548,262 research outputs found
Recognizing Rigid Patterns of Unlabeled Point Clouds by Complete and Continuous Isometry Invariants with no False Negatives and no False Positives
Rigid structures such as cars or any other solid objects are often
represented by finite clouds of unlabeled points. The most natural equivalence
on these point clouds is rigid motion or isometry maintaining all inter-point
distances. Rigid patterns of point clouds can be reliably compared only by
complete isometry invariants that can also be called equivariant descriptors
without false negatives (isometric clouds having different descriptions) and
without false positives (non-isometric clouds with the same description). Noise
and motion in data motivate a search for invariants that are continuous under
perturbations of points in a suitable metric. We propose the first continuous
and complete invariant of unlabeled clouds in any Euclidean space. For a fixed
dimension, the new metric for this invariant is computable in a polynomial time
in the number of points.Comment: This conference version is for CVPR (Computer Vision and Pattern
Recognition), https://cvpr2023.thecvf.com. The latest file is
http://kurlin.org/projects/cloud-isometry-spaces/distance-based-invariants.pdf.
The extended versions of sections 3-4 with all proofs and big examples are at
arXiv:2303.14161 for metric spaces, arXiv:2303.13486 for Euclidean spaces.
arXiv admin note: substantial text overlap with arXiv:2303.13486,
arXiv:2303.1416
Big data and the SP theory of intelligence
This article is about how the "SP theory of intelligence" and its realisation
in the "SP machine" may, with advantage, be applied to the management and
analysis of big data. The SP system -- introduced in the article and fully
described elsewhere -- may help to overcome the problem of variety in big data:
it has potential as "a universal framework for the representation and
processing of diverse kinds of knowledge" (UFK), helping to reduce the
diversity of formalisms and formats for knowledge and the different ways in
which they are processed. It has strengths in the unsupervised learning or
discovery of structure in data, in pattern recognition, in the parsing and
production of natural language, in several kinds of reasoning, and more. It
lends itself to the analysis of streaming data, helping to overcome the problem
of velocity in big data. Central in the workings of the system is lossless
compression of information: making big data smaller and reducing problems of
storage and management. There is potential for substantial economies in the
transmission of data, for big cuts in the use of energy in computing, for
faster processing, and for smaller and lighter computers. The system provides a
handle on the problem of veracity in big data, with potential to assist in the
management of errors and uncertainties in data. It lends itself to the
visualisation of knowledge structures and inferential processes. A
high-parallel, open-source version of the SP machine would provide a means for
researchers everywhere to explore what can be done with the system and to
create new versions of it.Comment: Accepted for publication in IEEE Acces
Designing algorithms to aid discovery by chemical robots
Recently, automated robotic systems have become very efficient, thanks to improved coupling between sensor systems and algorithms, of which the latter have been gaining significance thanks to the increase in computing power over the past few decades. However, intelligent automated chemistry platforms for discovery orientated tasks need to be able to cope with the unknown, which is a profoundly hard problem. In this Outlook, we describe how recent advances in the design and application of algorithms, coupled with the increased amount of chemical data available, and automation and control systems may allow more productive chemical research and the development of chemical robots able to target discovery. This is shown through examples of workflow and data processing with automation and control, and through the use of both well-used and cutting-edge algorithms illustrated using recent studies in chemistry. Finally, several algorithms are presented in relation to chemical robots and chemical intelligence for knowledge discovery
Strategies for Searching Video Content with Text Queries or Video Examples
The large number of user-generated videos uploaded on to the Internet
everyday has led to many commercial video search engines, which mainly rely on
text metadata for search. However, metadata is often lacking for user-generated
videos, thus these videos are unsearchable by current search engines.
Therefore, content-based video retrieval (CBVR) tackles this metadata-scarcity
problem by directly analyzing the visual and audio streams of each video. CBVR
encompasses multiple research topics, including low-level feature design,
feature fusion, semantic detector training and video search/reranking. We
present novel strategies in these topics to enhance CBVR in both accuracy and
speed under different query inputs, including pure textual queries and query by
video examples. Our proposed strategies have been incorporated into our
submission for the TRECVID 2014 Multimedia Event Detection evaluation, where
our system outperformed other submissions in both text queries and video
example queries, thus demonstrating the effectiveness of our proposed
approaches
CMB B-modes, spinorial space-time and Pre-Big Bang (II)
The BICEP2 collaboration reported recently a B-mode polarization of the
cosmic microwave background (CMB) radiation inconsistent with the null
hypothesis at a significance of > 5 {\sigma}. This result has been often
interpreted as a signature of primordial gravitational waves from cosmic
inflation, even if actually polarized dust emission may be at the origin of
such a signal. Even assuming that part of this CMB B-mode polarization really
corresponds to the early Universe dynamics, its interpretation in terms of
inflation and primordial gravitational waves is not the only possible one.
Alternative cosmologies such as pre-Big Bang patterns and the spinorial
space-time (SST) we introduced in 1996-97 can naturally account for such CMB
B-modes. In particular, the SST automatically generates a privileged space
direction (PSD) whose existence may have been confirmed by Planck data. If such
a PSD exists, it seems normal to infer that vector perturbations have been
present in the early Universe leading to CMB B-modes in suitable cosmological
patterns. Inflation would not be required to explain the BICEP2 result assuming
it really contains a primordial signal. More generally, pre-Big Bang
cosmologies can also generate gravitational waves in the early Universe without
any need for cosmic inflation. We further discuss here possible alternatives to
the inflationary interpretation of a primordial B-mode polarization of cosmic
microwave background radiation.Comment: 11 page
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