Absorption of microwave energy by composites based on magnetic colloids
Absorption of microwave energy by composites based on magnetic colloids
S. A. Bozhenko$^1$, S. D. Turkin$^2$, A. R. Zakinyan$^2$, L. M. Kulgina$^2$
The absorption and reflection spectra of composites synthesized on the basis of magnetic liquids with the addition of conductive nonmagnetic particles under the influence of a constant magnetic field have been experimentally studied. The measurements were carried out on the main TEM mode of a coaxial waveguide in the frequency range of 10-18 GHz. To interpret the results obtained, numerical modeling of the system under study was carried out in the approximation of an effective medium using the finite element method.
Show AbstractExclusive neutral pion electroproduction off protons from CLAS12 data at beam energy 6.535 GeV
Exclusive neutral pion electroproduction off protons from CLAS12 data at beam energy 6.535 GeV
V. B. Ryzhkov$^1$, A. N. Pavlova$^1$, A. A. Rusova$^{1,2}$, E. L. Isupov$^2$
The first results on the selection of $ep\to e'p'\pi^0$ events from the CLAS12 detector experimental data in the resonance area for the electron beam energy $E_e = 6.535$ GeV are presented in this report. The topology with two detected photons in the final state is analyzed; selections are introduced to isolate events of the single neutral pion electroproduction reaction; the invariant mass of photon pair distributions in various kinematic bins are obtained for the total energy of final hadrons in the $\gamma_v p$ center of mass system $W$ and the photon virtuality $Q^2$. The reaction yields are calculated. The topology with one detected photon is also considered; additional kinematic selections are introduced for this topology.
Show AbstractSpace-like pion off-shell form factors in the Bethe-Salpeter approach
Space-like pion off-shell form factors in the Bethe-Salpeter approach
S. G. Bondarenko$^{1,2}$, M. K. Slautin$^{1,2}$
In the paper, the off-shell electromagnetic pion form factors in the Bethe-Salpeter formalism are considered. The separable kernel of the first rank quark-antiquark interaction is used to solve the equation analytically.The semi-off-shell pion form factors 𝐹1 and 𝐹2, which are related to each other by the Ward-Takahashi identity, are calculated. The obtained off-shell form factors as well as static properties of the pion are compared with the results of other authors
Show AbstractRare decay D→ωl+l
Rare decay D→ωl+l
V. .. Galkin$^1$, I. .. Sukhanov$^{1,2}$
Rare decays of charmed mesons due to flavour-changing weak neutral currents are forbidden at the tree level in the Standard Model and are additionally suppressed by the Glashow-Iliopoulos-Maiani mechanism. As a result, the role of intermediate resonance contributions increases significantly. Rare decays of $D$ meson into light vector meson $\omega$ are studied in detail within the framework of the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The effects of electroweak physics at short distances and the contributions of intermediate resonances at large distances are taken into account using effective Wilson coefficients. The obtained results are consistent with the existing upper experimental limits.
Show Abstract$B^- \rightarrow \mu^+ \mu^- e^- \bar{\nu}_e$ decay in orthogonal amplitudes method
$B^- \rightarrow \mu^+ \mu^- e^- \bar{\nu}_e$ decay in orthogonal amplitudes method
D. S. Ostapovich
In the present paper partial widths and differential ditributions of $B^- \rightarrow \mu^+ \mu^- e^- \bar{\nu}_{e}$ and $B^- \rightarrow e^+ e^- \mu^- \bar{\nu}_{\mu}$ decays were calculated, utilizing the orthogonal amlitudes method. Virtual photon emission by the light quark (VMD model), virtual photon emission by the heavy quark and bremsstrahlung were accounted for in calculations. The results obtained are in a satisfactory agreement with experimental constraints.
Show AbstractImproving MRI series correspondence using a modified TransMorph neural network
Improving MRI series correspondence using a modified TransMorph neural network
N. A. Nefediev$^1$, N. E. Staroverov$^2$, R. V. Davydov$^3$
Improving the quality of the training sample is an important aspect when training artificial intelligence modules to solve medical problems. In this study, we applied the TransMorph neural network to solve the DIR problem with respect to MRI series. We modified TransMorph using an additional convolutional layer with settings similar to the Sobel filter. The modification made it possible to improve the result of solving the DIR problem relative to the original TransMorph architecture. The results of comparing the original and modified models based on their application to MRI data of the head and MRI of the male pelvis are presented.
Show AbstractDeep-learning detection of human cardiovascular system deterioration from pulse-wave signals
Deep-learning detection of human cardiovascular system deterioration from pulse-wave signals
S. -. Msokar, R. V. Davydov
Cardiovascular diseases (CVD) are among the leading causes of mortality worldwide, making the early detection of pathological changes critically important for timely intervention. This study presents a developed neural network model designed to detect and monitor adverse changes in the human cardiovascular system through the analysis of pulse wave signals. The research utilizes a medical dataset comprising 657 data recordings from 219 patients. The dataset covers an age range of 20–89 years and includes records on disease presence and stage. The data were filtered and processed for feature extraction. After training, the model demonstrated an accuracy of 93% on test data, confirming its potential for integration into wearable devices and remote health monitoring systems.
Show AbstractCalibration and optimal control for inaccurate predictive models
Calibration and optimal control for inaccurate predictive models
E. M. Churakov, P. V. Golubtsov
The problem of managing physical systems is considered. In such systems, there are various parameters: which we can control directly, which we can control indirectly through the first parameters and parameters that act as external disturbances of the system. The values of all variables come to us as sensor measurements, and the sensors, in turn, have measurement errors. In addition to perturbations and errors, there is another fundamental problem: We always know the model of a physical system inaccurately, this may be due to insufficient information or lack of a priori information about the type of model.
Show AbstractUsing Lasso-regression to select significant exogenous features in time series forecasting
Using Lasso-regression to select significant exogenous features in time series forecasting
A. I. Baliuk
It is proposed to make the preliminary processing of multidimensional time series and optimize the selection of exogenous variables using the least squares method with regularization, in order to use the obtained results in the SARIMAX model. The analysis of weather and atmospheric data of the Tver Oblast showed that the selection of significant exogenous features using Lasso-regression allows minimizing the forecast error and preventing model overfitting. The results obtained confirm that the correct choice of exogenous variables improves the quality of the predictive model.
Show AbstractA new technique for controlling scale discreteness in a differential mobile refractometer
A new technique for controlling scale discreteness in a differential mobile refractometer
A. D. Belyaev, V. V. Davydov
The necessity of developing a small-sized mobile refractometer for express control of the state of hydrocarbon media and a new method for determining their composition and concentration of components in case the medium is a mixture of two hydrocarbon media is substantiated. This method will allow for comprehensive control of hydrocarbon media at the sampling site and making an informed decision on their intended use without additional studies in a stationary laboratory. This will save time and resources when solving many problems related to the use of fuel (for example, for mobile objects, etc.). The new method is characterized by the speed of measurements and does not require special sample preparation. The error in measuring the refractive index is ± 0.0002, which is sufficient for reliable express control. The studies of hydrocarbon media and their mixtures confirmed the adequacy of the development and the reliability of determining the composition of the hydrocarbon mixture and the concentration of components.
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