Scoring the sum of correlated results in analytical proficiency testing

In proficiency tests the participants' results are usually converted into scores. In some schemes the participants are required to report the sum of the concentrations of a number of analytes and this total also is converted into a score. In such instances the scoring procedure for the total should be mathematically consistent with that for the separate analytes. When these analytes are determined from a single test portion, however, the errors in the results from a participant are likely to be correlated because some stages of the analysis are common to all of the analytes. For a consistent outcome, the scoring method must take account of such correlation

Nonlinear dynamic Interactions between flow-induced galloping and shell-like buckling

Acknowledgement The research of J.S. is supported by EPSRC Grant EP/J010820/1.Peer reviewedPublisher PD

Wired Up for Extra Value

The demand for Internet connectivity in office buildings opens up opportunities for landlords to provide added-value services to their tenants. This article seeks to explore the hypothesis that the provision of high bandwidth telecommunications to a building increases its value relative to buildings without this facility. The article builds upon research undertaken into existing use of the Internet over the past two years as evidence of demand for facilities and explores the likely impact of the provision of connectivity on different types of office. The connected building is defined and issues affecting its valuation analyzed. Finally, a hypothetical business model is constructed for a large multi-let building to demonstrate the likely income stream and timing that would be applicable.

Forward modelling of sub-photospheric flows for time-distance helioseismology

Context: The results of forward modelling of acoustic wave propagation in a realistic solar sub-photosphere with two cases of steady horizontal flows are presented and analysed by the means of local helioseismology. Aims: This paper is devoted to an analysis of the influence of steady flows on the propagation of sound waves through the solar interior. Methods: The simulations are based on fully compressible ideal hydrodynamical modelling in a Cartesian grid. The initial model is characterised by solar density and pressure stratifications taken from the standard Model S and is adjusted in order to suppress convective instability. Acoustic waves are excited by a non-harmonic source located below the depth corresponding to the visible surface of the Sun. Numerical experiments with coherent horizontal flows of linear and Gaussian dependences of flow speed on depth are carried out. These flow fields may mimic horizontal motions of plasma surrounding a sunspot, differential rotation or meridional circulation. An inversion of the velocity profiles from the simulated travel time differences is carried out. The inversion is based on the ray approximation. The results of inversion are then compared with the original velocity profiles. Results: The results of forward modelling of acoustic wave propagation in a realistic solar sub-photosphere with two cases of steady horizontal flows are presented. The influence of steady flow on the propagation of sound waves through the solar interior is analysed. A time-distance analysis technique is applied to compute the direct observable signatures of the background bulk motions on travel times and phase shifts. This approach allows direct comparison with observational data. Further, we propose a method of obtaining the travel-time differences for the waves propagating in sub-photospheric solar regions with horizontal flows. The method employs directly the difference between travel-time diagrams of waves propagating with and against the background flow. Conclusions: The analysis shows that the flow speed profiles obtained from inversion based on the ray approximation differ from the original ones. The difference between the original and observed profiles is caused by the fact that the wave packets propagate along the ray bundle, which has a finite extent, and thus reach deeper regions of the sub-photosphere in comparison with ray theory

THE REAL RATE OF PROTECTION: THE STABILIZING EFFECT OF PRICE POLICIES AND DIRECT PAYMENTS

Traditional indicators of protection refer to the level effect of price policies on income and ignore the stabilizing effect. We derive a measure of the real rate of protection which incorporates these dual dimensions. The income stabilizing effects of price policy protection lead to a greater level of real protection than would be measured conventionally. Computed real protection rates for the European Union wheat market over the pre- and post-MacSharry reform periods were found to be some 3-5 percent greater than traditional indicators. Moreover, the compensatory payments to farmers following the 1992 reforms had a major risk reducing impact.International Relations/Trade,

Effectiveness of Ninth-Grade Physics in Maine: Conceptual Understanding

The Physics First movement - teaching a true physics course to ninth grade students - is gaining popularity in high schools. There are several different rhetorical arguments for and against this movement, and it is quite controversial in physics education. However, there is no actual evidence to assess the success, or failure, of this substantial shift in the science teaching sequence. We have undertaken a comparison study of physics classes taught in ninth- and 12th grade classes in Maine. Comparisons of student understanding and gains with respect to mechanics concepts were made with excerpts from well-known multiple-choice surveys and individual student interviews. Results indicate that both populations begin physics courses with similar content knowledge and specific difficulties, but that in the learning of the concepts ninth graders are more sensitive to the instructional method used.Comment: 15 pages, 2 tables, 0 figures, to be published in The Physics Teache