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Search results for: brownian motion
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Analiza i realizacja sterowania serwonapędami w trzech osiach przez sterownik programowalny z wykorzystaniem opisu zadania poprzez G-KOD
PublicationObrabiarki sterowane komputerowo są obecnie powszechnie wykorzystywane w zautomatyzowanych procesach produkcji. Zadania realizowane przez te obrabiarki są najczęściej opisywane z wykorzystaniem G-kodu. W przypadku, gdy potrzebna jest realizacja jedynie podstawowych funkcji obrabiarki, a do takich należy realizacja ruchu narzędzia, nie zawsze istnieje potrzeba stosowania obrabiarek. Podstawowe funkcje sterowania z powodzeniem mogą...
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Modelowanie układu napędowego z przełączalnym silnikiem reluktancyjnym
PublicationW pracy zaprezentowano sposób modelowania przełączalnego silnika reluktancyjnego wraz z całym układem napędowym. Przełączalne silniki reluktancyjne, w odróżnieniu od silników innych typów, wymagają zasilania z przekształtnika energoelektronicznego wraz z systemem sterowania. Dla analiz symulacyjnych pełnego układu jest pożądane dysponowanie modelem obwodowym przełączalnego silnika reluktancyjnego. Obwodowy model silnika jest szczególnie...
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The wave character of commutator wear in electrical machines
PublicationW pracy przedstawiono wyniki badań doświadczalnych zużycia elementów ze styku ślizgowego silnika komutatorowego prądu przemiennego małej mocy. Zakres badań obejmował okresowe pomiary profilu powierzchni ślizgowej komutatora w przekroju poprzecznym oraz profilu powierzchni wycinków komutatora w przekroju podłużnym względem osi wirowania. Ponadto zmierzono okresowe wielkości zużycia powierzchni ślizgowej komutatora oraz szczotek...
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Symulator Sym-PS4 sterownika programowalnego PS4-201-MM1
PublicationW pracy przedstawiono opis opracowanego programowego symulatora Sym-PS4 sterownika programowalnego PS4-201-MM1. Symulator umożliwia tworzenie i testowanie programów sterowania napisanych dla samego sterownika, jak również programów napisanych dla sterownika z dołączonymi do niego modułami rozszerzenia lokalnego LE4. Symulator posiada możliwość dołączania do niego tworzonych modeli sterowanych obiektów i pozwala na symulację działania...
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2D Mathematical Model of the Commutator Sliding Contact of an Electrical Machine
PublicationW artykule przedstawiono model matematyczny 2D komutatorowego zestyku ślizgowego z wieloma stopniami swobody. W modelu uwzględniono zmienne wymuszenia działające na szczotkę. Wymuszenia te są wynikiem falistości wirującego komutatora. Szczotka została zamodelowana jako system wielu mas, elementów sprężystych i tłumików rozłożonych w kierunku stycznym i promieniowym. Zamodelowano wszystkie oddziaływania lepkosprężyste pomiędzy komutatorem...
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Nowoczesny system sterowania układem samoczynnego załączania rezerwy zasilania
PublicationW artykule, dla przykładu układu samoczynnego załączania rezerwy (SZR) zasilania o zadanej strukturze i diagramie łączeń, przedstawiono nowoczesny system sterowania tym układem SZR. Omówiono algorytm i program sterowania oraz wizualizację działania układu. Program sterowania i wizualizację opracowano w oprogramowaniu narzędziowym easy Soft CoDeSys ver.2.3.5.8. Przejrzystą strukturę programu sterowania osiągnięto dzięki opracowaniu...
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Algorytm i program sterowania układem samoczynnego załączania rezerwy zasilania z funkcją odciążania
PublicationW artykule omówiono układ samoczynnego załączania rezerwy (SZR) zasilania z jednym transformatorem i jednym generatorem przy rezerwie jawnej, z ośmioma grupami odbiorów i funkcją odciążania. W systemie sterowania tego układu SZR założono wykorzystanie sterownika programowalnego, graficznego dotykowego panelu operatorskiego i analizatorów parametrów sieci. Funkcja odciążania służy do realizacji przełączania wyłączników grup odbiorów...
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Improved performance of LaNi0.6Fe0.4O3 solid oxide fuel cell cathode by application of a thin interface cathode functional layer
PublicationIn this work, novel functional layers were prepared by a low temperature spray pyrolysis method on the oxygen side of the solid oxide cells. Thin layers of Ce0.8Gd0.2O2 and LaNi0.6Fe0.4O3 are prepared between the electrolyte and the porous oxygen electrode. Additionally the influence of the sprayed ceria barrier layer on the zirconia based electrolyte with the new layers is evaluated. Impedance spectroscopy results show improvement...
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Tlenkowe ogniwa paliwowe zbudowane na nośnym elemencie z metalowego porowatego interkonektora
PublicationW pracy przedtawiony stan rozwoju tlenkowych ogniw paliwowych zbudowanych na nośnym elemencie z metalowego porowatego interkonektora.
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Impact of the Alkyl Side Chains of Cations and Anions on the Activity and Renaturation of Lysozyme: A Systematic Study Performed Using Six Amino‐Acid‐Based Ionic Liquids
PublicationThe impact of the structure of ionic liquid on the activity and renaturation of lysozyme from the hen egg white (HEWL) was investigated. A set of six ionic liquids based on morpholinium cation and N-acylated amino acids as anions were exploited. The matrix used was based on two homologous series: one with N-acetyl-L-valinate [Val] as a common anion and morpholinium cation with a different number of carbon atoms in the n-alkyl chain...
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Be fearless: Positive affect as a mediator between venturesomeness and self-efficacy in future entrepreneurs and managers
PublicationIntroduction and objectives Self-efficacy, personality and different affect states in entrepreneurs and managers are important factors for effectiveness and well-being. The aim of the study was to examine in young adults during entrepreneurship-related education, the relationships between venturesomeness and self-efficacy, and the mediating effects of positive affect and positive emotions (joviality, self-assurance, attentiveness)...
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Telomerase inhibition - unfulfilled hopes in the perfect molecular target
PublicationTelomerase plays a pivotal role in cell proliferation, homeostasis, and neoplastic transformation, making it a promising molecular target for cancer chemotherapy. Of note, although hTERT has been explored thoroughly as a target, none of the promising molecules has been approved as a drug until now. The subject of research conducted as part of my doctoral dissertation is explaining the cellular and molecular mechanism of action...
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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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Niekorzystny wpływ przekształtnikowego zasilania PWM na silniki asynchroniczne trakcyjne
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
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Destructive impact of PWM inverters on traction AC motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings's increased voltage exposure and...
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Destructive Consequences of PWM Inverter Feeding for Traction AC Motors
PublicationThe electric traction drives with an AC motor fed by a frequency converter are used more and more often nowadays. The most significant side effects, of a converter's output voltage forming PWM method for AC motor windings, are steep voltage changes, which can initiate several destructive phenomena. The paper presents the adverse influence of a converter common mode voltage on the motor windings' increased voltage exposure and the...
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A Review of Reduction Methods of Impact of Common-Mode Voltage on Electric Drives.
PublicationIn this survey paper, typical solutions that focus on the reduction in negative effects resulting from the common-mode voltage influence in AC motor drive applications are re-examined. The critical effectiveness evaluation of the considered methods is based on experimental results of tests performed in a laboratory setup with an induction machine fed by an inverter. The capacity of a common-mode voltage level reduction and voltage...
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Vibro-Electrical Behavior of a Viscoelastic Piezo-Nanowire in an Elastic Substrate Considering Stress Nonlocality and Microstructural Size-Dependent Effects
PublicationThis research deals with dynamics response of a Pol/BaTiO3 nanowire including viscosity influences. The wire is also impressed by a longitudinal electric field. Hamilton's principle and Lagrangian strains are employed in conjunction with a refined higher-order beam theory in order to derive equations of motion. By combining nonlocality and small size...
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Wind Turbines Modeling as the Tool for Developing Algorithms of Processing their Video Recordings
PublicationIn the real world, many factors exist disturbing observation of the examined phenomena and causing various noises and distortions in recorded signals. It very often makes it difficult or even impossible to optimize various signal processing algorithms, through finding appropriate parameters. In this paper, we show an application, that retrieves wind turbine rotor speed from recorded video. Next, we describe the process of reduction...
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Experimental research on marine oil-lubricated stern tube bearing
PublicationBearings of propeller shafts are very crucial elements of the propulsion system of each of the ships. The safety of shipping depends on their durability and reliability. The new legal restrictions mean that today we are looking for environmentally friendly solutions. That is why water-lubricated bearings are becoming more and more popular. So, will oil-lubricated shaft bearings belong to the past? The bearing with a white metal...
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Wind Turbines Modeling as the Tool for Developing Algorithms of Processing their Video Recordings
PublicationIn the real world, many factors exist disturbing observation of the examined phenomena and causing various noises and distortions in recorded signals. It very often makes it difficult or even impossible to optimize various signal processing algorithms, through finding appropriate parameters. In this paper, we show an application, that retrieves wind turbine rotor speed from recorded video. Next, we describe the process of reduction...
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Instantaneous Heating and Cooling Caused by Periodic or Aperiodic Sound of Any Characteristic Duration in a Gas with Vibrational Relaxation
PublicationThermodynamic relaxation of internal degrees of a molecule's freedom in a gas occurs with some characteristic time. This makes wave processes in a gas behave differently depending on the ratio of characteristic duration of perturbations and the relaxation time. In particular, generation of the secondary non-wave modes by intense sound in a nonlinear flow dependens on frequency. These kinds of interaction are considered in this...
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Centrifugal magnetic fluid seals
PublicationSeals perform an important and at times overlooked function in a lubricant system. They prevent or minimize the movement of the lubricant between two surfaces and also minimize the level of contamination in the system. Seals are divided into static and dynamic types. Static seals operate in systems where the mating surfaces do not move relative to each other. In contrast, dynamic seals operate under conditions where the mating surfaces...
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Analysis of balancing of four stroke V6 engines
PublicationAnalysis of balance of V6 engines with a common-pin crankshaft depending on a cylinder bank angle and the crank radius to connecting rod length ratios , based on the relations derived, is presented in the paper. The bank angles providing the lowest moment of inertia forces in reciprocating motion, for selected values, were determined. The position of the plane of the main counterweights in order to maximum balance of the moment...
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Cyfrowy akcelerator wybranych modułów standardu kompresji wideo H.264
PublicationW komunikacie przedstawiono konfigurowalny cyfrowy akcelerator estymacji ruchu (motion estimation) przeznaczony dla enkodera wideo standardu H.264. Akcelerator został wstępnie zaimplementowany w układzie FPGA VIRTEX6-VLX365T, a następnie w układzie ASIC w technologii UMC 90 nm. Obie implementacje zostały zweryfikowane pozytywnie, a szczegółowe wyniki symulacji i pomiarów akceleratora ASIC zostały porównane z innymi dostępnymi w...
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Perspectives of Telematics Implementation in Tri-City Transport Systems Management and Planning
PublicationIn 2010 the City of Gdynia applied for match funding the project ''Implementation of the Integrated Traffic Management System TRISTAR in Tri-City" under the Operational Programme Infrastructure and Environment. This year the project has been placed on a list approved by the Ministry of Infrastructure. Tri-City proceeds with a tender for the implementation of the system. The project will be implemented in key elements are included...
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Response of high voltage disconnector under seismic excitation - experimental and numerical study
PublicationThe efficiency of the energetic infrastructure system is a very import safety issue in the region experienced by the ground motion. The aim of the present paper is to show the results of the experimental and numerical study focused on the earthquake-induced response of the high voltage disconnector, which is an important element of energetic network. First, the impact tests as well as the sweep-sine shaking table tests were conducted....
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Hand gesture recognition supported by fuzzy rules and Kalman filters
PublicationThe paper presents a system based on camera and multimediaprojector enabling a user to control computer applications by dynamic hand gestures. Gesture recognition methodology based on representing hand movement trajectory by motion vectors analysed using fuzzy rule-based inference is first given. For effective hand position tracking Kalman filters are employed. The system engineered is developed using J2SE and C++/OpenCV technology....
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Fading Modelling in Dynamic Off-Body Channels
PublicationThis paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components,...
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Autonomous Control of the Underwater Remotely Operated Vehicle in Collision Situation with Stationary Obstacle
PublicationThe article considers the problem of autonomous control of the underwater remotely operated vehicle mini Remotely Operated Vehicle (ROV) in a collision situation with a stationary obstacle. The control of the collision avoidance process is presented as a synthesis of fuzzy proportional-differential controllers for the control of distance and orientation concerning the detected stationary obstacle. The control of the submergence...
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Differential Quadrature Method for Dynamic Buckling of Graphene Sheet Coupled by a Viscoelastic Medium Using Neperian Frequency Based on Nonlocal Elasticity Theory
PublicationIn the present study, the dynamic buckling of the graphene sheet coupled by a viscoelastic matrix was studied. In light of the simplicity of Eringen's non-local continuum theory to considering the nanoscale influences, this theory was employed. Equations of motion and boundary conditions were obtained using Mindlin plate theory by taking nonlinear strains of von Kármán and Hamilton's principle into account. On the other hand, a...
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Leveraging spatio-temporal features for joint deblurring and segmentation of instruments in dental video microscopy
PublicationIn dentistry, microscopes have become indispensable optical devices for high-quality treatment and micro-invasive surgery, especially in the field of endodontics. Recent machine vision advances enable more advanced, real-time applications including but not limited to dental video deblurring and workflow analysis through relevant metadata obtained by instrument motion trajectories. To this end, the proposed work addresses dental...
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High-temperature oxidation of the Crofer 22 H ferritic steel with Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 spinel coatings under thermal cycling conditions and its properties
PublicationThe aim of the presented study was to deposit protective-conducting Mn1.45Co1.45Fe0.1O4 and Mn1.5Co1.5O4 spinel coatings on the Crofer 22 H ferritic steel by means of electrophoresis and to evaluate their physicochemical properties after high-temperature oxidation under thermal cycling conditions. When the Crofer 22 H steel – whether uncoated or coated with the two spinels – was oxidized in 48-h cycles involving a temperature of...
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High temperature oxidation behavior of SUS430 SOFC interconnects with Mn-Co spinel coating in air
PublicationIn this study, SUS430 alloy is evaluated for its high temperature corrosion properties as a possible material for interconnects of solid oxide fuel cells (SOFCs). Samples are coated with Mn-Co by commercial physical vapor deposition (PVD) process and oxidized in air for 1250 h at 800 °C. A dense cubic Mn-Co-Fe spinel layer is formed on the surface, showing great effect on corrosion reduction compared with the samples without coating....
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Badania stabilności chemicznej kompozytowego elektrolitu 3-YSZ-Al2O3 w stosunku do materiałów elektrodowych do zastosowania w średniotemperaturowych ogniwach paliwowych
PublicationJednym z podstawowych wymogów stawianych mate- riałom na elektrolity do średniotemperaturowych ogniw paliwowych IT-SOFC (ang. intermediate-temperature solid oxide fuel cells) jest ich kompatybilność chemiczna z elektrodami w temperaturach zarówno eksploatacji, jak i wytwarzania ogniw. W celu sprawdzenia, czy badany w pracy kompozytowy elektrolit o osnowie z częściowo stabilizowanego ditlenku cyrkonu i z wtrąceniami tlenku glinu...
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Characteristic of Morpholinium Ionic Liquids as Gas Chromatography Stationary Phases with McReynolds Constants and Activity Coefficients at Infinite Dilution
PublicationIn this work, four ionic liquids based on N-alkyl-N-methylmorpholinium cation ([Mor1,R] where R= 2, 4, 8, 10) and bis(trifluoromethanesulfonyl)imide anion [TFSI] were synthesized. Using gas-liquid chromatography a number of parameters describing the sorption properties of the investigated ionic liquids were determined. The values of Kovats indices, McReynolds constants, and activity coefficients at infinite dilution were the basis...
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Influence of the position of the swash plate rotation axis on the volumetric efficiency of the axial pistons pumps
PublicationThe article describes the influence of the position of the swash plate axis of rotation on the size of the dead space and the volumetric efficiency of the axial pistons pump. Superposition of the two motions have been proposed - the rotation of the swash plate with respect to axis intersecting the axis of rotation of the pump shaft and the shifts of swash plate yielding a result of the rotation axis offset effect. In the article...
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On dynamics of origami-inspired rod
PublicationWe discuss the dynamics of a relatively simple origami-inspired structure considering discrete and continuum models. The latter was derived as a certain limit of the discrete model. Here we analyze small in-plane deformations and related equations of infinitesimal motions. For both models, dispersion relations were derived and compared. The comparison of the dispersion relations showed that the continuum model can capture the behavior...
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Motyw autonomii a oczekiwany i faktyczny poziom satysfakcji z prowadzenia działalności gospodarczej
PublicationMotyw autonomii jest niejednokrotnie wskazywany jako jeden z istotniejszych czynników skłaniających ludzi do założenia własnej działalności gospodarczej, choć nie dla każdego przedsiębiorcy jest równie ważny. W opracowaniu zaprezentowano wyniki badań przeprowadzonych w grupie początkujących przedsiębiorców. Osoby deklarujące kierowanie się motywem autonomii oczekiwały, że uzyskają wyższy poziom satysfakcji po roku prowadzenia działalności...
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Cyfrowy akcelerator wybranych modułów standardu kompresji wideo H.264
PublicationW artykule przedstawiono konfigurowalny cyfrowy akcelerator estymacji ruchu przeznaczony dla enkodera wideo standardu H.264. Akcelerator został zaimplementowany w technologii FPGA oraz w układzie ASIC w technologii UMC 90 nm. Obie implementacje zostały zweryfikowane, a szczegółowe wyniki pomiarów akceleratora ASIC zostały porównane z innymi dostępnymi w literaturze propozycjami. System został zoptymalizowany do współpracy z oprogramowaniem...
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Analysis of the Heating Process of Hydraulic Motors during Start-Up in Thermal Shock Conditions
PublicationConditions that prevail during harsh winters and hot summers pose a serious challenge for machine designers building devices suitable for operation in extreme weather. It is essential for the designers and the users to define the principles and conditions for the safe operation of machines and devices with hydraulic drive in low ambient temperatures. Bearing in mind the above, the author tested the hydraulic motors in thermal shock...
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Asymmetrical Modes in Polyphase Motors and Drives
PublicationThe effect of power supply and/or motor asymmetry on the phase-load distribution and the ripple of electromagnetic torque in a polyphase drive is studied by the method of symmetrical components. It is shown that the presence of asymmetry causes the mapping of all harmonics in the supply voltage into all planes of symmetrical components and eliminates the possibility of independent control of harmonics. The dynamic model of a five-phase...
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Aleksandra Parteka dr hab. inż.
PeopleAbout me: I am an associate professor and head of doctoral studies at the Faculty of Management and Economics, Gdansk University of Technology (GdanskTech, Poland). I got my MSc degree in Economics from Gdansk University of Technology (2003) and Universita’ Politecnica delle Marche (2005), as well as MA degree in Contemporary European Studies from Sussex University (2006, with distinction). I received my PhD in Economics...
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Ionization and ionic fragmentation of tetrahydrofuran molecules by electron collisions
PublicationElectron impact ionization and ionic fragmentation of tetrahydrofuran molecules in the gas phase were studied in the energy range from ionization threshold up to 150 eV using the technique of mass spectrometry. The cation mass spectra, ionization and ionic fragmentation efficiencies were measured over this energy range. Well-resolved mass peaks were detected in the mass range 10-72 amu and assigned to corresponding ionic molecular...
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Ionization and fragmentation of furan molecules by electron collisions
PublicationCation mass spectra obtained by electron impact were measured to investigate the ionization and ionic fragmentation of furan, C4H4O, molecules in the gas phase. The most abundant cations, with comparable intensities in the mass spectra, were the parent, C4H4O+, cation (68 amu) and the C3H3+ fragment (39 amu). The appearance energies of most of the observed ionic fragments were determined and the possible fragmentation processes...
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Marcinkiewicz Averages of Smooth Orthogonal Projections on Sphere
PublicationWe construct a single smooth orthogonal projection with desired localization whose average under a group action yields the decomposition of the identity operator. For any full rank lattice \Gamma ⊂ R^d , a smooth projection is localized in a neighborhood of an arbitrary precompact fundamental domain R^d / \Gamma. We also show the existence of a highly localized smooth orthogonal projection, whose Marcinkiewicz average under the...
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Broadcast copies reveal the quantumness of correlations
PublicationWe study the quantumness of bipartite correlations by proposing a quantity that combines a measure of total correlations-mutual information-with the notion of broadcast copies-i.e., generally nonfactorized copies-of bipartite states. By analyzing how our quantity increases with the number of broadcast copies, we are able to classify classical, separable, and entangled states. This motivates the definition of the broadcast regularization...
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Contextualizing a Knowledge Base by Approximation – A Case Study
PublicationModular knowledge bases give their users opportunity to store and access knowledge at different levels of generality. In this paper we present how to organize a modular knowledge bases organized into contexts in which a user can express their knowledge in much simplified way, yet without losing its precision. The work is centered around the notion of approximation - i.e. reducing the arity of predicates used. The presentation is...
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A study on signal processing methods applied to hearing aids
PublicationThis paper presents a short survey on current technology available in hearing aids with a focus on digital signal processing techniques used. First, factors influencing the hearing aid effectiveness are introduced. Then, examples of the present DSP methods and strategies are provided. Also, a description of current limitations of hearing aids and future trends of development are shown. Finally, the notion of computational auditory...
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Effect of Aromatic System Expansion on Crystal Structures of 1,2,5-Thia- and 1,2,5-Selenadiazoles and Their Quaternary Salts: Synthesis, Structure, and Spectroscopic Properties
PublicationRational manipulation of secondary bonding interactions is a crucial factor in the construction of new chalcogenadiazole-based materials. This article reports detailed experimental studies on phenanthro[9,10-c][1,2,5]chalcogenadiazolium and 2,1,3-benzochalcogenadiazolium salts and their precursors. The compounds were synthesized, characterized employing NMR and UV-Vis spectroscopy. TD-DFT calculations were also performed. The influence...