Multi-objective optimisation of machine tool error mapping using automated planning

Error mapping of machine tools is a multi-measurement task that is planned based on expert knowledge. There are no intelligent tools aiding the production of optimal measurement plans. In previous work, a method of intelligently constructing measurement plans demonstrated that it is feasible to optimise the plans either to reduce machine tool downtime or the estimated uncertainty of measurement due to the plan schedule. However, production scheduling and a continuously changing environment can impose conflicting constraints on downtime and the uncertainty of measurement. In this paper, the use of the produced measurement model to minimise machine tool downtime, the uncertainty of measurement and the arithmetic mean of both is investigated and discussed through the use of twelve different error mapping instances. The multi-objective search plans on average have a 3% reduction in the time metric when compared to the downtime of the uncertainty optimised plan and a 23% improvement in estimated uncertainty of measurement metric when compared to the uncertainty of the temporally optimised plan. Further experiments on a High Performance Computing (HPC) architecture demonstrated that there is on average a 3% improvement in optimality when compared with the experiments performed on the PC architecture. This demonstrates that even though a 4% improvement is beneficial, in most applications a standard PC architecture will result in valid error mapping plan

Adaptive Ising Model and Bacterial Chemotactic Receptor Network

We present a so-called adaptive Ising model (AIM) to provide a unifying explanation for sensitivity and perfect adaptation in bacterial chemotactic signalling, based on coupling among receptor dimers. In an AIM, an external field, representing ligand binding, is randomly applied to a fraction of spins, representing the states of the receptor dimers, and there is a delayed negative feedback from the spin value on the local field. This model is solved in an adiabatic approach. If the feedback is slow and weak enough, as indeed in chemotactic signalling, the system evolves through quasi-equilibrium states and the ``magnetization'', representing the signal, always attenuates towards zero and is always sensitive to a subsequent stimulus.Comment: revtex, final version to appear in Europhysics Letter

Coupled Cluster Treatment of the XY model

We study quantum spin systems in the 1D, 2D square and 3D cubic lattices with nearest-neighbour XY exchange. We use the coupled-cluster method (CCM) to calculate the ground-state energy, the T=0 sublattice magnetisation and the excited state energies, all as functions of the anisotropy parameter $\gamma$. We consider $S=1/2$ in detail and give some results for higher $S$. In 1D these results are compared with the exact $S=1/2$ results and in 2D with Monte-Carlo and series expansions. We obtain critical points close to the expected value $\gamma=0$ and our extrapolated LSUBn results for the ground-state energy are well converged for all $\gamma$ except very close to the critical point.Comment: 11 pages, Latex, 4 postscript figure, accepted by J.Phys.: Condens. Matte

The precursor to an industrial software metrics program

A common reason for why software metric programs dasiafailpsila is through lack of participant support and commitment. In this paper, we describe the results of a study which examined the knowledge that subjects had and the opinions they had formed of previous metrics initiatives in the same organization. The research was undertaken by one of the authors as a precursor to a planned metrics initiative in the same large, UK-based company. The study attempted to understand the likely issues that would have to be addressed by that planned metrics program. A key theme to emerge from the analysis was the importance of all participants being aware of the program objectives, and the purpose and use of the data being collected. As part of the analysis, the study also draws on the role that "timely" involvement plays within a metrics program and how that can influence its associated practicalities

Considering consumer choice in the economic evaluation of mandatory health programmes: A review

Objective: Governments are increasing their focus on mandatory public health programmes following positive economic evaluations of their impact. This review aims to examine whether loss of consumer choice should be included in economic evaluations of mandatory health programmes (MHP). Method: A systematic literature review was conducted to identify economic evaluations of MHP, whether they discuss the impact on consumer choice and any methodological limitations. Results: Overall 39 economic evaluations were identified, of which 10 discussed the loss of consumer choice and 6 attempted to place a value on the loss of consumer choice. Methodological limitations included: measuring the marginal cost of compliance, unavailability of price elasticity estimates, the impact of income effects, double counting health impacts, biased willingness-to-pay responses, and "protest" responses. Overall it was found that the inclusion of the loss of consumer choice rarely impacted on the final outcome of the study. Conclusion: The impact of MHP on the loss of consumer choice has largely been ignored in economic evaluations. Its importance remains uncertain due to its infrequent inclusion and significant methodological limitations. Further research regarding which methodology is best for valuing the loss of consumer choice and whether it is important to the final implementation decision is warranted. © 2010 Elsevier Ireland Ltd

Group Decision-Making: An Economic Analysis of Social Influence and Individual Difference in Experimental Juries

In a jury decision-making, individuals must compromise in order to reach a group consensus. If individuals compromise for non-rational reasons, such as a preference for conformity or due to erroneous information, then the final decision of the group may be biased. This paper presents original experimental data which shows that groups do have a significant tendency to compromise in jury-like settings. Econometric evidence also shows that features of groups, including the generosity of the group overall, will dictate the extent of compromise. The data also reveal that individual traits such as gender and capacity for empathy are associated with the extent of compromise in a jury-type setting. The implications are that interactions between individual and group characteristics limit the objectivity of decision-making

Shock Tube Determination of Autoionization Lifetime and Oscillator Strengths of the 352 3P 2Po-353P2 2S1/2 Doublet of Al I Scientific Report No. 2

Shock tube measurement of autoionization lifetime and oscillator strengths of states above first ionization potential for aluminu