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Wyniki wyszukiwania dla: model tests
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Nonlinear dynamic analysis of the pure “buckling” mechanism during blow-out trauma of the human orbit
PublikacjaConsidering the interplay between orbital bones and intraorbital soft tissues, commonly accepted patterns of the blow-out type of trauma within the human orbit require more thorough investigation to assess the minimal health-threatening impact value. Two different three-dimensional finite element method (FEM) models of the human orbital region were developed to simulate the pure “buckling” mechanism of orbital wall fracture in...
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The Analysis of Overall Ship Fuel Consumption in Acceleration Manoeuvre using Hull-Propeller-Engine Interaction Principles and Governor Features
PublikacjaThe problem of reduction of greenhouse gas emissions in shipping is currently addressed by many research works and related industries. There are many existing and visionary technologies and ideas, which are conceptually defined or practically realised. This goal can be achieved in different ways, and reducing fuel consumption is one of the major methods. In these circumstances, the aim of this study is to analyse the possibility...
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Adjusting the Stiffness of Supports during Milling of a Large-Size Workpiece Using the Salp Swarm Algorithm
PublikacjaThis paper concerns the problem of vibration reduction during milling. For this purpose, it is proposed that the standard supports of the workpiece be replaced with adjustable stiffness supports. This affects the modal parameters of the whole system, i.e., object and its supports, which is essential from the point of view of the relative tool–workpiece vibrations. To reduce the vibration level during milling, it is necessary to...
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New concept of drilling auger for displacement pile installation
PublikacjaIn 2020, a new version of the screw displacement auger for pile installation in soil was developed and patented in Poland. It was named DPDT (Displacement Pile Drilling Tool). The general aim of its development was to reduce the soil resistances to the auger during screwing into the ground while maintaning a good load-bearing capacity for the screw displacement piles. The “DPDT-Auger” prototype was tested as a scaled-down model...
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Buckling resistance of a metal column in a corrugated sheet silo - experiments and non-linear stability calculations
PublikacjaThe results of experimental and numerical tests of a single corrugated sheet silo column’s buckling resistance are presented in this study. The experiments were performed in a real silo with and without bulk solid (wheat). A very positive impact of the bulk solid on the column buckling resistance occurred. The experimental results were first compared to the buckling resistance calculated by Eurocode 3 formulae. The comparison revealed that...
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Novel hierarchical nonlinear control algorithm to improve dissolved oxygen control in biological WWTP
PublikacjaWastewater treatment is a problem known to humankind for centuries. The quality of treated sewage determines the condition of reservoirs around the world. Control of such a complex and nonlinear system as a wastewater treatment plant requires thorough knowledge of the process. The paper presents a hierarchical control system of a Sequencing Batch Reactor (SBR) in Wastewater Treatment Plant (WWTP) taking into account a model based...
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Automatic music signal mixing system based on one-dimensional Wave-U-Net autoencoders
PublikacjaThe purpose of this paper is to show a music mixing system that is capable of automatically mixing separate raw recordings with good quality regardless of the music genre. This work recalls selected methods for automatic audio mixing first. Then, a novel deep model based on one-dimensional Wave-U-Net autoencoders is proposed for automatic music mixing. The model is trained on a custom-prepared database. Mixes created using the...
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Performance of the domestic micro ORC equipped with the shell-and-tube condenser with minichannels
PublikacjaIn this paper, the original compact shell-and-tube heat exchanger with circular minichannels of in-house design and manufacturing is presented as the condenser for the domestic micro heat and power plant investigations as well as other future technical applications. The heat exchanger is equipped with turbulizing baffles inside the shell. The shell itself is made of a tubular sleeve having an inner diameter of 0.067 m and the length...
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Towards Understanding of Mechanics of Hernia Managed by Synthetic Mesh in Laparoscopic Operation: A Single Case Study
PublikacjaIn this paper a research towards understanding of mechanics of ventral hernia operated with the use of Physiomesh Open image in new window implant and SecureStrap Open image in new window staples is described. Experimental and numerical studies are conducted for that purpose. Experimental works cover uni-axial tension tests of the implant samples and of the implant-staples-tissue system. Also experiments on implant-staples-tissue...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublikacjaThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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Prediction of maximum tensile stress in plain-weave composite laminates with interacting holes via stacked machine learning algorithms: A comparative study
PublikacjaPlain weave composite is a long-lasting type of fabric composite that is stable enough when being handled. Open-hole composites have been widely used in industry, though they have weak structural performance and complex design processes. An extensive number of material/geometry parameters have been utilized for designing these composites, thereby an efficient computational tool is essential for that purpose. Different Machine Learning...
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<title>Synchronous optical transmission data link integrated with FPGA for TESLA FEL SIMCON system: long data vector optical transceiver module tests</title>
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Properties comparison of rubber and three layer PTFE-NBR-bronze water lubricated bearings with lubricating grooves along full bush circumference based on experimental tests
PublikacjaWater lubricated bearings have been in industrial use for well over a century. During the last decade their traditional range has been expanded with new, modern products. Despite that fact, certain solutions continue to employ the standard rubber bearing with lubricating grooves located along entire bush circumference. The work presents experimental research conducted on comparable sliding bearings with lubrication grooves along...
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Bridge Non-Destructive Measurements Using a Laser Scanning during Acceptance Testing: Case Study
PublikacjaOwing to the recent proliferation of inventory works on roads and railways, bridge acceptance tests have increased exponentially. These tests’ results are often misinterpreted owing to the use of various measuring equipment types, rendering integrated interpretation problematic. It is also problematic that adjusting the measurement method is difficult when the structure’s response to load is uncertain. Therefore, it is important...
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The Influence of Cooperation on the Operation of an MPC Controller Pair in a Nuclear Power Plant Turbine Generator Set
PublikacjaThe paper discusses the problem of cooperation between multiple model predictive control (MPC) systems. This approach aims at improving the control quality in electrical energy generation and forms the next step in a series of publications by the authors focusing on the optimization and control of electric power systems. Cooperation and cooperative object concepts in relation to a multi MPC system are defined and a cooperative control...
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Shallow Water Experiment of OFDM Underwater Acoustic Communications
PublikacjaThe large variability of communication properties of underwater acoustic channels, and especially the strongly varying instantaneous conditions in shallow waters, is a challenge for the designers of underwater acoustic communication (UAC) systems. The use of phase modulated signals does not allow reliable data transmission through such a tough communication channel. However, orthogonal frequency-division multiplexing (OFDM), being...
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Equivalent Single Layer Models in Free Vibration Analysis of Laminated Multi-Layered Plates
PublikacjaThe performance of selected equivalent single-layer (ESL) models is evaluated within several classical benchmark tests for small amplitude free vibration analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation (FOSD) theory with some modifications incorporated including a correction of the transverse shear stiffness and an application of zigzag type functions....
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The home-made in situ passive flux sampler for the measurement of monoterpene emission flux: preliminary studies
PublikacjaThe paper presents the construction and metrological characteristics of the home-made in situ passive flux sampler, an analytical tool representing small-scale emission chambers working in situ and passively sampling analytes from the gaseous phase. The sorption element was a cylindrical container made of stainless steel net, packed with a carbon sorbent bed-graphitized charcoal, Carbograph 4 (35/50mesh). The recommended working/exposure...
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Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs
PublikacjaNowadays, the use of mathematical models and computer simulation allow analysis of many different technological solutions as well as testing various scenarios in a short time and at low financial budget in order to simulate the scenario under typical conditions for the real system and help to find the best solution in design or operation process. The aim of the study was to evaluate different concepts of biochemical processes and...
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Comparative Study of Balancing SRT by Using Modified ASM2d in Control and Operation Strategy at Full-Scale WWTP
PublikacjaDetailed knowledge on the composition of the influent going into the wastewater treatment system is essential for the development of a reliable computer model. In the context of WWTPs (wastewater treatment plants), the wastewater characteristics are not only important for activated sludge system modelling, but also have an impact on the appropriate control of single unit operations. The aim of this study was to evaluate the concepts...
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Adaptive Algorithm of a Tap-Changer Controller of the Power Transformer Supplying the Radial Network Reducing the Risk of Voltage Collapse
Publikacjahe development of renewable energy, including wind farms, photovoltaic farms as well as prosumer installations, and the development of electromobility pose new challenges for network operators. The results of these changes are, among others, the change of network load profiles and load flows determining greater volatility of voltages. Most of the proposed solutions do not assume a change of the transformer regulator algorithm....
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Modelowanie dynamiki odbieraka prądu pojazdu kolejowego do celów diagnostycznych
PublikacjaNiewłaściwa współpraca odbieraka prądu i sieci trakcyjnej, w trudnych warunkach lokalnych, może prowadzić do uszkodzenia sieci trakcyjnej i pantografu. W ramach rozwoju metod monitoringu i diagnostyki dla tych podsystemów, tworzone są nowe i dokładniejsze narzędzia symulacyjne, których zakres obejmuje modelowanie zarówno napowietrznej sieci trakcyjnej i pantografu, a także ich dynamicznego oddziaływania. Głównym celem jest dokładniejsza...
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Respiration rate estimation for model predictive control of dissolved oxygen in wastewater treatment plant
PublikacjaRespiration rate is very important parameter for biological processes in wastewater treatment plant (WWTP). The sequential algorithm for estimate the respiration rate is proposed and investigated. The Kalman filter (KF) is used. Simulation tests for the benchmark WWTP are presented.Respiracja jest bardzo ważnym parametrem dla prawidłowego przebiegu procesów biologicznych w oczyszczalni ścieków. W artykule przedstawiono i zbadano...
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Edgewise Compressive Behavior of Composite Structural Insulated Panels with Magnesium Oxide Board Facings
PublikacjaEdgewise compression response of a composite structural insulated panel (CSIP) with magnesium oxide board facings was investigated. The discussed CSIP is a novel multifunctional sandwich panel introduced to the housing industry as a part of the wall, floor, and roof assemblies. The study aims to propose a computational tool for reliable prediction of failure modes of CSIPs subjected to concentric and eccentric axial loads. An advanced...
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Evaluation and behaviour of slowly biodegradable substrate on mathematical modelling of oxygen uptake rate in activated sludge systems
PublikacjaThe effect of the readily biodegradable (Ss) fraction in activated sludge systems has been extensively investigated, but only minor information can be found about the effect of Xs on OUR in activated sludge systems. The aim of this study was to determine the evaluation and behaviour of Xs on mathematical modelling of OUR using ASM2d and its modification. The essential study was divided into two major parts: experimental investigation...
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Fractographical quantitative analysis of EN-AW 2024 aluminum alloy after creep pre-strain and LCF loading
PublikacjaThis paper explores the applicability of a new damage parameter combining both fracture surface topography and loading features to estimate the fatigue lifetime under creep pre-strain and low-cycle fatigue loading. Fractures of EN-AW 2024 aluminum alloy caused by mixed creep and low-cycle fatigue loading are experimentally characterized and quantified via surface topography analysis. The specimens were preliminary damaged in a...
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Modelling and Control of a Brushless Multiphase Doubly-Fed Induction Generator in a Stand-Alone Wind Generation System
PublikacjaThe development of the novel multiphase brushless doubly-fed generator system and voltage controller for stand-alone mode configuration is proposed in this paper. The generator system is based on the new machine construction with multiphase control winding and traditional three-phase power winding. The dynamic model of multiphase brushless doubly-fed generator is presented, and the control strategy for voltage amplitude and frequency...
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Application of Galvanostatic Non-Linear Impedance Spectroscopy to the Analysis of Metallic Material Degradation
PublikacjaThis study presents a novel application of Non-Linear Electrochemical Impedance Spectroscopy (NLEIS) in galvanostatic mode for the rapid, non-destructive assessment of metal degradation. By using galvanostatic mode instead of traditional potentiostatic methods, polarization-related challenges are mitigated, enabling more accurate and reliable analysis. The technique allows for the determination of corrosion rates (corrosion current)...
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CFD analysis of fluid flow through the labyrinth seal
PublikacjaSteam and gas turbines are some of the fundamental means of power generation. The energy efficiency of the turbines, however, is not satisfactory. Ever since the start-up of the first turbine in the world, engineers have been striving for their increased efficiency. Multiple solutions to the problem of steam loss in an operating turbine are available. The use of seals is one of them. Empirical methods or numerical calculations...
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Celowe zanieczyszczanie pilotów w łączu w górę w interfejsie 5G NR
PublikacjaReferat poświęcono zagadnieniu zakłócania sygnałów pilotowych w interfejsie radiowym 5G NR. Przedstawiono charakterystykę sygnału referencyjnego DMRS oraz uwarunkowania możliwości jego selektywnego zakłócenia. Opisano schemat transmisji w kanale fizycznym PUSCH, zaimplementowany w oprogramowaniu Sionna. Zaprezen-towano model symulacyjny oraz założenia badań wpływu zanieczyszczenia pilotów na jakość transmisji. Przedsta-wiono wyniki...
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Physical and mathematical modelling of implant-fascia system in order to improve laparoscopic repair of ventral hernia
PublikacjaThis paper describes an investigation of biomechanical behaviour of hernia repair, which is focused on the selection of safe linking of certain type of implant with fascia in laparoscopic operation. The strength of various fixations of the implant to the fascia is analysed. Methods: The research is based on experimental observations of operated hernia model behaviour during a dynamic impulse load corresponding to post-operative...
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Mixed integer nonlinear optimization of biological processes in wastewater sequencing batch reactor
PublikacjaWastewater treatment plays a key role for humanity. The waste entering lakes, rivers, and seas deteriorates daily quality of life. Therefore, it is very important to improve the efficiency of wastewater treatment. From a control point of view, a biological wastewater treatment plant is a complex, non-linear, multidimensional, hybrid control system. The paper presents the design of the optimizing hierarchical control system applied...
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Wiktoria Wojnicz dr hab. inż.
OsobyDSc in Mechanics (in the field of Biomechanics) - Lodz Univeristy of Technology, 2019 PhD in Mechanics (in the field of Biomechanics) - Lodz Univeristy of Technology, 2009 (with distinction) Publikacje z listy MNiSW (2009 - ) Wojnicz W., Wittbrodt E., Analysis of muscles' behaviour. Part I. The computational model of muscle. Acta of Bioengineering and Biomechanics, Vol. 11, No.4, 2009, p. 15-21 Wojnicz W., Wittbrodt E., Analysis...
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Analiza drgań przewodu jezdnego sieci trakcyjnej w aspekcie oceny jej stanu technicznego.
PublikacjaGórna sieć trakcyjna jest nadal najefektywniejszym sposobem zasilania kolejowych pojazdów elektrycznych. Sieć jezdna nie ma możliwości technicznych redundancji, co wymaga okresowej oceny stanu technicznego w celu zapewnienia prawidłowej współpracy z odbierakami prądu pojazdów. W artykule przedstawiono aspekty oceny stanu technicznego górnej sieci trakcyjnej na podstawie modelowania matematycznego i wybranych badań laboratoryjnych....
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Wybrane aspekty modelowania matematycznego kolejowego odbieraka prądu
PublikacjaNieprawidłowa współpraca odbieraka z siecią jezdną, w niekorzystnych warunkach lokalnych, prowadzi do uszkodzeń sieci lub odbieraka. Może być to spowodowane niewłaściwym wykonaniem lub utrzymaniem tych istotnych elementów układu zasilania. Tego typu sytuacje awaryjne powodują duże opóźnienia w ruchu pociągów i generują olbrzymie koszty. Wskazuje to na duże znaczenie odpowiednich rozwiązań konstrukcyjnych sieci i odbieraków oraz...
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Database for integration of information in distributed data exchange system elements of Border Guard
PublikacjaThe paper presents the database solution for integration of information in distributed data exchange system elements of the Polish Border Guard. The proposed database solution is described in the context of data exchange system elements which control position and store identification data of vessels (fishing, sports and sailing boats) and other suspicious objects on the territorial sea, sea-coast and the internal sea-waters controlled...
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Influence of Installation Effects on Pile Bearing Capacity in Cohesive Soils – Large Deformation Analysis Via Finite Element Method
PublikacjaIn this paper, the whole process of pile construction and performance during loading is modelled via large deformation finite element methods such as Coupled Eulerian Lagrangian (CEL) and Updated Lagrangian (UL). Numerical study consists of installation process, consolidation phase and following pile static load test (SLT). The Poznań site is chosen as the reference location for the numerical analysis, where series of pile SLTs...
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Equivalent single-layer models in deformation analysis of laminated multilayered plates
PublikacjaThe performance of selected Equivalent Single-Layer (ESL) models is evaluated within several classical benchmark tests for linear static analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation theory (FOSD) with some modifications incorporated including a correction of the transverse shear stiffness and an application of zig-zag type functions. Seven...
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Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine
PublikacjaA small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performancehas been investigated numerically. Results of a parametric study have been presented in this paper.As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected.Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT).Simulations were carried out with Computational Fluids...
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Modeling of luminance distribution in CAVE-type virtual reality systems
PublikacjaAt present, one of the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems are usually consisted of four, five or six projection screens and in case of six screens arranged in form of a cube. Providing the user with a high level of immersion feeling in such systems is largely dependent of optical properties of the system. The modeling of physical phenomena plays nowadays...
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Modification and Optimization of the United-Residue (UNRES) Potential Energy Function for Canonical Simulations. I. Temperature Dependence of the Effective Energy Function and Tests of the Optimization Method with Single Training Proteins
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Blowing Kinetics, Pressure Resistance, Thermal Stability, and Relaxation of the Amorphous Phase of the PET Container in the SBM Process with Hot and Cold Mold. Part II: Statistical Analysis and Interpretation of Tests
PublikacjaThe technology of filling drinks without preservatives (such as fresh juices, iced tea drinks, and vitaminized drinks) is carried out using hot filling. Mainly due to the production costs and lower carbon footprint, polyethylene terephthalate (PET) bottles are increasingly used in this technology. In this paper, the main aim is to describe and interpret the results of statistical analysis of the influence of the temperature of...
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How personality traits, sports anxiety, and general imagery could influence the physiological response measured by SCL to imagined situations in sports?
Dane BadawczeThe data were collected to understand how individual differences in personality (e.g. neuroticism), general imagery, and situational sports anxiety are linked to arousal measuring with skin conductance level (SCL) in situational imagery (as scripted for sport-related scenes). Thirty persons participated in the study, aged between 14 and 42 years, with...
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Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublikacjaIn this study, dedicated methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
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Znaczenie płci w procesie zakupu marek własnych sieci handlowych – analiza wielogrupowa
PublikacjaThe purpose of the article is to analyze the differences in the behavior of men and women in the process of purchasing store brands (SBs). Using an established conceptual model, we intended to identify differences, depending on gender of buyers, in the size of the effects of store image and brand price-image on perceived risk and subsequently on store brand purchase intention. A total of 652 respondents participated in the study....
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Z type Observer Backstepping For Induction Machines
PublikacjaThis paper contains a relatively new synthesis method for non-linear objects, named backstepping. This method can be used to obtain the observer structure. The paper presents the structure of the speed observer which is a new proposition of observer backstepping with additional state variables marked Z. The rotor speed can be estimated in three different ways. The first is based on the adaptive approach, the second on the nonadaptive...
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Optimization of the spindle speed during milling of large-sized structures with the use of technique of Experiment-Aided Virtual Prototyping
PublikacjaIn the paper are presented considerations concerning vibration suppression problems during milling of large-sized workpieces with the use of innovative method of matching the spindle speed of cutting tool. It depends on repeatable change of the spindle speed value as soon as the optimal vibration state of the workpiece approaches. The values of dominant “peaks” in the frequency spectra and the Root Mean Square (RMS) values of time...
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Enhancing women’s engagement in economic activities through information and communication technology deployment: evidence from Central–Eastern European countries
PublikacjaThis study takes a macro perspective to examine the associations between the economic deployment of information and communication technology (ICT), women’s labor market participation, and economic growth in Central–Eastern European countries between 1990 and 2017. We use data extracted from World Bank Development Indicators, World Development Reports, and the World Telecommunication/ICT Indicators Database. Our methodological framework...
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Parameters’ Identification of Perzyna and Chaboche Viscoplastic Models for Aluminum Alloy at Temperature of 120◦C
PublikacjaThe main purpose of this paper is the parameters identification of the Perzyna and the Chaboche models for the aluminum alloy at elevated temperature. The additional purpose is comparison of the results for these viscoplastic models. The results have been verified by the numerical simulation of the laboratory tests. The material parameters have been calculated on the basis of the uniaxial tension test. The determination of the...
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Design of a test bench for determining the general characteristics of an internal combustion engine using a hydraulic power take-off system
PublikacjaThe paper presents a design of an engine test bench, which is used to determine the general characteristics of a truck engine using a power take-off (PTO). PTO drives a hydraulic system that generates a load on the engine at various points in its operation in the power range specified by the hydraulic system. The design allows for stationary and mobile tests with the test bench mounted on the truck, without any modification of...