Estimating bedrock depth in the case of regolith sites using ambient noise analysis

Subsurface geometry, particularly the depth of bedrock, is crucial in seismic hazard studies because the basin geometry has been shown to play an important role in the altering of seismic waves. Estimating the bedrock surface using ambient seismic noise analysis has been undertaken by many researchers, with most studies focusing on sites with a strong impedance contrast between the bedrock and the overlying materials. The application of this technique at regolith sites, which is subjected to impedance contrasts in the low to high range is underdeveloped and requires further attention. This study seeks to address this need and is focused on the city of Adelaide in South Australia, which exhibits site amplification and is associated with various impedance contrasts. Analyses of ambient noise data are carried out using the generic function (GF) of the classic horizontal vertical spectral ratio (HVSR) method and the spatial autocorrelation (SPAC) technique to estimate the depth to bedrock. Comparison of the bedrock depth predictions from the seismic methods with boreholes drilled in close proximity to the measured sites demonstrate that the SPAC method provides superior estimates especially to those obtained from the other approach. This work demonstrates that the microtremor SPAC method is an effective tool for estimating bedrock structure at regolith sites.Bambang Setiawan, Mark Jaksa, Michael Griffith, David Lov

Networking and innovation: a systematic review of the evidence

Porter and Ketels' (2003) study of British competitiveness emphasised the importance of business networking for innovativeness. Until recently insights into the dynamics of this relationship have been fragmented. This paper presents a systematic review of research linking the networking behaviour of firms with their innovative capacity. We find that the principal benefits of networking as identified in the literature include, risk sharing; obtaining access to new markets and technologies; speeding products to market; pooling complementary skills; safeguarding property rights when complete or contingent contracts are not possible; and acting as a key vehicle for obtaining access to external knowledge. The evidence also illustrates that those firms which do not cooperate and which do not formally or informally exchange knowledge limit their knowledge base on a long-term basis and ultimately reduce their ability to enter into exchange relationships. At an institutional level, national systems of innovation play an important role in the diffusion of innovations in terms of the way in which they shape networking activity. The paper provides evidence suggesting that network relationships with suppliers, customers, and intermediaries such as professional and trade associations are important factors affecting innovation performance and productivity. Where networks fail it is due to inter-firm conflict, displacement, lack of scale, external disruption and lack of infrastructure. The review identifies several gaps in the literature that need to be filled. For instance, there is a need for further exploration of the relationship between networking and different forms of innovation, such as, process and organisational innovation. Similarly, we need better understanding of network dynamics and network configurations, as well as the role of third parties such as professional and trade associations. Our study highlights the need for inter-disciplinary research in these areas