4,895 research outputs found
Artificial intelligence-based software (AID-FOREST) for tree detection: A new framework for fast and accurate forest inventorying using LiDAR point clouds
Forest inventories are essential to accurately estimate different dendrometric and forest stand parameters. However, classical forest inventories are time consuming, slow to conduct, sometimes inaccurate and costly. To address this problem, an efficient alternative approach has been sought and designed that will make this type of field work cheaper, faster, more accurate, and easier to complete. The implementation of this concept has required the development of a specifically designed software called "Artificial Intelligence for Digital Forest (AID-FOREST)", which is able to process point clouds obtained via mobile terrestrial laser scanning (MTLS) and then, to provide an array of multiple useful and accurate dendrometric and forest stand parameters. Singular characteristics of this approach are: No data pre-processing is required either pre-treatment of forest stand; fully automatic process once launched; no limitations by the size of the point cloud file and fast computations.To validate AID-FOREST, results provided by this software were compared against the obtained from in-situ classical forest inventories. To guaranty the soundness and generality of the comparison, different tree spe-cies, plot sizes, and tree densities were measured and analysed. A total of 76 plots (10,887 trees) were selected to conduct both a classic forest inventory reference method and a MTLS (ZEB-HORIZON, Geoslam, ltd.) scanning to obtain point clouds for AID-FOREST processing, known as the MTLS-AIDFOREST method. Thus, we compared the data collected by both methods estimating the average number of trees and diameter at breast height (DBH) for each plot. Moreover, 71 additional individual trees were scanned with MTLS and processed by AID-FOREST and were then felled and divided into logs measuring 1 m in length. This allowed us to accurately measure the DBH, total height, and total volume of the stems.When we compared the results obtained with each methodology, the mean detectability was 97% and ranged from 81.3 to 100%, with a bias (underestimation by MTLS-AIDFOREST method) in the number of trees per plot of 2.8% and a relative root-mean-square error (RMSE) of 9.2%. Species, plot size, and tree density did not significantly affect detectability. However, this parameter was significantly affected by the ecosystem visual complexity index (EVCI). The average DBH per plot was underestimated (but was not significantly different from 0) by the MTLS-AIDFOREST, with the average bias for pooled data being 1.8% with a RMSE of 7.5%. Similarly, there was no statistically significant differences between the two distribution functions of the DBH at the 95.0% confidence level.Regarding the individual tree parameters, MTLS-AIDFOREST underestimated DBH by 0.16 % (RMSE = 5.2 %) and overestimated the stem volume (Vt) by 1.37 % (RMSE = 14.3 %, although the BIAS was not statistically significantly different from 0). However, the MTLS-AIDFOREST method overestimated the total height (Ht) of the trees by a mean 1.33 m (5.1 %; relative RMSE = 11.5 %), because of the different height concepts measured by both methodological approaches. Finally, AID-FOREST required 30 to 66 min per ha-1 to fully automatically process the point cloud data from the *.las file corresponding to a given hectare plot. Thus, applying our MTLS-AIDFOREST methodology to make full forest inventories, required a 57.3 % of the time required to perform classical plot forest inventories (excluding the data postprocessing time in the latter case). A free trial of AID -FOREST can be requested at [email protected]
Improving Public Attitude towards Renewable Energy
In recent years, the urgent necessity and tremendous opportunity to accelerate the transition to a low-carbon competitive economy has resulted in growth of long-term targets for renewable energy and energy efficiency, which are coming from policy bodies worldwide. The inherent distributed nature of renewable energies, together with the modularity of those technologies, brings opportunities for consumer empowerment in terms of participation. Nevertheless, there is still the need for increasing global awareness and enabling policies, to strengthen the citizen role in the energy system, facilitating their proactive participation as renewable energy purchasers, investors, and clean energy producers. Drawing from research interviews and the academic literature, this article conceptualizes the understanding of the need for improving public attitudes and explores the factors influencing the acceptance in terms of misconceptions, best communication practices, activities addressing public concerns, and potential actions to bolster public support towards renewable energy. Research interviews were conducted at a technical workshop on social acceptance of renewable energy, held in Abu Dhabi in October 2013, and the findings show that despite detecting an increasing trend towards greater and more active participation of citizens, many misconceptions together with insufficient and inefficient awareness and communication initiatives on renewable energies persist. The main conclusions can be used as a basis for formulating sustainable energy ommunication and awareness campaigns in order to enhance public acceptance and increase active participation in renewable energy technologies.The authors would like to acknowledge the IRENA Secretariat and all of the experts who participated in the international technical workshop, and Stefan Ferris for his support in drafting. The authors would like to thank the Catalan Government for the quality accreditation 1537 given to their research group GREA (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia
Desempenho acadêmico de doutores egressos do Programa de Pós-Graduação em Medicina Ciências Médicas da Faculdade de Medicina da UFRGS
Introdução: embora, no Brasil, muito tenha sido feito para estimular a criação e manutenção de programas de pós-graduação ainda há carência de meios para avaliar e para mensurar a evolução profissional dos egressos. O objetivo é compreender a trajetória dos Doutores formados pelo Programa de Pós-Graduação em Medicina Ciências Médicas (PPGCM), Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS) e propor um índice de desempenho acadêmico e de inserção profissional. Métodos: foi realizado um estudo transversal. Foram coletados dados dos Currículos Lattes dos egressos de doutorado do Programa de Pós-Graduação em Medicina: Ciências Médicas (PPGCM), no período de 1987 a 2014. Foram extraídos apenas os dados pertinentes a sua origem, curso de graduação e de mestrado, produção intelectual, inserção acadêmica e a posição profissional. Resultados: foram analisados 324 doutores egressos, 221 eram graduados em Medicina. Foram utilizadas as variáveis: graduação em medicina, vínculo laboral em universidade pública, exerce atividade como orientador em nível de doutorado, exerce atividade como orientador em nível de mestrado, bolsista de produtividade em pesquisa do CNPq e possui registro do índice H no currículo Lattes. O coeficiente de determinação (R2) demonstrou que as variáveis incluídas no modelo explicam 99% do modelo hierárquico. Conclusão: os resultados demonstram que os egressos têm contribuído para a construção de conhecimento qualificado disseminado em jornais de circulação internacional, formação de recursos humanos, interagir e criar parcerias em seu ambiente de trabalho, gerenciar e repassar o conhecimento, bem como para fomentar o conhecimento na área das ciências médicas com relevância regional, nacional e internacional
The value of and challenges for cholera vaccines in Africa.
The 21st century saw a shift in the cholera burden from Asia to Africa. The risk factors for cholera outbreaks in Africa are incompletely understood, and the traditional emphasis on providing safe drinking water and improving sanitation and hygiene has proven remarkably insufficient to contain outbreaks. Current killed whole-cell oral cholera vaccines (OCVs) are safe and guarantee a high level of protection for several years. OCVs have been licensed for >20 years, but their potential for preventing and control cholera outbreaks in Africa has not been realized. Although each item in the long list of technical reasons why cholera vaccination campaigns have been deferred is plausible, we believe that the biggest barrier is that populations affected by cholera outbreaks are underprivileged and lack a strong political voice. The evaluation and use of OCVs as a tool for cholera control will require a new, more compassionate, less risk-averse generation of decision makers
A specific loop in human DNA polymerase mu allows switching between creative and DNA-instructed synthesis
Human DNA polymerase mu (Polμ) is a family X member that has terminal transferase activity but, in spite of a non-orthodox selection of the template information, displays its maximal catalytic efficiency in DNA-templated reactions. As terminal deoxynucleotidyl transferase (TdT), Polμ has a specific loop (loop1) that could provide this enzyme with its terminal transferase activity. When loop1 was deleted, human Polμ lacked TdT activity but improved DNA-binding and DNA template-dependent polymerization. Interestingly, when loop1 from TdT was inserted in Polμ (substituting its cognate loop1), the resulting chimaera displayed TdT activity, preferentially inserting dGTP residues, but had a strongly reduced template-dependent polymerization activity. Therefore, a specialized loop in Polμ, that could adopt alternative conformations, appears to provide this enzyme with a dual capacity: (i) template independency to create new DNA information, in which loop1 would have an active role by acting as a ‘pseudotemplate’; (ii) template-dependent polymerization, in which loop1 must allow binding of the template strand. Recent in vivo and in vitro data suggest that such a dual capacity could be advantageous to resolve microhomology-mediated end-joining reactions
The short term debt vs. long term debt puzzle: a model for the optimal mix
This paper argues that the existing finance literature is inadequate with respect to its coverage of capital structure of small and medium sized enterprises (SMEs). In particular it is argued that the cost of equity (being both conceptually ill defined and empirically non quantifiable) is not applicable to the capital structure decisions for a large proportion of SMEs and the optimal capital structure depends only on the mix of short and long term debt. The paper then presents a model, developed by practitioners for optimising the debt mix and demonstrates its practical application using an Italian firm's debt structure as a case study
First Results from the TOTEM Experiment
The first physics results from the TOTEM experiment are here reported,
concerning the measurements of the total, differential elastic, elastic and
inelastic pp cross-section at the LHC energy of = 7 TeV, obtained
using the luminosity measurement from CMS. A preliminary measurement of the
forward charged particle distribution is also shown.Comment: Conference Proceeding. MPI@LHC 2010: 2nd International Workshop on
Multiple Partonic Interactions at the LHC. Glasgow (UK), 29th of November to
the 3rd of December 201
Diamond Detectors for the TOTEM Timing Upgrade
This paper describes the design and the performance of the timing detector
developed by the TOTEM Collaboration for the Roman Pots (RPs) to measure the
Time-Of-Flight (TOF) of the protons produced in central diffractive
interactions at the LHC. The measurement of the TOF of the protons allows the
determination of the longitudinal position of the proton interaction vertex and
its association with one of the vertices reconstructed by the CMS detectors.
The TOF detector is based on single crystal Chemical Vapor Deposition (scCVD)
diamond plates and is designed to measure the protons TOF with about 50 ps time
precision. This upgrade to the TOTEM apparatus will be used in the LHC run 2
and will tag the central diffractive events up to an interaction pileup of
about 1. A dedicated fast and low noise electronics for the signal
amplification has been developed. The digitization of the diamond signal is
performed by sampling the waveform. After introducing the physics studies that
will most profit from the addition of these new detectors, we discuss in detail
the optimization and the performance of the first TOF detector installed in the
LHC in November 2015.Comment: 26 pages, 18 figures, 2 tables, submitted for publication to JINS
LHC Optics Measurement with Proton Tracks Detected by the Roman Pots of the TOTEM Experiment
Precise knowledge of the beam optics at the LHC is crucial to fulfil the
physics goals of the TOTEM experiment, where the kinematics of the scattered
protons is reconstructed with the near-beam telescopes -- so-called Roman Pots
(RP). Before being detected, the protons' trajectories are influenced by the
magnetic fields of the accelerator lattice. Thus precise understanding of the
proton transport is of key importance for the experiment. A novel method of
optics evaluation is proposed which exploits kinematical distributions of
elastically scattered protons observed in the RPs. Theoretical predictions, as
well as Monte Carlo studies, show that the residual uncertainty of this optics
estimation method is smaller than 0.25 percent.Comment: 20 pages, 11 figures, 5 figures, to be submitted to New J. Phy
- …