Search results for: SCATTERING-DIRECTIONALITY SWITCHING
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Development of Intelligent Control for Annealing Unit to Ensure the Minimization of Retroactive Effects on the Supply Network
PublicationResearch conducted by our team focused on the development of a complete annealing unit, using modern technologies and components, such as a programmable logic controller, an industrial computer and microcontrollers, ensuring an intelligent way to control power semiconductor elements (SSR relays), with regard to minimizing retroactive effects on the supply network. This modern configuration offers a number of new possibilities of...
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Advanced Control Structures of Turbo Generator System of Nuclear Power Plant
PublicationIn the paper a synthesis of advanced control structures of turbine and synchronous generator for nuclear power plant working under changing operating conditions (supplied power level) is presented. It is based on the nonlinear models of the steam turbine and synchronous generator cooperating with the power system. Considered control structure consists of multi-regional fuzzy control systems with local linear controllers, including...
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The passive operating mode of the linear optical gesture sensor
PublicationThe study evaluates the influence of natural light conditions on the effectiveness of the linear optical gesture sensor, working in the presence of ambient light only (passive mode). The orientations of the device in reference to the light source were modified in order to verify the sensitivity of the sensor. A criterion for the differentiation between two states - "possible gesture" and "no gesture" - was proposed. Additionally,...
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Geometric analogue of holographic reduced representation
PublicationHolographic reduced representations (HRRs) are distributed representations of cognitive structuresbased on superpositions of convolution-bound n-tuples. Restricting HRRs to n-tuples consisting of 1,one reinterprets the variable binding as a representation of the additive group of binary n-tupleswith addition modulo 2. Since convolutions are not defined for vectors, the HRRs cannot be directlyassociated with geometric structures....
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Mitigating Traffic Remapping Attacks in Autonomous Multi-hop Wireless Networks
PublicationMultihop wireless networks with autonomous nodes are susceptible to selfish traffic remapping attacks (TRAs). Nodes launching TRAs leverage the underlying channel access function to receive an unduly high Quality of Service (QoS) for packet flows traversing source-to-destination routes. TRAs are easy to execute, impossible to prevent, difficult to detect, and harmful to the QoS of honest nodes. Recognizing the need for providing...
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Failure analysis of a high-speed induction machine driven by a SiC-inverter and operating on a common shaft with a high-speed generator
PublicationDue to ongoing research work, a prototype test rig for testing high-speed motors/generators has been developed. Its design is quite unique as the two high- speed machines share a single shaft with no support bearings between them. A very high maximum operating speed, up to 80,000 rpm, was required. Because of the need to minimise vibration during operation at very high rotational speeds, rolling bearings were used. To eliminate...
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Performance Evaluation of a Multidomain IMS/NGN Network Including Service and Transport Stratum
PublicationThe Next Generation Network (NGN) architecture was proposed for delivering various multimedia services with guaranteed quality. For this reason, the elements of the IP Multimedia Subsystem (IMS) concept (an important part of 4G/5G/6G mobile networks) are used in its service stratum. This paper presents comprehensive research on how the parameters of an IMS/NGN network and traffic sources influence mean Call Set-up Delay (E(CSD))...
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Sustainable investing exchange-traded funds: US and European market
PublicationThe key aim of the paper is to examine the diffusion of the sustainable investing exchange-traded funds (ETFs) on the European and US ETFs markets, with the special focus on the market shares of sustainable investing and conventional funds. The model of diffusion of innovation (logistic growth model) is applied. Monthly data on the assets of ETFs in the time period of 2006-2017 are used. Increasing assets of sustainable investing...
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Zastosowanie trendów przełącznikowych w analizie płac realnych w Polsce
PublicationStreszczenie W początkowej części artykułu zostały przedstawione i omówione informacje o poziomie miesięcznych nominalnych płac (WN) oraz indeksie cen dóbr konsumpcyjnych (ICK) w gospodarce polskiej w latach 1995-2015. Następnie opisano poziomy realnych płac (W) wyrażone w cenach roku 2015. Na bazie tych informacji przedstawiono i przedyskutowano zagadnienia dotyczące rocznych przyrostów płac realnych oraz ich rocznych stóp wzrostu....
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Power System Dynamics. Stability and Control. 3rd edition
PublicationComprehensive, state-of-the-art review of information on the electric power system dynamics and stability. It places the emphasis first on understanding the underlying physical principles before proceeding to more complex models and algorithms. The book explores the influence of classical sources of energy, wind farms and virtual power plants, power plants inertia and control strategy on power system stability. The book cover...
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Application of Analytic Signal and Smooth Interpolation in Pulse Width Modulation for Conventional Matrix Converters
PublicationThe paper proposes an alternative and novel approach to the PWM duty cycles computation for Conventional Matrix Converters (CMC) fed by balanced, unbalanced or non–sinusoidal AC voltage sources. The presented solution simplifies the prototyping of direct modulation algorithms. PWM duty cycles are calculated faster by the smooth interpolation technique, using only vector coordinates, without trigonometric functions and angles. Both...
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Voltage fluctuations on the main switchgear of the industrial power system supplying the rolling mill motors
Open Research DataThe dataset presents the voltage waveforms on the bus bars of the main switchgear of the industrial power network for the supply of rolling mills. The data was recorded during an experiment whose purpose was to determine a level of short-term and long-term flicker caused by voltage fluctuations. In the virtual application of flickermeter, a hardware...
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Methods for quality improvement of multibeam and LiDAR point cloud data in the context of 3D surface reconstruction
PublicationPoint cloud dataset is the transitional data model used in several marine and land remote-sensing applications. During further steps of processing, the transformation of point cloud spatial data to more complex models containing higher order geometric structures like edges and facets may be possible, if an appropriate quality level of input data is provided. Point cloud datasets usually contain a considerable amount of undesirable...
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Resonant and nonresonant excitation of waves in a planar magnetosonic flow
PublicationForced propagation of perturbations in a magnetosonic wave are considered. The driving force may be caused by stimulated Mandelstam–Brillouin scattering of optic waves or by intense magnetosonic exciter. Some heating-cooling function which takes into account radiative cooling and unspecified heating is taken into consideration, as well as nonlinearity of a medium. Both these factors make the excitation particular. The analytical...
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Core-Shell Nanoparticles with Hyperbranched Poly(arylene-oxindole) Interiors
PublicationCore-shell type star polymers composed of poly(tert-butyl acrylate) (poly(t-BuA)) arms and 100% hyperbranched poly(arylene-oxindole) interiors were synthesized via the "core-first" method. Atom transfer radical polymerization of t-BuA initiated by 2-bromopropionyl terminal groups of the hyperbranched core was applied for the synthesis of the stars. The resultant star structures were characterized by gel permeation chromatography...
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Anatomy of noise in quantitative biological Raman spectroscopy
PublicationRaman spectroscopy is a fundamental form of molecular spectroscopy that is widely used to investigate structures and properties of molecules using their vibrational transitions. It relies on inelastic scattering of monochromatic laser light irradiating the specimen. After appropriate filtering the scattered light is dispersed onto a detector to determine the shift from the excitation wavelength, which appears in the form of...
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Solid-State Modification of Poly(butylene terephthalate) with a Bio-Based Fatty Acid Dimer Diol Furnishing Copolyesters with Unique Morphologies
PublicationCopolyesters based on poly(butylene terephthalate) (PBT) and a bio-based fatty acid dimer diol (FADD) were prepared by solid-state modification (SSM). The chemical incorporation of the FADD into the backbone of the PBT was proven using various techniques. It was clear that the incorporation rate was diffusion-limited rather than reaction-limited. From quantitative 13C NMR a nonrandom chemical microstructure was obtained at all...
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Testing the Wide-Sense Stationarity of Bandpass Signals for Underwater Acoustic Communications
PublicationThe Underwater Acoustic Communication (UAC) systems work in communication channels characterized by a large variety of multipath propagation conditions that can additionally change over time. Designing a reliable communication system requires knowledge of the transmission parameters of the channel. There is a need for the development of adaptive signaling schemes that would dynamically optimize the signal parameters of the physical...
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Electron collisions with cyanoacetylene HC3N : Vibrational excitation and dissociative electron attachment
PublicationWe experimentally probe electron collisions with HC3N in the energy range from 0 to 10 eV with the focus on vibrational excitation and dissociative electron attachment. The vibrational excitation cross sections show a number of resonances which are mode specific: the two dominant π∗ resonances are visible in the excitation of all the vibrational modes; however, broad σ ∗ resonances are visible only in certain bond-stretching vibrational...
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Study of ZrS3-based field-effect transistors toward the understanding of the mechanisms of light-enhanced gas sensing by transition metal trichalcogenides
PublicationExtending knowledge of the properties of low-dimensional van der Waals materials, including their reactivity to the ambiance, is important for developing innovative electronic and optoelectronic devices. Transition metal trichalcogenides with tunable optical band gaps and anisotropic conductivity are an emerging class among low- dimensional structures with the possibility of gate tunability and photoreactivity. These properties...
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Light-Modulated Sunscreen Mechanism in the Retina of the Human Eye
PublicationThe functioning of the human eye in the extreme range of light intensity requires a combination of the high sensitivity of photoreceptors with their photostability. Here, we identify a regulatory mechanism based on dynamic modulation of light absorption by xanthophylls in the retina, realized by reorientation of pigment molecules induced by trans–cis photoisomerization. We explore this photochemically switchable system using chromatographic...
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Hierarchical dissolved oxygen control for activated sludge processes
PublicationA hierarchical controller for tracking the dissolved oxygen reference trajectory in activated sludge processes is proposed and investigated. The removal of nitrogen and phosphorous from wastewater is considered. Typically, an aeration system itself is a complicated hybrid nonlinear dynamical system with faster dynamics compared to the internal dynamics of the dissolved oxygen in a biological reactor. It is a common approach to...
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Effect of Cr and Mn doping on ferroelectric and dielectric properties of Li1.72Na0.28Ge4O9 single crystals
PublicationLi1.72Na0.28Ge4O9 single crystals pure and slightly doped with chromium and manganese, obtained by Czochralski growth, were investigated for their ferroelectric and dielectric properties. The change in stoichometry of Li2− x Na x Ge4O9 (x = 0.28) crystals doped with Cr and Mn (0.1 mol.%) had an influence on the value of ferroelectric-to-paraelectric phase transition temperature, T c. The applied doping affects the T c value by...
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A New Approach to the PWM Modulation for the Multiphase Matrix Converters Supplying Loads with Open-End Winding.
PublicationThis article presents three variants of the Pulse Width Modulation (PWM) for the Double Square Multiphase type Conventional Matrix Converters (DSM-CMC) supplying loads with the open-end winding. The first variant of PWM offers the ability to obtain zero value of the common-mode voltage at the load's terminals and applies only six switches within the modulation period. The second proposal archives for less Total Harmonic Distortion...
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Quality assessment of low voltage surge arresters
PublicationUsers expect reliable operation of the surge arrester during overvoltages, which may originate from a switching process or a lightning discharge. The necessary conditions to guarantee these expectations are: appropriate construction of the surge arrester, its production being maintained in accordance with technical standards, and a positive results of the type test (as well routine and acceptance tests). The recipient, especially...
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Transport properties of aqueous ionic liquid microemulsions: influence of the anion type and presence of the cosurfactant
PublicationTransport properties, viz. specific conductivity, dynamic viscosity and apparent diffusion coefficients, were measured as a function of water content in aqueous ionic liquid microemulsions containing 1-butyl-3- methylimidazolium hexafluorophosphate, [BMIM][PF6] and bis(trifluoromethanesulphonyl)imide, [BMIM][Tf2N], stabilized by the nonionic surfactant TX-100, or its mixture with a cosurfactant, i.e. butanol. The investigation covered...
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Nano-structured Pt embedded in acidic salts of heteropolymolybdate matrices: MS EXAFS study
PublicationA structural study of Pt nano-catalysts is presented in the paper. The innovation in the case of the considered catalytic materials resides in the use a meso-microporous inorganic matrix of heteropolyacid salt of composition X2.5H0.5YMo12O40 where X = Rb, Cs and Y = P, Si as a catalyst support. Metallic nanoparticles were created by platinum ions reduction in a hot H2/Argon stream and were mainly located into matrix pores. As the...
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Gold nanoparticles evaluation using functional optical coherence tomography
PublicationThe main object of this research was to assess the ability to characterize the gold nanoparticles using optical modalities like optical coherence tomography. Since the nanoparticles, especially gold one, have been very attractive for medical diagnosis and treatment the amount of research activities have been growing rapidly. The nanoparticles designed for different applications like contrast agents or drugs delivery change the...
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Micellar aggregation of Triton X-100 surfactant in imidazolium ionic liquids
PublicationIn this work we investigated aggregation behavior of a nonionic surfactant Triton X-100 in eighteen imidazolium ionic liquids (ILs) with two to eight carbon atoms in cations alkyl chain, namely 1-ethyl-3-methylimidazolium, [EMIM], 1-butyl-3-methylimidazolium, [PrMIM], 3-methyl-1-propylimidazolium, [BMIM], 1-hexyl-3-methylimidazolium, [PMIM], 3-methyl-1-pentyl-imidazolium, [HMIM], and 1-octyl-3-methylimidazolium, [OMIM], and with...
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Ball milling treatment of Mn3O4 regulates electron transfer pathway for peroxymonosulfate activation
PublicationHeterogeneous metal catalysts have attracted considerable interest in advanced oxidation processes (AOPs) for wastewater treatment by activating peroxymonosulfate (PMS). However, it remains challenging to the rational design of efficient reaction pathway for high-performance contaminants removal by regulating the inherent structure of metal oxides. Herein, a high-energy ball milling method was employed to modulate the electronic...
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Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublicationThe modern concept of a universal converter is intended as a power converter (PC) suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow easier integration of renewable energy sources and energy storage systems (ESSs), interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and...
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Assessment of Supercapacitor’s Quality by Means of Low Frequency Noise
PublicationLow frequency noise is a well-known tool for quality and reliability assessment of electronic devices. This phenomenon is observed in different electrochemical devices as well (e.g., smart windows, electrochemical corrosion processes). Thus, we can assume that the same tool can be used to asses quality of supercapacitors. Their quality is usually determined only by capacitance and/or equivalent series resistance (ESR), or impedance....
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ESPAR Antenna-Based WSN Node With DoA Estimation Capability
PublicationIn this paper, we present a low-cost energy-efficient electronically steerable parasitic array radiator (ESPAR) antenna-based wireless sensor network (WSN) node designed for IEEE 802.15.4 standard that is capable of performing direction of arrival (DoA) estimation in real-life outdoor environments. To this end, we propose the WSN node architecture, design and realization that utilizes NXP JN5168 radio frequency (RF) wireless transceiver...
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Tracing financial innovation diffusion and substitution trajectories. Recent evidence on exchange-traded funds in Japan and South Korea.
PublicationSince the rapid growth of the popularity of ETFs, the potential substitution between innovative financial products, exchange-traded funds (ETFs), and traditional investment funds (open-end and closed-end funds) is recognized as one of the most-discussed issues in the financial industry. This is the first study to empirically verify and compare the diffusion and substitution of ETFs using monthly data on their assets in two selected...
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Feasibility Study of Three-Phase Modular Converter for Dual-Purpose Application in DC and AC Microgrids
PublicationThe modern concept of a universal converter is intended as a power converter suitable for application in both dc or ac grids using the same external connectors. This novel family was recently proposed to allow an easier integration of renewable energy sources and energy storage systems, interfacing with dc/ac grids and/or loads with a minimum redundancy of power switches and passive elements. This kind of solution and applications...
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Kinetic characterization of hydrogen sulfide inhibition of suspended anammox biomass from a membrane bioreactor
PublicationThe inhibition effects of hydrogen sulfide (H2S) on anammox-enriched biomass from a laboratory membrane reactor were analyzed in a series of batch respirometric experiments. The determined half maximal inhibitory concentration (IC50) was 4.67 mg H2S-S L−1 at the constant pH = 7.0 and the total sulfide concentration varying between 1 and 15 mg TS-S L−1. In another test, the IC50 was found to be 4.25 mg H2S-S L−1 under a constant...
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Linear and Nonlinear Optical Properties of Azobenzene Derivatives Modified with an (Amino)naphthalene Moiety
PublicationThe design of two-photon absorbing azobenzene (AB) derivatives has received much attention; however, the two-photon absorption (2PA) properties of bis-conjugated azobenzene systems are relatively less explored. Here, we present the synthesis of six azobenzene derivatives and three bisazobenzenes substituted (or not) at para position(s) with one or two amino group(s). Their linear and nonlinear absorption properties are studied...
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Micelle formation of Tween 20 nonionic surfactant in imidazolium ionic liquids
PublicationAggregation behavior of polyoxyethylene (POE)-type nonionic surfactant Tween 20 in imidazolium ionic liquids with varying chain length and different anions, such as tetrafluoroborate, hexafluorophosphate, bis(trifluoromethanesulfonyl)imide, and trifluoromethanesulfonate, was investigated by means of surface tension, conductivity and dynamic light scattering measurements. The role of the chain length, anion size as well as interactions...
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Zero-pole approach to computer aided design of in-line siw filters with transmission zeros
PublicationThis paper presents a design of a new type of in-line pseudo-elliptic filters implemented in substrate integrated waveguide(SIW) technology. To realize transmission zeros in in-line topology,frequency-dependent couplings were used. Such dispersive couplingswere implemented as shorted stubs. The design process startswith the generation of a suitable starting point. To this end, anapproximation of SIW as a rectangular waveguide is...
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Implementation of FDTD-compatible Green's function on heterogeneous CPU-GPU parallel processing system
PublicationThis paper presents an implementation of the FDTD-compatible Green's function on a heterogeneous parallel processing system. The developed implementation simultaneously utilizes computational power of the central processing unit (CPU) and the graphics processing unit (GPU) to the computational tasks best suited to each architecture. Recently, closed-form expression for this discrete Green's function (DGF) was derived, which facilitates...
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Influence of Urea and Dimethyl Sulfoxide on K-Peptide Fibrillation
PublicationProtein fibrillation leads to formation of amyloids—linear aggregates that are hallmarks of many serious diseases, including Alzheimer’s and Parkinson’s diseases. In this work, we investigate the fibrillation of a short peptide (K-peptide) from the amyloidogenic core of hen egg white lysozyme in the presence of dimethyl sulfoxide or urea. During the studies, a variety of spectroscopic methods were used: fluorescence spectroscopy...
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Zero-Pole Approach in Microwave Passive Circuit Design
PublicationIn this thesis, optimization strategies for design of microwave passive structures including filters, couplers, antenna and impedance transformer and construction of various surroogate models utilized to fasten the design proces have been discussed. Direct and hybrid optimization methodologies including space mapping and multilevel algorithms combined with various surrogate models at different levels of fidelity have been utilized...
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Wieloobszarowa regulacja systemu turbogeneratora elektrowni jądrowej =Multiregional control of nuclear power plant turbogenerator system
PublicationW artykule przedstawiono propozycję zaawansowanej struktury sterowania układem turbogeneratora w szerokim zakresie zmian zapotrzebowania na moc czynną. Dla potrzeb syntezy tej struktury wykorzystano nieliniowe, dynamiczne modele turbiny parowej i generatora synchronicznego współpracującego z systemem elektroenergetycznym. Zaproponowane algorytmy sterowania oparte są odpowiednio o wieloobszarowe regulatory rozmyte, z lokalnymi regulatorami...
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WARUNKI REZONANSOWE W WĘŹLE Z KOMPENSATOREM SVC
PublicationInstalowanie kompensatorów statycznych w sieciach rozdzielczych i przesyłowych służy poprawie profili napięciowych. Kompensatory jako źródła mocy biernej zwiększają stabilność napięciową systemu. Pozwalają także na szybszą odbudowę systemu w przypadku awarii napięciowej. W artykule zaprezentowano wpływ struktury i wysterowania układu SVC na zmianę impedancji w układzie zasilania. Ma to bezpośredni wpływ na częstotliwości, przy...
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The experimental results of diesel fuel spray with marine engine injector
Open Research DataThe data set presents the measurement of the diesel fuel spray from with marine engine injector. The main target presents results is a study of the time course of macro parameters (spray tip penetration, spray cone angle) of fuel spray in the cylinder of marine diesel engine. The impact of ambient conditions and the geometrical parameters of the injector...
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Modelling long-term technological transition of Polish power system using MARKAL: Emission trade impact
PublicationThe need for technological transition of electricity production becomes a global problem. However, in coal-dominated Polish power system this need is even more crucial than anywhere, since technical lifetime of the most domestic power plants is ending. In this paper, the impact of the EU Emission Trading Scheme (EU ETS) for CO2 combined with sulfur dioxide (SO2) and nitrogen oxides (NOx) emission trading mechanism on power technology...
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Recent advances in hydrogen production from biomass waste with a focus on pyrolysis and gasification
PublicationThis paper presents the results research on the optimal fuel compositions and the control parameters of the spark ignition engine fueled with syngas-biogas-hydrogen for the purpose of setting up a flexible electronic control unit for the engine working in a solar-biomass hybrid renewable energy system. In syngas-biogas-hydrogen mixture, the optimal content of hydrogen and biogas is 20% and 30%, respectively. Exceeding these thresholds,...
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Rearrangeability in multicast Clos networks is NP-complete
PublicationPrzestrajalność w polach Closa z połączeniami jeden do jeden jest problemem wielomianowym. W pracy pokazano, że w polach z połączeniami jeden do wiele problem ten jest NP zupełny.Three-stage elos networks are commutation networks with circuit switching. So far, graph theory has been very useful tool for solving issues related to these networks with unicast connections. This is so because if elos network is represented as a bipartite...
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Integrated monitoring, control and security of Critical Infrastructure Systems
PublicationModern societies have reached a point where everyday life relies heavily on desired operation of critical infrastructures, in spite of accidental failures and/or deliberate attacks. The issue of desired performance operation of CIS at high security level receives considerable attention worldwide. The pioneering generic methodologies and methods are presented in the paper project for designing systems capable of achieving these...
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Algorithms and Tools for Intelligent Control of Critical Infrastructure Systems
PublicationCritical Infrastructure Systems (CIS) are spatially distributed and of a network structure. The dynamics are nonlinear, uncertain and with several time scales. There is a variety of different objectives to be reliably met under a wide range of operational conditions. The operational conditions are influenced by the disturbance inputs, operating ranges of the CIS, faults in the sensors and actuators and abnormalities occurring in...