Semantic similarity measures play an important role in information retrieval and information integration. Traditional approaches to modeling semantic similarity compute the semantic distance between definitions within a single ontology. This single ontology is either a domain-independent ontology or the result of the integration of existing ontologies. We present an approach to computing semantic similarity that relaxes the requirement of a single ontology and accounts for differences in the levels of explicitness and formalization of the different ontology specifications. A similarity function determines similar entity classes by using a matching process over synonym sets, semantic neighborhoods, and distinguishing features that are classified into parts, functions, and attributes. Experimental results with different ontologies indicate that the model gives good results when ontologies have complete and detailed representations of entity classes. While the combination of word matching and semantic neighborhood matching is adequate for detecting equivalent entity classes, feature matching allows us to discriminate among similar, but not necessarily equivalent, entity classes.

INTRODUCTION This is a brief overview of formal theories concerned with the study of the notions of (and the relations between) parts and wholes. The guiding idea is that we can distinguish between a theory of parthood (mereology) and a theory of wholeness (holology, which is essentially afforded by topology), and the main question examined is how these two theories can be combined to obtain a unified theory of parts and wholes. We examine various non-equivalent ways of pursuing this task, mainly with reference to its relevance to spatio-temporal reasoning. In particular, three main strategies are compared: (i) mereology and topology as two independent (though mutually related) theories; (ii) mereology as a general theory subsuming topology; (iii) topology as a general theory subsuming mereology. This is done in Sections 4 through 6. We also consider some more speculative strategies and directions for further research. First, however, we begin with some preliminary outline of

this paper. V 0 ! #"$ &' )* + , -. / 0213 124 67 8 9: ;< => ?!@#AB DE F GH I J KL M NPOQORTSU2V X YZ [ \ ]_^ ` \ ]_^ ` aPbcbdfegh ifh jh k lTej dfmnh j_h k o ejdkj_h epfq r sdfm t um pjh u2e sdfm t um pjh ueruct r aPbQbdTeg2h v wx#y{z | }~x{ } wx#y{z | }~x } wx#y_z }~x{ }_ wx#y_z | }~nx } yz x !} y_z x | x{ }{{yw Q Q !# 2 - !# _ _ 2Tnc - fcQ fQc #{ { #{  _{ 2 # _{ 2 # _{ 2 # _{ 2 # _{ 2 # Figure 2: Enabling/Disabling Role Propagation in a SEP-Encoded Partonomy across part-whole hierarchies is disabled, in the second case it is enabled. As an example (cf. Figure 2), Enteritis is defined as has-location Intestine , i.e., the range of the relation has-location is restricted to the E-node of Intestine. This precludes, e.g., the classification of Appendicitis as Enteritis though the Appendix is related to the Intestine via an anatomical-part-of relation. In the `switch-on' mode, however, Glomerulonephritis (has-location Glomerulum ) is classified as Nephritis (has- location Kidney ), with Glomerulum being an anatomical-part-of the Kidney. In the same way, Perforation-of-Appendix is classified as Intestinal-Perforation (cf. Hahn et al. for an in-depth analysis of these phenomena)

The whole-part organizational method is one which pervades human thinking, and as such plays an important role in data modeling. This is especially true in manufacturing, design, graphics, multimedia, and document processing---areas targeted by object-oriented databases (OODBs). In this paper, we formally define OODB relationships which provide constraints and functionalities that enforce realworld, whole-part interactions between objects of the database. These OODB "part" relationships capture a variety of semantics including exclusiveness/sharing, single-/multi-valuedness, cardinality range-restriction, ordering of definite or indefinite number, essentiality, dependency, and value propagation. For each kind of relationship, we present a graphical symbol which enhances an OODB graphical schema representation that we have previously developed. Among the part relationships presented, two of them, the global exclusive and the class exclusive, refine the notion of exclusiveness between wh...

Guarino for their prompt responses to my questions. Third, to all my colleagues and friends in the Department of Spatial Information Science I would like to thank you for sharing the good and bad moments of my study life. I feel fortunate for having being part of a friendly environment that made my Ph.D. program an enjoyable and unforgettable experience. iii Fourth, I thank the support and funding from the University of Concepcin, Chile, and the initial funding from the Fulbright foundation. Further funding from the National Center of Geographic Information and Analysis, the National Imagery and Mapping Agency, and Lockheed Martin are gratefully acknowledged. Most important, I thank the continuous support, love, and patience of Christian and Alicia. This long journey would not have been possible without them. iv Table of Contents Acknowledgments .......................................................................................................ii List of Figu

Incorporating abstraction methods, such as aggregation and association, into information system design methodologies has improved our ability to model the real world. The semantically-higher level objects that result from these abstractions are referred to as composite objects. These objects play an important role in spatio-temporal knowledge representation and query formulation, although little has been done so far on formalizing operations involving these types of objects. In this investigation, the semantics associated with composite objects are explored as is the role of object identity for composite objects. Object identity refers to that trait which distinguishes an object from all others. The different semantics associated with creating composite objects and adding parts to composites are discussed and a set of basic identity-based change operations for composites, including separation and elimination operations, are described. Formalizing the operations relating to composite objects aids in improving current spatial data models and leads to advances in spatial-temporal query languages.

Mereotopology is today regarded as a major tool for ontological analysis, and for many good reasons. There are, however, a number of open questions that call for an answer. Some of them are philosophical, others have direct import for applications, but all are crucial for a proper assessment of the strengths and limits of mereotopology. This paper is an attempt to put some order into this still untamed area of research. I will not attempt any answers. But I shall try to give an idea of the problems, and of their relevance for the systematic development of formal ontological theories.

this paper we present an alternative account, based primarily on the basic network of formal ontological relations---specifically, mereological and topological relations---that a domain of events must arguably satisfy. The motivations for this approach are quite general and lie beyond the specific issue of temporal constructions. Among other things, we also believe it may shed light on the first question above. In the following, however, we shall not go much beyond the main issue that we just outlined; our only concern will be to show how mereological and topological reasoning---which we take to be among the basic tools for ontological analysis---provides adequate grounds for the construction of temporal relations.

Abstract. That parthood is a transitive relation is among the most basic principles of classical mereology. Alas, it is also very controversial. In a recent paper, Ingvar Johansson has put forward a novel diagnosis of the problem, along with a corresponding solution. The diagnosis is on the right track, I argue, but the solution is misleading. And once the pieces are properly put together, we end up with a reinforcement of the standard defense of transitivity on behalf of classical mereology. 1. Is parthood transitive? Classical mereology says it is. If x is part of y and y is part of z, then x is part of z—no matter what x, y, and z are. Indeed, on standard models of extensional mereology, parthood is isomorphic to set inclusion, and there is no question that the latter relation is transitive. Nonetheless, an increasing number of authors have been protesting that many legitimate senses of ‘part ’ appear to violate this principle. Typical examples would include: (1) The handle is part of the door, which in turn is part of a house, but the handle itself is not part of the house.

A. The roots of mereology (from the Greek µερος, ‘part’) can be traced back to the early days of philosophy, beginning with the Presocratic atomists and continuing throughout the writings of Plato (esp. Parmenides and Thaetetus), Aristotle (esp. the Metaphysics, but also the Physics, the Topics, and De partibus animalium), and Boethius (esp. De Divisione and In Ciceronis Topica). Mereology has also occupied a prominent role in the writings of medieval ontologists and scholastic philosophers such as Garland the Computist, Peter Abelard, Thomas Aquinas, Raymond Lull, Walter Burley, and Albert of Saxony, as well as in Jungius’s Logica