EC Reforms of Corporate Governance and Capital Markets Law: Do They Tackle Insiders\u27 Opportunism?

Company and capital markets laws are rapidly evolving everywhere: there are few countries around the world where they have not been the subject of reform or where at least a reform agenda has not been devised. There are various reasons for this, both global and local. Among the global (or common) reasons for reform, two at least deserve to be singled out: large-scale market crises or prominent economic scandals, and financial development

Analysis of geometrical and topological attitude for proteinprotein interaction

Protein-protein interaction takes usually place on an extended area of the external molecules surfaces that are morphologically fitting. Geometric and topological congruence (i.e. concavity and convexity correspondences) is required to support the neighboring interaction of surface patches belonging to the two protein molecules. It is therefore important to adopt representations and data structures that can facilitate the analysis and the implementation of techniques for the evaluation of geometric and topological properties on extended surfaces. These areas of activity are usually roughly “planar” but with local concavity and complexity that must match each other for interacting. To this purpose we are suggesting a solution different from the one of ligand-protein interaction in which are involved a pocket and a small molecule. The solution here suggested is based on the concavity tree representation. Starting from the convex hull of the protein molecule a recursive process leads to a series of concavity and meta-concavity that allows reaching the detail level required. The consequence of the recursive process is obviously a hierarchical data structure (a tree) which at each level supports a complete description of a surface. Each node of the tree contains an array of features that support the geometrical, topological and biochemical properties of the correspondent surface patch

Diamanti, magneti e altre noterelle di mineralogia nella lirica medievale

Il saggio propone una campionatura di immagini mineralogiche nella lirica romanza medievale: si ritorna, in particolare, sull’immagine del diamante. Almeno per taluni casi, pare lecito supporre la mediazione di una fonte letteraria; per talaltri, invece, è possibile leggere una rifunzionalizzazione, più o meno marcata, in seno all’ideologia della fin’amor.The essay proposes a sampling of mineralogical images in medieval Romance lyric: we will focus, in particular, on the image of the diamond. At least in some cases, it seems legitimate to suppose the mediation of a literary source; for some, on the other hand, it is possible to read a refunctionalization within the ideology of fin’amor

Public Information Representation for Adversarial Team Games

The peculiarity of adversarial team games resides in the asymmetric information available to the team members during the play, which makes the equilibrium computation problem hard even with zero-sum payoffs. The algorithms available in the literature work with implicit representations of the strategy space and mainly resort to Linear Programming and column generation techniques to enlarge incrementally the strategy space. Such representations prevent the adoption of standard tools such as abstraction generation, game solving, and subgame solving, which demonstrated to be crucial when solving huge, real-world two-player zero-sum games. Differently from these works, we answer the question of whether there is any suitable game representation enabling the adoption of those tools. In particular, our algorithms convert a sequential team game with adversaries to a classical two-player zero-sum game. In this converted game, the team is transformed into a single coordinator player who only knows information common to the whole team and prescribes to the players an action for any possible private state. Interestingly, we show that our game is more expressive than the original extensive-form game as any state/action abstraction of the extensive-form game can be captured by our representation, while the reverse does not hold. Due to the NP-hard nature of the problem, the resulting Public Team game may be exponentially larger than the original one. To limit this explosion, we provide three algorithms, each returning an information-lossless abstraction that dramatically reduces the size of the tree. These abstractions can be produced without generating the original game tree. Finally, we show the effectiveness of the proposed approach by presenting experimental results on Kuhn and Leduc Poker games, obtained by applying state-of-art algorithms for two-player zero-sum games on the converted gamesComment: 19 pages, 7 figures, Best Paper Award in Cooperative AI Workshop at NeurIPS 202

Improving Energy Conserving Descent for Machine Learning: Theory and Practice

We develop the theory of Energy Conserving Descent (ECD) and introduce ECDSep, a gradient-based optimization algorithm able to tackle convex and non-convex optimization problems. The method is based on the novel ECD framework of optimization as physical evolution of a suitable chaotic energy-conserving dynamical system, enabling analytic control of the distribution of results - dominated at low loss - even for generic high-dimensional problems with no symmetries. Compared to previous realizations of this idea, we exploit the theoretical control to improve both the dynamics and chaos-inducing elements, enhancing performance while simplifying the hyper-parameter tuning of the optimization algorithm targeted to different classes of problems. We empirically compare with popular optimization methods such as SGD, Adam and AdamW on a wide range of machine learning problems, finding competitive or improved performance compared to the best among them on each task. We identify limitations in our analysis pointing to possibilities for additional improvements.Comment: 15 pages + appendices, full code availabl

A marriage between adversarial team games and 2-player games: enabling abstractions, no-regret learning, and subgame solving

Ex ante correlation is becoming the mainstream approach for sequential adversarial team games,where a team of players faces another team in a zero-sum game. It is known that team members’asymmetric information makes both equilibrium computation APX-hard and team’s strategies not directly representable on the game tree. This latter issue prevents the adoption of successful tools for huge 2-player zero-sum games such as, e.g., abstractions, no-regret learning, and sub game solving. This work shows that we can re cover from this weakness by bridging the gap be tween sequential adversarial team games and 2-player games. In particular, we propose a new,suitable game representation that we call team public-information, in which a team is repre sented as a single coordinator who only knows information common to the whole team and pre scribes to each member an action for any pos sible private state. The resulting representation is highly explainable, being a 2-player tree in which the team’s strategies are behavioral with a direct interpretation and more expressive than he original extensive form when designing ab stractions. Furthermore, we prove payoff equiva lence of our representation, and we provide tech niques that, starting directly from the extensive form, generate dramatically more compact repre sentations without information loss. Finally, we experimentally evaluate our techniques when ap plied to a standard testbed, comparing their per formance with the current state of the art

Plasmon‐Assisted Energy Transfer in Hybrid Nanosystems

While direct optical excitation of carbon nanotubes activates only the tube species strictly matching the excitation source, excitation energy transfer processes provide a single excitation channel for all the nanotubes species in a sample. The requirement of an overlap between donor emission and acceptor absorption limits the poll of donors able to trasfer their excitation to the tubes, leaving the high‐energy part of the solar spectrum excluded from such processes. Here it is shown that the grafting of small metal nanoparticles to the tubes alters those rules, enabling energy transfer process from molecules for which the standard energy transfer process is strongly suppressed. The onset of an energy transfer band in the UV/blue spectral region is demonstrated for an hybrid gold‐pyrene‐nanotube system, yielding collective emission from all the tubes present in our samples upon excitation of pyrene