Reverse Pivoting in Conceptual Information Systems

In database marketing, the behavior of customers is analyzed by studying the transactions they have performed. In order to get a global picture of the behavior of a customer, his single transactions have to be composed together. In On-Line Analytical Processing, this operation is known as reverse pivoting. With the ongoing data analysis process, reverse pivoting has to be repeated several times, usually requiring an implementation in SQL. In this paper, we present a construction for conceptual scales for reverse pivoting in Conceptual Information Systems, and also discuss the visualization. The construction allows the reuse of previously created queries without reprogramming and o#ers a visualization of the results by line diagrams

RCA as a Data Transforming Method: A Comparison with Propositionalisation

International audienceThis paper aims at comparing transformation-based appro-aches built to deal with relational data, and in particular two approaches which have emerged in two different communities: Relational Concept Analysis (RCA), based on an iterative use of the classical Formal Con-cept Analysis (FCA) approach, and Propositionalisation coming from the Inductive Logic Programming community. Both approaches work by transforming a complex problem into a simpler one, namely transform-ing a database consisting of several tables into a single table. For this purpose, a main table is chosen and new attributes capturing the in-formation from the other tables are built and added to this table. We show the similarities between those transformations for what concerns the principles underlying them, the semantics of the built attributes and the result of a classification performed by FCA on the enriched table. This is illustrated on a simple dataset and we also present a synthetic comparison based on a larger dataset from the hydrological domain

Intelligent structuring and reducing of association rules with formal concept analysis

Colloque avec actes et comité de lecture. internationale.International audienceAssociation rules are used to investigate large databases. The analyst is usually confronted with large lists of such rules and has to find the most relevant ones for his purpose. Based on results about knowledge representation within the theoretical framework of Formal Concept Analysis, we present relatively small bases for association rules from which all rules can be deduced. We also provide algorithms for their calculation

Ocular complications in survivors of the Ebola outbreak in Guinea

PURPOSE: The Ebola outbreak of 2013-2016 severely affected West Africa and resulted in 2544 deaths and 1270 survivors in Guinea, the country where it began. This Ebola virus was the Zaire strain of the virus family Filoviridae. In this outbreak the case fatality rate was about 67%. The survivors, declared cured after 2 negative blood polymerase chain reaction (PCR) results, face psychosocial disorders and rheumatic, ear-nose-throat, neurocognitive, and ophthalmologic complications. The goal of this study was to detect and describe ocular complications afflicting these survivors and to observe their occurrence and recurrences. DESIGN: Prospective observational cohort study. METHODS: This prospective observational multicenter cohort study was initiated in March 2015. The cohort study included 341 survivors followed up in the infectious disease ward of Conakry, Forecariah, and Nzerekore as of May 2016. The patients received multidisciplinary medical follow-up expected to last at least 1 year that included an eye examination as part of complete, free treatment. RESULTS: Systematic examination of 341 patients revealed 46 cases of uveitis (13.5%), 6 cases of episcleritis (1.8%), and 3 cases of interstitial keratitis (0.9%). Uveitis was most frequently unilateral (78.3%) and anterior (47.8%) and occurred within the 2 months after discharge from the Ebola treatment center. Moreover, uveitis relapses were found up to 13 months after the negative PCR result for Ebola in the blood. CONCLUSION; Nearly 1 out of 6 survivors presented ocular disorders after discharge from the Ebola treatment center. An ophthalmologic follow-up for Ebola-infected patients should start, if possible, during the acute phase of the disease and last more than 1 year. Treatment guidelines need to be urgently developed and implemented

An FCA interpretation of Relation Algebra

This paper discusses an interpretation of relation algebra and fork algebra with respect to FCA contexts. In this case, "relation algebra" refers to the DeMorgan-Peirce-Schroeder-Tarski algebra and not to the "relational algebra" as described by Codd. The goal of this interpretation is to provide an algebraic formalisation of object-relational databases that is based on binary relations and thus closer to FCA and formal contexts than the traditional formalisation based on Codd. The formalisation provides insights into certain symmetries (among quantifiers) and the use of ternary relations and part-whole relations for building relational databases

An application of relation algebra to lexical databases

This paper presents an application of relation algebra to lexical databases. The semantics of knowledge representation formalisms and query languages can be provided either via a set-theoretic semantics or via an algebraic structure. With respect to formalisms based on n-ary relations (such as relational databases or power context families), a variety of algebras is applicable. In standard relational databases and in formal concept analysis (FCA) research, the algebra of choice is usually some form of Cylindric Set Algebra (CSA) or Peircean Algebraic Logic (PAL). A completely different choice of algebra is a binary Relation Algebra (RA). In this paper, it is shown how RA can be used for modelling FCA applications with respect to lexical databases