• 한국군사과학기술학회지
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• 제15권4호
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• pp.417-423
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• 2012

Radar Cross Section(RCS) is a measure of how detectable an object is with a radar. A larger RCS indicates that an object is more easily detected. Informally, the RCS of an object is the cross-sectional area of a perfectly reflecting sphere that would produce the same amount of reflection strength as the object in question would. In order to estimate RCS of aircraft weapons the external surface is modeled as a collection of simple shape elements. And the overall RCS is estimated as a vector sum of configuring elements' cross-sections which are well known given by analytic formulae. A RCS estimation code is developed for a typical shape of Air-To-Surface bombs and missiles. Size of weapons and location of fins are implemented in the code in addition to the presence of canards. The ability to predict radar return from flying vehicles becomes a critical technology issue in the development of stealth configurations. This simplified method of RCS estimation is known to be fast and accurate enough in an optical region of high frequency incident radio wave.

• 한국군사과학기술학회지
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• 제23권4호
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• pp.337-345
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• 2020

The Weapon-Target Assignment(WTA) problem can be formulated as an optimization problem that minimize the threat of targets. Existing methods consider the trade-off between optimality and execution time to meet the various mission objectives. We propose a multi-agent reinforcement learning algorithm for WTA based on mean field game to solve the problem in real-time with nearly optimal accuracy. Mean field game is a recent method introduced to relieve the curse of dimensionality in multi-agent learning algorithm. In addition, previous reinforcement learning models for WTA generally do not consider weapon interference, which may be critical in real world operations. Therefore, we modify the reward function to discourage the crossing of weapon trajectories. The feasibility of the proposed method was verified through simulation of a WTA problem with multiple targets in realtime and the proposed algorithm can assign the weapons to all targets without crossing trajectories of weapons.

• 보존과학회지
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• 제7권2호
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• pp.45-53
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• 1998

조선시대의 정공청 장군의 유품 중 무기류의 주요한 재료인 목재의 보존을 위한 사전조사로써 재질조사와 수종식별 및 보존처리를 하였다. 재질의 구조적인 조사는 육안 및 X-ray로 실시하였으며 유물의 상태는 일부 미세한 할렬이 나타났지만 대체로 양호하였다. 광학현미경을 통한 수종조사 결과, 각 유품의 해당수종은 화살대가 대나무류, 깃봉이 육박나무, 깃대가 물푸레나무류, 족자대가 소나무이었다. 보존처리를 위한 치수 안정화 약재로써 세틸 알코올로 처리하였으며, 처리 후 접합고정에는 초산 비닐계와 에폭시계 접착제를 사용하였다.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.575-581
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• 2013

In this paper, we experimentally investigated the effects of attached cylindrical tripwires on the aerodynamic performance. The research was carried out with a simple two-dimensional (2-D) rectangular airfoil fabricated from thin flat-plate aluminium, with elliptical leading and trailing edges. Tripwires of varying widths and thicknesses, and attack angles of $-5^{\circ}{\sim}20^{\circ}$ were used to investigate the aerodynamic characteristics (e.g. lift and drag forces) of the airfoil. We found that attaching the tripwires to the lower surface of the airfoil enhanced the lift force and increased the lift-to-drag ratio for low attack angles. However, attaching the tripwires to the upper surface tended to have the opposite effects. Moreover, we found that attaching the tripwires to the trailing edge had similar effects as a Gurney flap. The aerodynamic characteristics of the flat-plate airfoil with tripwires can be used to develop passive control devices for aircraft wings in order to increase their aerodynamic performance when gliding at low attack angles.

• 한국정보통신학회논문지
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• 제17권5호
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• pp.1253-1258
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• 2013

2010년 천안함 침몰로 인해 수중 폭발체의 위험성이 전시 뿐만 아니라 평시에도 대단히 중요하게 다뤄져야 하며, 그에 따른 방어대책이 필수적으로 필요함을 인지하게 되었다. 다양한 수중무기폭발 체계 중 대표적인 비닉(庇匿) 무기체계인 기뢰를 중심으로 탐지수단, 탐지방법, 위험 제거 방안 등에 대해 연구하며, 특히 탐지를 위한 대표적인 센서인 자력계 등의 데이터를 참조하여 발화확률 모사 시스템을 모델링하고, 아 해군 보유 함형에 따른 수심별 해석을 통해 발화확률 등을 시뮬레이션 하여 효과적인 탐지, 위협제거 및 궁극적인 대기뢰전 전술 등을 연구/제안한다.

• Nuclear Engineering and Technology
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• 제37권4호
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• pp.317-326
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• 2005

The burning-out of excess plutonium from the reprocessing of spent nuclear fuel and from the dismantlement of nuclear weapons is recently emphasized due to the difficulties in securing the final repository for the spent fuel and the necessity to consume the ex-weapons plutonium. An irradiation test in the Halden reactor was launched by the OECD Halden Reactor Project (HRP) to investigate the in-pile behavior of plutonium-embedded fuel as a form of mixed oxide (MOX) and of inert matrix fuel (IMF). The first cycle of irradiation was successfully accomplished with good integrity of test fuel rods and without any undesirable fault of instrumentations. The test results revealed that the MOX fuel is more stable under irradiation environments than IMF. In addition, MOX fuel shows lower thermal resistance due to its better thermal conductivity than IMF. The on-line measured in-pile performance data of attrition milled MOX fuel are used in the analysis of the in-pile performance of the fuel with the fuel performance code, COSMOS. The COSMOS code has been developed for the analysis of MOX fuel as well as $UO_2$ fuel up to high burnup and showed good capability to analyze the in-reactor behavior of MOX fuel even with different instrumentation.

• 한국군사과학기술학회지
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• 제22권1호
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• pp.141-149
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• 2019

This study analyzed upper-air temperatures in order to make temperature conditions for weapon system operating in Korean Peninsula. One of important tasks of environmental analysis is to set-up suitable temperature conditions for successful development of weapon system. Many weapon system developers are setting air temperature conditions based on the MIL-STD-810G. However, for weapons systems that are used only in the upper-air of the Korean Peninsula, the air temperature conditions recommended by MIL-STD-810G are often not suitable. To establish the air temperature conditions for upper-air in the Korean Peninsula, the method of Percentage of Occurrence should has be built up as method of temperature analysis. Upper-air climate data of the Korea Peninsulas over the past decade is also analyzed based on this method. The study suggest upper-air temperature conditions for weapons systems that are operated only in the Korean peninsula.

• 한국군사과학기술학회지
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• 제21권6호
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• pp.886-893
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• 2018

U.S. and the allies attacked chemical weapons sites in Syria in 2018, and verbal battles are carried out about the effectiveness of the air strike. Syria claimed 13 missiles were shot down, and Russia claimed 71 missiles were shot down while the U.S. released pictures of completely destroyed targets, only. It led controversy about the effectiveness of missile defense system. If there is a method to observe mission success rate of the air strike, it can not only improve combat awareness but also can be a good sales strategy in military industry. This paper describes effects and considerations of a Weapon Data Link(WDL) technology which can be used as a smoking gun of effectiveness. The paper describes WDL abilities such as In-Flight Track Update, Loiter, and Bomb Hit Indication etc., and presents examples of expected effectiveness of the WDL. In addition, this paper briefly summarizes operational consideration for better performance.

• Nuclear Engineering and Technology
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• 제51권5호
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• pp.1355-1364
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• 2019

A recently published nuclear forensics methodology for source discrimination of separated weapons-grade plutonium utilizes intra-element isotope ratios and a maximum likelihood formulation to identify the most likely source reactor-type, fuel burnup and time since irradiation of unknown material. Sensitivity studies performed here on the effects of random measurement error and the uncertainty in intra-element isotope ratio values show that different intra-element isotope ratios have disproportionate contributions to the determination of the reactor parameters. The methodology is robust to individual errors in measured intra-element isotope ratio values and even more so for uniform systematic errors due to competing effects on the predictions from the selected intra-element isotope ratios suite. For a unique sample-model pair, simulation uncertainties of up to 28% are acceptable without impeding successful source-reactor discrimination. However, for a generic sample with multiple plausible sources within the reactor library, uncertainties of 7% or less may be required. The results confirm the critical role of accurate reactor core physics, fuel burnup simulations and experimental measurements in the proposed methodology where increased simulation uncertainty is found to significantly affect the capability to discriminate between the reactors in the library.

• 방사성폐기물학회지
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• 제19권4호
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• pp.479-489
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• 2021

The Republic of Korea is expected to participate in the denuclearization verification activities by the International Atomic Energy Agency (IAEA) in case any neighboring countries declared denuclearization. In this study, samples for the verification of nuclear activities in undeclared areas were selected for the denuclearization of neighboring countries, and the appropriateness of the procedures was considered. If a country with nuclear weapons declares denuclearization, it must be accompanied by the IAEA's verification regarding nuclear materials and weapons in the declared and undeclared areas. The analysis of the process samples or on-site environmental samples and the verification of undeclared nuclear facilities and materials aid in uncovering any evidence of concealment of nuclear activity in undeclared areas. Therefore, a methodology was established for effective sampling and analysis in accordance with proper procedures. Preparations for sampling in undeclared areas were undertaken for various potential scenarios, such as, the establishment of zones according to radiation dose, methods of supplying electricity, wireless communication networks, targets of sampling according to characteristics of nuclides, manned sampling method, and unmanned sampling method. Through this, procedures were established for pre- and post-site settings in preparation for hazards and limiting factors at nuclear inspection sites.