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Search results for: SYSTEM LOSS MODEL
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A 0.5 V Nanowatt Biquadratic Low-Pass Filter with Tunable Quality Factor for Electronic Cochlea Applications
PublicationA novel implementation of an analogue low-power, second-order, low-pass filter with tunable quality factor (Q) is presented and discussed. The filter feature is a relatively simple, buffer-based, circuit network consisting of eleven transistors operating in a subthreshold region. Q tuning is accomplished by injecting direct current into a network node, which changes the output resistance of the transistors and, as a result, modifies...
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Pursuing Analytically the Influence of Hearing Aid Use on Auditory Perception in Various Acoustic Situations
PublicationThe paper presents the development of a method for assessing auditory perception and the effectiveness of applying hearing aids for hard-of-hearing people during short-term (up to 7 days) and longer-term (up to 3 months) use. The method consists of a survey based on the APHAB questionnaire. Additional criteria such as the degree of hearing loss, technological level of hearing aids used, as well as the user experience are taken...
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Data Acquisition and Processing for GeoAI Models to Support Sustainable Agricultural Practices
PublicationThere are growing opportunities to leverage new technologies and data sources to address global problems related to sustainability, climate change, and biodiversity loss. The emerging discipline of GeoAI resulting from the convergence of AI and Geospatial science (Geo-AI) is enabling the possibility to harness the increasingly available open Earth Observation data collected from different constellations of satellites and sensors...
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Isoprostanes-Biomarkers of Lipid Peroxidation: Their Utility in Evaluating Oxidative Stress and Analysis
PublicationIsoprostanes (IsoPs) are key biomarkers for investigating the role of free radical generation in the pathogenesis of human disorders. To solve IsoPs-related problems with regard to isoprostanes, analytical tools are required. This paper reviews the problems and trends in this field focusing on the methodology for assaying biomarkers in exhaled breath condensate (EBC) samples. A large amount of work has been done in the qualitative...
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Degradation of polycaprolactone modified with TPS or CaCO3 in biotic/abiotic seawater
PublicationThis paper is an investigation of the polymer degradation process in two types of seawater (with and without microorganisms) sourced from the Baltic Sea. The chosen polymeric materials were polycaprolactone modified with either thermoplastic starch (PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3) compared directly against unmodified polycaprolactone. All samples were incubated for 28 weeks in seawater with and without microorganisms...
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A study of cavitation erosion resistance of an ion nitrided titanium alloy by means of the vibration and rotating disk methods
PublicationIn this work, a comparative analysis of the cavitation erosion resistance of the Ti– 6.7Al–2.5Mo–1.8Cr–0.5Fe–0.25Si alloy (known as brand VT3-1) before and after lowtemperature ion nitriding is carried out. Two test methods were applied, using vibrative (ASTM G-32) and rotating disk rigs, respectively. The kinetic dependences of the erosive destruction of samples of titanium alloy VT3-1 in the initial state, after ion nitriding...
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Implementation of Extended Kalman Filter with Optimized Execution Time for Sensorless Control of a PMSM Using ARM Cortex-M3 Microcontroller
PublicationThis paper addresses the implementation and optimization of an Extended Kalman Filter (EKF) for the Permanent Magnet Synchronous Motor (PMSM) sensorless control using an ARM Cortex-M3 microcontroller. A various optimization levels based on arithmetic calculation reduction was implemented in ARM Cortex-M3 microcontroller. The execution time of EKF estimator was reduced from 260.4 μs to 37.7 μs without loss of accuracy. To further...
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Nanocrystallization as a tool for controlling in vitro dissolution of borophosphate glass
PublicationThe controlled nanocrystallization of sodium-calcium-borophosphate glass (Na16.6Ca5.1B10.5Al0.8P10.5 O56.5 in at %) was conducted to investigate its influence on in vitro dissolution. Three temperatures (570 ◦C, 590 ◦C, and 610 ◦C) were selected based on thermal analysis and investigation of the morphology, structure, and in vitro dissolution of glass and glass-ceramics was conducted. The results of X-ray diffraction confirmed...
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Evaluation of fire hazard in electrical installations due to unfavorable ambient thermal conditions
PublicationEvaluation of fire hazard caused by electrical installations is a difficult and important topic, and it limits the possibility of loss of life or health of people, as well as the occurrence of significant property damage. In particular, this hazard was caused by power cables and especially photovoltaic (PV) installations. The authors proved that power cables directly exposed to strong solar radiation are likely to exceed maximum...
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Shielded HMSIW-Based Self-Triplexing Antenna With High Isolation for WiFi/WLAN/ISM Band
PublicationThis article presents a novel design of a miniaturized self-triplexing antenna (STA) based on the shielded half-mode substrate integrated waveguide (S-HMSIW) for WiFi/WLAN/ISM-band applications. The S-HMSIW is constructed by assembling one row of vias and an open slot at the open-ended side of the conventional HMSIW. This configuration increases the quality factor and minimizes unwanted radiation loss, which allows for achieving...
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ASSESSMENT OF GOLD AND/OR CRUDE OIL AS INVESTMENTS FOR PORTFOLIO DIVERSIFICATION. A WARSAW STOCK EXCHANGE CASE STUDY
PublicationThe purpose of the study is to assess whether the inclusion of investments in gold and/or crude oil improves an investment portfolio consisting of shares of enterprises included in the WIG20 index (traditional invest-ments). All possible combinations of investment portfolios with minimal risk and maximum efficiency were tested. The portfolios were determined based on Markowitz’s portfolio theory. All results were compared...
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Low energy inelastic electron scattering from carbon monoxide: II. Excitation of the b3Σ+, j3Σ+, B1Σ+, C1Σ+ and E1Π Rydberg electronic states
PublicationIn this second part of a two part paper (first part: Zawadzki et al (2020 J. Phys. B: At. Mol. Opt. Phys. 53 165201)) we present differential scattering cross sections for excitation of several Rydberg electronic states of carbon monoxide by electron impact. The first part concerned the low-lying valence states of CO. In the present study cross sections are obtained experimentally using low-energy electron energy-loss spectroscopy...
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Hybrid Model of Axially Moving Continua
PublicationThe paper introduces the method of the model reduction of systems that experience a Coriolis acceleration component. It causes that system equations are non-self-adjoined. To avoid such problem modal, reduced model is built up for the system without Coriolis acceleration terms which are next included by application of any lumping technique. Hence, the final reduced model is a hybrid one, obtained by both lumping and modal methods...
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Inteligentne systemy agentowe w systemach zdalnego nauczania
PublicationW pracy omówiono inteligentne systemy agentowe w systemach zdalnego nauczania. Po krótkim przedstawieniu ewolucji systemów zdalnego nauczania i ich wybranych zastosowań, scharakteryzowano inteligentne agenty edukacyjne. Omówiono wykorzystanie programowania genetycznego oraz algorytmów neuro-ewolucyjnych do implementacji oprogramowania tej klasy. Ponadto, nawiązano do modelu Map-Reduce, który efektywnie wspiera architekturę nowoczesnego...
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Hybrid model of moving or rotating continua
PublicationThe paper introduces the method of the model reduction of systems that experience a Coriolis acceleration or gyroscopic effect component. In such causes that corresponding system equations are non-self-adjoined. Modal reduced model is built up for the system without Coriolis or gyroscopic effect terms. These phenomena are next included by application of any lumping technique. Hence, the final reduced model is a hybrid one, obtained...
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Musical instrument sound separation methods supported by artificial nueural network decision system
PublicationRozprawa doktorska (27 czerwica 2006).Celem prowadzonych prac badawczych było opracowanie algorytmów separacji dźwięków instrumentów muzycznych. Dodatkowo dobrano zestaw parametrów tak aby możliwe było wytrenowanie sztucznej sieci neuronowej w celu automatycznego rozpoznawania odseparowanych sygnałów. Zaproponowano również aby algorytm decyzyjny odpowiedzialny za klasyfikacje dźwięków pełnił funkcję automatycznej metody oceny algorytmów...
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Novel method of estimation of inertial and dissipative parameters of a railway pantograph model
PublicationAn increase in electric railway vehicles service velocity requires that correct interaction between the pantograph and the catenary is ensured. This implies the need for developing mathematical models of pantographs and catenaries and determining their parameters. The article presents a method to determine parameters of mechanical joints of a railway pantograph based on analysis of pantograph subassemblies in swinging motion. The...
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Sterowanie predykcyjne i fuzja danych w systemie dynamicznego pozycjonowania statku
PublicationRozprawa doktorska poświęcona jest badaniu zastosowania fuzji danych oraz sterowania predykcyjnego w systemie dynamicznego pozycjonowania statku. W pierwszej części pracy przedstawiono historię rozwoju systemów dynamicznego pozycjonowania, różne metody estymacji położenia statku, metody sterowania oraz cel i tezę pracy. Następnie zaprezentowano model matematyczny statku, kinematykę oraz dynamikę. W kolejnej części przedstawiono...
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Fermentative Conversion of Two-Step Pre-Treated Lignocellulosic Biomass to Hydrogen
PublicationFermentative hydrogen production via dark fermentation with the application of lignocellulosic biomass requires a multistep pre-treatment procedure, due to the complexed structure of the raw material. Hence, the comparison of the hydrogen productivity potential of different lignocellulosic materials (LCMs) in relation to the lignocellulosic biomass composition is often considered as an interesting field of research. In this study,...
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Fatal N-Ethylhexedrone Intoxication
PublicationN-Ethylhexedrone [2-(ethyloamino)-1-phenylhexan-1-one; α-ethylaminohexanophenone; NEH] is one of the most recent synthetic cathinones that appeared on the illegal market in late 2015. The majority of information concerning the model of consumption of NEH and its impact on the body originates only from self-reports from grey literature websites and drug forums. There are only limited data associated with the concentrations of NEH...
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Analysis of a gene expression model
PublicationWe study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the number of active binding sites, the way in which dimers bind to DNA and time delay in translation process. For a simplified model that consist of three ordinary differential equations with time delay we derive conditions for stability of the positive steady state and for the...
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Application of muscle model to the musculoskeletal modeling
PublicationThe purpose of this paper is to investigate new fusiform muscle models. Each of these models treats a muscle as a system composedof parts characterized by different mechanical properties. These models explain the influence of differences in the stiffness of lateral parts and the degree of muscle model discretization. Each muscle model is described by a system of differential equations and a single integro-differential equation....
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Badanie stanu nawierzchni drogowej z wykorzystaniem uczenia maszynowego
PublicationW artykule opisano budowę systemu informowania o stanie nawierzchni drogowej z wykorzystaniem metod cyfrowego przetwarzania obrazów oraz uczenia maszynowego. Efektem wykonanych prac badawczych jest eksperymentalna platforma, pozwalająca na rejestrację uszkodzeń na drogach, system do analizy, przetwarzania i klasyfikacji danych oraz webowa aplikacja użytkownika do przeglądu stanu nawierzchni w wybranej lokalizacji.
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Verification of the Analytical Traffic Model of a Multidomain IMS/NGN Using the Simulation Model
PublicationIn this paper we verify the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). For this reason a proper simulation model used, in which not theoretical queuing system models but the operation of real network elements and standardized call scenarios are accurately implemented. Consequently,...
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System pozycjonowania dynamicznego morskich jednostek pływających jako system mechatroniczny
PublicationW artykule przedstawiano system pozycjonowania dynamicznego półzanurzeniowej platformy wiertniczej, który jest rozpatrywany jako system mechatroniczny. W szczególności zaś zaprezentowano systemy referencyjne utrzymania stanowiska pozycyjnego na morzu, urządzenia nawigacyjne, czujniki ruchów własnych jednostki pływającej i anemometry rozważane jako czujniki systemu mechatronicznego oraz pędniki azymutalne rozważane jako nastawniki...
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A laboratory model of an inspection vehicle. [Model laboratoryjny pojazdu inspekcyjnego]
PublicationW pracy opisano konstrukcję laboratoryjnego modelu pojazdu inspekcyjnego oraz zaproponowano system wielowątkowego sterowania pojazdem. Do budowy autonomicznego pojazdu wykorzystano napędzany elektrycznie już istniejący model laboratoryjny samochodu osobowego. Konstruowany pojazd wyposażono w specjalnie zaprojektowane elektroniczne układy czujnikowe pozwalające wykrywać i śledzić zaznaczoną kolorem czarnym trasę oraz mierzyć odległości...
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SIMPLIFIED DYNAMIC MODEL OF ROTATING BEAM
PublicationIn the paper a hybrid model of rotating beam is presented. It was obtained by using two methods: modal decomposition and spatial discretization. Reduced modal model was built for the system without the load related to inertia forces that occur during beam rotation. This inertia load was next modeled by using the method of simply spatial discretization and combined with reduced modal model. This approach allows to obtain accurate...
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A Method of MOS Evaluation for Video Based Services
PublicationThis paper deals with a method for QoE evaluation for the services transmitting large amount of data perceived by the end user in relatively short time periods, e.g. streaming video in mobile operator...
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Engineering Challenges in the Design of Cochlear Implants
PublicationHearing aids such as cochlear implants have been used by both adults and children for a long time. In addition, cochlear implants are used by patients who have severe hearing loss either by birth or after an accident. This paper aims to investigate the engineering challenges bounding the design of cochlear implants and present its possible solution...
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Knowledge Sharing and Creativity: Individual and Organizational Perspective
PublicationThe flow of knowledge between employees contributes to the knowledge development which in turn influences individual and organizational creativity. However knowledge sharing by employees is not a simplistic and homogeneous behaviour. Basing on the literature review in the area of intraorganizational knowledge sharing and creativity, the author aims to explain the relation between giving knowledge and individual (giver) creativity,...
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(Lost) Pride and Prejudice. Journalistic Identity Negotiation Versus the Automation of Content
PublicationThe objective of our research was to broaden the knowledge regarding the relationship between the work of journalists and their professional identity, and, in particular, to identify the attitudes of this professional group towards algorithmic content creation under conditions of liminality. Previously, the implementation of the technology of algorithmic content creation by media organisations was associated primarily with financial...
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Polyurethane glycolysate from industrial waste recycling to develop low dielectric constant, thermally stable materials suitable for the electronics
PublicationWe are utilizing a new method to improve the dielectric properties of a conventional polymer using a recycled polymer product. The polyurethane foams are recycled by glycolysis process and the derived material was applied to improve the dielectric properties of the brittle DGEBA epoxy resin. Two main parameters that determine the applicability of the material as a dielectric (the dielectric constant and dielectric loss), were studied...
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Reducing common mode voltage and bearing currents in quasi - resonant DC - link inverter
PublicationIn the paper, a concept of separation of an inverter-fed induction motor drive from its mains supply by two transistor switches inserted in the dc-link circuit is reexamined based on the proposed parallel quasi-resonant dc-link inverter (PQRDCLI). The objective of the paper is to show an advantage of the proposed topology in limiting high frequency common mode voltage and bearing currents. In the laboratory setup, an induction...
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Predicting cutting power for band sawing process of pine and beech wood dried with the use of four different methods
PublicationWood drying is an important stage in the woodworking process. After drying, wood is subject to a re-sawing process, for which a high quality surface, low material loss, and high efficiency are often required. In this paper, forecasted values were presented of cutting power for the re-sawing process of pine and beech wood that were dried with four different methods. Forecasting of cutting power for an industrial band saw machine...
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A design framework for rigorous constrained EM-driven optimization of miniaturized antennas with circular polarization
PublicationCompact radiators with circular polarization are important components of modern mobile communication systems. Their design is a challenging process which requires maintaining simultaneous control over several performance figures but also the structure size. In this work, a novel design framework for multi-stage constrained miniaturization of antennas with circular polarization is presented. The method involves sequential optimization...
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Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublicationThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...
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Ac and dc conductivities in v2o5-p2o5 glasses containing alkaline ions
PublicationWe investigated the ac and dc conductivity in 50V2O5-(50 − x)P2O5-xA2O (A = Li, Na, K) glasses as a function of temperature. The measurements were carried out in the frequency range from 10−4 to 107 Hz. For all compositions, the dc conductivity decreased with the increasing alkali ion content. The decrease in conductivity was more pronounced for larger alkali ions. The ac conductivity exhibited a universal dynamic response: σac...
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The problem of infections associated with implants – an overview
PublicationImplant-associated infections are serious and relatively common complication that leads to implant loss. The purpose of this paper is to gather knowledge about this issue. A literature review of the epidemiology, risk factors and pathogenesis of infections related to implants was carried out. This position collects data on commonly used implants and infections associated with them from various fields of medicine and contains classifications...
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Measurements of OF QoS/QoE parameters for media streaming in a PMIPv6 TESTBED WITH 802.11 b/g/n WLANs
PublicationA growing number of mobile devices and the increasing popularity of multimedia services result in a new challenge of providing mobility in access networks. The paper describes experimental research on media (audio and video) streaming in a mobile IEEE 802.11 b/g/n environment realizing network-based mobility. It is an approach to mobility that requires little or no modification of the mobile terminal. Assessment of relevant parameters...
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Information Retrieval in Wikipedia with Conceptual Directions
PublicationThe paper describes our algorithm used for retrieval of textual information from Wikipedia. The experiments show that the algorithm allows to improve typical evaluation measures of retrieval quality. The improvement of the retrieval results was achieved by two phase usage approach. In first the algorithm extends the set of content that has been indexed by the specified keywords and thus increases the Recall value. Then, using the...
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Multidecadal (1960-2011) shoreline changes in Isbjornhamna (Hornsund, Svalbard)
PublicationAsection of a gravel−dominated coast in Isbjørnhamna (Hornsund, Svalbard) was analysed to calculate the rate of shoreline changes and explain processes controlling coastal zone development over last 50 years. Between 1960 and 2011, coastal landscape of Isbjørn− hamna experienced a significant shift from dominated by influence of tide−water glacier and protected by prolonged sea−ice conditions towards storm−affected and rapidly...
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Effect of Different Bromine Sources on the Dual Cation Mixed Halide Perovskite Solar Cells
PublicationRecent research has shown that perovskite solar cells with a mixed dual A-cation have much better structural stability without loss of efficiency than single cation devices. Mixed cation perovskites create a lot of questions about the salts being used for the formation of the best-quality layer. Here, we have investigated three sources of bromide in the perovskite absorption layer, using lead bromide (PbBr2), formamidinium bromide...
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EVALUATION OF THE USE OF M2M-TYPE NB-IoT AND LTE TECHNOLOGIES FOR MARITIME COMMUNICATION SYSTEMS
PublicationThe development of IoT (the Internet of Things) wireless transmission opens a new era in communication systems. In the next years, the development and implementation of IoT systems will be very dynamic. It can be seen that the solutions of LTE – NB-IoT (Long Term Evolution – Narrowband IoT) transmission devices are implemented in a wide range of terrestrial solutions, e.g. smart grids. This paper aims to analyse the possibility...
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Assessment of Corrosive Behaviour and Microstructure Characterization of Hybrid Friction Stir Welded Martensitic Stainless Steel
PublicationThis study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using...
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An integral-differential method for impedance determination of the hydrogen oxidation process in the presence of carbon monoxide in the proton exchange membrane fuel cell
PublicationThe impedance of a proton exchange membrane fuel cell powered by hydrogen contaminated with carbon monoxide, ranging from 150 to 300 ppb, is measured and discussed. The tested range of CO concentration complied with the fuel standard specified in the ISO standards. Studies of influence of CO contamination on operation of PEMFC are crucial for further development and commercialization of fuel cells for automotive applications. Based...
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Fast Fading Characterization for Body Area Networks in Circular Metallic Indoor Environments
PublicationWith the increasing development of 5G and Body Area Network based systems being implemented in unusual environments, propagation inside metallic structures is a key aspect to characterize propagation effects inside ships and other similar environments, mostly composed of metallic walls. In this paper, indoor propagation inside circular metallic structures is addressed and fast fading statistical distributions parameters are obtained...
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Assessment of the impact of bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes)
PublicationThe assessment of the impact of the bacteria Pseudomonas denitrificans, Pseudomonas fluorescens, Bacillus subtilis and yeast Yarrowia lipolytica on commercial poly(ether urethanes) Tecoflex® and Tecothane® is presented. The polyurethane samples were incubated with pure cultures of the microorganisms at 30 °C for five months. The changes in the chemical structure of the polymers were evaluated using loss of weight and contact angle...
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Topological extraordinary optical transmission
PublicationΤhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 10^4-10^5 or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at...
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Model of identification of events and accident scenarios for a method of risk and safety assessment of ships in damaged conditions
PublicationW pracy opisano podstawowe problemy związane z identyfikacją zdarzeń i scenariuszy wypadku oraz modelowaniem ryzyka dla alternatywnej metody oceny bezpieczeństwa statków w stanie uszkodzonym. Zastosowano podejście do bezpieczeństwa statków oparte na ocenie zachowania się statku i ocenie ryzyka wypadku. Wskazano możliwości zastosowania modelowania do analizy bezpieczeństwa statków na etapie projektowania, w czasie eksploatacji i...
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Problemy modelowania liczby podróży generowanych i absorbowanych na przykładzie Gdańska
PublicationJedną z podstawowych danych niezbędnych do planowania elementów systemu transportowego jest informacja o liczbie podróży odbywanych na analizowanym obszarze. Dane te uzyskiwane są najczęściej za pomocą symulacyjnych modeli transportowych. Jednym z istotnych elementów i pierwszym etapem najczęściej stosowanego, klasycznego modelu czterostopniowego jest modelowanie liczby podróży generowanych i absorbowanych, podczas którego to...