The interplay between models and observations

We propose a formal framework to examine the relationship between models and observations. To make our analysis precise, models are reduced to first-order theories that represent both terminological knowledge-e.g., the laws that are supposed to regulate the domain under analysis and that allow for explanations, predictions, and simulations-and assertional knowledge-e.g., information about specific entities in the domain of interest. Observations are introduced into the domain of quantification of a distinct first-order theory that describes their nature and their organization and takes track of the way they are experimentally acquired or intentionally elaborated. A model mainly represents the theoretical knowledge or hypotheses on a domain, while the theory of observations mainly represents the empirical knowledge and the given experimental practices. We propose a precise identity criterion for observations and we explore different links between models and observations by assuming a degree of independence between them. By exploiting some techniques developed in the field of social choice theory and judgment aggregation, we sketch some strategies to solve inconsistencies between a given set of observations and the assumed theoretical hypotheses. The solutions of these inconsistencies can impact both the observations-e.g., the theoretical knowledge and the analysis of the way observations are collected or produced may highlight some unreliable sources-and the models-e.g., empirical evidences may invalidate some theoretical law

Ages and Metallicities of Fornax Dwarf Ellipticals

Narrow band photometry is presented on 27 dwarf ellipticals in the Fornax cluster. Calibrated with Galactic globular cluster data and spectrophotometric population models, the colors indicated that dwarf ellipticals have a mean [Fe/H] of -1.00+/-0.28 ranging from -1.6 to -0.4. The mean age of dwarf ellipticals, also determined photometrically, is estimated at 10+/-1 Gyrs compared to 13 Gyrs for bright Fornax ellipticals. Comparison of our metallicity color and Mg_2 indices demonstrates that the [Mg/Fe] ratio is lower in dwarf ellipticals than their more massive cousins, which is consistent with a longer duration of initial star formation to explain their younger ages. There is a increase in dwarf metallicity with distance from the Fornax cluster center where core galaxies are, on average, 0.5 dex more metal-poor than halo dwarfs. In addition, we find the halo dwarfs are younger in mean age compared to core dwarfs. One possible explanation is that the intracluster medium ram pressure strips the gas from dwarf ellipticals halting star formation (old age) and stopping enrichment (low metallicity) as they enter the core.Comment: 40 pages AAS LaTeX, 14 figures, accepted for publication in A

Needs and intentionality

A thorough understanding of what needs are is fundamental for design- ing well-behaved information systems for many social applications and in partic- ular for public services. Talking about needs pervades indeed the jargon of Public Administrations when motivating their service offering. In this paper, we propose an ontological analysis of needs, aiming at a principled disentangling of the differ- ent uses of the term. We leverage philosophical tradition on intentionality, for its rich understanding of mental entities, we compare it with the well-established BDI (Belief-Desire-Intention) tradition in knowledge representation, and we propose a formalisation of needs within the foundational ontology DOLCE. Throughout the paper, we motivate our analysis focusing on needs in public services

Pluralities, Collectives, and Composites

Forests, cars and orchestras are very different ontological entities, and yet very similar in some aspects. The relationships they have with the elements they are composed of is often assumed to be reducible to standard ontological relations, like parthood and constitution, but how this could be done is still debated. This paper sheds light on the issue starting from a linguistic and philosophical analysis aimed at understanding notions like plurality, collective and composite, and propos- ing a formal approach to characterise them. We conclude the presentation with a discussion and analysis of social groups within this framework

Procedurally Rhetorical Verb-Centric Frame Semantics as a Knowledge Representation for Argumentation Analysis of Biochemistry Articles

The central focus of this thesis is rhetorical moves in biochemistry articles. Kanoksilapatham has provided a descriptive theory of rhetorical moves that extends Swales' CARS model to the complete biochemistry article. The thesis begins the construction of a computational model of this descriptive theory. Attention is placed on the Methods section of the articles. We hypothesize that because authors' argumentation closely follows their experimental procedure, procedural verbs may be the guide to understanding the rhetorical moves. Our work proposes an extension to the normal (i.e., VerbNet) semantic roles especially tuned to this domain. A major contribution is a corpus of Method sections that have been marked up for rhetorical moves and semantic roles. The writing style of this genre tends to occasionally omit semantic roles, so another important contribution is a prototype ontology that provides experimental procedure knowledge for the biochemistry domain. Our computational model employs machine learning to build its models for the semantic roles and rhetorical moves, validated against a gold standard reflecting the annotation of these texts by human experts. We provide significant insights into how to derive these annotations, and as such have contributions as well to the general challenge of producing markups in the domain of biomedical science documents, where specialized knowledge is required