A new approach for transport network design and optimization

The solution of the transportation network optimization problem actually requires, in most cases, very intricate and powerful computer resources, so that it is not feasible to use classical algorithms. One promising way is to use stochastic search techniques. In this context, Genetic Algorithms (GAs) seem to be - among all the available methodologies- one of the most efficient methods able to approach transport network design and optimization. Particularly, this paper will focus the attention on the possibility of modelling and optimizing Public Bus Networks by means of GAs. In the proposed algorithm, the specific class of Cumulative GAs(CGAs) will be used for solving the first level of the network optimization problem, while a classical assignment model ,or alternatively a neural network approach ,will be adopted for the Fitness Function(FF) evaluation. CGAs will then be utilized in order to generate new populations of networks, which will be evaluated by means of a suitable software package. For each new solution some indicators will be calculated .A unique FF will be finally evaluated by means of a multicriteria method. Altough the research is still in a preliminary stage, the emerging first results concerning numerical cases show very good perspectives for this new approach. A test in real cases will also follow.

A composite indicator via hierarchical disjoint factor analysis for measuring the Italian football teams’ performances

In the last years, with the data revolution and the use of new technologies, phenomena are frequently described by a huge quantity of information useful for making strategical decisions. In the current ”big data” era, the interest of statistics into sports is increasing over the years, sportive and economic data are collected for all teams which use statistical analysis in order to improve their performances. For dealing with all this amount of information, an appropriate statistical analysis is needed. A priority is having statistical tools useful to synthesise the information arised from the data. Such tools are represented by composite indicators, that is, non-observable latent variables and linear combination of observed variables. The strategy of construction of a composite indicator used in this paper is based on a non-negative disjoint and hierarchical model for a set of quantitative variables. This is a factor model with a hierarchical struc- ture formed by factors associated to subsets of manifest variables with positive loadings. In this paper, a composite indicator for measuring the Italian football teams’ performances, in terms of sportive and economic variables, is proposed

Entanglement spectrum of random-singlet quantum critical points

The entanglement spectrum, i.e., the full distribution of Schmidt eigenvalues of the reduced density matrix, contains more information than the conventional entanglement entropy and has been studied recently in several many-particle systems. We compute the disorder-averaged entanglement spectrum, in the form of the disorder-averaged moments of the reduced density matrix, for a contiguous block of many spins at the random-singlet quantum critical point in one dimension. The result compares well in the scaling limit with numerical studies on the random XX model and is also expected to describe the (interacting) random Heisenberg model. Our numerical studies on the XX case reveal that the dependence of the entanglement entropy and spectrum on the geometry of the Hilbert space partition is quite different than for conformally invariant critical points.Comment: 11 pages, 10 figure

Second-hand smoke generated by combustion and electronic smoking devices used in real scenarios: ultrafine particle pollution and age-related dose assessment

Aerosol measurements were carried out in a model room where both combustion (conventional and hand-rolled cigarettes, a cigar and tobacco pipe) and non-combustion (e-cigarette and IQOS®) devices were smoked. The data were used to estimate the dose of particles deposited in the respiratory systems of individuals from 3 months to 21 years of age using the multiple-path particle dosimetry (MPPD) model. Regardless of the smoking device, the highest doses were received by infants, which reached 9.88 ×108 particles/kg bw during a cigar smoking session. Moreover, 60% to 80% of the particles deposited in the head region of a 3-month-old infant were smaller than 100 nm and could be translocated to the brain via the olfactory bulb. The doses due to second-hand smoke from electronic devices were significantly lower, below 1.60 ×108 particles/kg bw, than those due to combustion devices. Dosimetry estimates were 50% to 110% higher for IQOS® than for e-cigarettes

A new approach for transport network design and optimization

The solution of the transportation network optimization problem actually requires, in most cases, very intricate and powerful computer resources, so that it is not feasible to use classical algorithms. One promising way is to use stochastic search techniques. In this context, Genetic Algorithms (GAs) seem to be - among all the available methodologies- one of the most efficient methods able to approach transport network design and optimization. Particularly, this paper will focus the attention on the possibility of modelling and optimizing Public Bus Networks by means of GAs. In the proposed algorithm, the specific class of Cumulative GAs(CGAs) will be used for solving the first level of the network optimization problem, while a classical assignment model ,or alternatively a neural network approach ,will be adopted for the Fitness Function(FF) evaluation. CGAs will then be utilized in order to generate new populations of networks, which will be evaluated by means of a suitable software package. For each new solution some indicators will be calculated .A unique FF will be finally evaluated by means of a multicriteria method. Altough the research is still in a preliminary stage, the emerging first results concerning numerical cases show very good perspectives for this new approach. A test in real cases will also follow

The impact of the Geometric Correction Scheme on MEG functional topology at rest

Spontaneous activity is correlated across brain regions in large scale networks (RSN) closely resembling those recruited during several behavioral tasks and characterized by functional specialization and dynamic integration. Specifically, MEG studies revealed a set of central regions (dynamic core) possibly facilitating communication among differently specialized brain systems. However, source projected MEG signals, due to the fundamentally ill-posed inverse problem, are affected by spatial leakage, leading to the estimation of spurious, blurred connections that may affect the topological properties of brain networks and their integration. To reduce leakage effects, several correction schemes have been proposed including the Geometric Correction Scheme (GCS) whose theory, simulations and empirical results on topography of a few RSNs were already presented. However, its impact on the estimation of fundamental graph measures used to describe the architecture of interactions among brain regions has not been investigated yet. Here, we estimated dense, MEG band-limited power connectomes in theta, alpha, beta, and gamma bands from 13 healthy subjects (all young adults). We compared the connectivity and topology of MEG uncorrected and GCS-corrected connectomes. The use of GCS considerably reorganized the topology of connectivity, reducing the local, within-hemisphere interactions mainly in the beta and gamma bands and increasing across-hemisphere interactions mainly in the alpha and beta bands. Moreover, the number of hubs decreased in the alpha and beta bands, but the centrality of some fundamental regions such as the Posterior Cingulate Cortex (PCC), Supplementary Motor Area (SMA) and Middle Prefrontal Cortex (MPFC) remained strong in all bands, associated to an increase of the Global Efficiency and a decrease of Modularity. As a comparison, we applied orthogonalization on connectomes and ran the same topological analyses. The correlation values were considerably reduced, and orthogonalization mainly decreased local within-hemisphere interactions in all bands, similarly to GCS. Notably, the centrality of the PCC, SMA and MPFC was preserved in all bands, as for GCS, together with other hubs in the posterior parietal regions. Overall, leakage correction removes spurious local connections, but confirms the role of dynamic hub regions, specifically the anterior and posterior cingulate, in integrating information in the brain at rest

Reference intervals for urinary cotinine levels and the influence of sampling time and other predictors on its excretion among italian schoolchildren

(1) Background: Environmental Tobacco Smoke (ETS) exposure remains a public health problem worldwide. The aims are to establish urinary (u-) cotinine reference values for healthy Italian children, to evaluate the role of the sampling time and of other factors on children’s u-cotinine excretion. (2) Methods: A cross-sectional study was performed on 330 children. Information on participants was gathered by a questionnaire and u-cotinine was determined in two samples for each child, collected during the evening and the next morning. (3) Results: Reference intervals (as the 2.5th and 97.5th percentiles of the distribution) in evening and morning samples were respectively equal to 0.98-4.29 and 0.91-4.50 µg L-1(ETS unexposed) and 1.39-16.34 and 1.49-20.95 µg L-1(ETS exposed). No statistical differences were recovered between median values found in evening and morning samples, both in ETS unexposed and exposed. Significant predictors of u-cotinine excretions were ponderal status according to body mass index of children (β = 0.202; p-value = 0.041 for evening samples; β = 0.169; p-value = 0.039 for morning samples) and paternal educational level (β = -0.258; p-value = 0.010; for evening samples; β = -0.013; p-value = 0.003 for morning samples). (4) Conclusions: The results evidenced the need of further studies for assessing the role of confounding factors on ETS exposure, and the necessity of educational interventions on smokers for rising their awareness about ETS

Quantum Quench in the Transverse Field Ising Chain

We consider the time evolution of observables in the transverse field Ising chain (TFIC) after a sudden quench of the magnetic field. We provide exact analytical results for the asymptotic time and distance dependence of one- and two-point correlation functions of the order parameter. We employ two complementary approaches based on asymptotic evaluations of determinants and form-factor sums. We prove that the stationary value of the two-point correlation function is not thermal, but can be described by a generalized Gibbs ensemble (GGE). The approach to the stationary state can also be understood in terms of a GGE. We present a conjecture on how these results generalize to particular quenches in other integrable models.Comment: 4 pages, 1 figur

An innovative numerical approach for railway rolling noise forecast

In recent years there has been a growing worldwide development of rail transport, mainly due to technological innovations both on armaments and on rail vehicles. Such technological issue focused almost parallel on two main fronts: on one hand the performance enhancement and on the other side the internal comfort. This technology advancement has been driven mainly by the need to move goods and passengers over long distances in a short time, making it the safest transportation system in the world thanks also to the latest monitoring systems, of which European Community is undoubtedly one of the major leaders. The passenger transport has introduced problems related to comfort: traveling so fast is the main goal so long as it is comfortable and safe. One of the requirements that mostly turned out to be significant and sometimes more difficult to satisfy is that regarding acoustic comfort and environmental impact. As known, the regulations become with the passage of time more and more stringent, and every company that wants to operate in this area is required to respect them. The acoustic comfort improvement implies the intervention as much as possible focused on noise sources, which in this case are constituted by: electric motor, pantograph, wheel-rail contact. In such research framework, the authors focused on determination of a simple, but at the same time reliable, method for radiated sound power assessment in the wheel-rail contact due to combined wheel-rail roughness in order to reduce the environmental impact of this type of transmission system. Targeted analysis were implemented in an efficient numerical investigation in MSC NASTRAN® and ACTRAN® environments providing the necessary vibro-acoustic parameters as input data for the further definition of the wheel-rail interaction force by a MATLAB® customized tool, once known the roughness profile