A Method for Creating Structural Models of Text Documents Using Neural Networks.

The article describes modern neural network BERT-based models and considers their application for Natural Language Processing tasks such as question answering and named entity recognition. The article presents a method for solving the problem of automatically creating structural models of text documents. The proposed method is hybrid and is based on jointly utilizing several NLP models. The method builds a structural model of a document by extracting sentences that correspond to various aspects of the document. Information extraction is performed by using the BERT Question Answering model with questions that are prepared separately for each aspect. The answers are filtered via the BERT Named Entity Recognition model and used to generate the contents of each field of the structural model. The article proposes two algorithms for field content generation: Exclusive answer choosing algorithm and Generalizing answer forming algorithm, that are used for short and voluminous fields respectively. The article also describes the software implementation of the proposed method and discusses the results of experiments conducted to evaluate the quality of the method.The article describes modern neural network BERT-based models and considers their application for Natural Language Processing tasks such as question answering and named entity recognition. The article presents a method for solving the problem of automatically creating structural models of text documents. The proposed method is hybrid and is based on jointly utilizing several NLP models. The method builds a structural model of a document by extracting sentences that correspond to various aspects of the document. Information extraction is performed by using the BERT Question Answering model with questions that are prepared separately for each aspect. The answers are filtered via the BERT Named Entity Recognition model and used to generate the contents of each field of the structural model. The article proposes two algorithms for field content generation: Exclusive answer choosing algorithm and Generalizing answer forming algorithm, that are used for short and voluminous fields respectively. The article also describes the software implementation of the proposed method and discusses the results of experiments conducted to evaluate the quality of the method

Supercurrent interference in HgTe Josephson junctions

Wires made of topological insulators (TI) are a promising platform for searching for Majorana bound states. These states can be probed by analyzing the fractional ac Josephson effect in Josephson junctions with the TI wire as a weak link. An axial magnetic field can be used to tune the system from trivial to topologically nontrivial. Here we investigate the oscillations of the supercurrent in such wire Josephson junctions as a function of the axial magnetic field strength and different contact transparencies. Although the current flows on average parallel to the magnetic field we observe h/2e, h/4e- and even h/8e-periodic oscillations of the supercurrent in samples with lower contact transparencies. Corresponding tight-binding transport simulations using a Bogoliubov-de Gennes model Hamiltonian yield the supercurrent through the Josephson junctions, showing in particular the peculiar h/4e-periodic oscillations observed in experiments. A further semiclassical analysis based on Andreev-reflected trajectories connecting the two superconductors allows us to identify the physical origin of these oscillations. They can be related to flux-enclosing paths winding around the TI-nanowire, thereby highlighting the three-dimensional character of the junction geometry compared to common planar junctions

Mathematical modeling of non-steady heat exchange process in cryogenic coil-wound heat exchangers

The paper discusses a dynamic model of coil-wound heat exchanger and its implementation in the MathWorks SimulinkTM computer simulation system. As a simulation object was chosen a coil-wound heat exchanger with wire-finned tubes of a commercial low-capacity air separation unit. The methods for obtaining experimental data has been described, the non-steady heat exchange process has been simulated, and the obtained results have been analyzed

Mathematical modeling of non-steady heat exchange process in cryogenic coil-wound heat exchangers

The paper discusses a dynamic model of coil-wound heat exchanger and its implementation in the MathWorks SimulinkTM computer simulation system. As a simulation object was chosen a coil-wound heat exchanger with wire-finned tubes of a commercial low-capacity air separation unit. The methods for obtaining experimental data has been described, the non-steady heat exchange process has been simulated, and the obtained results have been analyzed

Ballistic geometric resistance resonances in a single surface of a topological insulator

Ballistic motion on nanometer scale of topological surface states has rarely been studied. Here, Maier et al. report pronounced geometric resistance resonances of high-mobility Dirac electrons in strained HgTe, suggesting a ballistic effect in three-dimensional topological insulators

4π -periodic supercurrent tuned by an axial magnetic flux in topological insulator nanowires

Topological insulator (TI) nanowires in proximity to conventional superconductors have been proposed as a tunable platform to realize topological superconductivity and Majorana zero modes. The tuning is done using an axial magnetic flux φ which allows transforming the system from trivial at φ = 0 to topologically nontrivial when half a magnetic flux quantum φ_0/2 threads the cross-section of the wire. Here, we explore the expected topological transition in TI-wire-based Josephson junctions as a function of magnetic flux by probing the 4π-periodic fraction of the supercurrent, which is considered an indicator of topological superconductivity. Our data suggest that this 4π-periodic supercurrent is at lower magnetic field largely of trivial origin but that, at magnetic fields above ∼φ_0/4, topological 4π-periodic supercurrents take over

Resonant Oscillations of Josephson Current in Nb-Bi2Te2.3Se0.7-Nb Junctions

Josephson proximity junctions and devices employing topological insulators are promising candidates for realizing topological superconductivity and topologically protected quantum circuits. Here, the new type of oscillations of the critical Josephson current in the ballistic Nb-Bi2Te2.3Se0.7-Nb junctions subject to the magnetic fields is reported. The oscillations appear below ≈400 mK and have a very unusual sharp-peaked shape. Their ultra-short period ≈1 Oe, by orders of magnitude shorter than the expected periodicity due to fluxoid quantization in the device, corresponds to the extremely low energy scale ≈1 (Formula presented.) eV. It is established that the observed effect is due to the resonant transmission of Andreev quasiparticles via the peculiar energy levels forming near the S-TI interfaces