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Abstract: Following the aftermath of the 11 September 2001 events, the risks associated with engaging in international dealings have increased substantially, and become more difficult to analyse and predict for decision makers in the economic, financial and political sectors. The importance of country risk analysis is underscored by the existence of several prominent country risk rating agencies, which combine a wide range of qualitative and quantitative information regarding alternative measures of economic, financial and political risk into associated composite risk ratings. However, the accuracy of any rating agency with regard to any or all of these measures is open to question. For this reason, the paper provides a qualitative comparison of country risk rating systems used by seven leading rating agencies. The paper also provides a novel analysis of four risk ratings using univariate and multivariate volatility models for nine East European countries. These ratings are compiled by the International Country Risk Guide, which is the only risk rating agency to provide consistent monthly data for a large number of countries since 1984. The empirical results enable a comparative assessment of the conditional means and volatilities associated with county risk returns, defined as the rate of change in country risk ratings, across the nine East European countries. Moreover, the estimated constant conditional correlation coefficients provide useful information as to whether the countries are similar in terms of shocks to the four risk returns. [Copyright &y& Elsevier]

One of the main goals stated in the proposals for the Common Fisheries Policy (CFP) reform was achieving maximum sustainable yield (MSY) for all European fisheries. In this paper, we propose a fishing rights allocation mechanism or management system, which specifies catch limits for individual fishing fleets to implement MSY harvesting conditions in an age-structured bioeconomic model. An age-structured model in a single species fishery with two fleets having perfect or imperfect fishing selectivity is studied. If fishing technology or gear selectivity depends on the relative age composition of the mature fish stock, fixed harvest proportions, derived from catchability and bycatch coefficients, is not valid anymore. As a result, not only the age-structure and fishing technology but also the estimated level of MSY is steering the allocation of quota shares. The results also show that allocation of quota shares based on historical catches or auctioning may not provide viable solutions to achieve MSY. [ABSTRACT FROM AUTHOR]

Abstract: The mathematical models proposed and studied in the present paper provide a unified framework to understand complex dynamical patterns in vole populations in Europe and North America. We have extended the well-known model provided by Hanski and Turchin by incorporating the diffusion term and spatial heterogeneity and performed several mathematical and numerical analyses to explore the dynamics in space and time of the model. These models successfully predicted the observed rodent dynamics in these regions. An attempt has been made to bridge the gap between the field and theoretical studies carried out by Turchin and Hanski (1997) and Turchin and Ellner (2000) . Simulation experiments, mainly two-dimensional parameter scans, show the importance of spatial heterogeneity in order to understand the poorly understood fluctuations in population densities of voles in Fennoscandia and Northern America. This study shed new light upon the dynamics of voles in these regions. The nonlinear analysis of vole data suggests that the dynamical shift is from stability to chaos. Diffusion driven model systems predict a new type of dynamics not yet observed in the field studies of vole populations carried out so far. This has been termed as chaotic in time and regular in space (CTRS). We observed CTRS dynamics in several simulation experiments. This directs us to expect that dynamics of this animal would be de-correlated in time and simultaneously mass extinctions might be possible at many spatial locations. [Copyright &y& Elsevier]

Abstract: This paper describes the valuation scheme of European, barrier, and Asian options of single asset by using radial basis function approximation. The option prices are governed with Black–Scholes equation. The equation is discretized with Crank–Nicolson scheme and then, the option price is approximated with the radial basis functions with unknown parameters. In the European and the barrier options, the prices are governed with Black–Scholes equation. The governing option of the Asian option, however, is different from them of the others. In that case, one has to adopt the other radial basis functions than that for the original Black–Scholes equation. Finally, numerical results are compared with theoretical and finite difference solutions in order to confirm the validity of the present formulation. [Copyright &y& Elsevier]

• Complex networks analysis is an appropriate tool for studying transport networks. • Railway in europe is strategic for passenger mobility and has not been analysed so far. • A description of the european network is performed and compared with the chinese. • Passenger transfers allows connecting more stations when timetables are synchronised. • Analysis of the connectivity of european cities is carried out considering transfers. Railway transportation is one of the most popular and greenest transportation modes for passengers. Its importance has increased in some regions owing to the deployment of high-speed infrastructures. In Europe, it is a competitive transportation mode for short and medium distance journeys, rivalling airway mode. For topological analysis of transportation networks, Complex Networks Analysis (CNA) appears as a powerful methodology that although used in various circumstances to describe national railway networks, it has not been used thus far at a continental level. In this paper, two topological characterisations of the European International Railway Network are performed using CNA. The first analyses the direct connection among cities in the international railway service using the most commonly used metrics. The results are compared with those of the Chinese Railway Network, of similar size, observing their differences regarding assortativity. The second analysis incorporates passenger transfers between services, discussing how connectivity is improved when timetables are synchronised, remarking the importance of such coordination. Centrality metrics are defined for the assessment of the connectivity of the network. For the sake of realism, thresholds for the maximum reasonable distance to be travelled by train are introduced in the definition of the centrality metrics. [ABSTRACT FROM AUTHOR]