Category theory : definitions and examples

Category theory was invented as an abstract language for describing certain structures and constructions which repeatedly occur in many branches of mathematics, such as topology, algebra, and logic. In recent years, it has found several applications in computer science, e.g., algebraic specification, type theory, and programming language semantics. In this paper, we collect definitions and examples of the basic concepts in category theory: categories, functors, natural transformations, universal properties, limits, and adjoints

Some Novel Applications of Explanation-Based Learning to Parsing Lexicalized Tree-Adjoining Grammars

In this paper we present some novel applications of Explanation-Based Learning (EBL) technique to parsing Lexicalized Tree-Adjoining grammars. The novel aspects are (a) immediate generalization of parses in the training set, (b) generalization over recursive structures and (c) representation of generalized parses as Finite State Transducers. A highly impoverished parser called a ``stapler'' has also been introduced. We present experimental results using EBL for different corpora and architectures to show the effectiveness of our approach.Comment: uuencoded postscript fil

Diagnosing Service Quality in Retailing: The Case of Singapore

This paper examines the service quality perceptions of consumers towards retailers in Singapore. We applied SERVQUAL, a popular measure of service quality to a sample of 172 consumers to assess service quality perceptions, expectations and gaps in service quality. We first examined the dimensionality and reliability of this scale. Subsequently, analysis by various demographic groups revealed significant gaps in service quality; the gaps in quality were much higher for some service quality dimensions than for others. The implications of these results for Singapore retailers and retail entrepreneurs are then presented along with future research directions