2,350 research outputs found

    Vertical Restraints under Asymmetric Information: On the Role of Participation Constraints

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    We study a manufacturer-retailer relationship where, besides the adverse selection and moral hazard components, it is explicitly considered a type-dependent participation constraint capturing the shadow cost of exclusive dealings. The welfare effects of contracts based on both retail price and sales are compared to those of contracts contingent solely upon sales. When the type-dependent outside option severely aspects the agency problem and contracts are set non-cooperatively, retail price restrictions may be detrimental to consumers. At the same time, if contracts are set cooperatively, we show that whenever sales-based contracts are observed they are detrimental to consumers.asymmetric information, countervailing incentive, double marginalization, resale price maintenance, vertical restraint, welfare

    numerical study of entropy generation within thermoacoustic heat exchangers with plane fins

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    In this paper a simplified two-dimensional computational model for studying the entropy generation characteristics of thermoacoustic heat exchangers with plane fins is presented. The model integrates the equations of the standard linear thermoacoustic theory into an energy balance-based numerical calculus scheme. Relevant computation results are the spatial distribution of the time-averaged temperature, heat fluxes and entropy generation rates within a channel of a parallel-plate stack and adjoining heat exchangers. For a thermoacoustic device working in the refrigeration mode, this study evidences as a target refrigeration output level can be achieved selecting simultaneously the heat exchangers fin length and fin interspacing for minimum entropy generation and that the resulting configuration is a point of maximum coefficient of performance. The proposed methodology, when extended to other configurations, could be used as a viable design tool for heat exchangers in thermoacoustic applications

    Accomplice-Witnesses, Organized Crime and Corruption: Theory and Evidence from Italy

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    Since 1991 the Italian Legislator grants amnesties, protection and even economic bene.ts to former mobsters cooperating with the justice. These incentives were intro- duced to break down omertà. What is the economic logic behind this policy? Did the program succeed? To address these issues we develop a model accounting for the main trade-o¤s involved in the introduction of accomplice-witnesses regulations. We argue that rewarding informants is sometimes necessary to .ght organized crime and show how the optimal amnesty varies with the e¤ectiveness of the protection program, the reliability of the informants.testimonies, the strength of external complicities, and the internal cohesion between criminal partners. The optimal policy sti.es crime, spurs prosecution and induce a negative relationship between the number of talkers and the conviction rate. The available evidence supports the model.s predictions.Accomplice-witnesses, Criminal Organizations, Leniency, Whistle-Blower

    Multi-Sorted Inverse Frequent Itemsets Mining: On-Going Research

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    Inverse frequent itemset mining (IFM) consists of generating artificial transactional databases reflecting patterns of real ones, in particular, satisfying given frequency constraints on the itemsets. An extension of IFM called many-sorted IFM, is introduced where the schemes for the datasets to be generated are those typical of Big Tables, as required in emerging big data applications, e.g., social network analytics

    Accomplice-Witness and Organized Crime: Theory and Evidence from Italy

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    We develop an agency model of organized crime accounting for the main trade-offs involved by the\ud introduction of an accomplice-witness program. We characterize the optimal policy and identify its main\ud determinants in a framework where public officials can be dishonest. Our predictions are tested by using\ud data for Italy before and after the introduction of the 1991 accomplice-witness program. As predicted by\ud the model and the earlier antitrust literature, the program appears to have strengthened deterrence and\ud enhanced prosecution. Moreover, consistently with a novel prediction of our theory, the evidence suggests\ud that the program efficacy is affected by the judicial system efficiency

    A fuzzy logic controller to increase fault ride-through capability of variable speed wind turbines

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    A fuzzy controller for improving Fault Ride-Through (FRT) capability of Variable Speed Wind Turbines (WTs) equipped with Doubly Fed Induction Generator (DFIG) is presented. The controller is designed in order to compensate the voltage at the Point of Common Coupling (PCC) by regulating the reactive and active power generated by WTs. The performances of the controller are evaluated in some case studies considering a different number of wind farms in different locations. Simulations, carried out on a real 37-bus Italian weak distribution system, confirmed that the proposed controller can enhance the FRT capability in many cases

    Decomposition of bio‑degradable plastic polymer in a real on‑farm composting process

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    Background: The current wide diffusion of bio-degradable plastic made up by starch-based polymeric composite has focused the attention on the allocation of bio-polymers for the direct recycling in composting processes. Actually, the acknowledged current methods to estimate the bio-degradability are mainly based on laboratory tests and measurements under controlled conditions, while scarce information are available on the effective transformation of bio-film derivatives in real composting facilities. The aim of this paper was to determine at molecular level the decomposition of specific starch-based thermoplastic mulching film for horticultural crops, in a real on-farm composting system for the attainment of mature compost for agricultural application. Results: The initial and final molecular composition of both bulk biomasses and bio-plastic composite were evaluated through 13C solid-state CPMAS-NMR spectroscopy and off-line thermochemolysis—gas chromatography–mass spectrometry. The effective decomposition of the bio-polymer was shown by mono-dimensional and pseudo-2D NMR experiments that revealed the alteration of the intermolecular linkages among the monomeric constituents, while the thermochemolysis confirmed the complete decomposition of starch components. Concomitantly, the molecular characterization of bulk compost indicated the typical selective preservation of hydrophobic components currently found in aerobic composting processes, with a significant increase (+50 %) for the yields of aromatic lignin derivatives and recalcitrant aliphatic compounds. Conclusion: In addition to the classical testing methodologies, the detailed analytical investigation represents a powerful methodology to elucidate the molecular composition and modification of plastic bio-polymers thereby providing a valuable contribution to further promote the composting process as viable way to recycle the biodegradable polymeric materials
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