• Title, Summary, Keyword: moment bounds

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BOUNDS ON PROBABILITY FOR THE OCCURRENCE OF EXACTLY r, t OUT OF m, n EVENTS

  • Lee, Min-Young
    • Communications of the Korean Mathematical Society
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    • v.12 no.2
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    • pp.393-401
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    • 1997
  • Let $A_1,A_2,\cdots,A_m$ and $B_1,B_2,\cdots,B_n$ be two sequences of events on a given probability space. Let $X_m$ and $Y_n$, respectively, be the number of those $A_i$ and $B_j$, which occur we establish new upper and lower bounds on the probability $P(X=r, Y=t)$ which improve upper bounds and classical lower bounds in terms of the bivariate binomial moment $S_{r,t},S_{r+1,t},S_{r,t+1}$ and $S_{r+1,t+1}$.

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IMPROVED UPPER BOUNDS OF PROBABILITY

  • Lee, Min-Young;Jo, Moon-Shik
    • Communications of the Korean Mathematical Society
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    • v.18 no.4
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    • pp.725-736
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    • 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 $S_4,n$.

Drift Control for Multistory Moment Frames under Lateral Loading

  • Grigorian, Carl E.;Grigorian, Mark
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.355-365
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    • 2013
  • The paper reports results of recent studies on the effects of column support conditions on the lateral displacements of moment frames at incipient collapse. The article presents a number of exercises in the plastic theory of structures that lead to useful design formulae. It has been shown that Drift Shifting (DS) is caused due to differences in the stiffnesses of adjoining columns, and that changes in drift ratios are more pronounced at first level column joints in both fixed as well as pinned base frames. In well proportioned moment frames, DS in the upper levels could be minimized, even reduced to zero. It has been demonstrated that DS can be eliminated in properly designed fixed and grade beam supported (GBS) moment frames. Several examples, including symbolic P-delta effects, have been provided to demonstrate the validity and the applications of the proposed ideas to the design and drift control of moment frames. The proposed methodology is exact within the bounds of the theoretical assumptions and is well suited for preliminary design and teaching purposes.

THE OPTIMAL BIVARIATE BONFERRONI-TYPE LOWER BOUNDS

  • Lee, Min-Young
    • Communications of the Korean Mathematical Society
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    • v.14 no.4
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    • pp.789-795
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    • 1999
  • Let $A_1$,A$_2$…, A\ulcorner and B$_1$,B$_2$…, B\ulcorner be two sequences of events on the same probability space. Let X= X\ulcorner(A) and Y-Y\ulcorner)(B), repectively, by the number of those A\ulcorner and B\ulcorner which oc-cur. We establish bivariate lower bounds on the distribution P(X$\geq$1, Y, $\geq$1)and P(X$\geq$i , $Y\geq$j)by linear combinations of the bino-mial moments S\ulcorner, \ulcorner, 1$\leq$i$\leq$j

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QFT application on force controller design for aircraft control surface load simulator (항공기 조종면 부하재현 구동장치의 force control)

  • 남윤수;이진영;이기두
    • 제어로봇시스템학회:학술대회논문집
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    • pp.1684-1687
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    • 1997
  • A dynamic load simulator which can reproduce on-ground the hinge moment of aircraft control surface is and essential rig for the loaded performance test of aircraft test of aircraft acutation system. The hinge moment varies wide in the aricraft flight enveloped depending on specific flight condition and maneuvering status. To replicate the wide spectrum of this hinge moment variation within some accuracy bounds, a force controller is designed based on the Quantiative Feedback Theory (AFT). Through the analysis on hinge moment dynamics, a design specification for the force controller is suggested. The efficacy of QFT force controller is verivied by simulation, in which combined aricraft dynamics/flight control law and hydraulic actuation system dynamics of aircraft control surface are considered.

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DEPENDENCE IN M A MODELS WITH STOCHASTIC PROCESSES

  • KIM, TAE-SUNG;BAEK, JONG-IL
    • Honam Mathematical Journal
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    • v.15 no.1
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    • pp.129-136
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    • 1993
  • In this paper we present of a class infinite M A (moving-average) sequences of multivariate random vectors. We use the theory of positive dependence to show that in a variety of cases the classes of M A sequences are associated. We then apply the association to establish some probability bounds and moment inequalities for multivariate processes.

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System Reliability Analysis of a Shallow Foundation using Correlated Failure Modes (유상관 파양류형에 의한 얕은 기초의 신뢰도 해석)

  • Kim, Yong-Pil;Im, Byeong-Jo;Im, Chung-Mo
    • Geotechnical Engineering
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    • v.2 no.3
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    • pp.67-78
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    • 1986
  • This paper presents how to determine the system reliability of a typical shallow foundation constituted four potential correlated failure modes of hearing capacity (BCM), consolidation settlement (CSM), moment (MFM), and tension shear (PCM). Through the idenfication of the distinct and different modes and evaluation of range of system reliability, the obtained conclusions are as follows; 1. The CSM and the PCM are the lowest and highest of reliability indices of single performance function, and the BCM and the MFM are medium of them. 2. For the correlated failure modes, the hi-modal bounds Is narrower and lower of failure probability than the unimodal bounds. Not to be overestimated, therefore, the system reliability should be based on the second-order bounds using correlated performance functions.

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Analysis of COMS In-Orbit Test for Moment of Inertia Measurement (천리안위성 관성모멘트의 궤도상 측정 시험 분석)

  • Park, Keun-Joo;Park, Young-Woong;Choi, Hong-Taek
    • Aerospace Engineering and Technology
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    • v.10 no.2
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    • pp.121-127
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    • 2011
  • In the attitude and orbit control subsystem design, the moment of inertia of the satellite is the major contributor to be considered. Satellites equipped with large solar arrays need to measure the moment of inertia accurately to avoid the interference of the thruster actuation period with its flexible mode. In this paper, the in-orbit tests of COMS to measure the moment of inertia are described. Then, the differences between the measured through in-orbit test and the predicted are compared. Finally, it is verified that the differences are below uncertainty bounds considered in the critical design of COMS attitude and orbit control subsystem.

Design for moment redistribution in FRP plated RC beams

  • Oehlers, Deric John;Hasketta, Matthew;Mohamed Ali, M.S.
    • Structural Engineering and Mechanics
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    • v.38 no.6
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    • pp.697-714
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    • 2011
  • Assessing the ductility of reinforced concrete sections and members has been a complex and intractable problem for many years. Given the complexity in estimating ductility, members are often designed specifically for strength whilst ductility is provided implicitly through the use of ductile steel reinforcing bars and by ensuring that concrete crushing provides the ultimate limit state. As such, the empirical hinge length and neutral axis depth approaches have been sufficient to estimate ductility and moment redistribution within the bounds of the test regimes from which they were derived. However, being empirical, these methods do not have a sound structural mechanics background and consequently have severe limitations when brittle materials are used and when concrete crushing may not occur. Structural mechanics based approaches to estimating rotational capacities and rotation requirements for given amounts of moment redistribution have shown that FRP plated reinforced concrete (RC) sections can have significant moment redistribution capacities. In this paper, the concept of moment redistribution in beams is explained and it is shown specifically how an existing RC member can be retrofitted with FRP plates for both strength and ductility requirements. Furthermore, it is also shown how ductility through moment redistribution can be used to maximise the increase in strength of a member. The concept of primary and secondary hinges is also introduced and it is shown how the response of the non-hinge region influences the redistribution capacity of the primary hinges, and that for maximum moment redistribution to occur the non-hinge region needs to remain elastic.

A Robust Neural Control of Robot Manipulator Operated Under the Sea (해저작업 로봇 매니퓰레이터의 강건한 신경망 제어기)

  • 박예구;최형식;이민호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.337-341
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    • 1995
  • This paper presents a robust control scheme using a multilayer network for the robot manipulator operating under the sea which has large uncertainties such as the buoyancy and the added mass/moment of inertia. The multilayer neural network acts as a compensator of the conventional sliding mode controller to maintain the control performance when the initial assumptions of uncertainty bounds are not valid. By the computer simulation results, the proposed control scheme dose not effectively compensate large uncertainties, but also reduces the steady stare error of the conventional sliding mode controller.

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