4,014 research outputs found

    Quotient spaces of boundedly rational types

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    By identifying types whose low-order beliefs – up to level li – about the state of nature coincide, we obtain quotient type spaces that are typically smaller than the original ones, preserve basic topological properties, and allow standard equilibrium analysis even under bounded reasoning. Our Bayesian Nash (li; l-i)-equilibria capture players’ inability to distinguish types belonging to the same equivalence class. The case with uncertainty about the vector of levels (li; l-i) is also analyzed. Two examples illustrate the constructions.Incomplete-information games, high-order reasoning, type space, quotient space, hierarchies of beliefs, bounded rationality

    Generalized Burniat type surfaces and Bagnera-de Franchis varieties

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    In this article we construct three new families of surfaces of general type with p_g = q = 0,K^2 = 6, and seven new families of surfaces of general type with p_g = q = 1, K^2 = 6, realizing 10 new fundamental groups. We also show that these families correspond to pairwise distinct irreducible connected components of the Gieseker moduli space of surfaces of general type. We achieve this using two different main ingredients. First we introduce a new class of surfaces, called generalized Burniat type surfaces, and we completely classify them (and the connected com- ponents of the moduli space containing them). Second, we introduce the notion of Bagnera-de Franchis varieties: these are the free quotients of an Abelian variety by a cyclic group (not consisting only of translations). For these we develop some basic results.Comment: 45 pages, 6 tables, two MAGMA scripts; v2: minor changes. To appear in Kodaira Centennial issue of Journal of Mathematical Sciences, the University of Toky

    Assessing systemic risk due to fire sales spillover through maximum entropy network reconstruction

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    Assessing systemic risk in financial markets is of great importance but it often requires data that are unavailable or available at a very low frequency. For this reason, systemic risk assessment with partial information is potentially very useful for regulators and other stakeholders. In this paper we consider systemic risk due to fire sales spillover and portfolio rebalancing by using the risk metrics defined by Greenwood et al. (2015). By using the Maximum Entropy principle we propose a method to assess aggregated and single bank's systemicness and vulnerability and to statistically test for a change in these variables when only the information on the size of each bank and the capitalization of the investment assets are available. We prove the effectiveness of our method on 2001-2013 quarterly data of US banks for which portfolio composition is available.Comment: 36 pages, 6 figures, Accepted on Journal of Economic Dynamics and Contro

    PowerDrive: Accurate De-Obfuscation and Analysis of PowerShell Malware

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    PowerShell is nowadays a widely-used technology to administrate and manage Windows-based operating systems. However, it is also extensively used by malware vectors to execute payloads or drop additional malicious contents. Similarly to other scripting languages used by malware, PowerShell attacks are challenging to analyze due to the extensive use of multiple obfuscation layers, which make the real malicious code hard to be unveiled. To the best of our knowledge, a comprehensive solution for properly de-obfuscating such attacks is currently missing. In this paper, we present PowerDrive, an open-source, static and dynamic multi-stage de-obfuscator for PowerShell attacks. PowerDrive instruments the PowerShell code to progressively de-obfuscate it by showing the analyst the employed obfuscation steps. We used PowerDrive to successfully analyze thousands of PowerShell attacks extracted from various malware vectors and executables. The attained results show interesting patterns used by attackers to devise their malicious scripts. Moreover, we provide a taxonomy of behavioral models adopted by the analyzed codes and a comprehensive list of the malicious domains contacted during the analysis

    Selecting eco-friendly thermal systems for the "Vittoriale Degli Italiani" historic museum building

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    Thermal systems installed in museums should guarantee the maintenance of the optimal hygrothermal parameters ranges for the conservation of their collection materials. Considering the preservation of historic buildings, according to their historical and landscaping constraints, not all the thermal system typologies could be installed in these buildings' typologies. Therefore, the main aim of this paper is to present some indications for the choice of the best thermal system solutions for a considered historic museum building, called Vittoriale degli Italiani, in the north of Italy, taking into account their installation feasibility and their related environmental impacts. The methodology includes a monitoring of the current hygrothermal parameters as well as the assessment of design heat and cooling loads related to the maintenance of the optimal hygrothermal parameters ranges for the conservation of collection materials. In addition, a Life Cycle Assessment (LCA) of each selected system typology is considered for highlighting the most eco-friendly solution among the suitable ones. The obtained results highlights the feasible thermal system solutions able to maintain the hygrothermal parameters between the optimal ranges with a lower environmental impact in the Vittoriale degli Italiani historic museum building

    Technologies and strategies to design sustainable tourist accommodations in areas of high environmental value not connected to the electricity grid

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    As envisaged in the Agenda for a sustainable and competitive European tourism, the adoption of an holistic and integrated approach and the use of the best available knowledge and technologies are key aspects to ensure a sustainable tourism. In particular, policies and actions should be planned considering the latest and best available knowledge, analyzing at the same time all the related impacts on the area of intervention. In this context, the purpose of this paper is to describe an approach for designing sustainable tourist accommodations that allow the fruition of areas characterized by high environmental values minimizing the related impacts on the surrounding environment and sensitizing users towards preservation and conservation of natural resources. In the proposed approach three aspects of tourist accommodation have been considered: the system component, the building envelope and the integration between them. As a result, the architectural structures designed, including their materials, shape, energy efficiency, modularity and removability, are in line with the standards of bio-architecture. The materials used, complying with the technical requirements and the technological needs of the tourist accommodations, are mostly recycled or reusable, coming from the surrounding area or of easy integration in the landscape. The components , that constitute the accommodations, are easy to assemble and disassemble for reuse them in another area, without changing the environmental conditions in the site. Some elements are precast and completed on site with local materials, moreover the modularity allows a high adaptability to different environmental and morphological conditions. To apply these architectural structures even in places without services and distribution networks of energy and water, special attention has been given to innovative and sustainable energy solutions: Liquefied petroleum gas (LPG) has been used as the only energy vector, combined with a cogeneration plant to provide heat and electric energy as well as with particular building envelopes that allow the transfer of LPG into the walls for provide energy to innovative gas appliances. Lastly, in order to assess the environmental impact of the proposed approach, it has been analyzed the environmental insertion of these structures for tourist accommodation in the Circeo National Park, in Italy

    A sustainable requalification of Bracciano lake waterfront in Trevignano Romano

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    This paper describes the first interventions carried out in accordance with the results of the three years bilateral research SoURCE (Sustainable Urban Cell) performed by CITERA (Inter department Centre for Territory, Building, Conservation and Environment) of the Sapienza University of Rome and the Department of Urban Planning and Environment of the Royal Institute of Technology of Stockholm (KTH) regarding urban redevelopment and distributed micro-generation of buildings. The location is the municipality of Trevignano Romano in the area (urban cell) of the lake waterfront aimed at the integration of all facilities that will increase the tourist accommodation of the area. The concept of the project is to utilize empty spaces, in all lake waterfronts, for the construction of public toilets and showers, introduction of electric boat and bike rental for sightseeing with charging stations and construction of an energy efficient wooden prefabricated building to be used as a general shop for tourists (closest analogue service is about 3 km). The research is included in the executive programme for the scientific and technical cooperation between the Kingdom of Sweden and the Republic of Italy, in the area defined ‘Energy and Environment: Sustainable Cities’

    The Costs of Disposal and Recycling. An Application to Italian Municipal Solid Waste Services

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    The paper investigates the costs of waste disposal and recycling services by using a well-behaved Composite cost function model. Our estimates on a unique sample of more than 500 Italian municipalities highlight that the refuse collection technology exhibits constant returns to scale as well as scope economies between disposal and recycling. As far as the size of the municipality increases, scope economies rise up to 14%, but they are accompanied with overall diseconomies of scale. Our findings suggest that, on the one hand, joint management of disposal and recycling should be encouraged, and, on the other hand, that strategies aimed at increasing the share of waste sent for recycling would not imply a considerable increase in total costs.Solid waste, recycling, cost functions

    The Costs of Disposal and Recycling. An Application to Italian Municipal Solid Waste Services

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    The paper investigates the costs of waste disposal and recycling services by using a well-behaved Composite cost function model. Our estimates on a unique sample of more than 500 Italian municipalities highlight that the refuse collection technology exhibits constant returns to scale as well as scope economies between disposal and recycling. As far as the size of the municipality increases, scope economies rise up to 14%, but they are accompanied with overall diseconomies of scale. Our findings suggest that, on the one hand, joint management of disposal and recycling should be encouraged, and, on the other hand, that strategies aimed at increasing the share of waste sent for recycling would not imply a considerable increase in total costs.solid waste, recycling, cost functions

    The determinants of board compensation in SOEs. An application to Italian local public utilities

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    This paper investigates the determinants of board compensation for a sample of Italian State Owned Enterprises (SOEs). To that purpose, we use a newly collected panel data of 106 local public utilities observed form 1994 through 2004, which includes detailed information on the boards of directors. During this period, the deregulation process inspired institutional interventions that forced utilities, traditionally owned by local municipalities, to change their juridical form and ownership structure, thereby facilitating the entrance of private investors. The corporate governance literature shows that such changes may exacerbate the agency conflicts between shareholders, top executives and the board. However, board compensation could reduce the agency costs by aligning the incentives of managers with the interests of shareholders. This paper addresses this issue by investigating the impact that board composition, firm characteristics and performance have on board compensation. We find that the average board pay is negatively related to board size and positively related to firm dimension. The public or private nature of the major shareholder does not influence board compensation but the juridical form does. Finally, while the proportion of politically connected directors is found to negatively influence the level of per capita compensation, the impact of firm performance is uncertain.board compensation, board composition, politicians, local public utilities
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