Space-Time diversity for NLOS mitigation in TDOA-based positioning systems

This paper studies the potential impact of using space-Time information in the mitigation of the Non-LineOf-Sight condition in mobile subscriber's positioning systems. First of all, this work discusses the positioning problem based on measures of Time Differences Of Arrival departing from a more exact characterization of the signal statistics and including some geometrical restrictions to achieve an improved accurate. Furthermore, a novel approach that integrates signal propagation characteristics to information provided by a suitable timing estimation model based on Cramer Rao Bound for a Rayleigh-fading channel, when antenna arrays are used at the receiver and when a set ofchannel vector estimates are available, has been introduced to study the positive benefits of space-Time diversity. These approaches are evaluated within a realistic simulation scenario.Peer ReviewedPostprint (published version

Gobierno y desempeño institucional en las IES: caso de la Universidad de Santander

Although the concept of governance has gained a leading role in the discourse of academics, researchers and practitioners of public affairs, there are no references that describe its use by Higher Education Institutions (HEIs), nor its evolutionary process, which implies a transformation towards intelligent governance. The objective of this research is to present a review based on the analysis of the different uses and meanings of the concept of governance and corporate governance in HEIs, taking as an object of study the case of the University of Santander UDES, located in Bucaramanga, Santander, Colombia from a qualitative approach with a descriptive-analytical scope. Among the main results, the identification of seven fundamental pillars stands out, where some of them are executed without a guiding structure or guideline, but more because of a need resulting from the pace of globalization and development of the countries; and others are simply not considered.Si bien el concepto de gobernanza ha ganado un espacio protagónico en el discurso de académicos, investigadores y practicantes de los asuntos públicos, no se encuentran referentes que describan su uso por parte de las Instituciones de Educación Superior (IES), ni su proceso evolutivo, el cual implica una transformación hacia la gobernanza inteligente. La presente investigación tiene como objetivo presentar una revisión que parte del análisis de los diferentes usos y acepciones del concepto de gobernanza y gobierno corporativo en las IES, tomando como objeto de estudio el caso de la Universidad de Santander UDES, ubicada en Bucaramanga, Santander, Colombia a partir de un enfoque cualitativo con alcance descriptivo-analítico.  Entre los principales resultados, se destaca la identificación de siete pilares fundamentales, donde algunos de ellos se ejecutan sin estructura o directriz orientadora, sino más como consecuencia de una necesidad producto del ritmo de globalización y desarrollo de los países; y otros sencillamente no son considerados

Mini-Presurímetro de laboratorio (MPMTLAB)

En este artículo se presentan los resultados de la campaña experimental obtenidos de la ejecución de 6 ensayos de suelo fino a diferentes porcentajes (%) de humedad, realizadas en el “MINI-PRESURIMETRO DE LABORATORIO (MPMTLAB)”. Además, se presenta el ensamble, la calibración inicial del equipo y el procedimiento del ensayo. Dentro de la metodología experimental de esta campaña se tuvo en consideración la densidad proctor del material para la realización de los primeros cuatro (4) ensayos y una densidad menor para la ejecución de los dos (2) últimos ensayos, teniendo en cuenta presiones inferiores a los 10Mpa. La finalidad de este ensayo es la determinación de los siguientes parámetros: Módulo de deformación presiométrico (Ep), la presión límite (Pl) y la presión de fluencia (Pf). y finalmente, la calibración inicial de este equipo.This article presents the results of the experimental campaign obtained from the execution of 6 fine soil tests at different percentages (%) of humidity, carried out in the "LABORATORY MINI-PRESSURE METER (MPMTLAB)". In addition, the assembly, the initial calibration of the equipment and the test procedure are presented. Within the experimental methodology of this campaign, the proctor density of the material was taken into consideration for the performance of the first four (4) tests and a lower density for the execution of the last two (2) tests, taking into account pressures lower than the 10Mpa. The purpose of this test is to determine the following parameters: Modulus of pressuremetric deformation (Ep), limit pressure (Pl) and yield pressure (Pf). and finally, the initial calibration of this equipment

Comparative Economic Analysis Between Endogenous and Recombinant Production of Hyaluronic Acid

Hyaluronic acid (HA) is a biopolymer with a wide range of applications, mainly in the cosmetic and pharmaceutical sectors. Typical industrial-scale production utilizes organisms that generate HA during their developmental cycle, such as Streptococcus equi sub. zooepidemicus. However, a significant disadvantage of using Streptococcus equi sub. zooepidemicus is that it is a zoonotic pathogen, which use at industrial scale can create several risks. This creates opportunities for heterologous, or recombinant, production of HA. At an industrial scale, the recovery and purification of HA follow a series of precipitation and filtration steps. Current recombinant approaches are developing promising alternatives, although their industrial implementation has yet to be adequately assessed. The present study aims to create a theoretical framework to forecast the advantages and disadvantages of endogenous and recombinant strains in production with the same downstream strategy. The analyses included a selection of the best cost-related recombinant and endogenous production strategies, followed by a sensitivity analysis of different production variables in order to identify the three most critical parameters. Then, all variables were analyzed by varying them simultaneously and employing multiple linear regression. Results indicate that, regardless of HA source, production titer, recovery yield and bioreactor scale are the parameters that affect production costs the most. Current results indicate that recombinant production needs to improve current titer at least 2-fold in order to compete with costs of endogenous production. This study serves as a platform to inform decision-making for future developments and improvements in the recombinant production of HA

Coffee maturity classification using convolutional neural networks and transfer learning

This work presents a framework for coffee maturity classification from multispectral image data based on Convolutional Neural Networks (CNNs). The system leverages the use of multispectral image acquisition systems that generate large amounts of data, by taking advantage of the ability of CNNs to extract meaningful patterns from very high-dimensional data. We validated the use of five different popular CNN architectures on the classification of cherry coffee fruits according to their ripening stage. The different models were trained on a training dataset balanced in different ways, which resulted in a top accuracy higher than 98% when applied to the classification of 600 coffee fruits in 5 different stages of ripening. This work has the potential of providing the farmer with a high-quality, optimized, accurate and viable method for classifying coffee fruits. In order to foster future research in this area, the data used in this work, which was acquired with a custom-developed multispectral image acquisition system, have been released

The general fault in our fault lines

Pervading global narratives suggest that political polarization is increasing, yet the accuracy of such group meta-perceptions has been drawn into question. A recent US study suggests that these beliefs are inaccurate and drive polarized beliefs about out-groups. However, it also found that informing people of inaccuracies reduces those negative beliefs. In this work, we explore whether these results generalize to other countries. To achieve this, we replicate two of the original experiments with 10,207 participants across 26 countries. We focus on local group divisions, which we refer to as fault lines. We find broad generalizability for both inaccurate meta-perceptions and reduced negative motive attribution through a simple disclosure intervention. We conclude that inaccurate and negative group meta-perceptions are exhibited in myriad contexts and that informing individuals of their misperceptions can yield positive benefits for intergroup relations. Such generalizability highlights a robust phenomenon with implications for political discourse worldwide

Risk factors associated with adverse fetal outcomes in pregnancies affected by Coronavirus disease 2019 (COVID-19): a secondary analysis of the WAPM study on COVID-19.

Objectives To evaluate the strength of association between maternal and pregnancy characteristics and the risk of adverse perinatal outcomes in pregnancies with laboratory confirmed COVID-19. Methods Secondary analysis of a multinational, cohort study on all consecutive pregnant women with laboratory-confirmed COVID-19 from February 1, 2020 to April 30, 2020 from 73 centers from 22 different countries. A confirmed case of COVID-19 was defined as a positive result on real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay of nasal and pharyngeal swab specimens. The primary outcome was a composite adverse fetal outcome, defined as the presence of either abortion (pregnancy loss before 22 weeks of gestations), stillbirth (intrauterine fetal death after 22 weeks of gestation), neonatal death (death of a live-born infant within the first 28 days of life), and perinatal death (either stillbirth or neonatal death). Logistic regression analysis was performed to evaluate parameters independently associated with the primary outcome. Logistic regression was reported as odds ratio (OR) with 95% confidence interval (CI). Results Mean gestational age at diagnosis was 30.6+/-9.5 weeks, with 8.0% of women being diagnosed in the first, 22.2% in the second and 69.8% in the third trimester of pregnancy. There were six miscarriage (2.3%), six intrauterine device (IUD) (2.3) and 5 (2.0%) neonatal deaths, with an overall rate of perinatal death of 4.2% (11/265), thus resulting into 17 cases experiencing and 226 not experiencing composite adverse fetal outcome. Neither stillbirths nor neonatal deaths had congenital anomalies found at antenatal or postnatal evaluation. Furthermore, none of the cases experiencing IUD had signs of impending demise at arterial or venous Doppler. Neonatal deaths were all considered as prematurity-related adverse events. Of the 250 live-born neonates, one (0.4%) was found positive at RT-PCR pharyngeal swabs performed after delivery. The mother was tested positive during the third trimester of pregnancy. The newborn was asymptomatic and had negative RT-PCR test after 14 days of life. At logistic regression analysis, gestational age at diagnosis (OR: 0.85, 95% CI 0.8-0.9 per week increase; pPeer reviewe

Enzyme production from food wastes using a biorefinery concept

According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes