Mannila 11] cites as an open problem in Data Mining the problem of nding all minimal keys in a relation instance using only time that is polynomial in the number of relation attributes and number of minimal keys and sub-quadratic in the size of the relation instance. This paper investigates the eecacy of an \A Priori"-type approach to the problem, applied simultaneously in a level-wise top-down...

The paper describes a method of relation extraction , which is based on parsing the input text using a combination of a generic HPSG-based grammar and a highly focused domain-and relation-specific lexicon. We also show a method of unsupervised acquisition of such a lexicon from a large unla-beled corpus. Together, the methods introduce a novel approach to the " Open IE " task, which is superior...

Jan Renkema, in his Introduction to Discourse Studies, describes current research in coherence relations (also called rhetorical or discourse relations), and lists a few open questions in that area. One of the most important issues, from both a theoretical and applied point of view, is the signaling of relations, that is, the explicit marking of the presence of a relation. In this paper, I ques...

The Web brings an open-ended set of semantic relations. Discovering the significant types is very challenging. Unsupervised algorithms have been developed to extract relations from a corpus without knowing the relation types in advance, but most of them rely on tagging arguments of predefined types. One recently reported system is able to jointly extract relations and their argument semantic cl...

This paper restates the results on fuzzy relation equations with sup-inf composition from the viewpoint of decomposition, presents a way to describe the solution set of fuzzy relation equations, and shows a necessary and sufficient condition, which partly answers the open problem for existence of minimal solutions over complete Brouwerian lattices. Keywords— Complete Brouwerian lattice, fuzzy r...

We show that the isomorphism relation for finitely generated solvable groups of class 3 is a weakly universal countable Borel equivalence relation. This improves on previous results. The proof uses a modification of a construction of Neumann and Neumann. Elementary arguments show that isomorphism of finitely generated metabelian or nilpotent groups can not achieve this Borel complexity. In this...

This paper analyses the notion of a positivity relation of Formal Topology from the point of view of the theory of Locales. It is shown that a positivity relation on a locale corresponds to a suitable class of points of its lower powerlocale. In particular, closed subtopologies associated to the positivity relation correspond to overt (that is, with open domain) weakly closed sublocales. Finall...

Objective. The aim of this study is to determine the cephalometric features for a sample of Yemeni adults with anterior open bite. Material and Methods. Lateral cephalometric radiographs were taken for 65 Yemeni university students (46 males and 19 females), 18-25 years old, with clinical anterior open bite (vertical overbite ≤ 0 mm) and no previous orthodontic treatment. The radiographs were m...