Ricerc@Sapienza

The nonlinear dynamic response of short cables with a tip mass subject to base excitations and undergoing primary resonance is investigated via experimental tests and by employing an ad hoc nonlinear mechanical model. The considered cables are made of several strands of steel wires twisted into a helix forming composite ropes in a pattern known as ’laid ropes’. Such short span ropes exhibit a hysteretic behavior due to the inter-wire frictional sliding.

In accordance with national and international regulations, the energy usage and emissions of buildings need to be reduced. Both new constructions and retrofit actions should consider the strict requirements of a more sustainable built environment. In many cases, passive and active strategies are only added to the project after an initial conceptual design of the building has already been drawn up, thus limiting their effective integration into the construction as well as their efficacy.

The energy requalification of existing buildings entails the fulfillment of different, often conflicting, criteria, such as the reduction of the specific annual energy demand, the containment of the construction costs, the decrease in the annual energy operating cost and the reduction of climate-change gas emissions. Therefore, optimization methods based on the application of computational algorithms are essential to determine solutions that meet multi-objective criteria and so highly optimized to be on the Pareto frontier.

The paper describes a method based on virtual reality tools to achieve the attitude determination of an orbiting object using lightcurve measurements. A virtual model of the orbiting object is propagated in order to reproduce its lightcurve. The differences between the real and simulated lightcurves is used as the cost function to be minimized through a multiobjective genetic algorithm. Lightcurve measurements in different spectral bands, both with monostatic and multistatic optical observations can be used.

Since ancient times, lubricants have been applied in different fields of technology and, from the very beginning, there has been a wide interest on improving some of their physical-chemical properties. The turning point in the development of lubricants came in the twentieth century, when modern synthetic ester base fluids were realized. In fact, with respect to “natural” lubricants (fats and mineral oils), they can be modified in order to optimize some specific technological properties; in particular, it is desirable that they present high viscosity index and a low pour point.

The worldwide power grid can be thought as a System of Systems deeply embedded in a time-varying, non-deterministic and stochastic environment. The availability of ubiquitous and pervasive technology about heterogeneous data gathering and information processing in the Smart Grids allows new methodologies to face the challenging task of fault detection and modeling. In this study, a fault recognition system for Medium Voltage feeders operational in the power grid in Rome, Italy, is presented.

The efficient integration of Renewable Energy Sources (RES) in the actual electrical grid has gained recently a high attention in the Smart Grids (SGs) research topic. The evolution of existing electric distribution networks into SGs can be accomplished gradually and conveniently through the installation of local grid-connected Microgrids (MGs), usually installed nearby the RESs and provided by Energy Storage Systems (ESSs). Each MG is in charge to manage connected RES, assuring the local power demand, as well as the safety and stability of the electric grid.

In Italy, wind solutions for the generation of electricity from renewable energy sources (RES-E) have been
widely adopted, especially in regions with good geo-climatic conditions. In the last years, the need to limit the
soil sealing has resulted in a great deal of attention being given to the implementation of RES-E energy policies
integrated with the existing urban properties.
In this paper, the authors have pursued two main objectives. The first is an analysis of the financial feasibility

Software-Defined Networking (SDN) is a new networking paradigm that is attracting the attention of the research community due to the flexibility provided by the separation between data and control planes. In particular, the SDN scenario introduces new aspects to be considered when formulating the energy-aware routing problem, such as the reconfiguration cost of flow tables. In this paper we introduce and investigate the problem of minimizing the power consumption of an SDN network while also reducing the number of rules that have to be modified in the flow tables of SDN nodes.

In this paper, the performance appropriateness of population-based metaheuristics for immunotherapy protocols is investigated on a comparative basis while the goal is to stimulate the immune system to defend against cancer. For this purpose, genetic algorithm and particle swarm optimization are employed and compared with modern method of Pontryagin's minimum principle (PMP).