摘要:

AbstractIn this paper three different recursive ARMA identification methods are examined and compared to each other in their ability to perform deconvolution of seismic signals. These methods are the extended least squares, the recursive maximum likelihood and a combined instrumental variable-extended least squares method. An approach is also proposed in case of a non-minimum phase seismic wavelet, which uses Kalman filtering of an appropriate state variable model combined with a recursive least squares or instrumental variable algorithm. Results are presented which illustrate each of the above methods.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759918

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractOne model has been developed for assessing the atmospheric dispersion of radioactivity from a typical 1000 MWe coal-fired power station. The model is equally applicable to nuclear power stations.The applicability of a specific technique for numerically inverting the Laplace transform has been demonstrated. The investigation has shown that the atmospheric concentration of radioactivity can reach high values comparable to or exceeding releases under normal operations from nuclear plants. It is, therefore, suggested that coal-fired stations should be subjected to the same environmental impact statements as nuclear power plants.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759919

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe analyaia of dynamic flight teat meaaurements can be interpreted aa a dynamic system identification problem. Given meaaurements of the input signals (control surface angle deflections) and output signals (accelerometer and rate gyro outputa, air apeed, attitude deviation) the taak is to reconstruct the aircraft’s state vector time history and, in the case of linear models of the aircraft, eatimate a set of aerodynamic parameters, the so-called stability- and control derivstives. This system identification problem can be put in the framework of the Maximum Likewhood(ML) eatimation theory. The calculation of ML parameter estimates requires the solution of a aet of non-linear equations.In the paper it is shown that when a set of conditions concerning the flight test instrumentation configuration is fulfilled, the above mentioned identification problem can be decomposed into a separate estimation problem followed by a parameter identification problem. In the case of linear equations of motion, both ot these problems are linear. These are much easier to solve than the original non-linear problem.In the present work a one-step method and a two-step method are developped and the performance of both methods is compared, using simulated flight test data and linear equations of motion. Both methods are shown to generate equivalent results when the underlying assumptions of the ML method are fulfilled. Finally the effect of different types of aerodynamic model errors on the estimates of the one-step method and two-step method are investigated.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759920

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractValidation of system-models is a crucial part in the model-building procedure. This is especially true in the case of complex systems, e.g. biological systems, In particular when some conclusions shall be drawn with respect to the Internal system-characteristics based on the in-put-output behaviour.In this paper the aspect of the heuristic validity of a nonlinear model of the physiologically closed human cardiovascular system, which has been successfully used for simulation and parameter estimation, Is analysed by applying the modern system-concepts of controllability Bnd observability. It will be shown that the model is valid with respect to its intended use. Furthermore, an interesting conjecture on the controllability properties of the real biological system will result.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759921

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractTwo-dimensional recursive digital filters have the advantages of flexibility and accuracy, typical of digital processing systems, and the ability to perform the desired filtering with significuntly fewer operations than non-recuvsive filters. In this paper some useful symmetries are exploited in the design of filters with responses which are approximately circularly symmetric. With the imposition of quadrantal symmetry, followed by further symmetry about the 45°line, a particular filter structure is derived using a cascade of causal second order sections. Each section uses only four independent coefficients and possesses a separable denominator, with a resulting simplification of stability testing and stabilization which can now be done by using one dimensional techniques. The Fletcher-Powell non-linear optimization routine is used with a mean squared error criterion, which enables the optimum vulue of the Rain to be incorporated into the objective Function to be minimized.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759922

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractModelling and identification of a multivariable blending process in cement production is studied. The Elementary Sub system (ESS) representation and the associated structure and parameter estimation procedures are applied to identify the dynamic relationships among the raw material flows and the oxides contained in the raw-meal.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759923

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractIn this paper we propose a method for approximate analysis of multiple chain closed queueing networks. The proposed method is based on a decomposition of the multiple chain problem into equivalent single chain subproblems by estimating the equivalent mean service time for each queue in every single chain. Then a set of single chain problems is solved, the multiple chain network performance is calculated from the results of the previous step and so on. The algorithm allows the computation of moments of the performance measures, such as queue lengths, waiting times, queueing times, etc.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759924

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

摘要:

AbstractThe modelling of large systems is greatly simplified if their hierarchical decomposition and interconnection structure can be described graphically. The paper describes a system allowing input of block diagrams and continuous zooming to view internal details. Model equations are automatically transformed to assignment statements when possible, allowing efficient explicit integration routines to be used without additional burdens for the modeller.

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759925

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759926

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor

ISSN:0228-6203    

DOI:10.1080/02286203.1985.11759927

出版商:Taylor&Francis    

年代:1985

数据来源: Taylor