261 research outputs found
The effect of category variability in perceptual categorization
No full textExemplar and distributional accounts of categorization make differing predictions for the classification of a critical exemplar precisely halfway between the nearest exemplars of 2 categories differing in variability. Under standard conditions of sequential presentation, the critical exemplar was classified into the most similar, least variable category, consistent with an exemplar account. However, if the difference in variability is made more salient, then the same exemplar is classified into the more variable, most likely category, consistent with a distributional account. This suggests that participants may be strategic in their use of either strategy. However, when the relative variability of 2 categories was manipulated, participants showed changes in the classification of intermediate exemplars that neither approach could account for
Fabrication and characterization of free-standing thick-film piezoelectric cantilevers for energy harvesting
No full textResearch into energy harvesting from ambient vibration sources has attracted great interest over the last few years, largely as a result of advances in the areas of wireless technology and low power electronics. One of the mechanisms for converting mechanical vibration to electrical energy is the use of piezoelectric materials, typically operating as a cantilever in a bending mode, which generate a voltage across the electrodes when they are stressed. Typically, the piezoelectric materials are deposited on a non-electro-active substrate and are physically clamped at one end to a rigid base. The presence of the substrate does not contribute directly to the electrical output, but merely serves as a mechanical supporting platform, which can pose difficulties for integration with other microelectronic devices. The aim of this paper is to describe a novel thick-film free-standing cantilever structure that does not use a supporting platform and has the advantage of minimising the movement constraints on the piezoelectric material, thereby maximising the electrical output power. Two configurations of composite cantilever structure were investigated; unimorph and multimorph. A unimorph consists of a pair of silver/palladium (Ag/Pd) electrodes sandwiching a laminar layer of lead zirconate titanate (PZT). A multimorph is an extended version of the unimorph with two pairs of Ag/Pd electrodes and three laminar sections of PZT
Universal generalization and universal inter-item confusability
No full textWe argue that confusability between items should be distinguished from generalization between items. Shepard's data concern confusability, but the theories proposed by Shepard and by Tenenbaum & Griffiths concern generalization, indicating a gap between theory and data. We consider the empirical and theoretical work involved in bridging this gap
Similarity and dissimilarity as evidence in perceptual categorization
No full textIn exemplar models the similarities between a new stimulus and each category exemplar constitute positive evidence for category membership. In contrast, other models assume that, if the new stimulus is sufficiently dissimilar to a category member, then that dissimilarity constitutes evidence against category membership. We propose a new similarity–dissimilarity exemplar model that provides a framework for integrating these two types of accounts. The evidence for a category is assumed to be the summed similarity to members of that category plus the summed dissimilarity to members of competing categories. The similarity–dissimilarity exemplar model is shown to mimic the standard exemplar model very closely in the unidimensional domain
Harpur Palate, Volume 5 Issue 2, Winter 2006
No full textContributors: Amanda Auchter | Margaret A. Robinson |Linda Dove |Kate Beles | Lori Anderson Moseman | Andrew Farkas | Thom Ward | Doug Ramspeck | Farrah Field | James Doyle | Anne Germanacos | T. J. Beitelman | Neil Shepard | Jaimee Wriston Colbert | Eric Rawson | Rachel Eliza Griffiths | Bradford Gray Telford | Richard Robbins | Otis Bardwell | Viet Dinh | Dara Mandle | Peter B. Hyland | E. R. Turner | Eric Cotts, Lawrence Lehman, Yan Xiang | Victoria Boynton | Dara-Lyn Shrager | Amy Spade | Ed Zahniser | Thomas Miller | Tom Haushalter | Judith Harris | Michael Steinberg | Roxana Cazan | Sarah Klenbort | Sean Thomas Dougherty | Renée E. D\u27Aoust | Matthew A. Ricke | Pablo Miguel MartÍne
Decision by sampling
No full textWe present a theory of decision by sampling (DbS) in which, in contrast with traditional models, there are no underlying psychoeconomic scales. Instead, we assume that an attribute’s subjective value is constructed from a series of binary, ordinal comparisons to a sample of attribute values drawn from memory and is its rank within the sample. We assume that the sample reflects both the immediate distribution of attribute values from the current decision’s context and also the background, real-world distribution of attribute values. DbS accounts for concave utility functions; losses looming larger than gains; hyperbolic temporal discounting; and the overestimation of small probabilities and the underestimation of large probabilities
Harnessing high altitude solar power
No full textAs an intermediate solution between Glaser's satellite solar power (SSP) and ground-based photovoltaic (PV) panels, this paper examines the collection of solar energy using a high-altitude aerostatic platform. A procedure to calculate the irradiance in the medium/high troposphere, based on experimental data, is described. The results show that here a PV system could collect about four to six times the energy collected by a typical U.K.-based ground installation, and between one-third and half of the total energy the same system would collect if supported by a geostationary satellite (SSP). The concept of the aerostat for solar power generation is then briefly described together with the equations that link its main engineering parameters/variables. A preliminary sizing of a facility stationed at 6 km altitude and its costing, based on realistic values of the input engineering parameters, is then presented
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