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Diagnostic system to determine the in-service life of dry vacuum pumps

IEE PROCEEDINGS-SCIENCE MEASUREMENT AND TECHNOLOGY 1999年第6期146卷 270-276页

作者： Konishi, S Yamasawa, K Shinshu Univ Dept Elect & Elect Engn Nagano 38085523 Japan

A diagnostic system for dry pumps is proposed. It predicts future pump motor current fi om time-series in-situ measurements. The prediction system has been constructed using a data acquisition system with an online system identification software algorithm. A field test on a low pressure chemical vapour deposition (LPCVD) system for the silicon nitride process predicted large values of motor current, some of which correlated well with actual motel currents as the pump became clogged. The combined use of the predicted motor current and the stability criteria shows promise in predicting the actual service life of a dry pump.

关键词： Control applications in the electronics industry autoregressive moving average processes Control applications to materials processing Electronics industry recursive estimation life testing recursive computation dry vacuum pumps electronic engineering computing Data acquisition systems for control chemical vapour deposition system model Control technology and theory Control engineering computing maintenance engineering Testing preventive maintenance time series diagnostic system Pressure and vacuum control Production facilities and engineering stability criteria time-series in-situ measurements Computerised instrumentation Production engineering computing Other final control equipment future pump motor current Semiconductor industry in-service life determination data acquisition system Vacuum physics control engineering computing online system identification software algorithm ARMAX model identification Control gear and apparatus Instrumentation Maintenance and reliability Surface treatment and coating techniques semiconductor fabrication facility Data acquisition systems Electronic engineering computing Chemical vapour deposition vacuum pumps actual service life Semiconductor technology Industrial applications of IT Plant engineering, maintenance and safety LPCVD system automatic test software data acquisition integrated circuit manufacture

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Decentralized Navigational State Estimation for Networked Multiple Vehicles Subject to Limited Data Rate

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IFAC-PapersOnLine 2015年第28期48卷 1088-1093页

作者： Gao, Chao Zhao, Guorong Liu, Shuai Lu, Jianhua Department of Control Engineering Naval Aeronautical and Astronautical University Zhejiang University Tel: +86-*** Shandong264001 China

In this paper, a decentralized receding horizon fusion strategy (DRHF), mainly based on cooperative packets and relative observations, is proposed for navigational state estimation problems of networked vehicles: a class of linear discrete-time systems with limited data rate. The resulting min-max problem is solved by recursive scheme, which is suitable for recursive computation in online applications. The convergence properties of the optimal estimator are also studied. Finally, an illustrative example of networked UAVs is given to demonstrate the main features of the proposed estimator design approach. © 2015

关键词： Discrete time control systems Digital control systems State estimation Convergence properties Limited data Linear discrete time systems Networked systems Quantization effects Receding horizon recursive computation Relative observation

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computation OF CENTRAL AND NON-CENTRAL F DISTRIBUTIONS

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COMMUNICATIONS IN STATISTICS PART A-THEORY AND METHODS 1976年第3期A 5卷 261-281页

作者： AMOS, DE SANDIA LABS ALBUQUERQUENM 87115

Recursion relations suitable for rapid computation are derived for the cumulative distribution of F′ = (X/m)/(Y/n) where X is χ2(λ, m) and Y is independently χ2(n). When n is even no complicated function evaluatio... 详细信息

Recursion relations suitable for rapid computation are derived for the cumulative distribution of F′ = (X/m)/(Y/n) where X is χ²(λ, m) and Y is independently χ²(n). When n is even no complicated function evaluations are needed. For n odd, a special doubly noncentral t distribution is needed to start the computation. Series representations for this t distribution are given with rigorous bounds on truncation errors. Proper recursion techniques for numerical evaluation of the special functions are given.

关键词： recursive computation doubly noncentral t distribution

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The Value of Information in Spatial Decision Making

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MATHEMATICAL GEOSCIENCES 2010年第2期42卷 141-163页

作者： Bhattacharjya, Debarun Eidsvik, Jo Mukerji, Tapan IBM TJ Watson Res Ctr Yorktown Hts NY USA NTNU Dept Math Sci Trondheim Norway Stanford Univ Dept Energy Resources Engn Stanford CA 94305 USA

Experiments performed over spatially correlated domains, if poorly chosen, may not be worth their cost of acquisition. In this paper, we integrate the decision-analytic notion of value of information with spatial statistical models. We formulate methods to evaluate monetary values associated with experiments performed in the spatial decision making context, including the prior value, the value of perfect information, and the value of the experiment, providing imperfect information. The prior for the spatial distinction of interest is assumed to be a categorical Markov random field whereas the likelihood distribution can take any form depending on the experiment under consideration. We demonstrate how to efficiently compute the value of an experiment for Markov random fields of moderate size, with the aid of two examples. The first is a motivating example with presence-absence data, while the second application is inspired by seismic exploration in the petroleum industry. We discuss insights from the two examples, relating the value of an experiment with its accuracy, the cost and revenue from downstream decisions, and the design of the experiment.

关键词： Value of information Value of experiment Markov random field Spatial decision making Decision analysis recursive computation

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ON THE computation OF CERTAIN INTEGRALS CONTAINING THE MODIFIED BESSEL-FUNCTION I0(ZETA)

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MATHEMATICS OF computation 1982年第160期39卷 625-637页

作者： LASSEY, KR Institute of Nuclear Sciences D.S.I.R. Private Bag Lower Hutt Netherlands

Abstract: Efficient stratagems are developed for numerically evaluating one- and two-dimensional integrals over x, y with integrand $\exp ( - x - y){I_0}(2\sqrt {pxy} )$. The integrals are expressed in terms o... 详细信息

Abstract: Efficient stratagems are developed for numerically evaluating one- and two-dimensional integrals over x, y with integrand $\exp ( - x - y){I_0}(2\sqrt {pxy} )$. The integrals are expressed in terms of convergent series, which exhibit the correct limiting behavior, and which can be evaluated recursively. The performances of these stratagems are compared with numerical integration.

关键词： Modified Bessel functions integrals of Bessel functions recursive computation

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COVARIANCE-MATRIX computation OF THE STATE VARIABLE OF A STATIONARY GAUSSIAN PROCESS

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ANNALS OF THE INSTITUTE OF STATISTICAL MATHEMATICS 1978年第3期30卷 499-504页

作者： AKAIKE, H

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A General Framework for Constructing Locally Self-Normalized Multiple-Change-Point Tests

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JOURNAL OF BUSINESS & ECONOMIC STATISTICS 2024年第2期42卷 719-731页

作者： Cheng, Cheuk Hin Chan, Kin Wai Chinese Univ Hong Kong Dept Stat Hong Kong Peoples R China

We propose a general framework to construct self-normalized multiple-change-point tests with time series data. The only building block is a user-specified single-change-detecting statistic, which covers a large class of popular methods, including the cumulative sum process, outlier-robust rank statistics, and order statistics. The proposed test statistic does not require robust and consistent estimation of nuisance parameters, selection of bandwidth parameters, nor pre-specification of the number of change points. The finite-sample performance shows that the proposed test is size-accurate, robust against misspecification of the alternative hypothesis, and more powerful than existing methods. Case studies of the Shanghai-Hong Kong Stock Connect turnover are provided.

关键词： Nonparametric recursive computation Time series Tuning-free

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A NEW computationAL APPROACH FOR STOCHASTIC FLUID MODELS OF MULTIPLEXERS WITH HETEROGENEOUS SOURCES

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QUEUEING SYSTEMS 1995年第1-2期20卷 85-116页

作者： IGELNIK, B KOGAN, Y KRIMAN, V MITRA, D AT&T BELL LABS HOLMDELNJ 07733 TECHNION ISRAEL INST TECHNOL FAC IND ENGN & MANAGEMENTIL-32000 HAIFAISRAEL AT&T BELL LABS MURRAY HILLNJ 07974

In this paper we derive an efficient computational procedure for the system in which fluid is produced by N-1 on-off sources of type 1, N-2 on-off sources of type 2 and transferred to a buffer which is serviced by a channel of constant capacity. This is a canonical model for multiservice ATM multiplexing, which is hard to analyze and also of wide interest. This paper's approach to the computation of the buffer overflow probability, G(x) = Pr(buffer content > x), departs from all prior approaches in that it transforms the computation of G(x) for a particular x into a recursive construction of an interpolating polynomial. For the particular case of two source types the interpolating polynomial is in two variables. Our main result is the derivation of recursive algorithms for computing the overflow probability G(x) and various other performance measures using their respective relations to two-dimensional interpolating polynomials. To make the computational procedure efficient we first derive a new system of equations for the coefficients in the spectral expansion formula for G(x) and then use specific properties of the new system for efficient recursive construction of the polynomials. We also develop an approximate method with low complexity and analyze its accuracy by numerical studies. We compute G(x) for different values of x, the mean buffer content and the coefficient of the dominant exponential term in the spectral expansion of G(x). The accuracy of the approximations is reasonable when the buffer utilization characterized by G(O) is more than 10(-2).

关键词： FLUID MODELS ATM MULTIPLEXING BUFFER OVERFLOW PROBABILITY 2-DIMENSIONAL INTERPOLATING POLYNOMIALS recursive computation

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Exact and Approximate recursive Calculations for Binary Markov Random Fields Defined on Graphs

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JOURNAL OF computationAL AND GRAPHICAL STATISTICS 2012年第3期21卷 758-780页

作者： Tjelmeland, Hakon Austad, Haakon Michael Norwegian Univ Sci & Technol Dept Math Sci N-7491 Trondheim Norway

In this article, we propose computationally feasible approximations to binary Markov random fields (MRFs). The basis of the approximation is the forward-backward algorithm. The exact forward-backward algorithm is computationally feasible only for fields defined on small lattices. The forward part of the algorithm computes a series of joint marginal distributions by summing out each variable in turn. We represent these joint marginal distributions by interaction parameters of different orders. The approximation is defined by approximating to zero all interaction parameters that are sufficiently close to zero. In addition, an interaction parameter is approximated to zero whenever all associated lower-level interactions are (approximated to) zero. If sufficiently many interaction parameters are set to zero, the algorithm is computationally feasible both in terms of computation time and memory requirements. The resulting approximate forward part of the forward-backward algorithm defines an approximation to the intractable normalizing constant, and the corresponding backward part of the algorithm defines a computationally feasible approximation to the MRF. We present numerical examples demonstrating the quality of the approximation. The supplementary materials for this article, which are available online, include two appendices and R and C codes for the proposed recursive algorithms.

关键词： Approximate inference Approximate normalizing constant Autologistic model Forward-backward algorithm Ising model recursive computation

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ON NONNULL DISTRIBUTION OF RANKS

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COMMUNICATIONS IN STATISTICS-SIMULATION AND computation 1986年第3期15卷 591-608页

作者： CALLFAS, D MOHANTY, SG Department of Mathematics and Statistics McMaster University Hamilton Canada

Consider the two-sample testing problem from continuous distributions with distribution functions F and G such that G= Y(F) where is a non-decreasing onto function from (0,1) to (0,1). when it is not the identity mapping is usually called Lehmannfs alternative. An algorithm to derive the distribtuions of some rank order statistics under a general rule ψ(u) is developed.

关键词： Lehmann alternatives two-sample non-parametric tests recursive computation

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