Brief articles on topological regular solids giving a proof of Euler's Theorem and the Regularity Theorem; calculus theorems; including a limit theorem, the Law of the Man, and the Intermediate Value Theorem, applied to catching calves, drunk cowboys, and the border of Montana Respectively; and a discussion of the inequality tan A<A<sin A…

Examples are given of the usefulness of mathematics in several different fields. (MM)

The origin and evolution of the four-color problem are traced and the proof of the problem is outlined. (DT)

Explains the use of a topological structure to examine the closeness between documents in retrieval systems and analyzes the topological structure of a vector-space model, a fuzzy-set model, an extended Boolean model, a probabilistic model, and a TIRS (Topological Information Retrieval System) model. Proofs for the results are appended. (17…

Recorded are some biographical data about the late professor Freudenthal along with some indications about his mathematical work. In an appendix, a tiny part of his mathematical work which can be explained in a fairly direct manner is discussed. (Author)

Discussion of citation analysis on the Web considers Web hyperlinks as a source to analyze citations. Topics include basic graph theory applied to Web pages, including matrices, linear algebra, and Web topology; and hubs and authorities, including a search technique called HITS (Hyperlink Induced Topic Search). (Author/LRW)

This paper deals with a prey-predator model incorporating a prey refuge and harvesting of the predator species. A mathematical analysis shows that prey refuge plays a crucial role for the survival of the species and that the harvesting effort on the predator may be used as a control to prevent the cyclic behaviour of the system. The optimal…

The material in this booklet is concerned with a discussion and examination of geometric puzzles and the ideas which result from their study. The general idea of graphs is introduced as a tool which can be used to solve geometric puzzles. The fact that working with puzzles can lead to unexpected mathematical discoveries is stressed. Such topics as…

Chemical structures can be expressed unambiguously with both the atom connectivity matrix and its characteristic polynomial. (8 references) (Author)

Directed graph theory is used to find the number of ways of building a rectangular parallelepiped from six rectangular boards using simple overlap joints. (MM)

Three illustrations of the use of Euler circuits. (MM)

Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)