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The effect of the size and relative permittivity of the isotropic filling on the condition under which the circular waveguide with a co-axially positioned latching ferrite cylinder of azimuthal magnetization and a dielectric toroid exhibits properties of a nonreciprocal digital phase shifter, working in the normal TE01 mode, is examined. The discussion is focused on the case in which the relative...
A circular waveguide with a ferrite cylinder of azimuthal magnetization and a dielectric toroid, propagating normal TE0n modes, is considered. An original authors' method, elaborated previously for computation of the positive purely imaginary roots of its characteristic equation, derived by complex Kummer confluent hypergeometric and real Bessel and Neumann functions, is employed. A numerical analysis...
Increased particulate matter (PM) concentration in big cities and agglomerations is one of the main risk factors for the health of the residents. Conventional systems for PM monitoring have significant limitations, especially with respect to the costs for installation and maintenance. The number of these monitor stations is limited but PM concentration changes fast, non-linearly, within wide limits...
A novel comparator based on popular self-biased complementary CMOS solution is presented and examined. Its current consumption does not depend on the process variations, the supply voltage and the temperature. This is achieved by using a replica biasing. It can provide output currents during switching, which are larger than its quiescent current, like the adaptive-biasing solutions. Simulations of...
The theorem for existence of the G2 (c, ρ, n) numbers (c — a positive integer, ρ — real, positive, 0 < ρ < 1 and n — a natural number, c, n — bounded) is advanced and proved numerically. It could be looked upon as a definition of the same and determines each of them as the finite real positive limit of certain infinite sequence of real numbers, whose terms are pieced together through the medium...
This paper presents a methodology for parameters extraction of photovoltaic cell based on real measurement. The modeling of equivalent schemes of solar cells is of great importance in order to be included in electric circuits for wireless sensor networks power supply. The parameters extraction of these devices is still a very difficult task, which requires experimental data, computing and modeling...
One of our most vital resources nowadays is fresh water. Water quality refers to the condition of the water, including chemical, biological and physical characteristics with respect to its suitability for a particular purpose. The main purpose of this publication is to set up a virtual system for water analysis in order to measure particular parameters of the water before and after physicochemical...
Decline of environmental noise and subsequent pollution are one of the most important purposes for citizens, scientists and public representatives nowadays. Many European legislative initiatives and studies deal with environmental noise monitoring. The enabling factor for this ongoing development is the availability of low-cost and low-power devices for sensing, computing and communication. Systems...
Spoken dialogue systems must be able to recover gracefully from unexpected user inputs. In many cases, these unexpected utterances may be within the scope of the system, but include previously unseen phrases that the system cannot interpret. In this work, we augment a spoken dialogue system with the ability to learn about new concepts by conversing with the user in natural language. We present a novel...
This paper presents a LabVIEW based system of acquisition, processing and analysis of ECG (electrocardiogram) signals. Biomedical signal acquisition has made great advances in recent years due to the introduction of modern hardware and software technologies. Computer based signal processing systems are becoming an efficient approach for acquisition and analyzing of such signals. In our implementation...
The water quality analysis is important for human health and environmental protection. There are many physical and chemical methods for such analysis, with different accuracies, complexity and time consumption. In the presented paper, a colorimetric method, based on virtual instrumentation is suggested and considered in details. At the end of the paper, the concentration of free chlorine in water...
A novel method for removing multiple switching at the edges of digital signals based on a comparator with dynamic hysteresis is presented. The proposed concept is analytically investigated and a CMOS circuit is designed based on the obtained results. Simulations with Spectre simulator demonstrate its correct operation.
A method for finding the positive purely imaginary roots of the characteristic equation of the circular waveguide with a dielectric cylinder and a ferrite toroid of azimuthal magnetization that supports normal TE0n modes, derived by complex Kummer and Tricomi confluent hypergeometric and real Bessel functions, is elaborated. Using it, a numerical analysis is done of the effect of the modulus of off-diagonal...
A novel numerical technique for calculating the differential phase shift, brought forth by the circular waveguide, containing a ferrite cylinder of azimuthal magnetization and a dielectric toroid that supports normal TE0n modes, is worked out. It is based on the method of successive approximations and yields the roots α1 and α2 (|α1| ≤|α2)| of a biquadratic equation, connecting the off-diagonal ferrite...
The theorem for existence and for the main features of the T1(L,n) numbers (finite real positive numbers, near of kin to the positive zeros Oη,nL in the independent variable ρ of the generalized in the Thompson and Barnett's sense real regular Coulomb wave function FL(η,ρ) with ρ, η and L - all real, ρ > 0, −∞ < η < +∞ and L - finite, and n = 1,2,3…), is formulated by means of three lemmas...
The condition under which the circular waveguide, loaded with a co-axial latching ferrite cylinder of azimuthal magnetization, surrounded by a dielectric toroid, exhibits properties of a nonreciprocal digital phase shifter for the normal TE01 mode, is investigated. For simplification it is assumed that the relative permittivities of the two layers are equal. Sophisticated iterative techniques are...
The real negative zeros equation and equation — a finite positive integer) in the first parameter k̂, resp. â of the real Kummer confluent hypergeometric function equation with â, ĉ and x̂ — all real, â < 0, ĉ > 0 and x̂ > 0, â = ĉ/2 + k̂ (k̂ = â – ĉ/2 — real, negative, −∞ < k̂ < −ĉ/2 ), resp., â — arbitrary real negative, are investigated numerically for selected values of n̂, assuming...
Air pollution is both an environmental and a social problem, as it leads to a multitude of adverse effects on human health, ecosystems and the climate. Air pollution is one of the largest environmental health risks in Europe today. Quality of the air in city and urban areas is the most important factor that directly influences the incidence of diseases and decreases the quality of life. Taking appropriate...
Noise pollution in urban environments is a common problem that affects people's health and quality of life. It is therefore one of the main issues addressed in many studies of environmental noise level assessment. The equivalent sound pressure level (LAeq) is one of the most widely used indicators for evaluating environmental noise from roads, railways, and industry. According to the European framework...
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