Based on a real industrial application, 3 new system reliability models are proposed: combined k-out-of-n :F and consecutive-k(c)-out-of-n :F system? combined k-out-of-m . n:F and linear connected-(r, s)-out-of-(m, n)...
详细信息
Based on a real industrial application, 3 new system reliability models are proposed: combined k-out-of-n :F and consecutive-k(c)-out-of-n :F system? combined k-out-of-m . n:F and linear connected-(r, s)-out-of-(m, n): F system, combined k-out-of-m . n: F, consecutive-k(c)-out-of-n : F and linear connected-(r, s)-out-of-(m, n):F system. Reliability evaluation algorithms are provided for these models. The computation times of the algorithms for these models are, respectively: . O(n. k), . O(k . n . (2(m) . s(m-r+1)) . O(k . n . (2k(c))(m) . s(m-r+1)), The algorithms are used for system reliability evaluation of furnace systems. The concept of the combined k-out-of-n : F and 1-dimensional and 3-dimensional consecutive-k-out-of-n : F systems can be extended to other variations of the consecutive-k-out-of-n systems, e.g., the consecutive-k-out-of-n : G system and 1-dimensional and 2-dimensional r-within-k-out-of-n : F systems, The concept of Markov Chain Imbeddable (MIS) systems is another excellent tool that can be used for analysis of such combined system structures.
The modeling of a set of impedance values given either experimentally or heuristically for implementation as a time-domain impedance-equivalent boundary condition (TDIBC) is discussed. It is shown that impedance as de...
详细信息
The modeling of a set of impedance values given either experimentally or heuristically for implementation as a time-domain impedance-equivalent boundary condition (TDIBC) is discussed. It is shown that impedance as defined by the reflection of plane harmonic waves when extended for broadband time-domain applications can correspond to mathematically feasible but physically unacceptable noncausal reflection processes. Given a set of impedance data on a finite, positive, and real frequency range, it is possible to construct causal time-domain models that render efficient implementation of TDIBC for broadband reflections. However, these models defined by measurement of harmonic waves may not be valid For the reflection of impulses, for which measurement of transient reflections is warranted.
Efficient algorithms for shape preserving approximation to curves and surfaces are very important in shape design and modelling in CAD/CAM systems. In this paper, a local algorithm using piecewise generalized conic se...
详细信息
Efficient algorithms for shape preserving approximation to curves and surfaces are very important in shape design and modelling in CAD/CAM systems. In this paper, a local algorithm using piecewise generalized conic segments is proposed for shape preserving curve interpolation. It is proved that there exists a smooth piecewise generalized conic curve which not only interpolates the data points, but also preserves the convexity of the data. Furthermore, if the data is strictly convex, then the interpolant could be a locally adjustable GC(2) curve provided the curvatures at the data points are well determined. It is also shown that the best approximation order is O(h(6)). An efficient algorithm for the simultaneous computation of points on the curve is derived so that the curve can be easily computed and displayed. The numerical complexity of the algorithm for computing N points on the curve is about 2N multiplications and N additions. Finally, some numerical examples with graphs are provided and comparisons with both quadratic and cubic spline interpolants are also given.
The Wilcoxon signed rank test is a well known statistical test based on Wilcoxon's T-n(+) statistic. When n is large enough, the lower tail probability P-0 (T-n(+) less than or equal to x) of T-n(+) under H-0 : th...
详细信息
The Wilcoxon signed rank test is a well known statistical test based on Wilcoxon's T-n(+) statistic. When n is large enough, the lower tail probability P-0 (T-n(+) less than or equal to x) of T-n(+) under H-0 : theta = 0 may be computed easily by a normal approximation. We propose in this paper a recursive, real-time algorithm which computes this probability when n is small.
Lattice filters have properties that are well suited for application to parameter identification of flexible structures. The problem of both order and parameter estimation is addressed where the numerical difficulties...
详细信息
Lattice filters have properties that are well suited for application to parameter identification of flexible structures. The problem of both order and parameter estimation is addressed where the numerical difficulties of an embedded lattice filter are avoided by applying a periodic lattice filter. This formulation is quite natural to estimate system order by applying Akaike's Information Criterion to each channel of the periodic lattice filter. Several examples including nonstationary cases are simulated to demonstrate these facts.
This paper focuses on the study of dynamic modeling of nonholonomic wheeled mobile robotic manipulators, which consist of a serial manipulator with elastic joints and an autonomous wheeled mobile platform. To avoid co...
详细信息
This paper focuses on the study of dynamic modeling of nonholonomic wheeled mobile robotic manipulators, which consist of a serial manipulator with elastic joints and an autonomous wheeled mobile platform. To avoid computing the Lagrange multipliers associated with the nonholonomic constraints, the approach of Gibbs-Appell (G-A) formulation in recursive form is adopted. For modeling the system completely and precisely, dynamic interactions between the manipulator and the mobile platform, as well as both nonholonomic constraints associated with the no-slipping and the no-skidding conditions, are included. Based on developed formulation, an algorithm is proposed that recursively and systematically derives the equation of motion. In this algorithm, in order to improve the computational complexity, all mathematical operations are done by only 3 x 3 and 3 x 1 matrices. Also, all dynamic expressions of a link are expressed in the same link local coordinate system. Finally, two computational simulations for mobile manipulators with rigid and elastic joints are presented to indicate the capability of this algorithm in generating the equation of motion of mobile robotic manipulators with high degree of freedom. (C) 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.
The generalized multi-state k-out-of-n:G system model defined by Huang et al. [5] provides more flexibilities for modeling of multi-state systems. However, the performance evaluation algorithm they proposed for such s...
详细信息
The generalized multi-state k-out-of-n:G system model defined by Huang et al. [5] provides more flexibilities for modeling of multi-state systems. However, the performance evaluation algorithm they proposed for such systems is not efficient, and it is applicable only when the k(i) values follow a monotonic pattern. In this paper, we defined the concept of generalized multi-state k-out-of-n:F systems. There is an equivalent generalized multi-state k-out-of-n:G system with respect to each generalized multi-state k-out-of-n:F system, and vice versa. The form of minimal cut vector for generalized multi-state k-out-of-n:F systems is presented. An efficient recursive algorithm based on minimal cut vectors is developed to evaluate the state distributions of a generalized multi-state k-out-of-n:F system. Thus, a generalized multi-state k-out-of-n:G system can first be transformed to the equivalent generalized multi-state k-out-of-n:F system, and then be evaluated using the proposed recursive algorithm. Numerical examples are given to illustrate the effectiveness and efficiencies of the proposed recursive algorithms.
The paper discusses two algorithms for solving the Zakai equation in the time-homogeneous diffusion filtering model with possible correlation between the state process and the observation noise. Both algorithms rely o...
详细信息
The paper discusses two algorithms for solving the Zakai equation in the time-homogeneous diffusion filtering model with possible correlation between the state process and the observation noise. Both algorithms rely on the Cameron-Martin version of the Wiener chaos expansion, so that the approximate filter is a finite linear combination of the chaos elements generated by the observation process. The coefficients in the expansion depend only on the deterministic dynamics of the state and observation processes. For real-time applications, computing the coefficients in advance improves the performance of the algorithms in comparison with most other existing methods of nonlinear filtering. The paper summarizes the main existing results about these Wiener chaos algorithms and resolves some open questions concerning the convergence of the algorithms in the noise-correlated setting. The presentation includes the necessary background on the Wiener chaos and optimal nonlinear filtering.
The multi-state k-out-of-n system model finds wide applications in industry, and has been extensively studied in recent years. This model has also been generalized to the multi-state weighted k-out-of-n system model. ...
详细信息
The multi-state k-out-of-n system model finds wide applications in industry, and has been extensively studied in recent years. This model has also been generalized to the multi-state weighted k-out-of-n system model. recursive methods, and universal generating functions (UGF) are two primary algorithms for exact performance evaluation of multi-state k-out-of-n systems. However the computational burden becomes the crucial factor when there is a "dimension damnation" problem caused by the increase in the number of components in the system, and the number of possible states a component may be in. In situations wherein exact values of system reliability are not necessary, we may use more efficient algorithms to approximate system reliability. In this paper, we develop a comprehensive framework for reliability approximation of multi-state weighted k-out-of-n systems. Two fuzzy based multi-state weighted k-out-of-n system models are defined. Procedures for building these two models from the conventional models are also introduced. The fuzzy recursive methods, and fuzzy UGF techniques are developed to evaluate such systems. The clustering technique, and curve fitting method are used to determine the fuzzy weights, and probabilities of states in the models.
Compensation of nonlinear smart sensors is an important topic that must always be considered to assure the accuracy of measurement systems. Nowadays, with the advent of microprocessor devices in smart sensors, advance...
详细信息
Compensation of nonlinear smart sensors is an important topic that must always be considered to assure the accuracy of measurement systems. Nowadays, with the advent of microprocessor devices in smart sensors, advanced compensation algorithms can be implemented to improve the accuracy of measurement. In this paper, an inverse modeling methodology based on B-spline is proposed for the compensation of nonlinear smart sensors. To avoid complicated least squares solution of the B-spline, a training algorithm in a recursive form is proposed to reduce the training cost and make the on-chip training of B-spline available. Moreover, the choices of B-spline knots and training points are important designed parameters in this methodology. So the free knot insertion algorithm and training points' selection method are used prior to the training process to improve the accuracy of the inverse models and avoid the under and over fitting. Simulations and results are presented to validate the theoretical expectations. (C) 2011 Elsevier Ltd. All rights reserved.
暂无评论