Papers, Ph. D Thesis...
1- Mourad Ykhlef, Recursive SQL-like query language for XML, the 9th Internationl conference on Information Integration and Web-based Applications and Services (IIWAS 2007), 3-5 Dec 2007, Jakarta
Abstract: XML data are data which are not constrained by a schema, XML is fast emerging as a standard for data representation and exchange on the Word Wide Web, the ability to intelligently query XML data becomes increasingly important. In this paper we propose a recursive query language XRQL for querying and restructuring XML data. The expressive power of XRQL is comparable to Fixpoint. XRQL language is a multi-sorted SQL-like language integrating grouping, aggregate functions, recursion and nesting.
Keywords: XML, SQL, GROUP BY, Aggregate functions, Recursion, Nested queries.
2- Mourad Ykhlef, A logical foundation for Nested semi-structured data and Web forms, International Journal of Web Information System, Troubador Publisher, Volume 2, Issue 1, pages: 3-17, March 2006 (link)
Abstract: Semi-structured data are commonly represented by labeled flat db-graphs. In this paper, we study an extension of db-graph model for representing nested semi-structured data. This extension allows one to have db-graphs whose vertex labels are db-graphs themselves. Bringing the data model closer to the natural presentation of data stored via Web documents is the main motivation behind nesting db-graphs. The importance of nested db-graphs is similar to the importance of nested tables in relational model. The main purpose of the paper is to provide a mechanism to query nested semi-structured data and Web forms in a uniform way. Most of the languages proposed so far have been designed as extensions of SQL with, among others, the advantage to provide a user-friendly syntax and commercial flavor. The major focus of the
paper is on defining a graph query language in a multi-sorted calculus like style.
keywords: Nested Semi-structured Data, Graph Calculus, Query embedding, Web Forms
3- Mourad Ykhlef, Querying Web Forms and Nested Semi-structured Data, the 7th International Conference on Information Integration and Web-based Applications and services (IIWAS 2005), 19-21 Sept 2005, Malaysia, books@ocg.at of Austrian Computer Scoiety Band 196, V 1, pages: 399-411, ISBN:3-85403-196-3 (pdf)
Abstract: Semi-structured data are commonly represented by labelled graphs.These graphs can be simple or nested.In this paper we present how to model nested semi-structured data in the presence of Web forms.Our motivation is to bring our data model more realistic to capture the richness of Web data. The main purpose of the paper is to provide a mechanism to query nested semi-structured data and web forms in a uniform way.
Keywords: Nested Semi-structured Data, Web Forms, Query embedding, Calculus and Logic
4- Mourad Ykhlef, Querying Semi-structured Data on Internet (in french), Revue d'Information Scientifique et Rechnique, Algeria, year 2003, vol 13 number 01, pages 95-121, ISSN 1111-0015 (link)
Abstarct: Les donees semistructurees ne conforment pas a un schema fixe comme est le cas dans les bases de donnees relationnelles et les bases de donnees orientees objets. La representation et l'interrrogation des donnees semistructurees est plus difficile que dans les donnees structurees, cela est du au fait que les donnees sont heterogenes et le schema est absent, meme si ce dernier est present il ne constitue aucune contrainte sur la base. On presente un panorama de langages pour interroger les donnees semistructurees presentees sous forme de graphes. Les differentes semantiques et la puissance d'expression sont ainsi presentees. Le langage de requetes du type calcul Graph-Fixpoint qu'on a propose dans [BY98,BY99,ykhleft99] est plus puissant que les autres langages existants car il permet d'exprimer des requetes recursives.
Keywords: Internet (Web), donnees semistructurees, db-graphe, requete, puissance d'expression, recursion
5- Nicole Bidoit, Sofian Maabout, Mourad Ykhlef, A family of Nested Query Languages for Semi-structured Data, Foundations of Information and Knowledge Systens, First International Symposium, FoIKS Burg, Germany, 2000, Lecture Notes in Computer Science, Vol 1762, Springer 2000, pages: 13-30, ISBN 3-540-67100-5 (pdf)
Abstract: Semi structured data are commonly represented by labelled graphs The labels may be strings integers... Thus their type is atomic. They are carried by edges and or nodes. In this paper, we investigate a nested graph representation of semi structured data. Some nodes of our graphs may be labelled by graphs. Our motivation is to bring the data model in use closer to the natural presentation of data in particular closer to the Web presentation. The main purpose of the paper is to provide query languages of reasonable expressivepower for querying nested db graphs.
6- Nicole Bidoit, Sofian Maabout, Mourad Ykhlef, A nested langauge for querying and integrating semi-structured data (in french), 15th International Conference in Advanced Databases BDA'1999, Bordeaux, France, pages:63-82 (pdf)
Abstract: Les donnees semistructurees sont generalement modelisees par des graphes etiquetes. Dans ce travail, nous considerons une structure plus generale qui est celle des graphes imbriques. Ceci permet de rendre compte de la nature hierarchique des donnees heterog\`enes. Nous proposons alors un langage de requetes du type calcul imbrique pour interroger des donnees provenant de plusieurs sources et pour les integrer via le Web.
7- Nicole Nidoit, Mourad Ykhlef, Fixpoint Calculus For Querying Semi-Structured Data, Lecture Notes in Computer Science, Vol 1590, Springer, 1999, pages:78-97, ISBN 3-540-65890-4 (link)
Abstract: The paper proposes two query languages for semistructured data G-Fixpoint and G-While whose expressive power is comparable to Fixpoint and While respectively. These languages are multi-sorted like logic languages integrating fixpoint path expressions.
8- Nicole Bidoit, Mourad Ykhlef, Fixpoint Path Queries, International Workshop on the Web and Databases WebDB'1998, in conjunction with EDBT Valencia, Spain, March 1998, pages 56-62 (pdf)
Abstract: The paper proposes two fixpoint path query languages Path-Fixpoint and Path-While for unstructured data whose expressive power is that of Fixpoint and While queries respectively. These languages are multi-sorted like logic languages integrating fixpoint path expressions.
9- Rachid Belamri, Kholladi, Mourad Ykhled, Mourad Zeghib, Urban Spatial Analysis for Digital Cartography, International Conference on Signal And Image Processing, Algiers, Algeria Oct 1994 (pdf)
Abstract: Digital cartography has been an active field of research for many years. In this paper,a method for urban spatial modeling and reasoning that provide valuable intellectual aids for sorting out different spatial problems is presented. In particular,the goal of this paper is to show the interest of a model based on Rectangle-trees (R-trees)for solving spatial map queries in digital cartography,where spatial aspect is privileged.By spatial queries here we mean :point-in-polygon queries,region queries and path queries.A knowledge based system that uses computational geometry based rules is employed for solving such queries.