664 research outputs found
Polymer-based shielding approaches as a practical solution reducing radiological risks in field operations
The objective of this research is to evaluate various polymeric materials that have the potential to serve as substitutes or supplements to heavy vehicle structures for radiation-intensive environments. The materials under investigation include Nylon 6 (PA-6, C6H11NO), polyethylene (PE, C2H4), polypropylene (PP, C3H6), polyvinyl chloride (PVC, C2H3Cl), and polymethylacrylate (PMMA, C5H8O2). This study's primary aim is to determine each material's effectiveness in shielding against radiation and reducing exposure to vehicle occupants. As a new approach, this research examines the impact of utilizing polymeric materials and the potential health hazards for young drivers of both sexes, such as developing solid cancers from radiation exposure. According to the study, PVC was the most efficient polymer with a Transmission Factor (TF) of 0.44, leading to a 56% decrease in the relative risk estimate for the maximum thickness evaluated (20 cm). On the other hand, PP was identified as the least efficient, with a TF of 0.65, resulting in a 35% reduction in the relative risk estimate for the same thickness. The study concludes that each polymer has varying degrees of attenuation and that combining their properties is essential to achieving the desired level of risk reduction
A Review on Deep Learning in UAV Remote Sensing
Deep Neural Networks (DNNs) learn representation from data with an impressive
capability, and brought important breakthroughs for processing images,
time-series, natural language, audio, video, and many others. In the remote
sensing field, surveys and literature revisions specifically involving DNNs
algorithms' applications have been conducted in an attempt to summarize the
amount of information produced in its subfields. Recently, Unmanned Aerial
Vehicles (UAV) based applications have dominated aerial sensing research.
However, a literature revision that combines both "deep learning" and "UAV
remote sensing" thematics has not yet been conducted. The motivation for our
work was to present a comprehensive review of the fundamentals of Deep Learning
(DL) applied in UAV-based imagery. We focused mainly on describing
classification and regression techniques used in recent applications with
UAV-acquired data. For that, a total of 232 papers published in international
scientific journal databases was examined. We gathered the published material
and evaluated their characteristics regarding application, sensor, and
technique used. We relate how DL presents promising results and has the
potential for processing tasks associated with UAV-based image data. Lastly, we
project future perspectives, commentating on prominent DL paths to be explored
in the UAV remote sensing field. Our revision consists of a friendly-approach
to introduce, commentate, and summarize the state-of-the-art in UAV-based image
applications with DNNs algorithms in diverse subfields of remote sensing,
grouping it in the environmental, urban, and agricultural contexts.Comment: 38 pages, 10 figure
Abordagem estatĂstica dos acidentes de trĂąnsito fatais ocorridos em rodovia federal do Estado do ParĂĄ
Acidentes com vĂtimas fatais no trĂąnsito Ă© um problema de segurança pĂșblica que ganha cada vez mais destaque nas açÔesdo poder pĂșblico. Neste contexto, o objetivo do presente artigo Ă© proporcionar subsĂdios (dados) que orientem a tomadade decisĂŁo, contribuindo para a redução dos casos de acidentes de trĂąnsito com vĂtimas fatais, com base em fatos e dados.Para tanto, utilizou-se a tĂ©cnica estatĂstica AnĂĄlise ExploratĂłria de Dados, a partir da qual foi possĂvel verificar, entre outrosresultados, que a maioria dos acidentes que acontecem ao longo da rodovia federal BR-316 ocorre nos quilĂŽmetros iniciais,em pista de mĂŁo dupla e de traçado reto, sendo que as vĂtimas na maior parte dos casos sĂŁo os prĂłprios condutores deveĂculos e os acidentes fatais acometem, em sua maioria, homens na faixa etĂĄria de 25 a 29 anos
Counting and Locating High-Density Objects Using Convolutional Neural Network
This paper presents a Convolutional Neural Network (CNN) approach for
counting and locating objects in high-density imagery. To the best of our
knowledge, this is the first object counting and locating method based on a
feature map enhancement and a Multi-Stage Refinement of the confidence map. The
proposed method was evaluated in two counting datasets: tree and car. For the
tree dataset, our method returned a mean absolute error (MAE) of 2.05, a
root-mean-squared error (RMSE) of 2.87 and a coefficient of determination
(R) of 0.986. For the car dataset (CARPK and PUCPR+), our method was
superior to state-of-the-art methods. In the these datasets, our approach
achieved an MAE of 4.45 and 3.16, an RMSE of 6.18 and 4.39, and an R of
0.975 and 0.999, respectively. The proposed method is suitable for dealing with
high object-density, returning a state-of-the-art performance for counting and
locating objects.Comment: 15 pages, 10 figures, 8 table
ESTIMATIVA DA BIOMASSA DE CAFEEIROS EM SISTEMAS AGROFLORESTAIS SOB MANEJO ORGĂNICO E CONVENCIONAL EM DIFERENTES ARRANJOS
Nowadays, environmental services related to agroforestry systems are based on qualitative status. However, to occur the consolidation of payment of environmental services (PSE), factors that conditioning SAFs must be characterized. This study was carried out to evaluate if the individual biomass of coffee plants is affect by AFs characterized by distinctive management and design of Arabic coffee plants and grevilleas, in addition to checking the possibility of adjustment of allometric equations to estimate coffee dried biomass. The assay was carried out at coffee fields (Coffea arabica L.) associated with grevilleas (Grevillea robusta A. Cunn.) under conventional and organic management, situated at Planalto da Conquista and Chapada Diamantina, Bahia. From the biomass determination by destructive method of simple separation, estimation equations of individual biomass of coffee plants were established. It was concluded that the management system conventional or organic have minor impact to carbon and biomass accumulation when compared to coffee plants density and grevillea arrangement. The lower coffee plant density is a factor that determine the superiority of individual biomass stocks. Coffee plants density and grevillea arrangement are factor that determine different allometric models to coffee plants biomass estimation.Atualmente, os serviços ambientais relativos aos sistemas agroflorestais (SAFs) estĂŁo fundamentados em aspectos qualitativos. Entretanto, para que ocorra a consolidação do pagamentos por tais serviços, os diversos fatores que condicionam os SAFs necessitam ser caracterizados. Este estudo teve comoobjetivos analisar se o estoque de biomassa individual de cafeeiros Ă© afetado porSAFs caracterizados por manejo e arranjos distintos dos cafeeiros arĂĄbica e das grevĂleas, alĂ©m de verificar se haveria possibilidade de ajuste de equaçÔes alomĂ©tricas para estimar a biomassa seca dos cafeeiros.O experimento foi conduzido em sistemas de cultivo de cafĂ© (Coffea arabica L.) sob manejo orgĂąnico e convencional arborizado por grevĂleas (Grevillea robusta A. Cunn.), localizados nas regiĂ”es do Planalto da Conquista e Chapada Diamantina, Bahia. A partir da determinação da biomassa pelo mĂ©todo destrutivo da simples separação, foram estabelecidas equaçÔes de estimativa do estoque de biomassa individual dos cafeeiros. Concluiu-se que o sistema de manejo orgĂąnico e convencional sĂŁo fatores de menor impacto para o acĂșmulo de biomassa e carbono em relação Ă fatores como a densidade de cafeeiros e o arranjo das grevĂleas. O menor adensamento de cafeeiros Ă© fator que determina a superioridade dos estoques de biomassa individual.A densidade de cafeeiros e arranjo das grevĂleas sĂŁo fatores que determinam modelos alomĂ©tricos diferenciados para a estimativa de biomassa dos cafeeiros
AS CAUSAS DOS HOMICĂDIOS EM PERNAMBUCO- CONTRASTANDO A NARRATIVA OFICIAL E A EXPERIĂNCIA DA POPULAĂĂO
ApĂłs um perĂodo de forte queda iniciado em 2007, em paralelo com a implantação do Pacto Pela Vida, os Ăndices oficiais de homicĂdio de Pernambuco tem experimentado um notĂĄvel aumento a partir do ano de 2014. Segundo relatĂłrios e declaraçÔes da Secretaria de Defesa Social (SDS) do Governo do Estado, a maior parte desses crimes ocorre entre presidiĂĄrios, ex-presidiĂĄrios e membros do crime organizado, especialmente traficantes de drogas. Isso contradiz os achados de diversos estudos acerca dos mecanismos e processos psicossociais subjacentes aos crimes violentos letais no Nordeste e em Pernambuco, a maior parte dos quais tende a apontar uma "cultura da honra" e uma ausĂȘncia de governo como as principais causas. Tem-se ainda o fato de existir uma notĂłria falta de transparĂȘncia e acesso quanto aos dados acerca dos homicĂdios no estado. Dado tudo isso, o presente trabalho propĂ”e-se a identificar o perfil das vĂtimas e autores dos homicĂdios na RegiĂŁo Metropolitana do Recife, incluindo as circunstĂąncias e motivos de tais crimes e sua relevĂąncia, a partir das vivĂȘncias diretas da população, ou seja, suas experiĂȘncias com a ocorrĂȘncia de homicĂdio de membro da famĂlia, de pessoa conhecida fora da famĂlia e com o contato pessoal com autor de homicĂdio. A partir de uma anĂĄlise estatĂstica dos dados oriundos da aplicação de um questionĂĄrio a um total de 608 respondentes da RegiĂŁo Metropolitana do Recife, foram obtidos resultados apontando que: (a) a grande maioria das vĂtimas nĂŁo tinha histĂłrico prisional, (b) a grande maioria dos homicĂdios nĂŁo envolvia qualquer atividade criminal da parte da vĂtima ou do autor, inclusive qualquer relação com o narcotrĂĄfico, (c) na grande maioria dos homicĂdios, a vĂtima nĂŁo fez por merecer o crime realizado contra ela, (d) o perfil das vĂtimas era de uma vasta maioria do sexo masculino, idade entre 15 e 44 anos, com quase metade dos crimes envolvendo disputas pessoais e outros elementos nĂŁo criminais, (e) os homicĂdios em Pernambuco sĂŁo tidos pela população como sendo um problema social bastante grave e mal resolvido pelo governo estadual. Esses achados levam a concluir que o discurso oficial do Governo de Pernambuco acerca dos homicĂdios no estado Ă© inconsistente com a experiĂȘncia da população e consistentes com estudos anteriores acerca do assunto. Ao final, sĂŁo apresentadas implicaçÔes e sugestĂ”es.
Palavras Chave: HomicĂdios, Pernambuco, Criminologia, Cultura da Honra, NarcotrĂĄfic
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in âs = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fbâ1 of protonâproton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Observation of associated near-side and away-side long-range correlations in âsNN=5.02ââTeV proton-lead collisions with the ATLAS detector
Two-particle correlations in relative azimuthal angle (ÎÏ) and pseudorapidity (Îη) are measured in âsNN=5.02ââTeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1ââÎŒb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Îη|<5) ânear-sideâ (ÎÏâŒ0) correlation that grows rapidly with increasing ÎŁETPb. A long-range âaway-sideâ (ÎÏâŒÏ) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Îη and ÎÏ) and ÎŁETPb dependence. The resultant ÎÏ correlation is approximately symmetric about Ï/2, and is consistent with a dominant cosâĄ2ÎÏ modulation for all ÎŁETPb ranges and particle pT
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