Search results for " method"

Enhancing Metastability by Dissipation and Driving in an Asymmetric Bistable Quantum System.

2018

The stabilizing effect of quantum fluctuations on the escape process and the relaxation dynamics from a quantum metastable state are investigated. Specifically, the quantum dynamics of a multilevel bistable system coupled to a bosonic Ohmic thermal bath in strong dissipation regime is analyzed. The study is performed by a non-perturbative method based on the real-time path integral approach of the Feynman-Vernon influence functional. We consider a strongly asymmetric double well potential with and without a monochromatic external driving, and with an out-of-equilibrium initial condition. In the absence of driving we observe a nonmonotonic behavior of the escape time from the metastable regi…

Riflessioni metodologiche geografiche sul quartiere. Tra frontiere invisibili e barriere visibili

2012

Saber y racionalidad en el pensamiento de María Zambrano

2011

El artículo estudia la articulación de la racionalidad y sus límites con la idea moderna de método, y con la expresión poética de las dimensiones no conceptualizables de la experiencia en la obra de M. Zambrano. Como consecuencia, se opone a aquellas interpretaciones de la “razón poética” que acentúan su lado oscuro en detrimento de su utilización de procedimientos racionales.

Numerical treatment of radiation processes in the internal shocks of magnetized relativistic outflows

2017

Los blázares son un tipo de núcleo activo de galaxia (AGN, por sus siglas en inglés) que se encuentran entre los objetos astrofísicos más energéticos y violentos, a la par de los brotes de rayos gamma (GRB por sus siglas en inglés). Los procesos físicos y, en particular, el escenario del chorro relativista en el que se genera la radiación ultraenergética detectada por observatorios terrestres y en órbita, han conseguido atraer la atención e interés de los astrónomos y astrofísicos desde su descubrimiento. En la presente tesis investigamos el modelo de choques internos (IS) cuya hipótesis consta del choque de dos capas de plasma con geometría cilíndrica, formando dos ondas de choque que atra…

Planning as evolution: radical pedagogy, creative methods and urban research

2022

Beyond reductionist thought, looking at a theoretical framework that embrace a complex dimension of knowledge, the urban planning discipline is going through a radical change. An attitude well expressed by a large group of intellectuals who recognize the fragility of the discipline and re-think themselves in opposition to the excess of specialization of the modern world to grasp the vital interconnection between things, the intersection spaces, on disciplinary boundaries, where concepts become images, symbols, practices, processes. In this ongoing change of paradigm, sensitive approaches and aesthetic rationalities arouse interest within urban and territorial studies. Starting from the inte…

Determinants of current account balances

2011

Generalized wave propagation problems and discrete exterior calculus

2018

We introduce a general class of second-order boundary value problems unifying application areas such as acoustics, electromagnetism, elastodynamics, quantum mechanics, and so on, into a single framework. This also enables us to solve wave propagation problems very efficiently with a single software system. The solution method precisely follows the conservation laws in finite-dimensional systems, whereas the constitutive relations are imposed approximately. We employ discrete exterior calculus for the spatial discretization, use natural crystal structures for three-dimensional meshing, and derive a “discrete Hodge” adapted to harmonic wave. The numerical experiments indicate that the cumulat…

ENSEMBLE METHODS FOR RANKING DATA

2017

The last years have seen a remarkable flowering of works about the use of decision trees for ranking data. As a matter of fact, decision trees are useful and intuitive, but they are very unstable: small perturbations bring big changes. This is the reason why it could be necessary to use more stable procedures, as ensemble methods, in order to find which predictors are able to explain the preference structure. In this work ensemble methods as BAGGING and Random Forest are proposed, from both a theoretical and computational point of view, for deriving classification trees when ranking data are observed. The advantages of these procedures are shown through an example on the SUSHI data set.

Ensemble methods for ranking data with and without position weights

2020

The main goal of this Thesis is to build suitable Ensemble Methods for ranking data with weights assigned to the items’positions, in the cases of rankings with and without ties. The Thesis begins with the definition of a new rank correlation coefficient, able to take into account the importance of items’position. Inspired by the rank correlation coefficient, τ x , proposed by Emond and Mason (2002) for unweighted rankings and the weighted Kemeny distance proposed by García-Lapresta and Pérez-Román (2010), this work proposes τ x w , a new rank correlation coefficient corresponding to the weighted Kemeny distance. The new coefficient is analized analitically and empirically and represents the main…

Enhanced Customer Cooperation : Experiences with cooperative compliance in Finland

2018

This report examines the experiences with a collaborative compliance project – Enhanced Customer Cooperation (ECC) – introduced by the Finnish Tax Administration. The ECC was introduced by the Large Taxpayers’ Unit of the Finnish Tax Administration at the beginning of 2013, and it ran as a pilot until the end of 2015. Since the start of 2016, the ECC has been a part of the permanent operations of the Large Taxpayers’ Unit. Based on the interviews with tax officers, corporations participating in the ECC and tax lawyers and tax consultants, the ECC is bringing about a cultural change in the administrative practices and ways of communicating between tax authorities and taxpayers. In general, t…