• 한국군사과학기술학회지
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• 제22권1호
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• pp.81-92
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• 2019

Stealth means the reduction of all signature including the reflection/emission of radar, infrared, visible light and audio signals. Stealth aircraft can significantly improve the penetration capability, the combat survivability and the mission effectiveness. This paper presents the basic concept, the key elements and the application examples of stealth aircraft technology. Also it briefly describes the effect of the modern stealth aircraft on the future air warfare.

• 한국진공학회지
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• 제17권6호
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• pp.501-510
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• 2008

비행체를 레이더의 시야에 들어나지 않도록 하기 위한 은신 (stealth) 기술은 일반적으로 비행체 표면에 특수도료를 도포하는 방식을 사용하여 실현하고 있지만 요즈음 플라즈마의 전자기파 흡수 능력을 이용하려는 연구가 활발히 진행되고 있다. 대기압 플라즈마가 은신기술에 응용될 수 있는가 우선 물리적인 타당성을 알아보기 위해 이 논문에서는 대기층에서 비행하는 비행체 표면을 어떤 정도의 플라즈마로 얼마나 덮어야 원하는 은신 기능을 나타낼 수 있는지 판단할 수 있도록 비 자장, 비 균일, 평판 플라즈마 모델을 사용하여 계산한 결과를 제시하고 논의한다.

• 한국군사과학기술학회지
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• 제18권4호
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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.

• 한국군사과학기술학회지
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• 제25권3호
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• pp.251-258
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• 2022

Infrared stealth technology used in aircraft is applied to reduce the infrared signal by controlling surface temperature and emissivity using internal heat sink, low emissivity material or metamaterial. However, there is one part of the aircraft where the use of this technology is limited, and that is the radome. Especially, radome should have transmittance for the specific radio frequency, therefore, common stealth technology such as emissivity control surfaces cannot be applied to radome surface. In this study, we developed metal nano-coating for infrared stealth which is applicable to radome surface. We designed slot-type pattern for frequency selective transmission in X-band, and also controlled thickness of metal nano-coating for long wavelength infrared emissivity control. As a result, our infrared stealth surface for radome has 93.2 % transmittance in X-band and various infrared emissivities from 0.17 to 0.57 according to nano-coatings thickness. Also, we analyzed infrared signature of radome through numerical simulation, and finally reduced contrast radiant intensity by 97.57 % compared to polyurethane surface.

• 한국정보기술학회 영문논문지
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• 제9권1호
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• pp.1-10
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• 2019

In recent years, information collection of attacks through stealth port scanning technology has become more sophisticated. The most commonly used Nmap port scanner supports a variety of stealth scanning technologies along with the existing scanning techniques. Nmap also supports Idle scan that is different from conventional stealth scans. This is a more sophisticated stealth scan technique by applying the SYN scan and ACK scan techniques. In previous studies, the detection of Idle scanning was on zombie system, but was not on victim system. In this paper, we propose an effective detection method of Idle scan on victim system. The Idle scanning is composed of two stages; they are probing the zombie and victim system and scanning the victim system. We analyzed the characteristics of the two stages. The characteristics, we captured, are that SYN and RST packets are different from normal packet. We applied them to detection method, then Idle scanning is detected effectively.

• Journal of Pharmaceutical Investigation
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• 제30권1호
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• pp.13-19
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• 2000

$Stealth^{\circledR}$ liposomes entrapped with streptokinase were prepared to improve the physical stability of conventional liposomes. The particle size distribution, dissolution rate and entrapping efficiency of the $Stealth^{\circledR}$ liposomes were studied. The entrapping efficiency of streptokinase into conventional liposomes was proportional to the total lipid and cholesterol amounts. In $Stealth^{\circledR}$ liposomes, the entrapping efficiency of streptokinase was increased with the increase of DPPE-PEG(5,000) amount. The particle size of $Stealth^{\circledR}$ liposomes decreased with the increase of DPPE-PEG(5,000) amount. The dissolution rate of streptokinase from conventional liposomes was decreased by addition of cholesterol. The dissolution rate of streptokinase from the $Stealth^{\circledR}$ liposomes was also decreased by addition of DPPE-PEG(5,000).

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 춘계학술대회
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• pp.555-558
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• 2009

본 논문은 상대방으로부터 탐지를 최소화시키는 스텔스 기술을 분석하고, 대부분의 레이더 반사 단면적 감소는 형상화로부터 기인되며, 특별한 부위에는 RAM을 이용하여 최소화 시키는 것을 확인하였다. 따라서 RF 스텔스를 위한 밀리미터파 대역의 레이더 반사 단면적을 최소화시키는 측면에서 94 GHz에서 전파흡수량 17 dB로 98 %를 흡수하는 RAM을 설계 및 제작하였다. 결과적으로 개발된 RAM을 플랫폼에 적용시 상대방으로부터 레이더 탐지거리를 62 % 축소시키는 효과를 얻을 수 있다.

• 한국군사과학기술학회지
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• 제17권6호
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• pp.764-772
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• 2014

The stealth performance of supersonic aircraft in recent air battlefield is one of the most significant feature for latest fighters. Especially, as the technology is advancing, the IR stealth capability becomes more important because of its passive characteristic. To design an aircraft with stealth capability, we must know how much the IR signature is generated from the aircraft. Also, predicting the IR signature of enemy's aircraft is tactically crucial. In this study, we calculated MWIR and LWIR infrared signature of $5^{th}$ generation supersonic aircraft against air-to-air and surface-to-air threat using IR simulation code and CFD coupled procedure.

• International Journal of Aeronautical and Space Sciences
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• 제17권1호
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• pp.101-108
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• 2016

The RCS characteristics of stealth modified three-surface aircraft are analyzed in this paper. Prototype A is built with CATIA software and the three-dimensional digital models of modified stealth three-surface B and C are also designed based on carrier-based aircraft Su-33; the numerical simulation of RCS characteristics of three-surface aircraft is conducted with RCSAnsys software based on physical optics method and the method of equivalent currents; The following results are obtained by comparative analysis and mathematical statistics: (1) by the use of physical optics method and equivalent electromagnetic current method, the scattering intensity for each part of the model and RCS characteristic of the aircraft can be analyzed efficiently and accurately; (2) compared with model A, the mean RCS value of model B is reduced to 14.1% in forward direction and 48.1% in lateral direction; (3) compared with model A, the mean RCS value of model C decreases to 11.4% in forward direction and 21.6% in lateral direction. The results are expected to provide theoretical basis and technical support to the conceptual design of aircraft and stealth technology research.

• 한국정보통신학회논문지
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• 제13권6호
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• pp.1241-1246
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• 2009

본 논문은 상대방으로부터 탐지를 최소화시키는 스텔스 기술을 분석하고, 대부분의 레이더 반사 단면적 감소는 형상화로부터 기인되며, 특별한 부위에는 RAM을 이용하여 최소화 시키는 것을 확인하였다. 따라서 RF 스텔스를 위한 밀리미터파 대역의 레이더 반사 단면적을 최소화시키는 측면에서 94 GHz에서 전파흡수량 17 dB로 98 %를 흡수하는 RAM을 설계 및 제작하였다. 결과적으로 개발된 RAM을 플랫폼에 적용시 상대방으로부터 레이더 탐지거리를 62 % 축소시키는 효과를 얻을 수 있다.