One of the most important elements in a lattice are the irreducible elements. For example, when the lattice is finite, which is usual in the computational case, it forms a base from which the complete lattice is obtained. These elements are also important in Formal Concept Analysis, since they are the basic information of a relational system. In the general fuzzy framework of multi-adjoint conc...

[Fu68] presents structures, in a finite relational type, with unique undefinable elements and recursive theories. We present somewhat simpler examples, with somewhat stronger properties. We also present structures, in a finite relational type, whose unique undefinable element is weak second order undefinable. We convert all examples of a similar nature to corresponding examples in the form of b...

Existing studies on information technology outsourcing relationships have typically examined partnership factors that influence IT outsourcing effectiveness. This research extends such studies and draws upon relational exchange theory to investigate how relational elements in service level agreements (SLAs) may impact outsourcing relationships. The results show that the effects of a well-struct...

The Multi-Relational Boolean factor analysis is a method from the family of matrix decomposition methods which enables us analyze binary multi-relational data, i.e. binary data which are composed from many binary data tables interconnected via relation. In this paper we present a new Boolean matrix factorization algorithm for this kind of data, which use the new knowledge from the theory of the...

Two experiments examined the role of relational language on analogical transfer. Participants were taught Signal Detection Theory (SDT) embedded in a doctor story. In the experimental condition, relational words accompanied the story. Relational words that shared superficial similarity with the contextual elements facilitated transfer. Without the shared semantics, relational words were detrime...

Let L be a non empty relational structure. One can check that idL is monotone. Let S, T be non empty relational structures and let f be a map from S into T . Let us observe that f is antitone if and only if: (Def. 1) For all elements x, y of S such that x ¬ y holds f(x) ­ f(y). Next we state several propositions: (1) Let S, T be relational structures, K, L be non empty relational structures, f ...

Ontology Based Data Access (OBDA) enables access to relational data with a complex structure through ontologies as conceptual domain models. A key component of an OBDA system are mappings between the schematic elements in the ontology and their correspondences in the relational schema. Today, in existing OBDA systems these mappings typically need to be compiled by hand. In this paper we present...

In this article we present several logical schemes. The scheme SubrelstrEx deals with a non empty relational structure A , a set B, and a unary predicate P , and states that: There exists a non empty full strict relational substructure S of A such that for every element x of A holds x is an element of S if and only if P [x] provided the following conditions are met: • P [B], and • B ∈ the carri...

Database reverse engineering (DBRE) recovers a database design using a semantic data model. Most of the existing works and tools for DBRE and database design specify relational database schemas with extended ER models. The Unified Modeling Language (UML) is a standard language for modeling software and database systems. We discuss how to extend the UML metamodel with elements for modeling relat...