The author compares the performances of three optimization algorithms as concerns their efficiency in parameter estimation and minimizing the criterion function in the field of rainfall-runoff modeling. This modeling has been put within the framework of nonlinear regression analysis; some...

The magnetostatic potential due to the magnetization existing in the magnetic media is characterized by a variational principle defined in the whole space. Representing the magnetostatic potential in the exterior of the magnetic media by its values on the boundary of an unbounded exterior space,...

This paper deals with the problem of producing several statistically independent streams of random numbers. Existing techniques are discussed and a new method is proposed. Statistical tests carried out on all the circuits described show that the proposed method yields random number sequences...

This paper extends the theory of the Accelerated Overrelaxation (AOR) method and presents what is called Symmetric AOR (SAOR) method. This is done in a way analogous to the one where the SSOR method is obtained from the SOR one. In addition the theoretical and computational results which are...

We define complex systems, from molecular ensembles and networks to galactic clusters, as fluid-plastic-elastic systems in which bulk/shear viscosity ratios are large, with the consequence that interactions among parts at any level lead to internalization of action (energy × time) and to...

In January 1981, the United States Council on Environmental Quality [U.S.C.E.Q.] released a report on “Global Energy Futures and the Carbon Dioxide Problem”. Perhaps more than any other document this report has impressed upon the scientific community the necessity to initiate a detailed and...

The “Tablas de Daimiel” National Park originates at the interface of a large fluvial system (Guadiana river) and the discharge area of a big aquifer (Llanura Manchega). The Park has been registered “A class” in the UICN catalogue of marshy zones for being an important bird sanctuary. The...

Whenever a model is not identifiable, there exist several parameter vectors θ which yield the same input-output behavior, so that any further interprtation of θ is questionable. In this paper two methods which can be used to test state-space models for identifiability with a global approach...

By analyzing the hopscotch iteration as a composite, three-level, time marching scheme on fixed lines, an alternate approach to obtaining Gourlay's prediction [1] of an optimal value for the convergence parameter R =τh2 is provided. In some cases this analysis allows rapid convergence to be...

This paper presents a reformulation of the identifiability problem, on the basis of equivalence between a model and the process it represents. Following a brief review of the major definitions in the literature, the concept of “near-equivalence” is introduced for both theoretical and real...