Search results for "ESA"

Dall'immagine all'etica: riflessioni sull'Abitare urbano

2012

Dall’immagine all’etica. Riflessioni sull’abitare urbano è un libro nel quale Antonello Russo espone in modo sintetico ed efficace le sue convinzioni sull’architettura, disegnando un convincente panorama teorico. Con una prosa nella quale la chiarezza argomentativa si unisce a una non indifferente capacità narrativa, l’autore costruisce un sistema dinamico di principi disciplinari i quali, muovendo da un approccio razionale, includono via via alcuni dei tanti materiali suggeriti dal contesto, nonché una serie di temi e di motivi che scaturiscono da letture interscalari del mondo fisico. Letture che rendono complesso il paradigma della ragione conferendo ad esso un’attitudine ad aderire alle…

The Economic Impact of Restricted Water Supply: a Computable General Equilibrium Analysis

2007

Water problems are typically studied at the level of the river catchment. About 70% of all water is used for agriculture, and agricultural products are traded internationally. A full understanding of water use is impossible without understanding the international market for food and related products, such as textiles. The water embedded in commodities is called virtual water. Based on a general equilibrium model, we offer a method for investigating the role of water resources and water scarcity in the context of international trade. We run five alternative scenarios, analyzing the effects of water scarcity due to reduced availability of groundwater. This can be a consequence of physical con…

Appearances of pseudo-bosons from Black-Scholes equation

2016

It is a well known fact that the Black-Scholes equation admits an alternative representation as a Schr\"odinger equation expressed in terms of a non self-adjoint hamiltonian. We show how {\em pseudo-bosons}, linear or not, naturally arise in this context, and how they can be used in the computation of the pricing kernel.

A secular equation for the Jacobian matrix of certain multispecies kinematic flow models

2010

Estimates for the constants of Landau and Lebesgue via some inequalities for the Wallis ratio

2014

New dimension indices for the characterization of the solvent-accessible surface

2001

An analysis of Ralston's quadrature

1987

Ralston's quadrature achieves higher accuracy in composite rules than analogous Newton-Cotes or Gaussian formulas. His rules are analyzed, computable expressions for the weights and knots are given, and a more suitable form of the remainder is derived.

Residuenabschätzung für Polynom-Nullstellen mittels Lagrange-Interpolation

1970

If, for each zero of a polynomial, an approximation is known, estimates for the errors of these approximations are given, based on the evaluation of the polynomial at these points. The procedure can be carried over to the case of multiple roots and root clusters using derivatives up to the orderk - 1, wherek is the multiplicity of the cluster.

On the Computational Complexity of Binary and Analog Symmetric Hopfield Nets

2000

We investigate the computational properties of finite binary- and analog-state discrete-time symmetric Hopfield nets. For binary networks, we obtain a simulation of convergent asymmetric networks by symmetric networks with only a linear increase in network size and computation time. Then we analyze the convergence time of Hopfield nets in terms of the length of their bit representations. Here we construct an analog symmetric network whose convergence time exceeds the convergence time of any binary Hopfield net with the same representation length. Further, we prove that the MIN ENERGY problem for analog Hopfield nets is NP-hard and provide a polynomial time approximation algorithm for this p…

Descriptive Complexity, Lower Bounds and Linear Time

1999

This paper surveys two related lines of research: Logical characterizations of (non-deterministic) linear time complexity classes, and non-expressibility results concerning sublogics of existential second-order logic. Starting from Fagin’s fundamental work there has been steady progress in both fields with the effect that the weakest logics that are used in characterizations of linear time complexity classes are closely related to the strongest logics for which inexpressibility proofs for concrete problems have been obtained. The paper sketches these developments and highlights their connections as well as the obstacles that prevent us from closing the remaining gap between both kinds of lo…