• 제목/요약/키워드: critical growth

검색결과 1,773건 처리시간 0.026초

POSSIBILITIES AND LIMITATIONS OF APPLYING SOFTWARE RELIABILITY GROWTH MODELS TO SAFETY-CRITICAL SOFTWARE

  • Kim, Man-Cheol;Jang, Seung-Cheol;Ha, Jae-Joo
    • Nuclear Engineering and Technology
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    • 제39권2호
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    • pp.129-132
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    • 2007
  • It is generally known that software reliability growth models such as the Jelinski-Moranda model and the Goel-Okumoto's non-homogeneous Poisson process (NHPP) model cannot be applied to safety-critical software due to a lack of software failure data. In this paper, by applying two of the most widely known software reliability growth models to sample software failure data, we demonstrate the possibility of using the software reliability growth models to prove the high reliability of safety-critical software. The high sensitivity of a piece of software's reliability to software failure data, as well as a lack of sufficient software failure data, is also identified as a possible limitation when applying the software reliability growth models to safety-critical software.

ON A CLASS OF NONCOOPERATIVE FOURTH-ORDER ELLIPTIC SYSTEMS WITH NONLOCAL TERMS AND CRITICAL GROWTH

  • Chung, Nguyen Thanh
    • 대한수학회지
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    • 제56권5호
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    • pp.1419-1439
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    • 2019
  • In this paper, we consider a class of noncooperative fourth-order elliptic systems involving nonlocal terms and critical growth in a bounded domain. With the help of Limit Index Theory due to Li [32] combined with the concentration compactness principle, we establish the existence of infinitely many solutions for the problem under the suitable conditions on the nonlinearity. Our results significantly complement and improve some recent results on the existence of solutions for fourth-order elliptic equations and Kirchhoff type problems with critical growth.

임계 경사각을 고려한 기계적 체결부 균열의 혼합모드 피로균열성장 거동 (Mixed-Mode Fatigue Crack Growth Behavior of Cracks in Mechanical Joints Considering Critical Inclined Angle)

  • 허성필;양원호;정기현;류명해
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 춘계학술대회논문집A
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    • pp.187-192
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    • 2001
  • Cracks in mechanical joints is generally under mixed-mode and there is the critical inclined angle at which mode I stress intensity factor becomes maximum. In order to evaluate the fatigue life of cracks in mechanical joints, horizontal crack normal to the applied load and located on minimum cross section is major concern but critical inclined crack must also be considered. In this paper mixed-mode fatigue crack growth test is performed for horizontal crack and critical inclined crack in mechanical joints. Fatigue crack growth path is predicted by maximum tangential stress criterion using mode I and mode II stress intensity factors obtained from weight function method, and fatigue crack growth rates of horizontal and inclined crack are compared.

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기계적 체결부 균열의 피로균열성장에 관한 연구 (A Study on the Fatigue Crack Growth of Cracks in Mechanical Joints)

  • 허성필;양원호;정기현
    • 한국자동차공학회논문집
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    • 제10권1호
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    • pp.187-194
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    • 2002
  • It has been reported that cracks in mechanical joints is generally under mixed-mode and there is critical inclined angle at which mode I stress intensity factor becomes maximum. The crack propagates in arbitrary direction and thus the prediction of crack growth path is needed to provide against crack propagation or examine safety. In order to evaluate the fatigue life of cracks in mechanical joints, horizontal crack normal to the applied load and located on minimum cross section is major concern but critical inclined crack must also be considered. In this paper mixed-mode fatigue crack growth test is performed far horizontal crack and critical inclined crack in mechanical joints. Fatigue crack growth path is predicted by maximum tangential stress criterion using stress intensity factor obtained from weight function method, and fatigue crack growth rates of horizontal and inclined crack are compared.

MULTIPLE SOLUTIONS FOR A CLASS OF THE SYSTEMS OF THE CRITICAL GROWTH SUSPENSION BRIDGE EQUATIONS

  • Jung, Tacksun;Choi, Q-Heung
    • Korean Journal of Mathematics
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    • 제16권3호
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    • pp.389-402
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    • 2008
  • We show the existence of at least two solutions for a class of systems of the critical growth nonlinear suspension bridge equations with Dirichlet boundary condition and periodic condition. We first show that the system has a positive solution under suitable conditions, and next show that the system has another solution under the same conditions by the linking arguments.

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MULTIPLICITY RESULTS FOR NONLINEAR SCHRÖDINGER-POISSON SYSTEMS WITH SUBCRITICAL OR CRITICAL GROWTH

  • Guo, Shangjiang;Liu, Zhisu
    • 대한수학회지
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    • 제53권2호
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    • pp.247-262
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    • 2016
  • In this paper, we consider the following $Schr{\ddot{o}}dinger$-Poisson system: $$\{\begin{array}{lll}-{\Delta}u+u+{\lambda}{\phi}u={\mu}f(u)+{\mid}u{\mid}^{p-2}u,\;\text{ in }{\Omega},\\-{\Delta}{\phi}=u^2,\;\text{ in }{\Omega},\\{\phi}=u=0,\;\text{ on }{\partial}{\Omega},\end{array}$$ where ${\Omega}$ is a smooth and bounded domain in $\mathbb{R}^3$, $p{\in}(1,6]$, ${\lambda}$, ${\mu}$ are two parameters and $f:\mathbb{R}{\rightarrow}\mathbb{R}$ is a continuous function. Using some critical point theorems and truncation technique, we obtain three multiplicity results for such a problem with subcritical or critical growth.

급속응고법을 이용한 Bi 계 고온초전도체 전류도입선 제조 (Current Leads Fabrication of High $T_c$ Bi System Superconductor Using Rapid Cooling Method)

  • 박용민;한진만;류운선;류운선
    • 한국전기전자재료학회논문지
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    • 제13권3호
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    • pp.254-258
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    • 2000
  • Current leads of high $T_{c}$ superconductor were fabricated with Bi excess B $i_{2.2}$/S $r_{1.8}$/C $a_{1}$/C $u_{2}$/ $O_{x}$ composition by rapid cooling method. The dimensions of final samples were fixed 3 mm and 8 mm diameter with 50 mm length each To control uniform density the samples were preformed by CIP(Cold Isostatic Press) process and followed by partial or full melting process after raising up to 90$0^{\circ}C$ for 30min. Plate shaped microstructure was clearly observed adjacent to the Ag tube wall and the size of plate was about 100$\mu$m. However the severe destruction of growth orientation was shown in the inner growth part. critical temperature ( $T_{c}$) was about 53~71K after directional growth while Tc was decreased about 77~80 K before directional growth. After directional growth critical current( $I_{c}$) and critical current density( $J_{c}$) in the specimen of 8 mm diameter at 50 K were about 110 A and 280 A/c $m^2$ respectively.pectively.ely.

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