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Accountability and performance management systems within private and public sector organisational change processes
No full textThis paper examines organisational change processes that occur when accountability demands from powerful external stakeholders change. It investigates, firstly, whether these external accountability demands impact on the performance management systems of two different types of organisations. Secondly, it considers whether the goals for improved performance contained within the external accountability demands are realised. The paper derives its primary insights from analysing in-depth interviews with managers working in a private sector company and in public sector organisations. The analyses reveal complex organisational responses. In the public sector case study, the organisations tended to reorient their performance management systems towards the external accountability demands; whilst in the private sector organisation, pressures from falling share prices forced managers to focus their decision making on the preferred performance measures contained in shareholders’ accountability demands. However, whilst there is some evidence of performance management system changes, the desires for improved performance subsumed by the external accountability demands are not necessarily realised through the performance management system changes
On the classifying space for the family of virtually cyclic subgroups for elementary amenable groups
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A Penrose polynomial for embedded graphs
No full textWe extend the Penrose polynomial, originally defined only for plane graphs, to graphs embedded in arbitrary surfaces. Considering this Penrose polynomial of embedded graphs leads to new identities and relations for the Penrose polynomial which can not be realized within the class of plane graphs. In particular, by exploiting connections with the transition polynomial and the ribbon group action, we find a deletion-contraction-type relation for the Penrose polynomial. We relate the Penrose polynomial of an orientable checkerboard colourable graph to the circuit partition polynomial of its medial graph and use this to find new combinatorial interpretations of the Penrose polynomial. We also show that the Penrose polynomial of a plane graph G can be expressed as a sum of chromatic polynomials of twisted duals of G. This allows us to obtain a new reformulation of the Four Colour Theorem
Enhancing multiphoton rates with quantum memories
No full textSingle photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this `scaling catastrophe'. Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity as the most important figure of merit in this connection, where and are the efficiency and time-bandwidth product of the memories, respectively
Enhancing multiphoton rates with quantum memories
Get PDFSingle photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using non-deterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this `scaling catastrophe'. Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity as the most important figure of merit in this connection, where and are the efficiency and time-bandwidth product of the memories, respectively
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