This paper mainly proposes notions and methods of attribute reduction in concept lattices based on rough set theory. Using dependence space of concept lattices, we first discuss the relationships between congruence relations and the corresponding concept lattices. We then define notions of attribute reduction in a formal context based on congruence relations which is to find the minimal attribu...

The attribute hierarchy method (AHM) (Leighton, Gierl, & Hunka, 2004), which is based on the assumption that test items can be described by a set of hierarchically ordered attributes, is designed to estimate examinees’ level of competency as well as their profiles for mastering a set of attributes. The AHM, by incorporating the assumption of attribute dependency, brings an important cognitive p...

Collaborative recommender is the most popular recommendation technique nowadays and it mainly employs the user item rating data set. Traditional collaborative filtering approaches compute a similarity value between the target user and each other user by computing the relativity of their ratings, and they only consider the ratings information. User attribute information associated with a user's ...

In this paper we study the relationship between Attribute Grammars and Logic Programs, concentrating on transforming logic programs into attribute grammars. This has potential applications in compilation techniques for logic programs. It does not seem possible to transform arbitrary Logic Programs into Attribute Grammars, basically because the same logic variables can sometimes be used as input...