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Search results for: time-frequency domain
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Finding small-width connected path decompositions in polynomial time
PublicationA connected path decomposition of a simple graph $G$ is a path decomposition $(X_1,\ldots,X_l)$ such that the subgraph of $G$ induced by $X_1\cup\cdots\cup X_i$ is connected for each $i\in\{1,\ldots,l\}$. The connected pathwidth of $G$ is then the minimum width over all connected path decompositions of $G$. We prove that for each fixed $k$, the connected pathwidth of any input graph can be computed in polynomial-time. This answers...
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Frequency of use, moral incongruence, and religiosity and their relationships with self-perceived addiction to pornography, internet use, social networking and online gaming
PublicationBackground and Aims Moral incongruence involves disapproval of a behaviour in which people engage despite their moral beliefs. Although considerable research has been conducted on how moral incongruence relates to pornography use, potential roles for moral incongruence in other putative behavioural addictions have not been investigated. The aim of this study was to investigate the role of moral incongruence in self‐perceived...
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Numerical Analysis of Recharge Rates and Contaminant Travel Time in Layered Unsaturated Soils
PublicationThis study focused on the estimation of groundwater recharge rates and travel time of conservative contaminants between ground surface and aquifer. Numerical simulations of transient water flow and solute transport were performed using the SWAP computer program for 10 layered soil profiles, composed of materials ranging from gravel to clay. In particular, sensitivity of the results to the thickness and position of weakly permeable...
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Coupled-Resonator Waveguide Filter in Quadruplet Topology With Frequency-Dependent Coupling - A Design Based on Coupling Matrix
PublicationThis letter presents an application of a recently developed coupling matrix synthesis technique to design of coupled-resonator filters with dispersive inter-resonator couplings. This technique is used to design a novel coupled-cavity bandpass filter. Measurements validate the design and confirm effectiveness of the synthesis method. The filter is a four-pole generalized Chebyshev filter with three transmission zeros. Resonators...
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A Trisection Filter Design With Negative Slope of Frequency-Dependent Crosscoupling Implemented in Substrate Integrated Waveguide (SIW)
PublicationThis letter reports on a novel realization of a microwave bandpass filter in a triplet configuration with a frequency-dependent crosscoupling implemented in substrate integrated waveguide (SIW). The design involves implementing dispersive coupling with a negative slope, a feature that allows the capabilities of the classic triplet topology to be extended. In this particular case, the implementation of two transmission zeros on...
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Modeling the effect of parasitic capacitances on the dead-time distortion in multilevel NPC inverters
PublicationA simple model is derived and verified for evaluating the effect of parasitic capacitances on the dead-time related voltage distortion in multilevel NPC voltage source inverters. The model permits well-defined and precise compensation of dead-time distortion, exhibiting meaningful improvement on compensation methods neglecting the effects of parasitic capacitances. A simple formula is given for evaluating the capacitances as serial/parallel...
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Globalized Knowledge-Based Simulation-Driven Antenna Miniaturization Using Domain-Confined Surrogates and Dimensionality Reduction
PublicationDesign of contemporary antenna systems encounters multifold challenges, one of which is a limited size. Compact antennas are indispensable for the new fields of application such as inter-net of things or 5G/6G mobile communication. Still, miniaturization generally undermines elec-trical and field performance. When attempted through numerical optimization, it turns into a constrained problem with costly constraints requiring electromagnetic...
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Editorial for the special issue on advances in forward and inverse surrogate modeling for high-frequency design
PublicationThe design of modern‐day high‐frequency devices and circuits, including microwave/RF, antenna and photonic components, historically has relied on full‐wave electromagnetic (EM) simulation tools. Initially used for design verification, EM simulations are nowadays used in the design process itself, for example, for finding optimum values of geometry and/or material parameters of the structures of interest. In a growing number of...
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Cross-Platform Real-Time Nuclear Reactor Basic Principle Simulator
PublicationAbstract—In the paper several approaches to building the real-time basic principle simulators of nuclear reactor processes are presented and their characteristics are analyzed. The characteristics of developed simulators for MATLAB/Simulink including their limitations, and the idea of a cross-platform simulator independent of specific hardware or software are presented. Mathematical models of selected nuclear reactor’s processes...
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An Overview of the Development of a Real-Time System for Endoscopic Video Classification
PublicationThe article presents the results of improving endoscopic image classification algorithms in an effort towards applying them in a real-time diagnosis supporting system. Methods for the detection and removal of personal data are presented and discussed. The currently developed recognition algorithms have been improved in terms of accuracy and performance to make them suitable for a real-life implementation. Their test results are...
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Real-time hybrid model of a wind turbine with doubly fed induction generator
PublicationIn recent years renewable sources have been dominating power system. The share of wind power in energy production increases year by year, which meets the need to protect the environment. Possibility of conducting, not only computer simulation, but also laboratory studies of wind turbine operation and impact on the power system and other power devices in laboratory conditions would be very useful. This article presents a method...
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CRUNCH Time na 17 Biennale Architektury w Wenecji, w Pawilonie Włoskim
Publicationhttps://arch.pg.edu.pl/strona-glowna/wydarzenia/crunch-time-na-biennale-architektury-w-wenecji-2021 https://pg.edu.pl/aktualnosci/2021-10/sukces-gdanskich-urbanistow-crunch-time-na-biennale-architektury-w-wenecji
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Formulation of Time-Fractional Electrodynamics Based on Riemann-Silberstein Vector
PublicationIn this paper, the formulation of time-fractional (TF) electrodynamics is derived based on the Riemann-Silberstein (RS) vector. With the use of this vector and fractional-order derivatives, one can write TF Maxwell’s equations in a compact form, which allows for modelling of energy dissipation and dynamics of electromagnetic systems with memory. Therefore, we formulate TF Maxwell’s equations using the RS vector and analyse their...
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Low cost real time UAV stereo photogrammetry modelling technique – accuracy considerations
PublicationThe paper presents accuracy considerations regarding three 3D modelling techniques. The tested new consumer type stereo camera (ZED 3D Stereolabs) has been implemented info an aerial mapping system, on board micro air vehicle MAV) and tested object has been mapped using a real-time photogrammetry with original real-time software application. The evaluated results has been compared with model gained with a state of art unmanned...
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Thermal heat-balance mode flow-to-frequency converter
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Digital measurement of frequency with linear interpolation in dynamic states
PublicationPrzedstawiono metody rejestracji częstotliwości sygnałów impulsowych. Zastosowanie interpolacji pozwala na uzyskanie wyniku dla dowolnej chwili. Opisano pracę w trybie on-line i off-line.
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Impedance matching in dual-frequency induction heating systems
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On the use of instantaneous complex frequency for pitch and formant tracking.
PublicationW pracy opisano algorytm śledzenia częstotliwości podstawowej i formantów mowy z wykorzystaniem zespolonej pulsacji chwilowej. Działanie algorytmu przetestowano na nagraniach polskich samogłosek, których wysokość zmieniała się płynnie. Wyniki testów wraz z porównaniem działania opisanej metody i metody predykcji liniowej zawarto w artykule.
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Frequency dispersion of harmonic components of the current of an electrode process
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Online pitch estimation using instantaneous complex frequency
PublicationW pracy opisano nowe wyniki dotyczące skuteczności algorytmu potokowego estymującego częstotliwość podstawową sygnału mowy. Algorytm wykorzystuje zespoloną pulsację chwilową dla klasyfikacji mowy na dźwięczną i bezdźwięczną oraz estymacji częstotliwości podstawowej dla każdej próbki sygnału. Skuteczność klasyfikacji oraz dokładność estymacji zostały ocenione eksperymentalnie z wykorzystaniem dwóch baz nagrań, zawierających wypowiedzi...
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Impulse and high frequency methods of lighting earthing testes.
PublicationUziemienia projektowane dla prądów zwarciowych nie zawsze są właściwe do odprowadzania prądów piorunowych, gdzie należy brać pod uwagę impedancję uziemień. W pracy porównano metody: udarową oraz wysokiej częstotliwości zastosowane do oceny przydatności uziemień odgromowych.
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Automated design of waveguide filters with frequency-dependent couplings.
PublicationW artykule zaproponowano szybką technikę pozwalającą na automatyczne projektowanie filtrów falowodowych ze sprzężeniami zależnymi od częstotliwości. Procedura optymalizacyjna jest trójetapowa z różnymi funkcjami celu w każdym etapie.
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Corrosion monitoring by frequency intermodulation technique employing Gabortransformation
PublicationMonitorowano proces korozji zachodzący na stali ST3S w środowisku obojętnym. Wykonane zostały badania harmoniczne techniką intermodulacji częstotliwościowej. W analizie harmonicznej zastosowana została nowa metoda czasowo-częstotliwościowej tzw. transformacji Gabora. Wykazane zostało, że transformacja Gabora może być przydatna w monitorowaniu korozji w warunkach dynamicznych. Transformacja Gabora pozwala na dobrą reprezentację...
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Voltage and frequency regulation of a standalone induction generator by reduced-rating power electronic compensators - comparative evaluation
PublicationIn this paper are considered two fundamental topologies of power electronic compensators for voltage and frequency control of a standalone self-excited induction generator (IG) system. These are voltage and current source inverter based shunt compensators with energy storage. The aim of this study is to assess main features of both topologies in dynamic and steady-state IG operation. The whole system is modelled with the aid of...
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Asynchronous distributed state estimation for continuous-time stochastic processes
PublicationWe consider the problem of state estimation of a continuous-time stochastic process using an asynchronous distributed multi-sensor estimation system (ADES). In an ADES the state of a process of interest is estimated by a group of local estimators. Each local estimator based, for example, on a Kalman filter, performs single sensor filtration but also fusion of its local results and results from other (remote) processors to compute...
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Prediction of Processor Utilization for Real-Time Multimedia Stream Processing Tasks
PublicationUtilization of MPUs in a computing cluster node for multimedia stream processing is considered. Non-linear increase of processor utilization is described and a related class of algorithms for multimedia real-time processing tasks is defined. For such conditions, experiments measuring the processor utilization and output data loss were proposed and their results presented. A new formula for prediction of utilization was proposed...
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RSS-Based DoA Estimation in 802.11p Frequency Band Using ESPAR Antenna and PPCC-MCP Method
PublicationIn this paper, the concept of direction of arrival (DoA) estimation using electronically steerable parasitic array radiator (ESPAR) antenna designed to operate in IEEE 802.11p vehicular communication standard has been investigated with respect to different possible elevation angles of a radio frequency (RF) signal impinging the antenna. To this end, two different possible sets of the 3D antenna radiation patterns have been used...
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Static Shape and Stress Control of Trusses with Optimum Time, Actuators and Actuation
PublicationTraditional shape and stress control of structures use many actuators and require enormous time to find reasonable solutions that need designers to input specific target displacement and stress. This study employs a linear technique to static shape and stress control of pin-jointed assemblies as a theoretical advancement to prior works and provides a comparative analysis against previously established works. The study evaluates...
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Investigating the Impact of Weather Conditions and Time of Day on Traffic Flow Characteristics
PublicationAdverse weather such as rain, snow, and fog may significantly reduce visibility or change adhesion properties and, as a consequence, affect drivers’ sense of safety, driving comfort, and their reaction to a changing driving environment (i.e., lower speed and increased headways). The changed behavior of individual drivers affects both traffic flow characteristics, that is, average speed and headways, and parameters related to highway...
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Characterization of Corrosion-Induced Fracture in Reinforced Concrete Beams Using Electrical Potential, Ultrasound and Low-Frequency Vibration
PublicationThe paper deals with the non-destructive experimental testing of the reinforced concrete beams under progressive corrosion. A series of experiments using electrical potential, ultrasound and low-frequency vibrations techniques are reported. Electrical potential and natural frequencies were used to characterise and monitor the corrosion process at its initial state. The P-wave velocity measurements were proved to be effective in...
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Adaptive identification of sparse underwater acoustic channels with a mix of static and time-varying parameters
PublicationWe consider identification of sparse linear systems with a mix of static and time-varying parameters. Such systems are typical in underwater acoustics (UWA), for instance, in applications requiring identi- fication of the acoustic channel, such as UWA communications, navigation and continuous-wave sonar. The recently proposed fast local basis function (fLBF) algorithm provides high performance when identi- fying time-varying systems....
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Selected local stability problems of channel section flanges made of aluminium alloys
PublicationThe paper addresses the issue of local buckling of compressed flanges of cold-formed thin-walled channel columns and beams with nonstandard flanges composed of aluminium alloys. The material behaviour follows the Ramberg–Osgood law. It should be noted that the proposed solution may be also applied for other materials, for example: stainless steel, carbon steel. The paper is motivated by an increasing interest in nonstandard cold-formed...
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Analysis of IMS/NGN Call Processing Performance Using Phase-Type Distributions Based on Experimental Histograms
PublicationThe paper describes our further research done with the proposed analytical and simulation traffic models of the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). The aim of our models of a single IMS/NGN domain is to evaluate two standardized call processing performance parameters, which appropriate values are very...
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Analysis of IMS/NGN call processing performance using phase-type distributions
PublicationThis work is a continuation of our research on the traffic model dedicated for design and analysis of the Next Generation Network (NGN), which is standardized for distribution of current and future multimedia services based on the IP Multimedia Subsystem (IMS). Our analytical and simulation models allow evaluation of mean Call Set-up Delay E(CSD) as well as mean Call Disengagement Delay E(CDD) in a single domain of IMS/NGN. Ensuring...
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Texture or Linker? Competitive Patterning of Receptor Assembly toward Ultra-Sensitive Impedimetric Detection of Viral Species at Gold-Nanotextured Titanium Surfaces
PublicationIn this work, we study the electrodes with a periodic matrix of gold particles pattered by titanium dimples and modified by 3-mercaptopropionic acid (MPA) followed by CD147 receptor grafting for specific impedimetric detection of SARS-CoV-2 viral spike proteins. The synergistic DFT and MM/MD modeling revealed that MPA adsorption geometries on the Au–Ti surface have preferential and stronger binding patterns through the carboxyl...
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Simulation-Driven Antenna Modeling by Means of Response Features and Confined Domains of Reduced Dimensionality
PublicationIn recent years, the employment of full-wave electromagnetic (EM) simulation tools has become imperative in the antenna design mainly for reliability reasons. While the CPU cost of a single simulation is rarely an issue, the computational overhead associated with EM-driven tasks that require massive EM analyses may become a serious bottleneck. A widely used approach to lessen this cost is the employment of surrogate models, especially...
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Neural network training with limited precision and asymmetric exponent
PublicationAlong with an extremely increasing number of mobile devices, sensors and other smart utilities, an unprecedented growth of data can be observed in today’s world. In order to address multiple challenges facing the big data domain, machine learning techniques are often leveraged for data analysis, filtering and classification. Wide usage of artificial intelligence with large amounts of data creates growing demand not only for storage...
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Business continuity management framework for Industry 4.0 companies regarding dependability and security of the ICT and ICS/SCADA system
PublicationThis chapter addresses a business continuity management (BCM) framework for the Industry 4.0 companies including the organizational and technical solutions, regarding the dependability and security of the information and telecommunication technology (ICT), and the industrial control system (ICS) / supervisory control and data acquisition (SCADA) system. These technologies and systems play nowadays important roles in modern advanced...
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The youth in polish legations and government
PublicationUntil the 2015 elections, youth policy in Poland was treated as a separate domain. There is no uniform legal basis concerned with the matters of young people. Youth rights are dealt with in several articles of the Constitution of the Republic of Poland as well as a number of Acts: on Public Administration Branches, on the Education System, on Higher Education, on Employment Promotion and Labour Market Institutions, on NFZ General...
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Road safety analysis in Poland using time-series modelling techniques
PublicationA number of international studies argue that there is a correlation between the number of traffic fatalities and the degree of public activity. The studies use the unemployment rate to support that argument. As unemployment grows miles travelled fall, a factor known to affect road safety. This relationship seems to be true for Poland, as well. The model presented in the paper is intended to prove it. It is a structural time-series local...
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Recovery of Anammox Biomass at Short Hydraulic Retention Time in a MBR Reactor
PublicationThe anammox system has been consider as an economical option for treating high concentration of nitrogen and poor in biodegradable orgaednic carbon wastewaters. This process is attractive option compared with conventional nitrogen removal because it provides a significant saving in aeration and organic addition for denitrification. The anammox technology has been applied mostly for concentrated nitrogenous wastewater containing...
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On the Handling of Outliers in the GNSS Time Series by Means of the Noise and Probability Analysis
PublicationThe data pre-analysis plays a significant role in the noise determination. The most important issue is to find an optimum criterion for outliers removal, since their existence can affect any further analysis. The noises in the GNSS time series are characterized by spectral index and amplitudes that can be determined with a few different methods. In this research, the Maximum Likelihood Estimation (MLE) was used. The noise amplitudes...
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Time and clock synchronization with AFCK for CBM
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Time evolution of luminescence of Sr2SiO4:Eu2+
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Hazard prevention by forced time constraints
PublicationMinimalne Zbiory Przyczyn powstałe podczas analizy Drzew Błędów wskazują zdarzenia, które jeśli nastąpią razem, mogą doprowadzić do Hazardu. W niektórych zastosowaniach opis zdarzeń może zostać poszerzony o informację czasową, wtedy zdarzenia z MZP mogą doprowadzić do Hazardu tylko jeśli wystąpi pomiędzy nimi określona zależność czasowa. W tym artykule przedstawione zostało jak informacja czasowa może zostać wprowadzona do Drzew...
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Dichotomous design of real-time systems
PublicationW pracy prezentuje się i analizuje dwie podstawowe metody projektowania komputerowych systemów czasu rzeczywistego, spełniających rozmaite zadania z zakresu automatyki, sterowania, nadzoru i diagnostyki, w których następuje interakcja komputera z obiektami i procesami przemysłowymi, które posiadają naturę ciągłą (pozwalającą na ścisłą matematyczną charakteryzację w czasie ciągłym). Definiuje się podejście uwarunkowane kontekstowo...
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TreeCmp: Comparison of Trees in Polynomial Time
PublicationMetryki filogenetyczne umożliwiają ocenę jakości wyników analizy filogenetycznej oraz wiarygodności algorytmów przeprowadzających taką analizę. Aplikacja TreeCmp oferuje efektywne, wielomianowe implementacje ośmiu takich metryk (dla drzew nieukorzenionych i zawierających korzeń) zdefiniowanych dla dowolnych filogenez (nie koniecznie binarnych). Program ten jako pierwszy umożliwia wyznaczanie nowych metryk, definiowanych w oparciu...
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Hypertension and sexual dysfunction: time to act
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Time-of-flight spectroscopy for medical applications.
PublicationW pracy przedstawiono korzyści optycznej spektroskopii czasu przelotu, w zastosowaniach medycznych. Przedstawiono także zasadę pomiarów oraz pokazano, jak z danych pomiarowych można wyznaczyć podstawowe parametry optyczne tkanki. Potencjał pomiarowy optycznej spektroskopii czasu przelotu zaprezentowano na przykładzie pomiarów ośrodków silnie rozpraszających światło jakimi są: papier, cicze technologiczne z papierni, wodne roztwory...
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Differential inequalities with initial time difference.
PublicationUzyskano pewne wyniki porównawcze pomiędzy rozwiązaniami nierówności różniczkowych startujących z różnych punktów początkowych. O nieliniowej funkcji f (związanej z zagadnieniem) zakładano jednostronny warunek Lipschitza. Podano pewne zastosowanie otrzymanych wyników. Sformułowano też pewne warunki dotyczące stabilności.