On the Entropy of Oscillator-Based True Random Number Generators under Ionizing Radiation

The effects of ionizing radiation on field-programmable gate arrays (FPGAs) have been investigated in depth during the last decades. The impact of these effects is typically evaluated on implementations which have a deterministic behavior. In this article, two well-known true-random number generators (TRNGs) based on sampling jittery signals have been exposed to a Co-60 radiation source as in the standard tests for space conditions. The effects of the accumulated dose on these TRNGs, an in particular, its repercussion over their randomness quality (e.g., entropy or linear complexity), have been evaluated by using two National Institute of Standards and Technology (NIST) statistical test suites. The obtained results clearly show how the degradation of the statistical properties of these TRNGs increases with the accumulated dose. It is also notable that the deterioration of the TRNG (non-deterministic component) appears before that the degradation of the deterministic elements in the FPGA, which compromises the integrated circuit lifetime.Ministerio de Economía y Competitividad (ESP-2015-68245-C4-1-P)Ministerio de Economía y Competitividad (ESP-2015-68245-C4-4-P)Ministerio de Economía y Empresa (TIN2016-79095-C2-2-R)CAM (S2013/ICE-3095

Total Ionizing Dose Effects on a Delay-Based Physical Unclonable Function Implemented in FPGAs

Physical Unclonable Functions (PUFs) are hardware security primitives that are increasingly being used for authentication and key generation in ICs and FPGAs. For space systems, they are a promising approach to meet the needs for secure communications at low cost. To this purpose, it is essential to determine if they are reliable in the space radiation environment. In this work we evaluate the Total Ionizing Dose effects on a delay-based PUF implemented in SRAM-FPGA, namely a Ring Oscillator PUF. Several major quality metrics have been used to analyze the evolution of the PUF response with the total ionizing dose. Experimental results demonstrate that total ionizing dose has a perceptible effect on the quality of the PUF response, but it could still be used for space applications by making some appropriate corrections.Ministerio de Economía y Competitividad ESP2015-68245-C4-1-P, ESP-2015-68245-C4-4-P

Aedes ægypti control in urban areas: A systemic approach to a complex dynamic.

The available strategy for controlling the diseases transmitted by Aedes ægypti (dengue fever, Zika, and chikungunya) relies on continued community participation. Despite slogans emphasizing how easy it should be, no country has achieved it since the seventies. To better investigate potentially sustainable interventions, we developed a systemic model based on a multidisciplinary approach, integrating as deeply as possible specialized knowledge and field experience. The resulting model is composed of 4 external and 8 internal subsystems and 31 relationships, consistent with the literature and checked over multiple iterations with specialists of the many areas. We analyzed the model and the main feedback loops responsible for the system's stability, searching for possible interventions that could shift the existing balance. We suggest the introduction of 1 more player, the local primary health care structure, with the potential to change the undesired equilibrium. The health agents in the areas are the first to detect disease cases, and they could stimulate individuals to inform about potential mosquitoes' breeding sites and bring timely information to the vector-control program. Triggering such an action could introduce changes in people's attitude through a positive feedback loop in the desired direction

Implementación de mecanismos para lograr el cumplimiento del principio de probidad en las instituciones públicas

El presente trabajo de investigación tiene como finalidad analizar qué mecanismos se implementarán para lograr el cumplimiento del principio de probidad en las instituciones públicas. Se justifica debido a la existencia de intereses particulares por parte de funcionarios y servidores públicos, que no respetan los principios éticos, precisamente el principio de probidad que se viene vulnerando, por ello se van a proponer mecanismos que coadyuvaran a las instituciones públicas a reforzar un eficiente control y fiscalización permanente. El enfoque es cualitativo, tipo de investigación básica, diseño aplicado fenomenológico, técnica entrevista a profundidad, instrumento guía de entrevista conformada por 7 preguntas, se tuvo 6 participantes, herramienta de interpretación de datos se utilizó el Atlas Ti. Como resultado se obtuvo que el control realizado por el Estado deba apegarse a postulados de transparencia, honradez, integridad y espíritu de servicio. Se concluyó que los mecanismos por implementar para dar cumplimiento al principio de probidad son: La creación de herramientas tecnológicas del Estado que conllevaría al comienzo de una nueva gestión y disminución de riesgos; mejorar los filtros de contratación; incorporación de un área específica en las instituciones públicas, cuya finalidad sea dar cumplimiento a la ética e integridad en la función pública

Identifying and quantifying the abundance of economically important palms in tropical moist forest using UAV imagery

Sustainable management of non-timber forest products such as palm fruits is crucial for the long-term conservation of intact forest. A major limitation to expanding sustainable management of palms has been the need for precise information about the resources at scales of tens to hundreds of hectares, while typical ground-based surveys only sample small areas. In recent years, small unmanned aerial vehicles (UAVs) have become an important tool for mapping forest areas as they are cheap and easy to transport, and they provide high spatial resolution imagery of remote areas. We developed an object-based classification workflow for RGB UAV imagery which aims to identify and delineate palm tree crowns in the tropical rainforest by combining image processing and GIS functionalities using color and textural information in an integrative way to show one of the potential uses of UAVs in tropical forests. Ten permanent forest plots with 1170 reference palm trees were assessed from October to December 2017. The results indicate that palm tree crowns could be clearly identified and, in some cases, quantified following the workflow. The best results were obtained using the random forest classifier with an 85% overall accuracy and 0.82 kappa index.Publisher PDFPeer reviewe

Classificação das fraturas toracolombares: comparação entre as classificações de AO e Vaccaro

Objetivo: las clasificaciones han cambiado en el último medio siglo, la más usada desde la pasada década es la Clasificación AO. En 2004, Vaccaro et al. propusieron el Thoraco-Lumbar Injury Classification and Severity Score (TLICS). Métodos: análisis de la reproductividad inter y intra observador, utilizando el test Kappa, de las dos clasificaciones entre tres niveles distintos de traumatólogos en formación, en 30 casos. Resultados: la reproductividad intraobservador en la clasificación de Vaccaro fue: OI: 0,73; OII: 0,6 y OIII: 0,63. Para la clasificación AO: 0,7; 0,7 y 0,6, respectivamente. Entre las dos clasificaciones: OI: 0,59; OII: 0,7 y OIII: 0,62. La evaluación interobservador para la clasificación de Vaccaro es 0,66 y para la clasificación AO de 0,67. Los puntos críticos: rotación y lesiones del complejo ligamentario posterior. Conclusiones: las dos clasificaciones muestran un buen grado de acuerdo (índice de Kappa). Con la de Vaccaro, se observó un acuerdo global del 69%. Con respecto a la indicación de tratamiento ortopédico, el acuerdo fue el 37%. En la indicación de tratamiento quirúrgico, fue del 29%. Cabe remarcar que dicha clasificación dispone de un nivel impreciso donde se puede optar por cualquiera de los dos tratamientos (TLICS 4), esto se observó en el 3%. No hubo concordancia en el 31%. Las mismas indicaciones para la clasificación AO presentaron un acuerdo global del 67%. Para la indicación ortopédica fue del 32%. Se realizó una indicación quirúrgica en el 21%. En las lesiones clasificadas como A3 (14%), su indicación de tratamiento no es definida con unanimidad entre los observadores.Objective: the classifications have changed in the last half century; the most used from the last decade is Classification AO. In 2004, Vaccaro et al. proposed the Thoraco-Lumbar Injury Classification and Severity Score (TLICS). Methods: one analysis of the inter and intra observant reproduction by using the Kappa test, of the two classifications between three different levels from orthopedic surgeons in formation in 30 cases. Results: the intraobservant reproduction in the classification of Vaccaro was: OI: 0.73; OII: 0.6, and OIII: 0.63. For the AO classification: 0.7; 0.7 and 0.6, respectively. Between the two classifications: OI: 0.59; OII: 0.7, and OIII: 0.62. The interobservant evaluation for the classification of Vaccaro is 0.66 and for AO classification was 0.67. The tactically important points were rotation and injuries of the later ligamentary complex. Conclusions: the two classifications show a good degree in agreement (Kappa index). With the Vaccaro, it has been observed a global agreement of 69%. Regarding the indication of orthopedic treatment, the agreement was 37%. In the surgical treatment indication, it was 29%. It is possible to remark that this classification has a vague level where it can be decided on any of the two treatments (TLICS 4). This was observed in 3%. There was no agreement in 31%. The same indications for classification AO presented a global agreement of 67%. For the orthopedic indication, it was 32%. A surgical indication was made in 21%. In the injuries classified as A3 (14%) about the treatment is not defined with unanimity between the observers.Objetivo: as classificações têm mudado na último metade do século, sendo a mais usada desde a última década, a classificação AO. Em 2004, Vaccaro et al. propuseram a Thoraco-Lumbar Injury Classification (TLICS). Métodos: análise da reprodução inter e intraobservador, utilizando o teste Kappa das classificações entre três níveis distintos de traumatólogos em formação, em 30 casos. Resultados: a reprodução intraobservador na classificação de Vaccaro foi: OI: 0,73; OII: 0,6 e OIII: 0,63. Para a classificação AO, 0,77; 0,7 e 0,6, respectivamente. Entre as duas classificações: OI: 0,59; OII: 0,7 e OIII: 0,62. A avaliação interobservador para a classificação de Vaccaro foi de 0,66 e para a classificação AO de 0,67. Os pontos críticos foram rotação e lesões do complexo ligamentar posterior. Conclusões: as duas classificações mostram um bom grau de concordância (índice Kappa). Com a de Vaccaro, observou-se concordância global de 69%. Com respeito à indicação do tratamento ortopédico, a concordância foi de 37%. A indicação de tratamento cirúrgico foi de 29%. Cabe salientar que essa classificação dispõe de um nível impreciso em que pode-se optar por qualquer dos dois tratamentos (TLICS 4), o qual foi observado em 3%. Não houve concordância em 31%. As mesmas indicações para a classificação AO apresentaram concordância global de 67%. Indicação ortopédica foi de 32%. Foi realizada uma cirurgia em 21%. Nas lesões classificadas como A3 (14%), a sua indicação de tratamento não foi definida com unanimidade entre os observadores.Facultad de Ciencias Médica

Aboveground forest biomass varies across continents, ecological zones and successional stages: refined IPCC default values for tropical and subtropical forests

For monitoring and reporting forest carbon stocks and fluxes, many countries in the tropics and subtropics rely on default values of forest aboveground biomass (AGB) from the Intergovernmental Panel on Climate Change (IPCC) guidelines for National Greenhouse Gas (GHG) Inventories. Default IPCC forest AGB values originated from 2006, and are relatively crude estimates of average values per continent and ecological zone. The 2006 default values were based on limited plot data available at the time, methods for their derivation were not fully clear, and no distinction between successional stages was made. As part of the 2019 Refinement to the 2006 IPCC Guidelines for GHG Inventories, we updated the default AGB values for tropical and subtropical forests based on AGB data from >25 000 plots in natural forests and a global AGB map where no plot data were available. We calculated refined AGB default values per continent, ecological zone, and successional stage, and provided a measure of uncertainty. AGB in tropical and subtropical forests varies by an order of magnitude across continents, ecological zones, and successional stage. Our refined default values generally reflect the climatic gradients in the tropics, with more AGB in wetter areas. AGB is generally higher in old-growth than in secondary forests, and higher in older secondary (regrowth >20 years old and degraded/logged forests) than in young secondary forests (20 years old). While refined default values for tropical old-growth forest are largely similar to the previous 2006 default values, the new default values are 4.0-7.7-fold lower for young secondary forests. Thus, the refined values will strongly alter estimated carbon stocks and fluxes, and emphasize the critical importance of old-growth forest conservation. We provide a reproducible approach to facilitate future refinements and encourage targeted efforts to establish permanent plots in areas with data gaps