• 제목/요약/키워드: Moment sequence

검색결과 118건 처리시간 0.025초

ON THE ALMOST SURE CONVERGENCE OF WEIGHTED SUMS OF NA RANDOM VARIABLES

  • Kim, T.S.;Ko, M.H.;Lee, Y.M.;Lin, Z.
    • Journal of the Korean Statistical Society
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    • 제33권1호
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    • pp.99-106
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    • 2004
  • Let {X, $X_{n}, n\;{\geq}\;1$} be a sequence of identically distributed, negatively associated (NA) random variables and assume that $│X│^{r}$, r > 0, has a finite moment generating function. A strong law of large numbers is established for weighted sums of these variables.

움직임에 의한 모양 변화 기술을 위한 모양 시퀀스 기술자 (Shape Sequence Descriptor for Describing Shape Variation by Object Movement)

  • 공영민;최민석;김회율
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.355-358
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    • 2001
  • 본 논문에서는 객체의 움직임에 의한 모양 변화를 표현하기 위하여 MPEG-7 에 제안된 모양 시퀀스 기술자(Shape Sequence Descriptor)에 대하여 설명하고, 모양 시퀀스 기술자 추출에 필요한 Shape Variation Map 생성을 위한 두 가지 방법을 비교하였다. 기존의 방법은 물체의 평균 적인 모양에 가중치를 두어 생성되며, 새로운 방법은 물체의 움직임에 의해 변화되는 부분에 더 가중치를 두는 방법으로 생성된다. 또한 최종적으로 사용되는 특징 값으로 Zernike moment를 이용하는 방법과 ART(Angular Radial Transform)을 이용하는 방법을 비교하여 모양 시퀀스 검색을 위한 가장 효율적인 방법을 제안하였다.

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직접시퀀스 확산대역 시스템의 빠른 포착을 위한 새로운 알고리듬 (A new algorithm for fast acquisition for direct-sequence spread-spectrum systems)

  • 이명환;이재홍
    • 전자공학회논문지A
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    • 제32A권7호
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    • pp.8-15
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    • 1995
  • We have proposed a new fast serial serch algorithm and a receiver for direct-sequence spead-spectrum acquisition systems and analyzed its perfoemance. This algorithm achieves faster acquisition by more than two times that of existing algorithm. We have derived equations of the mean acquistion time by using moment generating function and direct approach, and presented numerical results.

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Effects of near-fault loading and lateral bracing on the behavior of RBS moment connections

  • Yu, Qi-Song Kent;Uang, Chia-Ming
    • Steel and Composite Structures
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    • 제1권1호
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    • pp.145-158
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    • 2001
  • An experimental study was conducted to evaluate the effects of loading sequence and lateral bracing on the behavior of reduced beam section (RBS) steel moment frame connections. Four full-scale moment connections were cyclically tested-two with a standard loading history and the other two with a near-fault loading history. All specimens reached at least 0.03 radian of plastic rotation without brittle fracture of the beam flange groove welds. Two specimens tested with the nearfault loading protocol reached at least 0.05 radian of plastic rotation, and both experienced smaller buckling amplitudes at comparable drift levels. Energy dissipation capacities were insensitive to the types of loading protocol used. Adding a lateral bracing near the RBS region produced a higher plastic rotation; the strength degradation and buckling amplitude were reduced. A non-linear finite element analysis of a one-and-a-half-bay beam-column subassembly was also conducted to study the system restraint effect. The study showed that the axial restraint of the beam could significantly reduce the strength degradation and buckling amplitude at higher deformation levels.

SELF-NORMALIZED WEAK LIMIT THEOREMS FOR A ø-MIXING SEQUENCE

  • Choi, Yong-Kab;Moon, Hee-Jin
    • 대한수학회보
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    • 제47권6호
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    • pp.1139-1153
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    • 2010
  • Let {$X_j,\;j\geq1$} be a strictly stationary $\phi$-mixing sequence of non-degenerate random variables with $EX_1$ = 0. In this paper, we establish a self-normalized weak invariance principle and a central limit theorem for the sequence {$X_j$} under the condition that L(x) := $EX_1^2I{|X_1|{\leq}x}$ is a slowly varying function at $\infty$, without any higher moment conditions.

THE FLAT EXTENSION OF NONSINGULAR EMBRY MOMENT MATRICES E(3)

  • Li, Chunji;Liang, Hongkai
    • 대한수학회논문집
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    • 제35권1호
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    • pp.137-149
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    • 2020
  • Let γ(n) ≡ {γij} (0 ≤ i+j ≤ 2n, |i-j| ≤ n) be a sequence in the complex number set ℂ and let E (n) be the Embry truncated moment matrices corresponding from γ(n). For an odd number n, it is known that γ(n) has a rank E (n)-atomic representing measure if and only if E(n) ≥ 0 and E(n) admits a flat extension E(n + 1). In this paper we suggest a related problem: if E(n) is positive and nonsingular, does E(n) have a flat extension E(n + 1)? and give a negative answer in the case of E(3). And we obtain some necessary conditions for positive and nonsingular matrix E (3), and also its sufficient conditions.

Precise Rates in Complete Moment Convergence for Negatively Associated Sequences

  • Ryu, Dae-Hee
    • Communications for Statistical Applications and Methods
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    • 제16권5호
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    • pp.841-849
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    • 2009
  • Let {$X_n$, n ${\ge}$ 1} be a negatively associated sequence of identically distributed random variables with mean zeros and positive finite variances. Set $S_n$ = ${\Sigma}^n_{i=1}\;X_i$. Suppose that 0 < ${\sigma}^2=EX^2_1+2{\Sigma}^{\infty}_{i=2}\;Cov(X_1,\;X_i)$ < ${\infty}$. We prove that, if $EX^2_1(log^+{\mid}X_1{\mid})^{\delta}$ < ${\infty}$ for any 0< ${\delta}{\le}1$, then $\lim_{{\epsilon}\downarrow0}{\epsilon}^{2{\delta}}\sum_{{n=2}}^{\infty}\frac{(logn)^{\delta-1}}{n^2}ES^2_nI({\mid}S_n{\mid}\geq{\epsilon}{\sigma}\sqrt{nlogn}=\frac{E{\mid}N{\mid}^{2\delta+2}}{\delta}$, where N is the standard normal random variable. We also prove that if $S_n$ is replaced by $M_n=max_{1{\le}k{\le}n}{\mid}S_k{\mid}$ then the precise rate still holds. Some results in Fu and Zhang (2007) are improved to the complete moment case.

급수전개된 basis를 갖는 모멘트방법에 의한 파수영역의 역산란 방법 (A Spectral Inverse Scattering Technique by Using Moment Method with Series-Expanded Basis)

  • 최현철;김세윤;나정웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1988년도 전기.전자공학 학술대회 논문집
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    • pp.446-449
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    • 1988
  • A spectral inverse technique, which was developed by applying the pulse basis moment method procedure on the direct scattering problem in the reverse sequence for the reconstruction of complex permittivity profiles inside inhomogeneous dielectric objects, is modified to be applicable to the moment method with series-expanded basis. By performing numerical simulations for various type of dielectric objects, it is demonstrated that this inverse technique provides close reconstruction of permittivity profiles. Futhermore, compared to the previous scheme of the pulse basis, the presented method is shown to reduce the computation cost, relative error of reconstructed permittivity profiles by averaging in each cell, and the ill-posedness inherent to this inverse scattering problem.

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A continuity method for bridges constructed with precast prestressed concrete girders

  • Lee, Hwan Woo;Barnes, Robert W.;Kim, Kwang Yang
    • Structural Engineering and Mechanics
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    • 제17권6호
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    • pp.879-898
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    • 2004
  • A method of making simply supported girders continuous is described for bridges with spans of 30-45 m. The splicing method takes advantage of an induced secondary moment to transform the self-weight stresses in the precast simply supported girders into values representative of a continuous girder. The secondary moment results from prestressing of continuity tendons and detensioning of temporary tendons in the girders. Preliminary sections are selected for spliced U-girder bridges with a range of span lengths. Use of the proposed technique results in girder depth reductions of 500-800 mm when compared to standard simply supported I-girder bridges. The flexural behavior of an example bridge with 40-m spans is examined to illustrate the necessary considerations for determining the optimum sequence of splicing operations.