• Title/Summary/Keyword: u-Army

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PARALLEL CFD SIMULATIONS OF PROJECTILE FLOW FIELDS WITH MICROJETS

  • Sahu Jubaraj;Heavey Karen R.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.05a
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    • pp.94-99
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    • 2006
  • As part of a Department of Defense Grand Challenge Project, advanced high performance computing (HPC) time-accurate computational fluid dynamics (CFD) techniques have been developed and applied to a new area of aerodynamic research on microjets for control of small and medium caliber projectiles. This paper describes a computational study undertaken to determine the aerodynamic effect of flow control in the afterbody regions of spin-stabilyzed projectiles at subsonic and low transonic speeds using an advanced scalable unstructured flow solver in various parallel computers such as the IBM SP4 and Linux Cluster. High efficiency is achieved for both steady and time-accurate unsteady flow field simulations using advanced scalable Navier-Stokes computational techniques. Results relating to the code's portability and its performance on the Linux clusters are also addressed. Numerical simulations with the unsteady microjets show the jets to substantially alter the flow field both near the jet and the base region of the projectile that in turn affects the forces and moments even at zero degree angle of attack. The results have shown the potential of HPC CFD simulations on parallel machines to provide to provide insight into the jet interaction flow fields leading to improve designs.

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Security threats and countermeasure of RFID on the "U-Defense" ("U-Defense"에서의 RFID 보안위협과 대책)

  • Jang, Gong-Soo;Lee, Hong-Jin;Yun, Joo-Seung;Park, Yong-Soo
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06d
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    • pp.5-9
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    • 2008
  • 최근 RFID(Radio Frequency Identification)이 기술의 비약적인 발전과 확산으로 관심이 집중되고 있으며, 특히 군에서는 RFID를 활용하여 탄약관리체계, 공군 F-15K 자산관리체계 시범사업을 실시한 바 있고, 2007년부터는 국방부와 정보통신부 협약에 의해 U-Defense 구현의 일환으로 U-Army 실험사업을 추진 중에 있다. 이처럼 군에서 RFID 기술은 다양한 분야에서 활용된다. 그러나 최근 연구에서 RFID가 공격에 취약한 것으로 증명되었다. 이 논문에서는 군에서의 RFID 활용사례와 RFID 공격방법과 대책, 그리고 군에서 RFID 기술을 활용함에 있어 적 위험분석과 대책을 설명한다. 논문의 목적은 U-Defense 구현의 핵심인 RFID 기술의 적 위협들을 인식하고 대응책을 제시하기 위함이다.

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Effect of Fabrication Methods on Static Strength of Polymer Based Composites under the Low Temperature Range (적층 방법에 따른 복합재의 저온 영역 하에서 정적 강도 변화)

  • Eom, Su-Hyeon;Dutta, Piyush K.;Gwon, Sun-Cheol;Kim, Guk-Jin;Kim, Yun-Hae
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.7-12
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    • 2003
  • When the wind turbine is used in cold regions, the mechanical properties and dimension stability of the blade will be changed. The proposal of this paper is to test the durability of the blade for wind turbine. It is necessary to select the most comfortable materials and fabrication processes for more stable wind turbine blade in cold regions. To select the most comfortable materials and processes, the static strength has to know through the tensile static tests at the severe condition as cold regions. First, the tensile static specimens made by RIM (Resin injection molding) process & vacuum bagging process with reinforcement materials and resin. Tensile static tests were carried out on three laminate lay-ups (carbon prepreg, carbon fiber dry fabric and glass fiber dry fabric) at different test temperature($24^{\circ}$, $-30^{\circ}$), determining properties such as the mechanical strength, stiffness and strain to failure. At different test temperature, in order to test the tensile strengths of these specimens used the low temperature chamber. Next, the results of this test were compared with each other. Finally, the most comfortable materials and fabrication processes can select based on these results. The results show the changes in the static behavior of three laminate lay-ups at different test temperatures. At low temperatures, the static strengths are higher than the ones at room temperature.

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A Study on The Korean Climatic Condition for The Military Environmental Testing Specification. (군 환경시험규격 현실화를 위한 한반도 자연환경 조건분석)

  • 이관훈;송병석;홍원식;강보철;염대원;이도희;김준원;금종주
    • Journal of the Korea Institute of Military Science and Technology
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    • v.4 no.2
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    • pp.70-83
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    • 2001
  • The required standards for environmental tests for communication and electronic equipment used currently in the army are not standards into which the Korean climate and use environment are taken into consideration. But the environmental testing standards of the U.S. army at the time of its establishment(MIL-STD-810) “A” version has been used without taking into consideration the Korean domestic situation and conditions by simply translating the US standards. Adherence to these standards may limit the ability to supply materials in case of emergency since the increase in the manufacturing costs according to excessively strict standards induces an increase in the acquisition cost of military equipment, unnecessarily high maintenance and repair expenses are consumed, and stocks of parts for the military use have to be retained at all times.

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Stochastic Analysis to Characterize A CARMONETTE Data

  • Lee Jae-Yeong;Kolding James C.
    • Journal of the military operations research society of Korea
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    • v.15 no.1
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    • pp.78-94
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    • 1989
  • Events that occur within a high 'resolution' combat model often need to be characterized and structured for representation in other models or for detailed analysis purposes. This paper attempts to characterize one of these events, helicopter deaths. The data analyzed for this paper were generated by a high resolution production simulation system, CARMONETTE. The thesis objective is to develop a model to characterize the event of interest, and check the fit of the developed model using a second set of data. The exponential model developed provides not only excellent characterization of Blue helicopter attrition but also sufficient confidence in our results for the purpose of aggregated combat simulation.

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A Study on Defense Information Security Management Structure for Digital Information Warfare (디지털 정보전에 대비한 국방정보보호업무 관리구조에 관한 연구)

  • Kwon, Moon-Taek
    • Convergence Security Journal
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    • v.8 no.4
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    • pp.57-63
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    • 2008
  • The purpose of the research is to intended to help Korean military officers establish information system security structure. Information security is a critical issue for digital information warfare. Advanced countries such as U.S. and Japan have developed a new military security strategy for future information warfare. The readiness of Korean Army, however, is far behind those countries. This paper provides a systematic information security structure for Korean Army, which is a result of the research through a group decision making process.

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User-interface Considerations for the Main Button Layout of the Tactical Computer for Korea Army (한국군 전술컴퓨터의 인간공학적 메인버튼 설계)

  • Baek, Seung-Chang;Jung, Eui-S.;Park, Sung-Joon
    • Journal of the Ergonomics Society of Korea
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    • v.28 no.4
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    • pp.147-154
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    • 2009
  • The tactical computer is currently being developed and installed in armored vehicles and tanks for reinforcement. With the tactical computer, Korea Army will be able to grasp the deployment status of our forces, enemy, and obstacles under varying situations. Furthermore, it makes the exchange of command and tactical intelligence possible. Recent studies showed that the task performance is greatly affected by the user interface. The U.S. Army is now conducting user-centered evaluation tests based on C2 (Command & Control) to develop tactical intelligence machinery and tools. This study aims to classify and regroup subordinate menu functions according to the user-centered task performance for the Korea Army's tactical computer. Also, the research suggests an ergonomically sound layout and size of main touch buttons by considering human factors guidelines for button design. To achieve this goal, eight hierarchical subordinate menu functions are initially drawn through clustering analysis and then each group of menu functions was renamed. Based on the suggested menu structure, new location and size of the buttons were tested in terms of response time, number of error, and subjective preference by comparing them to existing ones. The result showed that the best performance was obtained when the number of buttons or functions was eight to conduct tactical missions. Also, the improved button size and location were suggested through the experiment. It was found in addition that the location and size of the buttons had interactions regarding the user's preference.

A Case Study of Multicultural Applications of World Military Powers (세계 강군의 다문화 적용사례 연구)

  • Kim, In Chan;Cho, Sang Keun;Kim, Jong Hoon;Hong, Myung Sook;Bang, Dong Hyup;Park, Sang Hyuk
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.6
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    • pp.441-447
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    • 2022
  • The Republic of Korea Army predicted that the continuous decline in fertility rate and the low birth rate, one of the biggest issues in our society, would lead to a security crisis due to a lack of military personnel, and revised the Military Service Act in 2010 to prevent enlistment of 'clearly mixed races', which had previously restricted enlistment. made it compulsory As a result, 50 children from multicultural families enlisted in the military in 2011, and the Military Manpower Administration at the time predicted that more than 8,000 people would enlist every year after 2020. This poses another challenge for the Army. A lack of understanding and respect for different languages, religions, and eating habits can lead to conflict among members, which will lead to weakening of combat power. Therefore, through a case study of multicultural application by world powers, the history of success and failure of respect for multiculturalism and the current policy of respecting multiculturalism of the U.S. Army are studied to examine the direction of our army.

The Future War in the 21st Century and the Groundwork for the Korean Style Military Thought (21세기 미래전과 한국적 군사사상 형성의 조건)

  • Kim, Kwang-Soo
    • Journal of National Security and Military Science
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    • s.7
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    • pp.55-89
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    • 2009
  • This article aims to critically review recent U. S. RMA-centered theories of warfare having prevailed after the 1991-92 Gulf War upon which the current ROKA military transformation project, the Vision 2020, largely based. In order to evaluate validity as a universal warfighing theory of NCW (Network Centric Warfare) and EBO (Effects-Based Operations), this article reviews the intrinsic strength and weakness of the theories as well as results of several recent wars that the U. S. Army conducted based on doctrines derived form such theories, In addition, this article examines the impact of certain military technology or weapon system in some well-known historical wars to draw lessons regarding the relationship between technology(weapon system) and military victory. Historical examples has shown that victories in war were not achieved by new technologies alone in most cases. Rather military victories tended to owe to combination of new technology, original doctrine and well conceived organization. Although the U. S. Armed Forces showed brilliant records of operational successes anchored on the system of PGMs and NCW concepts in Iraq (1991-92; 2003) and Afghanistan (2001-02), it must be pointed out that the operational successes did not bring about political ones in cases of Iraq and Afghanistan. It reminds us of perils of too technologically tilted approach to the conduct of war. In sum, one ought to recognize that superior technology nowadays became a necessary condition of success but is not yet a sufficient condition, the ROKA needs to be abreast with development trends of military technologies and related theoretical concepts, it need not too be in a hurry in adopting cutting edged war-making technologies at the expense of large amount of budget. The essay recommends for the ROKA several basic requirements for coping with conduct of future wars as well as establishing a 'Korean style military thought'; (1) Recognition of importance of technology in conduct of war; (2) Imposition of officer self-study hours in working days; (3) Establishing a lifestyle of military professionalism in the Korean officer corps; (4) Setting up small or large groups of think-tanks that are specialized in army doctrinal formulation.

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Study of 4-Nitroazoxybenzenes (Part Ⅰ) Separation of the Isomers of 4-Nitroazoxybenzenes and their Structure Study by U.V. Spectrophotometry (4-Nitroazoxybenzene 에 關한 硏究 (第1報) 4-Nitroazoxybenzene 의 $\{alpha}$- 및 ${\beta}$- 異性體의 分離와 U.V. Spectrophotometry에 의한 그 構造硏究)

  • Chi Sun Hahn;Byung Hi Yun;Hyuk Koo Lee
    • Journal of the Korean Chemical Society
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    • v.7 no.3
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    • pp.197-202
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    • 1963
  • The ${\alpha}-and\;{\beta}$-isomer of 4-nitroazoxybenzenes have been separated by liquid chromatography and their U.V. spectra were examined. The n${\to}{\pi}^{\ast}$ transition band of the compounds did not appear, likewise the cases of other compounds of the series. Transition band of the new isomer were as usual as those of other azoxy-compounds, whereas the ${\pi}{\to}{\pi}^{\ast}$ transition band of the other isomer which is reported in the literature shown peculier hypochromic shift and hypochromic effect. From the spectroscopic point of view it is very likely that the new isomer (m.p. $184-5^{\circ}C$) is ${\alpha}$-isomer and the other one (m.p. $152^{circ}C$) is ${\beta}$-isomer contrary to the literature.

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