160 research outputs found

    STATE AND PERSPECTIVES IN COMPETITIVENESS OF ONE FARM TYPE IN SERBIA

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    In the paper is analyzed competitiveness of Serbian family dairy farms in lowland region in 2007, with some aspects of possible perspectives. Globalization process, expected EU integrations and set of free trade agreements will expose Serbian farms in close future to higher level of competition. Identified structural changes, refers on dairy farms concentration and specialization in lowland region in recent years. Estimated model of cost function revealed that family farms with bigger herd size have lower average costs of milk production. Economic efficiency, measured in terms of cost efficiency, shows that larger dairy farms are more efficient. But, not all smaller farms are inefficient. Due to good management some smaller farms are competitive on national market. Milk price volatility in period 2007 to 2009 hurts all farms, but the most farms with higher average costs, which are usually inefficient dairy farms.Competitiveness, Dairy enterprise, Dairy farm, Milk production, Serbia, Agribusiness, Livestock Production/Industries,

    Obstacle-aware Adaptive Informative Path Planning for UAV-based Target Search

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    Target search with unmanned aerial vehicles (UAVs) is relevant problem to many scenarios, e.g., search and rescue (SaR). However, a key challenge is planning paths for maximal search efficiency given flight time constraints. To address this, we propose the Obstacle-aware Adaptive Informative Path Planning (OA-IPP) algorithm for target search in cluttered environments using UAVs. Our approach leverages a layered planning strategy using a Gaussian Process (GP)-based model of target occupancy to generate informative paths in continuous 3D space. Within this framework, we introduce an adaptive replanning scheme which allows us to trade off between information gain, field coverage, sensor performance, and collision avoidance for efficient target detection. Extensive simulations show that our OA-IPP method performs better than state-of-the-art planners, and we demonstrate its application in a realistic urban SaR scenario.Comment: Paper accepted for International Conference on Robotics and Automation (ICRA-2019) to be held at Montreal, Canad

    Online Informative Path Planning for Active Classification on UAVs

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    We propose an informative path planning (IPP) algorithm for active classification using an unmanned aerial vehicle (UAV), focusing on weed detection in precision agriculture. We model the presence of weeds on farmland using an occupancy grid and generate plans according to information-theoretic objectives, enabling the UAV to gather data efficiently. We use a combination of global viewpoint selection and evolutionary optimization to refine the UAV's trajectory in continuous space while satisfying dynamic constraints. We validate our approach in simulation by comparing against standard "lawnmower" coverage, and study the effects of varying objectives and optimization strategies. We plan to evaluate our algorithm on a real platform in the immediate future.Comment: 7 pages, 4 figures, submission to International Symposium on Experimental Robotics 201

    Informative Path Planning for Active Field Mapping under Localization Uncertainty

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    Information gathering algorithms play a key role in unlocking the potential of robots for efficient data collection in a wide range of applications. However, most existing strategies neglect the fundamental problem of the robot pose uncertainty, which is an implicit requirement for creating robust, high-quality maps. To address this issue, we introduce an informative planning framework for active mapping that explicitly accounts for the pose uncertainty in both the mapping and planning tasks. Our strategy exploits a Gaussian Process (GP) model to capture a target environmental field given the uncertainty on its inputs. For planning, we formulate a new utility function that couples the localization and field mapping objectives in GP-based mapping scenarios in a principled way, without relying on any manually tuned parameters. Extensive simulations show that our approach outperforms existing strategies, with reductions in mean pose uncertainty and map error. We also present a proof of concept in an indoor temperature mapping scenario.Comment: 8 pages, 7 figures, submission (revised) to Robotics & Automation Letters (and IEEE International Conference on Robotics and Automation

    A New Approach to Evaluation of University Teaching Considering Heterogeneity of Students’ Preferences

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    AbstractStudents’ evaluations of teaching are increasingly used by universities to evaluate teaching performance. However, these evaluations are controversial mainly due to fact that students value various aspects of excellent teaching differently. Therefore, in this paper we propose a new approach to student evaluation of university teaching based on data from conjoint analysis. Conjoint analysis is a multivariate technique used to analyze the structure of individuals’ preference. In particular, our approach accounts for different importance students attach to various aspects of teaching. Moreover, it accounts explicitly for heterogeneity arising from student preferences, and incorporates it to form comprehensive teaching evaluation score. We have conducted survey and confirmed applicability and efficiency of the proposed approach

    Effects of n-3 Fatty Acids Supplementation on Plasma Phospholipids Fatty Acid Composition in Patients with Obstructive Jaundice- a Pilot Study

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    Nutritional and immunological status of patients with obstructive jaundice is usually severely altered, with high mortality rates. The n-3 polyunsaturate fatty acids (PUFA), particularly eicosapentaenoic acid (EPA, 20:5 n-3), posess potent immunomodulatory activities. Thus, our aim was to compare the plasma phospholipid fatty acid (FA) composition of these patients with healthy subjects, as well as before and after 7 days preoperative supplementation with high doses of EPA (0.9 g per day) and docosahexaenoic acid (DHA, 22:6 n-3, 0.6 g per day). We found impaired FA status in obstructive jaundice patients, especially EPA, DHA and PUFA, but significantly increased content of total n-3 FA, 22:5 n-3 FA and particularly EPA, which increased more than 3 fold, after 7 days supplementation. In addition, the n6/n3 ratio significantly decreased from 14.24 to 10.24, demonstrating severely improved plasma phospholipid profile in these patients after the intervention

    Specifics of marketing in overcoming discrepancies on the market of agricultural products

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