Search

In this paper, the potential of reducing the electricity cost with the help of energy storage and controllable loads on the Russian retail electricity market is studied. The retail electricity market in Russia features different price categories, allowing consumers to reduce expenses with proper planning. Approximately 2/3 of the cost in flexible price categories is for the power consumption in specific hours, with the remaining 1/3 for the energy consumption itself. Because of the continued cost decrease of energy storage devices, they have become an increasingly more attractive investment, opening opportunities for economic savings combined with load shifting, which can occur either in a standalone manner or with the use of energy storage. In this paper, demand shifting is implemented in the Russian retail market, combined with the payback calculation for energy storage.

In this work, we compared the performance of the ordinary Newton-Raphson method for calculating power flows against three quasi-Newton methods: chord, “good” and “bad” Broyden's methods. First, we illustrated compared the performance of each method on systems of equations of different sizes. Secondly, we compared these methods on power flow calculation for grids of different sizes. We found that an ill-suited initial approximation strongly affects the quasi-Newton methods and makes them slower than the Newton-Raphson one. Finally, in order to fix this issue, we introduced a mixed-method: a few iterations of Newton-Raphson are used to determine a more accurate initial approximation, which can then be used in quasi-Newton methods. Numerical tests showed that this approach outperforms ordinal Newton-Raphson and quasi-Newton methods.

The paper examines the process of aerial vehicle coordinates detection using the multilateration radio system. Spatial diversity of multilateration system under investigation is achieved by single transmitting node and array of anchor nodes. The original results and findings are as follows: detection at the receiver node position of azimuth angles between aerial vehicle and signal irradiated by transmitter. The following procedure is used to determine co-operative range measurement, radial velocity and relative cartesian coordinates of object of interest and vector velocities of aerial vehicle.

One of the most important stages in the development of a wheeled vehicle motion control system are the development and testing of control algorithms. We consider it expedient to replace the road tests of the system by simulating the movement of the wheeled vehicle in real time for a preliminary assessment of its workability. Previously, a mathematical simulation of the controlled motion of the wheeled vehicle was carried out to verify the model adequacy to a real object. The control algorithm is based on predicting the position of the wheeled vehicle by means of a predetermined forecast time and consists of global and local regulation. The global control by use the deviation from the specified trajectory determines the angle of rotation of the steered wheels, providing movement along the specified trajectory. Local regulation provides the implementation of the specified value of the angle of turn of the steered wheels. The equipment complex provides the registration and generation of the necessary parameters for the operation of the control system in real time. The tests were carried out at the experimental stand "steering -front suspension of the vehicle." Turning the front controlled wheels to the desired angle was carried out by an electromechanical steering correction mechanism. Motion along straight and curved trajectories was simulated with and without disturbances from the reference surface. According to the results of the experiments, it was found that the implemented control algorithm provides movement.

It is reported an enhancement of the transverse magneto-optical Kerr effect (TMOKE) in the vicinity of the excitonic and hybrid plasmon-exciton modes. Such modes are excited in quantum well in the bare diluted semiconductor thin films and in the plasmonic semiconductor nanostructures. Two-order enhancement of the TMOKE is observed in bare semiconductor films in the spectral region of the excitonic resonances. In plasmonic semiconductor nanostructures with quantum wells we also observe the hybridization of the TMOKE spectrum due to excitation of plasmon-exciton modes.

Topological properties play a fundamental role in many physical phenomena. One of the examples from condensed matter physics is the recently discovered, novel, nontrivial phase of matter called topological insulators. Alternatively, photonics offer a unique platform for emulation of condensed matter systems in a simple and controllable way. Recently, there has been a burst of interest in exploring topological orders with photons, with the discovery of a new class of nontrivial states in photonic topological insulators. Here, we present our recent experimental and numerical results devoted to the observation of photonic topological edge states in electromagnetic structures.

© 2017 Institute of Electrical and Electronics Engineers Inc. All rights reserved. We propose and demonstrate a new method for the characterization of nonlinear multimode integrated devices that reconstruct the biphoton state produced trough spontaneous parametric down-conversion (SPDC) using classical sum-frequency generation measurements. The proposed method is experimentally demonstrated by predicting the state generated from a multi-channel integrated nonlinear waveguide device.

All-dielectric and semiconductor nonlinear nanophotonics is an emerging field enabling efficient optical interactions between magnetic and electric resonances at sub-wavelength scales, thereby achieving high directionality and high figures of merit due to very low losses [1, 2]. It was shown that AlGaAs nanodisks with quadratic nonlinear susceptibility can provide second harmonic generation (SHG) with record-high efficiency of 10−4 [3], opening to a wide range of possible applications, including nonlinear microscopy and holography. In this work, we show experimentally that the strong quadratic nonlinearity in AlGaAs nano-disks allows efficient sum-frequency generation (SFG) with nontrivial polarization dependencies. By using the established classical-quantum analogy [4], we predict that these nano-resonators can facilitate efficient generation of quantum entangled photon pairs with higher than kHz biphoton rate and strong angular correlations.

We discuss bulk and edge states of bound photon pairs supported by the one-dimensional array of nonlinear optical cavities for the two scenarios: (i) dimer array consisting of identical cavities with the two types of tunneling constants and with on-site Kerr-type nonlinearity; (ii) simple array of identical cavities with both on-site nonlinearity and nearest neighbor nonlinear interaction. It is demonstrated that both structures can support interaction-induced edge states of bound photon pairs. We analyze the properties of such exotic states thus providing the insights into the emerging field of nonlinear topological photonics.

We reveal that the unique properties of ultrathin metasurface resonators can improve dramatically magnetic resonance imaging (MRI). We place a metasurface formed by an array of metallic wires inside a scanner under the studied object and achieve a substantial enhancement of the radiofrequency magnetic field by means of subwavelength near-field manipulation with metasurface, also allowing to improve scanner sensitivity, signal-to-noise ratio (SNR), and image resolution.

Metamaterials are composite structures designed to produce the properties which are not available in nature and control electromagnetic waves in any desirable ways. A special class of wire metamaterials consists of periodic arrays of parallel conducting wires (the so-called wire medium), and they provide many opportunities to shape the form of electromagnetic field being especially promising for Magnetic Resonance Imaging (MRI) applications. In this work, we discuss how to efficiently use an annular wire metamaterial resonator in order to enhance and redistribute electromagnetic fields in 1.5 Tesla MRI.

We present an experimental study of the magnetic Purcell effect in finite arrays of the wire metama-terial. By directly measuring the spatial-frequency map of the Purcell factor we explicitly demonstrate how the Purcell factor is enhanced at the Fabry-Perot resonances of the wire metamaterial block in microwave frequency range. The experimental results are in a good agreement with theoretical and numerical estimations.

We investigate the effect of the self-induced torque in metamaterials. The essence of the effect is that an electric dipole placed in anisotropic structure experiences a torque arising from the response of the structure polarized by the field of the test dipole. We perform rigorous calculations basing on the discrete dipole model and examine the domain of validity of the effective medium approximation by comparison of the rigorous results with approximate ones.

It is shown, that rating system for knowledge assessment (RSKA) allows comparing self-estimation with estimation by others so that there were no internal and external conflicts. The system expands opportunities of personal development. It allows communicate closely at an interpersonal level. At such dialogue: -necessary information exchange is achieved; -personal outlook is formed; For adequacy of self-estimation the feedback between persons trained and training is important. The energy-information exchange with people around allows making break in sphere of special opportunities, to understand the world, to realize the place in it, and also problems which the person faces. It is impossible to achieve high quality of knowledge and skills without application of psychological methods, without change of the approach for comprehension and processing of new information by the person.

Lecture classes are mass actions. During lecture the teacher works with all students simultaneously. He does not pick out single persons. Personal work is carried out at individual classes. Only there it is possible to carry out in full the feedback between the student and the teacher. The technique of conducting laboratory works is introduced. It is shown, that the rating system of knowledge assessment allows the student to compare self-estimation with estimation of his knowledge by others. Thus internal and external conflicts are excluded, and the opportunities for personal development appear. In order to provide self-estimation adequacy the feedback between the teacher and the student is important.

It is suggested to use knowledge transplantation method for students' creative abilities promotion and for solution of complicated scientific-and-engineering problems.

Specific features of the rating system for knowledge assessment have been considered. Possible variants of the rating system have been shown, along with brief characteristics and drawbacks. It is recommended to apply "hard" rating for maximum stimulation of educational process

We study the fundamental properties of all-dielectric metamaterials composed of high-index dielectric rods. We vary the value of rod permittivity from low to high, and analyze a crossover between photonic crystals and metamaterials observed in the scattering features associated with the Bragg and Mie resonances. We reveal new features of the collective response in the scattering which can be explained by the physics of Fano resonances.

We demonstrate how the medium with the hyperbolic isofrequency surfaces in the wavevector space can be realized by two-dimensional artificial transmission lines. The peculiar character of wave propagation in such a hyperbolic medium is visualized by the study of the cross-like emission pattern of a current source. Our results are supported by the direct solution of the Kirchhoff equations and an analytical theory.

For silver recovery from the fixing and bleaching solution as an example, the dynamics of filling the porous cathode with the metal is investigated experimentally for processing one large portion of solution or several small ones. It is shown that in the absence of an oxidant it is admissible and even desirable to divide the solution into several small portions because in this case the distribution of the metal over the electrode depth is somewhat improved, and the final mass of the deposited metal is larger. However, in the presence of an oxidant solution partitioning causes the dissolution of silver inside the porous electrode during processing the second and subsequent portions and has unfavorable effect on the final distribution of the metal and on its final mass.

The influence of different ratios of the rates of metal deposition at the initial and metal-coated surface of the non-equipotential porous matrix on the dynamics of its filling with the metal is investigated using numerical calculations. It is shown that an increase in the deposition rate on the regions coated with metal layer causes an increase in the time of PE filling with the metal and leads to substantial changes in the dynamics of deposition process, in good qualitative agreement with the experimental data.

Rates of spontaneous optical intraband transitions are determined. Huang-Rhys factor controlling the hole relaxation is calculated. The rate of hole relaxation due to the emission of multiple optical phonons is estimated. A new mechanism of electron nonradiative relaxation is proposed. This work was supported by RFBR and the ldquoDynastyrdquo Foundation - ICFPM.

With the help of previously developed dynamic model of porous electrode (PE) with high initial conductivity, we investigate the effect of flow rate (0.05-10 cm/s) and direction of solution flow (rear and front feed, as well as flow reversal) on the dynamics of metal electrodeposition inside the porous matrix. It is established that with an increase in flow rate the final mass of metal m/sub k/ inside the PE increases by a factor of 2-3; this dependence is nonmonotonous and has a maximum in the region of medium flow rates, which is most clearly exhibited for the rear feed (additional increase in % by a factor of 1.5-2). The m/sub k/ values are in good correlation with the measure of metal distribution uniformity: the more uniform is distribution of the deposit inside the PE, the larger is m/sub k/, for other conditions being the same. Within the area of high and very low flow rate, m/sub k/ is independent of the flow direction. In the former case, the profiles of metal distribution almost coincide, while in the latter one they are mirror-opposite. The highest effect of flow direction is observed for medium flow rates. Because of this, under these conditions it is reasonable to apply flow reversal in order to improve the uniformity of metal distribution and its final mass (an increase in m/sub k/ by 20-30%). For high flow rate, reversal does not give effect, while for low rates maximal relative effect is observed (a 2-fold increase); however, absolute m/sub k/ values are not large.

In this paper the problems of design of subscriber's passive antenna for cellular communication systems are considered. Antennas assembly design and its basic specification were considered. Stable communication realization is performed by means of rebroadcasting transmitters (RT). They consist of two-directional amplifier and two antennas-internal and external