• Title/Summary/Keyword: Survivability

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Size, Shape and Topology Optimum Design of Trusses Using Shape & Topology Genetic Algorithms (Shape & Topology GAs에 의한 트러스의 단면, 형상 및 위상최적설계)

  • Park, Choon-Wook;Yuh, Baeg-Youh;Kim, Su-Won
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.43-52
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    • 2004
  • The objective of this study is the development of size, shape and topology discrete optimum design algorithm which is based on the genetic algorithms. The algorithm can perform both shape and topology optimum designs of trusses. The developed algerian was implemented in a computer program. For the optimum design, the objective function is the weight of trusses and the constraints are stress and displacement. The basic search method for the optimum design is the genetic algorithms. The algorithm is known to be very efficient for the discrete optimization. The genetic algorithm consists of genetic process and evolutionary process. The genetic process selects the next design points based on the survivability of the current design points. The evolutionary process evaluates the survivability of the design points selected from the genetic process. The efficiency and validity of the developed size, shape and topology discrete optimum design algorithms were verified by applying the algorithm to optimum design examples

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A Study on the Management Methods of the Ship Infrared Signature (함정 적외선 신호의 관리방법 연구)

  • Cho, Yong-Jin
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.3
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    • pp.182-189
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    • 2013
  • In the development process of new naval ships, it is necessary to make the effort of the signature management and reduction of ship infrared(IR) signature to increase the ship survivability(susceptibility). So far the ship's contrast radiant intensity is used as a ship IR signature design criteria during the naval ship design stages. However, nowaday it is in a state of disorder at the basic design stage because of the lack of any related studies and methods. In this study, the IR signature management methods for improving the signature reduction and ship survivability are suggested by the comparison analysis of the advantages and disadvantages of signature management techniques. And also the criteria for the ship signature management are suggested when considering the infrared signature measuring assets and sea trial environments of the Korean peninsula.

A new concept for blast hardened bulkheads with attached aluminum foam

  • Kim, Sung-Ho;Woo, Heekyu;Choi, Gul-Gi;Yoon, Kyungho
    • Structural Engineering and Mechanics
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    • v.65 no.3
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    • pp.243-250
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    • 2018
  • The use of blast hardened bulkheads (BHBs) is an effective vulnerability hardening technique for improving the survivability of naval warships when internal explosions occur due to being shot by an anti-surface missile. In this paper, a new concept of BHBs reinforced by aluminum (Al) foam is proposed. The new concept can significantly reduce the blast pressures transferred to bulkheads and, unlike conventional BHBs, can be easily installed to operating naval warships. Chamber model blast tests were performed to demonstrate the effectiveness of the Al-foam BHBs and the results are further supported by numerical simulations. Finally, a practical preliminary is proposed for the Al-foam BHBs.

Discrete Optimum Design of Space Truss Structures Using Genetic Algorithms

  • Park, Choon Wook;Kang, Moon Myung
    • Architectural research
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    • v.4 no.1
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    • pp.33-38
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    • 2002
  • The objective of this study is the development of discrete optimum design algorithms which is based on the genetic algorithms. The developed algorithms was implemented in a computer program. For the optimum design, the objective function is the weight of space trusses structures and the constraints are stresses and displacements. This study solves the problem by introducing the genetic algorithms. The genetic algorithms consists of genetic process and evolutionary process. The genetic process selects the next design points based on the survivability of the current design points. The evolutionary process evaluates the survivability of the design points selected from the genetic process. The efficiency and validity of the developed discrete optimum design algorithms was verified by applying the algorithms to optimum design examples.

The Shock-Test Result and Analysis Using Dual-Pulse Shock Testing Machine (이중충격파형 충격시험장비를 이용한 충격시험 결과 및 분석)

  • Bae, Jongsoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.21 no.3
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    • pp.342-348
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    • 2018
  • The important issue of equipment installed in maritime weapon system is shock survivability against underwater explosion(UNDEX). If the shock survivability of equipment should not be guaranteed, the successful mission also could not be achieved. For that reason, the shock-resistance of each equipment under UNDEX environment should be demonstrated before deployment at combat field. However, the actual UNDEX test on the ocean is too expensive to conduct. Also, it has diverse dangerous factors. The main characteristic of UNDEX is a dual-pulse shock. The vertical shock test machine able to simulate dual pulse shock signal on the ground will be introduced in this paper. The dual-pulse shock signal presented in certain shock standard was achieved with this shock-test machine on the ground. The analytical procedure to set a test condition was verified by comparing simulation result with experiment result.

Isolation and Characterization of Ureolytic Bacteria for Biosequestration of Strontium (스트론튬 격리화를 위한 요소 분해 박테리아의 분리 및 특성 연구)

  • Choi, Jae-Ho;Kang, Chang-Ho;Han, Sang-Hyun;Kwak, Dae Young;Oh, SooJi;So, Jae-Seong
    • KSBB Journal
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    • v.28 no.3
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    • pp.165-169
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    • 2013
  • In this study, 52 ureolytic bacterial strains were newly isolated from various environments. From these, 2 strains (TB-15 and TB-22) were selected based on their high urease activity. XRD spectra clearly showed presence of various sequestration products such as calcite and strontianite in samples. TB-22 showed 20~30% higher survivability upon Sr concentration (20 mM) than Sporosarcina pasteurii KCTC 3558. TB-15 and TB-22 showed 80~90% higher survivability at pH 6 than S. pasteurii. The results demonstrated that the 2 isolates colud be good candidates for the bioremediation of Sr contaminated sites.

Enhancing Network Service Survivability in Large-Scale Failure Scenarios

  • Izaddoost, Alireza;Heydari, Shahram Shah
    • Journal of Communications and Networks
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    • v.16 no.5
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    • pp.534-547
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    • 2014
  • Large-scale failures resulting from natural disasters or intentional attacks are now causing serious concerns for communication network infrastructure, as the impact of large-scale network connection disruptions may cause significant costs for service providers and subscribers. In this paper, we propose a new framework for the analysis and prevention of network service disruptions in large-scale failure scenarios. We build dynamic deterministic and probabilistic models to capture the impact of regional failures as they evolve with time. A probabilistic failure model is proposed based on wave energy behaviour. Then, we develop a novel approach for preventive protection of the network in such probabilistic large-scale failure scenarios. We show that our method significantly improves uninterrupted delivery of data in the network and reduces service disruption times in large-scale regional failure scenarios.

Preliminary Studies on the Role of ${\alpha}-Esterase$ Isozymes in Quantitative Traits of Two Multivoltine Silkworm (Bombyx mori L.) Races and their $F_1$ Hybrid

  • Kumaresan P.;Somasundaram P.;Kumar K. Ashok;Urs S. Raje
    • International Journal of Industrial Entomology and Biomaterials
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    • v.13 no.2
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    • pp.113-117
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    • 2006
  • Heterosis was studied involving two multivoltine silkworm breeds viz, APM1 and SLKSPM through rearing and isozyme analysis. A positive significant heterotic effect was observed in fecundity, hatching % and survivability. The heterobeltiosis was observed only in fecundity and hatching %. Isozyme analysis of ${\alpha}-esterase$ showed variation in loci and allelic expression. The allele with heterozygosity $(Est-2^{12})$ was observed at the Est-2 locus in $F_1$ progeny. Est-3 was observed in $F_1$ progeny, whereas it was completely absent in both parental lines. The present study suggests that the markers ($Est-2^{12}$ and Est-3) targeted for introgression may be useful for the improvement of fecundity and survivability as the phenomenon of heterosis was observed only in $F_1$ progeny.

Shock Traveling Analysis of Truck-Mounted Special Equipments (트럭 탑재 특수 장비의 충격 주행 해석)

  • Song, Oh-Seop;Lee, Hak-Yeol
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.4
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    • pp.381-389
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    • 2010
  • Modern military equipments are often required to be mounted on a truck for their survivability and operation performance. Special units installed on the truck at times experience serious shock vibration caused by obstacles of road and/or uncommon road shape. It is then essential to analyze the travel performance of truck-mounted special units for their survivability and performance. In this paper, shock responses of the equipments subjected to bump passing and wash board road are experimentally obtained and also analyzed via FEM. Modified bump configuration and road profile considering the interface with tire are suggested. Analytical results considering this modification show good agreement with test results.