1. LET THE GAMES BEGIN: THE OPENING CEREMONIES. For those who think globally, "down under" may provoke thoughts of Australia-the home of the 2000 Olympic Games. For those who think rationally, "down under" may provoke thoughts of denominators of fractions. In this paper, we hope to provoke both. In basic diophantine approximation, the name of the game is to tackle the following: How close do in...

This paper proposes to investigate the impact of …nancialization on energy markets (oil, gas, coal and electricity European forward prices) during both normal times and extreme ‡uctuation periods through an original behavioral and emotional approach. To this aim, we propose a new theoretical and empirical framework based on a heterogeneous agents model in which fundamentalists and chartists co-...

We consider the problem of describing the possible spectra of an acoustic operator with a periodic finite-gap density. We construct flows on the moduli space of algebraic Riemann surfaces that preserve the periods of the corresponding operator. By a suitable extension of the phase space, these equations can be written with quadratic irrational-ities.

the main design objective of axial compressor is the efficiency increasing, pressure ratio and weight loss. these three parameters are used as an objective function and they are computed according to adopted design procedures. in this paper, a design method is presented that named quasi-three-dimensional. physical flow conditions are applied to design by some constraints to avoid irrational res...

Sufficient and necessary conditions for the stability of positive feedback interconnections of negative imaginary systems are derived via an integral quadratic constraint (IQC) approach. The IQC framework accommodates distributed-parameter systems with irrational transfer function representations, while generalising existing results in the literature and allowing exploitation of flexibility at ...

Iterative Rational Krylov Algorithm (IRKA) of [11] is an effective tool for tackling the H2-optimal model reduction problem. However, so far it has relied on a first-order state-space realization of the model-to-be-reduced. In this paper, by exploiting the Loewner-matrix approach for interpolation, we develop a new formulation of IRKA that only requires transfer function evaluations without acc...

In this paper, a new algorithm for system identification based on frequency response is presented. In this method, given a set of magnitudes and phases of the system transfer function in a set of discrete frequencies, a system of linear equations is derived which has a unique and exact solution for the coefficients of the transfer function provided that the data is noise-free and the degrees of...

In this paper, a new algorithm for system identification based on frequency response is presented. In this method, given a set of magnitudes and phases of the system transfer function in a set of discrete frequencies, a system of linear equations is derived which has a unique and exact solution for the coefficients of the transfer function provided that the data is noise-free and the degrees of...