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The main goal of this numerical and experimental study of composite armour systems was to investigate their ballistic behaviour. Numerical simulations were employed to determine the initial dimensions of panel layers before the actual ballistic test. In order to achieve this aim, multivariate computations with different thicknesses of panel layers were conducted. Numerical calculations were performed...
The main purpose of the study is an assessment of computational efficiency of selected numerical methods for estimation of vibrational response statistics of a large multi-bearing turbo-generator rotor-shaft system. The effective estimation of the probability distribution of structural responses is essential for robust design optimization and reliability analysis of such systems. The analyzed scatter...
The positivity of a class of fractional descriptor continuous-time nonlinear systems is addressed by the use of the Weierstrass- Kronecker decomposition of the pencil of linear part of nonlinear system. Sufficient conditions for the positivity are established and illustrated by an example of fractional continuous-time descriptor nonlinear systems.
This paper presents several methods that enable the reduction of power loss in the auxiliary resonant commutated pole inverter - ARCP. Presented methods can be divided into static and dynamic ones. The static methods are related to an appropriate design of the inverter, whereas dynamic ones to advanced control of the power transistors. A variety of design and control methods are presented together...
The paper presents investigation results concerning assessment of the Polish Power System (PPS) angular stability based on power system state matrix eigenvalues associated with electromechanical phenomena, when using the angular stability factors calculated on the basis of these eigenvalues. The eigenvalues were calculated by analysis of the disturbance waveforms of the instantaneous power, angular...
This paper presents a method that uses the coefficient of variation (COV) of pressure in a diesel engine combustion chamber to determine the crank angle degree (CAD) for which the heat release rate (HRR) reaches the maximum value. The COV was proposed for determining the point corresponding to the angle of start of combustion (SoC). Regression models were fit with these descriptors for the engine...
The paper presents the principle of the operation of a spectropolarimetric interferometer. In a planar waveguide orthogonal modes of the TE and TM types can be excited for the entire visible light. During the propagation the difference of the phases between the modes was determined, which is the function of the length of the path of propagation, the difference of the effective refractive index (NTM-NTE)...
Most estimators of the shape parameter of generalized Gaussian distribution (GGD) assume asymptotic case when there is available infinite number of observations, but in the real case, there is only available a set of limited size. The most popular estimator for the shape parameter, i.e., the maximum likelihood (ML) method, has a larger variance with a decreasing sample size. A very high value of variance...
The paper presents the study of combustion process of a homogenous lean propane-air mixture in the cylindrical combustion chamber ignited by a hot gas jet from the pre-ignition chamber. A rich propane-air mixture in the pre-chamber is ignited by the spark plug and the exhaust gasses flow from the chamber trough the holes in the wall. The mathematical model of gas exchange and energy balance in chambers...
This paper describes a new measurement method for determining the quality of the IPTV (Television over IP) service. This method uses the latest IPTV Model and is one of a number of parameter-based measuring techniques (offline operation, i.e. without intrusive measurement). It delivers results that come very close to those of the corresponding Perceptual Evaluation of Video Quality (PEVQ) curves....
A method of checking coherence of comparison results of primary DC voltage group standards is described in the paper. Usefulness of the proposed method was proved by coherence investigation of DC voltage group standard kept in the Central Military Calibration Laboratory (CWOM, Warsaw, Poland). Results obtained for the group of five Fluke DC voltage standards prove very good coherence of voltage differences...
The article presents some possibilities of same type radar copies identification with the use of graphical representation. The procedure described by the authors is based on transformation and analysis of basic parameters distribution which are measured by the radar signal especially Pulse Repetition Interval. A radar intercept receiver passively collects incoming pulse samples from a number of unknown...
In this paper, we examine whether a quantum computer can efficiently simulate quantum processes such as the tunnel effect. We examine a quantum algorithm that calculates the value of transition and reflection coefficients for the Gaussian wave packet scattered on a rectangular potential. We compare the results obtained in this way with the results of classical simulations and analytical calculations.
In this paper, the problems of finite-time stability and stabilization for a class of singular time-delay systems are studied. Using the Lyapunov-like functional (LLF) with (exponential or power) weighting function and a new estimation method for the lower bound on LLF, some sufficient stability conditions are introduced. It is shown that the weighting function significantly reduces the conservatism...
In the study, the mechanical and microstructural properties of friction stir welded EN AW-6060 Aluminum Alloy plates were investigated. The friction stir welding (FSW) was conducted at tool rotational speeds of 900, 1250, and 1500 rpm and at welding speeds of 100, 150 and 180 mm/min. The effect of the tool rotational and welding speeds such properties was studied. The mechanical properties of the...
This paper presents the analysis of the effect of differential signal coupler positioning accuracy on its high frequency performance parameters for contact-less high speed chip-to-chip data transmission on PCB application. Our considerations are continuation of the previous works on differential signal coupler concept, design methodology and analysis for high speed data transmission monitoring. The...
The potential of Quantum Cascade Laser technology has been recently harnessed in industry, medicine and military to create a range of original infrared gas sensors. These sensors have opened up many new applications due to compact size, excellent sensitivity, robust construction and low power requirements. They rely on infrared absorption spectroscopy to determine identity and quantity of gases. The...
This article describes the influence of an inclined magnetic field on the mixed convective peristaltic transport of fluid in an inclined channel. Two types of non-Newtonian fluids are considered. The problem formulation is presented for the Eyring-Prandtl and Sutterby fluids. Viscous dissipation and Joule heating in the heat transfer process are retained. The presence of a heat source in the energy...
In this paper three simplified forms of the fractional-order (FO) backward difference (BD) are proposed and analysed. Due to time and frequency characteristics criteria parameters of simplified forms of the FOBDs are chosen. Applications of the simplified forms of the FOBDs diminish a number of multiplications and additions needed to evaluate the FOBD. This is very important in real-time microprocessor...
This study aimed at the simulation of bone tissue remodeling within a bone defect with the utilization of the finite element method (FEM), enabling - via elaborated application - objective evaluation of orthodontic forces which positively influence periodontium in vivo. The initial position of each bracket on the passive archwire was registered, and then a geometrical and discretemodel of the appliance...
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