General equilibrium in asset markets with or without short-selling

Equilibrium Theory;Assets

A communication platform demonstrator for new generation railway traffic management systems: Testing and validation

Current rail traffic management and control systems cannot be easily upgraded to the new needs and challenges of modern railway systems because they do not offer interoperable data structures and standardized communication interfaces. To meet this need, the Horizon 2020 Shift2Rail OPTIMA project has developed a communication platform for testing and validating the new generation of traffic management systems (TMS), whose main innovative features are the interoperability of the data structures used, standardization of communications, continuous access to real-time and persistent data from heterogeneous data sources, modularity of components and scalability of the platform. This paper presents the main components, their functions and characteristics, then describes the testing and validation of the platform, even when federated with other innovative TMS modules developed in separate projects. The successful validation of the system has confirmed the achievement of the objectives set and allowed a new set of objectives to be defined for the reference platform for the railway TMS/Traffic Control systems

A communication platform demonstrator for new generation railway traffic management systems: Testing and validation

\ua9 2023 The Author(s). Current rail traffic management and control systems cannot be easily upgraded to the new needs and challenges of modern railway systems because they do not offer interoperable data structures and standardized communication interfaces. To meet this need, the Horizon 2020 Shift2Rail OPTIMA project has developed a communication platform for testing and validating the new generation of traffic management systems (TMS), whose main innovative features are the interoperability of the data structures used, standardization of communications, continuous access to real-time and persistent data from heterogeneous data sources, modularity of components and scalability of the platform. This paper presents the main components, their functions and characteristics, then describes the testing and validation of the platform, even when federated with other innovative TMS modules developed in separate projects. The successful validation of the system has confirmed the achievement of the objectives set and allowed a new set of objectives to be defined for the reference platform for the railway TMS/Traffic Control systems

Structure of NaFeSiO4, NaFeSi2O6, and NaFeSi3O8 glasses and glass-ceramics

The crystallization of iron-containing sodium silicate phases holds particular importance, both in the management high-level nuclear wastes and in geosciences. Here, we study three asquenched glasses and their heat-treated chemical analogues, NaFeSiO4, NaFeSi2O6, and NaFeSi3O8 (with nominal stoichiometries from feldspathoid, pyroxene, and feldspar mineral groups – i.e., Si/Fe = 1, 2, and 3 respectively) – using a variety of techniques. Phase analyses revealed that as-quenched NaFeSiO4 cannot accommodate all Fe in the glass phase (some Fe crystallizes as Fe3O4), whereas as-quenched NaFeSi2O6 and NaFeSi3O8 form amorphous glasses upon quenching. NaFeSi2O6 glass is the only composition that crystallizes into its respective isochemical crystalline polymorph, i.e. aegirine, upon isothermal heat-treatment. As revealed by Mössbauer spectroscopy, iron is predominantly present as 4-coordinated Fe3+ in all glasses, though it is present as 6-coordinated Fe3+ in the aegirine crystals (NaFeSi2O6), as expected from crystallography. Thus, Fe can form the crystalline phases in which it is octahedrally coordinated, even though it is mostly tetrahedrally coordinated in the parent glasses. Thermal behavior, magnetic properties, iron redox state (including Fe K-edge X-ray absorption), and vibrational properties (Raman spectra) of the above compositions are discussed

On the Different Notions of Arbitrage and Existence of Equilibrium.

In this paper we first prove an equilibrium existe theorem for finite dimensional economies with unbounded below consumption sets. We only assume that the individually rational utility set is compact and use the demand approach instead of the standard Negishi's approach. We next compare the different concepts of no-arbitrage that have been used in the literature and give conditions for equivalence between absence of arbitrage and existence of equilibrium. Lastly, we introduce the concept of strong unbounded arbitrage and show that the absence of strong unbounded arbitrage implies the compactness of the individually rational utility set.PRICES ; ARBRITATION ; CONSUMPTION