Structure-preserving desynchronization of minority games

Perfect synchronicity in N-player games is a useful theoretical dream, but communication delays are inevitable and may result in asynchronous interactions. Some systems such as financial markets are asynchronous by design, and yet most theoretical models assume perfectly synchronized actions. We propose a general method to transform standard models of adaptive agents into asynchronous systems while preserving their global structure under some conditions. Using the minority game as an example, we find that the phase and fluctuations structure of the standard game subsists even in maximally asynchronous deterministic case, but that it disappears if too much stochasticity is added to the temporal structure of interaction. Allowing for heterogeneous communication speeds and activity patterns gives rise to a new information ecology that we study in detail

On the benthic Ekman layer

A review of the standard model of the benthic Ekman layer is presented and reformulated in terms of relative vorticity in place of horizontal current. In this context, the possibility to use mixed boundary conditions to model this layer is explored. The related model solutions can be cast into two main groups: the first is a generalization of the classical Ekman result, while the second one has some unexpected features which are problematic with respect to the Ekman pumping process. An investigation on the finite amplitude stability via the Lyapunov method shows that solutions belonging to the first group are stable while, in the second group, solutions are unstable. This fact poses a physical constraint to the set of the admissible boundary conditions. Finally, a connection between mass transport and boundary condition at the sea floor is numerically investigated

Influence of vineyard inter-row management and clone on 'Sauvignon Blanc' performance in Friuli Venezia Giulia (north-eastern Italy)

The vineyard inter-row management affects grapevine vegetative and bunch health status, as well as yield and grape quality parameters. Several studies assessed that cover-cropped inter-row in place of soil tillage often reduced plant vigour and yield but positively contributed to vineyard ecosystem services and, to a lower extent, to grape quality. In 2013 and 2014, two inter-row management strategies, i.e. soil tillage and mowing of spontaneous cover crops, were compared in an organic vineyard in north-eastern Italy and cultivated with 'Sauvignon Blanc' (Vitis vinifera L.), clones R3 and 297. In particular, the effects of tillage and mowing treatments on grapevine vegetative and bunch health status, yield and grape quality were evaluated. The vegetative parameters were lower in the mowing treatment than in the tillage one and in clone R3 compared to 297. The incidence of Botrytis cinerea was higher in the tillage treatment than in the mowing one and in clone 297 compared to R3. A significant reduction of the yield and bunch weight was ascertained in the mowing treatment, and these parameters were higher for clone 297 compared to clone R3. Titratable acidity was significantly higher in the tillage treatment than in the mowing one and in clone 297 compared to R3. Moreover, hue of berry skin was qualitatively better in the tillage treatment than in the mowing one. In the pedo-climatic conditions of Friuli Venezia Giulia (north-eastern Italy), the management of the vineyard inter-row with spontaneous cover crops proved to be effective to manage grapevine vigour, reducing yield and improving quality of the grapes during maturation

Statistical mechanics of the mixed majority-minority game with random external information

We study the asymptotic macroscopic properties of the mixed majority-minority game, modeling a population in which two types of heterogeneous adaptive agents, namely ``fundamentalists'' driven by differentiation and ``trend-followers'' driven by imitation, interact. The presence of a fraction f of trend-followers is shown to induce (a) a significant loss of informational efficiency with respect to a pure minority game (in particular, an efficient, unpredictable phase exists only for f<1/2), and (b) a catastrophic increase of global fluctuations for f>1/2. We solve the model by means of an approximate static (replica) theory and by a direct dynamical (generating functional) technique. The two approaches coincide and match numerical results convincingly.Comment: 19 pages, 3 figure

Structure-preserving desynchronization of minority games

Perfect synchronicity in $N$-player games is a useful theoretical dream, but communication delays are inevitable and may result in asynchronous interactions. Some systems such as financial markets are asynchronous by design, and yet most theoretical models assume perfectly synchronized actions. We propose a general method to transform standard models of adaptive agents into asynchronous systems while preserving their global structure under some conditions. Using the Minority Game as an example, we find that the phase and fluctuations structure of the standard game subsists even in maximally asynchronous deterministic case, but that it disappears if too much stochasticity is added to the temporal structure of interaction. Allowing for heterogeneous communication speeds and activity patterns gives rise to a new information ecology that we study in details.Comment: 6 pages, 7 figures. New version removed a section and found a new phase transitio

Overview of the FTU results

Since the 2018 IAEA FEC Conference, FTU operations have been devoted to several experiments covering a large range of topics, from the investigation of the behaviour of a liquid tin limiter to the runaway electrons mitigation and control and to the stabilization of tearing modes by electron cyclotron heating and by pellet injection. Other experiments have involved the spectroscopy of heavy metal ions, the electron density peaking in helium doped plasmas, the electron cyclotron assisted start-up and the electron temperature measurements in high temperature plasmas. The effectiveness of the laser induced breakdown spectroscopy system has been demonstrated and the new capabilities of the runaway electron imaging spectrometry system for in-flight runaways studies have been explored. Finally, a high resolution saddle coil array for MHD analysis and UV and SXR diamond detectors have been successfully tested on different plasma scenarios

Thin cylinder-bore coatings for aluminum combustion engines

Questo articolo presenta le problematiche e le possibili soluzioni riguardanti la protezione della superficie interna dei cilindri di motori ad accensione comandata in lega leggera. E' necessario l'uso di rivestimenti resistenti alll'attrito e in grado di ridurre la possibilit\ue0 di impuntamento e d'incollaggio delle fasce, specie in prossimit\ue0 del PMS. Oltre alla camicia in ghisa, si stanno sviluppando rivestimenti sottili, caratterizzati da peso ridotto, scarsa sensibilit\ue0 alle deformazioni termiche e una buona ritenzione di lubrificante. E' richiesta un'adeguata ottimizzazione delle variabili in gioco: il materiale, la finitura, la preparazione, il metodo di applicazione, il tipo di fasce di tenuta e le tolleranze. Dopo l'illustrazione dello stato dell'arte dei rivestimenti, sono descritte le nostre metodologie di test e riportati i primi risulatti relativi all'attivit\ue0 di svuiluppo di una tecnologia adatta anche a motori ad alte prestazioni