Illia Fedorin

National Technical University of Ukraine Kyiv Polytechnic Institute · Department of Biomedical Cybernetics

Recent studies have centered on the potential for effectively controlling the topology state of iso-frequency surfaces in artificial photonic structures using external fields. This paper delves into the topological transitions and singularity states of the isofrequency surface of a highly anisotropic superlattice. This superlattice is composed of a...

The importance of accurate and continuous heart rate monitoring during workout cannot be overestimated. Supporting heart rate in the desired range, you strengthen the heart muscle and the overall fitness level. Therefore, the precise heart rate measurements are important at each stage: before workout, during exercises and after completion. One of t...

Mobile and wearable electronics is one of the rapidly developing areas of high technologies, which regularly appear new devices that offer new features for monitoring our health, level of physical exertion and everyday activity. From the point of view of medicine and sports, usually wearable devices are used to solve one of two tasks: round-the-clo...

Реферат – Сон - це складний психофізіологічний стан, який безпосередньо визначає психічну і біологічну активність людини. Важливість сну обумовлена в першу чергу його необхідністю для організму. Сон – унікальний механізм відновлення та адаптації до умов життя. Одна безсонна ніч знижує стійкість імунітету до інфекційних захворювань і швидкість реакц...

Recently, mobile and wearable devices have become an increasingly integral part of our lives. They provide a possibility of detailed health monitoring using noninvasive and user-friendly techniques. However, lack of continuous monitoring, the need of specific sensors, and the limitations in memory and power consumption are only some of the potentia...

A sleep inertia after waking up strongly affects the overall mental recovery after sleep. The sleep inertia depends not as much on overall sleep quality but also on the sleep stage in the waking up moment. The fix-time alarming system results in waking up at random sleep stage, which results in frequent sleep inertia. The widely used flow-time alar...

This paper provides a novel best in the domain automatic classifier of sleep stages based on wrist photoplethysmography and 3D-accelerometer data obtained from smartwatches. The sleep is classified into rapid-eye-movement (REM), Light, Deep, or Wake stages. State of the art classifiers based on wearable sensors suffer from motion artifacts and apne...

In the current paper the properties of surface plasmon polaritons as well as hybrid polarized surface electromagnetic waves at the plane interface of a porous semiconductor nanomaterial and a hypercrystal are studied theoretically and numerically. The nanomaterial, as well as the hypercrystal, is made of n-type doped indium antimonide (n-InSb) semi...

The dispersion properties of different types of surface electromagnetic waves which are supported by the interface of two nanocomposite materials with inclusions of different shape are studied theoretically and numerically. Both nanocomposites are made of doped n-type semiconductor inclusions which are evenly distributed in a transparent dielectric...

In this paper iso-frequency surfaces of a ferrite-semiconductor superlattice under an action of an external magnetic field are studied. The structure is considered in the subwavelength regime, when it is possible to introduce effective components of permittivity and permeability tensors. It has been shown that due to the peculiarities of the struct...

The properties of surface polaritons as well as Dyakonov surface waves at the plane interface between a nanocomposite made of semiconductor spherical inclusions distributed in a transparent matrix and a nanocomposite made of the identical transparent matrix but with semiconductor inclusions of ellipsoidal shape are studied. Electrodynamic Maxwell-G...

The properties of surface polaritons as well as Dyakonov surface waves at the plane interface between a nanocomposite made of doped semiconductor spherical inclusions distributed in a transparent matrix and a nanocomposite made of the identical transparent matrix but with doped semiconductor inclusions of ellipsoidal shape are studied. Electrodynam...

Dispersion properties of surface electromagnetic waves localized at the plane interface between a nanocomposite made of a semiconductor inclusions evenly distributed in a transparent matrix and a hypercrystal, formed by an alternating dielectric and hyperbolic layers are studied. Electrodynamic Maxwell Garnett model is applied to simulate the effec...

We discuss peculiarities of bulk and surface polaritons propagating in a composite magnetic-semiconductor superlattice influenced by an external static magnetic field. Three particular configurations of magnetization, namely the Voigt, polar and Faraday geometries are considered. In the long-wavelength limit, involving the effective medium theory,...

The research is devoted to the automatic sleep stages classification based on non-invasive biosensor. A deep learning framework for classification of wakefulness, REM and NREM sleep stages (N1, N2, and N3) is proposed. The system consists of a combined convolutional and recurrent (long short-term memory, LSTM) neural network (CNN-LSTM). The propose...

Topology of isofrequency surfaces of a magnetic-semiconductor superlattice influenced by an external static magnetic field is studied. In particular, in the given structure, topology transitions from standard closed forms of sphere and ellipsoid to open ones of Type I and Type II hyperboloids as well as bi-hyperboloid were revealed and analyzed. In...

Electrodynamic properties of a photonic hypercrystal formed by periodically alternating two types of anisotropic metamaterials are studied. The first metamaterial consists of ferrite and dielectric layers, while the second metamaterial consists of semiconductor and dielectric layers. The system is assumed to be placed in an external magnetic field,...

Poster presented at 2017 IEEE First Ukraine Conference on Electrical and Computer Engineering (UKRCON)

A substantial control of dispersion features of the hybrid EH01 and HE11 modes of a circular waveguide which is completely filled by a longitudinally magnetized composite finely-stratified ferrite-semiconductor structure is discussed. A relation between the resonant conditions of such a composite gyroelectromagnetic filling of the circular waveguid...

In this report, dispersion properties of a circular waveguide filled by a composite gyroelectromagnetic structure, which consists of alternating ferrite and semiconductor layers are studied. The system is supposed to be longitudinally magnetized, i.e. the static external magnetic field is applied along the axis of the guide, perpendicularly to the...

It is demonstrated that the effect of coexistence of bulk and surface polaritons within the same frequency band and wavevector space can be achieved in a magnetic-semiconductor superlattice providing a conscious choice of characteristic resonant frequencies and material fractions of the structure's underlying components as well as geometry of the e...

Crossing and anti-crossing effects in dispersion characteristics of both bulk and surface polaritons in a magnetic-semiconductor superlattice influenced by an external static magnetic field being in the Faraday geometry are discussed. The bulk polaritons are classified as eigenwaves with right-handed and left-handed elliptically polarized states, w...

Extraordinary dispersion features of a circular waveguide filled by a longitudinally magnetized composite gyroelectromagnetic medium are studied. The composite medium is considered to be constructed by juxtaposition together of magnetic and semiconductor layers providing all characteristic dimensions of the resulting multilayered system are much sm...

Extraordinary dispersion features of both bulk and surface polaritons in a magnetic-semiconductor superlattice which is influenced by an external static magnetic field applied in the Voigt and polar geometries are revealed and discussed. It is shown that the conditions for total overlapping dispersion regions of simultaneous existence of bulk and s...

Dispersion properties of both bulk and surface polaritons at the interface between vacuum and ferrite-semiconductor superlattice are studied. The superlattice is considered to be influenced by an external static magnetic field in the Voigt geometry. In order to derive tensors of effective relative permeability and effective relative permittivity of...

Dispersion relations for both bulk and surface polaritons in a subwavelength magnetic-semiconductor structure which is placed in an external static magnetic field, applied parallel to the boundaries of the layers are studied. It has been shown that the conditions of simultaneous existence of bulk and surface polaritons in the same spectral range ca...

Extraordinary dispersion features of both bulk and surface polaritons in a finely stratified magnetic-semiconductor structure which is influenced by an external static magnetic field in the Voigt geometry are discussed in this Letter. It is shown that the conditions for total overlapping dispersion regions for the simultaneous existence of bulk and...

In the present paper we focus on the study of polarization properties of biaxial metamaterial, which consist of alternate ferrite and semiconductor layers, located on an ideally conducted metal substrate. The system is placed into an external magnetic field along the boundaries of the layers. The effective medium theory is applied. Effective linear...

In the given paper, the dispersion properties of surface electromagnetic waves at a plane interface between a homogeneous medium (vacuum) and a layered periodical structure, consisting of alternating layers of ferrite and a semiconductor, placed in an external magnetic field are studied. This structure is considered in the subwavelength approximati...

In the present paper we focus on the study of polarization properties of biaxial metamaterial, located on an ideally conducted metal substrate. The system is placed into an external magnetic field. Effective linear-to-elliptic polarization conversion has been shown, by means of physical and geometrical parameters of the system under consideration.

In this paper the electromagnetic waves propagation in a photonic crystal with an embedded inclusion of subwavelength ferrite-semiconductor periodic structure to form the defect region are investigated. The system is placed into an external magnetic field applied along layers interfaces. The numerical and analytical results by transfer matrix metho...

This paper analyzes surface waves (SW) supported by a biaxial metamaterial layer placed between two semi-infinite isotropic media. The metamaterial fabricated by periodic alternating semiconductor and dielectric layers and subjected to an external magnetic field. The magnetic field is applied parallel to the layers. We consider such structure in th...

We show that it is possible to effectively control the polarization state of the reflected electromagnetic wave (phase difference, polarization rotation angle and ellipticity) from a 1D photonic crystal, located on dielectric and semiconductor substrates by varying several system parameters: magnetic field, thicknesses of the layers, physical param...

The problem of the surface electromagnetic waves localized at the interface between vacuum and fine-stratified periodic semiconductor-dielectric structure in an external magnetic field is studied. Such a structure is defined as a biaxial crystal with effective components of permittivity which depend both on physical parameters of the structure and...

In the present paper we considered electromagnetic surface waves (SW), which localised at the interface of finite periodic metamaterial, that consists of alternate semiconductor and dielectric layers. The structure was placed into an external magnetic field. It has been shown that it is possible to effectively control the parameters of SW (namely p...

The properties of terahertz surface waves (SW's) in the finite semiconductor-dielectric periodic structure in an external magnetic field were investigated. The band structure of the considered periodic material was analyzed (Fig. 1). Analytical and numerical calculations of the dispersion relation for SW's were carried out. The distribution of elec...

The specific features of TM-polarized surface electromagnetic waves in a finite structure fabricated by a periodic alternating semiconductor and dielectric layers are investigated. Dispersion characteristics of eigenwaves are analyzed numerically and analytically. The complex Poynting energy flux and the surface wave's distribution are calculated....

Propagation of electromagnetic waves in a structure formed by periodically alternating semiconductor and dielectric layers is studied for the case where an external magnetic field is applied parallel to the boundaries of the layers. The expressions for effective permittivity were obtained in the long-wave limit. It was shown that, investigated stru...

The conditions for the existence of surface electromagnetic waves at the planar interface between a homogeneous medium (vacuum) and a thin-layer periodic structure consisting of alternating semiconductor and dielectric layers in an external magnetic field have been investigated. This structure represents an optically biaxial crystal with the effect...

Conical refraction phenomenon in a fine-stratified structure was studied. The structure was fabricated by periodic alternating dielectric and semiconductor layers and was exposed into an external magnetic field parallel to the boundaries of the layers and perpendicular to the plane of incidence. The expressions for effective permittivity were obtai...

The propagation of electromagnetic waves along the optical axes of a thin-layer periodic semiconductor-dielectric structure in an external magnetic field (i.e., under conditions of external and internal conical refraction) has been investigated. It is shown that the conditions for conical refraction can be implemented in certain regions by changing...

Propagation of electromagnetic waves in a structure formed by periodically alternating semiconductor and dielectric layers is studied for the case where an external magnetic field is applied parallel to the boundaries of the layers. The expressions for effective permittivity were obtained in the long-wave limit. It was shown that, investigated stru...

Electromagnetic wave polarization is analyzed in the case of reflection from a thin-stratified semiconductor-dielectric periodic structure situated on a metal substrate in an external magnetic field. It is shown that the polarization ellipse parameters, specifically, the length and angle of inclination of the ellipse axes with respect to the coordi...

Reflection and transmission of light by a bounded periodically layered structure formed by periodically repeated dielectric and semiconductor layers in a magnetic field are studied. The period of the structure is assumed to be much shorter than the wavelength. The magnetic field vector is parallel to the layer plane, and the wave propagation direct...

Conical refraction phenomenon in a fine-stratified structure was investigated. The structure was fabricated by periodic alternating dielectric and semiconductor layers and was exposed into an external magnetic field. It has been shown that such structure represents a biaxial crystal. The dependences of aperture angle of an internal conical refracti...

Reflection of a plane electromagnetic wave from the fine-stratified structure located on a metal substrate is considered. A number of features caused by specific properties of effective permittivity are arises. It has been shown, that dependences on a frequency and magnetic field allow to change polarizing characteristics (field ellipticity).

In this paper we can conclude that dependences on a angle of incidence, frequency and external magnetic field allow to determine presence of allowed and forbidden zones, and also to analyze properties of the layers forming structure. Besides, change of a magnetic field allows "to operate" by the optical properties of the structure.