4,654 research outputs found
The full Schwinger-Dyson tower for random tensor models
We treat random rank- tensor models as -dimensional quantum field
theories---tensor field theories (TFT)---and review some of their
non-perturbative methods. We classify the correlation functions of complex
tensor field theories by boundary graphs, sketch the derivation of the
Ward-Takahashi identity and stress its relevance in the derivation of the tower
of exact, analytic Schwinger-Dyson equations for all the correlation functions
(with connected boundary) of TFTs with quartic pillow-like interactions.Comment: Proceedings: Corfu 2017 Training School "Quantum Spacetime and
Physics Models
Computing the spectral action for fuzzy geometries: from random noncommutative geometry to bi-tracial multimatrix models
A fuzzy geometry is a certain type of spectral triple whose Dirac operator
crucially turns out to be a finite matrix. This notion was introduced in [J.
Barrett, J. Math. Phys. 56, 082301 (2015)] and accommodates familiar fuzzy
spaces like spheres and tori. In the framework of random noncommutative
geometry, we use Barrett's characterization of Dirac operators of fuzzy
geometries in order to systematically compute the spectral action for -dimensional fuzzy geometries. In contrast to the
original Chamseddine-Connes spectral action, we take a polynomial with
as in order to obtain a well-defined path
integral that can be stated as a random matrix model with action of the type
, being and noncommutative polynomials in
complex matrices that parametrize the Dirac operator
. For arbitrary signature---thus for any admissible KO-dimension---formulas
for 2-dimensional fuzzy geometries are given up to a sextic polynomial, and up
to a quartic polynomial for 4-dimensional ones, with focus on the octo-matrix
models for Lorentzian and Riemannian signatures. The noncommutative polynomials
and are obtained via chord diagrams and satisfy: independence of
; self-adjointness of the main polynomial (modulo cyclic reordering of
each monomial); also up to cyclicity, either self-adjointness or
anti-self-adjointness of and simultaneously, for fixed .
Collectively, this favors a free probabilistic perspective for the large-
limit we elaborate on.Comment: 51 pages (45+6), some figures. v5. Minor amend to Prop. 4.1 and
syntax of Def. 2.
Management System for Harvest Scheduling: The Case of Horticultural Production in Southeast Spain
horticultural farmer, optimization, planning, mathematical programming, marketing, cooperative, Agribusiness, Crop Production/Industries, Demand and Price Analysis, Farm Management, Land Economics/Use,
Amistades, beneficios y contactos. Las dinámicas políticas en el estado de Puebla, 1993-2020
"En el presente trabajo se estudiará el cacicazgo avilacamachista en Puebla, particularmente el caso del Gral. Maximino Ávila Camacho, como una forma de liderazgo determinante del éxito o fracaso de un dirigente político. La investigación tiene como objetivo proponer el tema del cacicazgo como un auxiliar que permita analizar la realidad política de Puebla y contribuir a una mejor conducta en este fino y severo arte de lo político, sino también lograr una mejor toma de decisiones en diversos rubros al no estar pensada la tesis solo con fines electorales, si se quiere poner un ejemplo, sino acorde a las reales vicisitudes por las que atraviesa el entorno mexicano y poblano. Es por ello que la tesis será en manos del buen lector una herramienta de identificación de la línea política de la que proviene aquel o aquellos actores políticos que tenga enfrente, sino también una guía para saber cuáles son los caminos a seguir para visualizar sus objetivos y móviles"
The segments method
Se reporta el uso de segmentos como dominio de integración para los métodos libres de mallas de tipo Petrov-Galerkin Local (MLPG). El procedimiento acarrea ventajas en el tratamiento de dominios con forma geométrica irregular, circunda el problema de la precisión numérica en la cuadratura y permite de forma simple traspasar un número arbitrario de derivadas de la función de forma a la función de ponderación. Este
trabajo describe el procedimiento algebraico necesario. Además hace referencia al estudio experimental de errores que se hizo para el presente método en casos de prueba bidimensionales; con el objetivo de constatar
la estabilidad y precisión del mismo.Peer Reviewe
Low-Cost Piezoelectric Sensors for Time Domain Load Monitoring of Metallic Structures During Operational and Maintenance Processes
The versatility of piezoelectric sensors in measurement techniques and their performance in applications has given rise to an increased interest in their use for structural and manufacturing component monitoring. They enable wireless and sensor network solutions to be developed in order to directly integrate the sensors into machines, fixtures and tools. Piezoelectric sensors increasingly compete with strain-gauges due to their wide operational temperature range, load and strain sensing accuracy, low power consumption and low cost. This research sets out the use of piezoelectric sensors for real-time monitoring of mechanical strength in metallic structures in the ongoing operational control of machinery components. The behaviour of aluminium and steel structures under flexural strength was studied using piezoelectric sensors. Variations in structural behaviour and geometry were measured, and the load and μstrains during operational conditions were quantified in the time domain at a specific frequency. The lead zirconium titanate (PZT) sensors were able to distinguish between material types and thicknesses. Moreover, this work covers frequency selection and optimisation from 20 Hz to 300 kHz. Significant differences in terms of optimal operating frequencies and sensitivity were found in both structures. The influence of the PZT voltage applied was assessed to reduce power consumption without signal loss, and calibration to μstrains and loads was performed.This research was funded by Basque Government, grant number KK-2019/00051-SMARTRESNAK and
by the European Commission, grant number 869884- RECLAIM
Fighting the disagreement in Explainable Machine Learning with consensus
Machine learning (ML) models are often valued by the accuracy of their
predictions. However, in some areas of science, the inner workings of models
are as relevant as their accuracy. To understand how ML models work internally,
the use of interpretability algorithms is the preferred option. Unfortunately,
despite the diversity of algorithms available, they often disagree in
explaining a model, leading to contradictory explanations. To cope with this
issue, consensus functions can be applied once the models have been explained.
Nevertheless, the problem is not completely solved because the final result
will depend on the selected consensus function and other factors. In this
paper, six consensus functions have been evaluated for the explanation of five
ML models. The models were previously trained on four synthetic datasets whose
internal rules were known in advance. The models were then explained with
model-agnostic local and global interpretability algorithms. Finally, consensus
was calculated with six different functions, including one developed by the
authors. The results demonstrated that the proposed function is fairer than the
others and provides more consistent and accurate explanations.Comment: 21 pages, 7 figure
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