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Wyniki wyszukiwania dla: MEAN PATH LOSS
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An Approach to Mean Path Loss Model Estimation for Off-Body Channels
PublikacjaThis paper presents an approach to estimation of the mean path loss model parameters in off-body Body Area Networks channels. In this approach, the path loss exponent is constrained to a value obtained for the line-of-sight (LoS) propagation in the co-polarised channel, considering a generalised static scenario. The comparison of the goodness of fit between the proposed approach and other approaches, for a set of measurements obtained...
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublikacjaIn this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...
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Path Loss Modelling for Location Service Applications
PublikacjaThe aim of this paper is the path loss modeling for the radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the UMTS are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation of the distance between the mobile station (MS) and the base station (BS) is outlined. This...
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Propagation Path Loss Modeling in Container Terminal Environment
PublikacjaThis paper describes novel method of path loss modeling for radio communication channels in container port area. Multi-variate empirical model is presented, based on multidimensional regression analysis of real path loss measurements from container terminal environment. The measurement instruments used in propagation studies in port area are also described.
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Path Loss Modelling in the Untypical Outdoor Propagation Environments
PublikacjaIn the paper three ways of path loss modelling in the untypical outdoor environments are presented. The exemplary untypical outdoor environment is analyzed. The investigated environment is characterized, and the measurement campaign are shortly described. The following models have been analyzed: the COST231 Walfisch-Ikegami model, the modified COST231Walfisch-Ikegami model tuned on the basis of empirical data, and the empirical...
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Propagation Path Loss Modelling in Container Terminal Environment
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Measurements of Path Loss in Off-Body Channels in Indoor Environments
PublikacjaThis paper presents a measurements of the path loss for validation of a statistical model for off-body radio channels in an indoor multipath environment, which considers the distance dependent mean path loss, and describes body shadowing and fast fading components in a statistical way. The measurement equipment and propagation indoor environment have been presented. Two different bodies and five static and two walking scenarios...
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Path Loss Analysis in Off-Body Channels in Indoor Environment
PublikacjaThis temporary document describes an analysis of path loss in off-body channels in an indoor environment. The influence of body orientation and on-body antenna placement on path loss in off-body communications as well as of different bodies has been investigated. Five static scenarios, six distances between body and antenna and eight body orientations were analysed; moreover, two dynamic scenarios were investigated. The smallest...
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Measurements of Path Loss in Off-Body Channels in Indoor Environments
PublikacjaThe main goal of the paper is to investigate the influence of body orientation and on-body antenna placement on the path loss in off-body communications. In addition, the influence of different bodies is analysed.
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Path Loss Analysis for the IoT Applications in the Urban and Indoor Environments
PublikacjaThe Internet of Things (IoT) networks concept implies their presence in a various and untypical locations, usually with a disturbed radio signals propagation. In the presented paper an investigation of an additional path loss observed in an underground environment was described. The proposed measurement locations correspond to the operation areas of rapidly growing narrowband IoT (NBIoT) networks, the ones using the Long Term Evolution...
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Mean Crossover in evolutionary path planning method for maritime collision avoidance
PublikacjaAbstract: This paper presents the use of mean crossover genetic operator for path planning using evolutionary algorithm for collision avoidance on sea. Mean crossover ensures widening of the possible solutions' set that can be achieved in comparison to exchange crossover variant. The research shown, that the mean crossover allows to achieve results independent from the initial generation and quicker transition of thealgorithm from...
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Path Loss Measurements in Wideband Radio Link Designed for Maritime Environment
PublikacjaIn the article, the research and analysis of path loss in designed and evaluated digital radio link for high-speed data transmission in maritime environment is presented. Collected samples of received signal were used to determine the mean path loss and its standard deviation. Measuring campaign was carried out in a real maritime conditions. The mean value of path loss reached 126 dB on a distance of 11.16 km.
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Modification of Selected Propagation Models in Terms of Path Loss Estimation in Container Terminal
PublikacjaIt is particularly important to look for any propagation model that could be useful for designing mobile radio networks in container terminal environment. Selected propagation models have been investigated. Firstly - basing on measurements results - they have been evaluated in this scope and the analysis has shown, that the adjustment is needed. This modification improved significantly the accuracy of path loss modelling. For the...
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Performance Evaluation of GAM in Off-Body Path Loss Modelling for Body Area Networks
PublikacjaThis paper addresses the performance evaluation of an off-body path loss model, based on measurements at 2.45 GHz, which has been developed with the use of the Generalised Additive Model, allowing to model a non-linear dependence on different predictor variables. The model formulates path loss as a function of distance, antennas’ heights, antenna orientation angle and polarisation, results showing that performance is very sensitive...
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Radio Channel Measurements in 868 MHz Off-Body Communications in a Ferry Environment
PublikacjaIn this paper, a characterization of the 868 MHz off-body radio channel in BANs is presented. Measurements were carried out in a ferry environment using a specific set-up. A method for path loss using radio distance measurements (RDMs) was developed. It allows to automate the measurements process and make it independent from the variable speed of a moving person. Based on the observed path loss as a function of distance, the obtained...
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An Empirical Model for the Polarisation Characteristics of Indoor Off-Body Channels
PublikacjaThis paper presents an analysis of the polarisation characteristics for the channel in dynamic off-body communications, and an empirical channel model, based on measurements performed at 2.45 GHz in an office environment. Body presence and propagation conditions have a strong influence on signal depolarisation. The model assumes three components for the total path loss: mean path loss, represented by a log-distance function with...
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Fading Modelling in Dynamic Off-Body Channels
PublikacjaThis paper presents an off-body fading channel model for Body Area Networks (BANs) in indoor environments. The proposed model, which is based on both simulations and measurements in a realistic environment, consists of three components: mean path loss, body shadowing, and multipath fading. Seven scenarios in an indoor environment (a medium-size room with furniture, mostly consisting of wooden tables and chairs) have been measured:...
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An Off-Body Channel Model for Body Area Networks in Indoor Environments
PublikacjaThis paper presents an off-body channel model for body area networks (BANs) in indoor environments. The proposed model, which is based on both simulations and measurements in a realistic environment, consists of three components: mean path loss, body shadowing, and multipath fading. Seven scenarios in a realistic indoor office environment containing typical scatterers have been measured: five were static (three standing and two...
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Fading Modelling in Dynamic Off-Body Channels
PublikacjaThis paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components,...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Radio Channel Measurements in Body-to-Body Communications in Different Scenarios
PublikacjaThis paper presents body-to-body radio channel measurements at the 2.45 GHz band, for different body motion scenarios and on-body antenna placements, and both indoor and outdoor environments. Measurement equipment, investigated scenarios and considered environments are described, an initial analysis of results being presented. The mean path loss and the standard deviation depend on the mutual location of transmitting and receiving...
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Radio Channel Measurements in Off-Body Communications in a Ferry Passenger Cabin
PublikacjaThis paper presents an off-body radio channel measurements in a ferry passenger cabin at 2.45 GHz band, for static sleeping scenarios with different body orientation and on-body antennas placements, and also for upper and lower sleeping berths. The measurements have been performed with two types of on-body wearable receiving antennas: FlexPIFA (flexible planar inverted F antenna), and FlexNotch (flexible adhesive-backed notch antenna)...
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Rotor Blade Geometry Optimisation in Kaplan Turbine
PublikacjaThe paper presents the description of method and results of rotor blade shape optimisation. The rotor blading constitutes a part ofturbine flow path. Optimisation consists in selection of the shape that minimises ratio of polytrophic loss. Shape of the blade isdefined by the mean camber line and thickness of the airfoil. Thickness is distributed around the camber line based on the ratio ofdistribution. Global optimisation was done...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Influence of User Mobility and Antenna Placement on System Loss in B2B Networks
PublikacjaIn this paper, the influence of user mobility and on-body antenna placement on system loss in body-to-body communications in indoor and outdoor environments and different mobility scenarios is studied, based on system loss measurements at 2.45 GHz. The novelty of this work lies on the proposal of a classification model to characterise the effect of user mobility and path visibility on system loss, allowing to identify the best...
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System Loss in UWB Off-Body Communications in a Ferry Environment
PublikacjaIn this paper, the system loss in UWB off-body communications in a ferry environment based on measurements is presented. A mobile measurement set-up, consisting of WBAN nodes with UWB DWM1000 modules, was used. System loss was split into LOS and NLOS conditions. For the former, the smallest mean value, 24.4 dB, was obtained for the user approaching the fixed terminal, with the antenna on his chest, and the largest, 28.1 dB, for...
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Proposal of a System Loss Model for Body Area Network in Passenger Ferry Environment
PublikacjaIn the paper, proposal of an empirical off-body system loss model for Body Area Networks working in a passenger ferry environment at 2.45 GHz has been presented. The measurements were carried out for dynamic scenarios in the discotheque passenger ferry environment. The general model formula consists of three components: mean system loss, attenuation resulting from the variable antenna position on the human body, and attenuation...
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System Loss Model for Body-to-Body Networks in Indoor and Outdoor Environments
PublikacjaA system loss model for body-to-body networks in indoor and outdoor environments is proposed in this paper, based on measurements taken at 2.45 GHz. The influence of the type of environment, antenna visibility and user mobility on model parameters has been investigated. A significant impact of mutual antennas’ placement and their visibility is shown. The proposed model fits well to empirical data, with the average root mean square...
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Burst loss probability for the combination of extended offset time based service differentiation scheme and PPS in optical burst switching network
PublikacjaIn the paper analytical model for calculating burst loss probabilities for the combination of two service differentiation schemes for OBS network namely: extended offset time based scheme and PPS (Preemption Priority Schemes) is revised. Moreover authors introduce analytical model for calculating burst loss probabilities for an optical path when OBS network employs both service differentiation schemes and JET signaling. The comparison...
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An Empirical Propagation Model for Corridors in Office Buildings
PublikacjaThis paper presents an empirical propagation path loss model for corridors in office buildings. The proposed model estimates changeable character of radio signal attenuation, based on a special approach as a combination of the simple free-space model with the author’s model. The measurement stand and measurement scenario are described. The propagation path loss research have been made in corridor for different frequencies in range...
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Statistical Tuning of Walfisch-Ikegami Model for the Untypical Environment
PublikacjaThe Walfisch-Ikegami model has been investigated in terms of mobile radio systems designing in the untypical environment such as the maritime container terminal. The measurement equipment and procedures have been described as well as characteristics of investigated environment. Results of the statistical tuning in terms of path loss estimation in such environment have been analysed. The analysis has proved improvement of the path...
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Statistical Tuning of Walfisch-Ikegami Model for the Untypical Environment
PublikacjaThe Walfisch-Ikegami model has been investigated in terms of mobile radio systems designing in the untypical environment such as the maritime container terminal. The measurement equipment and procedures have been described as well as characteristics of investigated environment. Results of the statistical tuning in terms of path loss estimation in such environment have been analysed. The analysis has proved improvement of the path...
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System Loss Model for Body Area Networks in Room Scenarios
PublikacjaThis paper presents an analysis of system loss in Body Area Networks for room scenarios, based on a wideband measurement campaign at 5.8 GHz. The measurements were performed with a fixed antenna transmitting vertically and horizontally polarised signals, while the user wears dualpolarised antennas. The average system losses in co- and crosspolarised channels are 41.4 and 42.6 dB for vertically polarised transmitted signals and...
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Selected Propagation Models Modification for Application in Container Terminal
PublikacjaIt is particularly important to look for any propagation model that could be useful for designing mobile radio systems in container terminal environment. The selected propagation models have been investigated. The applied research methodology has been described too. Results of the statistical adjustment in terms of signal loss determination in such environment have been analysed. The analysis have proved effectiveness of adjustment...
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Empirical Adjustment of the Selected Propagation Models for Application in the Peculiar Environment of the Container Terminal
PublikacjaIt is important to look for any propagation model that could be useful for designing mobile radio systems in container terminal environment. Selected propagation models have been investigated. The applied research methodology has been described too. Results of the statistical adjustment in terms of signal loss determination in such environment have been analysed. The analysis has proved effectiveness of adjustment by increasing...
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Characteristics of Propagation Conditions in the Container Terminal Environment
PublikacjaIn the paper a characteristics of propagation conditions in the container terminal environment is presented. The investigated environment is characterized on the example of Gdansk Deepwater Container Terminal in Poland. An empirical propagation model for path loss calculation in mobile radio links in a container terminal environment is presented.
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Badania i analiza uwarunkowań propagacyjnych w środowisku uprzemysłowionym
PublikacjaGłówne osiągnięcia rozprawy: - wykonanie – zgodnie z wymaganiami normatywnymi zawartymi w zaleceniach ITU-R – nowatorskich badań tłumienia sygnału radiowego na terenie Głębokowodnego Terminalu Kontenerowego (ang. Deepwater Container Terminal - DCT) w Gdańsku i zebranie obszernego materiału pomiarowego, liczącego blisko 290 tysięcy przypadków propagacyjnych, - przeprowadzenie statystycznych badań przydatności wybranych znanych modeli...
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Efficiency of service recovery in scale-free optical networks under multiple node failures
PublikacjaIn this paper we examine the properties of scale-free networks in case of simultaneous failures of two networknodes. Survivability assumptions are as follows: end-to-end path protection with two node-disjoint backup pathsfor each working path. We investigate three models of scale-free networks generation: IG, PFP and BA.Simulations were to measure the lengths of active and backup paths and the values of service recovery time.We...
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Empirical Propagation Model for the Container Terminal Environment
PublikacjaIn the paper the empirical propagation model for mobile radio links in a container terminal environment is presented and the investigated environment Deepwater Container Terminal in Gdansk, Poland) is characterized. Described empirical model was elaborated on the basis of almost 290 thousand propagation path measurements in real conditions. The diversity of conditions occurring in different places of the container terminal has...
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Performance analysis of an rfid-based 3d indoor positioning system combining scene analysis and neural network methods
PublikacjaThe main purpose of this research is to improve localization accuracy of an active Radio Frequency Identification, RFID tag, in 3D indoor space. The paper presents a new RFID based 3D Indoor Positioning System which shows performance improvement. The proposed positioning system combines two methods: the Scene Analysis technique and Artificial Neural Network. The results of both simulation using Log-Distance Path Loss Model and...
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An Off-Body Narrowband and Ultra-Wide Band Channel Model for Body Area Networks in a Ferry Environment
PublikacjaIn the article an off-body narrowband and ultra-wide band channel model for Body Area Networks in a ferry environment is described. A mobile, heterogeneous measurement stand, that consists of three types of devices: miniaturized mobile nodes, stationary reference nodes and a data acquisition server was developed. A detailed analysis of both radio channels parameters in untypical indoor environment was carried out. An analysis of...
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An Off-Body Narrowband and Ultra-Wide Band Channel Model for Body Area Networks in a Ferryboat Environment
PublikacjaIn the article an off-body narrowband and ultra-wide band channel model for body area networks in a ferryboat environment is described. Considering the limited number of publications there is a need to develop an off-body channel model, which will facilitate the design of radio links, both from the multimedia services provider and the security point of view, for body area networks in this atypical environment. A mobile heterogeneous...
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Wideband Off-Body Channel Characteristics with Dynamic User
PublikacjaThis paper presents the preliminary results of a dynamic off-body channel characterisation study, based on wideband measurements at 5.8 GHz in an indoor environment. The Channel Impulse Response (CIR) was measured for a scenario with the user approaching and departing from the off-body antenna. A CIR deconvolution procedure was performed jointly in two polarisations, and the received signal power, Cross-Polarisation Discrimination...
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Minimal surfaces and conservation laws for bidimensional structures
PublikacjaWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
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Design of experiments approach for ultimate strength assessment of corroded stiffened plates
PublikacjaThe impact of corrosion degradation on the ultimate strength of stiffened plates subjected to compressive loading is investigated. The DoE technique is used considering different plate and column slenderness ratios and corrosion severity. The FE method, considering geometrical and material nonlinearities, is employed. A two-stage corrosion degradation model is adopted. Firstly, a uniform thickness loss is adopted to reflect the...
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Performance of ASON/GMPLS architecture in condition of wavelength conversion and without wavelength conversion
PublikacjaThe paper regards the problem of ASON/GMPLS performance in condition of wavelength and without wavelength conversion. The authors present influence analysis in condition of wavelength and non-wavelength conversion on the ASON/GMPLS control plane performance represented by mean Connection Set-up Time E (CST) and request loss probabilities. The offered traffic to the transport layer and request intensity have been changed for evaluation...
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Exergy and Energy Analyses of Microwave Dryer for Cantaloupe Slice and Prediction of Thermodynamic Parameters Using ANN and ANFIS Algorithms
PublikacjaThe study targeted towards drying of cantaloupe slices with various thicknesses in a microwave dryer. The experiments were carried out at three microwave powers of 180, 360, and 540 W and three thicknesses of 2, 4, and 6 mm for cantaloupe drying, and the weight variations were determined. Artificial neural networks (ANN) and adaptive neuro-fuzzy inference systems (ANFIS) were exploited to investigate energy and exergy indices of...
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Advances in Modelling and Analysis of Strength of Corroded Ship Structures
PublikacjaThe present study reviews the recent advances in modelling and analyses the strength of corroded ship structures. Firstly, the time-variant methodologies that consider only the mean structural element thickness loss due to corrosion degradation are identified. Corrosion degradation is regarded as the phenomenon that causes uneven thinning of specimens. This has been captured by various researchers as the loss of mechanical properties...
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Impact of Propeller Emergence on Hull, Propeller, Engine, and Fuel Consumption Performance in Regular Head Waves
PublikacjaIn this study, the impact of propeller emergence on the performance of a ship (speed), propeller (thrust, torque, and RPM), a diesel engine (torque and RPM) and fuel consumption are analysed under severe sea conditions. The goal is to describe the variation in the system variables and fuel consumption rather than analysing the motion of the ship or the phenomenon of propeller ventilation in itself. A mathematical model of the...