Miguel R. Penabad

The Galician virtual library

Purpose – This study aims to present the digital library Galician virtual library (BVG, for “Biblioteca Virtual Galega”) in Galician.Design/methodology/approach – The paper shows the objectives pursued by the BVG, its development, putting special emphasis on the main technological challenges, and presents some data about its usage.Findings – A digital library can be used to stimulate a lesser‐used language and to promote the culture and tourism of a region.Originality/value – The paper shows how a digital library can be used to strengthen the Galician language, which is currently categorised as a “Lesser Used Language” in the European Community and to contribute to the preservation and spreading of Galician culture and literary works, either from current authors or from previous documents. It also provides a digital publishing house for new authors and opens a communication channel between current authors and their readers. Finally, it helps to connect a scattered community like the Galician, offering a c...

A General procedure to test conjunctive query containment

Abstract. In this paper, we present a general procedure to test conjunctive query containment. We divide the containment problem into four categories, taking into account the underlying semantics (set or bag theoretic) and the presence or absence of built-in predicates in the queries.After a brief review of previous work on conjunctive query containment, we present a new procedure, called QCC (Query Containment Checker), which we show to be a general and uniform procedure to check the containment among conjunctive queries under the four categories mentioned above. We briefly describe the use of QCC to check bag containment of conjunctive queries, and explain in detail how to use QCC to check set containment of conjunctive queries with built-in predicates. In our conclusions, we point out some uses of QCC for other types of containment.

Using geographical information systems to browse touristic information.

The current expansion of Internet makes it one of the most popular places to publish and search for almost any kind of information. In particular, touristic information, not only about tours or information about resources, places, museums or monuments, but also cultural tourism, has gained much attention in the last years. We propose the use of geographical information systems technology (GIS) that provides interfaces capable of displaying interactive maps with information associated to the elements present in such maps. In this paper, we present a Web interface to access touristic information about Galicia (Spain) using GIS technology to easily find any touristic or cultural information. This interface is enclosed in the Galician Virtual Library (http://bvg.udc.es) Web site.

A documental database query language

This work presents a natural language based technique to build user interfaces to query document databases through the web. We call such technique Bounded Natural Language (BNL). Interfaces based on BNL are useful to query document databases containing only structured data, containing only text or containing both of them. That is, the underlying formalism of BNL can integrate restrictions over structured and non-structured data (as text).Interfaces using BNL can be programmed ad hoc for any document database but in this paper we present a system with an ontology based architecture in which the user interface is automatically generated by a software module (User Interface Generator) capable of reading and following the ontology. This ontology is a conceptualization of the database model, which uses a label in natural language for any concept in the ontology. Each label represents the usual name for a concept in the real world.The ontology includes general concepts useful when the user is interested in documents in any corpus in the database, and specific concepts useful when the user is interested in a specific corpus. That is, databases can store one or more corpus of documents and queries can be issued either over the whole database or over a specific corpus.The ontology guides the execution of the User Interface Generator and other software modules in such a way that any change in the database does not imply making changes in the program code, because the whole system runs following the ontology. That is, if a modification in the database schema occurs, only the ontology must be changed and the User Interface Generator will produce a new and different user interface adapted to the new database.

Containment of Conjunctive Queries with Built-in Predicates with Variables and Constants over any Ordered Domain

In this paper, we consider conjunctive queries with built-in predicates of the form X < Y, X ≤ Y, X = Y, or X ⊋ Y, where X and Y are variables or constants from a totally ordered domain. We present a sufficient and necessary condition to test containment among these kinds of queries. Klug [8] left the problem open for the case when the domain is nondense, like the integers. Ullman [11] gave only a sufficient condition for the containment of conjunctive queries with built-in predicates and integer variables. Our test is based in a method that uses a new idea: the representation of an infinite number of databases by a finite set of, what we call, canonical databases, that use variables that denote uninterpreted constants.

Solving Language Problems in a Multilingual Digital Library Federation

This work presents an architecture to federate pre-existing Digital Libraries with documents written in different languages. A user will be able to ask queries to all the federated Digital Libraries using a unique and friendly user interface that will be generated in the language she chooses among the available ones. The query will be executed over all the relevant databases in the system no matter which language their documents are written in. The query will be automatically translated if it is necessary. This architecture is based on ontologies, which are used not only to represent the global schema but also to guide the execution of software modules in the system; it also includes three dictionaries to solve the inter-language barriers.

Tools for the Design of User Friendly Web Applications

The usability ofWeb pages and applications is a fundamental factor in their success. Web designers are taking advantage of the new technologies (scripting languages, Java, etc.) to increase the power, user friendliness and easiness of use of Web pages. This work presents two techniques that can be used to achieve this goal: the use of cognitive metaphors to build user interfaces, and the use of Bounded Natural Language, to allow the user to express queries in an intuitive way.

Implication of Functional Dependencies for Recursive Queries

After two decades of research in Deductive Databases, SQL99 [12] brings them again to the foreground given that SQL99 includes queries with linear recursion. Therefore some of the problems solved for the relational model demand our attention again.

A Semantic Query Optimization Approach to Optimize Linear Datalog Programs

After two decades of research in Deductive Databases, SQL99 brings deductive databases again to the foreground given that SQL99 includes queries with linear recursion. However, the execution of recursive queries may result in slow response time, thus the research in query optimization is very important to provide the suitable algorithms that will be included in the query optimizers of the database management systems in order to speed up the execution of recursive queries. We use a semantic query optimization approach in order to improve the efficiency of the evaluation of datalog programs. Our main contribution is an algorithm that builds a program P? equivalent to a given program P, when both are applied over a database d satisfying a set of functional dependencies. The input program P is a linear recursive datalog program. The new program P? has less number of different variables and, sometimes, less number of atoms in the recursive rules, thus it is cheaper to evaluate.

EECB: a knowledge elicitation tool based on repertory grid and city block metric

Abstract There are several knowledge acquisition tools that use repertory grids as a technique to elicitate knowledge. One of the steps involved in this technique is the debugging of the grid using procedures based on cluster analysis. Most of these tools employ a Euclidean metric for the clustering. However, some authors find evidence that people use the city block metric when rating similarities. In this paper, the tool ComPar ( Comparacion de Pares ), developed to acquire data in a knowledge engineering experiment, is described. This tool tries to determine what kind of metric is the most often used by people in similarity judgments. After the experiment, it was concluded that there is evidence that individuals use mainly a city block metric when trying to judge similarity between different things. Accordingly, a tool supporting the repertory grid technique called EECB ( emparrillado euclideo , “city block” in Spanish) was developed afterwards, allowing the possibility of distance calculations using city block metric.