• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.6
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• pp.124-132
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• 2011

In a modern electronic warfare, radar signal environments become more denser and complex. Therefor the capability of reliable signal analysis techniques is required for ES(Electronic warfare Support) system to identify and analysis individual emitter signals from received signals. In this paper, we propose the new signal grouping algorithm to ensure the reliable signal analysis and to reduce the cost of the signal processing steps in the ES. The proposed grouping algorithm uses KDE(Kernel Density Estimator) and its CDF(Cumulative Distribution Function) to compose windows considering the statistical distribution characteristics based on the radar frequency modulation type. Simulation results show the good performance of the proposed technique in the signal grouping.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.87-97
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• 2019

This paper focuses on the SE concept based on the weapon system design, which is the lack of systematic research at the stage of military requirements creation prior to acquisition management phase. Influence factors were derived by focusing on the core issues that were at issue in the process of requirements analysis, requirements verification, and business management in recent years. Next, the impact factor was prioritized using the AHP technique and then alternatives were suggested. As a result, through the hierarchical analysis process, 'substantiation of necessity' was found to be the most important factor in the large category, and 'satisfaction of the operating concept' was the most important factor. In addition, as a result of calculating the final weight for each nutritional factor, it was analyzed in order of 'enemy threat response ability', 'response to operational environment change', 'performance considering operational environment', and 'guaranteed power generation'. The results of this analysis suggest which factors should be focused on, firstly, based on the concept of SE by the military and JCS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1608-1618
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• 2016

In this paper we introduce a graph theory approach to solve the frequency assignment problem(FAP) for military communication network. Prior algorithms are implemented adaptively to the problem, and enhanced algorithms are proposed to show that their results approximately approached the optimum performance. We also proposed polarization assignment algorithms to enhance the FAP performances.

• The Journal of Korea Robotics Society
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• v.13 no.3
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• pp.151-156
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• 2018

Military robots are expected to play an important role in the future battlefield, and will be actively engaged in dangerous, repetitive and difficult tasks. During the robots perform the tasks a human operator controls the robots in a supervisory way. The operator recognizes battlefield situations from remote robots through an interface of the operator control center, and controls them. In the meantime, operator workload, controller interface, robot automation level, and task complexity affect robot operability. In order to assess the robot operability, we have developed ROSim (Robot Operational Simulator) incorporating these operational factors. In this paper, we introduce the results of applying ROSim experimentally to the assessment of reconnaissance robot operability in a battle field. This experimental assessment shows three resulting measurements: operational control workload, operational control capability, mission success rate, and discuss its applicability to the defense robot research and development. It is expected that ROSim can contribute to the design of an operator control center and the design analysis of a human-robot team in the defense robot research and development.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.7 s.98
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• pp.661-670
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• 2005

In this paper, the microstrip $90^{\circ}$ hybrid to provide -3dB coupling and $90^{\circ}$ phase difference at broadband frequency range of 2 to 6 GHz is designed. This proposed hybrid is composed of 3-section. The two outside section are realized by symmetrical edge coupled lines, but on the other hand the middle section consists of VIP(Vertically Installed Planar) circuit. The ground part of VIP circuit is partially removed to get tight coupling, particularly. This hybrid is easy to realize due to microstrip structure and has good holing flexibility by taking advantage of VIP circuit as a control point of optimization. The proposed hybrid provide satisfactory performance as compared with simplicity of structure and fabrication first of all.

• Journal of electromagnetic engineering and science
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• v.9 no.3
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• pp.118-123
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• 2009

This paper discusses the design and fabrication of a reference signal generator for a naval radar system, including the vibration environment test. The transmit signals of the S-band radar system are synthesized by the reference signal and the phase noise must lower than - 130 dBc/Hz at a 10 kHz offset frequency. To achieve this specification, the phase noise of the reference signal needs to be less than -165 dBc/Hz at a 10 kHz offset. For achieving very low phase noise performance by the reference signal generator, the phase locked loop technique is applied with a 10 Hz loop bandwidth. Also, this reference signal generator has ${\pm}0.35\;ppb$ short-term stability to minimize instant phase errors and high vibration sensitivity against a ship's shaking, unbalanced rotating of antennas and so on.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.6
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• pp.55-59
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• 2008

For effective mobility control of UGV(unmanned ground vehicle), the terrain cover classification is an important component as well as terrain geometry recognition and obstacle detection. The vision based terrain cover classification algorithm consists of pre-processing, feature extraction, classification and post-processing. In this paper, we present a method to classify terrain covers based on the color and texture information. The color space conversion is performed for the pre-processing, the wavelet transform is applied for feature extraction, and the SVM(support vector machine) is applied for the classifier. Experimental results show that the proposed algorithm has a promising classification performance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.6
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• pp.513-518
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• 2018

Nitrogen charging trailer applied to KUH-1 is a device to charge Nitrogen in main front wheel buffer, tail bumper buffer, brake accumulator and tire of aircraft. As the name suggests, it is a device that has mobility along with nitrogen charging. Originally supplied by Tronair in the United States, it was imported from Korea, and the locally developed product not only satisfies the performance of the existing product, but also designed to be easier than the product introduced in the operation. It was selected as the joint investment project of the 15th civilian government building, and development needs analysis and test evaluation were carried out under the support of development and management of Korea Aerospace Industries and Defense Agency for Technology and Quality.

• Journal of Korean Society for Quality Management
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• v.46 no.3
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• pp.509-522
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• 2018

Purpose: The purpose of this study was to propose more accurate mathematical model which can represent result of government quality assurance activity, especially corrective action and flaw. Methods: The collected data during government quality assurance activity was represented through histogram. To find out which distributions (Poisson distribution, Zero-Inflated Poisson distribution) could represent the histogram better, this study applied Pearson's correlation coefficient. Results: The result of this study is as follows; Histogram of corrective action during past 3 years and Zero-Inflated Poisson distribution had strong relationship that their correlation coefficients was over 0.94. Flaw data could not re-parameterize to Zero-Inflated Poisson distribution because its frequency of flaw occurrence was too small. However, histogram of flaw data during past 3 years and Poisson distribution showed strong relationship that their correlation coefficients was 0.99. Conclusion: Zero-Inflated Poisson distribution represented better than Poisson distribution to demonstrate corrective action histogram. However, in the case of flaw data histogram, Poisson distribution was more accurate than Zero-Inflated Poisson distribution.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.517-525
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• 2016

In this research, the effect of the pressure control of cooperative control system with regenerative brake for a military series hybrid-electric vehicle was studied. A cooperative control system with regenerative brake was developed to maximize regenerative energy from electric traction motors of the vehicle. However, the pressure control method of the system was modified to solve a time delay problem and it deteriorates the performance of the system. A Simulink model including the hybrid-electric components, the cooperative control system with regenerative brake, and the vehicle dynamics was developed and used to find a solution. The regenerative energy ratio with respect to the whole brake energy was increased in this research from less than 60 % to over 80 %.