Noun and adjective imagery and order in paired-associate learning by French and English subjects.

Varied rated noun imagery (I), rated adjective I, and noun-adjective order in a paired-associate (PA) learning task. 98 10th graders learned 2 PA lists, 1 with noun-adjective (N-A) pairs and 1 with adjective-noun (A-N) pairs. Within each list rated I of both nouns and adjectives was varied factorially. Both English- and French-speaking Ss learned the lists in their own languages. Results support the predictions from an hypothesis based on mediating imagery. N-A recall was superior to A-N recall for all combinations of word I, except when nouns were low and adjectives high in I. In the latter case, A-N recall was higher. This pattern was the same for both English- and French-speaking Ss. Results are interpreted as further evidence of the important role played by imagery in verbal learning. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrete Convolution in Power System Reliability

This paper describes a general method for convolving discrete distributions using Fast Fourier Transforms. It can be used in evaluating reliability of any system involving discrete or discretised convolution. It has been used in power system studies to deduce capacity-outage probability tables and to solve probabilistic load flows. These studies have shown it to be much less time-consuming and more efficient than the conventional direct methods. The method is used in the paper to evaluate the loss of load probability of a generating system in order to demonstrate the method's application and inherent merits.     

Extraction of titanium dioxide (TiO2) from ilmenite and titaniferous slag

Solutions of ilmenite (FeTiO₃) and a titaniferous slag, in fused Li₂O. 2B₂O₃ and Li₂O. 4B₂O₃, yield on cooling compounds tentatively identified as LiFe₂.₅Ti₃O₉ and Li₂Fe₃Ti₂.₅O₉ respectively. Both compounds are orthorhombic, and have the pseudobrookite structure. The ilmenite solutions yield, in addition, rutile (TiO₂). The yield of rutile increases from about 1 to 24% (w/w) of the products, when the solvent is changed from Li₂O. 2B₂O₃ to Li₂O. 4B₂O₃. Substitution of K₂O. 4B₂O₃ for the latter solvent decreases the yield of rutile to c. 10%. The yield of rutile is approximately in inverse proportion to the Lux—Flood basicity of the borate solvent.     

Pupillary dilation and mediation processes during paired-associate learning.

Describes 2 experiments with 54 undergraduates in which pupillary activity was continuously photographed during mediator-formation and paired-associate (PA) learning tasks involving nouns as items. Abstractness-concreteness of the nouns and mediation instructions (imagery, verbal, or none) were varied. The magnitude and latency of pupillary dilation as well as task performance were measured. The PA recall data confirm previous findings in showing strong positive effects of concreteness, especially as a stimulus variable. Learning was generally best under the imagery mediation set, its superiority over the verbal mediation condition being greatest in the case of pairs with abstract stimulus members. Pupil size during learning was largest when no mediation instructions were given and when stimulus members were abstract, supporting an interpretation of pupillary dilation as an index of cognitive task difficulty. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A time-space tradeoff for sorting on non-oblivious machines

A model of computation is introduced which permits the analysis of both the time and space requirements of non-oblivious programs. Using this model, it is demonstrated that any algorithm for sorting n inputs which is based on comparisons of individual inputs requires time-space product proportional to n².     

The influence of a back support harness on spinal forces during sheep shearing

Previous research has classified the occupation of sheep shearing as heavy work where shearers flex their spine and hips for long periods of time, handle awkward loads and expend high amounts of energy. The aim of this research was to investigate the magnitude of spinal forces produced during the shearing phase of the work and to determine whether the use of a commercially available back support harness would reduce these forces. Following discussion on task complexity and risk of back injury with senior shearing instructors, three component tasks of the shearing phase were identified as posing high risk of injury and were prioritized for primary analysis. Although the dragging out of a sheep in preparation for shearing and an unexpected loss of animal control were also identified as being of high risk, technological and instrumentation difficulties precluded their analysis. Twelve experienced shearers were videotaped while shearing with and without the use of a back harness. Surface mounted retro-reflective markers placed on the trunk defined three linked segments: Pelvis, Lumbar and Head, Arms, and Upper Trunk (HAUT). A 3D, link segment, top down, inverse dynamics approach was used to describe the motion and to estimate forces involved during the identified tasks of shearing. The spinal force/time profiles of this sample of shearers demonstrated large compressive and shear forces for all three tasks that are close to the NIOSH and University of Waterloo action limits for compressive and shear forces respectively (McGill 1997, Yingling and McGill 1999, Marras 2000). The use of the back support harness reduced these forces by substantial and statistically significant amounts. This effect was consistent across all three tasks. The results of this study demonstrate the production of high levels of compressive and shear forces within the spine of shearers during the three shearing tasks studied and that the use of a back support harness can substantially reduce these forces. Therefore the use of a back harness may reduce the cumulative load on the spine during shearing thereby moderating damage to the articular structures. However it is not known whether the harness would protect the spine from a sudden or unexpected force.     

The Power of Priority Algorithms for Facility Location and Set Cover

We apply and extend the priority algorithm framework introduced by Borodin, Nielsen, and Rackoff to define greedy-like algorithms for the (uncapacitated) facility location problems and set cover problems. These problems have been the focus of extensive research from the point of view of approximation algorithms and for both problems greedy-like algorithms have been proposed and analyzed. The priority algorithm definitions are general enough to capture a broad class of algorithms that can be characterized as greedy-like while still possible to derive non-trivial lower bounds on the approximability of the problems by algorithms in such a class. Our results are orthogonal to complexity considerations, and hence apply to algorithms that are not necessarily polynomial time.     

Dual source fourier transform polarization modulation spectroscopy: an improved method for the measurement of circular and linear dichroism

It is shown that the use of two sources in a four-port interferometer equipped with cube-corner mirrors leads to increased signal-to-noise ratios in Fourier transform (FT-IR) circular and linear dichroism spectra. The output beam to the sample is a superposition of two interferograms, one from each source, having opposite Fourier phases. These two interferograms cancel one another to the degree that the two sources are matched in intensity. If the radiation from each of the two sources is first polarized orthogonally with respect to the other and passed through a polarization modulator before reaching the sample, the resulting polarization-modulation interferograms are out of Fourier phase and out of polarization-modulation phase. As a result, the polarization-modulation interferograms, due to circular or linear dichroism in the sample, from the two sources combine positively rather than negatively. An improvement in signal-to-noise ratio of up to two (or a factor of four in scan-time reduction for the same signal-to-noise ratio) compared to single source operation can be realized, while at the same time, the potential for saturation of the detector signal is significantly reduced due to the reduction in magnitude of the combined ordinary infrared transmission interferogram. Absorption and circular dichroism spectra from a dual-source FT-IR spectrometer are presented and analyzed.