Spectral properties of the hierarchical product of graphs

The hierarchical product of two graphs represents a natural way to build a larger graph out of two smaller graphs with less regular and therefore more heterogeneous structure than the Cartesian product. Here we study the eigenvalue spectrum of the adjacency matrix of the hierarchical product of two graphs. Introducing a coupling parameter describing the relative contribution of each of the two smaller graphs, we perform an asymptotic analysis for the full spectrum of eigenvalues of the adjacency matrix of the hierarchical product. Specifically, we derive the exact limit points for each eigenvalue in the limits of small and large coupling, as well as the leading-order relaxation to these values in terms of the eigenvalues and eigenvectors of the two smaller graphs. Given its central roll in the structural and dynamical properties of networks, we study in detail the Perron-Frobenius, or largest, eigenvalue. Finally, as an example application we use our theory to predict the epidemic threshold of the Susceptible-Infected-Susceptible model on a hierarchical product of two graphs

Retail Internationalization and Its Consequences on the Food Chain

In order to meet with the obstacles of market saturation and the resulting cut-throat competition in the home countries of most of the top food retailers, they use the chance to participate in the increasing standard of living in Asia, South America and Central- and Eastern Europe. Thus, retail internationalization can be regarded as a growth strategy for top food retailers. However, opposite to manufacturers internationalization is for retailers still a new strategy so that globalization continues to accelerate. AT Kearney (2006) shows that since 2001 more than 50 different retailers have entered 90 new markets. In this context our the aim of our paper is threefold. First, using different theories of internationalization we want to work out the courses why the retailers internationalize. Furthermore, by analyzing secondary data we will show the actual degree of internationalization. Second, using theories of the new institutional economics as well as strategic management we will elaborate on its consequences for the participants of the agri-food business. Building on the more general parts of our aim the third part contributes to the developments in Central and Eastern Europe. This includes a detailed analysis of the current situation and an outlook to future developments.CEEC, consequences, retail internationalization, Agribusiness, International Relations/Trade,

Bio-fuel Chains – An Overview on the Structure and the Value Chain Organization

Structural change in the agricultural sector as well as in the whole agricultural value chain is an ongoing dynamic process and creates a number of diverse phenomena. The EU Strategy for Biofuels (2006) and the Biomass action plan (2005) set a clear signal that the EU wishes to establish and to support the bio energy-industry. The perceivable aim of the Common Agricultural Policy (CAP) consists in reducing food production and in enlarging the non-food production. Another driver for the attractiveness of bio-energy and bio-fuel production is the recent development of prices of crude oil and natural gas. Furthermore bio-energy is seen as one of the key options to reduce greenhouse gas emissions and substitute fossil fuels.Agribusiness, Industrial Organization,

Simulated nitrogen leaching, nitrogen mass field balances and their correlation on four farms in south-western Finland during the period 2000-2005

Nitrogen (N) gross balance is one of the indicators designed for following developments in agriculture in the European Union. A nutrient surplus occurs when the quantity of a nutrient applied in fertilizers is greater than that removed during harvest. In this study the usefulness of N balance in studying the fate of N and controlling N leaching from agricultural fields in south-western Finland was evaluated. To estimate N leaching in 2000–2005 the mathematical, process-based model COUP was applied to twelve fields representing four agricultural production sectors. The fields represented conventional cereal production, organic cereal production and both conventional cattle and pig husbandry. Simulated N leaching was lowest from cereal production fields with a low N balance. Higher N leaching from pig and cattle production farms might be reduced by decreasing the N balance but also by applying manure in spring instead of autumn. Both N balance and simulated N leaching from organic farm were relatively high compared to low N application rate to the fields. N balance appears to be a rather useful indicator of N leaching over longer periods of time. In the short term, N leaching depends mainly on precipitation and on cultivation practices, like timing and amount of fertilizer application. Statistical evaluation indicated significant positive correlation between calculated N balance and simulated N leaching, especially when supported by constant values of precipitation and N mineralization rate. Decrease of N balance by 1 kg ha–1yr–1 decreased N leaching by 0.3 kg ha–1yr–1. High positive N balances are conducive to abundant accumulation of residual N in soil and consequently to a high risk of N leaching during rainy seasons

Payment and Settlement Systems in Finland 1995

This paper is an overview of domestic payment and settlement systems in Finland. It contains an up-to-date description of institutional aspects of payment systems, payment media used by non-banks, interbank exchange and settlement circuits and securities settlement systems. At the end of the paper, annual statistics are presented on payment and settlement systems and on payment media for the years 1989–1994.clearing; settlement; payment media; Finland