• 제목/요약/키워드: Moment sequence

Search Result 117, Processing Time 0.02 seconds

PRECISE ASYMPTOTICS FOR THE MOMENT CONVERGENCE OF MOVING-AVERAGE PROCESS UNDER DEPENDENCE

  • Zang, Qing-Pei;Fu, Ke-Ang
    • Bulletin of the Korean Mathematical Society
    • /
    • v.47 no.3
    • /
    • pp.585-592
    • /
    • 2010
  • Let {$\varepsilon_i:-{\infty}$$\infty$} be a strictly stationary sequence of linearly positive quadrant dependent random variables and $\sum\limits\frac_{i=-{\infty}}^{\infty}|a_i|$<$\infty$. In this paper, we prove the precise asymptotics in the law of iterated logarithm for the moment convergence of moving-average process of the form $X_k=\sum\limits\frac_{i=-{\infty}}^{\infty}a_{i+k}{\varepsilon}_i,k{\geq}1$

Determination of Natural Frequencies of an Engine Crankshaft Using Finite Elements

  • Park, Myung-Jin
    • The Journal of the Acoustical Society of Korea
    • /
    • v.18 no.4E
    • /
    • pp.20-25
    • /
    • 1999
  • To get accurate natural frequencies of an engine crankshafts, finite element equations of motion are developed, taking real geometries of the shaft into account. For the crankshaft with wide crank webs, a specialized rotating web element is developed. This includes the effects of rotary inertia, gyroscopic moment, and shear. After the finite element equations are constructed, eigenvalues are extracted from the system equations to get natural frequencies, based on the Sturm sequence method which exploits the banded forms of the system matrices to reduce computations. The scheme developed can be used for the free vibration analysis of any type of spinning structures which include skew symmetric gyroscopic moment matrix in the system matrices. The results are compared with experimental data in order to confirm the study.

  • PDF

The Effect on Neglecting the Longitudinal Moment Terms in a Composite Liminate Plate with Stacking Sequence and Fiber Orientation (적층형태 및 보강방향에 따른 복합적층판의 종방향 모멘트 무시효과)

  • Lee, Bong-hak;Lee, Jung-ho;Hong, Chang-Woo;Kim, Kyung-Jin
    • Journal of Industrial Technology
    • /
    • v.18
    • /
    • pp.97-105
    • /
    • 1998
  • The most of the design engineers for construction has academic background of bachelors degree. Theories for advanced composite structures are too difficult for such engineers and some simple but accurate enough methods are necessary. The senior author has reported that some laminate orientations have decreasing values of $D_{16}$, $B_{16}$, $D_{26}$ and $B_{26}$ stiffnesses as the ply number increases. Such plates behave as special orthotropic plates and simple formulas developed by the author can be used. Most of the bridge and building slabs on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms($M_x$) on the relevant partial differential equations of equilibrium. In this paper, the result of the study on the subject problem is presented.

  • PDF

Torsional moment of orthodontic wires (교정용 와이어의 비틀림 모멘트)

  • Choy, Kwangchul;Kim, Kyung-Ho;Park, Young-Chel;Kang, Chang-Soo
    • The korean journal of orthodontics
    • /
    • v.30 no.4 s.81
    • /
    • pp.467-473
    • /
    • 2000
  • As a rectangular wire Is inserted into edgewise brackets the wire exerts a force system three-dimensionally. The force system may include bending force in first and second orders and a torsional force in third order Analytical and experimental studies on bending force have been Introduced, but information about torsion is still lack. The purpose of this study was to estimate the torsional moment in the force system of rectangular arch wires through theoretical and experimental studies. Wires most frequently used for third order control were selected as study materials. Cross sections of 0.016x0.022, 0.017x0.025, 0.019x0.025 inch rectangular wires in foot different materials such as stainless steel(Ormco), TMA(Ormco), NiTi(Ormco), and braided stainless steel (DentaFlex, Dentaurum) were used. The torque/twist rate of each test material was calculated using the torsion formula. Torque/twist rate, yield torsional moment, and ultimate torsional moment were measured with a torque gauge. The torsion formula assesses that the torque/twist rate (T/$\theta$) is proportional to the characteristics of material (G) and cross section (J), and is inversely proportional to the length of wire (L). Most experimental results corresponded with the formula. The relative stiffness was calculated for reference to a logical sequence of wire changes.

  • PDF

A FUNCTIONAL CENTRAL LIMIT THEOREM FOR POSITIVELY DEPENDENT SEQUENCES

  • KIM, TAE-SUNG;KIM, HYUN-CHULL
    • Honam Mathematical Journal
    • /
    • v.16 no.1
    • /
    • pp.111-117
    • /
    • 1994
  • In this note we prove a functional central. limit theorem for LPQD sequences, statisfying some moment conditions. No stationarity is required. Our results imply an extension of Birkel's functional central limit theorem for associated processt'S to an LPQD sequence and an improvement of Birkel's functional central limit theorem for LPQD sequences.

  • PDF

Reinforced Concrete Flat plates Under Combined In-plane and Out-of-plane Loads (바닥하중 및 면내압축력을 받는 플렛 플에이트 슬래브)

  • 박홍근;김의회;홍성걸
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1998.10a
    • /
    • pp.424-429
    • /
    • 1998
  • Numerical studies are performed to investigate the behavior of flat plates under combined in-plane and out-of-plane loads. The numerical model is verified by comparison with experiments for plates simply supported on four edges. Through study on different load combination and loading sequence, the critical load condition that governs the strength of the flat plate is determined. Parametric studies are performed to investigate the buckling coefficient and the effective flexural rigidity so that the moment magnification method is applicable to the flat plates.

  • PDF

THE THEORETICAL AND SITE BEHAVIOUR OF A BRACED DIAPHRAGM WALL-A COMPARISON

  • Kim, Hak-Moon
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1990.10a
    • /
    • pp.111-128
    • /
    • 1990
  • Three numerical analysis carried out for the design of a diaphragm wall were examined by the results of field observation data. Utilizing the wall stiffness, supporting system and construction sequence, the relative merits of those factors on the analysis of diaphragm wall have been investigated and their effects are compared tilth the observed behaviour of the wall. The predicted bending moment and wall displacement by elasto-plastic method agreed well with the observed values. The rigid slab supported system (i.e Top-Down Method) found to be the most effective way of controlling ground movement.

  • PDF

PRECISE ASYMPTOTICS OF MOVING AVERAGE PROCESS UNDER ?-MIXING ASSUMPTION

  • Li, Jie
    • Journal of the Korean Mathematical Society
    • /
    • v.49 no.2
    • /
    • pp.235-249
    • /
    • 2012
  • In the paper by Liu and Lin (Statist. Probab. Lett. 76 (2006), no. 16, 1787-1799), a new kind of precise asymptotics in the law of large numbers for the sequence of i.i.d. random variables, which includes complete convergence as a special case, was studied. This paper is devoted to the study of this new kind of precise asymptotics in the law of large numbers for moving average process under $\phi$-mixing assumption and some results of Liu and Lin [6] are extended to such moving average process.

On the strong law of large numbers for pairwise negative quadrant dependent random variables

  • T. S.;J. I.;H. Y.
    • Communications for Statistical Applications and Methods
    • /
    • v.7 no.1
    • /
    • pp.291-296
    • /
    • 2000
  • Petrov(1996) examined the connection between general moment conditions and the applicability of the strong law lf large numbers to a sequence of pairwise independnt and identically distributed random variables. In this note wee generalize Theorem 1 of Petrov(1996) and also show that still holds under assumption of pairwise negative quadrant dependence(NQD).

  • PDF

IMPROVED UPPER BOUNDS OF PROBABILITY

  • Lee, Min-Young;Jo, Moon-Shik
    • Communications of the Korean Mathematical Society
    • /
    • v.18 no.4
    • /
    • pp.725-736
    • /
    • 2003
  • Let $A_1,{\;}A_2,...,A_n$ be a sequence of events on a given probability space. Let $m_n$ be the number of those $A'_{j}s$ which occur. Upper bounds of P($m_n{\;}\geq{\;}1) are obtained by means of probability of consecutive terms which reduce the number of terms in binomial moments $S_2,n,S_3,n$ and $S_4,n$.