Towards Reliable and Accurate Global Structure-from-Motion

Reconstruction of objects or scenes from sparse point detections across multiple views is one of the most tackled problems in computer vision. Given the coordinates of 2D points tracked in multiple images, the problem consists of estimating the corresponding 3D points and cameras\u27 calibrations (intrinsic and pose), and can be solved by minimizing reprojection errors using bundle adjustment. However, given bundle adjustment\u27s nonlinear objective function and iterative nature, a good starting guess is required to converge to global minima. Global and Incremental Structure-from-Motion methods appear as ways to provide good initializations to bundle adjustment, each with different properties. While Global Structure-from-Motion has been shown to result in more accurate reconstructions compared to Incremental Structure-from-Motion, the latter has better scalability by starting with a small subset of images and sequentially adding new views, allowing reconstruction of sequences with millions of images. Additionally, both Global and Incremental Structure-from-Motion methods rely on accurate models of the scene or object, and under noisy conditions or high model uncertainty might result in poor initializations for bundle adjustment. Recently pOSE, a class of matrix factorization methods, has been proposed as an alternative to conventional Global SfM methods. These methods use VarPro - a second-order optimization method - to minimize a linear combination of an approximation of reprojection errors and a regularization term based on an affine camera model, and have been shown to converge to global minima with a high rate even when starting from random camera calibration estimations.This thesis aims at improving the reliability and accuracy of global SfM through different approaches. First, by studying conditions for global optimality of point set registration, a point cloud averaging method that can be used when (incomplete) 3D point clouds of the same scene in different coordinate systems are available. Second, by extending pOSE methods to different Structure-from-Motion problem instances, such as Non-Rigid SfM or radial distortion invariant SfM. Third and finally, by replacing the regularization term of pOSE methods with an exponential regularization on the projective depth of the 3D point estimations, resulting in a loss that achieves reconstructions with accuracy close to bundle adjustment

Contactless smart screening in nursing homes : an IoT-enabled solution for the COVID-19 era

In the COVID-19 era, the provision of health indicators seamlessly and without contact, in groups at risk such as the elderly, is crucial due to the fast spread of the disease and the need to act quickly to contain its evolution. Continuous monitoring of vital signs, such as body temperature and cardio-respiratory rates, can be vital in early detection and prediction of COVID-19, which rapidly progresses and particularly affects the elderly population in nursing homes. Conventional clinical methods used for monitoring vital signs are contact-based, require contact sensors that need to be precisely attached by a trained health professional, are less convenient for repeatable measurements, and not practical for long-term monitoring. On the other hand, contactless vital signs monitoring using radar-based techniques, or IR-thermal imaging, do not require the attachment of physical electrodes and can be of great value in health screening of patients and help health professionals in early detection of the COVID-19 in the elderly population, in the specific context of nursing houses. This work describes the design and specification of a low-cost contactless health screening system for nursing homes, and includes the design of an IoT Edge device that can be placed above the beds where patients rest, allowing the continuous acquisition of health information and its processing without any type of contact and invasiveness.911A-2C18-106F | Carlos Jorge Enes Capit?o de AbreuN/

Um panorama te?rico/reflexivo sobre o programa etnomatem?tica.

Pretende-se, nesse artigo te?rico, abordar aspectos te?ricos que norteiam o Programa Etnomatem?tica. Inicialmente, o artigo traz a concep??o da raiz etimol?gica que fundamenta o termo Etnomatem?tica. Depois, destaca o reconhecimento da identidade cultural e da historicidade dos alunos, visando ? for- ma??o integral dos indiv?duos, o exerc?cio da cidadania e o est?mulo ao desenvolvimento da criatividade. Em seguida, apresenta algumas vis?es (filos?fica, pol?tica e pedag?gica) existentes de investigadores que possuem em rela??o ? concep??o do Programa Etnomatem?tica. Na sequ?ncia, relacionamos a teoria Lakatosiana como uma metodologia adequada para o Programa Etnomatem?tica. Por ?ltimo, abordamos a cultura na sala de aula de matem?tica e finalizamos com o curriculum trivium proposto por D?Ambrosio como uma resposta para indiv?duos preocupados com a coloniza??o de ideias matem?ticas.This article intends to address theoretical aspects that guide the Ethnomathematics Program. Initially, the article discusses the conception of the etymological root of the term Ethnomathematics. It then high- lights the recognition of the cultural identity and the historicity of the students, aiming at the integral development of the individuals, their ability to exercise citizenship, and the stimulus to the development of creativity. It then presents views (philosophical, political and pedagogical) of investigators who have in relation to their attention to the design of the Ethnomathematics Program. In the sequence, we relate the Lakatosian theory as an adequate methodology for the Ethnomathematics Program. Finally, we approach culture in the mathematics classrooms and we end with how the curriculum trivium proposed by D?Am- brosio is an answer to individuals who are concerned with colonization of mathematical ideas

SDRE APPLIED TO POSITION AND VIBRATION CONTROL OF A ROBOT MANIPULATOR WITH A FLEXIBLE LINK

This paper presents position and vibration control of a flexible robot composed of two rigid and one flexible links. Position is controlled by the current applied to the DC motor armature. To control vibrations of the flexible structure, Shape Memory Alloys (SMA) are used. Due to phase transformations, the SMA can change its stiffness through temperature variation, considering and taking advantage of this characteristic the vibration control is done. Control is achieved via the State Dependent Ricatti Equations (SDRE) technique, which uses suboptimal control and system local stability search. The simulation results show the feasibility of the proposed control for the considered system

Challenges for nerve repair using chitosan-siloxane hybrid porous scaffolds

The treatment of peripheral nerve injuries remains one of the greatest challenges of neurosurgery, as functional recover is rarely satisfactory in these patients. Recently, biodegradable nerve guides have shown great potential for enhancing nerve regeneration. A major advantage of these nerve guides is that no foreign material remains after the device has fulfilled its task, which spares a second surgical intervention. Recently, we studied peripheral nerve regeneration using chitosan-γ-glycidoxypropyltrimethoxysilane (chitosan-GPTMS) porous hybrid membranes. In our studies, these porous membranes significantly improved nerve fiber regeneration and functional recovery in rat models of axonotmetic and neurotmetic sciatic nerve injuries. In particular, the number of regenerated myelinated nerve fibers and myelin thickness were significantly higher in rat treated with chitosan porous hybrid membranes, whether or not they were used in combination with mesenchymal stem cells isolated from the Wharton’s jelly of the umbilical cord. In this review, we describe our findings on the use of chitosan-GPTMS hybrids for nerve regeneration

COMPACTION CAUSED BY FELLER-BUNCHER AND SKIDDER TRAFFIC IN AN ENTISOL UNDER DISTINCT MOISTURES

This research evaluated the influence of water content on soil compaction of an Entisol under traffic of forest harvesting machines and developed models to estimate soil compaction. The study was conducted in areas of a forest company, located in the state of Santa Catarina, Brazil. The sampling was performed under various conditions of soil moisture, contemplating three classes: Ug1 (Ug < 0,30 kg kg-1); Ug2 (0,30 64 Ug < 0,40 kg kg-1); Ug3 (Ug 65 0,40 kg kg-1). The soil bulk density was determined (Ds), total (Pt) and air-filled porosity (PA) and penetration resistance (RP), under the conditions without traffic (WT) and after traffic (AT) of a Feller-buncher (CAT 522) and a Skidder (CAT 545) employed in wood harvesting of Pinus taeda stands. Multiple regression equations were adjusted to estimate the soil penetration resistance, through arithmetic and logarithmic models with pure and mixed variables. The results indicate that in moisture condition above than 0,40 kg kg-1 (Ug3), the traffic promoted increase in Bd and PR of 10 and 24%, respectively, and decrease in \u3b1t and \u3b1air, in order of 12 and 43%. In low moisture content (Ug < 0,30 kg kg-1), the increase of Bd and PR was 3 and 13%, respectively, and the decrease of \u3b1air of 8% and without effect in \u3b1t. The stepwise logarithmic model with mixed variables (SLMM) showed the best results for the estimation of soil penetration resistance, but caution must be raised in their employment due to the possible influence of other factors in the estimation and determination of PR.Esta pesquisa objetivou avaliar a influencia da umidade na compactacao de um Neossolo Regolitico submetido ao trafego de maquinas de colheita florestal e desenvolver modelos para estimativa da compactacao. O trabalho foi conduzido em areas de uma empresa florestal localizada no Estado de Santa Catarina. A amostragem foi realizada em diversas condicoes de umidade do solo, contemplando tres classes: Ug1 (Ug < 0,30 kg kg-1); Ug2 (0,30 64Ug < 0,40 kg kg-1) e Ug3 (Ug 650,40 kg kg-1). Determinou-se a densidade do solo (Ds), a porosidade total (Pt) e de aeracao (PA) e a resistencia a penetracao (RP), nas condicoes sem trafego (ST) e apos trafego (AT) de um Feller buncher (CAT 522) e um Skidder (CAT 545) utilizados na colheita da madeira de povoamentos de Pinus taeda . Foram ajustadas equacoes de regressao multipla para estimar a RP, por meio de modelos aritmeticos e logaritmicos com variaveis puras e mistas. Os resultados indicaram que em condicao de umidade superior a 0,40 kg kg-1 (Ug3), o trafego promoveu aumento da Ds e RP da ordem de 10 e 24% e reducao da Pt e da PA, da ordem de 12 e 43%, respectivamente. Em baixa umidade (Ug < 0,30 kg kg-1), o aumento da Ds e RP foi da ordem de 3 e 13%, respectivamente, e reducao da PA da ordem de 8% e sem efeito na Pt. O modelo por stepwise logaritmico com variaveis mistas (MSLM) (Ln RP =-1,11 + 0,64Ds-2 + 0,14Ug-1) apresenta os melhores resultados para estimativa da resistencia do solo a penetracao, mas deve haver cautela no seu emprego, devido a possibilidade de influencia de outros fatores na estimativa e determinacao da RP

PHYSIOLOGICAL MATURATION OF Erythrina variegata L. SEEDS

O trabalho teve como objetivo estudar a matura\ue7\ue3o fisiol\uf3gica de sementes de Erythrina variegata L. Cada flor foi identificada em sua respectiva data de antese. A partir dos 21 dias ap\uf3s a antese (DAA) efetuaram-se coletas semanais de frutos para avalia\ue7\uf5es das seguintes caracter\uedsticas: comprimento e di\ue2metro dos frutos; colora\ue7\ue3o, massa fresca, massa seca e teor de \ue1gua de frutos e sementes; germina\ue7\ue3o e vigor das sementes. O delineamento experimental utilizado foi o inteiramente casualizado. O crescimento dos frutos de Erythrina variegata, em comprimento e di\ue2metro, vai at\ue9 42 DAA. As sementes come\ue7am a germinar aos 63 DAA, cujo teor de \ue1gua \ue9 de 68,15% e a massa seca 481,38 mg semente-1. A m\ue1xima germina\ue7\ue3o e vigor s\ue3o obtidos aos 77 DAA, que coincide com o m\ue1ximo conte\ufado de massa seca, frutos com colora\ue7\ue3o castanho-escura, sementes castanho-arroxeadas, com tegumento c\uf3rneo e teor de \ue1gua de 21%, considerado o ponto de matura\ue7\ue3o fisiol\uf3gica dessas sementes. Ap\uf3s 91 DAA ocorre a deisc\ueancia dos frutos.The study objective was to determine the physiological maturation of the Erythrina variegata L. seed. Each flower was identified according to its respective anthesis date. The fruit was collected weekly following the 21st day after anthesis (DAA). The following characteristics were evaluated: length and diameter of each fruit; color, fresh mass, dry mass, water content of both fruit and seeds; the seed germination state and vigor. The experimental design utilized was the completely randomized. It was found that the fruit of Erythrina variegata continues to grow in both length and diameter up until the 42ndDAA. The seeds start to germinate on the 63rd DAA, when the seed water content is 68.15% and the dry mass is 481.38 mg per seed. The maximum germination and vigor are obtained at the 77th DAA which coincides with the maximum seed dry mass. At this time the fruit has a dark brown color with brown-purple seeds which have a corneous tegument and a water content of 21%. This is considered as being the physiological maturation point of the seeds. The dehiscence of the fruit occurs at the 91st DAA

Semaphorin4A-Plexin D1 Axis Induces Th2 and Th17 While Represses Th1 Skewing in an Autocrine Manner

Semaphorin (Sema)4A is a transmembrane glycoprotein that is elevated in several autoimmune diseases such as systemic sclerosis, rheumatoid arthritis and multiple sclerosis. Sema4A has a key role in the regulation of Thelper Th1 and Th2 differentiation and we recently demonstrated that CD4(+) T cell activation induces the expression of Sema4A. However, the autocrine role of Sema4A on Th cell differentiation remains unknown. Naive Th cells from healthy controls were cell sorted and differentiated into Th1, Th2 and Th17 in the presence or absence of a neutralizing antibody against the Sema4A receptor PlexinD1. Gene expression was determined by quantitative PCR and protein expression by ELISA and flow cytometry. We found that the expression of Sema4A is induced during Th1, Th2 and Th17 differentiation. PlexinD1 neutralization induced the differentiation of Th1 cells, while reduced the Th2 and Th17 skewing. These effects were associated with an upregulation of the transcription factor T-bet by Th1 cells, and to downregulation of GATA3 and RORgammat in Th2 cells and Th17 cells, respectively. Finally, PlexinD1 neutralization regulates the systemic sclerosis patients serum-induced cytokine production by CD4(+) T cells. Therefore, the autocrine Sema4A-PlexinD1 signaling acts as a negative regulator of Th1 skewing but is a key mediator on Th2 and Th17 differentiation, suggesting that dysregulation of this axis might be implicated in the pathogenesis of CD4(+) T cell-mediated diseases

ENERGY USE OF WOOD RESIDUES IN PRODUCTION OF CERAMICS IN THE STATE OF SAO PAULO

O uso da biomassa florestal \ue9 uma importante alternativa de fonte energ\ue9tica renov\ue1vel, econ\uf4mica, t\ue9cnica e ambientalmente vi\ue1vel, disputando espa\ue7o com outras fontes energ\ue9ticas, mais caras ou n\ue3o renov\ue1veis, tais como g\ue1s natural, \uf3leo diesel e GLP. Dentro do setor industrial, maior consumidor de energia a partir de biomassa, destaca-se o segmento de cer\ue2micas vermelhas, tradicional consumidor de lenha para a produ\ue7\ue3o de energia. Uma consider\ue1vel parcela de empresas deste setor recentemente passou a utilizar, como alternativa de energia, cavacos produzidos a partir de res\uedduos madeireiros diversos. A op\ue7\ue3o por esse tipo de biomassa se deve a quatro principais raz\uf5es: maior disponibilidade desse material para aquisi\ue7\ue3o no mercado; envolver um importante aspecto ambiental, uma vez que se trata de um material de origem renov\ue1vel; por proporcionar uma maior homogeneidade durante a combust\ue3o, quando comparado com a lenha; e possibilita a automa\ue7\ue3o da alimenta\ue7\ue3o dos fornos. O presente estudo teve por objetivo caracterizar e descrever o segmento de cer\ue2micas vermelhas no Estado de S\ue3o Paulo quanto ao consumo de res\uedduos madeireiros para fins energ\ue9ticos. A pesquisa por amostragem coletou dados regionais sobre a quantidade e efici\ueancia do uso de res\uedduos madeireiros como fonte de gera\ue7\ue3o de energia no setor, bem como aspectos tecnol\uf3gicos, econ\uf4micos e log\uedsticos associados ao uso desta biomassa. Estima-se que o uso de cavacos de madeira vem sendo adotado atualmente por cerca de 80% das cer\ue2micas de porte m\ue9dio no Estado de S\ue3o Paulo. Os cavacos s\ue3o originados de res\uedduos de serrarias, opera\ue7\uf5es da colheita florestal de pinus e eucalipto, poda de arboriza\ue7\ue3o urbana e reciclagem de produtos madeireiros em geral. O raio m\ue9dio de dist\ue2ncia para suprimento dos cavacos at\ue9 as cer\ue2micas \ue9 de aproximadamente 200 km. As cer\ue2micas avaliadas compram os cavacos de terceiros a um pre\ue7o m\ue9dio em torno de R 43,00 por m\ub3. A efici\ueancia m\ue9dia apurada foi de 1,4 m\ub3 de cavaco para cada milheiro de pe\ue7as acabadas produzidas. As cer\ue2micas expressaram a necessidade de maior regularidade na qualidade deste biocombust\uedvel, que normalmente varia a cada carga recebida.The use of forest biomass is an important alternative source of renewable, economic, technical and environmentally viable energy, which struggles to displace other energy sources that are more expensive or non-renewable, such as natural gas, diesel oil and LPG. Within the industrial sector, which is the biggest consumer of energy from biomass, the red ceramics sector represents a traditional consumer of firewood for energy production. A considerable number of companies in this sector has recently started to use, as an alternative option for energy production, chips made from several different wood wastes. The choice for this type of biomass is due to four main reasons: high availability of material on the market; environmental benefits, since it is a renewable material; higher uniformity during combustion, compared with firewood; and feasibility for implementation of an automatic furnace feeding system. This study aimed to characterize and describe the red ceramics sector in the State of Sao Paulo, regarding the consumption of wood residues for energy purposes. The sampling survey collected regional data on the quantity and efficiency of use of wood residues as a source for energy generation in the sector, as well as on technological, economic and logistical aspects related to the use of this biomass. It is estimated that the use of wood chips is being presently adopted by approximately 80% of medium scale ceramic plants in the State of Sao Paulo. These chips are originated from sawmill residues, forest harvest operations of pine and eucalyptus, urban trees pruning and recycling of wood products in general. The average distance radius for supply of chips to the ceramic plants is approximately 200 km. The evaluated ceramic plants outsource chips at an average price of R 43.00 per m\ub3. The average efficiency observed was of 1.4 m\ub3 of chips per thousand finished pieces produced. The ceramic plants reported the need for a better regularity in quality of this bio-fuel, which usually varies for each other load delivered