• Title/Summary/Keyword: Defense Research and Development

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An Additional Mechanism for the Cytotoxicity of 2-Chloroethylethyl Sulfide in Spleen Lymphocytes; Lysosomal Labilization

  • Choi, Dae-Sung;Shin, Sung-Ho;Kim, Yun-Bae;Cha, Seung-Hee;Sok, Dai-Eun
    • BMB Reports
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    • v.28 no.1
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    • pp.79-82
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    • 1995
  • Exposure of spleen lymphocytes to 2-chloroethylethyl sulfide (CEES) leads to a reduction of the intracellular ATP level, followed by a decrease in cell viability. Addition of nicotinamide, an inhibitor of poly(ADP-ribose) polymerase (PADPRP), restores both ATP level and viability, indicating that an activation of PADPRP is responsible for the cytotoxicity of CEES. The involvement of a $Ca^{2+}$-mediated process in cytotoxicity is suggested. Verapamil, EGTA, trifluoperazine, and butacaine exhibit a partial protection (20 to 58%) against the cytotoxicity of CEES. Investigation of the causative role of proteolytic degradation in cell death indicate that pepstatin and leupeptin exert a substantial protective effect (60 to 70%), suggesting the involvement of lysosomal destabilization in CEES-induced cytotoxicity. Also, lysosomotropic agents markedly decrease the cytotoxicity. Lysosomal labilization may be a mechanism for the cytotoxicity of CEES.

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Accuracy Improvement of Low Fidelity Solver by Augmentation of Fin Aerodynamic Database (공력 조종면 데이터베이스 확장을 통한 저 충실도 해석자의 정확도 개선)

  • Kang, Eunji;Kim, Younghwa;Yim, Kyungjin;Lee, Jae Eun;Kang, Kyoung-Tai
    • Journal of the Korea Institute of Military Science and Technology
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    • v.25 no.1
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    • pp.45-54
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    • 2022
  • There has been necessity to supplement the fin database to improve the accuracy of low-fidelity aerodynamic solver for missile configuration. In this study, fin database is expanded by in-house solver, utilized in the triservice data the previously established into regions beyond means of CFD. Fin alone data of CFD analysis results in the original region is matched well with triservice data originated from the wind tunnel tests. Extensive fin aerodynamic data from CFD analysis is added to the existing database of the low-fidelity solver. For confirmation, aerodynamic characteristics of body-tail and body-canard-tail missile configurations is computed using upgraded low-fidelity solver at transonic region. The result using improved solver shows good agreements with wind tunnel test and CFD analysis results, which implies that it becomes more accurate.

Simulation for SEAD Mission with MUM-T (SEAD 임무를 위한 유·무인 협업 모의)

  • Sungbeom Jo;Young Mee Choi;Jihyun Oh;Hyunsam Myung;Heungsik Lim
    • Journal of the Korea Institute of Military Science and Technology
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    • v.26 no.5
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    • pp.409-421
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    • 2023
  • In the air power, UAVs have played a large and diversified role in performing missions from simple to high-level complex ones. In particular, the suppression of enemy air defenses(SEAD) is very dangerous for a pilot so it is expected that the manned-unmanned teaming(MUM-T) system with tailless stealthy unmanned aerial vehicle(UAV) will greatly enhance effectiveness of the mission while ensuring the pilot safe. This paper describes simulation studies of remote airborne control(RAC) environment for performing the SEAD mission by MUM-T, by which the air force pilot remotely controls tailless UAVs individually or small UAVs in swarm. Through this simulation, air force pilot can derive the concept of MUM-T mission operation with various UAVs in the future, and it can be used to upgrade the MUM-T system by verifying the effectiveness of the mission.

Adversarial Attacks for Deep Learning-Based Infrared Object Detection (딥러닝 기반 적외선 객체 검출을 위한 적대적 공격 기술 연구)

  • Kim, Hoseong;Hyun, Jaeguk;Yoo, Hyunjung;Kim, Chunho;Jeon, Hyunho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.6
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    • pp.591-601
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    • 2021
  • Recently, infrared object detection(IOD) has been extensively studied due to the rapid growth of deep neural networks(DNN). Adversarial attacks using imperceptible perturbation can dramatically deteriorate the performance of DNN. However, most adversarial attack works are focused on visible image recognition(VIR), and there are few methods for IOD. We propose deep learning-based adversarial attacks for IOD by expanding several state-of-the-art adversarial attacks for VIR. We effectively validate our claim through comprehensive experiments on two challenging IOD datasets, including FLIR and MSOD.

Research on Improving Schedule Forecasting Method for Delayed Defense Research & Development Project (지연된 국방 연구개발 프로젝트의 일정 예측방식 개선 연구)

  • Cho, Jungho;Lim, Jaesung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.3
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    • pp.286-293
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    • 2020
  • Since Dr. Lipke announces earned schedule management(ESM) in 2002, it has been used in project management to make up for the insufficient schedule management function of earned value management technique. However, it is difficult to accurately forecast the schedule of delayed defense research and development(R&D) projects with the ESM technique. Therefore, this paper proposes a new schedule forecasting method considering the progress of delayed work in ESM technique. This concept can also be adopted to the traditional project progress management (PPM) technique. We verify the effectiveness of the proposed concept through several defense R&D projects and prove that it is possible to supplement the schedule forecasting of the ESM and PPM technique.

A Fault-Tolerant Scheme Based on Message Passing for Mission-Critical Computers (임무지향 컴퓨터를 위한 메시지패싱 고장감내 기법)

  • Kim, Taehyon;Bae, Jungil;Shin, Jinbeom;Cho, Kilseok
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.6
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    • pp.762-770
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    • 2015
  • Fault tolerance is a crucial design for a mission-critical computer such as engagement control computer that has to maintain its operation for long mission time. In recent years, software fault-tolerant design is becoming important in terms of cost-effectiveness and high-efficiency. In this paper, we propose MPCMCC which is a model-based software component to implement fault tolerance in mission-critical computers. MPCMCC is a fault tolerance design that synchronizes shared data between two computers by using the one-way message-passing scheme which is easy to use and more stable than the shared memory scheme. In addition, MPCMCC can be easily reused for future work by employing the model based development methodology. We verified the functions of the software component and analyzed its performance in the simulation environment by using two mission-critical computers. The results show that MPCMCC is a suitable software component for fault tolerance in mission-critical computers.

Plant development and defense signal network research

  • Paek, Kyung-Hee
    • Proceedings of the Korean Society of Plant Biotechnology Conference
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    • 2005.11a
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    • pp.81-83
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    • 2005
  • The Plant Signaling Network Research Center (SigNet) is a government-funded (by Korea's Ministry of Science and Technology (MOST)/ Korea Science and Engineering Foundation (KOSEF)) research center established at the School of Life Sciences and Biotechnology of Korea University in 2003. The SigNet conducts plant biological studies, especially in the field of developmental and defense biology. The research purpose of SigNet is dissection and analysis of plant development and defense signaling network through multiscientific approaches. Knowledge acquired from SigNet research scientists will provide new integrated view of understanding and potential application of plant development and defense mechanism. The other important mission of the SigNet is nurturing Center of Excellence for future outstanding research scientists of Korea. The SigNet will continue to expend every effort to achieve the goals for the future. Through passionate research endeavor of each laboratory and partnerships within inside and outside laboratories, we will continue to develop world-leading plant research group and to educate new generations of innovative researchers. As the SigNet looks toward the future, the SigNet will try to achieve its mission of research, education and service to the community. And the defense response research of our lab will be presented at later part.

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Numerical Analysis of the Effect of Fuselage of Fan-in-body Aircraft on the Pusher Propeller

  • Kang, Jiwook;Jang, Jisung;You, Younghyun;Hyun, Youngo;Lee, Jonghun
    • Journal of Aerospace System Engineering
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    • v.15 no.2
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    • pp.26-35
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    • 2021
  • In this study, CFD analysis was conducted to compare the aerodynamic performance of the isolated propeller and pusher propeller, which is affected by the wake of wide fuselage. The moving reference frame (MRF) method was used for isolated propeller analysis, while the MRF and sliding mesh method were used sequentially for the pusher propeller to analyze the change in the aerodynamic characteristics based on the azimuth angle. Under the same torque condition, the thrust of the pusher propeller was greater than that of the isolated propeller. Thrust increment of the pusher propeller was mainly generated near the root of the blade where the fuselage wake was concentrated. The net efficiency of the pusher propeller was greater than or equal to that of the isolated propeller. Because of the flat fuselage shape, thrust and torque of the pusher propeller periodically changed with the rotation of the propeller.

Numerical Study of Ablation Phenomena of Flame Deflector

  • Lee, Wonseok;Yang, Yeongrok;Shin, Sangmok;Shin, Jaecheol
    • Journal of Aerospace System Engineering
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    • v.15 no.6
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    • pp.10-18
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    • 2021
  • A flame deflector prevents a launch system from thermal damage by deflecting the exhaust flame of the launch vehicle. During the deflection of the flame, the flame deflector is subjected to a high-temperature and high-pressure flow, which results in thermal ablation damage at the surface. Predicting this ablation damage is an essential requirement to ensure a reliable design. This paper introduces a numerical method for predicting the ablation damage phenomena based on a one-way fluid-structure interaction (FSI) analysis. In the proposed procedure, the temperature and convective heat transfer coefficient of the exhaust flame are calculated using a fluid dynamics analysis, and then the ablation is calculated using a finite element analysis (FEA) based on the user-subroutine UMESHMOTION and Arbitrary Lagrangian-Eulerian (ALE) adaptive mesh technique in ABAQUS. The result of such an analysis was verified by comparison to the ablation test result for a flame deflector.

Stabilization Performance Test Technique for LAH Turret Driving System (소형무장헬기 회전형 포탑시스템의 안정화추적 성능 시험기법)

  • Nam, Byounguk;Lee, Hojung;Jo, Sihun;Cho, Sunghun
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.6
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    • pp.786-792
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    • 2014
  • In this paper, we propose a novel method which can be applied to test and verify the stabilization-tracking performance of Gun/Turret Driving System(GTDS) for Light Armed Helicopter(LAH). In real system, GTDS is connected to TADS/SMC and drived to aim at the target with 20mm gun. But each equipment is separately developed during exploratory development stage, so GTDS cannot be tested under real system state. We suggest new configuration of test system for evaluating the stabilization-tacking performance, in which TADS and SMC are replaced by vision acquisition unit and processing unit, respectively.