In this paper, we test the spherical collapse of a viscous unified dark fluid (VUDF) which has constant adiabatic sound speed and show the nonlinear collapse forVUDF, baryons, and dark matter, which are important in forming the large-scale structure of our Universe. By varying the values of the model parameters α and ζ0, we discuss their effects on the nonlinear collapse of the VUDF model, and ...

The purpose of this paper is to study the description of power system QV curves by using the method of fuzzy modeling for analysis of voltage stability. Voltage instability of power system comes from increasing load rapidly, and causes bus voltage to drop. When voltage is out of control and it can be voltage collapse. The QV curve can identify voltage stability limit, and it determine robustnes...

Abstract After the 2018 collapse of Morandi highway bridge in Genova, new Italian guidelines (GL) were issued for prioritization safety evaluations and retrofit interventions on existing bridges. Among several novelties, GL introduced traffic load models (TLMs) which can be adopted bridges case noncompliant checks according to building code (NTC) provisions. In this study, a class simply suppor...

The public health measures implemented to limit the COVID-19 pandemic are likely affect economic inequalities. In this paper we first provide a theoretical framework analyse how income inequality contributes shaping trade-off between lockdown and contagion. Our empirical analysis on EU countries shows that is significantly increase poverty magnitude of change larger in more unequal countries. T...

We analyze here the issue of local versus the global visibility of a singularity that forms in gravitational collapse of a dust cloud, which has important implications for the weak and strong versions of the cosmic censorship hypothesis. We find conditions as to when a singularity will be only locally naked, rather than being globally visible, thus preseving the weak censorship hypothesis. The ...

Resilience is a challenging concept that is given many definitions and perspectives in the engineering infrastructure, systems engineering, and economic literatures. An emerging understanding of resilient systems is as a management principle or framework allowing for reconfiguration or adaptation in the face of threats or shocks. This is in contrast to the prevailing approach to engineered syst...