Poisson-Nijenhuis structures on quiver path algebras

We introduce a notion of noncommutative Poisson-Nijenhuis structure on the path algebra of a quiver. In particular, we focus on the case when the Poisson bracket arises from a noncommutative symplectic form. The formalism is then applied to the study of the Calogero-Moser and Gibbons-Hermsen integrable systems. In the former case, we give a new interpretation of the bihamiltonian reduction performed in [3].Comment: 23 page

A Note on the Automorphism Group of the Bielawski-Pidstrygach Quiver

We show that there exists a morphism between a group $\Gamma^{\mathrm{alg}}$ introduced by G. Wilson and a quotient of the group of tame symplectic automorphisms of the path algebra of a quiver introduced by Bielawski and Pidstrygach. The latter is known to act transitively on the phase space $\mathcal{C}_{n,2}$ of the Gibbons-Hermsen integrable system of rank 2, and we prove that the subgroup generated by the image of $\Gamma^{\mathrm{alg}}$ together with a particular tame symplectic automorphism has the property that, for every pair of points of the regular and semisimple locus of $\mathcal{C}_{n,2}$, the subgroup contains an element sending the first point to the second

How the Taxonomy of Products Drives the Economic Development of Countries

We introduce an algorithm able to reconstruct the relevant network structure on which the time evolution of country-product bipartite networks takes place. The significant links are obtained by selecting the largest values of the projected matrix. We first perform a number of tests of this filtering procedure on synthetic cases and a toy model. Then we analyze the bipartite network constituted by countries and exported products, using two databases for a total of almost 50 years. It is then possible to build a hierarchically directed network, in which the taxonomy of products emerges in a natural way. We study the influence of the structure of this taxonomy network on countries' development; in particular, guided by an example taken from the industrialization of South Korea, we link the structure of the taxonomy network to the empirical temporal connections between product activations, finding that the most relevant edges for countries' development are the ones suggested by our network. These results suggest paths in the product space which are easier to achieve, and so can drive countries' policies in the industrialization process.Comment: 16 pages, 8 figure

The Genoese Ships in the 12th and 13th Centuries.

The history of the great Genoese power has generally well known historical reputation, which continues over the decades, with its roots sunk in the Middle Ages and lasting until the Renaissance, period of greater magnificence, in which it was known as the Superba. From a historical point of view related to shipbuilding, it is therefore interesting to find out which boats had to compose and thus give life to this great traffic network, above all commercial and diplomatic, which made Genoa great; in particular we will concentrate in the 12th and 13th centuries, when the control of the city came to include the coasts from Ventimiglia to Portovenere and it was in the full development and economic expansion of this enormous maritime power. Entering between different issues such as the analysis of the most used boats, which were in particular the navis, the commercial boat for excellence, the galley, with the thinnest and fastest shape compared to the previous one and the bucius, a type similar to the navis for the shape of hull even if of reduced dimensions, we want to expose, albeit in an area limited to an academic article, the development in these centuries of these boats. We also want to take into consideration the economic value that these boats had been taking into account different factors that affected it, such as the age of the ship and its state of preservation; we will also give a look to the men who were part of this fermented world, as could be the shipwright during the construction, the owner or co-owners of the ships, and also the crewmen who made the boat alive each with different tasks, how could they be rowers, armed sailors and officers, guiding her along the different routes, during the trips across the Mediterranean. All this without neglecting some aspects of life that were part of the activities carried out all around the boats, dwelling for example on the relations between the shipyard and the client, or the loca, an investment vehicle widely used by the traders of the time. It will also be shown how the trade routes were modified, noting an expansion of the range of action in conjunction with the passage of time, an effect explained by the probable increase in length and size that the boats themselves underwent changing over decades. This operation is possible thanks to the analysis of the notary documents preserved in the State Archives of Genoa and of the contemporary genre literature such as the Annals of Caffaro di Rustico Da Caschifellone (1080 or 1081 - circa 1164), crusader as well as analyst and diplomat who gave us a vast compendium of information recording the chronicles of the city of Genoa relating to the Middle Ages

L’Oréal Paris Italia changes his communication strategy

“L’Oréal Italia Changes his communication strategy ” is a Marketing case study on a business dilemma faced by the cosmetic multinational company L’Oréal Paris Italia in 2013. It analyses the difficulties incurred in formulating a new communication strategy for an anti-wrinkle cream. The 2nd of August 2013, the Italian Antitrust Authority open a commission that inspected L'Oréal Italy for misleading advertising. The product under consideration was the new Revitalif Laser x3, a leading product in the world for L’Oréal. The advertising of this product was conveyed through the press, television, the site, radio and point of sale. In these messages a comparison was made between the results obtained with these cosmetics and those related to an aesthetic Laser treatment. The Antirust believes that the effectiveness of a wrinkle cream can never be compared to that of a laser treatment, a facelift, or even a cosmetic surgery. The Management of L'Oréal had to completely reinvent the communication strategy of the product. The main problem was that the comparison with a laser treatment was at the heart of his identity. How to communicate such a different message to the customer, without generate misleading and without falling again in the claws of the antitrust and incurring in a penalty of hundreds of thousands of euro? In this case, we will have the unique opportunity to see how a multinational company like L’Oréal not only reinvented a product, but became the number one between the anti-ageing in Italy

Sailing Masterpieces. Ship Design and Aesthetics in the Naval Iconography of the 17th Century

The study concerns the decoration of warships of the 17th century through the naval iconography, with particular reference to England, France and the Dutch Republic. The first part deals with the relationship between shipbuilding and aesthetics, particularly alive at the time, considering its significance from a political point of view and the impact that this had on the life of warships. The second part is the result of a research period at the Vasa Museum in Stockholm and presents the warship Vasa as a case study. The technical analysis of the sculptures starts from a global point of view (relationship between hull and decoration) up to the study of the creation of individual sculptures, allowing a deeper understanding of the decoration visible in contemporary iconography

SAT-Based Decision Procedures for Automated Reasoning: a Unifying Perspective

Propositional reasoning (SAT) is an essential part of many reasoning tasks. Many problems in computer science can be compiled to SAT and then effectively decided using state-of-the-art solvers. Alternatively, if reduction to SAT is not feasible, the ideas and technology of state-of-the-art SAT solvers can be useful in deciding the propositional component of the reasoning task being considered. This last approach has been used in different contexts by different authors, many times by authors of this paper. Because of the essential role played by the SAT solver, these decision procedures have been called "SAT-based". SAT-based decision procedures have been proposed for various logics, but also in other areas such as planning. In this paper we present a unifying perspective on the various SAT-based approaches to these different reasoning tasks