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Jorge Garcia

Publications and source records attributed to Jorge Garcia.

9 recordsLinked to original sources
arXiv2025

Multimodal Sensing for Robot-Assisted Sub-Tissue Feature Detection in Physiotherapy Palpation

Robotic palpation relies on force sensing, but force signals in soft-tissue environments are variable and cannot reliably reveal subtle subsurface features. We present a compact multimodal sensor that integrates high-resolution vision-based tactile imaging with a 6-axis force-torque sensor. In experiments on silicone phantoms with diverse subsurface tendon geometries, force signals alone frequently produce ambiguous responses, while tactile images reveal clear structural differences in presence, diameter, depth, crossings, and multiplicity. Yet accurate force tracking remains essential for maintaining safe, consistent contact during physiotherapeutic interaction. Preliminary results show that combining tactile and force modalities enables robust subsurface feature detection and controlled robotic palpation.

cs.RO↗
arXiv2025

Morphological Image Similarity Search on the ALMA Science Archive Query Interface Using Deep Unsupervised Contrastive Representation Learning

With the exponential growth of astronomical data over time, finding the needles in the haystack is becoming increasingly difficult. The next frontier for science archives is to enable searches not only on observational metadata, but also on the content of the observations themselves. As a step in this direction, we have implemented morphological image similarity search into the ALMA Science Archive (ASA). To achieve this we use self-supervised contrastive affine-transformation-independent representation learning of source morphologies with a deep neural network. For a given image on the ASA web interface, astronomers are presented with a summary view of the morphologically most similar images. Each time an astronomer selects an additional image from that view, the display is instantly updated to show the images most similar to the combination of the selected images. Each selection thus refines the similarity display according to the scientific needs of the astronomer. This is the first time image similarity search has been offered in an astronomical science archive.

astro-ph.IM↗
arXiv2025

Sarrus' Quilt: A Novel Way to Compute Determinants

After analyzing the 4x4 determinant of a matrix, a shortcut was obtained to find such a determinant. Similarly to the Sarrus method for 2x2 or 3x3 determinants, the method consists of laying 19 columns of size 4 each and adding and subtracting some diagonal multiplications. There is a symmetry in the arrangement of these columns. A very symmetric pattern emerged for the 5x5 determinant which was also found. A cyclic pattern was observed for the diagonals of larger determinants when applying this method.

math.GM↗
arXiv2024

Strategies to Counter Artificial Intelligence in Law Enforcement: Cross-Country Comparison of Citizens in Greece, Italy and Spain

This paper investigates citizens' counter-strategies to the use of Artificial Intelligence (AI) by law enforcement agencies (LEAs). Based on information from three countries (Greece, Italy and Spain) we demonstrate disparities in the likelihood of ten specific counter-strategies. We further identified factors that increase the propensity for counter-strategies. Our study provides an important new perspective to societal impacts of security-focused AI applications by illustrating the conscious, strategic choices by citizens when confronted with AI capabilities for LEAs.

cs.AI↗
arXiv2023

Class Number of the Imaginary Quadratic Field and Quadratic Residues Identities

A formula for the sum of quadratic residues modulus a prime $p=4n-1$ is studied. We relate some terms on this formula with roots of quadratics and provide an exhaustive analysis of new concepts based on these roots. A number of formulas for the sum of the quadratic residues are obtained. We finalize the paper by obtaining several identities involving $h(-p)$ the class number of the imaginary quadratic field $\mathbb Q(\sqrt{-p}).$

math.NT↗
arXiv2022

Minimal Constructible Sets

Given an initial family of sets, we may take unions, intersections and complements of the sets contained in this family in order to form a new collection of sets; our construction process is done recursively until we obtain the last family. Problems encountered in this research include the minimum number of steps required to arrive to the last family as well as a characterization of that last family; we solve all those problems. We also define a class of simple families ($n$-minimal constructible) and we analyze the relationships between partitions and separability (our new concept) that lead to interesting results such as finding families based on partitions that generate finite algebras. We prove a number of new results about $n$-minimal constructible families; one major result is that every finite algebra of sets has a generating family which is $n$-minimal constructible for all natural $n$ and we compute the minimum number of steps required to generate an algebra. Another interesting result is a connection between this construction process and Baire's Theorem. This work has a number of possible applications, particularly in the fields of economics and computer science.

math.CO↗
arXiv2002

Active star formation in N11B Nebula in the Large Magellanic Cloud: a sequential star formation scenario confirmed

The second largest HII region in the Large Magellanic Cloud, N11B has been surveyed in the near IR.We present JHKs images of the N11B nebula.These images are combined with CO(1-0) emission line data and with archival NTT and HST/WFPC2 optical images to address the star formation activity of the region.IR photometry of all the IR sources detected is given.We confirm that a second generation of stars is currently forming in the N11B region. Our IR images show the presence of several bright IR sources which appear located towards the molecular cloud as seen from the CO emission in the area.Several of these sources show IR colours with YSO characteristics and they are prime candidates to be intermediate-mass Herbig Ae/Be stars.For the first time an extragalactic methanol maser is directly associated with IR sources embedded in a molecular core.Two IR sources are found at 2"(0.5 pc) of the methanol maser reported position.Additionally, we present the association of the N11A compact HII region to the molecular gas where we find that the young massive O stars have eroded a cavity in the parental molecular cloud, typical of a champagne flow. The N11 region turns out to be a very good laboratory for studying the interaction of winds, UV radiation and molecular gas.Several photodissociation regions are found.

astro-ph↗
arXiv2002

Accurate Monte Carlo critical exponents for Ising lattices

A careful Monte Carlo investigation of the phase transition very close to the critical point (T -> Tc, H -> 0) in relatively large d = 3, s = 1/2 Ising lattices did produce critical exponents beta = 0.3126(4) =~ 5/16, delta^{-1} = 0.1997(4) =~ 1/5 and gamma_{3D} = 1.253(4) =~ 5/4. Our results indicate that, within experimental error, they are given by simple fractions corresponding to the linear interpolations between the respective two-dimensional (Onsager) and four-dimensional (mean field) critical exponents. An analysis of our inverse susceptibility data chi^{-1}(T) vs. /T - Tc/ shows that these data lead to a value of gamma_{3D} compatible with gamma' = gamma and Tc = 4.51152(12), while gamma values obtained recently by high and low temperature series expansions and renormalization group methods are not.

cond-mat.stat-mech↗