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DYNAMIC ANALYSIS OF HISTORIC RAILWAY BRIDGES IN POLAND IN THE CONTEXT OF ADJUSTING THEM TO PENDOLINO TRAINS
PublicationThe article presents the dynamic analysis of the historic railway bridge in Tczew as an example of the usefulness of such type of bridge for high-speed trains. The model of the bridge and the simulation of rolling stock passage was performed in SOFISTIK program. The scope of work includes experimental studies, the solution of the problem concerning the correct solution features dynamic model takes into account the dependencies...
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Effect of Soft Handover on the Capacity of WCMDA/FDD Interfece Using MRC RAKE Receiver in Uplink
PublicationIn the paper the mechanism of soft and hard hanover in UMTS is presented. Simulation tests for different services having various performance requirements and transmission rates have beeen made. Simulation results showing effect of soft handover in comparison with hard handover on the capacity of WCMDA/FDD radio interfaceare described, when the RAKE receiver with Maximal Ratio Combining has been implemented in RNC.
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Performance analysis of data transmission in MC-CDMA radio interface with turbo codes
PublicationMulti-carrier code division multiple access (MC-CDMA) technique is a combination of two radio access techniques: CDMA and orthogonal frequency division multiplexing and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface. It also presents encoders and decoders of turbo codes which were used in simulation of the MC-CDMA technique. Two turbo codes with 8-state...
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Control of nonlinear and linearized model of self-balancing electric motorcycle
PublicationSelf-Balancing Electric Motorcycle (SBEM) is a dynamic and nonlinear electro-mechanical system. In this paper, the process of mathematical modelling and line-arization of SBEM is presented. The model of the control system in Matlab envi-ronment is implemented. The control system using the PID controller is designed. The operation of particular structures of the PID controller on the simulation model is compared. Due to simulation...
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Soft – Partial Frequency Reuse Method for LTE-A
PublicationIn the paper a novel SPFR frequency reuse method is proposed which can be used for improvement of physical resources utilization efficiency in LTE-A. The proposed method combines both SFR and PFR giving the possibility of more flexible use of frequency band in different regions of a cell. First, a short study on the problem of frequency reuse in cells is discussed including bibliography overview....
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Shallow Water Communication with an Object Buried in Bottom Sediments
PublicationUnderwater acoustic communications (UAC) in shallow water applications is a very difficult task. This task becomes even more difficult when there is a need to ensure reliable communication with an object buried in bottom sediments. The article presents a simulation of an acoustic transmission channel in conditions of strong multi-path propagation to an object buried in bottom sediments. The impulse response method was used, supported...
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Modelling of the High Speed Multi-Pole Synchronous Generator for Application in More Electric Aircraft Power Systems
PublicationIn this paper different models of the synchronous generator are presented. The simulation results compared with the measurements are shown. Certain physical phenomena are included in described models for the porpoise of adequate analysis of the more electric aircraft power system. For different modelling levels, such as functional level or behavioural level, different physical phenomena have been included. Simulation results for...
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Autonomous Driver Based on an Intelligent System of Decision-Making
PublicationThe paper presents and discusses a system (xDriver) which uses an Intelligent System of Decision-making (ISD) for the task of car driving. The principal subject is the implementation, simulation and testing of the ISD system described earlier in our publications for the task of autonomous driving. The design of the whole ISD system is a result of a thorough modelling of human psychology based on an extensive literature study. Concepts...
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Wideband Signal Generation for Jamming Radio-Controlled Improvised Explosive Devices
PublicationThis paper focuses on modelling operation of a wideband jamming signal generator, considering the effects present in real device which influence the shape of transmitted signal’s spectrum. Introduction is followed by a brief overview of AEGIS project, aim of which is to develop a mobile generator of electromagnetic curtain. Next, simulation model is described which includes the factors...
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Hyperbolic position location estimation in the multipath propagation environment
PublicationThe efficiency analysis a hyperbolic position location estimation in the multipath propagation environment in the wideband code division multiple access (WCDMA) interface was presented. Four, the most popular methods: Chan's, Foy's, Fang's and Friedlander's were considered. These algorithms enable the calculation of the geographical position of a mobile station (MS) using the time differences of arrival (TDOA) between several base...
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Evaluation of the fast impedance spectroscopy method in the laboratory measurement system
PublicationIn this paper the method for fast impedancespectroscopy of technical objects with very high impedance(|Zx| ≥ 1 GΩ) is evaluated by means of simulation and practicalexperiment. The method is based on excitation of an object, witha square pulse and measurements of voltage and currentresponses with DAQ card. The object impedance spectrum isobtained with use of continuous Fourier transform. Someimprovements of the method concerned...
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Modeling energy consumption of parallel applications
PublicationThe paper presents modeling and simulation of energy consumption of two types of parallel applications: geometric Single Program Multiple Data (SPMD) and divide-and-conquer (DAC). Simulation is performed in a new MERPSYS environment. Model of an application uses the Java language with extension representing message exchange between processes working in parallel. Simulation is performed by running threads representing distinct process...
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Analysis of economical lighting of highways in the environment of SMOL language
PublicationThe paper puts forward and implements a method of designing and creating a modelling simulation environment for eztensive and complete analysis of economical lighting on highways. From a general design viewpoint, the proposed solution explores the concept of a network description language (SMOL), which has been designed to describe the necessary network functions, mechanisms, and devices; for the purpose of their computer simulation...
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How much a geometrical model of a honeycomb seal can be simpli ed in the CFD calculation
PublicationThis paper presents the inuence of geometry simplication on the results obtained in the computational fluid dynamics simulation. The subject of simulation was part of the honeycomb seal located at the inlet to high pressure part of a steam turbine. There were three different geometrical models assumed in the calculations. First one was two-dimensional case and two others were three dimensional, one with the radius of curvature...
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The forming and emission of high power electromagnetic pulses
PublicationAn impulse energy source, a power conditioning system and an electromagnetic field emitter are essential to generate an electromagnetic field pulse (EMFP) with a specific frequency bandwidth. Selected simulation results for a power conditioning system consisting of a fuse opening switch and a paraboloidal electromagnetic emitter have been presented in this article. The synthetic system examined in the simulation is powered by an...
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Numerical Determination of the Load-Bearing Capacity of a Perforated Thin-Walled Beam in a Structural System with a Steel Grating
PublicationThis article presents the results of numerical simulations of a structural system consisting of steel perforated thin-walled beams and a steel grating. The simulations were conducted using the finite element method. The analysis took into account physical and geometric nonlinearity as well as the contact between the steel grating and the beams. The main goal of the research was to develop load-bearing curves for the main beam in...
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Hybrid DUMBRA: an efficient QoS routing algorithm for networks with DiffServ architecture
PublicationDynamic routing is very important issue of current packet networks. It may support the QoS and help utilize available network resources. Unfortunately current routing mechanisms are not sufficient to fully support QoS. Although many research has been done in this area no generic QoS routing algorithm has been proposed that could be used across all network structures. Existing QoS routing algorithms are either dedicated to limited...
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Analysis of electromagnetic disturbances in DC network of grid connected building-integrated photovoltaic system
PublicationThis paper focuses on conducted electromagnetic interference (EMI) emissions and propagation in the DC network of grid connected building integrated photovoltaic (PV) system. The investigated PV system, consists of ten solar panels, cabling and the grid-connected one phase inverter. The EMI simulation model of the real PV system has been developed with the aid of impedance analyzer measurements of solar panels and the DC network...
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A Multi-Fidelity Surrogate-Model-Assisted Evolutionary Algorithm for Computationally Expensive Optimization Problems
PublicationIntegrating data-driven surrogate models and simulation models of different accuracies (or fideli-ties) in a single algorithm to address computationally expensive global optimization problems has recently attracted considerable attention. However, handling discrepancies between simulation models with multiple fidelities in global optimization is a major challenge. To address it, the two major contributions of this paper include:...
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Simulating Malware with MAlSim
PublicationThis paper describes MAlSim - Mobile Agent Malware Simulator - a mobile agent framework developed to address one of the most important problems related to the simulation of attacks against information systems i.e. the lack of adequate tools for reproducing behaviour of malicious software (malware). The framework can be deployed over the network of an arbitrary information system and it aims at simulating behaviour of each instance...
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Simulating malware with MAlSim
PublicationThis paper describes MAlSim - Mobile Agent Malware Simulator - a mobile agent framework developed to address one of the most important problems related to the simulation of attacks against information systems, i.e. the lack of adequate tools for reproducing behaviour of malicious software (malware). The framework can be deployed over the network of an arbitrary information system and it aims at simulating behaviour of each instance...
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading,...
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Modeling Parallel Applications in the MERPSYS Environment
PublicationThe chapter presents how to model parallel computational applications for which simulation of execution in a large-scale parallel or distributed environment is performed within the MERPSYS environment. Specifically, it is shown what approaches can be adopted to model key paradigms often used for parallel applications: master-slave, geometric parallelism (single program multiple data), pipelined and divide-and-conquer applications....
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The forming and emission of high power electromagnetic pulses
PublicationAn impulse energy source, a power conditioning system and an electromagnetic field emitter are essential to generate an electromagnetic field pulse (EMFP) with a specific frequency bandwidth. Selected simulation results for a power conditioning system consisting of a fuse opening switch and a paraboloidal electromagnetic emitter have been presented in this article. The synthetic system examined in the simulation is powered by...
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Low harmonic multipulse voltage converters using coupled reactors
PublicationThis paper presents a novel approach to the multi pulse voltage converters (VC), especially voltage source inverters (VSI) and matrix converters (MC) based on several typical identical modules connected in parallel using coupled reactors. Such arrangements resulting in lower voltage distortions at extremely low switching frequency. The proposed arrangement was validated by simulation. Laboratory models of 18- and 24pulse 3-level...
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Generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statku
PublicationOmówiono automatyczne generowanie modeli symulacyjnych na potrzeby systemu ekspertowego wspomagającego projektowanie układów automatyki statków. Na podstawie przyjętych założeń projektowych system ekspertowy zleca badania wybranych struktur podsystemów elektroenergetycznych statków. Aplikacja symulacyjna pobiera z biblioteki modele matematyczne elementów składowych struktur, a następnie zestawia modele symulacyjne, wykonuje badania...
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Dynamic Positioning System with Vectorial Backstepping Controller
PublicationThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. Some parameters of observer were optimized off-line...
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Design of battery charging system update for glider launcher
PublicationThis paper presents an innovative solution for increasing life of lead-acid batteries used in a glider launcher. The study is focused on upgrading a charging system instead of a costly full replacement of it. Based on literature review, the advanced three-stage charging profile was indicated. The new topology of the power converter was proposed and a simulation model was developed. A simulation study was performed which leads to...
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Resonance problems in UHV transmission lines
PublicationThe paper presents resonance phenomena observed in 400 kV transmission lines in the Polish power system. Two events are analysed, when shunt reactors used for reactive power compensation, caused overvoltages and overcurrent protection tripping as a result of resonance. An oscillographic fault recordings from protection devices are compared to time domain simulation results. The obtained simulation results match fault recordings,...
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Effect of Pin Shape on Thermal History of Aluminum-Steel Friction Stir Welded Joint: Computational Fluid Dynamic Modeling and Validation
PublicationThis article studied the effects of pin angle on heat generation and temperature distribution during friction stir welding (FSW) of AA1100 aluminum alloy and St-14 low carbon steel. A validated computational fluid dynamics (CFD) model was implemented to simulate the FSW process. Scanning electron microscopy (SEM) was employed in order to investigate internal materials’ flow. Simulation results revealed that the mechanical work...
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Economics of credit scoring management
PublicationCredit scoring models constitute an inevitable element of modern risk and profitability management in retail financial lending institutions. Quality,or separation power of a credit scoring model is usually assessed with the Gini coefficient. Generally, the higher Gini coefficient the better, as in this way a bank can increase number of good customers and/or reject more bad applicants. In...
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Modeling of a Quasi-Resonant DC Link Inverter Dedicated to Common-Mode Voltage and Ground Current Reduction
PublicationIn this paper, the modeling methodology of the AC drive system with a Parallel Quasi-Resonant DC Link Inverter (PQRDCLI) is described. A presented modeling approach is an attractive tool used for the effective evaluation of a common-mode (CM) voltage and grounds current reduction methods. Designed models of inverter, induction machine (IM), and cable are simple, thus the methods for parameter extraction are not complicated. Verification...
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Experiments with the Universal Constructor in the DigiHive Environment
PublicationThe paper discusses the performance and limitations of the universal constructor embedded in the DigiHive environment and presents the result of two simulation experiments showing the possibility of workaround the limitations.
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Dynamiczna aplikacja Internetowa ASP.NET silnika indukcyjnego jako elementu wirtualnego laboratorium maszyn elektrycznych
PublicationTematem referatu jest dynamiczna aplikacja internetowa, która umożliwia symulację obwodową silnika indukcyjnego trójfazowego Sg 100 L2 z wykorzystaniem interfejsu przeglądarki WWW. Model matematyczny silnika jest zdefiniowany w tzw. osiach naturalnych i sformułowany na podstawie metody energetycznej Lagrange’a. Do implementacji modelu maszyny w aplikacji internetowej wybrano projekt typu Web Forms, który jest składnikiem środowiska...
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Ocena zastosowania wybranych reguł wymiany narzędzi w systemie produkcyjnym
PublicationIn this paper, an integrated analytical and simulation modelling framework has been developed with the objective to explore total system planning and operational issues. It enables in particular structuring the alternative process flow in manufacturing systems and their extended investigation under different tool exchange rules with limited number of tool inventory. Simulation studies performed with the proposed rules in the environment...
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Efficiency of the Use of LTE System Radio Resources in Highway Transport Enironment
PublicationThe paper describes the problem of analysis of throughput-coverage characteristics of the LTE system. Simulation results of the efficiency of the use of LTE radio resources are presented. Simulation studies on the basis of original model of the LTE network simulator were carried out. In addition, the evaluation of throughput for a single connection, and available capacity were evaluated in the context of the use of the same...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublicationThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
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Hybrid Expert System for Computer-Aided Design of Ship Thruster Subsystems
PublicationThe article presents an expert system supporting the design of ship's power subsystems, in particular the thruster subsystem. The proposed hybrid expert system uses the results of simulation tests as the additional source of knowledge. The results of system operation are collated in a report which can be used as part of ship design description. The work oriented on developing the expert system is the continuation of the research...
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Damage detection in turbine wind blades by vibration based methods
PublicationThe paper describes results of numerical simulation for damage localization in the composite coat of a wind turbine blade usingmodal parameters and a modern damage detection method (wavelet transform).
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Hybrid Finite Element Method Development for Offshore Structures’ Calculation with the Implementation of Industry Standards
PublicationIn the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulationand evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modelingand solution rely on finite element methods and cover the simulation of the structure’s properties along with the influenceof the marine environment – sea currents, wave...
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Kompleksowa analiza symulacyjna układu napędowego zespołu trakcyjnego
PublicationThe paper describes an approach to comprehensive analysis of traction electric drive. The drivetrain of ED-74 electric unit equipped with four inverter-fed induction motors was modeled in Matlab/Simulink. The model consists of functional blocks as: motors, inverters, drive controllers, filters. Structure and operation of the model was described. Chosen simulation results were presented and discussed. Two methods of modeling the...
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Numerical analysis of the ostiomeatal complex aeration using the CFD method
PublicationWe aimed to analyse ostiomeatal complex (OMC) aeration using the computational fluid dynamics (CFD) method of simulation based on human craniofacial computed tomography (CT) scans. The analysis was based on CT images of 2 patients: one with normal nose anatomy and one with nasal septal deviation (NSD). The Reynolds-Average Simulation approach and turbulence model based on linear eddy viscosity supplemented with the two-equation...
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Photovoltaic Maximum Power Point Technique based on Incremental Conductance (INCON) control algorithm
PublicationMaximum output power status can significantly improve the deployment rate of solar energy system. In order to get the maximum power output, issue of tracking maximum power point (MPP), reduced harmonics around MPP and improve efficiency of the solar power energy system, this paper presents the improved maximum power point tracking (MPPT) control...
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Resonant DC link inverters for AC motor drive systems – critical evaluation
PublicationIn this survey paper, resonant and quasiresonant DC link inverters are reexamined for AC motor drive applications. Critical evaluation of representative topologies is based on simulation and waveform analysis to characterize current/voltage stress of components, control timing constraints and feasibility. A special concern over inverter common-mode voltage and voltage gradient du/dt limitation capacity is discussed for motor bearing...
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Initial Report on Numerical Modeling of Blood Flow in Myocardial Bridge Region of Coronary Artery: Concept of Model Validation
PublicationThe paper presents a numerical method of blood flow simulation within the coronary artery covered by the myocardial bridge. The myocardial bridge is a congenital coronary abnormality caused by the blood vessel location under one of the heart muscles. In this case, the blood flow within the vessel is partially disturbed which can cause several consequences. The presented numerical simulation allowed us to estimate the blood flow...
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COMPARISON OF NOISE EMISSION OF HCT AND CLASSIC VEHICLE COMBINATIONS FOR TIMBER TRANSPORTATION IN SWEDEN
PublicationBy means of a special simulation tool, the noise emission of a high-capacity heavy vehicle (11 axles) was compared to that of a classic heavy vehicle (a truck-dolly-semitrailer with 8 axles). The two cases are designated “Extended vehicle” versus “Classic vehicle” in this study, having total lengths of 34 and 25 m, respectively. The Classic vehicle represents the most common articulated heavy vehicle configuration for transport...
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Comprehensive comparison of compact UWB antenna performance by means of multi-objective optimization
PublicationAn optimization-based procedure for comprehensive performance comparison of alternative compact UWB antenna topologies is discussed. The assessment of the antenna performance is conducted with respect to the structure size and its reflection response. More specifically, the best possible tradeoffs between these two figures of merit are identified through multiobjective optimization at the level...
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Modification of the Reloading Plastic Modulus in Generalized Plasticity Models for Soil by Introducing a New Equation for the Memory Parameter in Cyclic Loadings
PublicationNowadays, with the widespread supply of very powerful laboratory and computer equipment, it is expected that the analyses conducted for geotechnical problems are carried out with very high precision. Precise analyses lead to better knowledge of structures’ behavior, which, in turn, reduces the costs related to uncertainty of materials’ behavior. A precise analysis necessitates a precise knowledge and definition of the behavior...
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Research Platform for Monitoring, Control and Security of Critical Infrastructure Systems
PublicationSustainable operation of Critical Infrastructure Systems (CISs) is of a major concern to modern societies. Monitoring, control and security of such systems plays a key role in guaranteeing continuous, reliable and above all secure access to the resources provided by these systems. Development of adequate software and hardware structures, as well as algorithms to perform such functions cannot be done apart from the operational conditions...