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Search results for: chatter damping
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Four-stroke engine with central located, dyvided combustion chamber
PublicationW artykule przedstawiono oryginalne rozwiązanie konstrukcyjne nowoczesnego czterosuwowego silnika spalinowego z centralnie umieszczoną, dzieloną komorą spalania. Rozwiązanie takie umożliwia znacznie lepsze wykorzystanie ciepła, co oznacza wyższą sprawność i mniejsze zużycie paliwa oraz niższą emisję szkodliwych gazów takich, jak tlenki azotu (NO2), węglowodory (HC) i dwutlenek węgla (CO2). Silnik może pracować na paliwo płynne...
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Porous structures in aspects of transpirating cooling of oxycombustion chamber walls
PublicationA wet oxycombustion chamber, which must be effectively cooled due to high temperature evolved during the oxy-combustion process, by using the phenomena of Reynolds thermal transpiration and Navier slip velocity. Closures needed to execute mass flow rate in a microchannel, which should be treated as a single porous structure in the walls of the combustion chamber, have been obtained by applying a local 3D approach. The Navier-Stokes...
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Fast clutter cancellation for noise radars via waveform design
PublicationCanceling clutter is an important, but very expensive part of signal processing in noise radars. It is shown that considerable improvements can be made to a simple least squares canceler if minor constraints are imposed onto noise waveform. Using a combination of FPGA and CPU, the proposed scheme is capable of canceling both stationary clutter and moving targets in real-time, even for high sampling rates.
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Architecture Design of a Networked Music Performance Platform for a Chamber Choir
PublicationThis paper describes an architecture design process for Networked Music Performance (NMP) platform for medium-sized conducted music ensembles, based on remote rehearsals of Academic Choir of Gdańsk University of Technology. The issues of real-time remote communication, in-person music performance, and NMP are described. Three iterative steps defining and extending the architecture of the NMP platform with additional features to...
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Koncepcja poprawy jakości docierania elementów cienkościennych na docierarce jednotarczowej = Conception of quality improvement of thin-walled elements lapping done on single-disk lapping machine
PublicationPrzedstawiono problem zapewnienia prawidłowych warunków współpracy przedmiotu obrabianego i narzędzia tarczowego w czasie docierania płaskich elementów cienkościennych. Omówiono sposób dociążania elementów podczas obróbki oraz wytrzymałościowy model układu.
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Badania jakości docierania stali hartowanej docierakami aktywizowanymi w sposób swobodny = Study of hardened steel lapping quality where lapping tools are activized in a free way
PublicationPrzedstawiono badania jakości docierania stali hartowanej docierakami zbrojonymi w sposób swobodny. Analizowano wpływ podstawowych warunków obróbki na chropowatość powierzchni obrobionej. Wyznaczono zależność parametru Ra od prędkości i czasu docierania oraz nacisku jednostkowego. Analizowano również zanieczyszczenie powierzchni ścierniwem po docieraniu.
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Efficient sampling of high-energy states by machine learning force fields
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Calibration of Passive Samplers for the Monitoring of Pharmaceuticals in Water-Sampling Rate Variation
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Evaluation of different warping methods for the analysis of CE profiles of urinary nucleosides
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Azo dyes: Sources, occurrence, toxicity, sampling, analysis, and their removal methods
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Characterisation of the interfacial heat transfer coefficient in hot stamping of titanium alloys
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Data Sampling-Based Feature Selection Framework for Software Defect Prediction
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LiDAR based urban vegetation mapping as a basis of green infrastructure planning
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Passive sampling as a tool for obtaining reliable analyticalinformation in environmental quality monitoring
PublicationSpośród technik pobierania próbek analitów technika dozymetrii pasywnej wydaje się być interesującą alternatywą w stosunku do powszechnie stosowanych technik dynamicznych. Dozymetria pasywna łączy w sobie etap pobierania próbki z etapem izolacji i wzbogacania analitów, które są zatrzymywane w odpowiednim medium zatrzymującym. Prowadzi to do znacznego uproszczenia operacji analitycznych wykonywanych in situ. W odróżnieniu od aktywnych...
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Application of dynamic time warping and cepstrograms to text-dependent speaker verification
PublicationThis work provides a description of an automatic speaker verification (ASV) system. In particular, it documents the evolution of all individual stages of the proposed ASV system design from the phase of preprocessing to an operational decision making system. The aim of this research was to achieve the system of the best safety and ease of use in view of users. The objective estimation of this target has been accomplished by assessing...
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An Approach to Imbalanced Data Classification Based on Instance Selection and Over-Sampling
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Learning from Imbalanced Data Using Over-Sampling and the Firefly Algorithm
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High Efficiency Configuration Space Sampling -- probing the distribution of available states
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Mapping the complexity of dementia: factors influencing cognitive function at the onset of dementia
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The influence of sampling parameters on accuracy of capacitance measurement in the method based on DSP.
PublicationW artykule przedstawiono metodę pomiaru parametrów impedancyjnych bazującą na próbkowaniu sygnałów pomiarowych i DSP. Przeanalizowano wpływ głównych źródeł niepewności i błędów na dokładność pomiaru pojemności. Zawarto analizę dla następujących parametrów: niesynchroniczne próbkowanie sygnałów pomiarowych (napięciowego i prądowego), rozdzielczość przetwornika a/c i ilość zbieranych próbek. Załączono wyniki symulacji.
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Mapping the spatial distribution of global anthropogenic mercury atmospheric emission inventories
PublicationW pracy przedstawiono procedury zastosowane do przygotowania map emisji rtęci ze źrodeł antropogennych na skale globalna i przedyskutowano wyniki obliczeń przedstawione na tych mapach. Dane o emisji użyte do przygotowania map zostały obliczone i opublikowane przez Pacyna et al. (2006). W niniejszej pracy przedstawiono mapy emsji dla roku 2000 oraz zmodyfikowane mapy emisji dla roku 1995.Mapy z rozkladem emisji w układzie gridów:...
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Surface roughness of ceramic parts after lapping by abrasive-metallic tools
PublicationPrzedstawiono konstrukcję narzędzi ścierno-metalowych do obróbki na docierarce jednotarczowej. Wykonano badania docierania elementów z ceramiki tlenowej. Analizowano podstawowe parametry chropowatości powierzchni elementów z Al2O3 po obróbce narzędziami na bazie węglika boru.
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Torsional buckling of thin walled I beam column with warping stiffeners.
Publication.
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From flow to jamming: Lattice Gas Automaton simulations in granular materials
PublicationWe introduce the first extension of a Lattice Gas Automaton (LGA) model to accurately replicate observed emergent phenomena in granular materials with a special focus on previously unexplored jamming transitions by incorporating gravitational effects, energy dissipation in particle collisions, and wall friction. We successfully reproduce flow rate evolution, density wave formation, and jamming transition observed in experiments....
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Abrasive property evaluation during microgrinding with single-disk lapping kinematics
PublicationPrzedstawiono wyniki badań mikroszliwowania z kinematyką docierania jednotarczowego. Analizowano narzędzie pod kątem trwałości. Wyznaczono zmieniające się właściwości ścierne narzędzia z wykorzystaniem systemu do automatycznej analizy obrazu.
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Probabilistic Analysis of Structure Models using Target Random Sampling (TRS)
PublicationThe work presents testing methods of sensitivity and reliability of mechanical or structural systems. All computations concerned the case of Zigler column, a simple model of a compressed column involving two random variables only. A conclusion was drawn that the standard Monte Carlo method, its reduction variants and the response surface method allow to assess the sensitivity of structural response to the variation of random structural...
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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublicationData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Dynamic Headspace Sampling as an Initial Step for Sample Preparation in Chromatographic Analysis
PublicationThis work represents a brief summary of the use of dynamic headspace (DHS) as a technique for sample preparation in chromatographic analysis. Despite numerous developments in the area of analyte isolation and enrichment, DHS remains one of the fundamental methods used with GC. In our opinion, interest in this technique will not diminish significantly because it conforms to stipulations of green analytical chemistry. Moreover, DHS...
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Wideband Signal Generation for Jamming Radio-Controlled Improvised Explosive Devices
PublicationThis paper focuses on modelling operation of a wideband jamming signal generator, considering the effects present in real device which influence the shape of transmitted signal’s spectrum. Introduction is followed by a brief overview of AEGIS project, aim of which is to develop a mobile generator of electromagnetic curtain. Next, simulation model is described which includes the factors...
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Depth Determination Accuracy of the Modified Prony Method in a Swath Mapping Application
PublicationThis article presents the performance of the modified Prony method in a swath mapping application. Depth determination accuracy is assessed by processing raw signal acquired by an EdgeTech 6205 swath bathymetry system over flat seafloor. An updated version of the method, proposed previously by the authors, is used to determine the number of signal echoes. The number of signal echoes is essential for performing the low-rank approximation...
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The Influence of Workpiece Hardness on Plate Temperature during One Side Lapping
PublicationLapping leads to a surface with low roughness and high precision. Because of required parts accuracy tool flatness is the key to the successful machining. To avoid its excessive thermal expansion, plate temperature research was taken. The goal was to determine the correlation between the basic lapping conditions and wheel temperature. In work Bulsara et al. authors developed model to estimate the maximum and average temperature...
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The Effect of Circular Saw Blade Clamping Diameter on its Resonant Frequencies
PublicationIn this paper results of comparison of characteristic resonant frequencies of circular saw blades as a function of the saw clamping diameter from the impact test are presented. Obtained results revealed that proportionally with the increase of the saw clamping diameter also the dynamical stiffness of the saw blade increased. As a consequence of that the resonant frequencies of the saw blade move to higher values. Moreover, with...
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Three-dimensional mapping for data collected using variable stereo baseline
PublicationThe paper describes a system of 3D mapping of data collected with due regard for variable baseline. This solution constitute an extension to a VisRobot sub-system developed as a subsystem, necessary for implementing the generic idea of using mobile robots to explore an indoor static environment. This subsystem is to acquire stereo images, calculate the depth in the images and construct the sought 3D map. Stereo images are obtained...
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An automated microwave planar filter design based on space mapping optimization
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Characterization of PLZT Thin Films for Fast Electro-Optical Sampling Circuits
PublicationW artykule omówiono technologię wytwarzania cienkich warstw wybranych kompozycji ceramik ołowiowo-lantanowo-cyrkonowo-tytanowych, nazywanych ceramikami PLZT. Przedstawiono wyniki badań jakości warstw za pomocą techniki XRD. wyniki pomiaru grubości warstw, ich względnej przenikalności dielektrycznej i współczynnika załamania. Omówiono kierunki dalszych prac.
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Soxhlet Extraction and New Developments Such as Soxtec in: Comprehansive Sampling and Sample Preparation
PublicationSoxhlet extraction is one of the most popular techniques for extraction of analytes from solid materials. Since its discovery in 1879, the standard Soxhlet technique has been routinely applied in almost every analytical laboratory. Up to this day, Soxhlet extraction technique remains a standard technique to which the performance of modern extraction techniques is compared.Over the years, an intensive research on different modifications...
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Validation and Regulatory Issues for Sample Preparation in: Comprehensive Sampling and Sample Preparation
PublicationW rozdziale opisano podstawowe terminy związane z walidacja procedury analitycznej. Szczególnie zwrócono uwagę na etapy pobierania i przygotowania próbek do analizy. Podano także rolę i znaczenie poszczególnych składowych procesu kontroli i zapewnienia jakości wyników pomiarów analitycznych.
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New kinematic systems in single-sided lapping and their influence on lap wear
PublicationPrevious studies on one-sided lapping allow to state that not only parameters of lapping elements (i.e. properties of workpiece, abrasive grains and lapping plate) impact on a lapping efficiency. Influential are also kinematics and dynamics of the process. It is crucial to control an average velocity of lapping (v), a distribution of tangential acceleration (at), a nominal pressure (p), a lapping time (t) and disposal of workpiece...
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Substrate-integrated waveguide (SIW) filter design using space mapping
PublicationIn this paper, we present a fast technique for an automated design of microwave filters in substrate integrated wave (SIW) technology. The proposed methodology combines the space mapping technique with a cost function defined using the location of complex zeros and poles of filter’s transfer and reflection function and uses a rectangular waveguide as a surrogate model. The effectiveness of the proposed technique is presented with...
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The effect of circular saw blade clamping diameter on its resonant frequencies
PublicationIn this paper results of comparison of characteristic resonant frequencies of circular saw blades as a function of saw clamping diameter from the impact test are presented. Obtained results revealed that proportionally with the increase of the saw clamping diameter also the dynamical stiffness of the saw blade increased. As a consequence of that the resonant frequencies of the saw blade move to higher values. Moreover, with the...
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Mapping negative unintended consequences of disruptive technologies use in smart cities
PublicationSmart cities governance (SCG) consists of both to foster technology-enabled innovation, and to utilize disruptive technologies (DT) outcomes and impacts to increase public value of urban services. Despite widespread discussion of DT benefits, scientific literature identifies multiple determinants of unintended negative consequences (UC) of DT deployment in smart city initiatives. By considering UC as the negative aspects resulting...
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Magnetic field mapping along a NV-rich nanodiamond-doped fiber
PublicationIntegration of NV−-rich diamond with optical fibers enables guiding quantum information on the spin state of the NV− color center. Diamond-functionalized optical fiber sensors have been demonstrated with impressive sub-nanotesla magnetic field sensitivities over localized magnetic field sources, but their potential for distributed sensing remains unexplored. The volumetric incorporation of diamonds into the optical fiber core allows...
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Numerical simulation of a thin-walled beam with warping stiffeners undergoing torsion
PublicationW pracy rozwinięto koncepcję zastosowania superelementów węzłowych do modelowania stężeń konstrukcyjnych w belkach cienkościennych. Przeprowadzono analizę pracy belek cienkościennych o bisymetrycznym przekroju otwartym ze stężeniami bimomentowymi w formie przepon i przewiązek.
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Efficient uncertainty quantification using sequential sampling-based neural networks
PublicationUncertainty quantification (UQ) of an engineered system involves the identification of uncertainties, modeling of the uncertainties, and the forward propagation of the uncertainties through a system analysis model. In this work, a novel surrogate-based forward propagation algorithm for UQ is proposed. The proposed algorithm is a new and unique extension of the recent efficient global optimization using neural network (NN)-based...
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Constrained aerodynamic shape optimization using neural networks and sequential sampling
PublicationAerodynamic shape optimization (ASO) involves computational fluid dynamics (CFD)-based search for an optimal aerodynamic shape such as airfoils and wings. Gradient-based optimization (GBO) with adjoints can be used efficiently to solve ASO problems with many design variables, but problems with many constraints can still be challenging. The recently created efficient global optimization algorithm with neural network (NN)-based prediction...
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Introduction to smart solutions for wastewater: Road-mapping the transition to circular economy
PublicationToday there is an urgent need to move from a linear to a circular economy approach with special focus to water and environment. Despite the paramount importance, this transition is hampered by barriers which concern not only technological but embrace also organizational, regulatory, social, and economic aspects. In order to overcome such barriers, innovative water-smart solutions are needed and a robust roadmap for the transition...
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Landscape of Automated Log Analysis: A Systematic Literature Review and Mapping Study
PublicationLogging is a common practice in software engineering to provide insights into working systems. The main uses of log files have always been failure identification and root cause analysis. In recent years, novel applications of logging have emerged that benefit from automated analysis of log files, for example, real-time monitoring of system health, understanding users’ behavior, and extracting domain knowledge. Although nearly every...
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Improved jamming resistance using electronically steerable parasitic antenna radiator
PublicationThis paper presents an idea of using an Electronically Steerable Parasitic Antenna Radiator (ESPAR) for jamming suppression in IEEE 802.11b networks. Jamming (intentional interference) attacks are known to be effective and easy to perform, which may impose connectivity problems in applications concerning Internet of Things (IoT). In our paper, theoretical considerations are presented and the results of experiments performed in...
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Gas selectivity enhancement by sampling-and-hold method in resistive gas sensors
PublicationCommercial resistive gas sensors exhibit various sensitivity to numerous gases when working at different elevated temperatures. That effect is due to a change in velocity of adsorption and desorption processes which can be modulated by temperature. Thus, to reach better selectivity of gas detection, we propose to apply a known method (called the sampling-and-hold method) of cooling down the gas sensor in the presence of the investigated...
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Chapter 34. Influence of salt on micellisation of 1-decyl-3-methyl imidazolium chloride in aqueous solution
PublicationZbadano wpływ prostych elektrolitów na micelizację chlorku 1-decylo-3-metyloimidazoliowego w środowisku wodnym. Zaobserwowano, że dodatek soli powoduje obniżanie krytycznego stężenia micelizacji (CMC) badanego związku z siłą zgodną z trendem opisanym szeregiem Hofmeistera. Przedstawiono również zależność między stężeniem dodanej soli a CMC.