Efficient large-scale image search with a vocabulary tree

The task of searching and recognizing objects in images has become an important research topic in the area of image processing and computer vision. Looking for similar images in large datasets given an input query and responding as fast as possible is a very challenging task. In this work the Bag of Features approach is studied, and an implementation of the visual vocabulary tree method from Nist´er and Stew´enius is presented. Images are described using local invariant descriptor techniques and then indexed in a database using an inverted index for further queries. The descriptors are quantized according to a visual vocabulary, creating sparse vectors, which allows to compute very efficiently, for each query, a ranking of similarity for indexed images. The performance of the method is analyzed varying different factors, such as the parameters for the vocabulary tree construction, different techniques of local descriptors extraction and dimensionality reduction with PCA. It can be observed that the retrieval performance increases with a richer vocabulary and decays very slowly as the size of the dataset grows.Fil: Uriza, Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Gómez Fernández, Francisco Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Rais, Martín. Escuela Normal Superior de Cachan; Franci

Control charts based on MATLAB statistical and visualization tools as a compatible with e-learning methodology in the context of quality control

[EN] The advanced tools for statistical process control in the context of management and quality control are very important for students of technology degrees, even more so in the current industry 4.0 context and considering the new strategies and quality philosophies like Six Sigma. This work shows a learning activity compatible with e-learning methodology based on the use of Matlab® to improve the teaching-learning process for quality control based on the generation of different random datasets in matrix form so that they are processed by each student using different statistical and data visualization tools. Three different real situations are addressed based on the nature of the data: one case of a fully statistically controlled process, one case of a process with a violation in the variability, and finally, one case of a process with violation either in the centering and variability. A pilot study with a small group of students is addressed and subsequently the perception of the activity is evaluated using a questionnaire. The activity was perceived by the students as useful and scalableS

De churras y de merinas: ¿biodiversidad en la ingeniería? Discurso del Académico electo Excmo. Sr. D. Roberto Fernández de Caleya y Álvarez, leído en el acto de recepción pública el día 30 de octubre de 2001 y contestación del académico Excmo. Sr. D. José Antonio Martín Pereda

En esta obra se recoge el discurso que pronunció D. Roberto Fernández de Caleya al ser nombrado miembro de la Academia de Ingeniería y la contestación de Martín Pereda, donde recuerda y analiza la trayectoria vital y académica del nuevo académico

Observaciones territoriales. El proyecto como pensamiento.

Universidad Pablo de OlavideMinisterio de Ciencia e Innovación CSO2009-06819-EUniversidad de Granada 1975-200

Arrays de sensores interferométricos recirculantes de fibra óptica

Two discrete interferometric sensors' arrays have been analysed from time división multiplexing of recirculating crossed loop structures based on singlemode optical fiber. Intensity impulsive responses for both arrays have been obtained and compared under different design considerations, calculating Ihe system coupling constants, signial to interference noise ratio, input pulse repetition rate and duty cycle for each case. First experimental results are shown in this paper and very simple temperature and pressure sensing applicalions are suggested from here

Increasing ventilation in drowning resuscitation − A cross-over randomized simulation study of ventilation during automated external defibrillator analysis pauses

Objective The aim of this study was to analyze the feasibility of a new resuscitation strategy in which breaths are provided during automated external defibrillator (AED) rhythm analysis, and to evaluate its impact on chest compressions (CC) quality and the peri-analysis time. Method A randomized simulation study, comparing two cardiopulmonary resuscitations strategies, has been conducted: the standard strategy (S1) with strategy involving ventilation during AED analysis (S2). Thirty lifeguards have performed both strategies in a cross-over study design during 10 min of CPR. Results The number of ventilations per 10 min increases from 47 (S1) to 72 (S2) (p < 0.001). This results in the delivery of an additional 17.1 L of insufflated air in S2 compared to S1 (p < 0.001). There have been no significant changes in frequency and total number of CC. These findings correspond to a reduction of the non-ventilation period from 176 s (S1) to 48 s (S2). Conclusions This simulation study suggests that it is feasible to increase the number of ventilations during resuscitation following drowning, without affecting the quantity and quality of chest compressions. The results of this study may serve as a foundation for further investigation into optimal ventilation strategies in this contex

Robust Principal Component Analysis Based On Trimming Around Affine Subspaces

Principal Component Analysis (PCA) is a widely used technique for reducing dimensionality of multivariate data. The principal component subspace is defined as the affine subspace of a given dimension d giving the best fit to the data. However, PCA suffers from a well-known lack of robustness. As a robust alternative, one can resort to an impartial trimming based approach. Here one searches for the best subsample containing a proportion 1 − α of the observations, with 0 < α < 1, and the best d-dimensional affine subspace fitting this subsample, yielding the trimmed principal component subspace. A population version will be given and existence of a solution to both the sample and population problem will be proven. Moreover, under mild conditions, the solutions of the sample problem are consistent toward the solutions of the population problem. The robustness of the method is studied by proving quantitative robustness, computing the breakdown point, and deriving the influence functions. Furthermore, asymptotic efficiencies at the normal model are derived, and finite sample efficiencies of the estimators are studied by means of a simulation studyEstadística e I

The Llamas de Cabrera gold district, a new discovery in the Variscan basement of northwest Spain: A fluid inclusion and stable isotope study

[EN] The northwest of the Iberian Massif is well known to host numerous gold mineralizations which were exploited during Roman times. This study presents a multidisciplinary approach leading to the mineralogical, fluid inclusions, and geochemical characterization of the recently rediscovered Roman gold district of Llamas de Cabrera. Gold occurs in extensional quartz veins hosted in the upper layers of the Lower to Middle Ordovician Armorican quartzite and occasionally in the overlaying Middle Ordovician slates from Luarca Formation. The veins are characterized by multistage ore deposition developed along three hydrothermal stages: As–Fe (I), As–Fe (II), and Au–Zn–Cu–Pb, followed by late supergene alteration processes. The fluid inclusion study undertaken on mineralized quartz revealed the presence of three types of fluids: (1) CO2–(CH4) fluid inclusions, (2) aqueous-carbonic fluid inclusions dominated by CO2 and subordinate CH4 related to quartz–arsenopyrite–pyrite deposition, and (3) aqueous fluid inclusions related to the Au-sulfide deposition. In conjunction with arsenopyrite geothermometry and fluid-inclusion data an attempt was made to determine the P–T conditions of ore formation. Changes occurred in the P–T conditions fromarsenopyrite and pyrite deposition in quartz veins from aqueous-carbonic fluids at 300–390 °C and 200–220 MPa towards 180–310 °C and b200 MPa at the stage of gold from aqueous fluids.Mixing of two aqueous fluids of relatively contrasted salinity were favorable factors for decreasing gold solubility and could allow gold deposition. The δ34S values are similar for the two As–Fe stages, +8.0‰ to +16.3‰ and +9.0‰ to +19.5‰ respectively, and for the post-S1 pyrites from siliciclastic Luarca Formation suggesting a comparable sulfur source. Combining calculated δ18O values of fluids of+6.7 to+9.4‰with fluid inclusion data indicates that fluids of unknown origin are largely equilibrated withmetamorphic lithologies at medium–high temperatures. The ascent of some late Variscan magmatic bodies, not exposed at the present day erosion level, provides the heat source for convective water circulation. Gold quartz veins from Llamas de Cabrera display similar features and processes to related deposits of similar type elsewhere in the Variscan belt of western Europe (northwest and central/western Iberia, French Massif Central, BohemianMassif). However Llamas de Cabrera shows certain differences, such as the non-appearance of igneous rocks in the area and the absence of Sb-rich minerals compared to some Variscan Sb–Au deposits, including northern, central, and western Iberia. This last could probably be due to a greater depth of formation for the As–Au veins in comparison to Sb–Au veins.SIThis research has been funded through the research project 2005/ 103, Diputación Provincial de León

Potential climatic influence on maximum stand carrying capacity for 15 Mediterranean coniferous and broadleaf species

Climate change projections for the Mediterranean basin predict a continuous increase in extreme drought and heat episodes, which will affect forest dynamics, structure and composition. Understanding how climate influences the maximum size-density relationship (MSDR) is therefore critical to designing adaptive silvicultural guidelines based on the potential stand carrying capacity of tree species. With this aim, data from the Third Spanish National Forest Inventory (3NFI) and WorldClim databases were used to analyze climate-related variations of the maximum stand carrying capacity for 15 species from the Pinus, Fagus and Quercus genera. First, basic MSDR were fitted using linear quantile regression and observed size-density data from monospecific 3NFI plots. Reference values for maximum stocking, expressed in terms of the Maximum Stand Density Index (SDImax), were estimated by species. Then, climate-dependent MSDR models including 35 annual and seasonal climatic variables were fitted. The best climate-dependent models, based on the Akaike Information Criteria (AIC) index, were used to determine the climatic drivers affecting MSDR, to analyze general and species-specific patterns and to quantify the impact of climate on maximum stand carrying capacity. The results showed that all the selected climate-dependent models improved the goodness of fit over the basic models. Among the climatic variables, spring and summer maximum temperatures were found to be key drivers affecting MSDR for the species studied. A common trend was also found across species, linking warmer and drier conditions to smaller SDImax values. Based on projected climate scenarios, this suggests potential reductions in maximum stocking for these species. In this study, a new index was proposed, the Q index, for evaluating the impact of climate on maximum stand carrying capacity. Our findings highlight the importance of using specific climatic variables to better characterize how they affect MSDR. The models presented in this study will allow us to better explain interactions between climate and MSDR while also providing more precise estimates concerning maximum stocking for different Mediterranean coniferous and broadleaf tree species.Industrial PhD project [grant DI-15-07722]Torres Quevedo programme [grant PTQ-12-05409

Asymmetric synthesis of Rauhut-Currier-type esters via Mukaiyama-Michael reaction to acylphosphonates under bifunctional catalysis

A highly enantioselective organocatalytic Mukaiyama-Michael reaction of silyloxy dienes and α,β-unsaturated acyl phosphonates under bifunctional organocatalysis is presented. The new reactivity triggered by the catalyst conducted to Rauhut-Currier type esters, via a formal conjugate addition to α,β-unsaturated esters. This protocol proceeds under mild conditions with complete regioselectivity and excellent enantiocontrolWe are grateful to the Spanish Government (CTQ2015-64561-R and CTQ2016-76061-P) and the European Research Council (ERCCG-UNBICAT, contract number: 647550). J. A. F.-S. and V. L.-M. thank the Spanish Government for a Juan de la Cierva Contract and the Universidad Auto´noma de Madrid for a predoctoral fellowship (FPI-UAM), respectively. Financial support from the Spanish Ministry of Economy and Competitiveness, through the ‘‘Maria de Maeztu’’ Program of Excellence in R&D (MDM-2014-0377), is also acknowledged. We acknowledge the generous allocation of computing time at the CCC (UAM