61 research outputs found

    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

    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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    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

    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

    Network of networks: A bibliometric analysis

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    This study explores the evolving structure of the rising field of “network of networks” (NoN). Reviewing publications dating back to 1931, we describe the evolution of major NoN research themes in different scientific disciplines and the gradual emergence of an integrated field. We analyse the co-occurrence networks of keywords used in all 7818 scientific publications in Scopus database that mention NoN and other related terms (i.e., “interconnected networks”, “multilayer networks”, “multiplex networks”, “interdependent networks”, “multinetworks”, “multilevel networks”, and “multidimensional networks”). The results show that the NoN began to form as a field mainly in the 1990s around research on neural networks. Diverse aspects of NoN research, indicated by dominant keywords such as “interconnection”, “multilayer”, and “interdependence”, gradually spread to computer and physical sciences. As of 2018, network interdependence – with its application in network resilience and prevention of cascading failure – seems to be one of the key topics attracting broad academic attention. Another noteworthy observation is the emergence of a distinct cluster of terms relevant to nanoscience and nanotechnology. It is envisaged from the analysis that NoN concepts will develop stronger ties with nanoscience with increasing understanding and data acquisition from the molecular, atomic, and subatomic levels
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