Showing papers in "International Journal of Modelling and Simulation in 1994"

A study of container yard equipment allocation strategy in Hong Kong

Abstract: The authors examine several strategies for the allocation of container yard equipment in terms of container handling throughput,equipment utilization, and waiting times. Data from a large container...

Simulation study of load balancing in a heterogeneous distributed system model

Abstract: The effects of load balancing on system and program performance of a heterogeneous distributed system model are studied using simulation techniques. A closed queuing network model is considered wit...

Numerical Calculations For Pulsating Flow Past A Bluff Body

Abstract: In this paper, flow characteristics are obtained by using the penalty function finite element method with the balancing diffusivity upwind scheme to solve the governing Navier-Stokes equations. The...

Adaptive Thermo-Geometrical Models For Simulation Of Consumable-Electrode Welding

Abstract: In this article, three complementary thermal models of welding with material transfer are developed and evaluated. First, a lumped analytical model of the weld bead geometry integrates separate clo...

Dynamic analysis and motion control of the multibody space crane

Abstract: In this investigation the use of general purpose multibody computer programs in the dynamic analysis and control of space applications is demonstrated. The dynamics and control of a three-degree of freedom space crane is examined. An inverse-dynamics procedure is used to evaluate the joint torques that produce the desired trajectory of the end effector. The obtained results are verified using existing general purpose multibody computer programs that employ the augmented formulation in which the generalized joint forces are expressed in terms of the constraint Jacobian matrix and Lagrange multipliers. The relationships between the actual driving joint torques of the space crane and the generalized joint forces expressed in terms of Lagrange multipliers are derived and used to develop a general methodology for the control of space mechanisms using general purpose multi body computer codes. Several algorithms for the motion control of the space crane are examined. These algorithms include the open-lo...

A new iterative algorithm for image restoration based on maximum likelihood principle

Abstract: Considers the development and implementation of a new gradient-based algorithm for image restoration. The algorithm assumes that the original intensity signal s(x) has been affected by a known linear, but not necessarily space-invariant, point spread function in an additive white Gaussian noise environment. It is assumed that the covariance function of s(x) is known a priori. Based on these assumptions, the algorithm tends toward the maximum likelihood estimate of s(x) using the steepest ascent routine. The developed algorithm is reduced to the least squares error restoration scheme reported by E.S. Angel and A.K. Jain (1978) in the absence of noise when the covariance function of s(x) is an impulse function. Simulation experiments are presented. >

Algorithms for change detection on locally stationary multichannel signals

Abstract: In this paper we develop algorithms, resting on the principle of Recursive Least-Squares, for the treatment of multichannel signals. A method of modelling in packs is presented in the scalar and ve...

A new procedure for multi-input dynamic systems identification

Abstract: One of the major problem for the identification of industrial multi-input multi-output (MIMO) systems is the too small variance of some signals collected during several experiments. Usually, sufficient information exist but are often dispersed among many data-files. In this case, it is difficult to conciliate this information to build a single well adapted model. The ALS procedure (Alternate Least Squares) has been performed in order to solve this kind of problem. In the first part of this paper, the authors present the principle of the ALS procedure; the details of the complete algorithm are given in part two. Then, based on some examples, a comparison of the Prediction Error Method (PEM) with our new method is presented.

Design Of A Controller For A System With Flexible Modes

Abstract: This paper presents a systematic procedure for designing a controller for a system with flexible modes.The effects of in exactness of the plant model are examined and a numerical example is included.

A Simulation Study Of The Performance Of Several Estimation Procedures For Linear Regression Models

Abstract: The present work examines an additional approach to regression analysis by introducing the Relative Least Squares technique to model fitting. In addition to the usual Mean Square Error (MSE) criter...