45,055 research outputs found
A Review of integrity constraint maintenance and view updating techniques
Two interrelated problems may arise when updating a database. On one
hand, when an update is applied to the database, integrity constraints
may become violated. In such case, the integrity constraint maintenance
approach tries to obtain additional updates to keep integrity
constraints satisfied. On the other hand, when updates of derived or
view facts are requested, a view updating mechanism must be applied to
translate the update request into correct updates of the underlying base
facts.
This survey reviews the research performed on integrity constraint
maintenance and view updating. It is proposed a general framework to
classify and to compare methods that tackle integrity constraint
maintenance and/or view updating. Then, we analyze some of these methods
in more detail to identify their actual contribution and the main
limitations they may present.Postprint (published version
A logic programming framework for modeling temporal objects
Published versio
Ontology-based model abstraction
In recent years, there has been a growth in the use of reference conceptual models to capture information about complex and critical domains. However, as the complexity of domain increases, so does the size and complexity of the models that represent them. Over the years, different techniques for complexity management in large conceptual models have been developed. In particular, several authors have proposed different techniques for model abstraction. In this paper, we leverage on the ontologically well-founded semantics of the modeling language OntoUML to propose a novel approach for model abstraction in conceptual models. We provide a precise definition for a set of Graph-Rewriting rules that can automatically produce much-reduced versions of OntoUML models that concentrate the modelsā information content around the ontologically essential types in that domain, i.e., the so-called Kinds. The approach has been implemented using a model-based editor and tested over a repository of OntoUML models
Metatheory and Friendly Competition in Theory Growth: The Case of Power Processes in Bargaining
[Excerpt] This paper analyzes the theoretical development taking place in a program of research on power processes in bargaining (see Bacharach and Lawler 1976, 1980, 1981a, 1981b; Lawler and Bacharach 1976, 1979, 1987; Lawler, Ford, and Blegen 1988; Lawler and Yoon 1990; Lawler 1986, 1992). The theoretical program takes as its starting point a situation where individuals, groups, organizations, or even societies with conflicting interests voluntarily enter into explicit bargaining. Explicit (as opposed to tacit) bargaining assumes the mutual acknowledgment of negotiations, conflicting issues along which compromise is possible, and open lines of communication through which parties can exchange offers and counteroffers in an attempt to resolve the issues that divide them (Schelling 1960; Bacharach and Lawler 1980; Boyle and Lawler 1991). The scope of this theoretical research program assumes further that the parties have a power capability, that they use this power tactically in an effort to achieve desired outcomes, and that they strive for a favorable position during the bargaining process
Web and Semantic Web Query Languages
A number of techniques have been developed to facilitate
powerful data retrieval on the Web and Semantic Web. Three categories
of Web query languages can be distinguished, according to the format
of the data they can retrieve: XML, RDF and Topic Maps. This article
introduces the spectrum of languages falling into these categories
and summarises their salient aspects. The languages are introduced using
common sample data and query types. Key aspects of the query
languages considered are stressed in a conclusion
On the Probability of Plenitude
I examine what the mathematical theory of random structures can teach us about the probability of Plenitude, a thesis closely related to David Lewis's modal realism. Given some natural assumptions, Plenitude is reasonably probable a priori, but in principle it can be (and plausibly it has been) empirically disconfirmedānot by any general qualitative evidence, but rather by our de re evidence
Bidirectionalization for Free with Runtime Recording: Or, a Light-Weight Approach to the View-Update Problem
A bidirectional transformation is a pair of mappings between source and view data objects, one in each direction. When the view is modified, the source is updated accordingly with respect to some laws. Over the years, a lot of effort has been made to offer better language support for programming such transformations. In particular, a technique known as bidirectionalization is able to analyze and transform unidirectional programs written in general purpose languages, and "bidirectionalize" them.
Among others, a technique termed as semantic bidirectionalization proposed by VoigtlƤnder stands out in term of user-friendliness. The unidirectional program can be written using arbitrary language constructs, as long as the function is polymorphic and the language constructs respect parametricity. The free theorems that follow from the polymorphic type of the program allow a kind of forensic examination of the transformation, determining its effect without examining its implementation. This is convenient, in the sense that the programmer is not restricted to using a particular syntax; but it does require the transformation to be polymorphic.
In this paper, we lift this polymorphism requirement to improve the applicability of semantic bidirectionalization. Concretely, we provide a type class PackM Ī³ Ī± Ī¼, which intuitively reads "a concrete datatype Ī³ is abstracted to a type Ī±, and the 'observations' made by a transformation on values of type Ī³ are recorded by a monad Ī¼". With PackM, we turn monomorphic transformations into polymorphic ones, that are ready to be bidirectionalized. We demonstrate our technique with a case study of standard XML queries, which were considered beyond semantic bidirectionalization because of their monomorphic nature
- ā¦