786 research outputs found
Regulatory B Cells in Experimental Mouse Models of Arthritis
Regulatory B cells (Breg) have been shown to have a role in the suppression of a wide variety of immune responses, yet they are deficient or defective in autoimmune diseases such as rheumatoid arthritis. For the study of autoimmune inflammation, experimental models of arthritis have acted as a valuable tool in understanding the development of Bregs and their role in maintaining immune homeostasis. In this chapter, we will focus on the study of transitional-2 marginal zone precursor (T2-MZP) Bregs in the context of two experimental arthritis models: antigen-induced arthritis (AIA) and collagen-induced arthritis (CIA). We will specifically focus on how to induce arthritis, as well as on methods for the isolation and functional study of Bregs both in vitro and in vivo
2D Density Control of Micro-Particles using Kernel Density Estimation
We address the problem of 2D particle density control. The particles are
immersed in dielectric fluid and acted upon by manipulating an electric field.
The electric field is controlled by an array of electrodes and used to bring
the particle density to a desired pattern using dielectrophoretic forces. We
use a lumped, 2D, capacitive-based, nonlinear model describing the motion of a
particle. The spatial dependency of the capacitances is estimated using
electrostatic COMSOL simulations. We formulate an optimal control problem,
where the loss function is defined in terms of the error between the particle
density at some final time and a target density. We use a kernel density
estimator (KDE) as a proxy for the true particle density. The KDE is computed
using the particle positions that are changed by varying the electrode
potentials. We showcase our approach through numerical simulations, where we
demonstrate how the particle positions and the electrode potentials vary when
shaping the particle positions from a uniform to a Gaussian distribution
L'arithmétique sur le tas
National audienceOn appelle un tas de bits une somme non évaluée de variable binaires, chacune pondérée par une puissance de 2. Par exemple, tous les polynômes à plusieurs variables peuvent s'exprimer comme un tas dont chaque variable est un ET logique des bits d'entrée. Cette représentation est pertinente car elle exprime le parallélisme au niveau du bit. La littérature sur les multiplieurs binaires montre comment construire des architectures efficaces qui calculent la valeurd'un tas de bits. Le présent article montre l'intérêt de revisiter un certain nombre d'opérateurs arithmétiques composés pour les exprimer comme des tas de bits
AI Enhanced Control Engineering Methods
AI and machine learning based approaches are becoming ubiquitous in almost
all engineering fields. Control engineering cannot escape this trend. In this
paper, we explore how AI tools can be useful in control applications. The core
tool we focus on is automatic differentiation. Two immediate applications are
linearization of system dynamics for local stability analysis or for state
estimation using Kalman filters. We also explore other usages such as
conversion of differential algebraic equations to ordinary differential
equations for control design. In addition, we explore the use of machine
learning models for global parameterizations of state vectors and control
inputs in model predictive control applications. For each considered use case,
we give examples and results
An optimization-based approach to automated design
We propose a model-based, automated, bottom-up approach for design, which is
applicable to various physical domains, but in this work we focus on the
electrical domain. This bottom-up approach is based on a meta-topology in which
each link is described by a universal component that can be instantiated as
basic components (e.g., resistors, capacitors) or combinations of basic
components via discrete switches. To address the combinatorial explosion often
present in mixed-integer optimization problems, we present two algorithms. In
the first algorithm, we convert the discrete switches into continuous switches
that are physically realizable and formulate a parameter optimization problem
that learns the component and switch parameters while inducing design sparsity
through an regularization term. The second algorithm uses a genetic-like
approach with selection and mutation steps guided by ranking of requirements
costs, combined with continuous optimization for generating optimal parameters.
We improve the time complexity of the optimization problem in both algorithms
by reconstructing the model when components become redundant and by simplifying
topologies through collapsing components and removing disconnected ones. To
demonstrate the efficacy of these algorithms, we apply them to the design of
various electrical circuits
On Balance: Intelligence Democratization in Post-Franco Spain
The article of record as published may be found at http://dx.doi.org/10.1080/08850607.2018.146658
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