Second-Order Belief Hidden Markov Models

Hidden Markov Models (HMMs) are learning methods for pattern recognition. The probabilistic HMMs have been one of the most used techniques based on the Bayesian model. First-order probabilistic HMMs were adapted to the theory of belief functions such that Bayesian probabilities were replaced with mass functions. In this paper, we present a second-order Hidden Markov Model using belief functions. Previous works in belief HMMs have been focused on the first-order HMMs. We extend them to the second-order model

Designing a Belief Function-Based Accessibility Indicator to Improve Web Browsing for Disabled People

The purpose of this study is to provide an accessibility measure of web-pages, in order to draw disabled users to the pages that have been designed to be ac-cessible to them. Our approach is based on the theory of belief functions, using data which are supplied by reports produced by automatic web content assessors that test the validity of criteria defined by the WCAG 2.0 guidelines proposed by the World Wide Web Consortium (W3C) organization. These tools detect errors with gradual degrees of certainty and their results do not always converge. For these reasons, to fuse information coming from the reports, we choose to use an information fusion framework which can take into account the uncertainty and imprecision of infor-mation as well as divergences between sources. Our accessibility indicator covers four categories of deficiencies. To validate the theoretical approach in this context, we propose an evaluation completed on a corpus of 100 most visited French news websites, and 2 evaluation tools. The results obtained illustrate the interest of our accessibility indicator

Evidential-EM Algorithm Applied to Progressively Censored Observations

Evidential-EM (E2M) algorithm is an effective approach for computing maximum likelihood estimations under finite mixture models, especially when there is uncertain information about data. In this paper we present an extension of the E2M method in a particular case of incom-plete data, where the loss of information is due to both mixture models and censored observations. The prior uncertain information is expressed by belief functions, while the pseudo-likelihood function is derived based on imprecise observations and prior knowledge. Then E2M method is evoked to maximize the generalized likelihood function to obtain the optimal estimation of parameters. Numerical examples show that the proposed method could effectively integrate the uncertain prior infor-mation with the current imprecise knowledge conveyed by the observed data

Belief Hierarchical Clustering

In the data mining field many clustering methods have been proposed, yet standard versions do not take into account uncertain databases. This paper deals with a new approach to cluster uncertain data by using a hierarchical clustering defined within the belief function framework. The main objective of the belief hierarchical clustering is to allow an object to belong to one or several clusters. To each belonging, a degree of belief is associated, and clusters are combined based on the pignistic properties. Experiments with real uncertain data show that our proposed method can be considered as a propitious tool

Trading risks: The value of relationships, models and face-to-face interaction in the global reinsurance market

Over the past 20 years, the reinsurance industry has experienced three profound forces for change. First, technological change has improved information distribution and strengthened connections between global markets. Second, regulatory emphasis on global equivalence in trading practices has generated pressure for convergence across different marketplaces. Third, the widespread acceptance of vendor property catastrophe models has led to more standardised approaches to the evaluation of reinsurance risks, levelling the playing field for decision-making on at least some classes of business. These changes have intensified competition between reinsurance markets. Reinsurance trading centres in remote geographic locations, such as Bermuda, where it is more difficult to transact business face-to-face, have been able to write risk via electronic communications and now have very significant positions in the global reinsurance market. Simultaneously, Lloyd’s of London, one of the original reinsurance markets that is still very much based on the face-to-face approach, has demonstrated its capability to weather financial shocks and downturns and remains an important player in global reinsurance

Post-grooming furunculose bij een hond

A five-year-old, intact, male labrador retriever was presented on emergency with general complaints of fever, lethargy and anorexia. During clinical examination, very painful skin lesions were noticed dorsally on the neck and back, and there was also a clear left apical systolic murmur with a degree of 4/6. On histopathological examination of the lesional skin, there was rupture of the follicle wall surrounded with a pronounced suppurative inflammation. The dog was diagnosed with post-grooming furunculosis and mitral valve endocardiosis ACVIM stage B2. Culture of the lesional skin and the shampoo used to wash the dog prior to the onset of the skin lesions revealed the presence of the same bacteria, evidencing a clear link between the bathing and development of the skin lesions

Charting new territory for organizational ethnography : Insights from a team-based video ethnography

Purpose: Increasing complexity, fragmentation, mobility, pace, and technological intermediation of organizational life make “being there” increasingly difficult. Where do ethnographers have to be, when, for how long, and with whom to “be there” and grasp the practices, norms, and values that make the situation meaningful to natives? These novel complexities call for new forms of organizational ethnography. The purpose of this paper is to discuss the above issues. Design/methodology/approach: In this paper, the authors respond to these calls for innovative ethnographic methods in two ways. First, the paper reports on the practices and ethnographic experiences of conducting a year-long team-based video ethnography of reinsurance trading in London. Findings: Second, drawing on these experiences, the paper proposes a framework for systematizing new approaches to organizational ethnography and visualizing the ways in which they are “expanding” ethnography as it was traditionally practiced. Originality/value: The paper contributes to the ethnographic literature in three ways: first, the paper develops a framework for charting new approaches to ethnography and highlight its different dimensions – site, instrument, and fieldworker. Second, the paper outlines the opportunities and challenges associated with these expansions, specifically with regard to research design, analytical rigour, and communication of results. Third, drawing on the previous two contributions, the paper highlights configurations of methodological expansions on the aforementioned dimensions that are more promising than others in leveraging new technologies and approaches to claim new territory for organizational ethnography and enhance its relevance for understanding today's multifarious organizational realities

Limited sampling strategies to estimate glomerular filtration rate in cats with low, normal and high glomerular filtration rates

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