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Deep Knowledge (deep + knowledge)

Distribution by Scientific Domains
Chemistry40%

Selected Abstracts

User profiling on the Web based on deep knowledge and sequential questioning

EXPERT SYSTEMS, Issue 1 2006
Silvano Mussi
Abstract: User profiling on the Web is a topic that has attracted a great number of technological approaches and applications. In most user profiling approaches the website learns profiles from data implicitly acquired from user behaviours, i.e. observing the behaviours of users with a statistically significant number of accesses. This paper presents an alternative approach. In this approach the website explicitly acquires data from users, user interests are represented in a Bayesian network, and user profiles are enriched and refined over time. The profile enrichment is achieved through a sequential asking algorithm based on the value-of-information theory using the Shannon entropy concept. However, what mostly characterizes the approach is the fact that the user is involved in a collaborative process of profile building. The approach has been tried out for over a year in a real application. On the basis of the experimental results the approach turns out to be particularly suitable for applications where the website is strongly based on deep domain knowledge (as for example is the case for scientific websites) and has a community of users that share the same domain knowledge of the website and produce a ,low' number of accesses (,low' compared to the high number of accesses of a typical commercial website). After presenting the technical aspects of the approach, we discuss the underlying ideas in the light of the experimental results and the literature on human,computer interaction and user profiling. [source]

A Model-Based Method for an Online Diagnostic Knowledge-Based System

EXPERT SYSTEMS, Issue 3 2001
Chrissanthi Angeli
Fault diagnosis is very important for modern production technology and has received increasing theoretical and practical attention during the last few years. This paper presents a model-based diagnostic method for industrial systems. An online, real-time, deep knowledge based fault detection system has been developed by combining different development environments and tools. The system diagnoses, predicts and compensates faults by coupling symbolic and numerical data in a new environment suitable for the interaction of different sources of knowledge and has been successfully implemented and tested on a real hydraulic system. [source]

Ceramic Supported Capillary Pd Membranes for Hydrogen Separation: Potential and Present Limitations

FUEL CELLS, Issue 6 2006
V. Gepert
Abstract Composite ceramic capillaries coated with thin palladium membranes are developed for the production of CO-free hydrogen for PEM fuel cells, via alcohol steam reforming. The composite membranes are tested for pure H2 and N2, as well as for synthetic reformate gas. The aim is to develop a heat-integrated compact membrane reformer for decentralized hydrogen production. In this context, a deep knowledge of the performance, behavior, and necessary treatment of the composite palladium membranes plays a decisive role in process design. The current contribution focuses on the main hurdles met while attempting to exploit the potential of ceramic supported capillary palladium membranes. [source]

Mode crystallography of distorted structures

ACTA CRYSTALLOGRAPHICA SECTION A, Issue 5 2010
J. M. Perez-Mato
The description of displacive distorted structures in terms of symmetry-adapted modes is reviewed. A specific parameterization of the symmetry-mode decomposition of these pseudosymmetric structures defined on the setting of the experimental space group is proposed. This approach closely follows crystallographic conventions and permits a straightforward transformation between symmetry-mode and conventional descriptions of the structures. Multiple examples are presented showing the insight provided by the symmetry-mode approach. The methodology is shown at work, illustrating its various possibilities for improving the characterization of distorted structures, for example: detection of hidden structural correlations, identification of fundamental and marginal degrees of freedom, reduction of the effective number of atomic positional parameters, quantitative comparison of structures with the same or different space group, detection of false refinement minima, systematic characterization of thermal behavior, rationalization of phase diagrams and various symmetries in families of compounds etc. The close relation of the symmetry-mode description with the superspace formalism applied to commensurate superstructures is also discussed. Finally, the application of this methodology in the field of ab initio or first-principles calculations is outlined. At present, there are several freely available user-friendly computer tools for performing automatic symmetry-mode analyses. The use of these programs does not require a deep knowledge of group theory and can be applied either a posteriori to analyze a given distorted structure or a priori to parameterize the structure to be determined. It is hoped that this article will encourage the use of these tools. All the examples presented here have been worked out using the program AMPLIMODES [Orobengoa et al. (2009). J. Appl. Cryst.42, 820,833]. [source]

New insights into the phylogenetics and biogeography of Arum (Araceae): unravelling its evolutionary history

BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2010
ANAHÍ ESPÍNDOLA
The heat- and odour-producing genus Arum (Araceae) has interested scientists for centuries. This long-term interest has allowed a deep knowledge of some complex processes, such as the physiology and dynamics of its characteristic lure-and-trap pollination system, to be built up. However, mainly because of its large distributional range and high degree of morphological variation, species' limits and relationships are still under discussion. Today, the genus comprises 28 species subdivided into two subgenera, two sections and six subsections. In this study, the phylogeny of the genus is inferred on the basis of four plastid regions, and the evolution of several morphological characters is investigated. Our phylogenetic hypothesis is not in agreement with the current infrageneric classification of the genus and challenges the monophyly of several species. This demonstrates the need for a new infrageneric classification based on characters reflecting the evolution of this enigmatic genus. To investigate the biogeography of Arum deeply, further spatiotemporal analyses were performed, addressing the importance of the Mediterranean basin in the diversification of Arum. Our results suggest that its centre of origin was the European,Aegean region, and that major diversification happened during the last 10 Myr. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 14,32. [source]