A model assisted ionospheric electron density reconstruction method based on vertical TEC data ingestion

A technique to reconstruct the electron density of the ionosphere starting from total electron content values has been developed using the NeQuick ionospheric electron density model driven by its effective ionization parameter Az. The technique is based on the computation of Az values for a suitable worldwide grid of points. A simple way to obtain relevant Az grids is to use global vertical Total Electron Content (TEC) maps to define for each grid point as Az value, the one that minimizes the difference between the experimental and the modeled vertical TEC. Having a global grid of Az values it is possible to compute the electron density at any point in the ionosphere using NeQuick. As a consequence, slant TEC values for specific ground station to satellite links or ionosphere peak parameter values at any location can be calculated. The results of the comparisons between experimental and reconstructed slant TEC as well as experimental and reconstructed peak parameters values indicate that the proposed reconstruction method can be used to reproduce the observed ionosphere in a realistic way

Estudio de la degradación de los aceites de oliva sometidos a fritura. I. Determinación estadística del parámetro que mejor cuantifica esta degradación

On designing this experiment, besides estimating the initial homogeneity of the six oils, which have been studied, all the factors are controlled in a way that only one variable namely, thermoxidation affects the degradation. After the corresponding statistical treatment of the results had been carried out, the conclusion reached was that polar fraction parameter results to been the most specific, besides being the one that best measures the alteration of the heated olive oils.Al diseñar este experimento además de presuponer una homogeneidad inicial en los seis aceites estudiados, se controlaron todos los factores, de forma, que sólo hubiera una variable, la termooxidación, que afectase a la degradación. La conclusión a la que se llegó, después del correspondiente tratamiento estadístico de los resultados, es que el parámetro fracción polar es el más específico y el que mejor mide la alteración de los aceites de oliva calentados

Calibration errors on experimental slant total electron content (TEC) determined with GPS

The Global Positioning System (GPS) has become a powerful tool for ionospheric studies. In addition, ionospheric corrections are necessary for the augmentation systems required for Global Navigation Satellite Systems (GNSS) use. Dual-frequency carrier-phase and code-delay GPS observations are combined to obtain ionospheric observables related to the slant total electron content (sTEC) along the satellite-receiver line-of-sight (LoS). This observable is affected by inter-frequency biases [IFB; often called differential code biases (DCB)] due to the transmitting and the receiving hardware. These biases must be estimated and eliminated from the data in order to calibrate the experimental sTEC obtained from GPS observations. Based on the analysis of single differences of the ionospheric observations obtained from pairs of co-located dual-frequency GPS receivers, this research addresses two major issues: (1) assessing the errors translated from the code-delay to the carrier-phase ionospheric observable by the so-called levelling process, applied to reduce carrier-phase ambiguities from the data; and (2) assessing the short-term stability of receiver IFB. The conclusions achieved are: (1) the levelled carrier-phase ionospheric observable is affected by a systematic error, produced by code-delay multi-path through the levelling procedure; and (2) receiver IFB may experience significant changes during 1 day. The magnitude of both effects depends on the receiver/antenna configuration. Levelling errors found in this research vary from 1.4 total electron content units (TECU) to 5.3 TECU. In addition, intra-day vaiations of code-delay receiver IFB ranging from 1.4 to 8.8 TECU were detected.Facultad de Ciencias Astronómicas y Geofísica

Nematodos: indicadores del estado y procesos del suelo en un sistema frutícola

Se estudió la condición del suelo utilizando el análisis de la comunidad de nematodos en distintas coberturas vegetales en los espacios interfilares de un cultivo de pera. Se investigó los efectos de las coberturas (alfalfa+pastos AP, festuca F y vegetación espontánea VE) durante la primavera 2012 y 2013. Se evaluó nematofauna, materia orgánica del suelo (MOS) y materia seca de las coberturas. El aporte de materia seca, la MOS, y los índices de enriquecimiento y de nematodos fitófagos fueron mayores en AP que en los tratamientos VE y F. El índice de estructura fue bajo y no fue afectado por el tratamiento. La relación fungívoros/bacteriófagos indicó que la descomposición de la MOS fue principalmente mediada por bacterias en todas las coberturas. La mezcla AP puede proveer un incremento en la capacidad de reciclado de nutrientes del suelo para el crecimiento de la pera al aumentar los nematodos bacteriófagos.The nematode community analysis in different cover crops at inter-row spaces of a pear orchard was employed to study soil condition. The effects of three cover crop treatments (alfalfa+grasses (AP), fescue (F), and spontaneous vegetation (VE)) were investigated during spring 2012 and 2013. Nematofauna, soil organic matter (SOM) and cover crop dry matter were assessed. Plant feeding nematodes were dominant and comprised more than 50% of the total population in each treatment. The addition of dry matter, SOM, as well as the enrichment and the plant-parasitic indexes were higher in AP than either in VE or F. The structure index was low and was not affected by treatments. The fungivores to bacterivores ratio indicated that the SOM decomposition was mainly mediated by bacteria in all cover crops. AP mixture can increase the soil nutrient recycling capacity for pear trees growth because the number of bacterivores increases.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Nematodos: indicadores del estado y procesos del suelo en un sistema frutícola

Se estudió la condición del suelo utilizando el análisis de la comunidad de nematodos en distintas coberturas vegetales en los espacios interfilares de un cultivo de pera. Se investigó los efectos de las coberturas (alfalfa+pastos AP, festuca F y vegetación espontánea VE) durante la primavera 2012 y 2013. Se evaluó nematofauna, materia orgánica del suelo (MOS) y materia seca de las coberturas. El aporte de materia seca, la MOS, y los índices de enriquecimiento y de nematodos fitófagos fueron mayores en AP que en los tratamientos VE y F. El índice de estructura fue bajo y no fue afectado por el tratamiento. La relación fungívoros/bacteriófagos indicó que la descomposición de la MOS fue principalmente mediada por bacterias en todas las coberturas. La mezcla AP puede proveer un incremento en la capacidad de reciclado de nutrientes del suelo para el crecimiento de la pera al aumentar los nematodos bacteriófagos.The nematode community analysis in different cover crops at inter-row spaces of a pear orchard was employed to study soil condition. The effects of three cover crop treatments (alfalfa+grasses (AP), fescue (F), and spontaneous vegetation (VE)) were investigated during spring 2012 and 2013. Nematofauna, soil organic matter (SOM) and cover crop dry matter were assessed. Plant feeding nematodes were dominant and comprised more than 50% of the total population in each treatment. The addition of dry matter, SOM, as well as the enrichment and the plant-parasitic indexes were higher in AP than either in VE or F. The structure index was low and was not affected by treatments. The fungivores to bacterivores ratio indicated that the SOM decomposition was mainly mediated by bacteria in all cover crops. AP mixture can increase the soil nutrient recycling capacity for pear trees growth because the number of bacterivores increases.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Nematodos: indicadores del estado y procesos del suelo en un sistema frutícola

Se estudió la condición del suelo utilizando el análisis de la comunidad de nematodos en distintas coberturas vegetales en los espacios interfilares de un cultivo de pera. Se investigó los efectos de las coberturas (alfalfa+pastos AP, festuca F y vegetación espontánea VE) durante la primavera 2012 y 2013. Se evaluó nematofauna, materia orgánica del suelo (MOS) y materia seca de las coberturas. El aporte de materia seca, la MOS, y los índices de enriquecimiento y de nematodos fitófagos fueron mayores en AP que en los tratamientos VE y F. El índice de estructura fue bajo y no fue afectado por el tratamiento. La relación fungívoros/bacteriófagos indicó que la descomposición de la MOS fue principalmente mediada por bacterias en todas las coberturas. La mezcla AP puede proveer un incremento en la capacidad de reciclado de nutrientes del suelo para el crecimiento de la pera al aumentar los nematodos bacteriófagos.The nematode community analysis in different cover crops at inter-row spaces of a pear orchard was employed to study soil condition. The effects of three cover crop treatments (alfalfa+grasses (AP), fescue (F), and spontaneous vegetation (VE)) were investigated during spring 2012 and 2013. Nematofauna, soil organic matter (SOM) and cover crop dry matter were assessed. Plant feeding nematodes were dominant and comprised more than 50% of the total population in each treatment. The addition of dry matter, SOM, as well as the enrichment and the plant-parasitic indexes were higher in AP than either in VE or F. The structure index was low and was not affected by treatments. The fungivores to bacterivores ratio indicated that the SOM decomposition was mainly mediated by bacteria in all cover crops. AP mixture can increase the soil nutrient recycling capacity for pear trees growth because the number of bacterivores increases.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Human Preferences as Dueling Bandits

© 2022 Association for Computing Machinery. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in SIGIR '22: Proceedings of the 45th International ACM SIGIR Conference on Research and Development in Information Retrieval, http://dx.doi.org/10.1145/3477495.3531991The dramatic improvements in core information retrieval tasks engendered by neural rankers create a need for novel evaluation methods. If every ranker returns highly relevant items in the top ranks, it becomes difficult to recognize meaningful differences between them and to build reusable test collections. Several recent papers explore pairwise preference judgments as an alternative to traditional graded relevance assessments. Rather than viewing items one at a time, assessors view items side-by-side and indicate the one that provides the better response to a query, allowing fine-grained distinctions. If we employ preference judgments to identify the probably best items for each query, we can measure rankers by their ability to place these items as high as possible. We frame the problem of finding best items as a dueling bandits problem. While many papers explore dueling bandits for online ranker evaluation via interleaving, they have not been considered as a framework for offline evaluation via human preference judgments. We review the literature for possible solutions. For human preference judgments, any usable algorithm must tolerate ties, since two items may appear nearly equal to assessors, and it must minimize the number of judgments required for any specific pair, since each such comparison requires an independent assessor. Since the theoretical guarantees provided by most algorithms depend on assumptions that are not satisfied by human preference judgments, we simulate selected algorithms on representative test cases to provide insight into their practical utility. Based on these simulations, one algorithm stands out for its potential. Our simulations suggest modifications to further improve its performance. Using the modified algorithm, we collect over 10,000 preference judgments for pools derived from submissions to the TREC 2021 Deep Learning Track, confirming its suitability. We test the idea of best-item evaluation and suggest ideas for further theoretical and practical progress.We thank Mark Smucker, Gautam Kamath, and Ben Carterette for their feedback. This research was supported by the Natural Science and Engineering Research Council of Canada through its Discovery Grants program

Data ingestion into NeQuick 2

NeQuick 2 is the latest version of the NeQuick ionosphere electron density model developed at the Aeronomy and Radiopropagation Laboratory of the Abdus Salam International Centre for Theoretical Physics (ICTP) - Trieste, Italy with the collaboration of the Institute for Geophysics, Astrophysics and Meteorology of the University of Graz, Austria. It is a quick-run model particularly designed for trans-ionospheric propagation applications that has been conceived to reproduce the median behavior of the ionosphere. To provide 3-D specification of the ionosphere electron density for current conditions, different ionosphere electron density retrieval techniques based on the NeQuick adaptation to GPS-derived Total Electron Content (TEC) data and ionosonde measured peak parameters values have been developed. In the present paper the technique based on the ingestion of global vertical TEC map into NeQuick 2 will be validated and an assessment of the capability of the model to reproduce the ionosphere day-to-day variability will also be performed. For this purpose hourly GPS-derived global vertical TEC maps and hourly foF2 values from about 20 ionosondes corresponding to one month in high solar activity and one month in low solar activity period will be used. Furthermore, the first results concerning the ingestion of space-based GPS-derived TEC data will be presented.Facultad de Ciencias Astronómicas y Geofísica

Design and Empirical Validation of a LoRaWAN IoT Smart Irrigation System

[Abstract] In some parts of the world, climate change has led to periods of drought that require managing efficiently the scarce water and energy resources. This paper proposes an IoT smart irrigation system specifically designed for urban areas where remote IoT devices have no direct access to the Internet or to the electrical grid, and where wireless communications are difficult due to the existence of long distances and multiple obstacles. To tackle such issues, this paper proposes a LoRaWAN-based architecture that provides long distance and communications with reduced power consumption. Specifically, the proposed system consists of IoT nodes that collect sensor data and send them to local fog computing nodes or to a remote cloud, which determine an irrigation schedule that considers factors such as the weather forecast or the moist detected by nearby nodes. It is essential to deploy the IoT nodes in locations within the provided coverage range and that guarantee good speed rates and reduced energy consumption. Due to this reason, this paper describes the use of an in-house 3D-ray launching radio-planning tool to determine the best locations for IoT nodes on a real medium-scale scenario (a university campus) that was modeled with precision, including obstacles such as buildings, vegetation, or vehicles. The obtained simulation results were compared with empirical measurements to assess the operating conditions and the radio planning tool accuracy. Thus, it is possible to optimize the wireless network topology and the overall performance of the network in terms of coverage, cost, and energy consumption.This work was funded by Xunta de Galicia (ED431C 2016-045, ED431G/01) and Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE), Project RTI2018-095499-B-C31Xunta de Galicia; ED431C 2016-045Xunta de Galicia; ED431G/0

Broadband characterisation of interior materials and surface scattering using terahertz time-domain spectroscopy

Indoor wireless communications need to move towards Terahertz (THz) frequencies in order to keep up with society's demand for data transmission, but this change is currently hindered by limited knowledge of material properties and propagation and scattering models at these frequencies. The dielectric properties of common household materials are investigated here with a twofold objective: (1) to extend the library of material properties at THz, and (2) to estimate and disentangle losses in scattering measurements in order to facilitate propagation, scattering and, ultimately, channel models