737 research outputs found
Individual and peer comparison open learner model visualisations to identify what to work on next
Open learner models (OLM) can support self-regulated learning, collaborative interaction, and navigation in adaptive educational systems. Previous research has found that learners have a range of preferences for learner model visualisation. However, research has focused mainly on visualisations that are available in a single system, meaning that not all visualisations have been compared to each other. We present a study using screen shots of OLM visualisations for individuals and for comparing one's own learner model to the models of other individuals or the group, to define visualisations that students would be able to use to identify their next steps, across a wider range of options
Reinforcement Learning to Control Lift Coefficient Using Distributed Sensors on a Wind Tunnel Model
Arrays of sensors distributed on the wing of fixed-wing vehicles can provide information not directly available to conventional sensor suites. These arrays of sensors have the potential to improve flight control and overall flight performance of small fixed-wing uninhabited aerial vehicles (UAVs). This work investigated the feasibility of estimating and controlling aerodynamic coefficients using the experimental readings of distributed pressure and strain sensors across a wing. The study was performed on a one degree-of-freedom model about pitch of a fixed-wing platform instrumented with the distributed sensing system. A series of reinforcement learning (RL) agents were trained in simulation for lift coefficient control, then validated in wind tunnel experiments. The performance of RL-based controllers with different sets of inputs in the observation space were compared with each other and with that of a manually tuned PID controller. Results showed that hybrid RL agents that used both distributed sensing data and conventional sensors performed best across the different tests.</p
Unmanned aerial vehicle control costs mirror bird behaviour when soaring close to buildings
Small unmanned aerial vehicles (SUAVs) are suitable for many low-altitude operations in urban environments due to their manoeuvrability; however, their flight performance is limited by their on-board energy storage and their ability to cope with high levels of turbulence. Birds exploit the atmospheric boundary layer in urban environments, reducing their energetic flight costs by using orographic lift generated by buildings. This behaviour could be mimicked by fixed-wing SUAVs to overcome their energy limitations if flight control can be maintained in the increased turbulence present in these conditions. Here, the control effort required and energetic benefits for a SUAV flying parallel to buildings whilst using orographic lift was investigated. A flight dynamics and control model was developed for a powered SUAV and used to simulate flight control performance in different turbulent wind conditions. It was found that the control effort required decreased with increasing altitude and that the mean throttle required increased with greater radial distance to the buildings. However, the simulations showed that flying close to the buildings in strong wind speeds increased the risk of collision. Overall, the results suggested that a strategy of flying directly over the front corner of the buildings appears to minimise the control effort required for a given level of orographic lift, a strategy that mirrors the behaviour of gulls in high wind speeds
A CADEIA PRODUTIVA DE CAQUI NO MUNICÃPIO DE ANTÔNIO CARLOS SOB A ÓTICA DA ECONOMIA DOS CUSTOS DE TRANSAÇÃO
This work discusses the importance of the kaki productive chain in the Antônio Carlos district and its growing potentialities, analysed from the perspective of Transaction Costs Economics. The objective is to verify how the transactions between the kaki producers from the Antônio Carlos district and the downstream and upstream agents of the productive chain occur, as well as to study the governance structure in this chain. The data were obtained from semi-structured interviews carried out with seven producers, who were chosen according to criteria such as accessibility and representativity of the district’s production. It was verified that the contracts made between the producers and the downstream industry are classic and the form of governance is the market. In transactions between the producers and the distributors, the contracts are relational and governance is bilateral. It was observed that an effective association is necessary to provide better conditions for the purchase of inputs and the distribution of the product.transaction costs, kaki, specificity, Agribusiness, Agricultural Finance, Industrial Organization,
Análise do crescimento do cultivo intercalar de milho com Crotalaria juncea cultivada em diferentes intervalos de semeadura.
Espiritualidade e as redes sociais: uma análise sobre a presença de Sri Prem baba na internet
O presente artigo tem o objetivo de fazer uma conexão entre as redes sociais e a espiritualidade. Para isso foi utilizado o método de pesquisa teórica de autores relacionados ao marketing digital, foi aplicada pesquisa de campo com usuários da internet e foram feitas entrevistas com Sri Prem Baba, com o coordenador da Sociedade Ginástica Internacional e com publicador do Canal MOVA. Com isso, pretendeu-se demonstrar que as redes sociais e a internet de modo geral atuam como facilitadoras da religiosidade na vida das pessoas e contribuem para que grupos de interesses em comum se unam em prol da espiritualização e do autoconhecimento, assim como são ferramentas essenciais para o bom andamento da missão recebida e o trabalho realizado por Prem Baba
Realidade virtual na reabilitação física de pacientes com doença de Parkinson
Abstract: The Virtual Reality (VR) can be a therapeutic tool used in neurorehabilitation field. It is considered a ludic activity that provides visual and auditory feedbacks, facilitating the patients’ adherence to treatment. AIMS: To perform literature review about influences of VR in rehabilitation of patients with Parkinson’s disease. METHODS: Data banks were used from the following virtual libraries: Medline, PEDro, Lilacs, Scielo and PubMed using the following keywords: Parkinson’s disease and Virtual Reality; Parkinson’s disease and Wii as well as analogous keywords in Spanish and Portuguese to obtain the scientific papers. PEDro scale was used to analyze the methodological quality of the papers. RESULTS: From fifty papers obtained after inclusion and exclusion criteria were retained 16 papers to analyses. According to PEDro scale most of the papers had low score. The results suggest that VR shows positive aspects in velocity and movement time, balance, gait, postural control and functionality of upper extremities. The ludic activity provided by VR and the contribution of visual and auditory feedbacks of this intervention can be the great potential of this new tool. CONCLUSION: The VR is useful to make potent: motor control, functionality, cognitive capacity and balance, but still need more scientific studies with methodological qualities to confirm the results of the VR in Parkinson’s disease.Introdução: A realidade virtual (RV) pode ser uma ferramenta terapêutica utilizada no campo da neurorreabilitação. É considerada uma atividade lúdica que fornece feedback visual e auditivo, facilitando a adesão dos pacientes ao tratamento. Objetivo: Realizar uma revisão de literatura a respeito da influência da RV na reabilitação de pacientes com doença de Parkinson. Método: Utilizamos como base de dados os sistemas virtuais das bibliotecas Medline, PEDro, Lilacs, Scielo e Pubmed, a partir dos seguintes descritores: Doença de Parkinson e Realidade Virtual; Doença de Parkinson e Wii e seus equivalentes em espanhol e inglês para obtenção dos artigos. Foi utilizada a escala PEDro para fins de pontuação metodológica dos artigos analisados. Resultados: A partir de 50 artigos obtidos após a aplicação dos critérios de inclusão e exclusão, foram obtidos 16 artigos para análise. De acordo com a escala PEDro a maioria dos artigos teve baixa pontuação. Os resultados sugerem que a RV apresenta resultados positivos nas variáveis velocidade e tempo de movimento, equilíbrio, marcha, controle postural e funcionalidade de membros superiores. A atividade lúdica oferecida pela RV e a contribuição dos feedbacks visual e auditivo oferecido por este tipo de intervenção podem ser o grande potencial desta nova ferramenta. Conclusão: A RV é útil na potencialização do controle motor, na funcionalidade, na capacidade cognitiva e no equilíbrio, mas ainda precisa de estudos com melhor qualidade metodológica para confirmação dos resultados da RV na doença de Parkinson
Infection process of Phakopsora gossypii in cotton leaves
Tropical rust caused by the biotrophic fungus Phakopsora gossypii is an emerging disease in cotton that has caused significant yield losses of crop/cotton cultivated in Brazil. Considering the current importance of tropical rust and the need to obtain additional basic information about its causal agent to better control this disease, the present study aimed to determine the infection process of P. gossypii in cotton leaves using scanning electron microscopy (SEM). Thirty-day-old plants were inoculated with a suspension of P. gossypii uredospores, and leaf fragments were collected 42 h after inoculation (hai) as well as 20, 25 and 35 days after inoculation (dai) for SEM observations. By 42 hai, the uredospores of P. gossypii had germinated and produced a germ tube and an appressorium that may directly penetrate the leaf cuticle. At 20 dai, closed uredia containing uredospores were observed on the abaxial leaf surface. At 25 dai, the uredia started to open and became fully open by 35 dai and contained many uredospores. By 25 dai, fungal hyphae were growing abundantly in the mesophyll next to the uredia that formed in the leaf fragments with total or partial removal of the epidermis. The results of the present study provide novel information regarding the infection process of P. gossypii in cotton leaves, which might be useful for the development of new and more effective strategies for tropical rust control
Desempenho agronômico de cultivares de feijão-de-vagem de porte determinado em consórcio com milho em sistema orgânico.
La garantía de la defensa eficaz en el marco del Código Procesal Penal Peruano
La investigación tiene como problema general la siguiente interrogante
¿Cómo influye la Garantía de Defensa Eficaz en el decurso ordinario del Proceso
Penal Peruano?, cuyo objetivo es “Analizar cómo influye la Garantía de Defensa
Eficaz en el decurso ordinario del Proceso Penal Peruano”, y como supuesto “La
Garantía de la Defensa Eficaz influye significativamente en el decurso ordinario
del Proceso Penal Peruano”; habiéndose utilizado como metodología general:
inductivo – deductivo y el analítico – sintético.
La conclusión a la que se arribó “Se determinó que la Garantía de la
Defensa Eficaz, si influye en el decurso ordinario del Proceso Penal, ya que
contiene sub-garantías que asumen un papel fundamental e imprescindible para
la validez y legitimación del proceso penal; por ende, su ausencia deviene en la
nulidad de este, y con ello corregir las deficiencias de la protección de principios
procesales mínimos”
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