Multiprocessing techniques for unmanned multifunctional satellites Final report,

Simulation of on-board multiprocessor for long lived unmanned space satellite contro

The effectiveness of refactoring, based on a compatibility testing taxonomy and a dependency graph

In this paper, we describe and then appraise a testing taxonomy proposed by van Deursen and Moonen (VD&M) based on the post-refactoring repeatability of tests. Four categories of refactoring are identified by VD&M ranging from semantic-preserving to incompatible, where, for the former, no new tests are required and for the latter, a completely new test set has to be developed. In our appraisal of the taxonomy, we heavily stress the need for the inter-dependence of the refactoring categories to be considered when making refactoring decisions and we base that need on a refactoring dependency graph developed as part of the research. We demonstrate that while incompatible refactorings may be harmful and time-consuming from a testing perspective, semantic-preserving refactorings can have equally unpleasant hidden ramifications despite their advantages. In fact, refactorings which fall into neither category have the most interesting properties. We support our results with empirical refactoring data drawn from seven Java open-source systems (OSS) and from the same analysis form a tentative categorization of code smells

Product market competition and corporate governance disclosure: evidence from the UK

In this study we measure multiple dimensions of product market competition and examine their impacts on corporate governance disclosure, based on a sample of UK public firms over the period 2001 to 2009. We use factor analysis to explore the different dimensions of product market competition; and regression models to analyse the association between multiple dimensions of product market competition and corporate governance disclosure. We find that firms in less competitive industries have significantly more corporate governance disclosure. Furthermore, we detect a positive association between corporate governance disclosure and board independence, as well as audit committee independence. This suggests that firms with better corporate governance tend to disclose more information to external investors. Overall the findings support the view that managers use more corporate governance disclosure as a substitute for the external disciplinary force of product market competition

Available energy of the world ocean

The available energy of the ocean is the excess of the sum of the ocean\u27s internal and gravitational energies with respect to its equilibrium state, which is in thermodynamic equilibrium and has the same total entropy as the ocean. The equilibrium state for the world ocean is rigorously determined to be an isothermal ocean with a temperature of 3.66˚C and a horizontally uniform absolute salinity that increases monotonically from 27.30 g kg–1 at the surface to 47.39 g kg–1 at a depth of 5.5 km. This salinity profile is consistent with a uniform relative chemical potential of 47.44 J g–1 salt. The ocean\u27s available energy is 220 × 1021 J or 630 MJ m–2. Most (72%) of the available energy is due to the internal energy difference between the ocean and its equilibrium state; the remaining 28% is due to the gravitational energy difference. The ocean\u27s available energy is shown to be concentrated vertically in the upper half kilometer and geographically in the tropics and subtropics. This distribution is accurately represented by the temperature variance from the equilibrium temperature. The contributions of sea ice and variable sea surface height to the available energy are estimated to be small

Investigation of contact of metrological probe tips with rough engineering surfaces

This investigation explores the behaviour of contact interaction between probe tips of indicators (displacement gauges) and rough engineering surfaces, in order to gain new insights into uncertainty in industrial precision gauging. The conditions of interest are contact of a mm-scale hard sphere at 0.1 to 5 N force with metallic surfaces, Rq < 2 mm. The motivation arises from the growing demand of modern industries for higher machining processes and for finer inspection capabilities. In the near future, such a demand is likely to require careful analyses of the measurement error budget of these instruments with a greater consideration of the potential errors induced by the complex behaviour of contact, which is currently assumed to be negligible. A preliminary experimental study was carried out on an existing test-rig of limited accuracy. It raised several concerns related to the effects of surface roughness and material on the resulting contact deflection at the load regimes of indicators’ probes. It stimulated the need for more reliable data. So, a new test-rig of advanced capabilities was designed to perform a comprehensive study of a wider range of contact parameters to simulate real situations of industrial gauging processes. This advanced study confirms the consistent effects of roughness, material and probe tip size not only on the surface deflections but also on the probe rotations. Roughness variability across the same surface caused some inconsistencies in the deflection behaviour and repeatability, and surface contamination gave additional unsystematic effects on these relations. Re-establishing contact on the same position of a contaminated surface appeared to contribute errors of the order of those of a clean surface. Based on the results of this investigation, systematic errors of contact can exceed the 1 mm level with uncertainty up to at least 0.4 mm in many measurement processes with precision indicators. Such figures reveal that the contact cannot any longer be considered a negligible source of errors, and precision metrology must account for these induced errors in the budget of displacement gauges

Reply to "Comment on `Lattice determination of Sigma - Lambda mixing' "

In this Reply, we respond to the above Comment. Our computation [Phys. Rev. D 91 (2015) 074512] only took into account pure QCD effects, arising from quark mass differences, so it is not surprising that there are discrepancies in isospin splittings and in the Sigma - Lambda mixing angle. We expect that these discrepancies will be smaller in a full calculation incorporating QED effects.Comment: 5 page

A lattice determination of Sigma - Lambda mixing

Isospin breaking effects in baryon octet (and decuplet) masses are due to a combination of up and down quark mass differences and electromagnetic effects and lead to small mass splittings. Between the Sigma and Lambda this mass splitting is much larger, this being mostly due to their different wavefunctions. However when isospin is broken, there is a mixing between between these states. We describe the formalism necessary to determine the QCD mixing matrix and hence find the mixing angle and mass splitting between the Sigma and Lambda particles due to QCD effects.Comment: 40 pages, 5 figures, published versio