Una metodología para la especificación, evaluación y generación de información de una librería de datos multiespectrales próximos y remotos

RESUMEN Una de las principales motivaciones para desarrollar esta tesis doctoral ha sido el enorme interés que despierta en estos momentos la gestión de los recursos naturales de nuestro planeta. En esa línea, el trabajo de investigación llevado a cabo establece un marco metodológico que permite la especificación, evaluación y generación de información relativa a la respuesta espectral de cubiertas terrestres correspondientes a un ecosistema Mediterráneo. Para ello, el documento presenta un protocolo estructurado, completo y riguroso de recopilación de información procedente de registros espectrales de componentes puros en campo próximo (endmembers) como base fundamental para los nuevos algoritmos propuestos. La información generada durante todo el proceso será posible, además, incorporarla a una librería de datos espectrales registrados tanto en campo próximo como en campo remoto. Por otro lado las dimensiones de los píxeles espaciales que se manejan actualmente procedentes tanto de los sensores multiespectrales como hiperespectrales contienen un gran número de componentes que contribuyen a la medida del espectro final. En consecuencia, el deseo de extraer a partir de dicho espectro los materiales que componen la mezcla así como sus proporciones es vital para numerosas aplicaciones. La complejidad y en ocasiones la no linealidad de la respuesta espectral mixta obtenida por los sensores remotos requiere nuevos algoritmos de modelado que tengan en cuenta la contribución de la respuesta conjunta de los componentes que generan dicha información. Con esta idea en mente, este documento presenta nuevos modelos de mezcla analizando sus propiedades tanto desde un punto de vista estadístico como inferencial. Además la tesis desarrolla diversos métodos para la construcción de estimadores óptimos a partir de las muestras tomadas en campo próximo en función de las características del terreno analizado. Estos estimadores permitirán no sólo establecer intervalos de confianza y test de hipótesis acerca de los parámetros del modelo de regresión empleado sino también evaluar los valores reales de las medidas de los endmembers existentes en la zona de estudio. Se presenta igualmente un nuevo método de generación de algoritmos de mezcla no lineal denominado MLRP (Multiple Layer Radiance Pattern), basado en los conceptos de “frondosidad” y “nivel de presencia” de las diferentes cubiertas en la zona analizada. Este nuevo método combina dos enfoques distintos para la mezcla. Por un lado una visión matemática basada en estimadores de mínimos cuadrados y por otro una aproximación física al problema basada en las interacciones (reflexiones, absorciones y transmisiones del flujo lumínico) que tienen lugar en las diferentes capas que conforman las cubiertas analizadas. Con esta doble aproximación se generan nuevos términos de tipo polinomial que serán los elementos básicos para la construcción de los modelos de mezcla no lineal más eficientes. Finalmente los perfiles espectrales de interés obtenidos a partir de los píxeles de una imagen remotamente registrada se comparan con los espectros modelados que se obtienen como resultado de los modelos propuestos. De este modo, los datos espectrales y los resultados del análisis de correlación podrán ser incluidos en una biblioteca o librería espectral integrada. ABSTRACT One of the principal motivations to develop this doctoral thesis has been the enormous interest that nowadays arouses the management of the natural resources of our planet. In this line, the work of investigation carried out establishes a methodological frame that allows the specification, evaluation and generation of information relative to the spectral response of terrestrial covers corresponding to a Mediterranean ecosystem. For that, the document presents a complete and rigorous ground-truth data collection protocol proceeding from spectral records of pure components (endmembers) as fundamental base for the new proposed algorithms. The information generated during the process will be able to incorporate into an electronic spectral library containing information from spectral data registered both in field and in remote sensing methods. Currently, the spatial pixel sizes for multispectral and hyperspectral sensors are often large and because of it, a great number of disparate substances can contribute to the spectrum measured from a single pixel. Consequently, the desire to extract from a spectrum the constituent materials in the mixture, as well as the proportion in which they appear, is important to numerous tactical scenarios in which subpixel detail is valuable. The complexity and in occasions the non linearity of the spectral mixed response obtained by the remote sensors needs new algorithms of modelling that bear in mind the contribution of the joint response of the components that generate the above mentioned information. With this goal in mind, this document presents new models of linear mixture analyzing its properties so much from a statistical point of view as inferencial. In addition, the thesis also develops several methods for the construction of optimal estimators obtained from the samples that take into account the characteristics of the analyzed area. These estimators will allow not only to establish intervals of confidence and test of hypothesis over of the parameters of the regression model but also to evaluate the real measures of the existing endmembers in the study zone. The thesis presents equally a new method of generation of algorithms of non linear mixture named MLRP (Multiple Layer Radiance Pattern), based on the concepts of “luxuriance” and “presence” of the different covers in the analyzed zone. This new method combines two different approaches. On one hand, a mathematical point of view based on least squared estimators methods and on the other hand a physical approximation based on the interactions (reflections, absorptions and transmissions of illuminating solar radiation) that take place in the different layers that conform the analyzed covers. From this double approach a set of new polinomial type terms appear, that will constitute the basic elements for the construction of more efficient non linear mixing models. Finally the spectral profiles of interest obtained from the pixels of a remotely registered image are compared with the modelled spectra that are obtained as result of the proposed models. Thus, the spectral information and the results of the analysis of correlation will be able to be included in an electronic integrated spectral library

An efficient methodology to simulate mixed spectral signatures of land covers through Field Radiometry data

An efficient methodology to simulate mixed spectral signatures of land covers, from endmember data, using linear statistical modelling based on the least squares estimation approach, is proposed. The optimal set of endmember has been obtained by measurements in situ with a field spectroradiometer GER 1500. Also, it is proposed the use of new sub-pixel methods based on statistics and certain “units of sampling” to apply to the landscapes. The resultant point estimations for these new units will be the “observations” and all of them will carry out an special role to simulate the final spectral signature. This methodology is used to simulate spectral signatures of a Mediterranean forest landscape near to Madrid (Spain). Furthermore the spectral signature model obtained through Field Radiometry data will be correlated with the image data of the same zone provided by the Landsat 7 Enhaced Thematic Mapper Plus (ETM+) sensor once corrected. The results obtained in correlation studies seem to conclude its efficiency. At the same time, the results open new research guidelines

Landcover degradation analysis of Mediterranean forest by means of hyperplanes obtained from mixture linear algorithms (MLA)

The percentage alteration of the Mediterranean forest landscape is one of the primary indicators for its degradation. In this sense, the land cover abundances change analysis by using mixture linear algorithms (MLA), is presented like a good alternative to study this degradation. This research analyzes the use of two information sources like Remote Sensing (Landsat-ETM+) and Field Radiometry (GER 1500) to obtain mixture hyperplanes. These are calculated by models based on least square estimations, assuming that each pure land cover (endmember) belonging to any geographic area, behaves as a random variable which distribution function is known. The mixture hyperplanes provide spectral signatures with a suitable correlation level with regard to the supplied from remote satellite sensors once corrected, for the same geographical zone. These established hyperplanes can be used in future researches about Mediterranean forest landscape changes, because they can represent the different levels of its degradation. In this sense, it is proposed that they will feed a land cover spectral library with free accessibility

Radial Line Slot Antenna Design with Groove Gap Waveguide Feed for Monopulse Radar Systems

Radial line slot arrays (RLSAs) are well suited to be used in monopulse radar systems. The excitation of the sum and difference patterns can be achieved by the design of simple feeds as shown in this paper. In this work, a feed system based on the use of a cavity made in groove gap waveguide technology (GGW) is presented. The design is made at 24 GHz but can be easily scaled to higher frequencies as the technology is contact-less and fully made in metal. A good isolation between the sum and difference ports together with a good matching of the two of them is obtained. The radiation patterns of the manufactured antenna are also in good agreement with the simulated ones.This work was supported in part by the Spanish Government, Ministry of Economy, National Program of Research, Development and Innovation under the projects TEC2016-79700-C2-2-R and TEC2017-85529-C3-1-R and by the Madrid Regional Government under the project SPADERADAR “Space Debris Radar” (S2013/ICE-3000) and the FPI grant with reference BES-2015-07523

Measurement of indirect CP asymmetries in D0 → K−K+ and D0 → π−π+ decays using semileptonic B decays

Time-dependent CP asymmetries in the decay rates of the singly Cabibbo-suppressed decays D0 → K−K+ and D0 → π−π+ are measured in pp collision data corresponding to an integrated luminosity of 3.0 fb−1 collected by the LHCb experiment. The D0 mesons are produced in semileptonic b-hadron decays, where the charge of the accompanying muon is used to determine the initial state as D0 or D¯0. The asymmetries in effective lifetimes between D0 and D¯0 decays, which are sensitive to indirect CP violation, are determined to be AΓ(K−K+)=(−0.134±0.077−0.026−0.034)%,AΓ(π−π+)=(−0.092±0.145−0.025−0.033)%, where the first uncertainties are statistical and the second systematic. This result is in agreement with previous measurements and with the hypothesis of no indirect CP violation in D0 decays.S

Precise measurements of the properties of the B1(5721)0,+ and B *2(5747)0,+ states and observation of B+,0π−,+ mass structures

Invariant mass distributions of B+π− and B0π+ combinations are investigated in order to study excited B mesons. The analysis is based on a data sample corresponding to 3.0 fb−1 of pp collision data, recorded by the LHCb detector at centre-of-mass energies of 7 and 8 TeV. Precise measurements of the masses and widths of the B1(5721)0,+ and B2(5747)0,+ states are reported. Clear enhancements, particularly prominent at high pion transverse momentum, are seen over background in the mass range 5850-6000 MeV in both B+π− and B0π+ combinations. The structures are consistent with the presence of four excited B mesons, labelled B J (5840)0,+ and B J (5960)0,+, whose masses and widths are obtained under different hypotheses for their quantum numbersS

Measurement of CP asymmetries and polarisation fractions in B0s→K∗0K¯∗0 decays

An angular analysis of the decay B0s→K∗0K¯∗0 is performed using pp collisions corresponding to an integrated luminosity of 1.0 fb−1 collected by the LHCb experiment at a centre-of-mass energy s√=7 TeV. A combined angular and mass analysis separates six helicity amplitudes and allows the measurement of the longitudinal polarisation fraction f L = 0.201 ± 0.057 (stat.) ± 0.040 (syst.) for the B0s→K∗(892)0K¯∗(892)0 decay. A large scalar contribution from the K ∗0(1430) and K ∗0(800) resonances is found, allowing the determination of additional CP asymmetries. Triple product and direct CP asymmetries are determined to be compatible with the Standard Model expectations. The branching fraction B(Bs→K∗(892)0K¯∗(892)0) is measured to be (10.8 ± 2.1 (stat.) ± 1.4 (syst.) ± 0.6 (f d /f s )) × 10−6.S

Valor pronóstico del índice de riesgo nutricional en receptores de trasplante cardiaco

[Abstract] Introduction and objectives. To study the prognostic impact of preoperative nutritional status, as assessed through the nutritional risk index (NRI), on postoperative outcomes after heart transplantation (HT). Methods. We conducted a retrospective, single-center study of 574 patients who underwent HT from 1991 to 2014. Preoperative NRI was calculated as 1.519 × serum albumin (g/L) + 41.7 × (body weight [kg] / ideal body weight [kg]). The association between preoperative NRI and postoperative outcomes was analyzed by means of multivariable logistic regression and multivariable Cox regression. Results. Mean NRI before HT was 100.9 ± 9.9. According to this parameter, the prevalence of severe nutritional risk (NRI < 83.5), moderate nutritional risk (83.5 ≤ NRI < 97.5), and mild nutritional risk (97.5 ≤ NRI < 100) was 5%, 22%, and 10%, respectively. One year post-transplant mortality rates in these 4 categories were 18.2%, 25.3%, 7.9% and 10.2% (P < .001), respectively. The NRI was independently associated with a lower risk of postoperative infection (adjusted OR, 0.97; 95%CI, 0.95-1.00; P = .027) and prolonged postoperative ventilator support (adjusted OR, 0.96; 95%CI, 0.94-0.98; P = .001). Patients at moderate or severe nutritional risk had significantly higher 1-year post-HT mortality (adjusted HR, 1.55; 95%CI, 1.22-1.97; P < .001). Conclusions. Malnourished patients have a higher risk of postoperative complications and mortality after HT. Preoperative NRI determination may help to identify HT candidates who might benefit from nutritional intervention.[Resumen] Introducción y objetivos. Analizar el impacto del estado nutricional preoperatorio, evaluado mediante el índice de riesgo nutricional (IRN), en el pronóstico tras el trasplante cardiaco (TxC). Métodos. Se realizó un estudio retrospectivo de 574 pacientes que recibieron un TxC entre 1991 y 2014 en un centro. El IRN preoperatorio se calculó como 1,519 × albúmina (g/l) + 41,7 × (peso real [kg] / peso ideal [kg]). La asociación entre IRN preoperatorio y eventos clínicos posoperatorios se analizó mediante modelos multivariables de regresión logística y regresión de Cox. Resultados. El IRN preoperatorio medio de la población del estudio era de 100,9 ± 9,9. Según este parámetro, las prevalencias de riesgo nutricional grave (IRN < 83,5), moderado (83,5 ≤ IRN < 97,5) y leve (97,5 ≤ IRN < 100) antes del TxC eran el 5, el 22 y el 10% respectivamente. Las tasas de mortalidad a 1 año tras el TxC en estas 4 categorías fueron del 18,2, el 25,3, el 7,9 y el 10,2% (p < 0,001) respectivamente. El IRN preoperatorio resultó predictor independiente de menor riesgo de infección posoperatoria (odds ratio ajustada [ORa] = 0,97; intervalo de confianza del 95% [IC95%], 0,95-1,00; p = 0,027) y ventilación mecánica prolongada posoperatoria (ORa = 0,96; IC95%, 0,94-0,98; p = 0,001). Los pacientes con riesgo nutricional moderado a grave mostraron mayor mortalidad a 1 año tras el TxC (hazard ratio ajustada = 1,55; IC95%, 1,22-1,97; p < 0,001). Conclusiones. Los pacientes desnutridos tienen mayor riesgo de complicaciones posoperatorias y muerte tras el TxC. La determinación del IRN podría facilitar la identificación de candidatos a TxC que se beneficien de intervenciones nutricionales en espera del órgano

Observation of the B0→ρ0ρ0 decay from an amplitude analysis of B0→(π+π−)(π+π−)decays

Proton–proton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0fb−1, are analysed to search for the charmless B0→ρ0ρ0decay. More than 600 B0→(π+π−)(π+π−)signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0→ρ0ρ0decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0→ρ0ρ0decays yielding a longitudinally polarised final state is measured to be fL=0.745+0.048−0.058(stat) ±0.034(syst). The B0→ρ0ρ0branching fraction, using the B0→φK∗(892)0decay as reference, is also reported as B(B0→ρ0ρ0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))×10−6S

Search for CP violation in D0→π−π+π0 decays with the energy test

A search for time-integrated CPviolation in the Cabibbo-suppressed decay D0→π−π+π0is performed using for the first time an unbinned model-independent technique known as the energy test. Using proton–proton collision data, corresponding to an integrated luminosity of 2.0fb−1collected by the LHCbdetector at a centre-of-mass energy of √s=8TeV, the world’s best sensitivity to CPviolation in this decay is obtained. The data are found to be consistent with the hypothesis of CPsymmetry with a p-value of (2.6 ±0.5)%S