147,607 research outputs found
PivotNet: Vectorized Pivot Learning for End-to-end HD Map Construction
Vectorized high-definition map online construction has garnered considerable
attention in the field of autonomous driving research. Most existing approaches
model changeable map elements using a fixed number of points, or predict local
maps in a two-stage autoregressive manner, which may miss essential details and
lead to error accumulation. Towards precise map element learning, we propose a
simple yet effective architecture named PivotNet, which adopts unified
pivot-based map representations and is formulated as a direct set prediction
paradigm. Concretely, we first propose a novel point-to-line mask module to
encode both the subordinate and geometrical point-line priors in the network.
Then, a well-designed pivot dynamic matching module is proposed to model the
topology in dynamic point sequences by introducing the concept of sequence
matching. Furthermore, to supervise the position and topology of the vectorized
point predictions, we propose a dynamic vectorized sequence loss. Extensive
experiments and ablations show that PivotNet is remarkably superior to other
SOTAs by 5.9 mAP at least. The code will be available soon.Comment: Accepted by ICCV202
R2O, an extensible and semantically based database-to-ontology mapping language
We present R2O, an extensible and declarative language to describe mappings between relational DB schemas and ontologies implemented in RDF(S) or OWL. R2O provides an extensible set of primitives with welldefined semantics. This language has been conceived expressive enough to cope with complex mapping cases arisen from situations of low similarity between the ontology and the DB models
Noetherianity for infinite-dimensional toric varieties
We consider a large class of monomial maps respecting an action of the
infinite symmetric group, and prove that the toric ideals arising as their
kernels are finitely generated up to symmetry. Our class includes many
important examples where Noetherianity was recently proved or conjectured. In
particular, our results imply Hillar-Sullivant's Independent Set Theorem and
settle several finiteness conjectures due to Aschenbrenner, Martin del Campo,
Hillar, and Sullivant.
We introduce a matching monoid and show that its monoid ring is Noetherian up
to symmetry. Our approach is then to factorize a more general equivariant
monomial map into two parts going through this monoid. The kernels of both
parts are finitely generated up to symmetry: recent work by
Yamaguchi-Ogawa-Takemura on the (generalized) Birkhoff model provides an
explicit degree bound for the kernel of the first part, while for the second
part the finiteness follows from the Noetherianity of the matching monoid ring.Comment: 20 page
Model Reduction by Moment Matching for Linear Switched Systems
Two moment-matching methods for model reduction of linear switched systems
(LSSs) are presented. The methods are similar to the Krylov subspace methods
used for moment matching for linear systems. The more general one of the two
methods, is based on the so called "nice selection" of some vectors in the
reachability or observability space of the LSS. The underlying theory is
closely related to the (partial) realization theory of LSSs. In this paper, the
connection of the methods to the realization theory of LSSs is provided, and
algorithms are developed for the purpose of model reduction. Conditions for
applicability of the methods for model reduction are stated and finally the
results are illustrated on numerical examples.Comment: Sent for publication in IEEE TAC, on October 201
The C++0x "Concepts" Effort
C++0x is the working title for the revision of the ISO standard of the C++
programming language that was originally planned for release in 2009 but that
was delayed to 2011. The largest language extension in C++0x was "concepts",
that is, a collection of features for constraining template parameters. In
September of 2008, the C++ standards committee voted the concepts extension
into C++0x, but then in July of 2009, the committee voted the concepts
extension back out of C++0x.
This article is my account of the technical challenges and debates within the
"concepts" effort in the years 2003 to 2009. To provide some background, the
article also describes the design space for constrained parametric
polymorphism, or what is colloquially know as constrained generics. While this
article is meant to be generally accessible, the writing is aimed toward
readers with background in functional programming and programming language
theory. This article grew out of a lecture at the Spring School on Generic and
Indexed Programming at the University of Oxford, March 2010
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