Approximation orders of shift-invariant subspaces of W2s(Rd)W^s_2({\Bbb R}^d)

We extend the existing theory of approximation orders provided by shift-invariant subspaces of $L_2$ to the setting of Sobolev spaces, provide treatment of $L_2$ cases that have not been covered before, and apply our results to determine approximation order of solutions to a refinement equation with a higher-dimensional solution space.Comment: 49 page

Box spline prewavelets of small support

The purpose of this paper is the construction of bi- and trivariate prewavelets from box-spline spaces, \ie\ piecewise polynomials of fixed degree on a uniform mesh. They have especially small support and form Riesz bases of the wavelet spaces, so they are stable. In particular, the supports achieved are smaller than those of the prewavelets due to Riemenschneider and Shen in a recent, similar constructio

Incentives to innovate

This empirical study investigates the factors that influence firms' incentives to innovate. We study the variables stimulating, enabling and conditioning the idea generation process in small and medium-sized service firms. The employees and their context determine the richness of the early stages of the innovation process, and thus the firms' incentives to innovate. Of the final set of explanatory variables, the most significant 'manageable' variable is the formulation of clear innovation objectives in the corporate strategy. Furthermore, fostering freedom to experiment and applying multifunctional teams have positive effects on the incentives to innovate. Besides, two factors (quality competition and high� uncertainty of market demand) are market related. Finally, in contradiction to our expectations, having well-educated employees has a negative effect on the incentives to innovate.

Determinants of innovative ability

Deze strategische verkenning gaat in op de vraag welke factoren bepalend zijn voor het innovatievermogen van dienstverlenende bedrijven met 10 tot 100 werknemers. Voor deze bedrijven is de invloed van 38 factoren op het innovatievermogen onderzocht.

The Dynamics of Interfirm Networks along the Industry Life Cycle: The Case of the Global Video Games Industry 1987-2007

In this paper, we study the formation of network ties between firms along the life cycle of a creative industry. We focus on three drivers of network formation: i) network endogeneity which stresses a path-dependent change originating from previous network structures, ii) five forms of proximity (e.g. geographical proximity) which ascribe tie formation to the similarity of actors' attributes; and (iii) individual characteristics which refer to the heterogeneity in actors capabilities to exploit external knowledge. The paper employs a stochastic actor-oriented model to estimate the - changing - effects of these drivers on inter-firm network formation in the global video game industry from 1987 to 2007. Our findings indicate that the effects of the drivers of network formation change with the degree of maturity of the industry. To an increasing extent, video game firms tend to partner over shorter distances and with more cognitively similar firms as the industry evolves.network dynamics, industry life cycle, proximity, creative industry, video game industry, stochastic actor-oriented model

Innovation and firm performance

Understanding the relation between innovation and performance in both large, medium, and small firms is of crucial importance for ongoing economic growth, but still hardly understood. The topic of understanding innovations and their relationship with firm performance has become more relevant since the EU stated, in March 2000 in Lisbon, the ambition to become the world's most competitive and innovative region by 2010. The underlying rationale is that encouraging firms to innovate will lead to a better economic performance; higher growth, more jobs and higher wages. Is this rationale empirically validated, and is there a preferential one-size-fits-all innovation trajectory for all European companies? The objective of this paper is to depict the current state of knowledge regarding the relation between innovation and performance in general, and for SMEs in particular.

Innovation and firm performance

In this paper, the current state of knowledge regarding the relation between innovation and firm performance is reviewed. The relationship is empirically tested. There is a special focus on small and medium-sized firms. In the literature, there is a trend towards a system approach. Empirical studies using this approach distinguish four parts in the innovation-performance relationship. First of all, a company decides whether or not to innovate. Secondly, if a company decides to innovate, what is the level of input in innovation. The innovative input will be transformed into innovative output. And finally, the innovative output will result in a better firm performance. In the model several feedback loops are incorporated, for instance, from firm performance to innovative input.

Protein crops: Food and feed for the future [Editorial]

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