Search results for "Invariant"
showing 10 items of 783 documents
Analysis of Invariant Chain Processing in 3 Day Cultured Rat Langerhans Cells
1995
MHC class II molecules, critical peptide binding elements involved in the presentation of exogenous antigen to T helper cells, are expressed constitutively by Langerhans cells (LC) within their epidermal microenvironment. Several studies in mouse and man demonstrated, that short term in vitro culture of LC entails remarkable functional and penotypic alterations, including a profound increase of class II elements exposed at the LC’s surface1. Biosynthetic analysis revealed a downregulation of class II synthesis during the culture period2,3. In recent work on rat LC we described the uncoupling of the coordinately regulated biosynthesis of class II and invariant chain proteins in the course of…
Shift-Invariant Canonical Polyadic Decomposition of Complex-Valued Multi-Subject fMRI Data with a Phase Sparsity Constraint
2020
Canonical polyadic decomposition (CPD) of multi-subject complex-valued fMRI data can be used to provide spatially and temporally shared components among groups with both magnitude and phase information. However, the CPD model is not well formulated due to the large subject variability in the spatial and temporal modalities, as well as the high noise level in complex-valued fMRI data. Considering that the shift-invariant CPD can model temporal variability across subjects, we propose to further impose a phase sparsity constraint on the shared spatial maps to denoise the complex-valued components and to model the inter-subject spatial variability as well. More precisely, subject-specific time …
Belief, acceptance and knowledge
2009
According to Contextualism about knowledge, it is possible that a subject, with the same amount of evidence and the same degree of con-viction, knows that P in a context and not in another. In this paper, I favor the invarationist conception of knowledge by drawing a distinction between belief and acceptance."Know", I defend, does not change in meaning across contexts, althoughI acknowledge it is not correct to self ascribe knowledge when one does not accept that P. Según la posición contextualista puede ocurrir que con las mis-mas evidencias y el mismo grado de convicción, un sujeto sepa que P en un contexto y no en otro. Mediante la distinción entre aceptación y creencia, se combate tal p…
Predictive control of convex polyhedron LPV systems with Markov jumping parameters
2012
The problem of receding horizon predictive control of stochastic linear parameter varying systems is discussed. First, constant coefficient matrices are obtained at each vertex in the interior of linear parameter varying system, and then, by considering semi-definite programming constraints, weight coefficients between each vertex are calculated, and the equal coefficients matrices for the time variable system are obtained. Second, in the given receding horizon, for each mode sequence of the stochastic convex polyhedron linear parameter varying systems, the optimal control input sequences are designed in order to make the states into a terminal invariant set. Outside of the receding horizon…
A note on the existence of an invariant measure for a stochastic model with periodic coefficients
2012
We consider a stochastic model of malaria which concern the infected population and the vector population and whose coefficients are periodic functions. Under a suitable condition the existence of an invariant measure is proved.
Defining relations of minimal degree of the trace algebra of 3 X 3 matrices
2008
The trace algebra Cnd over a field of characteristic 0 is generated by all traces of products of d generic n × n matrices, n, d 2. Minimal sets of generators of Cnd are known for n = 2 and n = 3 for any d as well as for n = 4 and n = 5 and d = 2. The defining relations between the generators are found for n = 2 and any d and for n = 3, d = 2 only. Starting with the generating set of C3d given by Abeasis and Pittaluga in 1989, we have shown that the minimal degree of the set of defining relations of C3d is equal to 7 for any d 3. We have determined all relations of minimal degree. For d = 3 we have also found the defining relations of degree 8. The proofs are based on methods of representati…
Mesure invariante d'une equation integrale stochastique a coefficients periodiques et applications a un modele d'epidemiologie
2012
We consider a stochastic integral equation, whose coe cients are periodic in time. Under a suitable condition we prove the existence of an invariant mesure for this stochastic equation. This invariant mesure is constructed on a Banach space of continuous functions. We study also its application to an epidemiologic model of malaria, which concerns the infected population and the vector population.
Jet mass and substructure of inclusive jets in $ \sqrt {s} = 7\;{\text{TeV}} $ pp collisions with the ATLAS experiment
2012
Recent studies have highlighted the potential of jet substructure techniques to identify the hadronic decays of boosted heavy particles. These studies all rely upon the assumption that the internal substructure of jets generated by QCD radiation is well understood. In this article, this assumption is tested on an inclusive sample of jets recorded with the ATLAS detector in 2010, which corresponds to 35 pb-1 of pp collisions delivered by the LHC at √s = 7TeV. In a subsample of events with single pp collisions, measurements corrected for detector efficiency and resolution are presented with full systematic uncertainties. Jet invariant mass, kt splitting scales and N-subjettiness variables are…
Voisinages tubulaires épointés et homotopie stable à l'infini
2022
We initiate a study of punctured tubular neighborhoods and homotopy theory at infinity in motivic settings. We use the six functors formalism to give an intrinsic definition of the stable motivic homotopy type at infinity of an algebraic variety. Our main computational tools include cdh-descent for normal crossing divisors, Euler classes, Gysin maps, and homotopy purity. Under-adic realization, the motive at infinity recovers a formula for vanishing cycles due to Rapoport-Zink; similar results hold for Steenbrink's limiting Hodge structures and Wildeshaus' boundary motives. Under the topological Betti realization, the stable motivic homotopy type at infinity of an algebraic variety recovers…
SIFT Texture Description for Understanding Breast Ultrasound Images
2014
Texture is a powerful cue for describing structures that show a high degree of similarity in their image intensity patterns. This paper describes the use of Self-Invariant Feature Transform (SIFT), both as low-level and high-level descriptors, applied to differentiate the tissues present in breast US images. For the low-level texture descriptors case, SIFT descriptors are extracted from a regular grid. The high-level texture descriptor is build as a Bag-of-Features (BoF) of SIFT descriptors. Experimental results are provided showing the validity of the proposed approach for describing the tissues in breast US images.