Temporal behavior of Ethernet communications: impact of the operating system and protocol stack

Ethernet is currently the most widely used networking technology, spanning across many application domains including embedded systems. In this particular case, Ethernet is even used in many time-critical applications in which the delay induced by communication must be short and bounded. It is thus very important to understand the entire transmission process and assess its temporal behavior. There are a number of aspects to consider, including the network protocol, network topology, network elements and end devices. This paper aims at assessing the impact of the operating system and its protocol stack implementation in the end devices on the network temporal behavior. We studied four operating systems, namely a standard Ubuntu distribution with and without a real-time kernel patch, an embedded stripped down version of Linux and QNX Neutrino, and two hardware platforms, namely ordinary PCs and a single board computer based on an AVR32 CPU. We measured the Round Trip Delay (RTD) using RAW, UDP and TCP sockets to interface the protocol stack. We verified that on high computing power platforms the difference between the sockets is small but still significant in resource-constrained platforms. On the other hand, full featured general OSs present rather large worst-case delays. These can be reduced using real-time patches for those OSs, RTOSs, or even removing unnecessary modules, services and particularly, data intensive device drivers. We believe this study can be helpful for system designers as well as for teaching networks courses in embedded systems.Ethernet is currently the most widely used networking technology, spanning across many application domains including embedded systems. In this particular case, Ethernet is even used in many time-critical applications in which the delay induced by communication must be short and bounded. It is thus very important to understand the entire transmission process and assess its temporal behavior. There are a number of aspects to consider, including the network protocol, network topology, network elements and end devices. This paper aims at assessing the impact of the operating system and its protocol stack implementation in the end devices on the network temporal behavior. We studied four operating systems, namely a standard Ubuntu distribution with and without a real-time kernel patch, an embedded stripped down version of Linux and QNX Neutrino, and two hardware platforms, namely ordinary PCs and a single board computer based on an AVR32 CPU. We measured the Round Trip Delay (RTD) using RAW, UDP and TCP sockets to interface the protocol stack. We verified that on high computing power platforms the difference between the sockets is small but still significant in resource-constrained platforms. On the other hand, full featured general OSs present rather large worst-case delays. These can be reduced using real-time patches for those OSs, RTOSs, or even removing unnecessary modules, services and particularly, data intensive device drivers. We believe this study can be helpful for system designers as well as for teaching networks courses in embedded systems

A MONITORIA COMO ESPAÇO DE FORMAÇÃO PARA A DOCÊNCIA: Contribuições da Disciplina de Morfologia do Português

Este trabalho apresenta a importância das atividades desenvolvidas por meio do Programa Institucional de Monitoria (PIM), realizadas no componente curricular Morfologia do Português, do curso de Letras de uma Universidade pública do Estado do Tocantins. Tem como objetivo refletir e discutir a relevância da monitoria como espaço inicial de formação para a docência, considerando o processo de ensino-aprendizagem. Nesse sentido, os resultados mostram que o aluno tem uma possibilidade a mais de aprender o conteúdo, de reforçar tudo aquilo que está sendo passado pelo professor e influência de maneira positiva na disciplina, fortalecendo o ensino e promovendo a interação entre a comunidade acadêmica.   PALAVRAS-CHAVE: PIM; Formação Docente;  Disciplina; Morfologia do Português.     ABSTRACT This work presents the importance of the activities developed through the Institutional Monitoring Program (PIM), carried out in the curricular component Morphology of Portuguese, of the course of Letters of a public University of the State of Tocantins. It aims to reflect and discuss the importance of monitoring as an initial training space for teaching, considering the teaching-learning process. In this sense, the results show that the student has one more possibility to learn the content, to reinforce everything that is being passed by the teacher and to influence positively in the discipline, strengthening the teaching and promoting the interaction between the academic community. KEYWORDS: PIM; Formation Teacher; Discipline; Morphology of Portuguese.   RESUMEN Este trabajo muestra la importancia de las actividades realizadas por el Programa de Monitoreo Institucional (PIM), celebrada en el componente curricular morfología portugués, por supuesto cartas de una Universidad pública del Estado de Tocantins. Tiene como objetivo reflexionar y discutir la importancia del monitoreo como espacio inicial de formación para la docencia, considerando el proceso de enseñanza-aprendizaje. En este sentido, los resultados muestran que el alumno tiene una posibilidad más de aprender el contenido, de reforzar todo lo que está pasando el profesor e influir positivamente en la disciplina, fortaleciendo la enseñanza y promoviendo la interacción entre la comunidad académica.   PALABRAS CLAVE: PIM; Formación docente; la disciplina; Morfología de los portugueses. &nbsp

Distribution-Based Categorization of Classifier Transfer Learning

Transfer Learning (TL) aims to transfer knowledge acquired in one problem, the source problem, onto another problem, the target problem, dispensing with the bottom-up construction of the target model. Due to its relevance, TL has gained significant interest in the Machine Learning community since it paves the way to devise intelligent learning models that can easily be tailored to many different applications. As it is natural in a fast evolving area, a wide variety of TL methods, settings and nomenclature have been proposed so far. However, a wide range of works have been reporting different names for the same concepts. This concept and terminology mixture contribute however to obscure the TL field, hindering its proper consideration. In this paper we present a review of the literature on the majority of classification TL methods, and also a distribution-based categorization of TL with a common nomenclature suitable to classification problems. Under this perspective three main TL categories are presented, discussed and illustrated with examples

Complexos de inclusão de fármacos com ciclodextrinas e cucurbiturilos. Aplicações farmacoterapêuticas

Esta monografia tem por objectivo analisar a contribuição da Química Supramolecular no desenvolvimento de aplicações farmacoterapêuticas. É apresentada uma revisão e é feita uma análise detalhada das propriedades e aplicações já existentes das ciclodextrinas e também de novos nano-contentores que possam ter estas aplicações no futuro, com destaque para os cucurbiturilos. A Química Supramolecular é o ramo da Química que se foca no estudo das interacções não covalentes. Segundo Jean-Marie Lehn, Prémio Nobel da Química em 1987, a Química Supramolecular é o campo da ciência que estuda os conceitos químicos, físicos e biológicos de espécies químicas de grande complexidade que se mantêm unidas e organizadas através de interacções não covalentes. Relacionado com a Química Supramolecular está o conceito drug delivery, o processo de administração de fármacos com finalidade terapêutica. Neste processo podem ser utilizados complexos moleculares que aprisionam um fármaco, protegendo-o e alterando o seu perfil de libertação, absorção, distribuição e eliminação. Desta forma o fármaco chega ao local de interesse de uma forma mais eficaz e segura. As Ciclodextrinas são estruturas da família dos ciclo-oligossacarídeos correntemente usadas nestas aplicações terapêuticas. Possuem uma cavidade relativamente apolar no seu interior, com a capacidade de encapsular componentes hidrofóbicos. O exterior é hidrofílico, sendo pois solúveis em água. Possuem baixa toxicidade, dependendo da via de administração. São usadas em aplicações farmacêuticas, nomeadamente como forma de melhorar a biodisponibilidade do fármaco. Os Cucurbiturilos são uma família de contentores moleculares que podem encapsular uma variedade de espécies catiónicas e neutras com alta afinidade. Por esta razão mostram grande potencial em drug delivery. Foram feitos vários estudos no sentido de avaliar a toxicidade e estabilidade destas moléculas transportadoras. Até agora todos os resultados apontam para um futuro promissor dos cucurbiturilos em aplicações farmacoterapêuticas

Effect of wood aging on wine mineral composition and 87Sr/86Sr isotopic ratio

The evolution of mineral composition and wine strontium isotopic ratio 87Sr/86Sr (Sr IR) during wood aging were investigated. A red wine was aged in stainless steel tanks with French oak staves (Quercus sessiliflora Salisb.), with three industrial scale replicates. Sampling was carried out after 30, 60, and 90 days of aging, and the wines were evaluated in terms of general analysis, phenolic composition, total polysaccharides, multielement composition, and Sr IR. Li, Be, Mg, Al, Sc, Ti, V, Mn, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Mo, Sb, Cs, Ba, Pr, Nd, Sm, Eu, Dy, Ho, Er, Yb, Lu, Tl, and Pb elements and 87Sr/86Sr were determined by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS) and Na, K, Ca, and Fe by flame atomic absorption spectrometry (FAAS). Two-way ANOVA was applied to assess wood aging and time effect on Sr IR and mineral composition. Wood aging resulted in significantly higher concentrations of Mg, V, Co, Ni, and Sr. At the end of the aging period, wine exhibited statistically identical Sr IR compared to control. Study suggests that wood aging does not affect 87Sr/86Sr, not precluding the use of this parameter for wine traceability purposesinfo:eu-repo/semantics/publishedVersio

Recolha robotizada de rolhas

Tese de mestrado integrado. Engenharia Electrónica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 201

Age‐related white matter hyperintensities and overactive bladder: a systematic review

© 2023 The Authors. Neurourology and Urodynamics published by Wiley Periodicals LLC. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Introduction: Age-related white matter hyperintensities (ARWMHs) on brain magnetic resonance imaging have been associated with lower urinary tract symptoms/dysfunction (LUTS/LUTD), namely overactive bladder (OAB) and detrusor overactivity. We aimed to systematically review existing data on the association between ARWMH and LUTS and which clinical tools have been used for this assessment. Materials and methods: We searched PubMed/MEDLINE, Cochrane Library, and clinicaltrials.gov (from 1980 to November 2021) and considered original studies reporting data on ARWMH and LUTS/LUTD in patients of both sexes aged 50 or above. The primary outcome was OAB. We calculated the unadjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for the outcomes of interest using random-effects models. Results: Fourteen studies were included. LUTS assessment was heterogeneous and mainly based on the use of nonvalidated questionnaires. Urodynamics assessment was reported in five studies. ARWMHs were graded using visual scales in eight studies. Patients with moderate-to-severe ARWMHs were more likely to present with OAB and urgency urinary incontinence (UUI; OR = 1.61; 95% CI: 1.05-2.49, p = 0.03), I2 = 21.3%) when compared to patients with similar age and absent or mild ARWMH. Discussion and conclusions: High-quality data on the association between ARWMH and OAB is scarce. Patients with moderate to severe ARWMH showed higher levels of OAB symptoms, including UUI, when compared to patients with absent or mild ARWMH. The use of standardized tools to assess both ARWMH and OAB in these patients should be encouraged in future research.info:eu-repo/semantics/publishedVersio

Fixos e fluxos do circuito inferior da economia: Uma análise a partir dos camelôs do bairro Centro de Mossoró-RN

O espaço geográfico contém fixos e fluxos, sendo os fixos materialidade e formas e os fluxos a dinâmica que lhes dá vida. O objetivo desse trabalho é analisar os fixos e fluxos do circuito inferior da economia em Mossoró a partir dos camelôs, agentes caracterizados, devido seu ponto territorial. Para realização do trabalho utilizou-se como base revisão bibliográfica no que diz respeito aos fixos e fluxos, circuitos da economia urbana e camelôs enquanto agentes da economia urbana. Em seguida desenvolveu-se o trabalho de pesquisas e entrevistas in loco, para entendimento de como esses agentes afetam e são afetados pela realidade urbana. A partir do estudo foram observadas diversas dificuldades encontradas por esses agentes devido à precariedade de seus fixos, que refletem na dificuldade de desenvolvimento de fluxos, fazendo com que esses agentes necessitem ocupar espaços com grande mobilidade de pessoas

Adhesion of an endodontic sealer to dentin and gutta-percha: shear and push-out bond strength measurements and SEM analysis

The use of an adequate method for evaluation of the adhesion of root canal filling materials provides more reliable results to allow comparison of the materials and substantiate their clinical choice. The aims of this study were to compare the shear bond strength (SBS) test and push-out test for evaluation of the adhesion of an epoxy-based endodontic sealer (AH Plus) to dentin and gutta-percha, and to assess the failure modes on the debonded surfaces by means of scanning electron microscopy (SEM). Three groups were established (n=7): in group 1, root cylinders obtained from human canines were embedded in acrylic resin and had their canals prepared and filled with sealer; in group 2, longitudinal sections of dentin cylinders were embedded in resin with the canal surface smoothed and turned upwards; in group 3, gutta-percha cylinders were embedded in resin. Polyethylene tubes filled with sealer were positioned on the polished surface of the specimens (groups 2 and 3). The push-out test (group 1) and the SBS test (groups 2 and 3) were performed in an Instron universal testing machine running at crosshead speed of 1 mm/min. Means (±SD) in MPa were: G1 (8.8±1.13), G2 (5.9±1.05) and G3 (3.8±0.55). Statistical analysis by ANOVA and Student's t-test (a=0.05) revealed statistically significant differences (p<0.01) among the groups. SEM analysis showed a predominance of adhesive and mixed failures of AH Plus sealer. The tested surface affected significantly the results with the sealer reaching higher bond strength to dentin than to gutta-percha with the SBS test. The comparison of the employed methodologies showed that the SBS test produced significantly lower bond strength values than the push-out test, was skilful in determining the adhesion of AH Plus sealer to dentin and gutta-percha, and required specimens that could be easily prepared for SEM, presenting as a viable alternative for further experiments