688 research outputs found
Space-contained conflict revision, for geographic information
Using qualitative reasoning with geographic information, contrarily, for
instance, with robotics, looks not only fastidious (i.e.: encoding knowledge
Propositional Logics PL), but appears to be computational complex, and not
tractable at all, most of the time. However, knowledge fusion or revision, is a
common operation performed when users merge several different data sets in a
unique decision making process, without much support. Introducing logics would
be a great improvement, and we propose in this paper, means for deciding -a
priori- if one application can benefit from a complete revision, under only the
assumption of a conjecture that we name the "containment conjecture", which
limits the size of the minimal conflicts to revise. We demonstrate that this
conjecture brings us the interesting computational property of performing a
not-provable but global, revision, made of many local revisions, at a tractable
size. We illustrate this approach on an application.Comment: 14 page
Locative and Directional Prepositions in Conceptual Spaces: The Role of Polar Convexity
© 2015, The Author(s). We approach the semantics of prepositions from the perspective of conceptual spaces. Focusing on purely spatial locative and directional prepositions, we analyze both types of prepositions in terms of polar coordinates instead of Cartesian coordinates. This makes it possible to demonstrate that the property of convexity holds quite generally in the domain of prepositions of location and direction, supporting the important role that this property plays in conceptual spaces
A prototype-based resonance model of rhythm categorization
Categorization of rhythmic patterns is prevalent in musical practice, an example of this being the transcription of (possibly not strictly metrical) music into musical notation. In this article we implement a dynamical systems' model of rhythm categorization based on the resonance theory of rhythm perception developed by Large (2010). This model is used to simulate the categorical choices of participants in two experiments of Desain and Honing (2003). The model accurately replicates the experimental data. Our results support resonance theory as a viable model of rhythm perception and show that by viewing rhythm perception as a dynamical system it is possible to model central properties of rhythm categorization
Counting Popular Matchings in House Allocation Problems
We study the problem of counting the number of popular matchings in a given
instance. A popular matching instance consists of agents A and houses H, where
each agent ranks a subset of houses according to their preferences. A matching
is an assignment of agents to houses. A matching M is more popular than
matching M' if the number of agents that prefer M to M' is more than the number
of people that prefer M' to M. A matching M is called popular if there exists
no matching more popular than M. McDermid and Irving gave a poly-time algorithm
for counting the number of popular matchings when the preference lists are
strictly ordered.
We first consider the case of ties in preference lists. Nasre proved that the
problem of counting the number of popular matching is #P-hard when there are
ties. We give an FPRAS for this problem.
We then consider the popular matching problem where preference lists are
strictly ordered but each house has a capacity associated with it. We give a
switching graph characterization of popular matchings in this case. Such
characterizations were studied earlier for the case of strictly ordered
preference lists (McDermid and Irving) and for preference lists with ties
(Nasre). We use our characterization to prove that counting popular matchings
in capacitated case is #P-hard
Knowing, Learning and Teaching - How Homo Became Docens
Copyright © The McDonald Institute for Archaeological Research. This article discusses the relation between knowing, learning and teaching in relation to early Palaeolithic technologies. We begin by distinguishing between three kinds of knowledge: knowing how, knowing what and knowing that. We discuss the relation between these types of knowledge and different forms of learning and long-term memory systems. On the basis of this analysis, we present three types of teaching: (1) helping and correcting; (2) showing; and (3) explaining. We then use this theoretical framework to suggest what kinds of teaching are required for the pre-Oldowan, the Oldowan, the early Acheulean and the late Acheulean stone-knapping technologies. As a general introductory overview to this special section, the text concludes with a brief presentation of the papers included
RankPL: A Qualitative Probabilistic Programming Language
In this paper we introduce RankPL, a modeling language that can be thought of
as a qualitative variant of a probabilistic programming language with a
semantics based on Spohn's ranking theory. Broadly speaking, RankPL can be used
to represent and reason about processes that exhibit uncertainty expressible by
distinguishing "normal" from" surprising" events. RankPL allows (iterated)
revision of rankings over alternative program states and supports various types
of reasoning, including abduction and causal inference. We present the
language, its denotational semantics, and a number of practical examples. We
also discuss an implementation of RankPL that is available for download
Topological Aspects of Epistemology and Metaphysics
The aim of this paper is to show that (elementary) topology may be useful for dealing with problems of epistemology and metaphysics. More precisely, I want to show that the introduction of topological structures may elucidate the role of the spatial structures (in a broad sense) that underly logic and cognition. In some detail Iâll deal with âCassirerâs problemâ that may be characterized as an early forrunner of Goodmanâs âgrue-bleenâ problem. On a larger scale, topology turns out to be useful in elaborating the approach of conceptual spaces that in the last twenty years or so has found quite a few applications in cognitive science, psychology, and linguistics. In particular, topology may help distinguish ânaturalâ from ânot-so-naturalâ concepts. This classical problem that up to now has withstood all efforts to solve (or dissolve) it by purely logical methods. Finally, in order to show that a topological perspective may also offer a fresh look on classical metaphysical problems, it is shown that Leibnizâs famous principle of the identity of indiscernibles is closely related to some well-known topological separation axioms. More precisely, the topological perspective gives rise in a natural way to some novel variations of Leibnizâs principle
Popular matchings with two-sided preferences and one-sided ties
We are given a bipartite graph where each vertex has a
preference list ranking its neighbors: in particular, every ranks its
neighbors in a strict order of preference, whereas the preference lists of may contain ties. A matching is popular if there is no matching
such that the number of vertices that prefer to exceeds the number of
vertices that prefer to~. We show that the problem of deciding whether
admits a popular matching or not is NP-hard. This is the case even when
every either has a strict preference list or puts all its neighbors
into a single tie. In contrast, we show that the problem becomes polynomially
solvable in the case when each puts all its neighbors into a single
tie. That is, all neighbors of are tied in 's list and desires to be
matched to any of them. Our main result is an algorithm (where ) for the popular matching problem in this model. Note that this model
is quite different from the model where vertices in have no preferences and
do not care whether they are matched or not.Comment: A shortened version of this paper has appeared at ICALP 201
Popular Matchings in the Capacitated House Allocation Problem
We consider the problem of finding a popular matching in the Capacitated House Allocation problem (CHA). An instance of CHA involves a set of agents and a set of houses. Each agent has a preference list in which a subset of houses are ranked in strict order, and each house may be matched to a number of agents that must not exceed its capacity. A matching M is popular if there is no other matching MâČ such that the number of agents who prefer their allocation in MâČ to that in M exceeds the number of agents who prefer their allocation in M to that in MâČ. Here, we give an O(âC+n1m) algorithm to determine if an instance of CHA admits a popular matching, and if so, to find a largest such matching, where C is the total capacity of the houses, n1 is the number of agents and m is the total length of the agentsâ preference lists. For the case where preference lists may contain ties, we give an O(âCn1+m) algorithm for the analogous problem
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