66 research outputs found

    Environmental Investments in Mixed vs Private Oligopoly: What are the Implications of Privatization?

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    We compare economic and environmental outcomes under mixed and private oligopolies,in order to examine the effects of privatization when firms invest in abatement and emissions are taxed. We show that the number of competing firms in the market is an important factor in the determination of these effects. While privatization often involves a welfare trade-of, in the sense that higher (lower) output production implies higher (lower) pollution, there are also circumstances where it leads to both lower output and higher emissions simultaneously. Our results also indicate that privatization tends be associated with reductions in social welfare

    Αξιολόγηση του συστήματος αναγνώρισης αγροτεμαχίων σε σχέση με το Ε.Κ.

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    103 σ.Αξιολόγηση του Συστήματος Αναγνώρισης Αγροτεμαχίων σε σχέση με το Ε.Κ.Αντώνιος Δ. Βαρβαρίγο

    The Minimum Shared Edges Problem on Grid-like Graphs

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    We study the NP-hard Minimum Shared Edges (MSE) problem on graphs: decide whether it is possible to route pp paths from a start vertex to a target vertex in a given graph while using at most kk edges more than once. We show that MSE can be decided on bounded (i.e. finite) grids in linear time when both dimensions are either small or large compared to the number pp of paths. On the contrary, we show that MSE remains NP-hard on subgraphs of bounded grids. Finally, we study MSE from a parametrised complexity point of view. It is known that MSE is fixed-parameter tractable with respect to the number pp of paths. We show that, under standard complexity-theoretical assumptions, the problem parametrised by the combined parameter kk, pp, maximum degree, diameter, and treewidth does not admit a polynomial-size problem kernel, even when restricted to planar graphs

    A Survey of Quality of Service Differentiation Mechanisms for Optical Burst Switching Networks

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    Cataloged from PDF version of article.This paper presents an overview of Quality of Service (QoS) differentiation mechanisms proposed for Optical Burst Switching (OBS) networks. OBS has been proposed to couple the benefits of both circuit and packet switching for the ‘‘on demand’’ use of capacity in the future optical Internet. In such a case, QoS support imposes some important challenges before this technology is deployed. This paper takes a broader view on QoS, including QoS differentiation not only at the burst but also at the transport levels for OBS networks. A classification of existing QoS differentiation mechanisms for OBS is given and their efficiency and complexity are comparatively discussed. We provide numerical examples on how QoS differentiation with respect to burst loss rate and transport layer throughput can be achieved in OBS networks. © 2009 Elsevier B.V. All rights reserved

    A survey of quality of service differentiation mechanisms for optical burst switching networks

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    This paper presents an overview of Quality of Service (QoS) differentiation mechanisms proposed for Optical Burst Switching (OBS) networks. OBS has been proposed to couple the benefits of both circuit and packet switching for the "on demand" use of capacity in the future optical Internet. In such a case, QoS support imposes some important challenges before this technology is deployed. This paper takes a broader view on QoS, including QoS differentiation not only at the burst but also at the transport levels for OBS networks. A classification of existing QoS differentiation mechanisms for OBS is given and their efficiency and complexity are comparatively discussed. We provide numerical examples on how QoS differentiation with respect to burst loss rate and transport layer throughput can be achieved in OBS networks. © 2009 Elsevier B.V. All rights reserved

    Bottlenecks in diagnostics of Mediterranean fish diseases

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    Three independent Horizon 2020 projects are prioritising a common task of solving diagnostic issues using different approaches and strategies. PerformFISH focuses its research objectives on diagnostic methods, MedAID has prepared a diagnostic manual for the most devastating fish diseases of the Mediterranean and ParaFishControl has prepared a diagnostic manual on parasitic diseases of European aquaculture species. Currently, the projects are investing large collaborative efforts to reinforce their tasks and to deliver mutual and cutting-edge material on the subject. Nevertheless, further efforts for the harmonisation, standardisation and validation of diagnostic methods for infectious diseases in Mediterranean aquaculture are needed, involving as many relevant stakeholders and experts as possible. The main goal of the workshop (WS) “Bottlenecks in diagnostics of Mediterranean fish diseases”, organised during the 19th International EAFP conference on Diseases of Fish and Shellfish, was to present results already obtained from the projects and discuss the bottlenecks in diagnostic procedures of target groups of pathogens. The WS provided an ideal environment and opportunity to exchange and discuss experiences and data with international experts in the diagnostic field attending the conference. Interactive discussions on diagnostics for a specific group of pathogens have resulted in highlighting new initiatives needed in the management of diseases in Mediterranean aquaculture. Furthermore, the WS emphasised a need for the establishment of this strong interactive network which will collaborate to receive, collect, compile and analyse all information gathered from different parts of the region.info:eu-repo/semantics/publishedVersio

    Policy volatility and growth

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    The paper aims to examine how fiscal and monetary volatility might affect the balanced economic growth rate using a standard monetary growth model characterized by nominal wage rigidity and productive public spending. The model shows that any type of shock — monetary or fiscal — can generate either a negative or positive relationship between short-run volatility and long-run growth, critically de- pending on the size of government and the elasticity of output with respect to labor/ capital. In particular, given the labor income share, it shows that excessive government spending may cause the impact of fiscal volatility on long-run growth to turn from positive to negative. In addition, a rise in the volatility of the monetary shock is capable of generating either an increase or decrease in the mean of growth. With the range of the labor share values in reality, the model produces results consistent with the fact that the relationship between volatility and growth is generally found empirically to be more negative in developing than in developed countries. The model can be seen as a further explanation for the ambiguous empirical evidence in the existing literature.info:eu-repo/semantics/publishedVersio
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