• 제목/요약/키워드: homogeneous function

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A Class of Discrete Time Coverage Growth Functions for Software Reliability Engineering

  • Park, Joong-Yang;Lee, Gye-Min;Park, Jae-Heung
    • Communications for Statistical Applications and Methods
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    • 제14권3호
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    • pp.497-506
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    • 2007
  • Coverage-based NHPP SRGMs have been introduced in order to incorporate the coverage growth behavior into the NHPP SRGMs. The coverage growth function representing the coverage growth behavior during testing is thus an essential factor of the coverage-based NHPP SRGMs. This paper proposes a class of discrete time coverage growth functions and illustrates its application to real data sets.

GENERALIZED STABILITIES OF CAUCHY'S GAMMA-BETA FUNCTIONAL EQUATION

  • Lee, Eun-Hwi;Han, Soon-Yi
    • 호남수학학술지
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    • 제30권3호
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    • pp.567-579
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    • 2008
  • We obtain generalized super stability of Cauchy's gamma-beta functional equation B(x, y) f(x + y) = f(x)f(y), where B(x, y) is the beta function and also generalize the stability in the sense of R. Ger of this equation in the following setting: ${\mid}{\frac{B(x,y)f(x+y)}{f(x)f(y)}}-1{\mid}$ < H(x,y), where H(x,y) is a homogeneous function of dgree p(0 ${\leq}$ p < 1).

균질 지반과 비균질 지반에서 강관 모형말뚝의 수평거동 특성에 관한 모형실험 (Model Tests on the Characteristics of Lateral Behavior of Steel Pipe Pile in Homogeneous and Nonhomogeneous Soil Conditions)

  • 김병탁;김영수
    • 한국지반공학회지:지반
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    • 제14권6호
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    • pp.153-166
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    • 1998
  • 본 논문은 균질 및 비균질 낙동강 사질토 지반에서 수평 및 경사하중을 받은 강관 말뚝의 수평거동에 대한 모형실험 결과들을 고찰하였다. 비균질 지반은 상부와 하부층의 2개층으로 이루졌다. 본 연구의 목적은 말뚝의 수평거동에 대한 경사하중$(Q_\beta)$, 말뚝 근입길이에 대한 하부지반의 높이비 (H/S), 그리고 상.하부지반의 지반반력계수비$(E_{h1}E_{h2})$의 영향에 관하여 실험적인 연구를 수행하고 이러한 영향들을 정량화 할 수 있는 실험결과를 얻었다. 모형실험 결과들에 의하면, 비균질 지반에서 수평거동은 다른 인자들보다 $E_{h1}E_{h2}$에 더 의존하는 것으로 나타났다. 균질지반에 대한 비균질 지반의 수평변위비$(y_{H/L}/y_{H/L=0}$)와 말뚝 근입길이에 대한 하부지반의 높이비(H/L)의 관계는 지수 함수식으로 회귀분석 되었다. 경사하중을 받는 경우의 휨 모멘트-깊이 관계는 수평하중을 받는 말뚝의 경우와 상이하게 나타났으며, 상대밀도 90%에서는 최대 휨모멘트 발생깊이는 수평하중을 받는 경우보다 약 70% 깊어졌다.

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LOCAL STABILITY OF CAUCHY FUNCTIONAL EQUATION

  • Park, Kyoo-Hong;Lee, Young-Whan;Ji, Kyoung-Sihn
    • Journal of applied mathematics & informatics
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    • 제8권2호
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    • pp.581-590
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    • 2001
  • In this paper we prove a local stability of Gavruta’s theorem for the generalized Hyers-Ulam-Rassias Stability of Cauchy functional equation.

A GORENSTEIN IDEAL OF CODIMENSION 4

  • Shin, Yong-Su
    • 대한수학회지
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    • 제34권1호
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    • pp.135-147
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    • 1997
  • Let k be an infinite field and let $X = {P_1, \cdots, P_s}$ be a set of s-distinct points in $P^n$. We denote by $I(X)$ the defining ideal of $X$ in the polynomial ring $R = k[x_0, \cdots, x_n]$ and by A the homogeneous coordinate ring of $X, A = \sum_{t = 0}^{\infty} A_t$.

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급속응고기술에 의한 p-type 25% $Bi_{2}Te_{3}+75% Sb_{2}Te_{3}$ 열간압축제의 열전특성 (Thermoelectric Properties of p-type 25% $Bi_{2}Te_{3}+75%Sb_{2}Te_{3}$ Materials Prepared by Rapid Solidification Process and Hot Pressing)

  • 김익수
    • 한국분말재료학회지
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    • 제3권4호
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    • pp.246-252
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    • 1996
  • $Bi_{2}Te_{3}-Sb_{2}Te_{3}$, $Bi_{2}Te_{3}-Bi_{2}Se_{3}$ solid solutions are of great interest as materials for thermoelectric energy conversion. One of the key technologies to ensure the efficiency of thermoelectric device is to obtain chemically homogeneous solid solutions. In this work, the new process with rapid solidification followed by hot pressing was investigated to produce homogeneous thermoelectric materials. Characteristics of the materials were examined with XRD, SEM, EPMA-line scan and bending test. Property variations of the materials were investigated as a function of variables, such as excess Te quantity and hot pressing temperature. Quenched ribbons are very brittle and consisted of homogeneous $Bi_{2}Te_{3}$, $Sb_{2}Te_{3}$ solid solutions. When the process parameters were optimized, the maximum figure of merit was 3.073$\times$$10^{-3}K^{-4}$. The bending strength of the material, hot pressed at 45$0^{\circ}C$, was 5.87 kgf/${mm}^2$.

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Spectral SFEM analysis of structures with stochastic parameters under stochastic excitation

  • Galal, O.H.;El-Tahan, W.;El-Tawil, M.A.;Mahmoud, A.A.
    • Structural Engineering and Mechanics
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    • 제28권3호
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    • pp.281-294
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    • 2008
  • In this paper, linear elastic isotropic structures under the effects of both stochastic operators and stochastic excitations are studied. The analysis utilizes the spectral stochastic finite elements (SSFEM) with its two main expansions namely; Neumann and Homogeneous Chaos expansions. The random excitation and the random operator fields are assumed to be second order stochastic processes. The formulations are obtained for the system solution of the two dimensional problems of plane strain and plate bending structures under stochastic loading and relevant rigidity using the previously mentioned expansions. Two finite element programs were developed to incorporate such formulations. Two illustrative examples are introduced: the first is a reinforced concrete culvert with stochastic rigidity subjected to a stochastic load where the culvert is modeled as plane strain problem. The second example is a simply supported square reinforced concrete slab subjected to out of plane loading in which the slab flexural rigidity and the applied load are considered stochastic. In each of the two examples, the first two statistical moments of displacement are evaluated using both expansions. The probability density function of the structure response of each problem is obtained using Homogeneous Chaos expansion.