Stochastic Earned Value Analysis using Monte Carlo Simulation and Statistical Learning Techniques

The aim of this paper is to describe a new an integrated methodology for project control under uncertainty. This proposal is based on Earned Value Methodology and risk analysis and presents several refinements to previous methodologies. More specifically, the approach uses extensive Monte Carlo simulation to obtain information about the expected behavior of the project. This dataset is exploited in several ways using different statistical learning methodologies in a structured fashion. Initially, simulations are used to detect if project deviations are a consequence of the expected variability using Anomaly Detection algorithms. If the project follows this expected variability, probabilities of success in cost and time and expected cost and total duration of the project can be estimated using classification and regression approaches.Comment: 20 page

Book review: Ralph R. Frerichs: Deadly river - Cholera and cover-up in post-earthquake

As most of PV systems, CPV systems are also affected by mismatching losses, particularly due to misalignment of optics and receivers. As a result, module level power electronics can help to increase their energy yield by making every CPV module deliver it maximum power at the output. Among the different alternatives, solutions based on DC power optimizers exhibit higher conversion efficiencies and lower costs than microinverters. However, while microinverters ensure optimal operation independently from the operating conditions, system design with DC power optimizers must be carefully examined to avoid potential underperformance. This paper describes not only the customized design and validation of a high-efficiency and economical DC power optimizer for HCPV systems, but also a comprehensive analysis of the whole system design to optimize its production under expected working conditions.Main design specifications (electrical parameters of module and number of modules per tracker), as well as supporting information for mismatching losses estimation, have been provided by ASSE within CPVMatch project. This work has received funding from the European Union’s Horizon 2020 research and innovation programme within the project CPVMatch under grant agreement No 640873

Large scale and information effects on cooperation in public good games

The problem of public good provision is central in economics and touches upon many challenging societal issues, ranging from climate change mitigation to vaccination schemes. However, results which are supposed to be applied to a societal scale have only been obtained with small groups of people, with a maximum group size of 100 being reported in the literature. This work takes this research to a new level by carrying out and analysing experiments on public good games with up to 1000 simultaneous players. The experiments are carried out via an online protocol involving daily decisions for extended periods. Our results show that within those limits, participants' behaviour and collective outcomes in very large groups are qualitatively like those in smaller ones. On the other hand, large groups imply the difficulty of conveying information on others' choices to the participants. We thus consider different information conditions and show that they have a drastic effect on subjects' contributions. We also classify the individual decisions and find that they can be described by a moderate number of types. Our findings allow to extend the conclusions of smaller experiments to larger settings and are therefore a relevant step forward towards the understanding of human behaviour and the organisation of our society.A.A. gratefully acknowledges the financial support of the Ministerio de Economía y Competitividad of Spain under grant no. FJCI-2016-28276. This work was also supported by the EU through FET-Proactive Project DOLFINS (contract no. 640772, A.S.) and FET-Open Project IBSEN (contract no. 662725, A.S.), and by the Ministerio de Economía y Competitividad of Spain (grant no. FIS2015-64349-P, J.C. and A.S.) (MINECO/FEDER, UE), and by Ministerio de Ciencia, Innovación y Universidades/FEDER (Spain/UE) through grant PGC2018-098186-B-I00 (BASIC)

PRIMER REGISTRO DE UNA ABERRACIÓN MARRÓN PARA EL CORMORÁN NEOTROPICAL NANNOPTERUM BRASILIANUM DE MÉXICO

En esta nota, reportamos un caso de aberración del plumaje en el cormorán neotropical Nannopterum brasilianum. Se registró la presencia de un color atípico en el plumaje de un individuo observado en un humedal del norte de México. El ave presentaba una aberración marrón, en la que el color negro original fue sustituido por tonos marrón claro y beige pálido. Observamos el ave alimentándose junto a otros cormoranes con una coloración normal y no mostró comportamientos diferentes. La documentación de fenotipos aberrantes es importante para determinar su frecuencia y patrones geográficos de aparición, especialmente en aves acuáticas con distribuciones geográficas extensas como N. brasilianum. Esta observación representa el primer reporte de aberración de plumaje marrón en esta especie

Known by the company we keep: `Triadic influence' as a proxy for compatibility in social relationships

Networks of social interactions are the substrate upon which civilizations are built. Often, we create new bonds with people that we like or feel that our relationships are damaged through the intervention of third parties. Despite their importance and the huge impact that these processes have in our lives, quantitative scientific understanding of them is still in its infancy, mainly due to the difficulty of collecting large datasets of social networks including individual attributes. In this work, we present a thorough study of real social networks of 13 schools, with more than 3,000 students and 60,000 declared positive and negative relations, including tests for personal traits of all the students. We introduce a metric -- the `triadic influence' -- that measures the influence of nearest-neighbors in the relationships of their contacts. We use neural networks to predict the relationships and to extract the probability that two students are friends or enemies depending on their personal attributes or the triadic influence. We alternatively use a high-dimensional embedding of the network structure to also predict the relationships. Remarkably, the triadic influence (a simple one-dimensional metric) achieves the highest accuracy at predicting the relationship between two students. We postulate that the probabilities extracted from the neural networks -- functions of the triadic influence and the personalities of the students -- control the evolution of real social networks, opening a new avenue for the quantitative study of these systems

Reflexiones y aportaciones metodológicas

los aportes reunidos en esta obra, provienen de experiencias previas de trabajo profesional y de investigación, lo cual es resultado de distintos enfoques y vivencias de los grupos de investigación aquí involucrados, los que han interactuado en distintos eventos académicos y específicamente, en seminarios que propiciaron la producción que se reúne en esta publicación colectiva. Finalmente, esta experiencia acumulada es una de las mejores recomendaciones para la lectura por demás interesante y propositivo.El presente libro, identifica los aportes metodológicos del trabajo cotidiano en diferentes capítulos para integrarlos a los propios de las disciplinas del diseño. Asimismo, uno de los capítulos aborda la necesidad de estudiar un contexto de referencia que el destinatario pueda interpretar, entre un canal físico y una conexión psicológica a modo de estrategia interpretativa individual y colectiva. Este discurso, sostienen los coautores, se enmarca en la hermenéutica y dentro de lo colectivo, ya que este proceso se estudia desde las aportaciones del interaccionismo simbólico. Se abandona la construcción de las utopías, a la vez que busca soluciones diseñísticas, actuales y novedosas. Es así que el sentido del mensaje del objeto de diseño como texto conlleva un discurso que no “es realizado por el emisor, sino por el receptor y es la enunciación, narración y reconfiguración de los textos, en donde el discurso conforma una determinada idea de la realidad”

The importance of atmospheric correction for airborne hyperspectral remote sensing of shallow waters: application to depth estimation

Accurate determination of water depth is indispensable in multiple aspects of civil engineering (dock construction, dikes, submarines outfalls, trench control, etc.). To determine the type of atmospheric correction most appropriate for the depth estimation, different accuracies are required. Accuracy in bathymetric information is highly dependent on the atmospheric correction made to the imagery. The reduction of effects such as glint and cross-track illumination in homogeneous shallow-water areas improves the results of the depth estimations. The aim of this work is to assess the best atmospheric correction method for the estimation of depth in shallow waters, considering that reflectance values cannot be greater than 1.5% because otherwise the background would not be seen. This paper addresses the use of hyperspectral imagery to quantitative bathymetric mapping and explores one of the most common problems when attempting to extract depth information in conditions of variable water types and bottom reflectances. The current work assesses the accuracy of some classical bathymetric algorithms (Polcyn? Lyzenga, Philpot, Benny?Dawson, Hamilton, principal component analysis) when four different atmospheric correction methods are applied and water depth is derived. No atmospheric correction is valid for all type of coastal waters, but in heterogeneous shallow water the model of atmospheric correction 6S offers good results

Detection methods predict differences in biology and survival in breast cancer patients

BackgroundThe aim of this study was to measure the biological characteristics involved in tumorigenesis and the progression of breast cancer in symptomatic and screen-detected carcinomas to identify possible differences.MethodsFor this purpose, we evaluated clinical-pathological parameters and proliferative and apoptotic activities in a series of 130 symptomatic and 161 screen-detected tumors.ResultsAfter adjustment for the smaller size of the screen-detected carcinomas compared with symptomatic cancers, those detected in the screening program presented longer disease-free survival (RR = 0.43, CI = 0.19-0.96) and had high estrogen and progesterone receptor concentrations more often than did symptomatic cancers (OR = 3.38, CI = 1.72-6.63 and OR = 3.44, CI = 1.94-6.10, respectively). Furthermore, the expression of bcl-2, a marker of good prognosis in breast cancer, was higher and HER2/neu expression was lower in screen-detected cancers than in symptomatic cancers (OR = 1.77, CI = 1.01-3.23 and OR = 0.64, CI = 0.40-0.98, respectively). However, when comparing prevalent vs incident screen-detected carcinomas, prevalent tumors were larger (OR = 2.84, CI = 1.05-7.69), were less likely to be HER2/neu positive (OR = 0.22, CI = 0.08-0.61) and presented lower Ki67 expression (OR = 0.36, CI = 0.17-0.77). In addition, incident tumors presented a shorter survival time than did prevalent ones (RR = 4.88, CI = 1.12-21.19).ConclusionsIncident carcinomas include a variety of screen-detected carcinomas that exhibit differences in biology and prognosis relative to prevalent carcinomas. The detection method is important and should be taken into account when making therapy decisions

Institutional adoption and implementation of b-learning and its relationship with the self-perceived individual work performance of UPC faculty, in 2022

El objetivo de la presente investigación fue determinar si existe relación entre la adopción e implementación institucional de la modalidad b-learning en la UPC con el desempeño laboral individual autopercibido del personal que es parte de su plana docente. El diseño empleado para esta investigación es de base no experimental, de tipo transeccional y de alcance correlacional. La metodología utilizada para la recolección de información fue de enfoque cuantitativo. Para medir la percepción de los docentes de la UPC respecto de las dos variables materia de estudio, se elaboró y aplicó un cuestionario tipo Likert. La confiabilidad del referido instrumento fue definida mediante el Coeficiente de Alfa de Cronbach (0.905) y su validación fue concedida mediante el juicio de expertos en investigación. Se empleó la técnica de muestreo aleatorio simple para identificar una muestra de 174 docentes, de una población comprendida por 202 profesores a tiempo completo con experiencia en el dictado de cursos a distancia y blended, en los niveles de enseñanza de Pregrado y EPE. De acuerdo con los resultados obtenidos mediante la aplicación del Coeficiente de Correlación de Spearman (ρ = 0.668) y el Coeficiente de determinación (R2 = 0.512), se infiere la existencia de una relación directa y de intensidad fuerte entre la adopción e implementación institucional de la modalidad b-learning en la UPC y el desempeño laboral individual autopercibido de su plana docente, durante el 2022.The objective of this research is to determine if there is a relationship between institutional adoption and implementation of b-learning modality at the UPC with the self-perceived individual work performance of the faculty. The research design is non-experimental, transactional type and correlational scope. Likewise, quantitative approach methodology was used for data collection, therefore, regarding the two variables under study, a Likert-type survey was developed to measure the perception of UPC faculty. The reliability of the aforementioned instrument was defined by Cronbach's Alpha Coefficient (0.905) and its validation was granted through the judgment of research experts. A simple random sampling technique was used to recognize 174 teachers from a population comprised of 202 full-time teachers with experience on distance and blended courses, at the Undergraduate and EPE levels. According to Spearman's Correlation Coefficient (ρ = 0.668) and Determination Coefficient (R2 = 0.512), the existence of a direct and strong intensity relationship is inferred between the institutional adoption and implementation of b-learning modality in the UPC and the self-perceived individual work performance of the faculty, during 2022.Trabajo de investigació