1. Precision magnetometry exploiting excited state quantum phase transitionsQian Wang, Ugo Marzolino, 2024, izvirni znanstveni članek Opis: Critical behaviour in phase transitions is a resource for enhanced precision metrology. The reason is that the function, known as Fisher information, is superextensive at critical points, and, at the same time, quantifies performances of metrological protocols. Therefore, preparing metrological probes at phase transitions provides enhanced precision in measuring the transition control parameter. We focus on the Lipkin-Meshkov-Glick model that exhibits excited state quantum phase transitions at different magnetic fields. Resting on the model spectral properties, we show broad peaks of the Fisher information, and propose efficient schemes for precision magnetometry. The Lipkin-Meshkov-Glick model was first introduced for superconductivity and for nuclear systems, and recently realised in several condensed matter platforms. The above metrological schemes can be also exploited to measure microscopic properties of systems able to simulate the LipkinMeshkov-Glick model.
Ključne besede: magnetometry, quantum phase transitions, precision, measurements
Objavljeno v DKUM: 22.08.2024; Ogledov: 62; Prenosov: 10
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2. Vine canopy reconstruction and assessment with terrestrial lidar and aerial imagingIgor Petrović, Matej Sečnik, Marko Hočevar, Peter Berk, 2022, izvirni znanstveni članek Opis: For successful dosing of plant protection products, the characteristics of the vine canopies should be known, based on which the spray amount should be dosed. In the field experiment, we compared two optical experimental methods, terrestrial lidar and aerial photogrammetry, with manual defoliation of some selected vines. Like those of other authors, our results show that both terrestrial lidar and aerial photogrammetry were able to represent the canopy well with correlation coefficients around 0.9 between the measured variables and the number of leaves. We found that in the case of aerial photogrammetry, significantly more points were found in the point cloud, but this depended on the choice of the ground sampling distance. Our results show that in the case of aerial UAS photogrammetry, subdividing the vine canopy segments to 5 × 5 cm gives the best representation of the volume of vine canopies.
Ključne besede: precision agriculture, remote sensing, 3D point clouds, vineyard, canopy reconstruction, terrestrial lidar, aerial photogrammetry, manual defoliation
Objavljeno v DKUM: 15.07.2024; Ogledov: 123; Prenosov: 8
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3. Possibilities and concerns of implementing precision agriculture technologies on small farms in SloveniaJurij Rakun, Erik Rihter, Damijan Kelc, Denis Stajnko, Peter Vindiš, Peter Berk, Peter Polič, Miran Lakota, 2022, izvirni znanstveni članek Opis: Precision agriculture (PA) through the use and utilization of innovative technologies is a concept in agricultural management that enables long-term efficiency gains, control of unforeseen changes, and a reduction of negative impacts on the environment. However, there are even more reasons and benefits to using precision agriculture technologies (PATs) on farms, but the actual use on small farms is often questionable. The main objective of this research was to evaluate and analyze the current state of PA and its potential on a set of small farms. In addition, a comparison was made between small farms located in less favored areas (LFAs) and more favored areas (MFAs) to find if specific characteristics of the surrounding environment affect the (non-) implementation of these technologies by farm owners, with respect to the given regional possibilities. The result shows that 57.5% of respondents on these farms have never implemented PATs before and 20% are beginners in their respective fields. It was found that there were no statistically significant differences in the integration between fewer LFAs and MFAs technologies and their use in this study. The majority of respondents believe that the main changes need to occur on the level of politics. The results show that the level of cost or initial investment is the main reason and the main obstacle in the implementation of PATs on the surveyed farms.
Ključne besede: precision agriculture, small farm, technological innovations, implementation, situation overview, survey, ICT
Objavljeno v DKUM: 02.07.2024; Ogledov: 161; Prenosov: 12
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4. Sensor fusion-based approach for the field robot localization on Rovitis 4.0 vineyard robotJurij Rakun, Matteo Pantano, Peter Lepej, Miran Lakota, 2022, izvirni znanstveni članek Opis: This study proposed an approach for robot localization using data from multiple low-cost sensors with two goals in mind, to produce accurate localization data and to keep the computation as simple as possible. The approach used data from wheel odometry, inertial-motion data from the Inertial Motion Unit (IMU), and a location fix from a Real-Time Kinematics Global Positioning System (RTK GPS). Each of the sensors is prone to errors in some situations, resulting in inaccurate localization. The odometry is affected by errors caused by slipping when turning the robot or putting it on slippery ground. The IMU produces drifts due to vibrations, and RTK GPS does not return to an accurate fix in (semi-) occluded areas. None of these sensors is accurate enough to produce a precise reading for a sound localization of the robot in an outdoor environment. To solve this challenge, sensor fusion was implemented on the robot to prevent possible localization errors. It worked by selecting the most accurate readings in a given moment to produce a precise pose estimation. To evaluate the approach, two different tests were performed, one with robot localization from the robot operating system (ROS) repository and the other with the presented Field Robot Localization. The first did not perform well, while the second did and was evaluated by comparing the location and orientation estimate with ground truth, captured by a hovering drone above the testing ground, which revealed an average error of 0.005 m±0.220 m in estimating the position, and 0.6°±3.5° when estimating orientation. The tests proved that the developed field robot localization is accurate and robust enough to be used on a ROVITIS 4.0 vineyard robot.
Ključne besede: localization, odometry, IMU, RTK GPS, vineyard, robot, sensors fusion, ROS, precision farming
Objavljeno v DKUM: 02.07.2024; Ogledov: 123; Prenosov: 13
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5. Measurement of the branching fraction and ▫$CP$▫ asymmetry for ▫$B \to \bar{D}^0 \pi$▫ decaysT. Bloomfield, Jyoti Prakash Biswal, Marko Bračko, Samo Korpar, Peter Križan, Rok Pestotnik, Tomaž Podobnik, Marko Starič, Luka Šantelj, 2022, izvirni znanstveni članek Opis: We measure the branching fractions and CP asymmetries for the decays B⁰ → D¯ 0π⁰ and B⁺ → D¯ 0π⁺, using a data sample of 772 × 10⁶ BB¯ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB e⁺e− collider. The branching fractions obtained and direct CP asym-metries are B(B⁰ → D¯ 0π⁰)=[2.70 0.06(stat) 0.10(syst)]×10−⁴, B(B⁺ → D¯ 0π⁺)=[4.53 0.02(stat) 0.15(syst)]×10−³, ACP(B⁰ → D¯ 0π⁰)= [+0.42 2.05(stat) 1.22(syst)]%, and ACP(B⁺ → D¯ 0π⁺) = [+0.19 0.36(stat) 0.57(syst)]%. The measurements of B are the most precise to date and are in good agreement with previous results, as is the measurement of ACP(B⁺ → D¯ 0π⁺). The measurement of ACP for B⁰ → D¯ 0π⁰ is the first for this mode, and the value is consistent with Standard Model expectations.
Ključne besede: branching fraction, hadronic decays, particle decays, mesons, CP violation, precision measurements
Objavljeno v DKUM: 17.08.2023; Ogledov: 364; Prenosov: 39
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6. High resolution switching mode inductance-to-frequency converter with temperature compensationVojko Matko, Miro Milanovič, 2014, izvirni znanstveni članek Opis: This article proposes a novel method for the temperature-compensated inductance-to-frequency converter with a single quartz crystal oscillating in the switching oscillating circuit to achieve better temperature stability of the converter. The novelty of this method lies in the switching-mode converter, the use of additionally connected impedances in parallel to the shunt capacitances of the quartz crystal, and two inductances in series to the quartz crystal. This brings a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 10 and 40 °C. The oscillator switching method and the switching impedances connected to the quartz crystal do not only compensate for the crystalʼs natural temperature characteristics but also any other influences on the crystal such as ageing as well as from other oscillating circuit elements. In addition, the method also improves frequency sensitivity in inductance measurements. The experimental results show that through high temperature compensation improvement of the quartz crystal characteristics, this switching method theoretically enables a 2 pH resolution. It converts inductance to frequency in the range of 85-100 nH to 2-560 kHz.
Ključne besede: inductance-to-frequency, switching methods, dynamic temperature compensation of circuit elements, precision metrology
Objavljeno v DKUM: 22.06.2017; Ogledov: 1075; Prenosov: 347
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