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Search results for: PATH LOSS MODELLING
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Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
PublicationA voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology,...
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Modelling of joining route segments of differential curvature
PublicationThe paper presents a new general method of modelling route segments curvature using differential equations. The method enables joining of route segments of different curvature. Transitional curves of linear and nonlinear curvatures have been identified in the case of joining two circular arcs by S-shaped and C-oval transitions. The obtained S-shaped curves have been compared to the cubic C-Bezier curves and to the Pythagorean hodograph...
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Modelling, Simulation and Optimization of the Wavemaker in a Towing Tank
PublicationThe paper analyses the problem of experimental identification (frequency response), modelling and optimization of the towing tank wavemaker in the Scilab/Xcos environment. The experimental identification of the objects (the towing tank wavemaker placed in the hydrodynamic laboratory of the CTO S.A. Ship Design and Research Centre (CTO)) and the implementation of the models in the simulation environment, enable to perform: 1. tuning...
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Modelling of Nuclear Power Plant Steam Turbine
PublicationThe paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...
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Modelling of Nuclear Power Plant Steam Turbine
PublicationThe paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...
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Chapter 2: Modelling and analysis of rotor with magnetic bearing system
PublicationThe paper is concerned with rotor magnetic bearing system modelling. Such system is a relatively complex electromechanical system and can be considered as typical mechatronic one. The port-based modelling of physical systems has been used to obtain discrete-continuous model of considered system. Proposed approach enables to obtain reduced low-order lumped parameter representation of the system including gyroscopic interactions....
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The Influence of Selected Parameters of Numerical Modelling on Strains and Stresses at Weld Toe Notch
PublicationLatest development in the field of welding technology and prefabrication enabled massive production of thin-walled sandwich structures. Multi-layered sandwich structures are fabricated with the use of high-power CO2 lasers, friction welding, arc welding, hybrid welding, or other technique designed for the special purpose. Steel or aluminium alloy plates with thickness between 1 and 5 mm are connected by internal stiffeners. Strength...
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Mathematical and numerical modelling,W,IDE-EMSS,IIst,sem.01,lato,2023/24 (PG_00057379)
e-Learning CoursesModelling of controlled mechanical systems by the mixed method of rigid and flexible finite elements: The finite element volume problems. Dynamics of multibody systems. Modelling of stationary closed loop systems. Modelling of systems whose configuration changes with time. Modelling of nonlinear controlled systems. Optimal control at energy performance index: Control of continuous nonstationary systems in domain of generalised...
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Mathematical modelling of implant in an operated hernia for estimation of the repair persistence
PublicationThis paper presents mathematical modelling of an implanted surgical mesh used in the repair process of the abdominal hernia. The synthetic implant is simulated by a membrane structure. The author provides a material modelling of the implant based on the dense net model appropriate for technical fabrics. The accuracy of the proposed solution is evaluated by comparing the simulations of the dynamic behaviour of the system with the...
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COMBUSTION THEORY AND MODELLING
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Journal of Modelling in Management
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Journal of Choice Modelling
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Journal of Language Modelling
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Modelling, Measurement and Control A
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Mathematical Modelling and Control
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Infectious Disease Modelling
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Towards modelling of the environmental fate of pharmaceuticals using the QSPR-MM scheme
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Modelling of high frequency dynamic responses of engineering structures
PublicationModelling of high frequency dynamic responses of engineering structures, especially those related to wave propagation, is a real numerical challenge. Nowadays most of numerical models, used for that purpose, are based on the application of various finite element techniques. However, finite element discrete models may also be considered as possessing certain periodic structures, which may manifest themselves in particular scenarios....
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Conducted emi propagation modelling in the wound components.
PublicationThe modelling of EMC behaviour of power electronics converters require specific models of devices which are adequate in a wide frequency range. A novel equivalent-circuit model of the inductor, suitable for EMC applications, has been developed and validated. The model can be used for the analyses of wounded components' behaviour in the conducted-EMI frequency range. The parameters of the proposed model can be evaluated based on...
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Analytical method of modelling the geometric system of communication route
PublicationThe paper presents a new analytical approach to modelling the curvature of a communication route by making use of differential equations. The method makes it possible to identify both linear and nonlinear curvature. It enables us to join curves of the same or opposite signs of curvature. Solutions of problems for linear change of curvature and selected variants of nonlinear curvature in polynomial and trigonometric form were analyzed....
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Biological processes modelling for MBR systems: A review of the state-of-the-art focusing on SMP and EPS
PublicationA mathematical correlation between biomass kinetic and membrane fouling can improve the understanding and spread of Membrane Bioreactor (MBR) technology, especially in solving the membrane fouling issues. On this behalf, this paper, produced by the International Water Association (IWA) Task Group on Membrane modelling and control, reviews the current state-of-the-art regarding the modelling of kinetic processes of biomass, focusing on...
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Modelling method for a class of distributed-lumped parameter systems
PublicationThe paper presents an alternative approach for modelling and order reduction of continuous system. The proposed methodology combines application of two methods: the modal decomposition method and the rigid finite element method. The given continuous structure is divided into 1D continuous substructures. For each 1D substructure modal decomposition and reduction procedure is applied. Interactions between substructures are described...
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Respiratory system modelling and simulation basing on the forced oscilation technique
PublicationConventional methods of testing lung functioning demand a specific respiratory action of the patient. In contrast, the forced oscillation technique (fot) provides measurements obtained with a minimal cooperation of the subject. The aim of this study is to verify the usefulness of the forced oscillation technique modelling in respiratory system diagnosing. in order to do it two models of fot measurements have been considered: the...
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Modelling of acoustic backscattering by southern Baltic herring
PublicationAssessment of Baltic herring abundance can be carried out using acoustic techniques. Analysis of the relationship between the Baltic herring individual target strength, TS, and the total fish length, L, important for the acoustic assessment, showed the relationship to be dependent on the location of the study area. This finding motivated a detailed analysis of the relationship for the herring occurring in the southern Baltic...
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Hydrological predictors used for vegetation modelling in the lower Biebrza valley 1900-2099
Open Research DataThis data set contains hydrological predictors used for vegetation modelling in the lower Biebrza valley, NE Poland.The predictors were obtained from simulations using integrated hydrological model - HydroGeoSphere, with the Hydraulic Mixing-Cell method.Forcing data for the model were Twentieth Century Reanalysis (20CR) data for the period 1900-2015...
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Using FreeFEM open software for modelling the vibrations of piezoelectric devices
PublicationModelling vibrations of piezoelectric transducers has been a topic discussed in the literature for many decades. The first models - so-called one-dimensional - describe the vibrations only near operating frequency and near its harmonics. Attempts to introduce two-dimensional models were related to the possibility of one transducer working at several frequencies, including both thickness vibrations and those resulting from the transducer...
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Krzysztof Giaro prof. dr hab. inż.
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublicationA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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Modelling of performance of an AUV stealth vehicle. Design for operation.
PublicationIn the paper some results of research connected with modelling of performance and risk assessment of an AUV stealth vehicle are presented. A general approach to design of the stealth AUV autonomous underwater vehicle under consideration is introduced. The basic stealth characteristics of the AUV stealth vehicle are briefly described. The method of research is introduced. The AUV stealth vehicle concept is presented including the...
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Software tool for modelling of mechatronic systems with elastic continua
PublicationThe paper presents a systematic computational package for modelling and analysis of complex systems composed of multiple lumped and distributed parameter subsystems. The constructed computer program enables the frequency domain analysis of a class of linear systems and to obtain reduced order model in the form of bond graph. Obtained modal bond graph can be directly exported into 20-Sim package to further processing including nonlinear...
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Modelling of heat and mass transfer through wooden buildings
PublicationThe aim of this review paper is to examine the most recent available studies dealing with theoretical, numerical and experimental aspects related to modelling of heat and mass transfer through wooden buildings. The main thermophysical, mechanical and hygrometric properties of wood are firstly discussed. Then, the basic governing equations of heat and mass transfer phenomena are presented. A detailed description of the physical...
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GENERALISED HERSCHEL MODEL APPLIED TO BLOOD FLOW MODELLING
PublicationThis paper introduces a new rheological model of blood as a certain generalisation of the standard Herschel-Bulkley model. This model is a rheological constitutive equation and belongs to the group of the so-called generalised Newtonian fluids. Experimental data is compared with results, obtained from the new model, to demonstrate that it allows for the best agreement together with Luo-Kuang model. The new model may be easily implemented...
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A two dimensional approach for modelling of pennate muscle behaviour
PublicationThe purpose of this study was to elaborate a two-dimensional approach for unipennate and bipennate striated skeletal muscle modelling. Behavior of chosen flat pennate muscle is modelled as a rheological system composed of serially linked passive and active fragments having different mechanical properties. Each fragment is composed of three elements: mass element, elastic element and viscous element. Each active fragment furthermore...
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Cost‐efficient performance‐driven modelling of multi‐band antennas by variable‐fidelity electromagnetic simulations and customized space mapping
PublicationElectromagnetic (EM) simulations have become an indispensable tool in the design of contemporary antennas. EM‐driven tasks, for example, parametric optimization, entail considerable computational efforts, which may be reduced by employing surrogate models. Yet, data‐driven modelling of antenna characteristics is largely hindered by the curse of dimensionality. This may be addressed using the recently reported domain‐confinement...
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Modelling of dark fermentation of glucose and sour cabbage
PublicationIn the article, modified Anaerobic Digestion Models 1 (ADM-1) was tested for modelling dark fermentation for hydrogen production. The model refitting was done with the Euler method. The new model was based on sets of differential equations. The model was checked for hydrogen production from sour cabbage in batch and semi-batch in 5 g VSS (volatile solid suspension)/L and at the semi-batch process from glucose at 5 and 10 g VSS/L....
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A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
PublicationThe ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants...
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On various modelling approaches to real-time visualisation of blood flow
PublicationThis paper reviews various modelling approaches to real-time visualisation of blood flow. These include classic, macroscale approach based on the momentum conservation equation together with a proper constitutive equation. Moreover, modern micro- and mesoscale approaches, such as molecular dynamics and dissipative particle dynamics, are discussed. Advantages and disadvantages of the discussed methods are highlighted with particular...
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LLA : A New Anypath Routing Scheme Providing Long Path Lifetime in VANETs
PublicationVehicular ad-hoc networks (VANETs) are a promising solution to improve the road traffic safety, reduce the environmental pollution, or simply provide the on-board infotainment services. However, these actions are often not possible due to high mobility of vehicles causing frequent failures of VANET links. In this paper, we focus on anypath routing to improve the reliability of multihop VANET communications. In particular, the paper...
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From Emotional Intelligence to Self-Injuries: A Path Analysis in Adolescents With Conduct Disorder
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Choosing Exploration Process Path in Data Mining Processes for Complex Internet Objects
PublicationWe present an experimental case study of a novel and original framework for classifying aggregate objects, i.e. objects that consist of other objects. The features of the aggregated objects are converted into the features of aggregate ones, by use of aggregate functions. The choice of the functions, along with the specific method of classification can be automated by choosing of one of several process paths, and different paths...
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Choosing Exploration Process Path in Data Mining Processes for Complex Internet Objects
PublicationWe present an experimental case study of a novel and original framework for classifying aggregate objects, i.e. objects that consist of other objects. The features of the aggregated objects are converted into the features of aggregate ones, by use of aggregate functions. The choice of the functions, along with the specific method of classification can be automated by choosing of one of several process paths, and different paths...
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Empirical formulas for determination of the propagation loss in urban radio access links
PublicationOpisano wielowariantowy model empiryczny tłumienia propagacyjnego przeznaczonego do analizowaniai projektowania radiowych systemów dostępwych w warunkach zabudowy miejskiej, opracowanego na podstawie obszernych pomiarów tego tłumienia w rzeczywistych warunkach takiej zabudowy. Scharakteryzowano przydatność użytkową tego modelu.
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Impedance-based sensing of the interlayer adhesion loss in organic coating systems.
PublicationZmienne parametry środowiska takie jak: temperatura,wilgotność i promieniowanie UV powodują degradację własności ochronnych powłok organicznych. Stosując sensor w postaci elektrod wykonanych z prądoprzewodzącego tuszu umieszczonych pomiędzy warstwami zestawu oraz technikę spektroskopii impedancyjnej stwierdzono możliwość monitorowania utraty adhezji międzywarstwowej.
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Volume efficiency loss in axial pumps caused by working fluid compressibility.
PublicationPrzedstawiono teoretyczną analizę wpływu ściśliwości cieczy roboczej konstrukcji mechanizmu rozrządu pompy wielotłoczkowej osiowej na straty energetyczne w przestrzeni martwej. Podano wyniki uzyskane dla typowych konstrukcji.
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Impedance-based sensing of the interlayer adhesion loss in organic coating systems
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Sudden Hearing Loss Treated With Hyperbaric Oxygen (HBO) – Case Study
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Empirical Relationship Describing Total Convective and Radiative Heat Loss in Buildings
PublicationOn the basis of theoretical considerations of convective-radiative heat transfer, a relationship was developed enabling the total convective and radiative heat flux QC+R emitted from any object at tw and its surroundings at t∞ to be calculated from known values of the surface temperature of such an object, i.e., the known temperature difference Δt=tw - t∞ and average air temperature Tav. This relationship is applied to thermal...
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Volatility modelling and market risk analysis 2024/2025
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Relevance of Urban Freight Transport Modelling Towards the Challenges of Urban Freight Policy
PublicationThe main objective of this paper is to investigate how recent trends in urban freight transport analysis and modelling are related to urban freight measures set out in Gdynia’s 2016 Sustainable Urban Mobility Plan. Building on the literature a review framework was defined including 1) stakeholders, 2) descriptors, 3) objectives and 4) solution approach applied in freight modelling efforts. It was clear that the implementation...
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Simplified saturation modelling in three-leg power transformer for the system stability analisys
PublicationThe paper presents a simplified method for modelling non-linearity of the magnetic circuit of the power transformer. The saturation effect is implemented by describing the self and mutual inductances as a function of the magnetic flux. The most important element of this function is the saturation coefficient which is calculated based on transient state during the unloaded transformer switch on. The transformer model is described...