1,363 research outputs found
Some New Light-cone Time Dependent Solutions in Deformed pp-wave Backgrounds
Brane solutions in time \ light-cone time dependent backgrounds are of
interest in order to gain a deeper understanding of the physics associated with
cosmological and null singularities. In this paper, we report both brane
solutions and their bound states in light-cone time dependent pp wave-like
backgrounds. We show that the backgrounds our solutions live in are all
cosmologically singular (lightlike) at the classical level. A spacetime
supersymmetry analysis of the backgrounds reveals that they retain 1/8 of the
full type IIB supersymmetry
Empirical Bounds on Linear Regions of Deep Rectifier Networks
We can compare the expressiveness of neural networks that use rectified
linear units (ReLUs) by the number of linear regions, which reflect the number
of pieces of the piecewise linear functions modeled by such networks. However,
enumerating these regions is prohibitive and the known analytical bounds are
identical for networks with same dimensions. In this work, we approximate the
number of linear regions through empirical bounds based on features of the
trained network and probabilistic inference. Our first contribution is a method
to sample the activation patterns defined by ReLUs using universal hash
functions. This method is based on a Mixed-Integer Linear Programming (MILP)
formulation of the network and an algorithm for probabilistic lower bounds of
MILP solution sets that we call MIPBound, which is considerably faster than
exact counting and reaches values in similar orders of magnitude. Our second
contribution is a tighter activation-based bound for the maximum number of
linear regions, which is particularly stronger in networks with narrow layers.
Combined, these bounds yield a fast proxy for the number of linear regions of a
deep neural network.Comment: AAAI 202
An Inventory of Preposition Relations
We describe an inventory of semantic relations that are expressed by
prepositions. We define these relations by building on the word sense
disambiguation task for prepositions and propose a mapping from preposition
senses to the relation labels by collapsing semantically related senses across
prepositions.Comment: Supplementary material for Srikumar and Roth, 2013. Modeling Semantic
Relations Expressed by Prepositions, TAC
A Taxonomy of Data Grids for Distributed Data Sharing, Management and Processing
Data Grids have been adopted as the platform for scientific communities that
need to share, access, transport, process and manage large data collections
distributed worldwide. They combine high-end computing technologies with
high-performance networking and wide-area storage management techniques. In
this paper, we discuss the key concepts behind Data Grids and compare them with
other data sharing and distribution paradigms such as content delivery
networks, peer-to-peer networks and distributed databases. We then provide
comprehensive taxonomies that cover various aspects of architecture, data
transportation, data replication and resource allocation and scheduling.
Finally, we map the proposed taxonomy to various Data Grid systems not only to
validate the taxonomy but also to identify areas for future exploration.
Through this taxonomy, we aim to categorise existing systems to better
understand their goals and their methodology. This would help evaluate their
applicability for solving similar problems. This taxonomy also provides a "gap
analysis" of this area through which researchers can potentially identify new
issues for investigation. Finally, we hope that the proposed taxonomy and
mapping also helps to provide an easy way for new practitioners to understand
this complex area of research.Comment: 46 pages, 16 figures, Technical Repor
- …