6,929 research outputs found

    Towards a Semantic Gas Source Localization under Uncertainty

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    Towards a Semantic Gas Source Localization under Uncertainty.Communications in Computer and Information Science book series (CCIS, volume 855), doi:10.1007/978-3-319-91479-4_42This work addresses the problem of efficiently and coherently locating a gas source in a domestic environment with a mobile robot, meaning efficiently the coverage of the shortest distance as possible and coherently the consideration of different gas sources explaining the gas presence. The main contribution is the exploitation, for the first time, of semantic relationships between the gases detected and the objects present in the environment to face this challenging issue. Our proposal also takes into account both the uncertainty inherent in the gas classification and object recognition processes. These uncertainties are combined through a probabilistic Bayesian framework to provide a priority-ordered list of (previously observed) objects to check. Moreover the proximity of the different candidates to the current robot location is also considered by a cost function, which output is used for planning the robot inspection path. We have conducted an initial demonstration of the suitability of our gas source localization approach by simulating this task within domestic environments for a variable number of objects, and comparing it with an greedy approach.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Diseño, desarrollo y evaluación de situaciones problemáticas de estadística. El caso de los tests de hipótesis

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    Este libro es el resultado de un trabajo de investigación realizado por un grupo de investigadores de "una empresa docente" que trabajaron en el diseño, desarrollo y evaluación de un conjunto de situaciones problemáticas de estadística de tests de hipótesis. En el libro se presentan una serie de elementos teóricos bajo los cuales se desarrolla un análisis de tipo didáctico que considera tres facetas de análisis. La primera se refiere al contenido, la segunda al aprendizaje y la tercera a la enseñanza. En el análisis de contenido se consideran entre otras, las ideas de conocimiento conceptual y conocimiento procedimental y se propone una estructura concreta para el análisis del contenido de una situación problemática de test de hipótesis. En el análisis de aprendizaje se consideran conceptos tales como error, dificultad y obstáculo y se presenta una caracterización informal del aprendizaje y la comprensión de los estudiantes considerados en el estudio. En el análisis de la enseñanza, se resalta la importancia de los análisis de los textos de enseñanza y se considera la implementación de las calculadoras gráficas en el diseño de las situaciones problemáticas. Hay tres capítulos donde explícitamente se consideran las reflexiones de los investiadores alrededor del proceso de diseño, desarrollo y evaluación de las situacione problemáticas. El primero trata el tema de inferencia acerca de la proporción de una población, el segundo el tema de inferencia acerca de la diferencia de la media de dos poblaciones, y el último considera la inferencia acerca del coeficiente de correlación de Pearson de una población. El lector interesado en el tema de la educación estadística puede encontrar en este libro un valioso instrumento de ayuda para desarrollar su labor docente y para iniciar procesos de investigación en este campo

    Throughput Performance Evaluation of Multiservice Multirate OCDMA in Flexible Networks

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    \u3cp\u3eIn this paper, new analytical formalisms to evaluate the packet throughput of multiservice multirate slotted ALOHA optical code-division multiple-access (OCDMA) networks are proposed. The proposed formalisms can be successfully applied to 1-D and 2-D OCDMA networks with any number of user classes in the system. The bit error rate (BER) and packet correct probability expressions are derived, considering the multiple-access interference as binomially distributed. Packet throughput expressions, on the other hand, are derived considering Poisson, binomial, and Markov chain approaches for the composite packet arrivals distributions, with the latter defined as benchmark. A throughput performance evaluation is carried out for two distinct user code sequences separately, namely, 1-D and 2-D multiweight multilength optical orthogonal code (MWML-OOC). Numerical results show that the Poisson approach underestimates the throughput performance in unacceptable levels and incorrectly predicts the number of successfully received packets for most offered load values even in favorable conditions, such as for the 2-D MWML-OOC OCDMA network with a considerably large number of simultaneous users. On the other hand, the binomial approach proved to be more straightforward, computationally more efficient, and just as accurate as the Markov chain approach.\u3c/p\u3

    Ithlete Heart Rate Variability app: Knowing when to train

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    ‘ithlete Heart Rate Variability’ app has been scientifically designed for monitoring the body heart rate and give information about when to train and when to rest. The process of training is stressing and has an impact on health. This app offers a very quick and healthy biofeedback of how stressed, recovered and ready for training your body is. It can also avoid injuries by giving users information related to optimising the effectiveness of their workout sequence. The app allows users to register their heart rate variability (HRV) and the time gap between the heartbeats when the body is resting, in order to offer users a more precise picture of their overall health and fitness status (figure 1). HRV, the beat-to-beat variation in either heart rate or the duration of the R-R interval, has become an increasing important clinical diagnostic tool. For example, Lombardi and Stein1 review the relationship between HRV and heart rate turbulence, while Huikuri and Stein2 evaluate HRV as a tool for risk assessment in patients recovering from myocardial infarction

    Screening of Indigenous Microorganisms as Potential Biofertilisers for Periurban Horticulture Areas

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    In Buenos Aires periurban area, horticultural practices are one of the most important activities. Pesticides and fertilisers are used without any control to cover the farmers’ needs, obtaining high crop yields at short terms and modifying soil ecosystem in the long term. The aim of this work was to isolate indigenous strains from periurban horticultural units with pesticide degrading capacity and to evaluate their plant growth-promoting properties in order to design biofertilisers to be applied in the restoration of these exploited soils. After the screening, eight strains were isolated and identified. They showed not only the capacity to produce indole-3- acetic acid, to fix nitrogen, to secrete siderophores and to solubilise calcium phosphate but also tolerated the mixture of pesticides usually used for horticultural practices. By their behaviour in mixed cultures and plant growth-promoting properties, these autochthonous isolates represent a promising alternative as biofertilisers according to soil type and activity
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