• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.105-113
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• 2010

SAR(Synthetic Aperture Radar) has characteristics well-suited for the measurement of geophysical parameters during day and night in all weather conditions. Recently, SAR data with high resolution acquired by satellites became available to the public. In such data, many features and phenomena of geometric structure of man-made objects and natural environments become observable. In this paper, we discuss main considerations including geometric distortion and coregistration for efficient utilization of high resolution SAR images. And, various advanced technologies in SAR application fields are introduced.

• Journal of Magnetics
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• v.20 no.2
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• pp.161-165
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• 2015

The Permanent Magnet Brushless DC (PMBLDC) motors have been used in modern industrial factories, hazardous chemical process, modern medical devices, and especially in advanced military devices such as army drones. By considering their sensitive role in the industrial and military applications, their optimal design has a real concern. This paper proposes a method for optimal eco-design of a PMBLDC motor using improved tabu search optimization. The objective function is based on losses, volume and cost. Electrical and mechanical requirements and other limitations are combined into constraints of problem. Also, finite element analysis has been used for verifications in magnetic mode.

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.83-96
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• 2002

The Analytic Hierarchy Process (AHP) is well suited to group decision making and offers numerous benefits as a synthesizing mechanism in group decisions. To date, the majority of AHP applications have been in group settings. One reason for this may be that groups often have an advantage over individual when there exists a significant difference between the importance of quality in the decision and the importance of time in which to obtain the decision. Another reason may be the best alternative is selected by comparing alternative solutions, testing against selected criteria, a task ideally suited for AHP. In general, aggregation methods employed in group AHP can be largely classified into two methods: geometric mean method and (weighted) arithmetic mean method. In a situation where there do not exist clear guidelines for selection between them, two methods do not always guarantee the same group decision result. We propose a simulation approach for building group consensus without efforts to make point estimates from individual diverse preference judgments, displaying possible disagreements as is natural in group members'different viewpoints.

• Journal of the military operations research society of Korea
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• v.25 no.1
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• pp.107-132
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• 1999

In this study, we are concerned with the comparative aspects of five selected methods of decision making with respect to their adequacy in helping complex decisions about real-world problems. We examine the methods in terms of outlines, procedures and advantages/disadvantages to identify similarities and differences among them with the aim of showing which method is more likely to gain greater attention both in academia and in practice. To illustrate different courses of deployment of the methods, we offer an application with a case of airport transportation project in this paper. Some discussions on AHP and other methods are presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.5 no.2
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• pp.91-102
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• 2002

불연속 전송선로를 해석하기 위한 유용한 방법으로서 유한요소법이나 공간도메인법등과 같은 주파수영역 해석법과 선로제작에 기초한 파라미터 측정법등이 사용된다. 시간영역의 유한차분법은 한번의 모의실험을 통해 주파수 의존적인 파라미터값을 구할수있어 불연속선로를 해석하는데 매우 효과적이다. 본 논문에서는 마이크로 스트립에 기초한 몇가지 형태의 2 포트 불연속 회로망 즉, 케스케이된 스텝 불연속 선로와 레이스트렉 지연선 및 단일 스터브 필터에 대한 정확한 모델링과 해석을 위하여 시간영역의 유한차분법의 적용방법이 논의된다. 2 포트 회로망으로 구성된 평면형 마이크로 스트립 불연속선로를 해석하기 위하여 일반적으로 분산 파라미터에 기초한 해석절차가 사용된다. 주파수 의존적인 분산 파라미터는 시간영역의 유한차분법에 의해 모니터된 입사, 반사 및 투과된 전압으로 부터 고속푸리에 변환을 통해 얻어지고, 또한 그 결과를 공간-스펙트랄 방법 및 모멘트 방법의 결과와 비교함으로써 시간영역의 유한차분법이 다양한 형태의 불연속 선로에 성공적으로 적용됨을 볼 수 있다.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.4
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• pp.369-375
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• 2015

In this paper, transparent circuit analog radar absorbing structure with angular stability for stealth aircraft canopy was proposed and designed. To obtain wideband electromagnetic absorption, optical transparency and smaller thickness, we proposed the novel FSS(Frequency Selective Surface) for X-band and implemented the resistive FSS and PEC(Perfect Electric Conductor) plane using ITO(Indium Thin Oxide) coating with optical transmissivity of 90 %. Reflection loss characteristics for different incident angles of both TE(Transverse Electric) and TM(Transverse Magnetic) polarizations are presented through simulations. We then fabricated the proposed structure to verify the simulation results. The comparisons between the simulation and measured results show good agreements. The results also show that the proposed radar absorbing structure can provide better frequency stability for different incidence angles and polarizations as well as optical transparency. We can apply this proposed structure to the canopy of stealth aircraft and other stealth applications for visible transparency.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.6
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• pp.733-742
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• 2017

LADARs are used for important sensors in various applications, for example, terrain information sensors in self driving cars, safety sensors for factory automation, and 3D map constructions. This study develop important component technologies to improve the performance of a LADAR system under development in Korea. The component technologies include diode temperature regulation, reducing distance error in outdoor environment, and signal processing technique for better detection of distant objects. This paper explains the suggested component technologies and experimental results of the developed LADAR system. Also, the developed system is operated and tested an a single axis driving platform to acquire 3D information from 2D LADAR.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.34-41
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• 2006

This paper describes the general considerations and operational applications of aircraft night vision goggle(NVG). The operators should recognize the NVG characteristics, natural night light sources and interoperability between them. And they have to keep attention to the method to take steps to avoid misperceptions, illusions during flight, and the negative impact on the effectiveness and safety of the mission. The considerations based on the interoperability between NVG and night operation suggest the evaluation items of NVG field test and flight test.

• Journal of the military operations research society of Korea
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• v.27 no.2
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• pp.134-148
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• 2001

In this paper, air-defense simulation model, called "DADSim", will be introduced. DADSim(Distributed Air Defense Simulation Model) was developed by Modeling&Simulation Lab of K.N.D.U.(Korea National Defence Univ) Weapon Systems Department. This model is an analysis-purpose model in the engagement-level. DADSim can simulate not only the global air-defense or Korean Peninsula but also the local air-defense or a battle field. DADSim uses the DTED(digital terrain elevation data) LeveII it for the representation of peninsula terrain characteristics. The weapon systems cooperated in the model are low/medium-range missile systems such as HAWK, NIKE, SAM. DADSim was designed in the way of object-oriented development method, implemented by C++ language. The simulation view is an event-sequenced object-orientation. For the convenience of input, output analysis, GUI(Graphic User Interface) of menu, window, dialog box, etc. are provided to the user, For the execution of DADSim, Silicon Graphic IRIX 6.3 or high version is required. DADSim can be used for the effectiveness analysis of­defence systems. Some illustrative examples will be shown in this paper.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.2
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• pp.215-223
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• 2019

A high temperature adhesive development which is crosslinked in low temperature is necessary for aerospace application because of thermal expansion mismatches of various substrates. For this purpose, we have designed and fabricated several formulations with high temperature epoxy resins, crosslinkers and additives considering various working conditions and high service temperature. As a result, some formulations showed higher adhesive strengths than Hysol EA 9394/C2 which is widely used for aerospace applications. We also have studied and summarized the mechanical properties of the best development adhesive in both room and high temperatures.