tensile strength appeared to be lower than that of room temperature, but it was higher than that of high temperature of 30 minite exposure listed in MMPDS. In strength recovery through cooling Ti-6Al-4V alloy has shown higher recovery rate compared with other alloys.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.139-175
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• 2017

The Assembly plenary session on December 3, 2017 passed a Product Liability Amendment bill that introduced clauses concerning consumer burden of proof and punitive damage reimbursement. More specifically, these newly approved provisions will reduce the burden of proof placed on consumers and levy triple punitive damage on suppliers. Significant increases in the number of product-liability lawsuit and the number of related insurance contracts are expected. Since military aircraft are designed for operational purpose(seeking greater combat effectiveness over greater safety) and used in high-risk environment, it is practically impossible to obtain an affordable product-liability insurance, Without having any backup plan, military aircraft manufacturers directly face all sort of liability risks under Product Liability Act, Warrant Liability Act and Non-Performance of Contract Act. The U.S. experienced similar problems when they first implemented their product-liability law in 1970s. There had been a big dispute among legal practitioner, insurance professionals and scholars concerning military aircraft manufacturer's liability. In order to settle the issue, the U.S. Supreme Court has established a new precedent of Government Contractor Defense(GCD). The U.S. government also included an indemnity clause for military aircraft manufacturers in their FMS Contract with the Korean government. Likewise, Korean military aircraft manufacturers should 1) clearly understand their current position that they cannot afford expensive product-liability insurance and the cost is not accounted in the military procurement calculation, 2) estimate potential liability risks with the ongoing overseas export expansion in mind, 3) set up appropriate risk management measures through regulatory reform and policy development.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.369-376
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• 2014

The national Logistics Information system has been rapidly developed on account of the dramatic improvements in the military's logistics support system and supply support system, making a transition from manual work system to computerized work system. Supply level, however, does not reflect these changes in the overall logistics environment and still retains the state it was in the 1970s. This research uses the accumulated data from the equipment maintenance information system developed in the year 2009 to analyze RWT(Requisition Wait Time) and CWT (Customer Wait Time). The analysis estimated the realistic transportation and ordering time and led to the conclusion that the differentiated ASL operation system that considers demand level should be adopted instead of the uniform ASL employment system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.256-261
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• 2014

Endurance test procedures of multipurpose tactical vehicle is constructed by comparing the Korea defence standard and TOP-2-2-506. The plan was to make the best reflect the operational environment and the actual production purposes. Endurance test of multipurpose tactical vehicle more stringent than the existing other military vehicles validation procedures. But the test plan, it is possible to reduce the cost and schedule of long verification that occurs because of the Endurance test. Through a comparison of the dynamic characteristic analysis, change of test center was to ensure the reliability and validity.