19,774 research outputs found
Service Performance Indicators for Infrastructure Investment
Infrastructure systems serving modern economies are highly complex, highly interconnected, and often highly
interactive. The result is increased complexity in investment decision-making, and increased challenges in prioritising
that investment. However, this prioritisation is vital to developing a long-term, sound, robust and achievable pipeline
of national infrastructure.
One key to effective, objective and prudent investment prioritisation is understanding the real performance of
infrastructure. Many metrics are employed to this end, and many are imposed by governments or regulators, but
often these metrics relate only to inputs or outputs in a production process. Whilst these metrics may be useful for
delivery agencies, they largely fail to address the real expectations or requirements of infrastructure users — quality of
service, safety, reliability, and resilience.
What is required is a set of metrics which address not outputs but outcomes — that is, how well does the
infrastructure network meet service needs? This paper reports on a study undertaken at a national level, to identify
service needs across a range of infrastructure sectors, to assess service performance metrics in use, and to show
how they or other suitable metrics can be used to prioritise investment decisions across sectors and jurisdictions
Bifurcations from families of periodic solutions in piecewise differential systems
Consider a differential system of the form where
and are piecewise
functions and -periodic in the variable . Assuming that the unperturbed
system has a -dimensional submanifold of periodic solutions
with , we use the Lyapunov-Schmidt reduction and the averaging theory to
study the existence of isolated -periodic solutions of the above
differential system
Evidence of spontaneous spin polarized transport in magnetic nanowires
The exploitation of the spin in charge-based systems is opening revolutionary
opportunities for device architecture. Surprisingly, room temperature
electrical transport through magnetic nanowires is still an unresolved issue.
Here, we show that ferromagnetic (Co) suspended atom chains spontaneously
display an electron transport of half a conductance quantum, as expected for a
fully polarized conduction channel. Similar behavior has been observed for Pd
(a quasi-magnetic 4d metal) and Pt (a non-magnetic 5d metal). These results
suggest that the nanowire low dimensionality reinforces or induces magnetic
behavior, lifting off spin degeneracy even at room temperature and zero
external magnetic field.Comment: 4 pages, 3 eps fig
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