Innovation at the end of the life cycle: discontinuous innovation strategies by incumbents

This paper focuses on the strategies of incumbents that seek to develop discontinuous innovations within the boundaries of a mature innovation system. Mature innovation systems do not provide support for these discontinuous innovations. This article focuses on exploring why incumbents in these setting engage in discontinuous innovation and what strategies they deploy to become successful. We analyse 10 cases of incumbents developing discontinuous innovations in the mature Dutch greenhouse horticulture sector. The results of our analysis show that the incumbents are primarily triggered by dissatisfaction with the current way of doing business and that the existing institutions are the main barrier to discontinuous innovation. In response, the incumbents try to circumvent the existing innovation system in their innovation process, but when successful also engage in changing the existing innovation system. This paper contributes to the understanding of the role of incumbents as source of discontinuous innovation in mature innovation systems.     

Robust Evolutionary Algorithm Design for Socio-economic Simulation

Agent-based computational economics (ACE) combines elements from economics and computer science. In this paper, we focus on the relation between the evolutionary technique that is used and the economic problem that is modeled. In the field of ACE, economic simulations often derive parameter settings for the evolutionary algorithm directly from the values of the economic model parameters. In this paper, we compare two important approaches that are dominating ACE research and show that the above practice may hinder the performance of the evolutionary algorithm and thereby hinder agent learning. More specifically, we show that economic model parameters and evolutionary algorithm parameters should be treated separately by comparing the two widely used approaches to social learning with respect to their convergence properties and robustness. This leads to new considerations for the methodological aspects of evolutionary algorithm design within the field of ACE.     

Is cluster policy useful for the energy sector? Assessing self-declared hydrogen clusters in the Netherlands

Research on science-based industries has shown that it is important for organisations to be active in interorganisational networks. Cluster policy has been developed as a means to stimulate the development of these networks and thereby the success rate of these industries. Cluster policy is however not a common policy instrument in the energy sector. In this paper, we focus on three self-declared clusters active in hydrogen-related R&D in the Netherlands and address several characteristics of these clusters. We conclude that cluster policy is a useful addition to existing energy R&D policies but that monitoring whether self-declared clusters actually function as clusters and what their contribution is to the overall system is pivotal in reaping the benefits of cluster policy.     

Immunohistochemical localization of SKALP/elafin in psoriatic epidermis

Recently we have reported the purification and biochemical characterization of a new, inducible elastase inhibitor [skin-derived antileukoproteinase (SKALP)], which could be extracted in high amounts from psoriatic skin but not from normal human skin. Here we demonstrate the immunohistochemical localization of SKALP in psoriatic epidermis. SKALP was found exclusively in the upper layers of the suprabasal compartment and stratum corneum of lesional psoriatic epidermis. Basal keratinocytes were always negative. No immunoreactive SKALP was found in normal epidermis and non-lesional psoriatic epidermis, in accordance with findings in functional assays. Western blots of skin extracts from psoriatic and normal skin confirmed the immunohistochemical findings and revealed two major bands with apparent molecular weights of 10.5 and 11.5 kDa. We would hypothesize that SKALP could act as a modulator of epidermal inflammation by interfering with polymorphonuclear leukocyte trafficking, and that it could protect structural proteins against elastase-mediated damage.     

Effect of post‐deposition treatments on the hydrogenation of hot‐wire deposited amorphous silicon films

The effect of different post‐deposition treatments on the structure of Hot‐Wire (HW) deposited intrinsic a‐Si:H thin films is investigated. These treatments are applied in order to rehydrogenate the top region of the film, which, due to the high deposition temperatures of these films, becomes depleted of hydrogen. Using secondary ion mass spectroscopy (SIMS) for measurement of the hydrogen profiles and Raman spectroscopy measurements to investigate the hydrogen bonding configuration at the surface, we were able to determine the effect of the different treatments on the films. We show that the hydrogen profile in the subsurface region is not a result of the out‐diffusion of hydrogen while the sample is cooled down after the deposition, but develops during the growth of the film. The most effective bulk rehydrogenation is achieved with an atomic hydrogen treatment, for which we determined a diffusion coefficient for atomic hydrogen of 7×10⁻¹⁴ cm² s⁻¹ at 430°C. Rapid cooling and a hydrogen plasma treatment are shown to result in an improved top surface hydrogenation of the intrinsic film. Despite the differences in top surface hydrogenation of the intrinsic films, application of the treatments in real n‐i‐p solar cell devices did not show an improvement in the cell properties. We attribute this to the existence of defects deeper in the bulk of the intrinsic layer or at the n/i‐interface, being the dominating effect that limits the cell performance. Copyright © 1999 John Wiley & Sons, Ltd.     

Poly-silicon films with low impurity concentration made by hot wire chemical vapour deposition

Analyses of various impurities (O, C, W, Fe, Ni and Cr) in the poly-Si material (both in layers as well as in cell configurations) made by HWCVD have been carried out to judge the quality of this material for application in devices. SIMS analysis showed that the oxygen concentration in the bulk of a poly-Si film made at a low hydrogen dilution (Poly2) is 3×10¹⁸ cm⁻³ and the oxygen content drops to this value within a depth of only 50 nm from the surface. On the other hand, a poly-Si film made at a high hydrogen dilution (Poly1) has a high and homogeneous oxygen content of more than 2×10²¹ cm⁻³. However, in a double-layer structure (Poly2 on top of Poly1), the oxygen content of the bottom layer (Poly1) is significantly smaller than the bare Poly1 film, though this oxygen concentration is still much higher than that in the top Poly2 layer. We attribute this behaviour to the structural difference between these two films (2000 cm⁻¹ Si–H IR vibration in low-dilution material and 2100 cm⁻¹ vibration in the high-dilution material). We propose that the oxygen penetration in Poly1 occurs by two processes: (1) oxygen incorporation during growth: (2) post-deposition oxygen intrusion. The first process occurs at a low deposition rate and is dependent on the type of growth process. The second process is due to the intrusion of water vapour into the film through the voids, which increases the conductivity of the film depending on the amount of intrusion. We have shown that our device quality compact poly-Si : H (Poly2) resists oxygen incorporation even when deposited in an oxygen-rich atmosphere.     

Imaging and nanofabrication with the helium ion microscope of the Van Leeuwenhoek Laboratory in Delft

Although helium ion microscopy (HIM) was introduced only a few years ago, many new application fields are emerging. The connecting factor between these novel applications is the unique interaction of the primary helium ion beam with the sample material at and just below its surface. In particular, the HIM secondary electron signal stems from an area that is extremely well localized around the point of incidence of the primary beam. This makes the HIM well suited for both high-resolution imaging and high-resolution nanofabrication. Another advantage in nanofabrication is the low ion backscattering fraction, which leads to a weak proximity effect. The subnanometer probe size and the unique beam-materials interactions have opened new areas of research. This review presents a selection of studies conducted on a single instrument. The selection encompasses applications ranging from imaging to nanofabrication and from fundamental academic research to applied industrial developments.