1,372 research outputs found
Sparse Multi-modal probabilistic Latent Semantic Analysis for Single-Image Super-Resolution
This paper presents a novel single-image super-resolution (SR) approach
based on latent topics in order to take advantage of the semantics pervading
the topic space when super-resolving images. Image semantics has shown to
be useful to relieve the ill-posed nature of the SR problem, however the most
accepted clustering-based approach used to define semantic concepts limits the
capability of representing complex visual relationships. The proposed approach
provides a new probabilistic perspective where the SR process is performed
according to the semantics encapsulated by a new topic model, the Sparse Multimodal
probabilistic Latent Semantic Analysis (sMpLSA). Firstly, the sMpLSA
model is formulated. Subsequently, a new SR framework based on sMpLSA is
defined. Finally, an experimental comparison is conducted using seven learningbased
SR methods over three different image datasets. Experiments reveal the
potential of latent topics in SR by reporting that the proposed approach is able
to provide a competitive performance
Latent Topics-based Relevance Feedback for Video Retrieval
This paper presents a novel Content-Based Video Retrieval approach in order to cope with the semantic gap challenge by means of latent topics. Firstly, a supervised topic model is proposed to transform the classical retrieval approach into a class discovery problem. Subsequently, a new probabilistic ranking function is deduced from that model to tackle the semantic gap between low-level features and high-level concepts. Finally, a short-term relevance feedback scheme is defined where queries can be initialised with samples from inside or outside the database. Several retrieval simulations have been carried out using three databases and seven different ranking functions to test the performance of the presented approach. Experiments revealed that the proposed ranking function is able to provide a competitive advantage within the content-based retrieval field
Incremental probabilistic Latent Semantic Analysis for video retrieval
Recent research trends in Content-based Video Retrieval have shown topic models as an effective tool to deal
with the semantic gap challenge. In this scenario, this paper has a dual target: (1) it is aimed at studying how
the use of different topic models (pLSA, LDA and FSTM) affects video retrieval performance; (2) a novel incremental
topic model (IpLSA) is presented in order to cope with incremental scenarios in an effective and efficient
way. A comprehensive comparison among these four topic models using two different retrieval systems and two
reference benchmarking video databases is provided. Experiments revealed that pLSA is the best model in sparse
conditions, LDA tend to outperform the rest of the models in a dense space and IpLSA is able to work properly in
both cases
Extensional orogenic collapse captured by strike-slip tectonics:
The late Paleozoic collision between Gondwana and Laurussia resulted in the polyphase deformation and
magmatism that characterizes the Iberian Massif of the Variscan orogen. In the Central Iberian Zone, initial con-
tinental thickening (D1; folding and thrusting) was followed by extensional orogenic collapse (D2) responsible
for the exhumation of high-grade rocks coeval to the emplacement of granitoids.
This study presents a tectonometamorphic analysis of the Trancoso-Pinhel region (Central Iberian Zone) to ex-
plain the processes in place during the transition froman extension-dominated state (D2) to a compression-dom-
inated one (D3).Wereveal the existence of low-dipping D2 extensional structures later affected by several pulses
of subhorizontal shortening, each of them typified by upright folds and strike-slip shearing (D3, D4 and D5, as
identified by superimposition of structures). The D2 Pinhel extensional shear zone separates a low-grade domain
from an underlying high-grade domain, and it contributed to the thermal reequilibration of the orogen by facil-
itating heat advection from lower parts of the crust, crustal thinning, decompression melting, and magma intru-
sion. Progressive lessening of the gravitational disequilibrium carried out by this D2 shear zone led to a switch
from subhorizontal extension to compression and the eventual cessation and capture of the Pinhel shear zone
by strike-slip tectonics during renewed crustal shortening. High-grade domains of the Pinhel shear zone were
folded together with low-grade domains to define the current upright folded structure of the Trancoso-Pinhel re-
gion, the D3 Tamames-Marofa-Sátão synform. Newdating of syn-orogenic granitoids (SHRIMP U\\Pb zircon dat-
ing) intruding the Pinhel shear zone, together with the already published ages of early extensional fabrics
constrain the functioning of this shear zone to ca. 331–311 Ma, with maximum tectonomagmatic activity at ca.
321–317 Ma. The capture and apparent cessation of movement of the Pinhel shear zone occurred at ca. 317–
311 Ma
Diseño de filtros planares para radiometrÃa
Diseño de tres prototipos de filtros para apliaciones de radiometrÃa (LICEF) -Filtro microstrip de orden 6, con dos ceros de transmisión. SÃntesis de filtros sin pérdidas. -Filtro microstrip asÃncrono de orden 6, con un cero de transmisión. SÃntesis de filtros sin pérdidas -Filtro microstrip de orden 6 , con dos ceros de transmisión. SÃntesis por técnicas avanzadas de filtros con pérdidas. Procedimiento: -Anális de resonadores sobre diferentes dieléctricos -SÃntesis a partir de matriz de acoplamientos -Simulación con ADS -Simulación con Momentum -Comparación de prototipo
Strike-slip shear zones of the Iberian Massif: Are they coeval?
Strike-slip shear zones of the Variscan orogen are used to derive the evolution of paleostrain and discuss the kinematics of the waning stages
of the Gondwana-Laurussia collision during the amalgamation of Pangea. In the Iberian Massif, the recognition of three late Carboniferous
deformation events related to strike-slip tectonics (D3, D4, D5) in the Trancoso-Pinhel region (Portugal) reveals that late orogenic transcurrent
deformation was episodic and occurred in a short period of time (<15 m.y.). Early stages of strike-slip deformation included dextral and sinistral
shear zones and orogen-parallel upright folds (D3; ca. 311 Ma). These structures followed the development of extensional shear zones (D2) during
the tectonothermal reequilibration of the orogen. D3 structures were deflected and folded by the sinistral D4 Juzbado-Penalva do Castelo
shear zone, dated as ca. 309–305 Ma by SHRIMP (sensitive high-resolution ion microprobe) U-Pb zircon dating of synkinematic granitoids.
D3 and D4 structures were folded under east-west compression (D5) influenced by the strike-slip movement of the dextral Porto-Tomar shear
zone. Variscan movement along the Porto-Tomar shear zone started ca. 304 Ma (onset of the Buçaco basin and syn-D5 granites), but ceased
before ca. 295 Ma (age of the final closure of the Ibero-Armorican arc and crosscutting granites). The contrasting geometry, kinematics, and
timing of these strike-slip shear zones are explained by deformation partitioning upon a rheologically inhomogeneous crust with structural
and tectonothermal anisotropies generated during previous deformation. The convergence vector between Gondwana and Laurussia during
D3–D5 remained the same, and was equivalent to the vector that explains the previous tectonic record (D2) in central and northwestern Iberia
Does a CDO enhance Company Inventiveness? An Empirical Study on new Managerial Positions and Innovation
Digital technology has advanced rapidly in the last few years. Consequently, companies need to transform their business and operations models to keep up with these advances, placing digital transformation (DT) as a top priority. Beyond the possible effects of using more digital technologies, is more innovation. One way in which companies can stimulate DT is by creating a new top-management position, the Chief Digital Officer (CDO). Although evidence has been found about the relationship between digital technologies and innovation, the role of the CDO as an enabler has been less studied. We use difference-in-difference estimators to measure this effect, using a unique dataset with 39 companies that appointed a CDO and 39 comparable companies that did not as a control group. We find a significant increase in patent filings as early as the first year CDO’s appointment. We find evidence that a managerial role can have an effect on innovation
W-NetPan: Double-U network for inter-sensor self-supervised pan-sharpening
The increasing availability of remote sensing data allows dealing with spatial-spectral limitations by means of pan-sharpening methods. However, fusing inter-sensor data poses important challenges, in terms of resolution differences, sensor-dependent deformations and ground-truth data availability, that demand more accurate pan-sharpening solutions. In response, this paper proposes a novel deep learning-based pan-sharpening model which is termed as the double-U network for self-supervised pan-sharpening (W-NetPan). In more details, the proposed architecture adopts an innovative W-shape that integrates two U-Net segments which sequentially work for spatially matching and fusing inter-sensor multi-modal data. In this way, a synergic effect is produced where the first segment resolves inter-sensor deviations while stimulating the second one to achieve a more accurate data fusion. Additionally, a joint loss formulation is proposed for effectively training the proposed model without external data supervision. The experimental comparison, conducted over four coupled Sentinel-2 and Sentinel-3 datasets, reveals the advantages of W-NetPan with respect to several of the most important state-of-the-art pan-sharpening methods available in the literature. The codes related to this paper will be available at https://github.com/rufernan/WNetPan
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