27 research outputs found

    Unmanned Ground Vehicles in Precision Farming Services: An Integrated Emulation Modelling Approach

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    Autonomous systems are a promising alternative for safely executing precision farming activities in a 24/7 perspective. In this context Unmanned Ground Vehicles (UGVs) are used in custom agricultural fields, with sophisticated sensors and data fusion techniques for real-time mapping and navigation. The aim of this study is to present a simulation software tool for providing effective and efficient farming activities in orchard fields and demonstrating the applicability of simulation in routing algorithms, hence increasing productivity, while dynamically addressing operational and tactical level uncertainties. The three dimensional virtual world includes the field layout and the static objects (orchard trees, obstacles, physical boundaries) and is constructed in the open source Gazebo simulation software while the Robot Operating System (ROS) and the implemented algorithms are tested using a custom vehicle. As a result a routing algorithm is executed and enables the UGV to pass through all the orchard trees while dynamically avoiding static and dynamic obstacles. Unlike existing sophisticated tools, the developed mechanism could accommodate an extensive variety of agricultural activities and could be transparently transferred from the simulation environment to real world ROS compatible UGVs providing user-friendly and highly customizable navigation

    Scheduling and control of unmanned ground vehicles for precision farming: A real-time navigation tool

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    Copyright © 2017 for this paper by its author Autonomous systems are a promising alternative for effectively executing agricultural field management strategies. Unmanned Ground Vehicles perform farming activities on custom agricultural fields, using real-time navigation. The aim of this study is to provide a software tool for optimizing accuracy and efficiency in precision farming activities, hence leading to improved farming output, while dynamically addressing operational and tactical level uncertainties. This paper contributes to the operations research field by allowing the application of simulated results direct to the guidance of a physical vehicle. Unlike existing sophisticated tools, the developed navigation mechanism is user-friendly and highly customizable at outdoor navigation

    The circadian phase of antenatal glucocorticoid treatment affects the risk of behavioral disorders

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    During pregnancy, maternal endocrine signals drive fetal development and program the offspring's physiology. A disruption of maternal glucocorticoid (GC) homeostasis increases the child's risk of developing psychiatric disorders later in life. We here show in mice, that the time of day of antenatal GC exposure predicts the behavioral phenotype of the adult offspring. Offspring of mothers receiving GCs out-of-phase compared to their endogenous circadian GC rhythm show elevated anxiety, impaired stress coping, and dysfunctional stress-axis regulation. The fetal circadian clock determines the vulnerability of the stress axis to GC treatment by controlling GC receptor (GR) availability in the hypothalamus. Similarly, a retrospective observational study indicates poorer stress compensatory capacity in 5-year old preterm infants whose mothers received antenatal GCs towards the evening. Our findings offer insights into the circadian physiology of feto-maternal crosstalk and assign a role to the fetal clock as a temporal gatekeeper of GC sensitivity
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