Papers by Eduardo Ramirez
In this chapter we discuss the general aspects related to the utilization of MultiAgent systems i... more In this chapter we discuss the general aspects related to the utilization of MultiAgent systems in Enterprise environments with special emphasis on the integration architectures enabled by Web Service technologies. Also, we present a decoupled architectural approach that ...
2008 Seventh Mexican International Conference on Artificial Intelligence, 2008
Wikipedia is nowadays one of the most valuable infor-mation resources; nevertheless, its current ... more Wikipedia is nowadays one of the most valuable infor-mation resources; nevertheless, its current structure, which has no formal organization, does not allow to always have a useful browsing among topics. Moreover, even though most Wikipedia pages include a See Also section ...
Neurocomputing, 2012
In this paper the problem of performing external validation of the semantic coherence of topic mo... more In this paper the problem of performing external validation of the semantic coherence of topic models is considered. The Fowlkes-Mallows index, a known clustering validation metric, is generalized for the case of overlapping partitions and multi-labeled collections, thus making it suitable for validating topic modeling algorithms. In addition, we propose new probabilistic metrics inspired by the concepts of recall and precision. The proposed metrics also have clear probabilistic interpretations and can be applied to validate and compare other soft and overlapping clustering algorithms. The approach is exemplified by using the Reuters-21578 multi-labeled collection to validate LDA models, then using Monte Carlo simulations to show the convergence to the correct results. Additional statistical evidence is provided to better understand the relation of the metrics presented.
Journal of the Chilean Chemical Society, 2003
Crystal and molecular structure and the thermal properties of (N,N-dibencyl)-4-nitrophenylsulfena... more Crystal and molecular structure and the thermal properties of (N,N-dibencyl)-4-nitrophenylsulfenamide , (C 6 H 5 CH 2 ) 2 NSC 6 H 4 -4-NO 2 , is herein presented. The structure is a divalent sulfur compound that crystallized in the monoclinic system, space group P2 1 /c with ...
Boletín de la Sociedad Chilena de Química, 2002
The crystal and molecular structure of 5-nitropiridine piperidine-sulfenamide, C 10 H 13 N 3 O 2 ... more The crystal and molecular structure of 5-nitropiridine piperidine-sulfenamide, C 10 H 13 N 3 O 2 S is described and compared with other sulfenamides and with other similar compounds. This structure belongs to a type of divalent sulphur compound and crystallizes in the ...
Electrochimica Acta, 2010
We study the thermodynamics and kinetics of the adsorption of a redox couple having quinone natur... more We study the thermodynamics and kinetics of the adsorption of a redox couple having quinone nature on glassy carbon electrodes. This couple is produced by the anodic oxidation of mycotoxin ochratoxin A in 10% acetonitrile + 90% 1 M HClO 4 aqueous solution. The quasi-reversible redox couple was studied by both cyclic (CV) and square wave (SWV) voltammetric techniques. The Frumkin adsorption isotherm best described the specific interaction of the redox couple with carbon electrodes. By fitting the experimental data, we obtained values of −28.4 kJ mol −1 and 0.70 ± 0.02 for the Gibbs free energy of adsorption and the interaction parameter, respectively. SWV fully characterized the thermodynamics and kinetics of the adsorbed redox couple, using a combination of the "quasi-reversible maximum" and the "splitting of SW peaks" methods. Average values of 0.609 ± 0.003 V and 0.45 ± 0.06 were obtained for the formal potential and the anodic transfer coefficient, respectively. Moreover, a formal rate constant of 10.7 s −1 was obtained. SWV was also employed to generate calibration curves. The lowest concentration of mycotoxin was 1.24 × 10 −8 M (5 ppb), measured indirectly with a signal to noise ratio of 3:1.
Bioelectromagnetics, 1983
Drosophila flies placed in a habitat with two lateral boxes demonstrated sensitivity to magnetic ... more Drosophila flies placed in a habitat with two lateral boxes demonstrated sensitivity to magnetic fields: Oviposition decreased by exposure to pulsated (extremely low frequency (ELF) (lo0 Hz, 1.76 miliTesla (mT)) and sinusosidal fields (50 Hz, 1 mT), while there was no initial effect of exposure to a static magnetic field (4.5 mT). Drosophila eggs treated for 48 h with the above described fields showed that 1) mortality of eggs was lower in controls than in eggs exposed to all tested magnetic fields; 2 ) mortality of larvue increased when a permanent magnet was used; 3) mortality of pupae was highest when a permanent magnet was used; and 4) general adult viability was highest in controls (679) and diminished progressively when eggs were exposed to pulsated (55%), sinusoidal (45%), and static (35%) magnetic fields.
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Papers by Eduardo Ramirez