• Title/Summary/Keyword: Defense response

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Reduction of the Vibration Transmissibility for the Sea-Water Conveying Pipe in a Ship According to its Mount Shape (마운트 형상에 따른 선박용 해수 이송 배관의 진동 전달률 감소)

  • Han, Hyung-Suk;Jeong, Weui-Bong;Cha, Young-Ju
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.6
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    • pp.688-694
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    • 2008
  • The reduction of the structure-borne noise is very important in order to reduce the noise of a ship. The noise at the high frequency range usually comes from the fluid flowing. The noise from the sea-water conveying pipe is one of the main source on these high frequency range. Therefore, the transmissibility variations are evaluated according to the shape of the rubber mount. The evaluations are performed with the frequency response function numerically and experimentally.

A Study of Sound Insulation and Structure Safety of the Shelter from the Firing of the Large Caliber Gun (포 발사에 따른 쉘터 구조물의 차음 및 구조안전성 연구)

  • Lee, HaeSuk;Heo, DongEun;Park, NoSeok;Na, TaeHeum;Jang, YoHan;Hong, JunHee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.639-646
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    • 2017
  • This paper describes the sound insulation and structural safety of the shelter which may be used for shooters. The noise level of the shelter should be less than 100 dB on the basis of the Industrial Safety and Act, the World Health Organization and the MIL-STD. The sound insulation design was designed for the shelter structure. The designed shelter performance was verified by the real measurement after completing the construction of the shelter. The system was also designed using the finite element method with data of sound pressure measured in the test. Its response was obtained numerically. It is proved that the shelter structure is sufficiently safe considering the calculated maximum stress level with the allowable stress of structural property.

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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Analysis of the Acoustic Radiation Efficiency on Multi-excitation System with Different Phase (위상차를 갖는 다중 가진 시 구조물의 방사효율 특성 해석)

  • Kang, Myunghwan;Yi, Jongju;Han, Seungjin;Bae, Sooryong;Jung, Woojin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.12
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    • pp.992-998
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    • 2014
  • Acoustic radiation efficiency is one of the important factors in the prediction of underwater radiated noise of ships. A ship has much equipment to operate successful mission in a ship. Most of equipment is running simultaneously as multi-excitation and becomes the source of underwater radiated noise. In many cases of multi-excitation, phase difference between multi-excitation is not considered. Because vibration response under multi-excitation is the vector sum of each single excitation, acoustic radiation efficiency based on surface velocity field can be affected by phase of excitation. In this study, acoustic radiation efficiency of a plate on air and a stiffened cylindrical model in water under multi-excitation with phase difference is investigated.

Design and Evaluation of INS Initial Alignment under Vibration Environment of Aircraft Run-up (항공기 Run-Up 진동 환경에서의 관성항법장치 초기 정렬 방법 설계 및 평가)

  • Yu, Haesung;Lee, Inseop;Oh, JuHyun;Kim, CheonJoong;Park, Heung-won
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.7
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    • pp.691-698
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    • 2015
  • Inertial Navigation Systems (INS) are widely used as the main navigation device for aircraft. To get the initial attitude, the INS requires the initial alignment before navigation starts. An aircraft also needs an engine test procedure that causes some vibrations before flight. An INS can't be aligned in a vibration environment so the initial alignment is performed before the aircraft engine test. Therefore, the initial alignment time of an INS has been a major factor in limiting an aircraft's takeoff response time. In this paper, we designed an initial alignment algorithm that can be executed even in disturbances such as aircraft run-up. We demonstrated verification of the algorithm that is embedded on the real INS and testing methods to evaluate the alignment of the INS. We also analyzed the test results of the proposed initial alignment algorithm that is performed during a real aircraft run-up.

The Plant-Stress Metabolites, Hexanoic Aacid and Melatonin, Are Potential "Vaccines" for Plant Health Promotion

  • Anderson, Anne J.;Kim, Young Cheol
    • The Plant Pathology Journal
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    • v.37 no.5
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    • pp.415-427
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    • 2021
  • A plethora of compounds stimulate protective mechanisms in plants against microbial pathogens and abiotic stresses. Some defense activators are synthetic compounds and trigger responses only in certain protective pathways, such as activation of defenses under regulation by the plant regulator, salicylic acid (SA). This review discusses the potential of naturally occurring plant metabolites as primers for defense responses in the plant. The production of the metabolites, hexanoic acid and melatonin, in plants means they are consumed when plants are eaten as foods. Both metabolites prime stronger and more rapid activation of plant defense upon subsequent stress. Because these metabolites trigger protective measures in the plant they can be considered as "vaccines" to promote plant vigor. Hexanoic acid and melatonin instigate systemic changes in plant metabolism associated with both of the major defense pathways, those regulated by SA- and jasmonic acid (JA). These two pathways are well studied because of their induction by different microbial triggers: necrosis-causing microbial pathogens induce the SA pathway whereas colonization by beneficial microbes stimulates the JA pathway. The plant's responses to the two metabolites, however, are not identical with a major difference being a characterized growth response with melatonin but not hexanoic acid. As primers for plant defense, hexanoic acid and melatonin have the potential to be successfully integrated into vaccination-like strategies to protect plants against diseases and abiotic stresses that do not involve man-made chemicals.

Development Direction of Defense Weapon System for the 4th Industrial Revolution (4차 산업혁명 대응을 위한 국방 무기체계 개발 발전방향)

  • Kim, Sang-Hun;Chey, Seung-Woo;Hong, Sung-pyo
    • Journal of the Korean Society of Industry Convergence
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    • v.22 no.2
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    • pp.71-79
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    • 2019
  • Since the announcement of President Klaus Schwab's fourth industrial revolution at the World Economic Forum in Davos, Switzerland in January 2016, the fourth industrial revolution has emerged as a hot topic in our society. The United States, Japan, China, and Germany, which are major advanced nations, are preparing and implementing a strategy and system for responding to the Fourth Industrial Revolution, focusing on information and communication technology (ICT) and manufacturing convergence in response to the fourth industrial revolution era. Korea is announcing the expansion of financial support for R & D investment budget and related industries for major technology related to revolution. In this paper, we analyze the defense R & D project procedure of the Defense Improvement Project, which is responsible for the development of the defense weapon system, and present the development direction of the defense weapon system in accordance with the 4th world industrial revolution trend.

Functional Characterization of PR-1 Protein, β-1,3-Glucanase and Chitinase Genes During Defense Response to Biotic and Abiotic Stresses in Capsicum annuum

  • Hong, Jeum-Kyu;Hwang, Byung-Kook
    • The Plant Pathology Journal
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    • v.21 no.3
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    • pp.195-206
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    • 2005
  • Spatial and temporal expression of pathogenesis-related (PR) gene and proteins has been recognized as inducible defense response in pepper plants. Gene expression and/or protein accumulation of PR-1, $\beta-1,3-glucanase$ and chitinase was predominantly found in pepper plants during the inoculations by Xanthomonas campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum coccodes. PR-1 and chitinase genes were also induced in pepper plants in response to environmental stresses, such as high salinity and drought. PR-1 and chitinase gene expressions by biotic and abiotic stresses were regulated by their own promoter regions containing several stress-related cis-acting elements. Overexpression of pepper PR-1 or chitinase genes in heterogeneous transgenic plants showed enhanced disease resistance as well as environmental stress tolerances. In this review, we focused on the putative function of pepper PR-1, $\beta-1,3-glucanase$ and chitinase proteins and/or genes at the biochemical, molecular and cytological aspects.

A Study on Effective Correction of Internal Drag and Wall Interference Using Response Surface in Wind Tunnel Test (풍동시험에서 반응면을 이용한 내부 항력 및 벽면 효과의 효율적 보정방안 연구)

  • Kim, Junemo;Lee, Yeongbin
    • Journal of the Korea Institute of Military Science and Technology
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    • v.22 no.5
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    • pp.637-643
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    • 2019
  • Wind tunnel testing for flow-through model is necessary for performance prediction of an aircraft with air-breathing jet engine. Internal drag correction and wall correction are performed to acquire preciser wind tunnel test data. Many test runs are generally required to correct internal drag and wall interference in wind tunnel test. In this study we investigated more effective correction schemes using the response surface method. Even though the number of tests required for these schemes was much smaller than that for conventional methods, the differences between corrections using these schemes and conventional methods were similar level with the uncertainty of measurement except for the data near the boundaries.