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Femtosecond laser micromachining study with multiple wavelengths in CVD diamond.
No full textDiamond is well known for its many remarkable mechanical, thermal, electric and optical properties. Among its remarkable characteristics, it also presents interesting nonlinear optical effects, thus being a highly desired material for many photonic devices. Therefore, femtosecond laser micromachining can be used as the processing method of such devices due to its high micron/sub-micron resolution. Thus, in this paper, the incubation effect (damage threshold fluence as a function of the number of applied fs-pulses) is studied at 1030, 515 and 343 nm with 216 fs pulses using the zero damage method. By implementing the exponential defect model, the incubation parameter was determined to be (0.14 ± 0.03) at 1030 nm, (0.3 ± 0.1) at 515 nm, and (0.13 ± 0.04) at 343 nm, which indicates that at 515 nm, fewer fs-pulses are necessary to reach the minimum damage fluence value. In addition, a theoretical model of the electron density formed by a single fs-pulse was used to determine the main light-absorption mechanism at 343 nm. Consequently, this work adds to the knowledge of fs-laser micromachining of CVD diamond from near IR to UV
Voice of minorities : the positive influence of diversity management mediated by organizational identification.
No full textObjetivo: Analisar a relação entre a gestão da diversidade, a identificação organizacional e o comportamento de voz das minorias nas organizações. Método/abordagem: Realizou-se uma survey junto a uma amostra composta por 288 trabalhadores da Mesorregião Metropolitana de Belo Horizonte, pertencentes a pelo menos um desses grupos minoritários: pretos, mulheres, idosos (60 anos ou mais), pessoas com deficiência e LGBTQIA+. Para análise dos dados coletados, empregou-se a técnica de Modelagem de Equações Estruturais. Contribuições teóricas/práticas/sociais: A contribuição da pesquisa reside no avanço que traz para a compreensão dos múltiplos benefícios decorrentes do adequado gerenciamento da diversidade e que estão ligados, especificamente, às atitudes e comportamentos das minorias no ambiente de trabalho. Originalidade/relevância: A pesquisa busca avançar nas discussões sobre a influência que as práticas que visam garantir o adequado gerenciamento da diversidade exercem sobre as atitudes e comportamentos dos profissionais que compõem as minorias sociais.Purpose: To analyze the relationship among diversity management, organizational identification and voice behavior of minorities in organizations. Design/methodology/approach: For data collection, a survey was carried out with a sample of 288 workers from the Metropolitan Mesoregion of Belo Horizonte, belonging to at least one of these minority groups: Black people, women, the elderly (over 60 years), people with disabilities and LGBTQIA+. For data analysis, the Structural Equation Modeling technique was used. Research, Practical & Social implications: The research's contribution resides in the advance it brings to the understanding of the multiple benefits arising from the proper management of diversity and which are linked, specifically, to the attitudes and behaviors of minorities in the work environment. Originality/value: The research seeks to advance discussions on the influence that practices that aim to ensure the proper management of diversity exert on the attitudes and behaviors of professionals who make up social minorities
Artistic atrategies in the Screendance Fôlego : slavery and necropolitics in Campinas (SP-Brazil).
No full textEste artigo investiga a videodança Fôlego (2018), cuja temática aborda a violência praticada contra os corpos negros na contemporaneidade. Para tal apreciação, este trabalho fez um breve panorama acerca da historicidade da escravidão no Brasil, em especial sobre a cidade de Campinas (SP), local de criação da obra, tendo como eixo norteador o conceito de necropolítica (Mbembe, 2016). Logo, o artigo discute o processo virtual de criação em videodança (Angeli, 2020), contribuindo para o debate acerca de diferentes territorialidades da cena e para as provocações político-sociais na dança.This article explores the screendance Fôlego (2018), whose theme addresses the violence practiced against black bodies in contemporary times. To that end, this work presents a brief overview about the historicity of slavery in Brazil, in particular, about the city of Campinas (SP), place of creation of the work, based on the concept of necropolitics (Mbembe, 2016). Therefore, the article discusses the virtual process of creation in screendance (Angeli, 2020), contributing to the debate about the different territorialities of the performance and the political and social provocations in dance
Uma formalização da lógica modal usando o assistente de provas Coq.
No full textPrograma de Pós-Graduação em Ciência da Computação. Departamento de Ciência da Computação, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto.A modelagem de determinados tipos de sistemas computacionais com a lógica clássica
possui fatores limitantes. Neste contexto, a apresentação de outros sistemas lógicos, como
a lógica modal, e a construção de uma biblioteca para o assistente de provas Coq tem
o intuito de auxiliar nesta tarefa e facilitar o uso para a verificação de propriedades
de sistemas. A semântica da lógica modal é representada pela semântica dos mundos
possíveis, onde existe uma relação de acessibilidade que conecta os mundos de um mo-
delo. Diferentes restrições impostas na relação de acessibilidade constroem sistemas da
lógica modal que auxiliam na representação de propriedades nas mais diversas áreas de
estudo. O desenvolvimento da biblioteca tem como objetivo sustentar a formalização de
propriedades de softwares e prová-los em Coq.The modelling of certain types of computational systems with classical logic includes
limiting factors. In this context, the presentation of other logical systems, such as modal
logic, and the construction of a library for the proof assistant Coq intents to help in
this work and facilitate usage on the verification of systems’ properties. The semantics
of modal logic is represented by the semantics of possible worlds, where there is an
accessibility relationship that connects the worlds of a model. Different restrictions
imposed on the accessibility relation build modal logic systems that help representation
of properties on a wide array of research areas. The libary development aims to held the
formalization of properties in softwares and prove them on Coq
Classificação automática de arritmias utilizando mapeamento de sinais de ECG em grafos e redes neurais convolucionais de grafos.
No full textPrograma de Pós-Graduação em Ciência da Computação. Departamento de Ciência da Computação, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto.Conforme a Organização Mundial da Saúde (OMS), as doenças cardíacas figuram como a
principal causa de morte em âmbito global. Embora muitas dessas condições possam ser
diagnosticadas antecipadamente, a incidência de casos segue em ascensão. Estimativas indi-
cam que mais de 75% dos casos ocorrem em países de baixa renda ou em desenvolvimento,
e 17,9 milhões de pessoas morreram de doenças cardíacas apenas em 2019, totalizando
32% das mortes globais. A persistência desse aumento de casos realça a necessidade de
novas abordagens que automatizem a detecção de arritmias em sinais de eletrocardiograma
(ECG). Na literatura, inúmeras técnicas de extração de características são utilizadas para
representar o ECG como séries temporais unidimensionais, com o intuito de classificar pa-
drões associados à arritmias. Notavelmente, abordagens baseadas em aprendizado profundo
(redes de convolução) têm obtido resultados impressionantes para tal tarefa. Entretanto,
abordagens baseadas em grafos e redes complexas foram recentemente investigadas como
alternativas para aprimorar o desempenho na detecção de arritmias, porém, ainda se
apresenta como um desafio mapear ou representar adequadamente sinais de ECG na forma
de grafos. Assim, este estudo explora a representação dos sinais de ECG em grafos por meio
do Visibility Graph (VG) e Vector Visibility Graph (VVG). Adicionalmente, utilizamos
a estrutura de grafo para a classificação de arritmias com Redes Neurais Convolucionais
de Grafos (Graph Convolutional Networks - GCNs). Experimentos envolvendo diferen-
tes arquiteturas de GCNs foram avaliados no conjunto de dados MIT-BIH, seguindo os
paradigmas inter-patient e intra-patient. Os resultados indicam que a representação dos
sinais de ECG por meio de VG e VVG é promissora, e que o VG provou ser mais eficiente
em comparação ao método VVG para as arquiteturas de GCNs exploradas. Em relação à
classe de batimentos ectópicos supraventriculares (S), os resultados evidenciam que no
paradigma inter-patient ainda há um grande desafio a ser superado. Arquiteturas mais
simples de GCNs tiveram melhores resultados do que as complexas, indicando que sua
simplicidade melhora a captura das características essenciais dos dados e evita ruídos.
Essas arquiteturas também são mais eficientes computacionalmente, o que é importante
em cenários de recursos limitados.According to the World Health Organization (WHO), cardiovascular diseases are the
leading cause of death globally. Although many of these conditions can be diagnosed
in advance, the incidence of cases continues to rise. Estimates indicate that over 75%
of cases occur in low-income or developing countries, and 17.9 million people died from
cardiovascular diseases in 2019 alone, accounting for 32% of global deaths. The persistence
of this increasing trend highlights the needs for new approaches that automate the
detection of arrhythmias in electrocardiogram (ECG) signals. In the literature, numerous
feature extraction techniques are used to represent the ECG as one-dimensional time
series, with the aim of classifying patterns associated with arrhythmias. Notably, deep
learning-based approaches (convolutional networks) have achieved impressive results for
this task. However, graph-based and complex network approaches have recently been
investigated as alternatives to improve performance in arrhythmia detection. Nonetheless,
mapping or appropriately representing ECG signals in the form of graphs still presents a
challenge. Thus, this study explores the representation of ECG signals as graphs through
the Visibility Graph (VG) and Vector Visibility Graph (VVG). Additionally, we explore
the graph structure for arrhythmia classification with Graph Convolutional Networks
(GCNs). Experiments involving different GCN architectures are evaluated on the MIT-BIH
dataset, following the inter-patient and intra-patient paradigms. The results indicate that
the representation of ECG signals through VG and VVG is promising, and VG has proven
to be more efficient compared to the VVG method for the explored GCN architectures.
Regarding supraventricular ectopic class beats (S), the results demonstrate that there
is still a significant challenge to overcome in the inter-patient paradigm. Simpler GCN
architectures yielded better results than complex ones, indicating that their simplicity
enhances capturing essential data features and avoids noise. These architectures are also
computationally more efficient, which is important in scenarios with limited resources
A study on the barriers that impact the adoption of Industry 4.0 in the context of Brazilian companies.
No full textPurpose – This research aims to evaluate the impact of barriers experienced by Brazilian companies in
adopting Industry 4.0 (I4.0).
Design/methodology/approach – As a methodological approach, the survey method was used, adopting
the use of the questionnaire for data collection. From the feedback of 99 companies (with an index of 80%),
quantitative analyzes of the data were carried out with the aid of factor analysis and linear regression to
validate the proposed structural model.
Findings – The barriers construct does not impact the I4.0 adoption construct. Directly evaluating the effect of
the variables that make up the barriers construct in the I4.0 adoption construct, it was observed that three
barriers affect effectively the adoption of I4.0: technological infrastructure; financial constraint and lack of
understanding of the benefits of I4.0.
Research limitations/implications – As a limitation, the research was conducted only in the Brazilian
context, requiring the development of future studies in other countries that can strengthen the findings of this
research.
Practical implications – In addition, the results achieved provide relevant insights into public policymakers
and business managers, helping them to deeply understand the barriers that impact the adoption of I4.0. This
facilitates the propagation of I4.0 concepts in the context of Brazilian companies and in the formulation of
public policies adapted to each sector, allowing a more assertive action in the face of the types of barriers
experienced by organizations during the adoption of I4.0.
Social implications – The findings can help practitioners and policymakers to understand in detail this new
industrial model and the difficulties that prevent its implementation.
Originality/value – From an extensive literature review, no studies were identified that statistically validate
which barriers effectively affect the adoption of I4.0. This research is a pioneer in proposing a structural model
to analyze the barriers experienced by workers during the adoption of I4.0, exploring Brazilian companies, from
different economic sectors and sizes. It is noteworthy that the literature still focuses efforts on manufacturing
companies
Intelligent drone swarms to search for victims in post-disaster areas.
No full textThis study presents the Drone Swarms Routing Problem (DSRP), which consists of identify-
ing the maximum number of victims in post-disaster areas. The post-disaster area is modeled in a
complete graph, where each search location is represented by a vertex, and the edges are the shortest
paths between destinations, with an associated weight, corresponding to the battery consumption to
fly to a location. In addition, in the DSRP addressed here, a set of drones are deployed in a cooperative
drone swarms approach to boost the search. In this context, a V-shaped formation is applied with
leader replacements, which allows energy saving. We propose a computation model for the DSRP
that considers each drone as an agent that selects the next search location to visit through a simple
and efficient method, the Drone Swarm Heuristic. In order to evaluate the proposed model, scenarios
based on the Beirut port explosion in 2020 are used. Numerical experiments are presented in the
offline and online versions of the proposed method. The results from such scenarios showed the
efficiency of the proposed approach, attesting not only the coverage capacity of the computational
model but also the advantage of adopting the V-shaped formation flight with leader replacements
Nanoemulsion of Ocotea indecora (Shott) Mez essential oil : larvicidal effects against Aedes aegypti .
No full textThe widespread use of insecticide can lead to the resistance of the Aedes aegypti mosquito and adverse effects on
non-target organisms, such as humans, other animals, and insects. In this sense, nanotechnology associated with
natural products is a promising alternative to obtaining safer and more sustainable insecticide formulations
against this vector. Therefore, in this research, we developed and optimized a nanoemulsion with essential oil
from Ocotea indecora (Shott) Mez leaves and evaluated its larvicidal properties against Ae. aegypti larvae. In
addition, oral toxicity assays were performed to test the nanoemulsion safety of the non-target organism Apis
mellifera. The major constituent found was sesquirosefuran (81.4 %). The nanoemulsions were prepared by the
low-energy method by phase inversion and characterized by the dynamic light scattering technique. The most
suitable surfactant mixture was in hydrophilic-lipophilic balance 14.22, presenting droplets size of 122.8 nm and
polydispersity index of 0.262. Then a 23 factorial design was realized to optimize the formulation suggesting the
variables conditions of 1:1 of essential oil (5 % w/w) and surfactants at 500 rotations per minute. This led to
spherical nanoemulsions with mean size and PdI of 105.3 nm and 0.263, respectively. The optimized nano-
emulsion presented stability when stored at room temperature and refrigerated for up to one year. The LC50
values against Ae. aegypti larvae were 61.4, and 26.8 μg/mL after, 48, and 144 h, respectively. Scanning electron
micrography showed morphological body alterations on the larvae Ae. aegypti treated with the nanoemulsion.
Regarding the ecotoxicological evaluation, the nanoemulsion showed no toxicity against Apis mellifera. There-
fore, this work demonstrated a simple method to obtain O. indecora nanoemulsion as an environmental-friendlier
alternative to the Aedes aegypti control
Localização de mamógrafos : um estudo de caso para novos investimentos em Rondônia.
No full textO acesso a mamografia é diretriz estruturante do cuidado às mulheres no diagnóstico precoce do câncer de mama, devendo estar acessível a 60 km, no máximo, no Brasil. No entanto, essa não é a realidade para parte da população brasileira. Neste trabalho, trata-se o problema de localização de mamógrafos no Sistema Público de Saúde do Estado de Rondônia. O objetivo foi desenvolver dois modelos logísticos de localização baseados no acesso para maximizar a cobertura de exames, minimizar o número de equipamentos a serem adquiridos e a distância do atendimento. Os modelos se diferem pelo atendimento parcial ou total de uma localidade. Foram analisados vários cenários e os resultados mostraram que, com os modelos propostos e a utilização das atuais microrregiões de saúde, as soluções obtidas possibilitam uma distribuição espacial dos mamógrafos mais equilibrada e acessível, com aumento quantitativo e geográfico da cobertura de exames
Home office from the workers' perspective : lessons from the pandemic period.
No full textA presente pesquisa teve como objetivo levantar as percepções dos trabalhadores que passaram a realizar
suas atividades laborais em home office durante a pandemia do Covid-19, bem como suas expectativas
relativas ao período pós-pandêmico. Para esse fim, realizaram-se dez entrevistas em profundidade com
teletrabalhadores de diferentes setores de atuação. Optou-se pela aplicação da técnica de Análise de
Conteúdo para tratamento dos dados coletados. Examinando os resultados alcançados, verificou-se que
a ruptura repentina e desestruturada do modelo de trabalho presencial, seguida pela adoção do home
office, apesar de justificada devido ao avanço da pandemia, criou diversas dificuldades para os
trabalhadores entrevistados, especialmente no que se refere à conciliação das demandas pessoais e
profissionais. Complementarmente, constatou-se também que os participantes da pesquisa, devido à
ausência de uma divisão clara, tanto física quanto temporal, entre a vida pessoal e o trabalho, passaram
a estender a jornada laboral diária com frequência, o que os levou a um estado de esgotamento e estresse.
Apesar dessas dificuldades, os entrevistados se mostraram favoráveis à permanência do home office
mesmo após o fim da pandemia, demonstrando, em sua maioria, a preferência pelo modelo híbrido de
trabalho. Este estudo contribui para a discussão acerca da necessidade de planejar adequadamente a
migração do trabalho presencial para o home office ou vice-versa, de modo que esse processo ocorra de
maneira harmoniosa e organizada, evitando a insatisfação profissional dos trabalhadores envolvidos e
um eventual fracasso da adoção do teletrabalho.This research aimed to raise the perceptions of workers who started to perform their work activities at
home during the Covid-19 pandemic, as well as their expectations regarding the post-pandemic period.
For this purpose, ten in-depth interviews were carried out with teleworkers from different sectors of
activity. The Content Analysis technique was applied to analyze the collected data. Examining the
results achieved, it was found that the sudden and unstructured rupture of the presential work model,
followed by the adoption of the home office, despite being justified due to the advance of the pandemic,
created several difficulties for the workers interviewed, especially regarding the reconciliation of
demands personal and professional. In addition, it was also found that the research participants, due to
the absence of a clear division, both physical and temporal, between personal life and work, began to
extend their daily working hours frequently, which led them to a state of exhaustion and stress. Despite
these difficulties, respondents were favorable of maintaining the home office even after the end of the
pandemic, generally demonstrating their preference for the hybrid work model. This study contributes
to the discussion about the need to adequately plan the migration from presential work to the home office
or the inverse, ensuring that the process occurs in a harmonious and organized manner, avoiding
professional dissatisfaction of the workers involved and an eventual failure in the adoption of the
telecommuting