130,524 research outputs found
Definitely Maybe : What's the Real Obama Signature on US Defence Policies?
No full textSeveral challenges that Obama faced in his first four years in office remain at the top of his agenda. Yet, the circumstances in which they are to be met are considerably changed. Obama’s second term foreign policy is suffering from a number of domestic and international constraints: The American public is tired of war, the economic slow-down leads to severe cuts on defense budget, austerity in Europe is negatively affecting NATO international commitment and Obama's support abroad and at home is lessened.
This paper explores how the Obama administration is coping with these constraints. It focuses on elements of evolution and continuity in U.S. foreign and security policies in four policy area: (a) strategic planning; (b) the strategic shift toward Asia; (c) mission in Afghanistan; and (d) war on terrorism and the use of drones
Favourite violin and piano duets / edited by D Carati
No full textViolinFederal music books ; no. 50Publisher's no. : 251
No easy way out : origins and consequences of NATO’s failure in Afghanistan
No full textBy the end of 2014 the ISAF mission in Afghanistan will come to an end and a new NATO mission – Resolute Support – will be launched next year. In three years, the military presence in Afghanistan has dramatically diminished from 140,000 troops in 2011 to 52,000 (February 2014) and will be reduced to 12/13,000 in 2015. ISAF withdrawal and, more generally, the drastic reduction of the military presence are not motivated by a clear-cut improvement in the country, neither in the socio-economic and institutional sphere nor in the security conditions.
The paper explores the reasons why the international intervention has not attained the goals set for it. It investigates mistakes and limits of the strategic approach behind the military intervention since 2001 focusing on: (a) the consequences of the initial lack of distinction between the Taliban regime and al-Qaeda militants, (b) problems of coordination and competing visions between the US-lead mission Enduring Freedom and ISAF, (c) the ideological side of the war on terror which complicated the regional context and failed to engage regional actors in Afghanistan; (d) shortcomings and limited results of the Af-Pak Strategy
Color Constancy Effects Measurement of the Retinex Theory
No full textUnderstanding chromatic adaptation is a necessary step to solve the color constancy problem for a variety of application purposes. Retinex theory justifies chromatic adaptation, as well as other color illusions, on visual perception principles. Based on the above theory, we have derived an algorithm to solve the color constancy problem and to simulate chromatic adaptation. The evaluation of the results depends on the kind of applications considered. Since our purpose is to contribute to the problem of color rendering on computer system display for photorealistic image synthesis, we have devised a specific test approach. A virtual 'Mondrian' patchwork has been created by applying a rendering algorithm with a photorealistic light model to generate images under different light sources. Trichromatic values of the computer generated patches are the input data for the Retinex algorithm, which computes new color corrected patches. The Euclidean distance in CIELAB space, between the original and Retinex color corrected trichromatic values, has been calculated, showing that the Retinex computational model is very well suited to solve the color constancy problem without any information on the illuminant spectral distribution
Boundary effects on the dynamics of chains of coupled oscillators
No full textWe study the dynamics of a chain of coupled particles subjected to a restoring force (Klein–Gordon lattice) in the cases of either periodic or Dirichlet boundary conditions. Precisely, we prove that, when the initial data are of small amplitude and have a long wavelength, the main part of the solution is interpolated by a solution of the nonlinear Schrödinger equation, which in turn has the property that its Fourier coefficients decay exponentially. The first order correction to the solution has Fourier coefficients that decay exponentially in the periodic case, but only as a power in the Dirichlet case. In particular our result allows one to explain the numerical computations of the paper (Bambusi et al 2007 Phys. Lett. A)
An Averaging Theorem for FPU in the Thermodynamic Limit
No full textConsider an FPU chain composed of N≫1 particles, and endow the phase space with the Gibbs measure corresponding to a small temperature β^(-1). Given a fixed K , we construct K packets of normal modes whose energies are adiabatic invariants (i.e., are approximately constant for times of order β^(1−a), a>0 ) for initial data in a set of large measure. Furthermore, the time autocorrelation function of the energy of each packet does not decay significantly for times of order β. The restrictions on the shape of the packets are very mild. All estimates are uniform in the number N of particles and thus hold in the thermodynamic limit N→∞ , β>0
The nonlinear Schrodinger equation as a resonant normal form
No full textAveraging theory is used to study the dynamics of dispersive equations taking the nonlinear Klein Gordon equation on the line as a model problem: For approximatively monochromatic initial data of amplitude E, we show that the corresponding solution consists of two non interacting wave packets, each one being described by a nonlinear Schrodinger equation. Such solutions are also proved to be stable over times of order 1/epsilon(2). We think that this approach puts into a new light the problem of obtaining modulations equations for general dispersive equations. The proof of our results requires a new use of normal forms as a tool for constructing approximate solutions
The nonlinear Schrödinger equation as a resonant normal form
No full textAveraging theory is used to study the dynamics of dispersive equations taking the nonlinear Klein Gordon equation on the line as a model problem. For approximatively monochromatic initial data of amplitude , we show that the corresponding solution consists of two non interacting wave packets, each one being described by a nonlinear Schr\"odinger equation. Such solutions are also proved to be stable over times of order . We think that this approach puts into a new light the problem of obtaining modulations equations for general dispersive equations. The proof of our results requires a new use of normal forms as a tool for constructing approximate solutions
Freer when constrained? Italy and transatlantic relations during the cold war
No full textSince the end of WWII, Atlanticism has always been one of the lodestars of Italy’s foreign policy. Although the country’s relations with the U.S. have never been disputed, its degree of autonomy from the Transatlantic partnership has changed over the years. This article delves into such changes starting from a counter-intuitive analytical framework based on the neo-realist theory of International Relations. Such perspective can help explain Italy’s unexpected
autonomy in certain periods of the cold war. Accordingly, the article reexamines two historical events: Italy’s elusive conduct during the negotiations
of the Non-Proliferation Treaty (NPT) and the Achille Lauro/Sigonella crisis in 1985
Theoretical thermodynamic analysis of a closed-cycle process for the conversion of heat into electrical energy by means of a distiller and an electrochemical cell
No full textWe analyse a device aimed at the conversion of heat into electrical energy,
based on a closed cycle in which a distiller generates two solutions at
different concentrations, and an electrochemical cell consumes the
concentration difference, converting it into electrical current. We first study
an ideal model of such a process. We show that, if the device works at a single
fixed pressure (i.e. with a ``single effect''), then the efficiency of the
conversion of heat into electrical power can approach the efficiency of a
reversible Carnot engine operating between the boiling temperature of the
concentrated solution and that of the pure solvent. When two heat reservoirs
with a higher temperature difference are available, the overall efficiency can
be incremented by employing an arrangement of multiple cells working at
different pressures (``multiple effects''). We find that a given efficiency can
be achieved with a reduced number of effects by using solutions with a high
boiling point elevation.Comment: The following article has been submitted to Journal of Renewable and
Sustainable Energy. After it is published, it will be found at
http://scitation.aip.org/content/aip/journal/jrs
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