1,194 research outputs found
Learning Sequential Acquisition Policies for Robot-Assisted Feeding
A robot providing mealtime assistance must perform specialized maneuvers with
various utensils in order to pick up and feed a range of food items. Beyond
these dexterous low-level skills, an assistive robot must also plan these
strategies in sequence over a long horizon to clear a plate and complete a
meal. Previous methods in robot-assisted feeding introduce highly specialized
primitives for food handling without a means to compose them together.
Meanwhile, existing approaches to long-horizon manipulation lack the
flexibility to embed highly specialized primitives into their frameworks. We
propose Visual Action Planning OveR Sequences (VAPORS), a framework for
long-horizon food acquisition. VAPORS learns a policy for high-level action
selection by leveraging learned latent plate dynamics in simulation. To carry
out sequential plans in the real world, VAPORS delegates action execution to
visually parameterized primitives. We validate our approach on complex
real-world acquisition trials involving noodle acquisition and bimanual
scooping of jelly beans. Across 38 plates, VAPORS acquires much more
efficiently than baselines, generalizes across realistic plate variations such
as toppings and sauces, and qualitatively appeals to user feeding preferences
in a survey conducted across 49 individuals. Code, datasets, videos, and
supplementary materials can be found on our website:
https://sites.google.com/view/vaporsbot
Texture Generation on 3D Meshes with Point-UV Diffusion
In this work, we focus on synthesizing high-quality textures on 3D meshes. We
present Point-UV diffusion, a coarse-to-fine pipeline that marries the
denoising diffusion model with UV mapping to generate 3D consistent and
high-quality texture images in UV space. We start with introducing a point
diffusion model to synthesize low-frequency texture components with our
tailored style guidance to tackle the biased color distribution. The derived
coarse texture offers global consistency and serves as a condition for the
subsequent UV diffusion stage, aiding in regularizing the model to generate a
3D consistent UV texture image. Then, a UV diffusion model with hybrid
conditions is developed to enhance the texture fidelity in the 2D UV space. Our
method can process meshes of any genus, generating diversified,
geometry-compatible, and high-fidelity textures. Code is available at
https://cvmi-lab.github.io/Point-UV-DiffusionComment: Accepted to ICCV 2023, Ora
The Decomposition Theorem and the topology of algebraic maps
We give a motivated introduction to the theory of perverse sheaves,
culminating in the Decomposition Theorem of Beilinson, Bernstein, Deligne and
Gabber. A goal of this survey is to show how the theory develops naturally from
classical constructions used in the study of topological properties of
algebraic varieties. While most proofs are omitted, we discuss several
approaches to the Decomposition Theorem, indicate some important applications
and examples.Comment: 117 pages. New title. Major structure changes. Final version of a
survey to appear in the Bulletin of the AM
Period Integrals of CY and General Type Complete Intersections
We develop a global Poincar\'e residue formula to study period integrals of
families of complex manifolds. For any compact complex manifold equipped
with a linear system of generically smooth CY hypersurfaces, the formula
expresses period integrals in terms of a canonical global meromorphic top form
on . Two important ingredients of our construction are the notion of a CY
principal bundle, and a classification of such rank one bundles. We also
generalize our construction to CY and general type complete intersections. When
is an algebraic manifold having a sufficiently large automorphism group
and is a linear representation of , we construct a holonomic D-module
that governs the period integrals. The construction is based in part on the
theory of tautological systems we have developed in the paper \cite{LSY1},
joint with R. Song. The approach allows us to explicitly describe a
Picard-Fuchs type system for complete intersection varieties of general types,
as well as CY, in any Fano variety, and in a homogeneous space in particular.
In addition, the approach provides a new perspective of old examples such as CY
complete intersections in a toric variety or partial flag variety.Comment: An erratum is included to correct Theorem 3.12 (Uniqueness of CY
structure
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