Composite "zigzag" structures in the 1D complex Ginzburg-Landau equation

We study the dynamics of the one-dimensional complex Ginzburg Landau equation (CGLE) in the regime where holes and defects organize themselves into composite superstructures which we call zigzags. Extensive numerical simulations of the CGLE reveal a wide range of dynamical zigzag behavior which we summarize in a `phase diagram'. We have performed a numerical linear stability and bifurcation analysis of regular zigzag structures which reveals that traveling zigzags bifurcate from stationary zigzags via a pitchfork bifurcation. This bifurcation changes from supercritical (forward) to subcritical (backward) as a function of the CGLE coefficients, and we show the relevance of this for the `phase diagram'. Our findings indicate that in the zigzag parameter regime of the CGLE, the transition between defect-rich and defect-poor states is governed by bifurcations of the zigzag structures.Comment: 20 pages, 11 figure

Pareto plot threshold for multiple factors in design of experiments

Economical, technical and strategic reasons make unreplicated experimental designs necessary and popular in industrial and management settings. This paper investigates the legitimate use of well known methods that appoint effects as significant when they are larger than a defined threshold. We found that established estimation methods, such as Lenth's method and Dong's method, are too tolerant and a larger threshold should be used before an effect can be determined as influencing. This comparing analysis was done by using the degree of freedom that is available when the resolution of the design is one less than the maximum value. Using the Pareto Principle we suggest a more accurate threshold estimator for significantly influencing factors and/or interactions based on analysis of variance

Time series analysis to forecast temperature change

ARIMA models are often used to model the evolution in time of economic issues. We demonstrate that an ARIMA model is also valuable in the environmental field, where the evolution of climate change is causing many concerns. Can we confirm the global warming by mathematical prediction theories

High-order convergent deferred correction schemes based on parameterized Runge-Kutta-Nyström methods for second-order boundary value problems

AbstractIterated deferred correction is a widely used approach to the numerical solution of first-order systems of nonlinear two-point boundary value problems. Normally, the orders of accuracy of the various methods used in a deferred correction scheme differ by 2 and, as a direct result, each time deferred correction is used the order of the overall scheme is increased by a maximum of 2. In [16], however, it has been shown that there exist schemes based on parameterized Runge–Kutta methods, which allow a higher increase of the overall order. A first example of such a high-order convergent scheme which allows an increase of 4 orders per deferred correction was based on two mono-implicit Runge–Kutta methods. In the present paper, we will investigate the possibility for high-order convergence of schemes for the numerical solution of second-order nonlinear two-point boundary value problems not containing the first derivative. Two examples of such high-order convergent schemes, based on parameterized Runge–Kutta-Nyström methods of orders 4 and 8, are analysed and discussed

Towards an audiovisual media services directive: an analysis of the Commission's proposal. Egmont European Affairs Publication, 2006

The current “Television without frontiers” (TVWF) Directive constitutes the basic regulation of the European Community’s broadcasting policy. Adopted in 1989, the Directive provides for the free movement of television broadcasting services in the Union as it requires Member States to guarantee the freedom of reception and transmission on their territory of television programmes which originate from other Member States. Consequently, the Directive harmonized certain national programming and advertising rules. With the aim of protecting the European TV market, it also introduced broadcasting quota for European and independent works. In the light of the rapid developments in the television sector, a revision of the Directive took place in 1997. Since 2002, the Commission is engaged in a new revision process in order to modernise the rules on televised services. It has also examined the possibility to extend the scope of these rules to cover all services which have an audiovisual content, including new media services delivered by Internet, email, mobile communication, etc. On 13 December 2005, the Commission eventually adopted the legislative proposal for the revision of the Directive. The aim of this paper is to analyse the Commission’s strategy in reviewing the regulatory framework. First, we will shortly discuss and evaluate the underlying principles of the present Directive. We will subsequently take a look at the elements which require a revision of the Directive. Third, we will examine the Commission’s proposal and we will conclude with some critical comments