The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Presently, we investigate the influence of the extent of a ring of exceptional points on the Q-factor of three-dimensional photonic crystal slabs. By changing the thickness of the slab, the extent of the ring of exceptional points is varied, allowing us to recover the Dirac cones in open, non-Hermitian systems. In this case, three bound states in the continuum are exhibited close to the Γ-point. For...
Accidental Dirac cones of linear dispersion can occur in photonic crystal (PhC) structures [1]. These configurations can be easily manufactured providing an accessible platform for studying topological properties of Dirac cones and their influence on light-matter interactions. Recently, it has been shown that when the system becomes non-Hermitian, e.g. it is an open system exhibiting radiation losses,...
This paper discusses different ways to obtain an auxiliary power supply (APS) to a solid state transformer (SST) that utilizes the modular AC-DC-DC-AC configuration. A local distributed source, that consists of two APS per module, one for medium voltage (MV) side and another one for low voltage (LV) side is proposed. For the MV side the use of a high-voltage gain static converter is necessary while...
We investigate the ability of surface impedance mantle cloaks for cloaking of elliptical cylinders excited by an electric line source. The exact analytical solution of the problem utilizing Mathieu functions is obtained and is used to derive optimal surface impedances to cloak a number of configurations. Specifically, theoretical designs are presented which can minimize the scattering from line source...
This work presents an analytical treatment of an asymmetric metamaterial-based resonator excited by an electric line source, and explores its beam shaping capabilities. The resonator consists of two concentric cylindrical material layers covered with an infinitely thin conducting shell with an aperture. Exact analytical solution of the problem is derived; it is based on the n-series approach which...
High rate pulsed DC magnetron sputtering has been used to fabricate thin film CdTe photovoltaic devices. Fabrication of thin film photovoltaic devices using magnetron sputtering has the advantages of excellent coating uniformity and use of lower substrate temperatures during deposition. The CdTe and CdS layers were deposited from compound targets. The substrates were held at 200°C during deposition,...
A second programming language should be considerably easier to learn because the programmer has built up a knowledge base of language-independent stereotypic structures and rules for handling commonly needed programming tasks (e.g., processing a list, branching, keeping a running total). However, transference of this underlying goal/plan knowledge is more complex for an unconventional language such...
The area of passive and active nano-antennas has recently attracted great attention due to their potentials in a large variety of applications. Numerous designs were proposed; both the traditional ones, inspired by their microwave counterparts, as well as those making extensive use of metamaterial and plasmonic structures. In regards to the latter, extensive analytical and numerical investigations...
In the paper a novel fuzzy sliding mode control structure is proposed. The main controller is a TSK controller whose control surface is divided into local models. In the local models located further from the equilibrium point the control lows have the form of classical sliding mode controller. The sector specified as an origin is described as a function of classical PI controller. Due to the special...
Although the cadmium chloride treatment is an essential process for high efficiency thin film cadmium telluride photovoltaic devices, the precise mechanisms involved that improve the cadmium telluride layer are not fully understood. The treatment parameters have a narrow window, deviating from these even slightly can be detrimental to cell performance. In this investigation we apply advanced microstructural...
The aim of this investigation is to apply advanced microstructural characterization techniques to study the effect of the cadmium chloride treatment on the physical properties of cadmium telluride solar cells deposited via close-spaced sublimation (CSS) and relate these to cell performance. A range of techniques have been used to observe the microstructural changes as well as the chemical changes...
Accurate measurement of the thickness of transparent and semi-transparent thin films is important in all thin film photovoltaic technologies. Surface roughness measurements are also important to interpret the performance of photovoltaic devices. Here we report on a new capability for coherence correlation interferometry that enables it to provide thin film thickness measurements with comparable accuracy...
Surface metrology plays an important role in the development and manufacture of photovoltaic cells and modules. Coherence Correlation Interferometry (CCI) is a non-contacting surface metrology tool with potentially important applications in the characterization of photovoltaic devices. Its major advantages are that it is fast, non-destructive and it takes its data from a relatively large and hence...
The article presents features of an innovative system that provides data collection of services provided by medical laboratories. System has been developed based on Java Enterprise Edition platform with usage of Spring and Hibernate frameworks combined with jQuery library.
The directed transfer function was estimated from the time-varying multivariate autoregressive model computed by means of Kalman filter. The performance of the method was tested by means of simulations. The Kalman filter method was compared with the sliding window approach used in estimation of Short-time Directed transfer Function. Both method gave similar results, however the application of Kalman...
The paper describes the possibility of using high-efficiency motors to fans mill drives. Criteria for economic analysis of replacing standard motors by energy-saving ones are quoted. The results of this analysis are presented. Mathematical models of induction motors for dynamic tests are briefly described. Simulation and measurement results of start-up for standard and energy-saving motors used in...
All data are not created equal. Individual data sets vary from each other in a multitude of ways - from easily measured ways such as size, format, and complexity; to ways that require a more nuanced understanding, such as in the breadth and depth of a data set's potential user base, its "designated community" to use the terminology of the Reference Model for an Open Archival Information...
We studied the dynamical pattern of transmission involved in the information processing during cognitive experiments engaging working memory. The ensemble averaging approach was used to fit a multichannel autoregressive model to the EEG signals recorded during the transitive reasoning task. The short-time directed transfer function was estimated for finding dynamical patterns of functional connectivity...
In this paper implementation of neural network based estimator of the load machine speed for two-mass drive system on a reconfigurable field-programmable gate array (FPGA) is presented. Due to such implementation, the developed neural estimator performs the parallel signal processing and thus the realization time is much shorter than using classical DSP. The FPGA based neural network structure has...
The article presents the learning management system for SCORM based e-learning courses. The key feature is usage of modern technologies to implement system based on SCORM specification. The application is built on Java Enterprise Edition (JEE) technology.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.