Search results for: density calculation
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Dynamics of fault arc traveling along busbars in high voltage switchboards = Dynamika łuku zwarciowego przemieszczającego się wzdłuż szyn rozdziel-nic wysokiego napięcia
PublicationThe paper presents the results of magnetic induction and electrodynamic force calculations acting on arc column during short-circuit in medium voltage air-insulated bus-bars. The gap between the bars was 120 mm and the prospective short-circuit currents ranged from 4 kA to 8 kA. The paper also shows the measurement results of average velocity fault arc depending on currents arc diameter and arc current was established and described....
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Efficient model order reduction for FEM analysis of waveguide structures and resonators
PublicationAn efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...
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Design and distribution of air nozzles in the biomass boiler assembly
PublicationDue to energy crisis as well as increasing pollution of the environment, renewable energy sources usage increases all over the world. These facts encouraged authors to start research over developing a uniform biomass boiler calculation model. This paper presents a design of biomass boiler assembly created for ORC (Organic Rankine Cycle) unit since these systems could achieve strong position in energy industry....
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Examples of numerical simulations of two-dimensional unsaturated flow with VS2DI code using different interblock conductivity averaging schemes
PublicationFlow in unsaturated porous media is commonly described by the Richards equation. This equation is strongly nonlinear due to interrelationships between water pressure head (negative in unsaturated conditions), water content and hydraulic conductivity. The accuracy of numerical solution of the Richards equation often depends on the method used to estimate average hydraulic conductivity between neighboring nodes or cells of the numerical...
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Field tests on hydrodynamic and hybrid operation of a bi-directional thrust bearing of a pump-turbine
PublicationIn vertical shaft pump turbines operating in pumped storage power plants an important role is played by a thrust bearing. Because of bi-directional character of operation, thrust bearing tilting pads have to be supported symmetrically, which is known to be unfavourable from the point of view of their performance. Large thrust bearings have to be carefully designed so as to minimise excessive thermo-elastic pad deformations. The...
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Fundamental Schemes to Determine Disjoint Paths for Multiple Failure Scenarios
PublicationDisjoint path routing approaches can be used to cope with multiple failure scenarios. This can be achieved using a set of k (k> 2) link- (or node-) disjoint path pairs (in single-cost and multi-cost networks). Alternatively, if Shared Risk Link Groups (SRLGs) information is available, the calculation of an SRLG-disjoint path pair (or of a set of such paths) can protect a connection against the joint failure of the set of links...
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Non-Least Square GNSS Positioning Algorithm for Densely Urbanized Areas
PublicationThe paper introduces an essentially new algorithm for calculating the GNSS position as an alternative to the least-square method. The proposed approach can be widely applied to any positioning method that uses multiple position lines for position calculation and is an example ofhow using a numerical solution can improve position accuracy without access to historical data. In essence, the method is based on the adaptation of the...
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Determination of the Theoretical and Actual Working Volume of a Hydraulic Motor—Part II (The Method Based on the Characteristics of Effective Absorbency of the Motor)
Publication: In this article, the second method of determination of the theoretical and actual working volume of a hydraulic motor is described. The proposed new method is based on the characteristics of effective absorbency of the motor. The effective absorbency has been defined as the ratio of flow rate in a motor to the rotational speed of the motor’s shaft. It has been shown that the effective absorbency is a nonlinear function of the...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading,...
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The efficiency of turbomachinery in the zero-and three-dimensional approaches
PublicationEfficiency of turbomachinery is usually defined using an isentropic process. This approach provides a reliable reference point only when pressure and temperature measurements are available, e.g. at the casing inlet and outlet. In the case of a single stage internal efficiency determination the reference point is difficult. Computational fluid dynamics allows for an exact calculation of values of losses occurring in a turbine...
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Numerical Modelling of Forced Convection of Nanofluids in Smooth, Round Tubes: A Review
PublicationA comprehensive review of published works dealing with numerical modelling of forced convection heat transfer and hydrodynamics of nanofluids is presented. Due to the extensive literature, the review is limited to straight, smooth, circular tubes, as this is the basic geometry in shell-and-tube exchangers. Works on numerical modelling of forced convection in tubes are presented chronologically in the first part of the article....
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Analytical Estimation of Power Losses in a Dual Active Bridge Converter Controlled with a Single-Phase Shift Switching Scheme
PublicationMicro-grid solutions around the world rely on the operation of DC/DC power conver- sion systems. The most commonly used solution for these topologies is the use of a dual active bridge (DAB) converter. Increasing the efficiency and reliability of this system contributes to the improvement in the stability of the entire microgrid. This paper discussed an analytical method of energy efficiency and power loss estimation in a single...
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Computer-aided evaluation of the railway track geometry on the basis of satellite measurements
PublicationIn recent years, all over the world there has been a period of intensive development of GNSS (Global Navigation Satellite Systems) measurement techniques and their extension for the purpose of their applications in the field of surveying and navigation. Moreover, in many countries a rising trend in the development of rail transportation systems has been noticed. In this paper, a method of railway track geometry assessment based...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.0, b=0.11) and (C=5.7, b=0.32) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=2.1, b=0.14) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.1, b=0.14) and (C=5.7, b=0.32) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.0, b=0.11) and (C=2.1, b=0.14) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.5, b=0.37) and (C=5.7, b=0.32) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.1, b=0.14) and (C=5.5, b=0.37) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.0, b=0.11) and (C=5.5, b=0.37) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=2.0, b=0.11) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=2.1, b=0.14) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=5.5, b=0.37) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=2.0, b=0.11) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=5.7, b=0.32) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.8, b=0.25) and (C=5.7, b=0.32) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=5.5, b=0.37) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=2.4, b=0.26) and (C=2.8, b=0.25) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two directional control valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first DCV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=4.40, b=0.42) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.30, b=0.38) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=4.40, b=0.42) and (C=5.30, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=4.40, b=0.42) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=3.30, b=0.40) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=6.20, b=0.38) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=3.30, b=0.40) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.30, b=0.38) and (C=3.30, b=0.40) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=3.30, b=0.40) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.30, b=0.38) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=4.40, b=0.42) and (C=3.30, b=0.40) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=4.40, b=0.42) and (C=6.40, b=0.45) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=6.40, b=0.45) and (C=7.30, b=0.49) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=5.30, b=0.38) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Determination of flow properties of a serial connection of two pneumatic elements with (C=6.40, b=0.45) and (C=6.20, b=0.38) from changes in air pressure in a tank being emptied
Open Research DataThe aim of the study was to determine the flow properties of serial connection of pneumatic components.The experiments were to measure the pressure changes in a being emptied tank for two pressure relief valves arranged in-line. Four test configurations were used: (1) being emptied tank -> the first PRV -> ambient atmosphere, (2) being emptied...
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Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych
PublicationIn this paper a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid) has been presented. A conception of a dual-stator hybrid exciter has been proposed. Comparison study of classical and hybrid exciter has been carried out. For the electromagnetic calculation two approaches have been applied: an analytical approach (based...
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Application of the Optimization Methods to the Search of Marine Propulsion Shafting Global Equilibrium in Running Condition
PublicationFull film hydrodynamic lubrication of marine propulsion shafting journal bearings in running condition is discussed. Considerable computational difficulties in non-linear determining the quasi-static equilibrium of the shafting are highlighted. The approach using two optimization methods (the particle swarm method and the interior point method) in combination with the specially developed relaxation technique is proposed to overcome...
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The influence of water and mineral oil on volumetric losses in a hydraulic motor
PublicationIn this paper volumetric losses in hydraulic motor supplied with water and mineral oil (two liquids having significantly different viscosity and lubricating properties) are described and comparison. The experimental tests were conducted using an innovative hydraulic satellite motor, that is dedicated to work with different liquid, including water. The sources of leaks in this motor are characterized and described also. On this...
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Analysis of the Accuracy of Pulse Estimation Using Smart Watches
PublicationThe purpose of this paper is to perform an analysis of the accuracy of the pulse estimation by comparing readings from a smartwatch with readings from medical devices. The study required writing applications that allow continuous pulse measurement. As a result, two applications were created for the smartwatch. The first one is dedicated to Android Wear devices, while the other one is compatible with Tizen watches. The next step...
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The selected roof covering technologies in the aspect of their life cycle costs
PublicationIn the article is presented an analysis of the life cycle costs calculation for selected roof coverings. The scope of research includes costs of construction, maintenance and demolition of the roof covering structure for two alternative technologies – the traditional and new generation. On the presented example of an industrial building with a roof area of 1000 m², the above costs are taken to consideration for the roof covering...
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Distribution of relaxation times as a method of separation and identification of complex processes measured by impedance spectroscopy
PublicationImpedance spectroscopy is one of the most commonly performed measurements to characterize electronic and electrochemical systems. Impedance spectra have limited resolution and many different processes may overlap what could be the reason of obstructions in its proper later analysis. Up to date, there are three approaches to solve this problem: examining impedance spectra itself, fitting spectra with equivalent circuits, and calculating...
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Utilization of fuzzy rules in computer character animation
PublicationThe chapter presents a method for automatic enhancement of computer character animation utilizing fuzzy inference. First the user designs a prototype version of animation, with keyframes only for important poses, roughly describing the action. Then animation is enriched with new motion phases calculated by the fuzzy inference system using descriptors given by the user. Various degrees of motion fluency and naturalness are possible...