The Innovation Threshold

In this paper, we propose an economic model to analyse the sales out of new products. This model accounts for the fact that even among firms for which R&D is a permanent activity, a fraction of firms does not have sales of innovative products during a two-year observation period. We propose a model in which the fixed costs of introduction is a major concern in the decision making process. In a structural model we estimate the fixed costs of the market introduction of new products and explain subsequent sales of innovative products. We examine an indicator of innovative output, i.e. sales of products 'new to the firm'. We estimate fixed costs thresholds using data from the Dutch part of the Community Innovation Survey (CIS) from 1998. R&D intensity, competition and market structure have a positive impact on sales of new products. The most important factors to decrease the fixed costs threshold of introduction are product related R&D investments, R&D subsidies and knowledge spillovers.Innovation;Product R&D;Threshold model

Costs of compliance with EU regulations and competitiveness of the EU dairy sector

The introduction of cross-compliance mechanism in the European Union with its 2003 CAPreform might affect the costs of production and thus competitiveness of the EU. Little evidence is available to asses the costs of compliance with regulations and it implication for trade. In this study a farm level competitiveness analysis of the impacts of the Nitrate Directive and the Identification & registration Directive focuses on the dairy sector in Germany, France, Italy, Netherlands and UK (within EU), and the US and New Zealand (outside EU). The findings from this study are integrated into a trade analysis which assesses the impact of compliance costs on competitiveness of the various trading nations in global trade. Representative farm studies were used as a basis for the cost increase calculations. Best-estimates of compliance are used from the existing literature and expert judgements. The negative impact of these measures (for nitrates, and animal identification and registration) on EU imports and exports are less than 3 percent. If a smaller increase in compliance takes place, these already relatively small trade impacts will be further diminished. When the standards for nitrate pollution taken by the US and New Zealand are taken into account along with full compliance assumption in all countries analysed, this would only slightly improve the EU exports. The trade impacts obtained when no changes are assumed to happen in key competitor countries can thus be argued as providing the upper bound of the likely trade impacts

Expansive homeomorphisms of the plane

This article tackles the problem of the classification of expansive homeomorphisms of the plane. Necessary and sufficient conditions for a homeomorphism to be conjugate to a linear hyperbolic automorphism will be presented. The techniques involve topological and metric aspects of the plane. The use of a Lyapunov metric function which defines the same topology as the one induced by the usual metric but that, in general, is not equivalent to it is an example of such techniques. The discovery of a hypothesis about the behavior of Lyapunov functions at infinity allows us to generalize some results that are valid in the compact context. Additional local properties allow us to obtain another classification theorem.Comment: 29 pages, 22 figure

Crossover of magnetoconductance autocorrelation for a ballistic chaotic quantum dot

The autocorrelation function C_{\varphi,\eps}(\Delta\varphi,\,\Delta \eps)= \langle \delta g(\varphi,\,\eps)\, \delta g(\varphi+\Delta\varphi,\,\eps+\Delta \eps)\rangle ($\varphi$ and \eps are rescaled magnetic flux and energy) for the magnetoconductance of a ballistic chaotic quantum dot is calculated in the framework of the supersymmetric non-linear $\sigma$-model. The Hamiltonian of the quantum dot is modelled by a Gaussian random matrix. The particular form of the symmetry breaking matrix is found to be relevant for the autocorrelation function but not for the average conductance. Our results are valid for the complete crossover from orthogonal to unitary symmetry and their relation with semiclassical theory and an $S$-matrix Brownian motion ensemble is discussed.Comment: 7 pages, no figures, accepted for publication in Europhysics Letter

CROSS-COMPLIANCE Facilitating the CAP reform: Compliance and competitiveness of European agriculture Specific Targeted Research or Innovation Project (STREP) Integrating and Strengthening the European Research Area : Deliverable 13 : Product-based assessments to link compliance to standards at farm level to competitiveness

This report summarizes the main results from the Cross-Compliance project The core aim of this EU funded research project is to analyse the external competitiveness impact arising from an improvement in the level of compliance with mandatory standard

A nearly closed ballistic billiard with random boundary transmission

A variety of mesoscopic systems can be represented as a billiard with a random coupling to the exterior at the boundary. Examples include quantum dots with multiple leads, quantum corrals with different kinds of atoms forming the boundary, and optical cavities with random surface refractive index. The specific example we study is a circular (integrable) billiard with no internal impurities weakly coupled to the exterior by a large number of leads with one channel open in each lead. We construct a supersymmetric nonlinear $\sigma$-model by averaging over the random coupling strengths between bound states and channels. The resulting theory can be used to evaluate the statistical properties of any physically measurable quantity in a billiard. As an illustration, we present results for the local density of states.Comment: 5 pages, 1 figur

Distribution of parametric conductance derivatives of a quantum dot

The conductance G of a quantum dot with single-mode ballistic point contacts depends sensitively on external parameters X, such as gate voltage and magnetic field. We calculate the joint distribution of G and dG/dX by relating it to the distribution of the Wigner-Smith time-delay matrix of a chaotic system. The distribution of dG/dX has a singularity at zero and algebraic tails. While G and dG/dX are correlated, the ratio of dG/dX and $\sqrt{G(1-G)}$ is independent of G. Coulomb interactions change the distribution of dG/dX, by inducing a transition from the grand-canonical to the canonical ensemble. All these predictions can be tested in semiconductor microstructures or microwave cavities.Comment: 4 pages, RevTeX, 3 figure

Performance optimization of large stroke flexure hinges for high stiffness and eigenfrequency

Two flexure hinge types are optimized for high support stiffness and high first unwanted eigenfrequency for two different working ranges, ±5.7° and ±20°. We show how multiple performance specifications lead to different designs with different performance. The optimization uses efficient parameterized non-linear beam-based models. The constraints and load case are taken from an electron microscopy use case. Optimization results show that the Three Flexure Cross Hinge has the highest first unwanted eigenfrequencies, while the new Infinity Flexure Hinge shows highest support stiffnesses. The design of the optimal geometry is detailed such that a prototype mechanism is manufactured and tested. Experiments show that the first unwanted eigenfrequency is 35 times higher than the first eigenfrequency throughout the working range

Density of states "width parity" effect in d-wave superconducting quantum wires

We calculate the density of states (DOS) in a clean mesoscopic d-wave superconducting quantum wire, i.e. a sample of infinite length but finite width $N$. For open boundary conditions, the DOS at zero energy is found to be zero if $N$ is even, and nonzero if $N$ is odd. At finite chemical potential, all chains are gapped but the qualtitative differences between even and odd $N$ remain.Comment: 7 pages, 8 figures, new figures and extended discussio

Demonstration of one-parameter scaling at the Dirac point in graphene

We numerically calculate the conductivity $\sigma$ of an undoped graphene sheet (size $L$) in the limit of vanishingly small lattice constant. We demonstrate one-parameter scaling for random impurity scattering and determine the scaling function $\beta(\sigma)=d\ln\sigma/d\ln L$. Contrary to a recent prediction, the scaling flow has no fixed point ($\beta>0$) for conductivities up to and beyond the symplectic metal-insulator transition. Instead, the data supports an alternative scaling flow for which the conductivity at the Dirac point increases logarithmically with sample size in the absence of intervalley scattering -- without reaching a scale-invariant limit.Comment: 4 pages, 5 figures; v2: introduction expanded, data for Gaussian model extended to larger system sizes to further demonstrate single parameter scalin