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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Effect of Flow Normalization in Micro-Pin-Finned Heat Sink: Numerical Study
PublicationThe micro-pin-fin heat sink (MPFHS) is widely employed for the heat transfer enhancement of microchannel heat sinks. In the current paper, the effect of flow normalization on the thermohydraulic performance of micro-pin-finned heat sinks is studied numerically. Two geometries of MPFHSs, the conventional design micro-pin-fin heat sink (CD-MPFHS) with a uniform-width micro pin fin and the proposed design micro-pin-fin heat sink (PD-MPFHS)...
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Integration, Processing and Dissemination of LiDAR Data in a 3D Web-GIS
PublicationThe rapid increase in applications of Light Detection and Ranging (LiDAR) scanners, followed by the development of various methods that are dedicated for survey data processing, visualization, and dissemination constituted the need of new open standards for storage and online distribution of collected three-dimensional data. However, over a decade of research in the area has resulted in a number of incompatible solutions that offer...
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Propagation of Acoustic Disturbances in Shallow Sea
PublicationPropagation of acoustic waves in shallow sea differs fundamentally from the same phenomenon occurring in deep sea in view of non-negligible distance from the sea bottom in the first case, where presence of two regions limiting the water layer results in the acoustic pressure distribution induced by a harmonic source has an interferential nature as a result of multi-path propagation of the acoustic signal. These interferential properties...
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Robust Object Detection with Multi-input Multi-output Faster R-CNN
PublicationRecent years have seen impressive progress in visual recognition on many benchmarks, however, generalization to the out-of-distribution setting remains a significant challenge. A state-of-the-art method for robust visual recognition is model ensembling. However, recently it was shown that similarly competitive results could be achieved with a much smaller cost, by using multi-input multi-output architecture (MIMO). In this work,...
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Robust Object Detection with Multi-input Multi-output Faster R-CNN
PublicationRecent years have seen impressive progress in visual recognition on many benchmarks, however, generalization to the out-of-distribution setting remains a significant challenge. A state-of-the-art method for robust visual recognition is model ensembling. However, recently it was shown that similarly competitive results could be achieved with a much smaller cost, by using multi-input multi-output architecture (MIMO). In this work,...
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Velocity Field Characteristics at the Inlet to a Pipe Culvert
PublicationA poorly designed culvert inlet structure causes scouring, which can lead to the collapse of the culvert and significant damage to the neighboring land. A set of laboratory tests was evaluated to examine velocity distribution at the culvert inlet. A three-dimensional acoustic Doppler velocimeterwas used to measure instantaneous flowvelocity upstream of the culvert. The analysis of mean velocities, turbulence strength, and Reynolds...
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Experimental tests of reinforced concrete deep-beams
PublicationThe paper presents results of experimental research of the reinforced concrete deep beam with a spatial arrangement. Tested structural elements consist of the cantilever deep beam loaded on the height and transverse deep beam with hanging on it another one. The analysis includes crack morphology, effort of steel and load distribution. The article verified effectiveness of two different kind of reinforcement in both tested deep...
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Application of Intuitionistic Fuzzy Sets to the assessment of technical university students
PublicationThe article proposes application of artificial intelligence methods to assess students of technical universities. The level of achieved educational goals can be assessed using measurements based on the idea of Fuzzy Intuitionistic Sets (IFS). A classification algorithm was developed and an exemplary distribution of the criteria values using IFS was presented. The application of the proposed approach in online education can enrich...
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Badanie dynamiki platform pływających morskich turbin wiatrowych z zastosowaniem metod numerycznej mechaniki płynów
PublicationPraca dotyczy badania ruchu platform pływających pod morskie turbiny wiatrowe. Przedstawiono w niej główne metody obliczeń i przedyskutowano ich zastosowanie. Na przykładzie koncepcji konstrukcji 3-kolumnowej platformy typu Spar przedstawiono metodykę wykonywania obliczeń z zastosowaniem programu AQWA opartego na metodzie dyfrakcyjnej, rozszerzonego o współczynniki wynikające z lepkości wyznaczone za pomocą obliczeń RANSE-CFD....
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Mobile devices and computing cloud resources allocation for interactive applications
PublicationUsing mobile devices such as smartphones or iPads for various interactive applications is currently very common. In the case of complex applications, e.g. chess games, the capabilities of these devices are insufficient to run the application in real time. One of the solutions is to use cloud computing. However, there is an optimization problem of mobile device and cloud resources allocation. An iterative heuristic algorithm for...
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Accuracy analysis of 3D model obtained by photogrammetric method on the example of historic room from Wisłoujście Fortress
PublicationThe article presents a comparison of obtained models of a test object. Close range photogrammetry was used to obtain 3D models. As test object was used one of the rooms located in Wisłoujście Fortress in Gdańsk, Poland. Different models were obtained by using different distribution and number of reference points. Article contains analysis of differences between coordinates of control points obtained from total station measurements...
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New Approach to Noncasual Identification of Nonstationary Stochastic FIR Systems Subject to Both Smooth and Abrupt Parameter Changes
PublicationIn this technical note, we consider the problem of finite-interval parameter smoothing for a class of nonstationary linear stochastic systems subject to both smooth and abrupt parameter changes. The proposed parallel estimation scheme combines the estimates yielded by several exponentially weighted basis function algorithms. The resulting smoother automatically adjusts its smoothing bandwidth to the type and rate of nonstationarity...
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Zastosowanie odcinków nieliniowej krzywizny w torze zwrotnym rozjazdu kolejowego
PublicationW pracy została przedstawiona analityczna metoda kształtowania toru zwrotnego rozjazdu kolejowego posiadającego na swojej długości odcinki nieliniowej krzywizny. Odcinki te służą łagodzeniu wykresu krzywizny w skrajnych strefach rozjazdu W omawianej metodzie dokonano identyfikacji problemu rozkładu krzywizny za pomocą równań różniczkowych. Uzyskane rozwiązania mają charakter uniwersalny; m. in. pozwalają na przyjmowanie dowolnych...
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Application of passive sampling techniques as a usable tool in the field of environmental quality monitoring
PublicationAnalysis of literature data published for the past 20 years leads to the conclusion, that passive sampling technique has been developing very quickly and is commonly used in the field of monitoring pollutants in air, water and soil environment. The popularity of application of passive sampling techniques in analytical and environmental chemistry results from its many advantages e.g.: Simplicity in use, low costs of exploitation,...
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Effective method for determining environmental loads on supporting structures for offshore wind turbines
PublicationThis paper presents a description of an effective method for determining loads due to waves, current and wind acting on the supporting structures of the offshore wind turbines. This method is dedicated to the structures consisting of the cylindrical or conical elements as well as (truncates) pyramids of polygon with a large number of sides (8 or more). The presented computational method is based on the Morison equation, which was...
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Probabilistic Approach to Precipitation-Runoff Relation in a Mountain Catchment: A Case Study of the Kłodzka Valley in Poland
PublicationOn the basis of daily precipitation and discharges recorded in 1974–2013 relations between precipitation and runoff in the Kłodzka Valley (KV) in south-western Poland were analyzed. The degree of synchronicity between them was determined using the bivariate Archimedean copulas. This study aims at identifying and then describe in a probabilistic way the precipitation and runoff relations in the area playing an important role...
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Effective method for determining environmental loads on supporting structures for offshore wind turbines
PublicationThis paper presents a description of an effective method for determining loads due to waves and current acting on the supporting structures of the offshore wind turbines. This method is dedicated to the structures consisting of the cylindrical or conical elements as well as (truncates) pyramids of polygon with a large number of sides (8 or more). The presented computational method is based on the Morison equation, which was originally...
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Geminate-pair dissociation yield in systems with exponential energetic disorder — A Monte Carlo study
PublicationGeminate electron–hole recombination in systems with exponential energetic disorder is studied by Monte Carlo method. The field and temperature dependencies of geminate-pair dissociation probability are calculated. It is established that the dissociation yield of carrier pairs depends mainly on the extent of carrier thermalization, which influences the Einstein relationship. The approximate limiting temperature is given by Te =...
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Volumetric incorporation of NV diamond emitters in nanostructured F2 glass magneto-optical fiber probes
PublicationIntegration of optically-active diamond particles with glass fibers is a powerful method of scaling diamond's magnetic sensing functionality. We propose a novel approach for the integration of diamond particles containing nitrogen-vacancy centers directly into the fiber core. The core is fabricated by stacking the preform from 790 soft glass canes, drawn from a single rod dip-coated with submicron diamond particles suspended in...
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Experimental investigations on the mechanical properties and damage detection of carbon nanotubes modified crumb rubber concrete
PublicationThis study presents a modified crumb rubber (MCR) concrete design mix reinforced with multi-walled carbon nanotubes (MWCNTs), mechanical characterization, and cracking monitoring using the acoustic emission (AE) technique. The results showed that the bridging effect of MWCNTs and MCR in the concrete mix mitigated the shortcomings of MWCNT-MCR concrete and improved the flexural and compressive strengths by 18.3% and 26.5%, respectively,...
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Comparison of various flow maldistribution quantification methods in mini heat exchangers
PublicationThe aim of study is to compare various flow maldistribution quantification methods, using velocity, mass flow rate, pressure, and temperature. An experimentally validated numerical study has been prepared and a heat exchanger with 34 semi-circular channels with a diameter of 3.1 mm has been tested. The minichannels were heated from the bottom with a heat flux of 50, 60, 70, and 80 kW/m2. The cases for various inlet velocities of...
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On cooperative image denoising
PublicationIn this paper we suggest how several competing image denoising algorithms, differing in design parameters, or even in design principles, can be combined together to yield a better and more reliable denoising algorithm. The proposed fusion mechanism allows one to combine practically all kinds of noise reduction tools. It also allows one to account for the distribution of measurement noise, and in particular - to cope with heavy-tailed...
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Stochastic equivalence scales in log-normal distributions of expenditures
PublicationIn the paper, the properties of the stochastic equivalence scales (SES) are analysed when expenditure distributions are log-normal. The SES provides the equivalent distribution of expenditures when the population of households is heterogeneous with respect to such attributes as household size, demographic cpmposition, etc. For log-normal expenditure distributions, the non-parametric SES deflators are proportional to the ration...
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Improvement of radiotracers experiments in mass transfer processes
PublicationThe greatest part of industrial mass transfer is based on continuous transportation of different substances throughout especially constructed installations. In that kind of practice, a flow of such mass in each part determines the process unit and can be described by the residence time distribution (RTD) of the substance inside this unit. This parameter may be evaluated by the properly arranged tracer experiment. It is worthwhile...
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On Nonlinear Dynamic Theory of Thin Plates with Surface Stresses
PublicationWe discuss the modelling of dynamics of thin plates considering surface stresses according to Gurtin–Murdoch surface elasticity. Taking into account the surface mass density we derive the two-dimensional (2D) equations of motion. For the reduction of the three-dimensional (3D) motion equations to the 2D ones we use the trough-the-thickness integration procedure. As a result, the 2D dynamic parameters of the plate depend not only...
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Experimental and numerical study on deformed steel columns subjected to impact load during earthquakes
PublicationThe soft-storey failure is one of the most typical types of damage observed in buildings during earthquakes. The failure of an upper soft storey of a structure results in large impact load acting on the lower floors and if the resistance of the structural members of the lower storeys is not sufficient it may further lead to progressive collapse of the whole building. The aim of the present paper is to investigate the dynamic behaviour...
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Modes of Failure Analysis in Reinforced Concrete Beam Using Laser Scanning and Synchro-Photogrammetry
PublicationThe following paper reveal the limitations and possibilities of terrestrial laser scanning technology adaptation in diagnostics of reinforced concrete beams. In this paper, authors present potential spectrum of TLS use in modes of failure analysis of R-C beams and determines under which conditions the laser technologies might be applied. Research was carried out at the Regional Laboratory of Structural Engineering at Gdansk University...
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Evaluation of polycaprolactone as a new sorbent coating for determination of polar organic compounds in water samples using membrane–SPME
PublicationCommercially available solid-phase microextraction fibers used for isolation of polar analytes are based on the adsorption phenomenon. In consequence, typical limitations bonded with analytes displacement and matrix effects are very frequent. In the present study, alternative solution is described. Polycaprolactone (PCL) was used for the first time as sorbent to isolate polar organic compounds from water samples using the membrane–solid-phase...
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Modes of Failure Analysis in Reinforced Concrete Beam Using Laser Scanning and Synchro-Photogrammetry - How to apply optical technologies in the diagnosis of reinforced concrete elements?
PublicationThe following paper reveal the limitations and possibilities of terrestrial laser scanning technology adaptation in diagnostics of reinforced concrete beams. In this paper, authors present potential spectrum of TLS use in modes of failure analysis of R-C beams and determines under which conditions the laser technologies might be applied. Research was carried out at the Regional Laboratory of Structural Engineering at Gdansk University...
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Enhancing rheological muscle models with stochastic processes
PublicationPurpose: Biological musculoskeletal systems operate under variable conditions. Muscle stiffness, activation signals, and loads change during each movement. The presence of noise and different harmonic components in force production significantly influences the behaviour of the muscular system. Therefore, it is essential to consider these factors in numerical simulations. Methods: This study aims to develop a rheological mathematical...
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Losses and energy efficiency of drive motors and systems
PublicationLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
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Influence of Material Thickness on the Ductile Fracture of Steel Plates for Shipbuilding
PublicationIn the shipbuilding industry, the risk of brittle fractures is relatively high because some units operate in arctic or subarcticzones and use high thickness (up to 100 mm) steel plates in their structures. This risk is limited by employing certifiedmaterials with a specific impact strength, determined using the Charpy method (for a given design temperature) and byexercising control over the welding processes (technology qualification,...
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Implementation of Hermite-Ritz method and Navier’s Technique for Vibration of Functionally Graded Porous Nanobeam Embedded in Winkler-Pasternak Elastic Foundation Using bi-Helmholtz type of nonlocal elasticity
PublicationPresent study is devoted to investigating the vibration characteristics of Functionally Graded (FG) porous nanobeam embedded in an elastic substrate of Winkler-Pasternak type. Classical beam theory (CBT) or Euler-Bernoulli beam theory (EBT) has been incorporated to address the displacement of the FG nanobeam. Bi-Helmholtz type of nonlocal elasticity is being used to capture the small scale effect of the FG nanobeam. Further, the...
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Study of Non-Newtonian biomagnetic blood flow in a stenosed bifurcated artery having elastic walls
PublicationFluid structure interaction (FSI) gained attention of researchers and scientist due to its applications in science felds like biomedical engineering, mechanical engineering etc. One of the major application in FSI is to study elastic wall behavior of stenotic arteries. In this paper we discussed an incompressible Non-Newtonian blood fow analysis in an elastic bifurcated artery. A magnetic feld is applied along x direction. For...
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Losses and energy efficiency of drive motors and systems
PublicationLosses and energy efficiency of every drive motor must be presented as functions of physical quantities independent of losses in the motor. Such quantities are speed and load required by the machine or device driven by the motor, changing in the drive operating field. Speed and load of the motor decide of the instantaneous useful power of the motor and also in a differentiated way of kinds and values of losses occurring in the...
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Temperature influences on shear stability of a nanosize plate with piezoelectricity effect
PublicationPurpose The purpose of this paper is to predict the mechanical behavior of a piezoelectric nanoplate under shear stability by taking electric voltage into account in thermal environment. Design/methodology/approach Simplified first-order shear deformation theory has been used as a displacement field. Modified couple stress theory has been applied for considering small-size effects. An analytical solution has been taken into account...
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Processing of point cloud data retrieved from terrestrial laser scanning for structural modeling by Finite Element Method
PublicationFinite Element Method is one most popular contemporary method of strength analysis. The method is an advanced method for solving differential equations, based on discretization, which means that area is divided into finite elements. Each finite element has a solution of the equation approximated by specific functions and performing the actual calculations only for nodes of this division. Finite Element Method is widely used in...
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Modeling of wood frame structures with different insulation materials under damaging dynamic loading
PublicationWood frame buildings are very popular in regions that are exposed to different dynamic excitations, such as damaging earthquakes. Their seismic resistance is really important in order to prevent structural damages and human losses. This paper presents the results of advanced numerical investigation carried out using the FEM. Based on the models of wall panels, the numerical model of real structure of the wood frame building has...
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The experimental identification of the dynamic coefficients of two hydrodynamic journal bearings operating at constant rotational speed and under nonlinear conditions.
PublicationHydrodynamic bearings are commonly used in ship propulsion systems. Typically, they are calculated using numerical or experimental methods. This paper presents an experimental study through which it has been possible to estimate 24 dynamic coefficients of two hydrodynamic slide bearings operating under nonlinear conditions. During the investigation, bearing mass coefficients are identified by means of a newly developed algorithm....
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ECONOMIC MEASURES AGAINST A PANDEMICS
PublicationThe appropriate level of treatment during periods of increasing workload in the health care system or a particular hospital is ensured either by changing the organization of the system and the principles of use of resources such as space, staff and consumables or their redistribution, or by financial resources such resources are increased or replenished. This article contributes to improve the concept of resource allocation as...
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THE ROLE OF THE STATE IN TAXATION. POLISH TAX POLICY AFTER 2015
PublicationThis article is an attempt to present and evaluate tax policy Polish of the years 2015-2020, i.e. the period which resulted in formulating the new government. These time was a period of tax reforms, the introduction of new taxes and public tributes, as well as new mechanisms to control tax collection. Moreover, the policies introduced also concern changes in the level of fiscalism and tax redistribution. The research methods adopted...
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No-local-broadcasting theorem for multipartite quantum correlations
PublicationWe prove that the correlations present in a multipartite quantum state have an operational quantum character even if the state is unentangled, as long as it does not simply encode a multipartite classical probability distribution. Said quantumness is revealed by the new task of local broadcasting, i.e., of locally sharing preestablished correlations, which is feasible if and only if correlations are stricly classical. Our operational...
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A Method for Optimising the Blade Profile in Kaplan Turbine
PublicationThis paper introduces a method of blade profile optimisation for Kaplan-type turbines, based on modelling the interaction between rotor and stator blades. Rotor and stator blade geometry is described mathematically by means of a midline curve and thickness distribution. Genetic algorithms are then used to find a global optimum that minimises the loss coefficient. This allows for variety of possible blade shapes and configurations....
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System of wireless magnetic sensors for detection and identification of ferromagnetic vehicles
PublicationThe paper presents the results of deformation of the Earth's magnetic field by land vehicles. Basing on the analysis of the shape of the magnetic field deformation, it is possible to detect and identify a vehicle. In order to eliminate the interference of the Earth's magnetic field by the environment, the measurements were performed in a differential configuration. Under a development project a wireless system of magnetic sensors...
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Effect of geometric imperfections on aluminium silo capacities
PublicationAn aluminum silo with initial imperfections is analysed. Two types of imperfections are considered. The first one takes the form of local indentations in the shell; their size and range are adopted on the basis of the standard guidelines. The second type is a global imperfection described through the use of its eigenforms and by means of two-dimensional random fields. The calculations are limited to two cases of loading: negative...
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Integrable zero-range potentials in a plane
PublicationWe examine general statements in the Wronskian representation of Darboux transformations for plane zero-range potentials. Such expressions naturally contain scattering problem solution. We also apply Abel theorem to Wronskians for differential equations and link it to chain equations for Darboux transforms to fix conditions for further development of the underlying distribution concept. Moutard transformations give a convenient...
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Research on the wear evenness of the tool in flat lapping
PublicationIn this paper, the dimensionless distribution of the material removal stock and the trajectories of abrasive grains cutting in single-sided lapping process are presented. They were numerically simulated based on the tribological model and kinematics equations. It can be observed that the trajectories geometry of single abrasive as well the velocities have a great influence on the final geometrical deviation. During machining, the...
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Reliability of production machines in the bakery industry – theoretical and practical issues
PublicationThe aim of the article is to present probabilistic models, which were then used to analyze the reliability of production machines in the baking industry. The author conducted research in the period from January 2, 2016 to December 31, 2018 regarding the measurement of reliability of a traditional production system based on a probabilistic concept. Due to the limited scope of the article, reliability calculations for a set of thermo-oil...
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Modern Arrangement for Reduction of Voltage Perturbations
PublicationThe contents of this chapter encompass general problems and the most important issues of power-supply-quality improvement in AC systems. In the context of the above, consideration is given to evaluation of bilateral interactions of receivers with an electrical power-distribution system and methods of their reduction. Also are discussed the basis of operation of the most important compensation-filtration devices and their applications...