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Gdańsk University of Technology

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Publications from the year 2013

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  • Hybrid electrode materials for fast performance devices
    • Anna Lisowska-Oleksiak
    • Konrad Trzciński
    2013 Biuletyn Polskiego Stowarzyszenia Wodoru i Ogniw Paliwowych

    Energy storage devices such as Electrochemical Double Layer Capacitors and other types of the electrochemical capacitors require chemically stable, non-soluble, electrochemically active electrode materials compatible with appropriate electrolytes. Factors which determine their applicability are derived from so called electrochemical window of electroltes, nature of charge accumulation and their kinetics. On the other hand technological aspects related to the electrode film formation or importance considering transference of experimental laboratory data into manufacture of the device scale. Therefore many attemps have been made towards formation of the hybrid systems comprising different type of compounds in systems formed to act as the electrodes in fast charging-discharging devieces. There are two main ways to combine in one electrode materials different counterparts: 1) the first conceps is aimed towards harvesting of electroactivity from components active at the same potential range, 2) in the second approach used components are electroactive at the different potential range (expanding E function) also synergy between their activity is expected. Both cases should bring about increase in electric energy storage, however in different way. In the first group of hybrid materials the example is organic/inorganic composite systems made of polymer and metal hexacyan0oferrates. The example of second type of hybrids is composite made on non metal doped titania combined with organic conducting film. Here a pseudofaradaic reaction at the TiO2 surface, active at hig anodic polarization is overlapping with pseudofaraic current of positively charged polymer. This composite works both in contact with aqueous and non-aqueous electrolytes. In non-aqueous electrolytes the benefit of the combined material is reached as the activity is observed from 3.8 V up to 0.7 V vs Li/Li+. Moreover titania is undergoing slower intercalation reaction. The usage of graphene in a composite should bring about improvement of electrode performance. However it is not the straightforward case for graphene implementation when ion-to-electron transducer is required for good electric connection between counterparts (PEDOT + TiO2)

  • Hybrid model of geared rotor system
    • Rafał Hein
    • Cezary Orlikowski
    2013 Full text Diagnostyka

    In the paper a hybrid model of a geared multirotor system has been developed. The model is obtained by application of both the modal decomposition methodology and the spatial discretization method. Reduced modal model was constructed for the system without gyroscopic and damping effects. The gyroscopic interaction, damping and other phenomena which are difficult to include in the modal approach were modeled by application of simply lumping technique. Such approach enables to obtain accurate, low order model of geared rotor system with coupled bending and torsional vibrations. In the model it is possible to include nonproportional or nonlinear damping. Obtained hybrid model has been compared with high order FEM model. Simulation results prove that proposed method of modeling is efficient and relatively easy to use.

  • Hybrid of Neural Networks and Hidden Markov Models as a modern approach to speech recognition systems
    • Paweł Sokólski
    • Tomasz Adam Rutkowski
    2013 Full text Pomiary Automatyka Robotyka

    The aim of this paper is to present a hybrid algorithm that combines the advantages ofartificial neural networks and hidden Markov models in speech recognition for control purpos-es. The scope of the paper includes review of currently used solutions, description and analysis of implementation of selected artificial neural network (NN) structures and hidden Markov mod-els (HMM). The main part of the paper consists of a description of development and implementation of a hybrid algorithm of speech recognition using NN and HMM and presentation of verification of correctness results.

  • HYBRID REDUCED MODEL OF ROTOR
    • Rafał Hein
    • Cezary Orlikowski
    2013 Full text Archive of Mechanical Engineering

    In the paper, the authors describe the method of model reduction of a rotor system. The proposed approach enables to obtain a low order model including e.g. nonproportional damping or the gyroscopic effect. This method is illustrated using the example of a rotor system. First, a model of the system was built without gyroscopic and damping effects by using the rigid finite element method. Next, this model was reduced. Finally, two identical, low order, reduced models in two perpendicular planes were coupled together by means of gyroscopic and damping interaction to form one model of the system. Thus a hybrid model is obtained. The advantage of the presented method is that the number of gyroscopic and damping interactions does not affect the model range.

  • Hybrid SONIC: joint feedforward–feedback narrowband interference canceler
    • Maciej Niedźwiecki
    • Michał Meller
    2013 Full text INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING

    SONIC (self-optimizing narrowband interference canceler) is an acronym of a recently proposed active noise control algorithm with interesting adaptivity and robustness properties. SONIC is a purely feedback controller, capable of rejecting nonstationary sinusoidal disturbances (with time-varying amplitude and/or frequency) in the presence of plant (secondary path) uncertainty. We show that although SONIC can work reliably without access to a reference signal, even when the frequency of the disturbance is unknown and possibly time varying, the algorithm can take advantage of such additional source information. Unlike classical hybrid solutions, the reference signal is used only to extract information about the instantaneous frequency of the disturbance. The advance-time advantage, available because the acoustic delay in the system is larger than the electrical delay, allows one to incorporate in the control loop a smoothed, and hence more accurate, frequency estimate. This increases the attenuation efficiency of SONIC and widens its operating range—the modified algorithm can be safely used in the presence of rapid frequency changes. Copyright © 2013 John Wiley & Sons, Ltd

  • Hybrid Technique Combining the FDTD Method and Its Convolution Formulation Based on the Discrete Green's Function
    • Tomasz Stefański
    2013 IEEE Antennas and Wireless Propagation Letters

    In this letter, a technique combining the finite-difference time-domain (FDTD) method and its formulation based on the discrete Green's function (DGF) is presented. The hybrid method is applicable to inhomogeneous dielectric structures that are mutually coupled with wire antennas. The method employs the surface equivalence theorem in the discrete domain to separate the problem into a dielectric domain simulated using the FDTD method and a wire antenna simulated using the DGF formulation of the FDTD method. Therefore, both methods can be perfectly coupled without introducing any additional errors to the FDTD solution. Applications of the hybrid FDTD method are illustrated by two canonical problems involving half-wavelength dipole antennas and a dielectric object. If the DGF length is equal to the number of iterations in a simulation, the presented hybrid technique returns the same results as the direct FDTD method (assuming infinite numerical precision of computations).

  • Hybrid technique for the analysis of scattering from periodic structures composed of irregular objects
    • Adam Kusiek
    • Rafał Lech
    • Jerzy Mazur
    2013 Progress in Electromagnetics Research-PIER

    W pracy zaproponowano nową metodę hybrydową do badania zjawiska rozpraszania fali elektromagnetycznej na strukturach periodycznych złożonych z obiektów rozpraszających o nieregularnym kształcie. Zaprezentowana metoda została wykorzystana do badania własności nowych struktur falowych. Uzyskane wyniki numeryczne zostały zweryfikowane eksperymentalnie.

  • Hydrauliczna wiarygodność wyników pomiarów terenowych stosowanych do identyfikacji oporności hydraulicznej przewymiarowanych sieci wodociągowych
    • Marian Kulbik
    2013 Instal

    Publikacja zawiera zalecenia metodyczne dotyczące identyfikacji oporności hydraulicznej w przewymiarowanych sieciach wodociągowych na tle spotykanych nieprawidłowości. Krytycznie oceniono wyniki pomiarów terenowych, które zastosowano do tarowania komputerowych modeli przepływów (KMP) pomimo, że nie spełniały kryterium hydraulicznej wiarygodności. Ponadto zaproponowano spadek hydrauliczny jako obiektywny wskaźnik wiarygodności pomiarów, aby ograniczyć spotykaną dowolność w ocenie danych, ze względu na brak standaryzacji w Polsce. Podstawą wyboru wskaźnika były wyniki analizy kształtowania się spadku hydraulicznego w funkcji prędkości i współczynnika chropowatości ścian rurociągów. Na tej podstawie uznano za konieczne zapewnienie spadku hydraulicznego na poziomie co najmniej 10 ‰ podczas pomiarów w przewymiarowanych sieciach wodociągowych. W tych warunkach hydraulicznych uzyskanie wiarygodnych danych pomiarowych wymaga dodatkowego obciążenia sieci wodociągowej przez zastosowanie tzw. metody przepływu pożarowego. Skuteczność metody potwierdzono wynikami własnych badań terenowych, które wykorzystano do kalibracji parametrów ośmiu komputerowych modeli przepływów utworzonych przez autora.

  • HYDROACOUSTIC NOISE MEASUREMENTS
    • Eugeniusz Kozaczka
    2013

    The paper deals mainly with investigation of underwater noise that propagation is in shallow water. In this paper has been presented the experimental investigation results concerning the distribution of the sound field pressure generated by moving ships in the shallow water at the small distance from the ship. The main acoustical characteristics describing features of the field are spectrograms in pseudo 3D system – distance and frequency and sound intensity. Results pointed individual features of ship are known often as an acoustical signature of the ship. The two main sources of the ship will be taken into account. Vibration energy generated by the mechanisms is transferred through structural elements to surrounding water where it propagates in the form of acoustic waves of broadband frequencies. Also the noise generated by the ship propeller will be matter of interest.

  • Hydrodynamic Pressure Field of a Ship on Shallow Water
    • Jan Bielański
    2013

    Results of calculations of the hydrodynamic pressure field around the ship were obtained by application of the boundary element method. Hydrodynamic field was calculated for a Polish Navy’s tugboat and transport ship using a program called SHiPP and compared with measurements of the field taken on river near Swinoujscie for two identical tugs H-4 and H-10. Next, a series of HPF calculations was carried out on planes situated at various depths for constant bottom depth as well as for various bottom depths. Relationships between HPF at various depths were found and illustrated with examples.

  • Hydrothermal reactions: From the synthesis of ligand to new lanthanide 3D-coordination polymers
    • Fausthon Fred da Silva
    • Carlos Alberto Fernandes de Oliveira
    • Eduardo Henrique Lago Falcao
    • Claudia Cristina Gatto
    • Nivan Bezerra da Costa Jr
    • Ricardo Oliveira Freire
    • Jarosław Chojnacki
    • Severino Alves Junior
    2013 JOURNAL OF SOLID STATE CHEMISTRY

    The organic ligand 2,5-piperazinedione-1,4-diaceticacid (H2PDA) was synthesized under hydrothermal conditions starting from the iminodiacetic acid and catalyzed by oxalic acid. The X-ray powder diffraction data indicates that the compound crystallizes in the P21/c space group as reported in the literature. The ligand was also characterized by elemental analysis, magnetic nuclear resonance, infrared spectroscopy and thermogravimetric analysis. Two new coordination networks based on lanthanide ions were obtained with this ligand using hydrothermal reaction. In addition to single-crystal X-ray diffraction, the compounds were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis. Single-crystal XRD showed that the compounds are isostructural, crystallizing in P21/n space group with chemical formula [Ln(PDA)1.5(H2O)](H2O)3 (Ln¼Gd3þ (1) and Eu3þ (2)). The luminescence properties of both compounds were studied. In the compound (1), a broad emission band was observed at 479nm, red shifted by 70nm in comparison of the free ligand.In (2), the typical f–f transition was observed with amaximum peak at 618 nm, related with the redemissionoftheeuropiumions.Computationalmethodswereperformedtosimulatethe crystal structureof (2). The theoretical calculationsoftheintensityparametersareingoodagreement with theexperimentalvalues.

  • Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
    • Anna Perelomova
    2013 Full text CENTRAL EUROPEAN JOURNAL OF PHYSICS

    Evolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy of a medium decreases. Variations in the internal energy of a gas are proportional to some generic parameter, the sign of which is responsible for acoustical activity, and depends on intensity and shape of the sound waveform. Hysteresis curves in the plane of thermodynamic states are plotted. Curves for harmonic and several aperiodic sound impulses are plotted, discussed and compared.

  • I Triennale Sztuki Pomorskiej, Sopot 2013
    • Ryszard Grodnicki
    2013

    Katalog towarzyszący wystawie, która odbyła się w Państwowej Galerii Sztuki w Sopocie w terminie 26.01 – 3.03. 2013 roku. Publikacja liczy 92 strony i zawiera 68 reprodukcje prac i noty biograficzne i teksty krytyczne w języku polskim i angielskim. ISBN 978-83-61270-55-3.

  • IDENTIFICATION AND COMPARATIVE ANALYSIS OF FACTORS INFLUENCING ROAD SAFETY IN US REGIONS AND IN POLISH VOIVODESHIPS
    • Joanna Wachnicka
    2013 Full text Transport Problems

    Analyses of road safety at national level have been run for many years and large number of publications concerning them appeared so far. How interdisciplinary the issue is, has been shown by literature studies done by the author of the paper. It appears that economists, mathematicians, doctors as well as engineers have studied the issue. It is not an easy one, as results of many analyses lead to conflicting conclusions and often fail to provide straightforward answers to questions asked. The administrative actions taken to improve road safety, uniform for the whole country, frequently fail to give expected results, including Poland’s case. Therefore there is a need to analyse what makes some provinces, and not the others, report improvement in road safety. This paper presents part of the work on author’s doctoral thesis, which analyses how regional characteristics may impact road safety in respective regions. However, during collection of data for the purpose of the doctoral thesis it turned out that many variables mentioned in literature as significant had not been collected on regional level in Europe, including Poland. There are, though, available data on respective American states, so the search for the best describing independent variables started from the analyses of US data. The analyses showed the impact of factors such as annual income per capita, transport activity, density of population, seatbelt rates, road and vehicle density, rate of doctors.

  • Identification of Emotional States Using Phantom Miro M310 Camera
    • Marek Przyborski
    2013 Internal Security

    The purpose of this paper is to present the possibilities associated with the use of remote sensing methods in identifying human emotional states, and to present the results of the research conducted by the authors in this field. The studies presented involved the use of advanced image analysis to identify areas on the human face that change their activity along with emotional expression. Most of the research carried out in laboratories is limited to the segmentation of the analyzed image, and then studying the changes in specific segments, so we have to deal with averaging information which is contained in the processed image. In the following sections we have described a method of acquiring and processing images of the human face, recorded by the Phantom MIRO 310 camera, for presenting specific states of the human brain while the emotional state is changing. Each emotion was expressed for 2 seconds. The resulting images are of a high technical quality and represent a series of frames recorded at the speed of 1000 frames per second. The method presented is based on assumptions drawn from Particle Image Velocimetry (PIV) which is well known in the field of fluid dynamics. The tracking algorithm lets us trace all identified objects on the human face and calculate different statistics. Thus we may identify some patterns created by moving objects on the face, which might be useful in the process of recognition of different emotional states.

  • Identification of the mechanical properties of the skin by electromechanical impedance analysis of resonant piezoelectric actuator
    • Łukasz Sienkiewicz
    • Jean-Francois Rouchon
    • Mieczysław Ronkowski
    • Grzegorz Andrzej Kostro
    • Roland Ryndzionek
    2013

    This paper is devoted to the analysis and verification of developed piezoelectric sensor/actuator for measuring the mechanical properties of soft tissues, especially human skin. The key element of the measurement structure is an electromechanical system that uses both the reverse piezoelectric effect (vibration generation – stimulation of the tissues in the appropriate frequency range) and direct piezoelectric effect (system response registration). By analyzing the response of the piezoelectric sensor/actuator - an electromechanical signature of the tested tissue, it is possible to identify a series of mechanical quantities describing the tested object, such as stiffness, viscosity, Young's modulus. An analytical approach is shown in order to establish a link between the electromechanical equivalent circuit obtained for a resonance frequency of the actuator and the calculations based on the Hertz’s contact mechanics theory. A finite element method analysis is then presented in order to assess the performance of the chosen topology of piezoelectric sensor/actuator. Finally, the proposed method of impedance characterization is verified experimentally by a prototype of piezoelectric bimorph sensor/actuator.

  • Identyfikacja dynamiczna i ocena odporności sejsmicznej konstrukcji dwukolumnowego odłącznika wysokiego napięcia
    • Paweł Dembowski
    2013

    Sprawność elementów sieci energetycznej po trzęsieniu ziemi jest bardzo ważnym elementem bezpieczeństwa na obszarze objętym kataklizmem. Brak elektryczności poważnie utrudnia prowadzenie akcji ratunkowej, potęguje chaos, wzmaga panikę wśród mieszkańców. Tymczasem w przeszłości wielokrotnie obserwowano uszkodzenia elementów infrastruktury energetycznej na skutek wstrząsów sejsmicznych. Istotnym elementem systemu energetycznego są tzw. odłączniki wysokiego napięcia, które służą do galwanicznego oddzielania obwodów w stanie otwartym (np. podczas remontów) i tworzą bezpieczną i widoczną przerwę izolacyjną. Celem niniejszej dysertacji jest przeprowadzenie kompleksowych badań dotyczących identyfikacji dynamicznej i oceny odporności sejsmicznej dwukolumnowego odłącznika wysokiego napięcia z uwzględnieniem zniszczeniowych testów eksperymentalnych oraz nieliniowych analiz numerycznych. W pierwszej części pracy szczegółowo opisano badania eksperymentalne analizowanej konstrukcji odłącznika. Najpierw przeprowadzono szereg badań impulsowych po zamocowaniu urządzenia na sztywnym fundamencie, w celu wyznaczenia dominujących częstotliwości oraz form drgań własnych konstrukcji dla konfiguracji zamkniętej oraz otwartej. Dalsze badania przeprowadzano na stole wstrząsowym, na którym powtórzono testy impulsowe oraz wykonano testy sweep-sine. W ostatnim etapie badań eksperymentalnych wykonano testy zniszczeniowe mające na celu określenie odporności sejsmicznej analizowanego odłącznika. W drugiej części dysertacji przedstawiono wyniki dokładnych analiz numerycznych z zastosowaniem metody elementów skończonych. Najpierw wykonano analizę modalną w celu weryfikacji dokładności stworzonego modelu numerycznego. Następnie przeprowadzono trójwymiarową nieliniową analizę dynamiczną przy wymuszeniu zapisami różnych trzęsień ziemi (El Centro 1940, Kobe 1995, Kushiro 1993 oraz San Fernando 1971) obejmującą nieliniowość materiałową oraz geometryczną. W ostatnim etapie badań przeprowadzono analizę parametryczną dla różnych wartości siły ściskającej ramiona toru prądowego dla konfiguracji zamkniętej odłącznika.

  • Identyfikacja gatunku stali w elementach stalowych poddanych działaniu wysokiej temperatury
    • Dariusz Kowalski
    • Elżbieta Urbańska-Galewska
    2013

    Dokonano identyfikacji gatunku stali konstrukcyjnej budowlanej w dostarczonych próbkach materiałowych pobranych z konstrukcji poddanej obciążeniu temperaturowemu w sytuacji pożarowej. Wykonano badania spektrometryczne i twardości dostarczonego materiału w celu dokonaniu identyfikacji cech i określenia rodzaju materiału stalowego. Przeprowadzono analizę porównawczą przeprowadzonych badań w porównaniu z badaniami wytrzymałościowymi.

  • Identyfikacja parametrów modalnych kładki dla pieszych przy użyciu wzbudzenia impulsowego
    • Magdalena Rucka
    • Łukasz Żmuda-Trzebiatowski
    2013 Inżynieria i Budownictwo

    Celem niniejszej pracy jest analiza możliwości wzbudzania kładek dla pieszych przy użyciu młotka modalnego. W artykule przedstawiono identyfikację częstotliwości i postaci drgań własnych oraz współczynników tłumienia kładki dla pieszych za pomocą eksperymentalnej analizy modalnej a także porównanie wyników otrzymanych z badań eksperymentalnych z wynikami modelu numerycznego.

  • IDENTYFIKACJA POWIĄZAŃ POMIĘDZY KATEGORIAMI WIKIPEDII Z UŻYCIEM MIAR PODOBIEŃSTWA ARTYKUŁÓW
    • Julian Szymański
    • Marcin Deptuła
    • Henryk Krawczyk
    2013 Studia Informatica Pomerania

    W artykule opisano podejście do identyfikacji powiązań między kategoriami w repozytorium danych tekstowych, bazując na Wikipedii. Przeprowadzając analizę podobieństwa między artykułami określono miary pozwalające zidentyfikować powiązania między kategoriami, które nie były wcześniej uwzględnione i nadawać im wagi określające stopień istotności. Przeprowadzono automatyczną ocenę uzyskanych rezultatów w odniesieniu do już istniejącej struktury kategorii.