Search results for "Relational"
showing 10 items of 238 documents
A relational model for unstructured documents
1987
The logical structure of a document is usually a tree in which the order of the nodes is important at least at some level of the tree. We call a document unstructured if its structure is a single-level ordered tree. The purpose of this paper is to present a many-sorted algebra for handling unstructured documents. The documents in the model are represented by relations. An algebra for handling documents of one type can be extended to an algebra for handling documents of several types. Further, an algebra for handling documents can be extended by the relational algebra for handling documents and relations in a common algebra. The model of this paper can be regarded as a part of a general docu…
Induced and reduced unbounded operator algebras
2012
The induction and reduction precesses of an O*-vector space \({{\mathfrak M}}\) obtained by means of a projection taken, respectively, in \({{\mathfrak M}}\) itself or in its weak bounded commutant \({{\mathfrak M}^\prime_{\rm w}}\) are studied. In the case where \({{\mathfrak M}}\) is a partial GW*-algebra, sufficient conditions are given for the induced and the reduced spaces to be partial GW*-algebras again.
Automatic Reengineering in MDA Using Rewriting Logic as Transformation Engine
2005
Legacy systems are information systems that have been developed by means of methods, tools and database management systems that have become obsolete, but they are still being used due to their reliability. As time goes on, the maintenance of this software becomes more complex, expensive and painful. The MOMENT framework supports automatic formal model transformations in MDA. This model transformation approach is based on the algebraic specification of models and benefits from mature term rewriting system technology to perform model transformation using rewriting logic. In this paper, we present how we apply this formal transformation mechanism to recover a legacy relational database, obtain…
Una lettura urbana su Balestrate. Realtà intermedia e nuove possibili centralità
2014
This work was developed at the “R-Lab” project, a workshop that was experimentally promoted by the University of Palermo (teachers, students and researchers) during the academic years 2010-11 and 2011-12. Workshop participants collected and elaborated analysis and proposals in an interdisciplinary and multi-level way (PhD, degree thesis, co-financed research) with lessons, seminars and applied research. Prof. F. Maggio coordinated the section that was titled “Analysis of the smaller towns in Sicily”, and we worked with him within an agreement that was signed with the local administration of Balestrate, a small coastal town in the northwestern Sicily. Our work focuses on some issues of the t…
Privacy Violation Classification of Snort Ruleset
2010
Published version of a paper presented at the 2010 18th Euromicro International Conference on Parallel, Distributed and Network-Based Processing (PDP). (c) 2010 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works. Paper also available from the publisher:http://dx.doi.org/10.1109/PDP.2010.87 It is important to analyse the privacy impact of Intrusion Detection System (IDS) rules, in order to understand a…
“Practicing care in qualitative organizational research: moral responsibility and legitimacy in a study of immigration management”
2021
PurposeThe purpose of this paper is to provide insight into the reciprocal relations between the caregiving imparted by immigration centre managers and the role of the researcher in responding to the care that is given by managerial caregivers. To enable this, we draw on a feminist theory of care ethics that considers individuals as relationally interdependent.Design/methodology/approachThe analysis draws on a semi-structured interview study involving 20 Finnish immigration reception centre managers.FindingsInsight is generated by reflecting on moments of care that arise between research participants and the researcher in a study of immigration centre management. We emphasise the importance…
Towards an efficient epsilon near-zero-based wavefront shaper
2017
Although epsilon-near-zero (ENZ) metamaterials offer many unconventional ways to play with light, the optical impedance mismatch with surroundings can limit the efficiency of future devices. An original example of ENZ-based applications is the wavefront shaping, but up to now devices have transmission efficiency as low as 10-5 [1]. Here, we report strategies to enhance the transmittance through ENZ layer and we demonstrate an enhancement by four orders of magnitude of the transmittance, which reaches up to 15% in the context of ENZ-based wavefront shaping [2].
Improving the transmittance of an epsilon-near-zero-based wavefront shaper
2016
Although Epsilon-Near-Zero metamaterials (ENZ) offer many unconventional ways to play with light, the optical impedance mismatch with surroundings can limit the efficiency of future devices. We report here on the improvement of the transmittance of an Epsilon-Near-Zero (ENZ) wavefront shaper. We first address in this paper the way to enhance the transmittance of a plane wave through a layer of ENZ material thanks to a numerical optimization approach based on the Transfer Matrix Method. We then transpose the one dimensional approach to a two dimensional case where the emission of a dipole is shaped into a plane wave by an ENZ device with a design that optimizes the transmittance. As a result…
Query-preserving watermarking of relational databases and XML documents
2011
Watermarking allows robust and unobtrusive insertion of information in a digital document. During the last few years, techniques have been proposed for watermarking relational databases or Xml documents, where information insertion must preserve a specific measure on data (for example the mean and variance of numerical attributes). In this article we investigate the problem of watermarking databases or Xml while preserving a set of parametric queries in a specified language, up to an acceptable distortion. We first show that unrestricted databases can not be watermarked while preserving trivial parametric queries. We then exhibit query languages and classes of structures that allow guarante…
Modèle tensoriel pour l'entreposage et l'analyse des données des réseaux sociaux Application à l'étude de la viralité sur Twitter
2018
International audience; Dans cet article, nous montrons comment la notion de tenseur permet de construire un modèle multi-paradigmes pour l'entreposage des données sociales. D'un point de vue architecture , cette approche permet de lier différents systèmes de stockage (polystore) et de limiter l'impact des outils ETL réalisant les transformations de modèles pour alimenter différents al-gorithmes d'analyse. Ainsi, le modèle proposé permet d'assurer l'indépendance logique entre les données et les programmes implantant les algorithmes d'analyse. Avec un cas concret ex-trait d'une étude de la viralité sur Twitter durant la période de l'entre deux tours de l'élection présidentielle française de …