113,315 research outputs found
Discovering Knowledge from Local Patterns with Global Constraints
It is well known that local patterns are at the core of a lot of
knowledge which may be discovered from data. Nevertheless, use of local
patterns is limited by
their huge number and computational costs. Several approaches (e.g.,
condensed representations, pattern set discovery) aim at grouping or
synthesizing local patterns to provide a global view of the data. A
global pattern is a pattern which is a set or a synthesis of local
patterns coming from the data. In this paper, we propose the idea of
global constraints to write queries addressing global patterns. A key
point is the ability to bias the designing of global patterns according
to the expectation of the user. For instance, a global pattern can be
oriented towards the search of exceptions or a clustering. It requires
to write queries taking into account such biases. Open issues are to
design a generic framework to express powerful global constraints and
solvers to mine them. We think that global constraints are a promising
way to discover relevant global patterns
Developmental disorders
Introduction: Connectionist models have recently provided a concrete computational platform from which to explore how different initial constraints in the cognitive system can interact with an environment to generate the behaviors we find in normal development (Elman et al., 1996; Mareschal & Thomas, 2000). In this sense, networks embody several principles inherent to Piagetian theory, the major developmental theory of the twentieth century. By extension, these models provide the opportunity to explore how shifts in these initial constraints (or boundary conditions) can result in the emergence of the abnormal behaviors we find in atypical development. Although this field is very new, connectionist models have already been put forward to explain disordered language development in Specific Language Impairment (Hoeffner & McClelland, 1993), Williams Syndrome (Thomas & Karmiloff-Smith, 1999), and developmental dyslexia (Seidenberg and colleagues, see e.g. Harm & Seidenberg, in press); to explain unusual characteristics of perceptual discrimination in autism (Cohen, 1994; Gustafsson, 1997); and to explore the emergence of disordered cortical feature maps using a neurobiologically constrained model (Oliver, Johnson, Karmiloff-Smith, & Pennington, in press). In this entry, we will examine the types of initial constraints that connectionist modelers typically build in to their models, and how variations in these constraints have been proposed as possible accounts of the causes of particular developmental disorders. In particular, we will examine the claim that these constraints are candidates for what will constitute innate knowledge. First, however, we need to consider a current debate concerning whether developmental disorders are a useful tool to explore the (possibly innate) structure of the normal cognitive system. We will find that connectionist approaches are much more consistent with one side of this debate than the other
The distribution of trimoraic syllables in German and English as evidence for the phonological word
In the present article I discuss the distribution of trimoraic syllables in German and English. The reason I have chosen to analyze these two languages together is that the data in both languages are strikingly similar. However, although the basic generalization in (1) holds for both German and English, we will see below that trimoraic syllabIes do not have an identical distribution in both languages.
In the present study I make the following theoretical claims. First, I argue that the three environments in (1) have a property in common: they all describe the right edge of a phonological word (or prosodic word; henceforth pword). From a formal point of view, I argue that a constraint I dub the THIRD MORA RESTRICTION (henceforth TMR), which ensures that trimoraic syllables surface at the end of a pword, is active in German and English. According to my proposal trimoraic syllables cannot occur morpheme-internally because monomorphemic grammatical words like garden are parsed as single pwords. Second, I argue that the TMR refers crucially to moraic structure. In particular, underlined strings like the ones in (1) will be shown to be trimoraic; neither skeletal positions nor the subsyllabic constituent rhyme are necessary. Third, the TMR will be shown to be violated in certain (predictable) pword-internal cases, as in Monde and chamber; I account for such facts in an OptimalityTheoretic analysis (henceforth OT; Prince & Smolensky 1993) by ranking various markedness constraints among themselves or by ranking them ahead of the TMR. Fourth, I hold that the TMR describes a concrete level of grammar, which I refer to below as the 'surface' representation. In this respect, my treatment differs significantly from the one proposed for English by Borowsky (1986, 1989), in which the English facts are captured in a Lexical Phonology model by ordering the relevant constraint at level 1 in the lexicon
TEST: A Tropic, Embodied, and Situated Theory of Cognition
TEST is a novel taxonomy of knowledge representations based on three distinct hierarchically organized representational features: Tropism, Embodiment, and Situatedness. Tropic representational features reflect constraints of the physical world on the agent’s ability to form, reactivate, and enrich embodied (i.e., resulting from the agent’s bodily constraints) conceptual representations embedded in situated contexts. The proposed hierarchy entails that representations can, in principle, have tropic features without necessarily having situated and/or embodied features. On the other hand, representations that are situated and/or embodied are likely to be simultaneously tropic. Hence while we propose tropism as the most general term, the hierarchical relationship between embodiment and situatedness is more on a par, such that the dominance of one component over the other relies on the distinction between offline storage vs. online generation as well as on representation-specific properties
Accidental matter at the LHC
We classify weak-scale extensions of the Standard Model which automatically
preserve its accidental and approximate symmetry structure at the
renormalizable level and which are hence invisible to low-energy indirect
probes. By requiring the consistency of the effective field theory up to scales
of 10^15 GeV and after applying cosmological constraints, we arrive at a finite
set of possibilities that we analyze in detail. One of the most striking
signatures of this framework is the presence of new charged and/or colored
states which can be efficiently produced in high-energy particle colliders and
which are stable on the scale of detectors.Comment: 55 pages, 13 figure
Walking in the SU(N)
We study the phase diagram as function of the number of colours and flavours
of asymptotically free non-supersymmetric theories with matter in higher
dimensional representations of arbitrary SU(N) gauge groups. Since matter in
higher dimensional representations screens more than in the fundamental a
general feature is that a lower number of flavours is needed to achieve a
near-conformal theory. We study the spectrum of the theories near the fixed
point and consider possible applications of our analysis to the dynamical
breaking of the electroweak symmetry.Comment: 12 page
Combining and Relating Control Effects and their Semantics
Combining local exceptions and first class continuations leads to programs
with complex control flow, as well as the possibility of expressing powerful
constructs such as resumable exceptions. We describe and compare games models
for a programming language which includes these features, as well as
higher-order references. They are obtained by contrasting methodologies: by
annotating sequences of moves with "control pointers" indicating where
exceptions are thrown and caught, and by composing the exceptions and
continuations monads.
The former approach allows an explicit representation of control flow in
games for exceptions, and hence a straightforward proof of definability (full
abstraction) by factorization, as well as offering the possibility of a
semantic approach to control flow analysis of exception-handling. However,
establishing soundness of such a concrete and complex model is a non-trivial
problem. It may be resolved by establishing a correspondence with the monad
semantics, based on erasing explicit exception moves and replacing them with
control pointers.Comment: In Proceedings COS 2013, arXiv:1309.092
- …