3,075 research outputs found
Modular Design Patterns for Hybrid Learning and Reasoning Systems: a taxonomy, patterns and use cases
The unification of statistical (data-driven) and symbolic (knowledge-driven)
methods is widely recognised as one of the key challenges of modern AI. Recent
years have seen large number of publications on such hybrid neuro-symbolic AI
systems. That rapidly growing literature is highly diverse and mostly
empirical, and is lacking a unifying view of the large variety of these hybrid
systems. In this paper we analyse a large body of recent literature and we
propose a set of modular design patterns for such hybrid, neuro-symbolic
systems. We are able to describe the architecture of a very large number of
hybrid systems by composing only a small set of elementary patterns as building
blocks.
The main contributions of this paper are: 1) a taxonomically organised
vocabulary to describe both processes and data structures used in hybrid
systems; 2) a set of 15+ design patterns for hybrid AI systems, organised in a
set of elementary patterns and a set of compositional patterns; 3) an
application of these design patterns in two realistic use-cases for hybrid AI
systems. Our patterns reveal similarities between systems that were not
recognised until now. Finally, our design patterns extend and refine Kautz'
earlier attempt at categorising neuro-symbolic architectures.Comment: 20 pages, 22 figures, accepted for publication in the International
Journal of Applied Intelligenc
Explanation Techniques using Markov Logic Networks
Explanation Techniques using Markov Logic Network
LASER: A Neuro-Symbolic Framework for Learning Spatial-Temporal Scene Graphs with Weak Supervision
We propose LASER, a neuro-symbolic approach to learn semantic video
representations that capture rich spatial and temporal properties in video data
by leveraging high-level logic specifications. In particular, we formulate the
problem in terms of alignment between raw videos and spatio-temporal logic
specifications. The alignment algorithm leverages a differentiable symbolic
reasoner and a combination of contrastive, temporal, and semantics losses. It
effectively and efficiently trains low-level perception models to extract
fine-grained video representation in the form of a spatio-temporal scene graph
that conforms to the desired high-level specification. In doing so, we explore
a novel methodology that weakly supervises the learning of video semantic
representations through logic specifications. We evaluate our method on two
datasets with rich spatial and temporal specifications:
20BN-Something-Something and MUGEN. We demonstrate that our method learns
better fine-grained video semantics than existing baselines
Classical Vs Quantum Probability in Sequential Measurements
We demonstrate in this paper that the probabilities for sequential
measurements have features very different from those of single-time
measurements. First, they cannot be modelled by a classical stochastic process.
Second, they are contextual, namely they depend strongly on the specific
measurement scheme through which they are determined. We construct
Positive-Operator-Valued measures (POVM) that provide such probabilities. For
observables with continuous spectrum, the constructed POVMs depend strongly on
the resolution of the measurement device, a conclusion that persists even if we
consider a quantum mechanical measurement device or the presence of an
environment. We then examine the same issues in alternative interpretations of
quantum theory. We first show that multi-time probabilities cannot be naturally
defined in terms of a frequency operator. We next prove that local hidden
variable theories cannot reproduce the predictions of quantum theory for
sequential measurements, even when the degrees of freedom of the measuring
apparatus are taken into account. Bohmian mechanics, however, does not fall in
this category. We finally examine an alternative proposal that sequential
measurements can be modelled by a process that does not satisfy the Kolmogorov
axioms of probability. This removes contextuality without introducing
non-locality, but implies that the empirical probabilities cannot be always
defined (the event frequencies do not converge). We argue that the predictions
of this hypothesis are not ruled out by existing experimental results
(examining in particular the "which way" experiments); they are, however,
distinguishable in principle.Comment: 56 pages, latex; revised and restructured. Version to appear in
Found. Phy
Interdependent policy instrument preferences: a two-mode network approach
In policymaking, actors are likely to take the preferences of others into account when strategically positioning themselves. However, there is a lack of research that conceives of policy preferences as an interdependent system. In order to analyse interdependencies, we link actors to their policy preferences in water protection, which results in an actor-instrument network. As actors exhibit multiple preferences, a complex two-mode network between actors and policies emerges. We analyse whether actors exhibit interdependent preference profiles given shared policy objectives or social interactions among them. By fitting an exponential random graph model to the actor-instrument network, we find considerable clustering, meaning that actors tend to exhibit preferences for multiple policy instruments in common. Actors tend to exhibit interdependent policy preferences when they are interconnected, that is, they collaborate with each other. By contrast, actors are less likely to share policy preferences when a conflict line divides them
A new proposal how to handle counterexamples to Markov causation à la Cartwright, or: fixing the chemical factory
Cartwright (Synthese 121(1/2):3-27, 1999a; The dappled world, Cambridge University Press, Cambridge, 1999b) attacked the view that causal relations conform to the Markov condition by providing a counterexample in which a common cause does not screen off its effects: the prominent chemical factory. In this paper we suggest a new way to handle counterexamples to Markov causation such as the chemical factory. We argue that Cartwright's as well as similar scenarios (such as decay processes, EPR/B experiments, or spontaneous macro breaking processes) feature a certain kind of non-causal dependence that kicks in once the common cause occurs. We then develop a representation of this specific kind of non-causal dependence that allows for modeling the problematic scenarios in such a way that the Markov condition is not violated anymore
- …