Information retrieval with FROM: The fuzzy relational ontological model

This paper presents FROM, the fuzzy relational ontological model, a novel approach to encode knowledge for information retrieval applications based upon a fuzzy set framework that consider more generic concepts differently from specific terms. Besides the model itself, the paper also presents a retrieval algorithm that exploits FROM features through the application of fuzzy operations that uses this knowledge to extend a user's query based on these fuzzy associations. Experimental results have shown that retrieval with FROM presented better overall performance than other fuzzy‐based approaches for information retrieval. © 2009 Wiley Periodicals, Inc.     

Neuro-evolutionary mobile robot egomotion estimation with a 3D ToF camera

An innovative neuro-evolutionary approach for mobile robot egomotion estimation with a 3D ToF camera is proposed. The system is composed of two main modules following a preprocessing step. The first module is a Neural Gas network that computes a Vector Quantization of the preprocessed camera 3D point cloud. The second module is an Evolution Strategy that estimates the robot motion parameters by performing a registration process, searching on the space of linear transformations, restricted to the translation and rotation, between the codebooks obtained for successive camera readings. The fitness function is the matching error between the predicted and the observed codebook corresponding to the next camera readings. In this paper, we report results of an implementation of this system tested on data from a real mobile robot, and provide several comparisons between our and other well-known registration algorithms.     

Relation between electrical and mechanical properties of conducting polymer composites

The influence of the carbon black content on the mechanical and electrical properties of polypropylene/carbon black composites prepared by different processing procedures was investigated. The formation of a continuous conducting network in the insulating matrix and, consequently, the percolation threshold depend strongly on the processing route and influence both the mechanical and electrical properties of the prepared composites. An interesting coincidence of the dependencies of conductivity and elongation at break on the filler content was found. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1903–1906, 2001     

Anticoagulant, Antioxidant and Antitumor Activities of Heterofucans from the Seaweed Dictyopteris delicatula

In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (～45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress.     

Surprise, memory, and retrospective judgment making: Testing cognitive reconstruction theories of the hindsight bias effect.

Hindsight bias has been shown to be a pervasive and potentially harmful decision-making bias. A review of 4 competing cognitive reconstruction theories of hindsight bias revealed conflicting predictions about the role and effect of expectation or surprise in retrospective judgment formation. Two experiments tested these predictions examining the effects of manipulating the information presented in a text-based scenario and its congruency with the given outcome on surprise, hindsight bias, and recall. The results of Experiment 1 revealed evidence of hindsight bias after exposure to incongruent and ambivalent outcomes but not after exposure to congruent outcomes. Experiment 2 replicated the hindsight bias results and found that the ratio of outcome consistent information recalled was higher than expected in the incongruent and ambivalent conditions but equaled the ratio presented to participants in the congruent condition. The results were interpreted as supporting the general predictions of sense-making models of the hindsight bias. A refined version of this model is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microstructural study of aged ferrite powders for sensing layers

Nanosized powders of La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w were investigated in terms of structural, morphological, chemical and surface properties by using several characterization techniques. The XPS and IR measurements showed the presence of surface hydroxide and carbonates species. After calcination of the powders at 900 °C the amount of carbonates decreased but was still significant. The sensing activity of thick film based on La_0.80Sr_0.20Fe_0.95Cu_0.05O_3?w was tested as a function of relative humidity and the results indicate that (i) after one year of ambient storage the sensing material lost quite completely its sensitivity to humidity, (ii) the sensing activity of the film was mostly re-activated after a thermal treatment at 900 °C for 2 h, and (iii) the huge shift of the detection limit to low RH caused by the presence of 5 mol% Cu is also restored.     

A non-associative generalization of effect algebras

Effect algebras play an important role in the logic of quantum mechanics. The aim of this paper is to drop the associativity of addition. However, some important properties of effect algebras are preserved, e.g. every so-called skew effect algebra is still a bounded poset with an antitone involution. Moreover, skew effect algebras are fully characterized as certain bounded posets with sectionally switching involutions.     

Micro- and macroscopic thermal expansion of stabilized aluminum titanate

The lattice expansion of aluminum titanate (AT) obtained by firing a mixture of alumina, rutile, strontium and calcium carbonate and silica was measured using neutron and laboratory X-ray diffraction. The microscopic data are compared with macroscopic measurement completed by dilatometry.A powder and a compact rod sample were compared to assess the influence of micro residual stresses locked into the solid structure at grain level, which could possibly be relieved upon grinding.Results show good correlation between neutron and X-ray diffraction techniques. They also show that a compact material behaves differently than a powder, contrary to what happens for other porous ceramics such as cordierite. The integrity factor model was used to rationalize the results and predict grain level stresses in all crystal directions and all phases (AT, Strontium aluminum silicate, alumina and residual glass). Calculation show that the AT c-axis is always under compression while all other crystal directions and phases are under tension. Those micro-stresses do not undermine the macroscopic mechanical properties of the material and confer to it its interesting properties like low thermal expansion and enhanced strain tolerance.