3,536 research outputs found
Traffic control for a swarm of robots:avoiding target congestion
One of the main problems in the navigation of robotic swarms is when several robots try to reach the same target at the same time, causing congestion situations that may compromise performance. In this paper, we propose a distributed coordination algorithm to alleviate this type of congestion. Using local sensing and communication, and controlling their actions using a probabilistic finite state machine, robots are able to coordinate themselves to avoid these situations. Simulations and real experiments were executed to study the performance and effectiveness of the proposed algorithm. Results show that the algorithm allows the swarm to have a more efficient and smoother navigation and is suitable for large groups of robots
Traffic control for a swarm of robots:avoiding group conflicts
A very common problem in the navigation of robotic swarms is when groups of robots move into opposite directions, causing congestion situations that may compromise performance. In this paper, we propose a distributed coordination algorithm to alleviate this type of congestion. By working collaboratively, and warning their teammates about a congestion risk, robots are able to coordinate themselves to avoid these situations. We executed simulations and real experiments to study the performance and effectiveness of the proposed algorithm. Results show that the algorithm allows the swarm to navigate in a smoother and more efficient fashion, and is suitable for large groups of robots
No robot left behind:coordination to overcome local minima in swarm navigation
In this paper, we address navigation and coordination methods that allow swarms of robots to converge and spread along complex 2D shapes in environments containing unknown obstacles. Shapes are modeled using implicit functions and a gradient descent approach is used for controlling the swarm. To overcome local minima, that may appear in these scenarios, we use a coordination mechanism that reallocates some robots as “rescuers” and sends them to help other robots that may be trapped. Simulations and real experiments demonstrate the feasibility of the proposed approach
O Antropoceno, a crise ambiental e as desigualdades no acesso a serviços e políticas de saúde
The interpretation of multiple embedded genitive constructions by Wapichana and English speakers
While research on Amazonian languages shows controversial data about the universality of recursive structures, researchers in language acquisition with Indo-European and East Asian languages have shown that complex recursive constructions are acquired very early by children. This study contributes to both debates about recursive structures in indigenous languages and the acquisition of recursion by children. We tested the comprehension of multiple embedded genitive constructions in Wapichana and English to answer two distinct questions: (1) Does the Wapichana grammar accept recursive genitives? (2) If yes, do Wapichana children acquire the multiple embedded genitives at a similar rate as English speaking children? Our data show that the interpretation of recursive genitives in English and Wapichana by adult speakers is exactly the same. Moreover, we show that both groups of children acquire multiple embedded genitives very early, but only achieve adult performance after the age of seven.While research on Amazonian languages shows controversial data about the universality of recursive structures, researchers in language acquisition with Indo-European and East Asian languages have shown that complex recursive constructions are acquired very early by children. This study contributes to both debates about recursive structures in indigenous languages and the acquisition of recursion by children. We tested the comprehension of multiple embedded genitive constructions in Wapichana and English to answer two distinct questions: (1) Does the Wapichana grammar accept recursive genitives? (2) If yes, do Wapichana children acquire the multiple embedded genitives at a similar rate as English speaking children? Our data show that the interpretation of recursive genitives in English and Wapichana by adult speakers is exactly the same. Moreover, we show that both groups of children acquire multiple embedded genitives very early, but only achieve adult performance after the age of seven
Schr\"odinger formalism for a particle constrained to a surface in
In this work it is studied the Schr\"odinger equation for a non-relativistic
particle restricted to move on a surface in a three-dimensional Minkowskian
medium , i.e., the space equipped with the
metric . After establishing the consistency of the
interpretative postulates for the new Schr\"odinger equation, namely the
conservation of probability and the hermiticity of the new Hamiltonian built
out of the Laplacian in , we investigate the confining
potential formalism in the new effective geometry. Like in the well-known
Euclidean case, it is found a geometry-induced potential acting on the dynamics
which, besides
the usual dependence on the mean () and Gaussian () curvatures of the
surface, has the remarkable feature of a dependence on the signature of the
induced metric of the surface: if the signature is ,
and if the signature is . Applications to surfaces of
revolution in are examined, and we provide examples where the
Schr\"odinger equation is exactly solvable. It is hoped that our formalism will
prove useful in the modeling of novel materials such as hyperbolic
metamaterials, which are characterized by a hyperbolic dispersion relation, in
contrast to the usual spherical (elliptic) dispersion typically found in
conventional materials.Comment: 26 pages, 1 figure; comments are welcom
Structure-activity relationships of hypervalent organochalcogenanes as inhibitors of cysteine cathepsins V and S
A new series of organotelluranes were synthesized and investigated, and the structure-activity relationships in cysteine proteases inhibition were determinated. It was possible to identify the relevance of structural components linked to the reactivity of these compounds as inhibitors. for example, dibromo-organotelluranes showed to be more reactive than dichloro-organotelluranes towards cysteine cathepsins V and S. Besides, no remarkable enantio-selectivity was verified. in general the achiral organotelluranes were more reactive than the chiral congeners against cysteine cathepsins V and S. A reactivity order for organochalcogenanes and cysteine cathepsins was proposed after the comparison of the inhibitory potencies of organotelluranes with the related organoselenanes. (C) 2011 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04044200 São Paulo, BrazilUniv São Paulo, Inst Quim, BR-05508900 São Paulo, BrazilUniv British Columbia, Dept Dent, Fac Dent, Vancouver, BC V6T 1Z3, CanadaUniv British Columbia, UBC Ctr Blood Res, Fac Dent, Vancouver, BC V6T 1Z3, CanadaUniv Fed ABC, CCNH, BR-09210580 Santo Andre, SP, BrazilUniversidade Federal de São Paulo, Dept Biofis, Escola Paulista Med, BR-04044200 São Paulo, BrazilWeb of Scienc
Truck Axle Detection with Convolutional Neural Networks
Axle count in trucks is important to the classification of vehicles and to
the operation of road systems, and is used in the determination of service fees
and the impact on the pavement. Although axle count can be achieved with
traditional methods, such as manual labor, it is increasingly possible to count
axles using deep learning and computer vision methods. This paper aims to
compare three deep learning object detection algorithms, YOLO, Faster R-CNN and
SSD, for the detection of truck axles. A dataset was built to provide training
and testing examples for the neural networks. Training was done on different
base models, to increase training time efficiency and to compare results. We
evaluated results based on three metrics: mAP, F1-score, and FPS count. Results
indicate that YOLO and SSD have similar accuracy and performance, with more
than 96% mAP for both models. Dataset and codes are publicly available for
download.Comment: Code and dataset available for donwload, links provide
Convergências entre planejamento de atenção primária à saúde e os Objetivos de Desenvolvimento Sustentável: uma avaliação de planos municipais de saúde do Brasil e Chile
This study explores the importance of Primary Health Care (PHC) for the achievement of the Sustainable Development Goals (SDGs), assessing the convergences between two PHC municipal agendas and the global Agenda 2030. For this purpose, the PHC actions included in the municipal health plans of Santiago, Chile, and São Paulo, Brazil, were evaluated by means of content analysis. Results showed that the actions planed by Santiago’s PHC contributed to 14 SDGs, while in São Paulo, the actions identified contributed to the entire Agenda 2030, although both plans lacked references to the SDGs. In conclusion, the actions planned by the PHC municipal agendas are essential to achieve the SDGs. But this relationship is not adequately reported, which can compromise the allocation of greater resources to this sector. Therefore, greater alignment of local, national, and global action plans and policies, integrated and continuous training for communities and health teams, and greater use and diffusion of technologies already available in a regional and intersectoral approach to municipal health plans are required.O objetivo deste estudo é explorar a importância da Atenção Primária à Saúde (APS) para a consecução dos Objetivos de Desenvolvimento Sustentável (ODS), avaliando as convergências entre duas agendas municipais de APS e a Agenda global 2030. Para tanto, utilizou-se a técnica de análise de conteúdo nas ações de APS previstas nos planos municipais de saúde dos municípios de Santiago do Chile e São Paulo, Brasil. A análise de conteúdo de ambos os planos mostrou que as ações previstas pela APS de Santiago contribuíam com 14 ODS, enquanto em São Paulo foram identificadas ações que contribuíam com a totalidade da Agenda 2030, ainda quando em ambos os planos houve algumas faltas de referência aos ODS. Conclui-se que as ações previstas pela APS em um nível municipal demostram ser essenciais à consecução dos ODS. Porém, esta relação não é informada adequadamente, o que pode comprometer a injeção de maiores incentivos neste setor. Logo, se requer maior alinhamento dos planos e políticas locais, nacionais e globais de ação, uma formação integrada e continuada nas comunidades e para as equipes de saúde, e maior uso e difusão de tecnologias já disponibilizadas em abordagem territorial e intersetorial dos planos municipais de saúde
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