• 제목/요약/키워드: Consistent

검색결과 9,954건 처리시간 0.042초

Nondestructive Characterization of Materials Using Laser-Generated Ultrasound

  • Park, Sang-Woo;Lee, Joon-Hyun
    • International Journal of Reliability and Applications
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    • 제5권1호
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    • pp.1-13
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    • 2004
  • It is recently well recognized that the technique for the one-sided stress wave velocity measurement in structural materials provides measurement in structural materials provides valuable information on the state of the material such as quality, uniformity, location of cracked or damaged area. This technique is especially effective to measure velocities of longitudinal and Rayleigh waves when access to only one surface of structure is possible. However, one of problems for one-sided stress wave velocity measurement is to get consistent and reliable source for the generation of elastic wave. In this study, the laser based surface elastic wave was used to provide consistent and reliable source for the generation of elastic wave into the materials. The velocities of creeping wave and Rayleigh wave in materials were measured by the one-sided technique using laser based surface elastic wave. These wave velocities were compared with bulk wave velocities such as longitudinal wave and shear wave velocities to certify accuracy of measurement. In addition, the mechanical properties such as poisson's ratio and specific modulus(E/p) were calculated with the velocities of surface elastic waves.

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Diffusive Shock Acceleration with Self-Consistent Injection

  • KANG HYESUNG
    • 천문학회지
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    • 제34권4호
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    • pp.293-295
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    • 2001
  • A numerical scheme that incorporates a self-consistent cosmic-ray (CR, hereafter) injection model into the combined gas dynamics and CR diffusion-convection code has been developed. The hydro/CR code can follow in a very cos-effective way the evolution of CR modified shocks by adopting subzone shock-tracking and multi-level Adaptive Mesh Refinement techniques. The injection model is based on interactions of the suprathermal particles with self-generated MHD waves in quasi-parallel shocks. The particle injection is followed numerically by filtering the diffusive flux of suprathermal particles across the shock to upstream region according to a velocity-dependent transparency function, which represents the fraction of leaking suprathermal particles. In the strong shock limit of Mach numbers $\ge$20, significant physical processes such as the injection and acceleration seem to become independent of M, while they are sensitively dependent on M for M < 10. Although some particles injected early in the evolution continue to be accelerated to higher energies, the postshock CR pressure reaches a time asymptotic value due to balance between acceleration and diffusion of the CR particles.

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서브미크론 MESFET의 DC 특성 (The DC Characteristics of Submicron MESFEFs)

  • 임행상;손일두;홍순석
    • E2M - 전기 전자와 첨단 소재
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    • 제10권10호
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    • pp.1000-1004
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    • 1997
  • In this paper the current-voltage characteristics of a submicron GaAs MESFET is simulated by using the self-consistent ensemble Monte Carlo method. The numerical algorithm employed in solving the two-dimensional Poisson equation is the successive over-relaxation(SOR) method. The total number of employed superparticles is about 1000 and the field adjusting time is 10fs. To obtain the steady-state results the simulation is performed for 10ps at each bias condition. The simulation results show the average electron velocity is modified by the gate voltage.

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The Study on Inconsistent Rule Based Fuzzy Logic Control using Neural Network

  • Cho, Jae-Soo;Park, Dong-Jo;Z. Bien
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1997년도 춘계학술대회 학술발표 논문집
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    • pp.145-150
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    • 1997
  • In this paper is studied a method of fuzzy logic control based on possibly inconsistent if-then rules representing uncertain knowledge or imprecise data. In most cases of practical applications adopting fuzzy if-then rule bases, inconsistent rules have been considered as ill-defined rules and, thus, not allowed to be in the same rule base. Note, however, that, in representing uncertain knowledge by using fuzzy if-then rules, the knowledge sometimes can not be represented in literally consistent if-then rules. In this regard, when it is hard to obtain consistent rule base, we propose the weighted rule base fuzzy logic control depending on output performance using neural network and we will derive the weight update algorithm. Computer simulations show the proposed method has good performance to deal with the inconsistent rule base fuzzy logic control. And we discuss the real application problems.

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On testing NBUL aging class of life distribution

  • Hassan, M.Kh.;El-Din, M.M. Mohie;Abu-Youssef, S.E.
    • International Journal of Reliability and Applications
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    • 제15권1호
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    • pp.1-9
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    • 2014
  • Let X and $X_t$ denote the lifetime and the residual life at age t, respectively. X is said to be a NBUL (new better than used in Laplace transform order) random variable if $X_t$ is smaller than X in Laplace order, i.e., $X_t{\leq}_{LT}X$. We propose a new test statistics for testing exponentiality versus NBUL class of life distribution. The tests by Hollender and Proschan (1975) and the generalized Hollender and Proschan test by Ains and Mitra (2011) are considered as special cases of the our of test statistics. Our proposed test statistics is simple, consistent and asymptotically normal. Efficiency and powers of the test statistics for some commonly used distributions in reliability are discussed. Finally, real examples are presented to illustrate the theoretical results.

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지상부 노화별 인삼의 엽과 근의 광합성 및 호흡 (Photosynthesis and Respiration of Ginseng Leaf and Root in Relation to Senescence of Aerial Part)

  • 박훈;이명구;이종률
    • Journal of Ginseng Research
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    • 제10권2호
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    • pp.180-186
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    • 1986
  • Photosynthesis and respiration of leaf and root of field grown Panax ginseng were investigated according to aerial part sensecence. No apparent photosynthesis activity was detected in senescenced leaf(less than 0.7mg total chlorophyll/g FW) and leaf dark respiration was consistent relation with senescence. Leaf respiratory Q$_{10}$ consistently increased with senscence. Root respiration and Q$_{10}$ tended to decrease with aerial part senescence only in the range of optimum temperature of leaf growth. Apparent photosynthesis or respiration of leaf was negatively or positively correlated, respectively with the increase of air temperature. Root respiration with temperature was well accordance with Arrhenius plot which was not consistent with aerial part senescence. Accelerated senescence may be recommendable for better root yield unless any reserve in stem or leaves contributes to root through translocation.

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기업의 연구개발투자 결정요인분석 -시장구조 및 재무적 요인을 중심으로- (The Determinant of Investment in Research and Development Analyze - on its Market Structure and Financial Factor -)

  • 황은정
    • 경영과정보연구
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    • 제21권
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    • pp.239-269
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    • 2007
  • The purpose of this thesis is to analyze empirically the relationship between market structure, measured by Herfindahl-Hershmann Index(HHI), and financial factors, and innovation in Korean industry panel datasets for 2000-2006. Results show that debt ratio and scale of the firm has a consistent positive effect on the investment in research and development. As more scale of the firm is getting bigger, the investment in R&D decrease. Also, as more debt ratio of firm rise, the investment for innovation increase. Concentration ratio, the HHI and the classification factor of High-tech industry and Low-tech industry has a consistent positive effect on the innovation. Factors affecting the investment in research and development include market structure and characteristics of industry as well as the internal affairs of the firm.

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로터-베어링 시스템의 훨링속도 해석을 위한 유한요소 정식화 (Finite Element Formulations of the Rotor-Bearing System for Whirl Speed Analysis)

  • 윤성호
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.625-630
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    • 2007
  • This paper accounts for derivations and formulations of the finite element dynamic equation of the rotor-bearing system to analyze its whirling speed. It turns out to be a different form from previous researcher's because of different successive sequences of Euler angles. Correspondingly the adoption of other rotation tensor will be needed for a consistent derivation of the dynamic equation. The process of its finite element formulation with consistent mass matrix and gyroscopic matrix involves a general definition of the modal analysis or the Eigen analysis for the damped system in the inertial frame and rotating frame, respectively.

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Accurate Formulas for Frequency-Dependent Resistance and Inductance Per Unit Length of On-Chip Interconnects on Lossy Silicon Substrate

  • Ymeri, H.;Nauwelaers, B.;Maex, K.;Roest, D.De;Vandenberghe, S.;Stucchi, M.
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제2권1호
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    • pp.1-6
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    • 2002
  • A new closed-form expressions to calculate frequency-dependent distributed inductance and the associated distributed series resistance of single interconnect on a lossy silicon substrate (CMOS technology) are presented. The proposed analytic model for series impedance is based on a self-consistent field method and the vector magnetic potential equation. It is shown that the calculated frequency-dependent distributed inductance and the associated resistance are in good agreement with the results obtained from rigorous full wave solutions and CAD-oriented equivalent-circuit modeling approach.

Kinetics and Mechanism of the Aminolysis of Aryl N-Benzyl Thiocarbamates in Acetonitrile

  • Oh, Hyuck-Keun
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.137-140
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    • 2011
  • The aminolysis reactions of phenyl N-benzyl thiocarbamate with benzylamines in acetonitrile at $50.0^{\circ}C$ are investigated. The reactions are first order in both the amine and the substrate. Under amine excess, pseudo-first coefficient ($k_{obs}$) are obtained, plot of $k_{obs}$ vs free amine concentration are linear. The signs of ${\rho}_{XZ}$ (< 0) are consistent with concerted mechanism. Moreover, the variations of $\rho_X$ and $\rho_Z$ with respect to the sustituent in the substrate and large ${\rho}_{XZ}$ value indicate that the reactions proceed concerted mechanism. The normal kinetic isotope effects ($k_H/k_D$ = 1.3 ~ 1.5) involving deuterated benzylamine nucleophiles suggest a hydrogen-bonded, four-centered-type transition state. The activation parameters, ${\Delta}H^\ddagger$ and ${\Delta}S^\ddagger$, are consistent with this transition state structure.