25 resultados para Information content

em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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We present an information-theoretic method to measure the structural information content of networks and apply it to chemical graphs. As a result, we find that our entropy measure is more general than classical information indices known in mathematical and computational chemistry. Further, we demonstrate that our measure reflects the essence of molecular branching meaningfully by determining the structural information content of some chemical graphs numerically.

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In this paper we define the structural information content of graphs as their corresponding graph entropy. This definition is based on local vertex functionals obtained by calculating-spheres via the algorithm of Dijkstra. We prove that the graph entropy and, hence, the local vertex functionals can be computed with polynomial time complexity enabling the application of our measure for large graphs. In this paper we present numerical results for the graph entropy of chemical graphs and discuss resulting properties. (C) 2007 Elsevier Ltd. All rights reserved.

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We extend the concept that life is an informational phenomenon, at every level of organisation, from molecules to the global ecological system. According to this thesis: (a) living is information processing, in which memory is maintained by both molecular states and ecological states as well as the more obvious nucleic acid coding; (b) this information processing has one overall function-to perpetuate itself; and (c) the processing method is filtration (cognition) of, and synthesis of, information at lower levels to appear at higher levels in complex systems (emergence). We show how information patterns, are united by the creation of mutual context, generating persistent consequences, to result in 'functional information'. This constructive process forms arbitrarily large complexes of information, the combined effects of which include the functions of life. Molecules and simple organisms have already been measured in terms of functional information content; we show how quantification may be extended to each level of organisation up to the ecological. In terms of a computer analogy, life is both the data and the program and its biochemical structure is the way the information is embodied. This idea supports the seamless integration of life at all scales with the physical universe. The innovation reported here is essentially to integrate these ideas, basing information on the 'general definition' of information, rather than simply the statistics of information, thereby explaining how functional information operates throughout life. © 2013 Springer Science+Business Media Dordrecht.

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We propose and advocate basic principles for the fusion of incomplete or uncertain information items, that should apply regardless of the formalism adopted for representing pieces of information coming from several sources. This formalism can be based on sets, logic, partial orders, possibility theory, belief functions or imprecise probabilities. We propose a general notion of information item representing incomplete or uncertain information about the values of an entity of interest. It is supposed to rank such values in terms of relative plausibility, and explicitly point out impossible values. Basic issues affecting the results of the fusion process, such as relative information content and consistency of information items, as well as their mutual consistency, are discussed. For each representation setting, we present fusion rules that obey our principles, and compare them to postulates specific to the representation proposed in the past. In the crudest (Boolean) representation setting (using a set of possible values), we show that the understanding of the set in terms of most plausible values, or in terms of non-impossible ones matters for choosing a relevant fusion rule. Especially, in the latter case our principles justify the method of maximal consistent subsets, while the former is related to the fusion of logical bases. Then we consider several formal settings for incomplete or uncertain information items, where our postulates are instantiated: plausibility orderings, qualitative and quantitative possibility distributions, belief functions and convex sets of probabilities. The aim of this paper is to provide a unified picture of fusion rules across various uncertainty representation settings.

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The grading of crushed aggregate is carried out usually by sieving. We describe a new image-based approach to the automatic grading of such materials. The operational problem addressed is where the camera is located directly over a conveyor belt. Our approach characterizes the information content of each image, taking into account relative variation in the pixel data, and resolution scale. In feature space, we find very good class separation using a multidimensional linear classifier. The innovation in this work includes (i) introducing an effective image-based approach into this application area, and (ii) our supervised classification using wavelet entropy-based features.

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There is a gulf between the enormous information content of the various genome projects and the understanding of the life of the parasite in the host. In vitro studies with adult Schistosoma mansoni using several substrates suggest that the excretory system contains both P-glycoproteins and multiresistance proteins. If both these families of protein were active in vivo, they could regulate parasite metabolism and be responsible for the excretion of drugs. During skin penetration, membrane-impermeant molecules of a wide range of molecular weights can be taken into the cercaria and schistosomulum through the nephridiopore, through the surface membrane or through both. We speculate that this uptake process might stimulate novel signalling pathways involved in growth and development.

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Biodiversity is not a commodity, nor a service (ecosystem or otherwise), it is a scientific measure of the complexity of a biological system. Rather than directly valuing biodiversity, economists have tended to value its services, more often the services of 'key' species. This is understandable given the confusion of definitions and measures of biodiversity, but weakly justified if biodiversity is not substitutable. We provide a quantitative and comprehensive definition of biodiversity and propose a framework for examining its substitutability as the first step towards valuation. We define biodiversity as a measure of semiotic information. It is equated with biocomplexity and measured by Algorithmic Information Content (AIC). We argue that the potentially valuable component of this is functional information content (FIC) which determines biological fitness and supports ecosystem services. Inspired by recent extensions to the Noah's Ark problem, we show how FIC/AIC can be calculated to measure the degree of substitutability within an ecological community. From this, we derive a way to rank whole communities by Indirect Use Value, through quantifying the relation between system complexity and production rate of ecosystem services. Understanding biodiversity as information evidently serves as a practical interface between economics and ecological science.

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A benefit function transfer obtains estimates of willingness-to-pay (WTP) for the evaluation of a given policy at a site by combining existing information from different study sites. This has the advantage that more efficient estimates are obtained, but it relies on the assumption that the heterogeneity between sites is appropriately captured in the benefit transfer model. A more expensive alternative to estimate WTP is to analyze only data from the policy site in question while ignoring information from other sites. We make use of the fact that these two choices can be viewed as a model selection problem and extend the set of models to allow for the hypothesis that the benefit function is only applicable to a subset of sites. We show how Bayesian model averaging (BMA) techniques can be used to optimally combine information from all models. The Bayesian algorithm searches for the set of sites that can form the basis for estimating a benefit function and reveals whether such information can be transferred to new sites for which only a small data set is available. We illustrate the method with a sample of 42 forests from U.K. and Ireland. We find that BMA benefit function transfer produces reliable estimates and can increase about 8 times the information content of a small sample when the forest is 'poolable'. © 2008 Elsevier Inc. All rights reserved.

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Biodiversity may be seen as a scientific measure of the complexity of a biological system, implying an information basis. Complexity cannot be directly valued, so economists have tried to define the services it provides, though often just valuing the services of 'key' species. Here we provide a new definition of biodiversity as a measure of functional information, arguing that complexity embodies meaningful information as Gregory Bateson defined it. We argue that functional information content (FIC) is the potentially valuable component of total (algorithmic) information content (AIC), as it alone determines biological fitness and supports ecosystem services. Inspired by recent extensions to the Noah's Ark problem, we show how FIC/AIC can be calculated to measure the degree of substitutability within an ecological community. Establishing substitutability is an essential foundation for valuation. From it, we derive a way to rank whole communities by Indirect Use Value, through quantifying the relation between system complexity and the production rate of ecosystem services. Understanding biodiversity as information evidently serves as a practical interface between economics and ecological science. © 2012 Elsevier B.V.

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We report the characterization of a new eight-allele microsatellite (D3S621) isolated from a human chromosome 3 library. Two-point and multi-locus genetic linkage analysis have shown D3S621 to co-segregate with the previously mapped RP4 (theta m = 0.12, Zm = 4.34) and with other genetic markers on the long arm of the chromosome, including D3S14 (R208) (theta m = 0.00, Zm = 15.10), D3S47 (C17) (theta m = 0.11, Zm = 4.95), Rho (theta m = 0.07, Zm = 1.37), D3S21 (L182) (theta m = 0.07, Zm = 2.40) and D3S19 (U1) (theta m = 0.13, Zm = 2.78). This highly informative marker, with a polymorphic information content of 0.78, should be of considerable value in the extension of linkage data for autosomal dominant retinitis pigmentosa with respect to locii on the long arm of chromosome 3.

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Background: This study investigated the nature of newspaper reporting about online health information in the UK and US. Internet users frequently search for health information online, although the accuracy of the information retrieved varies greatly and can be misleading. Newspapers have the potential to influence public health behaviours, but information has been lacking in relation to how newspapers portray online health information to their readers.

Methods: The newspaper database Nexis (R) UK was searched for articles published from 2003 - 2012 relating to online health information. Systematic content analysis of articles published in the highest circulation newspapers in the UK and US was performed. A second researcher coded a 10% sample to establish inter-rater reliability of coding.

Results: In total, 161 newspaper articles were included in the analysis. Publication was most frequent in 2003, 2008 and 2009, which coincided with global threats to public health. UK broadsheet newspapers were significantly more likely to cover online health information than UK tabloid newspapers (p = 0.04) and only one article was identified in US tabloid newspapers. Articles most frequently appeared in health sections. Among the 79 articles that linked online health information to specific diseases or health topics, diabetes was the most frequently mentioned disease, cancer the commonest group of diseases and sexual health the most frequent health topic. Articles portrayed benefits of obtaining online health information more frequently than risks. Quotations from health professionals portrayed mixed opinions regarding public access to online health information. 108 (67.1%) articles directed readers to specific health-related web sites. 135 (83.9%) articles were rated as having balanced judgement and 76 (47.2%) were judged as having excellent quality reporting. No difference was found in the quality of reporting between UK and US articles.

Conclusions: Newspaper coverage of online health information was low during the 10-year period 2003 to 2012. Journalists tended to emphasise the benefits and understate the risks of online health information and the quality of reporting varied considerably. Newspapers directed readers to sources of online health information during global epidemics although, as most articles appeared in the health sections of broadsheet newspapers, coverage was limited to a relatively small readership.

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The potential adverse effects on health of diet-derived advanced glycation end-products (AGEs) is of current interest, due to their proposed involvement in the disease progression of diabetic and uraemic conditions. However, accurate information about levels of AGEs in foods is lacking. The objective of this investigation was to determine the level of one particular AGE, N-epsilon-(carboxymethyl)lysine (CML), a marker of AGE formation, in a wide range of foods commonly consumed in a Western style diet. Individual foods (n = 257) were mixed, lyophilised, ground, reduced, fat-extracted, hydrolysed, and underwent solid-phase extraction. Extracts were analysed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Cereal (2.6 mg/100 g food) and fruit and vegetable (0.13 mg/100 g food) categories had the highest and lowest mean level of CML, respectively, when expressed in mg/100 g food. These data can be used for estimating potential consumer intakes, and provide information that can be used to educated consumers on how to reduce their CML intake. (C) 2011 Elsevier Ltd. All rights reserved.

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A rapidly increasing number of Web databases are now become accessible via
their HTML form-based query interfaces. Query result pages are dynamically generated
in response to user queries, which encode structured data and are displayed for human
use. Query result pages usually contain other types of information in addition to query
results, e.g., advertisements, navigation bar etc. The problem of extracting structured data
from query result pages is critical for web data integration applications, such as comparison
shopping, meta-search engines etc, and has been intensively studied. A number of approaches
have been proposed. As the structures of Web pages become more and more complex, the
existing approaches start to fail, and most of them do not remove irrelevant contents which
may a®ect the accuracy of data record extraction. We propose an automated approach for
Web data extraction. First, it makes use of visual features and query terms to identify data
sections and extracts data records in these sections. We also represent several content and
visual features of visual blocks in a data section, and use them to ¯lter out noisy blocks.
Second, it measures similarity between data items in di®erent data records based on their
visual and content features, and aligns them into di®erent groups so that the data in the
same group have the same semantics. The results of our experiments with a large set of
Web query result pages in di®erent domains show that our proposed approaches are highly
e®ective.

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This paper describes a data model for content representation of temporal media in an IP based sensor network. The model is formed by introducing the idea of semantic-role from linguistics into the underlying concepts of formal event representation with the aim of developing a common event model. The architecture of a prototype system for a multi camera surveillance system, based on the proposed model is described. The important aspects of the proposed model are its expressiveness, its ability to model content of temporal media, and its suitability for use with a natural language interface. It also provides a platform for temporal information fusion, as well as organizing sensor annotations by help of ontologies.

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This article shows how both employers and the state have influenced macro-level processes and structures concerning the content and transposition of the European Union (EU) Employee Information and Consultation (I&C) Directive. It argues that the processes of regulation occupied by employers reinforce a voluntarism which marginalizes rather than shares decision-making power with workers. The contribution advances the conceptual lens of ‘regulatory space’ by building on Lukes’ multiple faces of power to better understand how employment regulation is determined across transnational, national and enterprise levels. The research proposes an integrated analytical framework on which ‘occupancy’ of regulatory space can be evaluated in comparative national contexts.