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Search results for: DISCRETE-TIME SYSTEMS
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Time-Domain Description of Point-Source Acoustic Wavefields as a Useful Approach in Ultrasonic Techniques
PublicationIn traditional acoustics, field problems are usually treated in the frequency domain, broadband fields being reduced to superposition of harmonic spectrum components. However, this approach is inherently acausal and it is known that in case of arbitrary signals, the distribution-based, time-domain description can be more effective. The present paper is an attempt to expand the time-domain linear systems formalism onto space problems...
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Approximative sequences and almost homoclinic solutions for a class of second order perturbed Hamiltonian systems
PublicationIn this work we will consider a class of second order perturbed Hamiltonian systems with a superquadratic growth condition on a time periodic potential and a small aperiodic forcing term. To get an almost homoclinic solution we approximate the original system by time periodic ones with larger and larger time periods. These approximative systems admit periodic solutions, and an almost homoclinic solution for the original system...
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A new method for real-time monitoring of volatiles in frying fumes using proton transfer reaction mass spectrometry with time-of-flight analyse
PublicationTo safeguard the consumers’ well-being, it is necessary to develop novel methods for determination of carcinogens in food, including volatiles generated during frying. The currently used procedures for analysis of volatile fraction of vegetable oils are not based on real-time measurements and thus do not enable the determination of carcinogenic compounds in frying fumes; instead, only the headspace or liquid fraction is sampled....
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Research on GNSS satellite navigation systems
PublicationThis article contains results of research on two GNSS systems, i.e. GPS and GLONASS. Architectures, signal structures and navigation messages of both systems have been described. Some selected investigation results, concerning receiver performance in presence of interference, have been presented.
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Chirp-rate estimation of FM signals in the time-frequency domain
PublicationNovel dynamic representations of a complex signal in the time-frequency domain including: a channelized instantaneous complex frequency (CICF), a complex local group delay (CLGD) and a channelized instantaneous chirp-rate (CICR) are introduced. The proposed approach is based on the use of the gradient of the short-time Fourier transform complex phase. An interpretation of the newly-introduced distributions especially of the CICR...
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Evaluation of time-efficiency of disjoint paths calculation schemes
PublicationThe concept of alternate paths has been shown in the literature to provide fast response of a network to failures of its elements (nodes/links) affecting flows along the primary communication paths. Various approaches have been proposed to reduce the time necessary to redirect the respective flows onto the alternate paths. In this paper, we focus on another important objective, that so far has not received much attention, i.e.,...
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2022/2023 Global Digital Transformation-Full time - bachelor
e-Learning Courses -
Real-time speech streching for supporting hearing impaired schoolchildren
PublicationA study of time scale modification algorithms applied to support hearing impaired schoolchildren is presented. Variety of algorithms are considered, namely: overlap-and add, two variations of synchronous overlapand- add, and the phase vocoder. Their effectiveness as well as real-time processing capabilities are examined.
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General solution of quantum mechanical equations of motion with time-dependent Hamiltonians: A Lie algebraic approach
PublicationThe unitary operators U(t), describing the quantum time evolution of systems with a time-dependent Hamiltonian, can be constructed in an explicit manner using the method of time-dependent invariants. We clarify the role of Lie-algebraic techniques in this context and elaborate the theory for SU(2) and SU(1,1). In these cases we give explicit formulae for obtaining general solutions from special ones. We show that the constructions...
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[ITiT] Transmission Channel in Radio Communication Systems
e-Learning Courses{mlang pl} Dyscyplina: informatyka techniczna i telekomunikacja Zajęcia fakultatywne dla doktorantów II roku Prowadzący: dr hab. inż. Sławomir Ambroziak, prof. PG Liczba godzin: 15 Forma zajęć: wykład {mlang} {mlang en} Discipline: technical informatics and telecommunications Elective course for 2nd-year PhD students Academic teachers: dr hab. inż. Sławomir Ambroziak, prof. PG Total hours of training: 15 teaching hours Course...
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Closure on survival time
PublicationArtykuł zamyka sprawę przewracania statków w stanie awaryjnym, tj. czasu jaki upływa od momentu kolizji do momentu przewrócenia pod wpływem fal.
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Systems of Nonlinear Fractional Differential Equations
PublicationUsing the iterative method, this paper investigates the existence of a unique solution to systems of nonlinear fractional differential equations, which involve the right-handed Riemann-Liouville fractional derivatives D(T)(q)x and D(T)(q)y. Systems of linear fractional differential equations are also discussed. Two examples are added to illustrate the results.
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The influence of historical conditions on time and cost of construction project
PublicationConducting construction works in a building or in an area entered in the historic register is associated with the contracting authority's risk of incurring higher than planned costs of works, as well as delays in their implementation. In many cases, these deviations are completely independent of contracting authority and contractor. The aim of this article is to indicate the reasons for cost and time changes in the construction...
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Measurements and Measurement Systems [2022/23]
e-Learning CoursesOpis kursu: (np. numer semestru, dla którego przeznaczony jest kurs, cel lub tematyka przedmiotu) IV semestr kierunku Energy Technologies. Celem kursu jest zapoznanie teoretyczne i praktyczne studentów z podstawowymi i zaawansowanymi metodami pomiarowymi różnych wielkości pomiarowych oraz budową i zasadą działania systemów pomiarowych. The aim of the course is to introduce theoretical and practical students with basic...
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Operation of reed systems used to stabilization of sewage sludge
PublicationThe aim of this research was to determine the parameters of property operation of reed systems. It was also checked the possibility to use sludge in agriculture for the sake of heavy metal concentrations.The research was conducted in four Danish objects utilized sludge located in Helsinge, Vallo, Rudkobing and Nakskov near Copenhagen.It was found that correct operation of reed basins requires the determination of optimal doses...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Comparative analysis of switched reluctance motor control algorithms
PublicationПредмет исследования. Развитие микропроцессорной техники и силовой электроники позволило создавать недорогие и эффективные системы управления различными электромеханическими объектами, которые ранее широко не использовались из-за сложности управления. К таким устройствам можно отнести вентильно-индукторные электрические машины. Данные машины широко применяются в различных практических разработках, например, в тяговом электроприводе,...
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublicationThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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Utilising IT-based systems in regatta management
PublicationThe development and increasing accessibility of new technologies has brought changes to the management of sailing regattas. Organisational and promotional difficulties faced by the organisers are now being tackled with software-based systems. This article considers various information technology (IT) systems, designed to support the organisation and presentation of sailing regattas and explores how they are perceived by regatta...
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Speech codec enhancements utilizing time compression and perceptual coding
PublicationA method for encoding wideband speech signal employing standardized narrowband speech codecs is presented as well as experimental results concerning detection of tonal spectral components. The speech signal sampled with a higher sampling rate than it is suitable for narrowband coding algorithm is compressed in order to decrease the amount of samples. Next, the time-compressed representation of a signal is encoded using a narrowband...
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Towards automation of IT systems repairs
PublicationMonitoring and repair are two sides of the on-the-fly maintenance of IT systems.Monitoring is well supported by automatic tools. In contrast, repairs involve much higherhuman intervention which negatively affects reliability and efficiency. The paper intro-duces a method of automating repairs of IT systems which can be integrated with any ofthe existing monitoring mechanisms. The method is described as a collection of modelsand...
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Verification of a Novel Method of Detecting Faults in Medium-Voltage Systems with Covered Conductors
PublicationThis paper describes the use of new methods of detecting faults in medium-voltage overhead lines built of covered conductors. The methods mainly address such faults as falling of a conductor, contacting a conductor with a tree branch, or falling a tree branch across three phases of a medium-voltage conductor. These faults cannot be detected by current digital relay protection systems. Therefore, a new system that can detect the...
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On various modelling approaches to real-time visualisation of blood flow
PublicationThis paper reviews various modelling approaches to real-time visualisation of blood flow. These include classic, macroscale approach based on the momentum conservation equation together with a proper constitutive equation. Moreover, modern micro- and mesoscale approaches, such as molecular dynamics and dissipative particle dynamics, are discussed. Advantages and disadvantages of the discussed methods are highlighted with particular...
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Open shop problem with zero-one time operations and integer release date/deadline intervals
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Alternative Energy: Photovoltaic Modules and Systems
PublicationUse of solar energy does not contribute to global warming. The light-to-current conversion (photovoltaic conversion) takes place within solar cells, which in most cases are made of silicon. Solar module consists of many solar cells, which are electrically connected and placed between glass or Tedlar® and framed by an aluminium frame. A number of solar modules and other components form photovoltaic systems. In this entry, a brief...
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Semantic Integration of Heterogeneous Recognition Systems
PublicationComputer perception of real-life situations is performed using a variety of recognition techniques, including video-based computer vision, biometric systems, RFID devices and others. The proliferation of recognition modules enables development of complex systems by integration of existing components, analogously to the Service Oriented Architecture technology. In the paper, we propose a method that enables integration of information...
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PHONEME DISTORTION IN PUBLIC ADDRESS SYSTEMS
PublicationThe quality of voice messages in speech reinforcement and public address systems is often poor. The sound engineering projects of such systems take care of sound intensity and possible reverberation phenomena in public space without, however, considering the influence of acoustic interference related to the number and distribution of loudspeakers. This paper presents the results of measurements and numerical simulations of the...
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Dedicated scheduling of tasks to minimize mean flow time
PublicationThis paper investigates the complexity of scheduling biprocessor tasks on dedicated processors to minimize mean flow time. Since the general problem is strongly NP-hard, we assume some restrictions on task lengths and the structure of associated scheduling graphs. Of particular interest are acyclic graphs. In this way we identify a borderline between NP-hard and polynomially solvable special cases.
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Influence of passive house technology on time and cost of construction investment
PublicationDue to the changes in the energy standards for housing in Poland there are many concerns. Is the standard required by the regulation achievable and if it is, then at what cost? There are many solutions to construct a building in line with the requirements of passive house technology. They are differentiated by price and time required for implementation. This study is based on the solution proposed by one of Polish companies, offering...
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Audible noise in ship’s electrical drive systems with frequency converters
Open Research DataThe presented dataset is part of research focusing on the impact of the ship's electrical drive systems with frequency converters on vibrations and the level of audible noise on ships.
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INFORMATION SYSTEMS MANAGEMENT, Winter 2022-2023
e-Learning Courses„INFORMATION SYSTEMS MANAGEMENT” for students IM 2022-2023
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Time series of Doppler blood flow recordings
Open Research DataVital signals registration plays a grate role in biomedical engineering and education process. Well acquired data allow future engineers to observe certain physical phenomenons as well learn how to correctly process and interpret the data. This data set was designed for students to learn about Doppler phenomena and to demonstrate correctly and incorrectly...
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Excision-preserving cubical approach to the algorithmic computation of the discrete Conley index
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Ultracapacitor modeling and control with discrete fractional order artificial neural network
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Methods and means of processing discrete information in networks with a high level of noise
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Analysis of continuous-to-discrete transformation effect on a synthesis filter bank project
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Prediction of CO2 emissions of a car using the discrete map of the operating conditions
PublicationW pracy przedstawiono propozycję opisu warunków eksploatacji pojazdów w wybranej aglomeracji miejskiej z użyciem dyskretnej mapy warunków eksploatacji. Mapa taka umożliwia prognozowanie wybranych parametrów eksploatacyjnych pojazdów dla przyjętych dróg przejazdu oraz różnych jednostek napędowych. Głównymi parametrami wyznaczanymi z użyciem dyskretnej mapy warunków eksploatacji są: całkowita energia przeznaczana do napędu wybranego...
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Magnetizabilities of relativistic hydrogenlike atoms in some arbitrary discrete energy eigenstates
PublicationWe present the results of numerical calculations of magnetizability of the relativistic hydrogenlike atoms. Exploiting the analytical formula for $\chi$ we have found the values of the magnetizability for the ground state and for the first and the second set of excited states of the atom. The results for ions with the atomic number $0
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Modelling of localization of deformation in quasi-brittle materials with a continuum and discrete model
PublicationW artykule przedstawiono wyniki obliczeń lokalizacji odkształceń w materiałach kruchych przy zastosowaniu 2 modeli w ramach mechaniki ośrodka ciągłego i jednego modelu w ramach ośrodka dyskretnego. W przypadku pierwszy zastosowano model sprężysto-plastyczny i model zniszczeniowy rozszerzony o długość charakterystyczną mikrostruktury. W przypadku drugim przyjęto model rusztowy złożony z beleczek.
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PROBLEMS OF EXPERIMENTAL DETERMINATION OF COEFFICIENTS OF THE WEAR OF SHIP PIPING SYSTEMS
PublicationThe article presents series of considerations relating to experimental evaluation of the reliability of ship piping systems. The aim of this study is to attempt to answer the following questions: What should be the tested element? How to choose the diameter of the tested item? What should be the result of measurements and calculations? How to measure? How to choose the duration of the test? How to choose the sample size and elaborate...
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A link between seasonality and radiation-related toxicity: The big time or time will tell?
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Dynamical nonlocality in quantum time via modular operators
PublicationWe formalize the concept of the modular energy operator within the Page and Wootters timeless framework. As a result, this operator is elevated to the same status as the more studied modular operators of position and momentum. In analogy with dynamical nonlocality in space associated with the modular momentum, we introduce and analyze the nonlocality in time associated with the modular energy operator. Some applications of our...
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Approaching Secure Industrial Control Systems
PublicationThis study presents a systematic approach to secure industrial control systems based on establishing a business case followed by the development of a security programme. To support these two fundamental activities the authors propose a new method for security cost estimation and a security assessment scheme. In this study they explain the cost evaluation technique and illustrate with a case study concerning the assessment of the...
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Altruists will be altruists, but what about individualists? The role of future time perspective and social value orientation in volunteers’ declarations to continue engagement in three time horizons
PublicationVolunteering involves caring for the outcomes of others and typically long-term orientation so that one can achieve goals that are not always clearly visible in the short term. As with any activity, volunteering attracts people of different social value orientations – some rather individualistic, some rather altruistic. The aim of the study was to find out whether the future time perspective, which promotes thinking about future...
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The Efficiency of Post‐Communist Countries’ Health Systems
PublicationHealth‐care costs are a major financial burden for the transition economies, which have experienced rapidly increasing demand for health‐care services. The former communist countries of the Central and Eastern Europe and Central Asia needed to reform the financing of their health‐care systems and make efforts to strengthen the role of primary care while limiting the role of hospital care. The growing health needs and, consequently,...
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Mechatronic design o strongly nonlinear systems on a basis of three wheeled mobile platform
PublicationRemarkable grow in demand both of mobile platform operability performance and reduction of project leading time development encourage to apply modern algorithms and reliable engineering tools for the design process. The paper discusses the mechatronic design applied for the surveillance system based on the energy performance index algorithm. The exploited mechatronic techniques i.e. virtual prototyping, Hardware-In-the-Loop Simulation...
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Hierarchical predictive control of integrated wastewater treatment systems
PublicationThe paper proposes an approach to designing the control structure and algorithms for optimising control of integrated wastewater treatment plant-sewer systems (IWWTS) under a full range of disturbance inputs. The optimised control of IWWTS allows for significant cost savings, fulfilling the effluent discharge limits over a long period and maintaining the system in sustainable operation. Due to the specific features of a wastewater...
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Quality Aspects in Digital Broadcasting and Webcasting Systems: Bitrate versus Loudness
PublicationIn this paper the quality aspects of bitrate and loudness in digital broadcasting and webcasting systems are examined. The authors discuss a survey concerning user preferences related with processing and managing audio content. The coding efficiency of a popular audio format is analyzed in the context of storing media. An objective study on a representative group of signal samples, as well as a subjective study of the perceived...
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SYSTEMS. JOURNAL OF TRANSDISCIPLINARY SYSTEMS SCIENCE
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Asynchronous Networked Estimation System for Continuous Time Stochastic Processes
PublicationIn this paper we examine an asynchronous networked estimation system for state estimation of continuous time stochastic processes. Such a system is comprised of several estimation nodes connected using a possibly incomplete communication graph. Each of the nodes uses a Kalman filter algorithm and data from a local sensor to compute local state estimates of the process under observation. It also performs data fusion of local estimates...