24,911 research outputs found
Strings from Logic
What are strings made of? The possibility is discussed that strings are
purely mathematical objects, made of logical axioms. More precisely, proofs in
simple logical calculi are represented by graphs that can be interpreted as the
Feynman diagrams of certain large-N field theories. Each vertex represents an
axiom. Strings arise, because these large-N theories are dual to string
theories. These ``logical quantum field theories'' map theorems into the space
of functions of two parameters: N and the coupling constant. Undecidable
theorems might be related to nonperturbative field theory effects.Comment: Talk, 19 pp, 7 figure
SCAN: Learning Hierarchical Compositional Visual Concepts
The seemingly infinite diversity of the natural world arises from a
relatively small set of coherent rules, such as the laws of physics or
chemistry. We conjecture that these rules give rise to regularities that can be
discovered through primarily unsupervised experiences and represented as
abstract concepts. If such representations are compositional and hierarchical,
they can be recombined into an exponentially large set of new concepts. This
paper describes SCAN (Symbol-Concept Association Network), a new framework for
learning such abstractions in the visual domain. SCAN learns concepts through
fast symbol association, grounding them in disentangled visual primitives that
are discovered in an unsupervised manner. Unlike state of the art multimodal
generative model baselines, our approach requires very few pairings between
symbols and images and makes no assumptions about the form of symbol
representations. Once trained, SCAN is capable of multimodal bi-directional
inference, generating a diverse set of image samples from symbolic descriptions
and vice versa. It also allows for traversal and manipulation of the implicit
hierarchy of visual concepts through symbolic instructions and learnt logical
recombination operations. Such manipulations enable SCAN to break away from its
training data distribution and imagine novel visual concepts through
symbolically instructed recombination of previously learnt concepts
The Living Gesture and the Signifying Moment
Drawing from Peircean semiotics, from the Greek conception of phronesis, and from considerations of bodily awareness as a basis of reasonableness, I attempt to show how the living gesture touches our deepest signifying nature, the self, and public life. Gestural bodily awareness, more than knowledge, connects us with the very conditions out of which the human body evolved into its present condition and remains a vital resource in the face of a devitalizing, rationalistic consumption culture. It may be precisely these deep-rooted abilities for what I term âself-originated experienceâ that can ultimately offset automatism
SDEs Driven by SDE Solutions
We consider stochastic differential equations (SDEs) driven by Feller
processes which are themselves solutions of multivariate Levy driven SDEs. The
solutions of these 'iterated SDEs' are shown to be non-Markovian. However, the
process consisting of the driving process and the solution is Markov and even
Feller in the case of bounded coefficients. The generator as well as the
semimartingale characteristics of this process are calculated explicitly and
fine properties of the solution are derived via the stochastic symbol. A short
simulation study and an outlook in the direction of stochastic modeling round
out the paper.Comment: 16 pages, 9 figure
Lexical and Derivational Meaning in Vector-Based Models of Relativisation
Sadrzadeh et al (2013) present a compositional distributional analysis of
relative clauses in English in terms of the Frobenius algebraic structure of
finite dimensional vector spaces. The analysis relies on distinct type
assignments and lexical recipes for subject vs object relativisation. The
situation for Dutch is different: because of the verb final nature of Dutch,
relative clauses are ambiguous between a subject vs object relativisation
reading. Using an extended version of Lambek calculus, we present a
compositional distributional framework that accounts for this derivational
ambiguity, and that allows us to give a single meaning recipe for the relative
pronoun reconciling the Frobenius semantics with the demands of Dutch
derivational syntax.Comment: 10 page version to appear in Proceedings Amsterdam Colloquium,
updated with appendi
Neural Mechanisms for Information Compression by Multiple Alignment, Unification and Search
This article describes how an abstract framework for perception and cognition may be realised in terms of neural mechanisms and neural processing.
This framework â called information compression by multiple alignment, unification and search (ICMAUS) â has been developed in previous research as a generalized model of any system for processing information, either natural or
artificial. It has a range of applications including the analysis and production of natural language, unsupervised inductive learning, recognition of objects and patterns, probabilistic reasoning, and others. The proposals in this article may be seen as an extension and development of
Hebbâs (1949) concept of a âcell assemblyâ.
The article describes how the concept of âpatternâ in the ICMAUS framework may be mapped onto a version of the cell
assembly concept and the way in which neural mechanisms may achieve the effect of âmultiple alignmentâ in the ICMAUS framework.
By contrast with the Hebbian concept of a cell assembly, it is proposed here that any one neuron can belong in one assembly and only one assembly. A key feature of present proposals, which is not part of the Hebbian concept, is that any cell assembly may contain âreferencesâ or âcodesâ that serve to identify one or more other cell assemblies. This mechanism allows information to be stored in a compressed form, it provides a robust mechanism by which assemblies may be connected to form hierarchies and other kinds of structure, it means that assemblies can express
abstract concepts, and it provides solutions to some of the other problems associated with cell assemblies.
Drawing on insights derived from the ICMAUS framework, the article also describes how learning may be achieved with neural mechanisms. This concept of learning is significantly different from the Hebbian concept and appears to provide a better account of what we know about human learning
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