808 research outputs found
Type-Based Detection of XML Query-Update Independence
This paper presents a novel static analysis technique to detect XML
query-update independence, in the presence of a schema. Rather than types, our
system infers chains of types. Each chain represents a path that can be
traversed on a valid document during query/update evaluation. The resulting
independence analysis is precise, although it raises a challenging issue:
recursive schemas may lead to infer infinitely many chains. A sound and
complete approximation technique ensuring a finite analysis in any case is
presented, together with an efficient implementation performing the chain-based
analysis in polynomial space and time.Comment: VLDB201
Building, Testing and Assessing a Learning Management System
This paper summarizes the experiences of our research group in managing the full process of building, testing and assessing a Learning Management System for a educational institution. We will show how we moved across the âmake or buyâ dilemma that normally educational institutions have to face when deciding to implement a support for online and distance learning activities. We will deal with this theme by referring to systems and prototypes developed by our research group. Specifically, we will describe our experiences in realizing systems for making didactic material available on Internet, such as in the Learning Management Systems - LMS. This experience is based on what has been developed, tested, and put to use in some faculties of the University of Trento, where non-traditional learning environments in which students require more than the traditional face-to-face lessons are becoming ever more important. The prototypes produced are based on platform-independent technologies, and they make it possible to broaden oneâs horizons, even for those students, such as lifelong learners, who want freedom from time constraints and also freedom from some technological constraints that are imposed by some forms of distance education currently available on the market. Some extensions to mobile tools like PDA, tablet PC, cellular phones etc. are presented, with regards to the impact of their introduction on the LMS and in general on the information system of the institution
XML content warehousing: Improving sociological studies of mailing lists and web data
In this paper, we present the guidelines for an XML-based approach for the
sociological study of Web data such as the analysis of mailing lists or
databases available online. The use of an XML warehouse is a flexible solution
for storing and processing this kind of data. We propose an implemented
solution and show possible applications with our case study of profiles of
experts involved in W3C standard-setting activity. We illustrate the
sociological use of semi-structured databases by presenting our XML Schema for
mailing-list warehousing. An XML Schema allows many adjunctions or crossings of
data sources, without modifying existing data sets, while allowing possible
structural evolution. We also show that the existence of hidden data implies
increased complexity for traditional SQL users. XML content warehousing allows
altogether exhaustive warehousing and recursive queries through contents, with
far less dependence on the initial storage. We finally present the possibility
of exporting the data stored in the warehouse to commonly-used advanced
software devoted to sociological analysis
The WebStand Project
In this paper we present the state of advancement of the French ANR WebStand
project. The objective of this project is to construct a customizable XML based
warehouse platform to acquire, transform, analyze, store, query and export data
from the web, in particular mailing lists, with the final intension of using
this data to perform sociological studies focused on social groups of World
Wide Web, with a specific emphasis on the temporal aspects of this data. We are
currently using this system to analyze the standardization process of the W3C,
through its social network of standard setters
On derived-indecomposable solutions of the Yang--Baxter equation
If is a finite non-degenerate set-theoretic solution of the
Yang--Baxter equation, the additive group of the structure skew brace
is an -group, i.e. a group whose elements have finitely many conjugates.
Moreover, its multiplicative group is virtually abelian, so it is also close to
an -group itself. If one additionally assumes that the derived solution of
is indecomposable, then for every element of there are
finitely many elements of the form and , with . This
naturally leads to the study of a brace-theoretic analogue of the class of
-groups. For this class of skew braces, the fundamental results and their
connections with the solutions of the YBE are described: we prove that they
have good torsion and radical theories and they behave well with respect to
certain nilpotency concepts and finite generation.Comment: 24 pages. Accepted for publication in Publicacions Matem\`atique
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