Search results for "metodi"

A class of label-correcting methods for the K shortest paths problem

2001

In this paper we deal with the problem of finding the first K shortest paths from a single origin node to all other nodes of a directed graph. In particular, we define the necessary and sufficient conditions for a set of distance label vectors, on the basis of which we propose a class of methods which can be viewed as an extension of the generic label-correcting method for solving the classical single-origin all-destinations shortest path problem. The data structure used is characterized by a set of K lists of candidate nodes, and the proposed methods differ in the strategy used to select the node to be extracted at each iteration. The computational results show that: 1. some label-correct…

Polynomial method to study the entanglement of pure N-qubit states

2009

We present a mapping which associates pure N-qubit states with a polynomial. The roots of the polynomial characterize the state completely. Using the properties of the polynomial we construct a way to determine the separability and the number of unentangled qubits of pure N-qubit states.

Sequential deconfinement in 3d N=2 gauge theories

2021

We consider 3d N = 2 gauge theories with fundamental matter plus a single field in a rank-2 representation. Using iteratively a process of "deconfinement" of the rank-2 field, we produce a sequence of Seiberg-dual quiver theories. We detail this process in two examples with zero superpotential: Usp(2N) gauge theory with an antisymmetric field and U(N) gauge theory with an adjoint field. The fully deconfined dual quiver has N nodes, and can be interpreted as an Aharony dual of theories with rank-2 matter. All chiral ring generators of the original theory are mapped into gauge singlet fields of the fully deconfined quiver dual.

E-tourism economics: Editorial for the special issue

2019

Physical fitness and motor coordination monitoring during enriched sport activities in a sample of children living in Europe. The Esa Program

2018

Enriched Sport Activities Program (ESA) is an Evidence-based Practice Exercise Program cofounded by the Erasmus+ Programme of the European Union (Key action:Sport - 579661-EPP1-2016-2-IT-SPO-SCP). It aims to enhance social inclusion, equal opportunities and psycho-physical well being in school-age children with typical development and special needs trough sport activities enriched by cognitive tasks. A multidisciplinary approach has been employed; in detail, health - and skills-related physical fitness components, as well as developmental psychology and neuroscience research are the theoretical basis to implement an evidence-based program suitable to increase sport compliance in 7 different…

An optimized system dynamics approach for a hotel chain management

2009

The proposed model consists of an integrated system dynamics-data envelopment analysis approach to value, in a dynamic framework, the effects over time of the policies implemented according to the relative efficiency analysis. Rooms’ price and competing facilities (the hedonics) are the decision variables to move in order to push the hotels towards a higher relative efficiency at the end of the observation periods. In fact, in competitive markets as tourism, hotels compete for money offering differentiated quality. Moreover, according to the microeconomic theory, a producer of differentiated goods is not a price taker but a price maker. Therefore, we assume that the decision maker of the ho…

Pricing the Option to Surrender in Incomplete Markets

2010

New international accounting standards require insurers to reflect the value of embedded options and guarantees in their products. Pricing techniques based on the Black and Scholes paradigm are often used; however, the hypotheses underneath this model are rarely met. We propose a framework that encompasses the most known sources of incompleteness. We show that the surrender option, joined with a wide range of claims embedded in insurance contracts, can be priced through our tool, and deliver hedging portfolios to mitigate the risk arising from their positions. We provide extensive empirical analysis to highlight the effect of incompleteness on the fair value of the option.

Do firms share the same functional form of their growth rate distribution? A statistical test

2014

We introduce a new statistical test of the hypothesis that a balanced panel of firms have the same growth rate distribution or, more generally, that they share the same functional form of growth rate distribution. We applied the test to European Union and US publicly quoted manufacturing firms data, considering functional forms belonging to the Subbotin family of distributions. While our hypotheses are rejected for the vast majority of sets at the sector level, we cannot rejected them at the subsector level, indicating that homogenous panels of firms could be described by a common functional form of growth rate distribution.

Financial development and intergenerational education mobility

2018

Using years of education as a measure of status, we study the relationship between financial development and intergenerational mobility, focusing on human capital investments boosted by financial deepening. We consider a set of indices to capture different components of the overall intergenerational education mobility. Using a sample of 39 countries, we find that financial development is related to structural mobility but not to exchange mobility. In particular, while we detect an inverted U-shaped relationship between financial development and structural mobility, we do not find any significant relationship with exchange mobility. Keywords: Intergenerational mobility, Financial development…

Insurance fraud detection: A statistically validated network approach

2022

Fraud is a social phenomenon, and fraudsters often collaborate with other fraudsters, taking on different roles. The challenge for insurance companies is to implement claim assessment and improve fraud detection accuracy. We developed an investigative system based on bipartite networks, highlighting the relationships between subjects and accidents or vehicles and accidents. We formalize filtering rules through probability models and test specific methods to assess the existence of communities in extensive networks and propose new alert metrics for suspicious structures. We apply the methodology to a real database-the Italian Antifraud Integrated Archive-and compare the results to out-of-sam…