Boxing Punch Detection with Single Static Camera.

Computer vision in sports analytics is gaining in popularity. Monitoring players' performance using cameras is more flexible and does not interfere with player equipment compared to systems using sensors. This provides a wide set of opportunities for computer vision systems that help coaches, reporters, and audiences. This paper provides an introduction to the problem of measuring boxers' performance, with a comprehensive survey of approaches in current science. The main goal of the paper is to provide a system to automatically detect punches in Olympic boxing using a single static camera. The authors use Euclidean distance to measure the distance between boxers and convolutional neural networks to classify footage frames. In order to improve classification performance, we provide and test three approaches to manipulating the images prior to fitting the classifier. The proposed solution achieves 95% balanced accuracy, 49% F1 score for frames with punches, and 97% for frames without punches. Finally, we present a working system for analyses of a boxing scene that marks boxers and labelled frames with detected clashes and punches.

Triticale field phenotyping using RGB camera for ear counting and yield estimation.

Triticale (X Triticosecale Wittmack), a wheat-rye small grain crop hybrid, combines wheat and rye attributes in one hexaploid genome. It is characterized by high adaptability to adverse environmental conditions: drought, soil acidity, salinity and heavy metal ions, poorer soil quality, and waterlogging. So that its cultivation is prospective in a changing climate. Here, we describe RGB on-ground phenotyping of field-grown eighteen triticale market-available cultivars, made in naturally changing light conditions, in two consecutive winter cereals growing seasons: 2018-2019 and 2019-2020. The number of ears was counted on top-down images with an accuracy of 95% and mean average precision (mAP) of 0.71 using advanced object detection algorithm YOLOv4, with ensemble modeling of field imaging captured in two different illumination conditions. A correlation between the number of ears and yield was achieved at the statistical importance of 0.16 for data from 2019. Results are discussed from the perspective of modern breeding and phenotyping bottleneck.

Sub-gap Fano resonances in a topological superconducting wire with on-site Coulomb interactions.

We consider theoretically a 1D-semiconducting wire with strong Rashba interaction in proximity withs-wave superconductor, driven into topological phase by external magnetic field. Additionally, we take into account on-site Coulomb interactions inside the wire. The system is modelled by a tight binding Hamiltonian with Rashba hopping term and induceds-wave superconductivity. Calculations are performed utilizing recursive Green's function method, and Coulomb interactions are treated selfconsistently within Hubbard I approximation. For the Hubbard levels residing withinp-wave superconducting gap, particle-hole symmetric four-resonance structure develops in the density of states, apart from Majorana resonance. One pair of particle-hole symmetric resonances is created by the discrete II-Hubbard levels of the particular site, and the second pair of Hubbard sub-bands originates from recursive summation over the sites of the wire. Quantum interference between both types of pairs of states creates in-gap charge-conjugated Fano resonances with opposite asymmetry factors. We demonstrate that when quantum interference is dominated by two-particle tunneling, the Majorana resonance is strongly diminished, while it is not altered when single-particle tunneling dominates in interference process. We also discuss some consequences for experimental distinction of true Majorana states, and show that on-site Coulomb interactions support the appearance of topological phase.

Properties of the Majorana-state tunneling Josephson junction mediated by an interacting quantum dot.

We consider a model of a Josephson junction of two topological superconducting wires mediated by an interacting quantum dot. An additional normal electrode coupled to the dot from the top allows to probe its density of states. The Majorana states adjacent to the dot hybridize across the junction and from a bound state in the dot. The dot is subjected to the effective magnetic field arising from the superposition of the fields driving each wire into topological states, which, dependent on the angle between the fields, introduces variable Zeeman splitting of the dot active level. We show that electron interactions in the dot diminish the characteristic for Majoranas zero bias peak arising in the transverse conductance through the dot and introduce an overall asymmetry of the conductance. They also renormalize the hybridization between the end-state Majoranas in shorter wires. The Majorana spin polarization is determined by the effective magnetic field in the dot. Phase-biased Josephson current exhibits spin polarization in thermal equilibrium, which possesses characteristic [Formula: see text] periodicity, and its sign can be switched when an unpaired Majorana state is present in the junction. We also observe spin-dependent Majorana state 'leaking', which can be controlled by the position of the dot level in energy scale.

Transport properties of a quantum dot-mediated fractional Josephson junction.

We consider a model of a Josephson junction mediated by a quantum dot. An additional normal electrode coupled to the dot allows its density of states to be probed. The junction is made out of two topological superconducting wires with Majorana end states. The two of them, on each side and in the proximity of the junction, convert into a Dirac fermion inside the dot. It is shown that both the density of states of the dot and the phase-biased current through the junction can exhibit [Formula: see text] periodicity in the superconducting phase difference, when the particle-hole symmetry of the junction is broken. It is realized by detuning of the dot level from the Fermi level by the gate voltage. The width of zero-bias peak in differential conductance, produced by an unpaired Majorana state, also possesses [Formula: see text] periodicity under this condition.

Spin selective pseudogap Kondo effect in a double quantum dot interferometer with Rashba interaction.

A system composed of two quantum dots, i.e. a strongly interacting Kondo dot and a noninteracting one, placed in the arms of the Aharonov-Bohm ring, is investigated theoretically. The ring is coupled to normal leads. This configuration is mapped on the system of a correlated impurity embedded in a host with energy and flux dependent density of states. Additionally, the presence of the Rashba field allows a spin selective opening of the pseudogap in the density of states of the host, when the level of the noninteracting dot is tuned to the Fermi energy. This selectively diminishes electron correlations in the Kondo dot and creates resultant spin polarization at the Fermi level. It is shown that this polarization arises in the absence of any exchange field. Interestingly, this Rashba-correlation-induced spin polarization reaches its maximum for the position of the Kondo dot level corresponding to the Kondo temperature of the Anderson impurity in the host with constant density of states.

Interplay between quantum interference and electron interactions in a Rashba system.

We investigate theoretically a nanoscopic device in which quantum interference of electron waves takes place in the presence of their mutual Coulomb interaction. The device consists of interacting quantum dots coupled to spin-polarized leads via quantum point contacts with Rashba interaction. The Rashba spin-flip-assisted inter-subband mixing in quantum point contacts induces quantum interference between the tunneling waves, which interact by Coulomb repulsion inside the dot. The spin-dependent Fano resonances, which appear in the conductance through the device, are significantly modified by Coulomb interactions. Their width and shape depend on the quantum dot spin-up and spin-down occupancies, controlled by electron interactions. On the other hand, correlators calculated for the quantum dot spin sub-levels are not influenced by quantum interference between them and depend rather on the degree of localization of these levels.

Fano versus Kondo resonances in a multilevel "semiopen" quantum dot.

Linear conductance across a large quantum dot via a single level epsilon(0) with large hybridization to the contacts is strongly sensitive to quasibound states localized in the dot and weakly coupled to epsilon(0). The conductance oscillates with the gate voltage due to interference of the Fano type. At low temperature and Coulomb blockade, Kondo correlations damp the oscillations on an extended range of gate voltage values, by freezing the occupancy of the epsilon(0) level itself. As a consequence, the antiresonances of Fano origin are washed out. The results are in good correspondence with experimental data for a large quantum dot in the semiopen regime.