On the micro-to-macro limit for first-order traffic flow models on networks

Connections between microscopic follow-the-leader and macroscopic fluid-dynamics traffic flow models are already well understood in the case of vehicles moving on a single road. Analogous connections in the case of road networks are instead lacking. This is probably due to the fact that macroscopic traffic models on networks are in general ill-posed, since the conservation of the mass is not sufficient alone to characterize a unique solution at junctions.

Parallel Quasi Exhaustive Search of Optimal Asset Allocation for Pension Funds

We present a solution based on a suitable combination of heuristics and parallel processing techniques for finding the best allocation of the financial assets of a pension fund, taking into account all the specific rules of the fund. We compare the values of an objective function computed with respect to a large set (thousands) of possible scenarios for the evolution of the Net Asset Value (NAV) of the share of each asset class in which the financial capital of the fund is invested.

Handling obstacles in pedestrian simulations: Models and optimization

In this paper we are concerned with the simulation of crowds in built environments, where obstacles play a role in the dynamics and in the interactions among pedestrians. First of all, we review the state-of-the-art of the techniques for handling obstacles in numerical simulations. Then, we introduce a new modeling technique which guarantees both impermeability and opacity of the obstacles, and does not require ad hoc runtime interventions to avoid collisions.

Blending Brownian motion and heat equation

In this short communication we present an original way to couple the Brownian motion and the heat equation. More in general, we suggest a way for coupling the Langevin equation for a particle, which describes a single realization of its trajectory, with the associated Fokker-Planck equation, which instead describes the evolution of the particle's probability density function. Numerical results show that it is indeed possible to obtain a regularized Brownian motion and a Brownianized heat equation still preserving the global statistical properties of the solutions.

Gyroscope precession along bound equatorial plane orbits around a Kerr black hole

The precession of a test gyroscope along stable bound equatorial plane orbits around a Kerr black hole is analyzed, and the precession angular velocity of the gyro's parallel transported spin vector and the increment in the precession angle after one orbital period is evaluated. The parallel transported Marck frame which enters this discussion is shown to have an elegant geometrical explanation in terms of the electric and magnetic parts of the Killing-Yano 2-form and a Wigner rotation effect.

Scenes from the life of Beppo Levi

On the occasion of the 140th anniversary of the birth of the famous Italian mathematician Beppo Levi (1875-1961), we publish an interview with his daughter Emilia. We also recall his brother Eugenio Elia Levi, a well-known and brilliant mathematician whose life was cut short at the front during World War I. A brief outline of Beppo Levi's life is followed by an introduction to a letter that he wrote to the periodical Israel in 1919, in part regarding the foundation of the state of Israel. Finally, we publish an English translation of the letter in its entirety.

Turning ability analysis of a fully appended twin screw vessel by CFD. Part II: Single vs. twin rudder configuration

In the present paper, the analysis of the turning capability of the naval supply vessel presented in Part I (Broglia et al., 2015) is continued with different stern appendages, namely twin rudder and centreline skeg. The main purpose of the analysis is to assess the capability of an in-house CFD tool in capturing the different manoeuvring characteristics of the ship hulls; the test case is challenging, as the difference be- tween the two configurations lies in the complex flow structure related to rudder-propeller interactions. Moreover, although the twin rudder solution slightly improves the