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Gdańsk University of Technology

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Publications from the year 2015

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  • Performance evaluation of parallel background subtraction on GPU platforms
    • Grzegorz Szwoch
    2015 Elektronika : konstrukcje, technologie, zastosowania

    Implementation of the background subtraction algorithm on parallel GPUs is presented. The algorithm processes video streams and extracts foreground pixels. The work focuses on optimizing parallel algorithm implementation by taking into account specific features of the GPU architecture, such as memory access, data transfers and work group organization. The algorithm is implemented in both OpenCL and CUDA. Various optimizations of the algorithm are presented and tested using devices with varying processing power, including desktop PC graphic cards, ultrabooks and Tegra mobile processor. The main aim of the work is to determine if the optimized algorithm run on currently available GPUs is able to perform on-line processing of high resolution video streams.

  • Performance improvement of NN based RTLS by customization of NN structure - heuristic approach
    • Bartosz Jachimczyk
    • Damian Dziak
    • Wlodek Kulesza
    2015

    The purpose of this research is to improve performance of the Hybrid Scene Analysis – Neural Network indoor localization algorithm applied in Real-time Locating System, RTLS. A properly customized structure of Neural Network and training algorithms for specific operating environment will enhance the system’s performance in terms of localization accuracy and precision. Due to nonlinearity and model complexity, a heuristic analysis is suitable to evaluate NN performance for different environmental conditions. Efficiency of the proposed customization of a Neural Network is verified by simulations and validated by physical experiments. This research also concerns the influence of size of Neural Network training set. The results prove that, better localization accuracy is with a NN system which is properly customized with respect to a training method, number of neurons and type of transfer function in the hidden layer and also type of transfer function in the output layer.

  • Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
    • Janusz Cieśliński
    • Wojciech Miciak
    • Artur Fiuk
    • Bartłomiej Siemieńczuk
    2015

    This study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break of operation of the tested PHEx on its performance was of particular interest. Pressure drop in all runs was measured as well. The Wilson approach was applied in order to estimate heat transfer coefficients for the PHEx passages. It was observed, that addition of nanoparticles resulted in deterioration of an overall heat transfer coefficient for the selected PHEx and tested conditions, i.e. temperature range and Reynolds number. Moreover, substantial increase of pressure drop was recorded after each break of operation of the tested PHEx

  • Performance of a plate heat exchanger operated with water-Al2O3 nanofluid
    • Janusz Cieśliński
    • Artur Fiuk
    • Wojciech Miciak
    • Bartłomiej Siemieńczuk
    2015

    This study is focused on experimental investigation of a selected type of brazed plate heat exchanger (PHEx). The main aim of the paper was to experimentally check the ability of nanofluids to enhance the performance of PHEx. A typical water-Al2O3 nanofluid was tested and compared to that of the base fluid, i.e. water. Nanoparticles were tested at the concentration of 0.1% and 1% by weight. Impact of the 1 day and 3 days break of operation of the tested PHEx on its performance was of particular interest. Pressure drop in all runs was measured as well. The Wilson approach was applied in order to estimate heat transfer coefficients for the PHEx passages. It was observed, that addition of nanoparticles resulted in deterioration of an overall heat transfer coefficient for the selected PHEx and tested conditions, i.e. temperature range and Reynolds number. Moreover, substantial increase of pressure drop was recorded after each break of operation of the tested PHEx.

  • Performance of DS-CDMA Radionavigation Receiver with Subsample Time Measurement Resolution in Various Environments
    • Jarosław Sadowski
    2015

    This paper presents results of investigation of position estimation performance in TDOA radionavigation system with receiver containing code tracking loop with subsample time measurement resolution. Position estimation accuracy was evaluated using real signals from CDMA base stations, recorded during measurement campaigns in various environments: on sea, flat terrain and hilly terrain.

  • Performance of the flat plate solar collector operated with water-Al2O3 nanofluid
    • Janusz Cieśliński
    • Bartosz Dawidowicz
    • Aleksandra Popakul
    2015

    This paper shows the experimental results of the performance a flat plate solar collector with water-Al2O3 nanofluid as a working fluid. The weight fractions of nanoparticles were 0.1%, 0.2% and 0.4%. The volume flow rate of nanofluid varied from 60 l/h to 170 l/h. The results show that application of nanofluids instead of pure water resulted in higher efficiency of the tested flat plate solar collector for given range of thermal radiation.

  • Perovskite-type KTaO3–reduced graphene oxide hybrid with improved visible light photocatalytic activity
    • Beata Bajorowicz
    • J. Reszczyńska
    • W. Lisowski
    • Tomasz Klimczuk
    • Michał Jerzy Winiarski
    • M. Słoma
    • Adriana Zaleska-Medynska
    2015 RSC Advances

    Novel rGO–KTaO3 composites with various graphene content were successfully synthesized using a facile solvothermal method which allowed both the reduction of graphene oxide and loading of KTaO3 nanocubes on the graphene sheets. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) specific surface area, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), UV-Vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) emission spectroscopy. The obtained rGO–KTaO3 composites showed greatly improved photocatalytic performance for degradation of phenol under visible light irradiation (λ > 420 nm) over pristine KTaO3 which could be related to the photosensitizer role of graphene in the rGO–KTaO3 composites as well as the formation of p–n heterojunctions between KTaO3 nanocubes and rGO sheets. The highest photocatalytic activity in phenol degradation reaction was observed for rGO–KTaO3 hybrid with 30 wt% graphene. The enhanced photoactivity of this composite could be attributed to the synergistic effect of several factors such as: small crystallite size, extended absorption range in the visible spectrum and intimate contact between graphene and KTaO3 cubes.

  • Personal adaptive tuning of mobile computer audio
    • Kuba Łopatka
    • Józef Kotus
    • Piotr Suchomski
    • Andrzej Czyżewski
    • Bożena Kostek
    2015

    An integrated methodology for enhancing audio quality in mobile computers is presented. The key features are adaptation of the characteristics of the acoustic track to the changing conditions and to the user's individual preferences. Original signal processing algorithms are introduced, which concern: linearization of frequency response, dialogue intelligibility enhancement and dynamics processing tuned up to the user's preferences. The details of the algorithm implemented in the C++ programming language are provided. The processing is performed utilizing custom Audio Processing Objects (APO) installed in Windows sound system. The sound enhancement bundle is managed with a User Interface enabling control over the sound system. The results of subjective evaluation of the introduced methods devices are discussed.

  • Perspectives on the replacement of harmful organic solvents in analytical methodologies: a framework toward the implementation of a generation of eco-friendly alternatives
    • Pena-pereira Francisco
    • Adam Kloskowski
    • Jacek Namieśnik
    2015 GREEN CHEMISTRY

    Volatile organic solvents derived from non-renewable fossil feedstocks are commonplace in analytical laboratories. In spite of their convenient performance in countless unit operations, their environmental, health and safety issues represent a major area of concern. The progressive replacement of organic solvents obtained from fossil resources by eco-friendly alternatives would involve remarkable advances within the framework of green analytical chemistry, while avoiding future uncertainties regarding forthcoming regulations. This perspective tackles the problem of organic solvent use in analytical methodologies, providing relevant information for solvent selection and identifying a range of solvents derived from natural and/or renewable resources, namely bio-based molecular solvents, ionic liquids composed wholly of biomaterials and natural deep eutectic mixtures that could potentially be exploited toward advanced, more benign, analytical methodologies. In addition, physicochemical properties are provided, and a number of challenging aspects to be considered in the implementation of eco-friendly alternatives are evaluated.

  • Perspektywy wykorzystania architektury korporacyjnej w tworzeniu rozwiązań smart city
    • Jerzy Gołuchowski
    • Marcin Korzeb
    • Paweł Weichbroth
    2015 Full text Roczniki Kolegium Analiz Ekonomicznych

    Idea jaką jest SmartCity jest na tyle nowa, iż trudno znaleźć kompleksowy i w pełni działający system obejmujący wszystkich jego interesariuszy oraz ich wymagania względem niego – rozumianego jako przedsięwzięcie, a nie system informatyczny. Obecnie prowadzonych jest wiele projektów o których można powiedzieć, iż są to projekty „wyspowe” - obejmują tylko jedno, lub kilka zagadnień (domen, aspektów), związanych z zarządzaniem przestrzenią miejską w kontekście inteligentnych miast. Z założenia kompleksowe podejście do wdrożenia idei SmartCity powinno natomiast obejmować wszystkie aspekty zarządzania miastem i przepływem informacji, pomiędzy wszystkimi interesariuszami istniejącymi w danej przestrzeni publicznej. Zatem projektowany system powinien obejmować przepływy i interakcje w każdym obszarze życia i przestrzeni publicznej, co oznacza iż jest to wielopoziomowe i złożone zadanie. W przestrzeni miejskiej można wyróżnić kilka grup interesariuszy, począwszy od władz szczebla samorządowego, jednostki oświatowe i działające w obszarze ochrony zdrowia, stowarzyszenia, uczelnie wyższe i ośrodki naukowo badawcze, instytuty czy też podmioty gospodarcze, ostatecznie są mieszkańcy regionu oraz inni aktorzy pośrednio związani z projektowanym systemem. Zarówno na świeci, tak i w Polsce, koncepcja architektury korporacyjnej zaczyna być stosowana na szeroką skalę. Zastosowania dotyczą takich obszarów jak: zbiór właściwości danej organizacji lub całego systemu, formalny opis struktury i funkcji poszczególnych komponentów, czy też wzajemnych powiązań między tymi komponentami. Ponadto, pojęcie architektury korporacyjnej może stanowić o działalności w zakresie definiowania, reprezentacji i zarządzania kluczowymi elementami systemu. Należy stwierdzić, iż w chwili obecnej brak jest usystematyzowanego podejścia do kompleksowych wdrożeń idei Smart City, a tym samym do transformacji przestrzeni publicznej z przestrzeni reagującej post-factum na przestrzeń reagującą ex-ante. Czy można zidentyfikować przesłanki opracowania referencyjnego modelu dla powyższego zagadnienia i czy w tym celu można wykorzystać architekturę korporacyjną jako skuteczne narzędzie? Czym różni się korporacja od systemu, a właściwie od ekosystemu, jakim jest inteligentne miasto i czy może mieć tutaj zastosowanie architektura korporacyjna? Na te pytania autorzy niniejszego artykułu postarali się odpowiedzieć w przedmiotowej publikacji.

  • Perspektywy wykorzystania gazu ziemnego do produkcji energii elektrycznej w Polsce
    • Paweł Bućko
    2015 Rynek Energii

    W artykule omówiono podstawowe przesłanki, które mogą decydować o wykorzystaniu technologii gazowych do produkcji energii elektrycznej w Polsce. Przedstawiono aktualną strukturę wytwarzania energii elektrycznej w krajowym systemie elektroenergetycznym. Zostały przedstawione prognozy wzrostu zapotrzebowania na energię elektryczną w perspektywie 2030 r. Wskazano na konieczność zmiany bazy paliw dla systemu elektroenergetycznego. Zwrócono uwagę na ograniczenia wynikające z emisji CO2. Dokonano analizy konkurencyjności technologii gazowych w stosunku do innych perspektywicznych technologii produkcji energii elektrycznej. Omówiono miejsce gazu w bilansie paliw dla energetyki w średnioterminowych prognozach rozwoju polskiego systemu elektroenergetycznego.

  • Phase Transition in a Sequence-Structure Channel
    • Abram Magner
    • Daisuke Kihara
    • Wojciech Szpankowski
    2015

    We study an interesting channel which maps binary sequences to self-avoiding walks in the two-dimensional grid, inspired by a model of protein folding from statistical physics. The channel is characterized by a Boltzmann/Gibbs distribution with a free parameter corresponding to temperature. We estimate the conditional entropy between the input sequence and the output fold, giving an upper bound which exhibits an unusual phase transition with respect to temperaturę

  • PHONEME DISTORTION IN PUBLIC ADDRESS SYSTEMS
    • Iwona Kochańska
    • Henryk Lasota
    2015

    The quality of voice messages in speech reinforcement and public address systems is often poor. The sound engineering projects of such systems take care of sound intensity and possible reverberation phenomena in public space without, however, considering the influence of acoustic interference related to the number and distribution of loudspeakers. This paper presents the results of measurements and numerical simulations of the impact of the multiplication of sound sources in a room on phoneme formants distribution playing a crucial role in voice message recognition. Distance measures characterizing phoneme distortions in speech reinforcement systems (SRS) are discussed in the paper. The analysis shows a need to complement the existing acoustic standards recommending an indirect estimation of intelligibility on the basis of modulation transfer function (MTF) measurements, with newly developed measures based on the linear predictive coding (LPC) approach related directly to distortion of representative speech elements.

  • Phosphate and Thiophosphate Biphenyl Analogs as Steroid Sulfatase Inhibitors
    • Sebastian Demkowicz
    • Witold Kozak
    • Mateusz Daśko
    • Maciej Masłyk
    • Konrad Kubiński
    • Janusz Rachoń
    2015 DRUG DEVELOPMENT RESEARCH

    In the present work, we report convenient methods for the synthesis and biological evaluation of phosphate and thiophosphate biphenyl derivatives exhibiting steroid sulfatase (STS) activity. The described synthesis is based on straightforward preparation of biphenyl-4-ol and 40-hydroxybiphenyl- 4-carboxylic acid ethyl ester modified with various phosphate or thiophosphate moieties. The inhibitory effects of these compounds were tested on STS isolated from human placenta and led to two compounds of interest, 5a and 5d with IC50 values of 28.0 and 22.1 mM, respectively and that had interesting new binding modes in the STS active site. Drug Dev Res 76 : 94–104, 2015.

  • Phospholipids as potential prevention factor in carcinogenesis
    • Karol Parchem
    • Agnieszka Bartoszek-Pączkowska
    2015 Acta Biochimica Polonica

    Phospholipids are a group of complex lipids, which can be used in cancer chemoprevention. Glicerophospholipids are composed of fatty acids esterified to a glycerol backbone, a phosphate group and a hydrophilic residue such as: cho- line, ethanoloamine, serine or inositol. In the sn-2 position of glicerophospholipid usually there are unsaturated fatty acids, i.e. linolenic acid, while in the sn-1 position more typi- cal are saturated fatty acids, i.e. palmitic acid. The second group of phospholipids are sphigophospholipids, in which amino-alcohol is build in instead of glycerol. For these two groups of phospholipids have been described preventive activities of carcinogenic processes. Fatty acids from n-3 family, such as eicosapentaenoic or docosahexaenoic ac- ids, which exhibit anti-inflammatory properties are better transported within human body as glicerophospholipids than as free fatty acids. Phospholipids probably have also inhibitory effect on metastasis of tumor cells. This fact is related to the construction of the cancer cell membrane where lipid rafts occur in high concentration. Cancer pa- tients often take non-steroidal anti-inflammatory drugs to decrease pain. Phospholipids can reduce negative impact of these drugs preventing gastrointestinal side effects. Health-promoting phospholipids can be found in some foodstuffs. High content of these lipids occurs in marine products, egg yolk, soybean products or milk. Phospholipids are now widely marketed in the form of dietary supplements. Because of the still unrecognized mechanism of action, as well as low toxicity and widespread occurrence in food, chemopreventive potential of phospholipids deserve more detailed investigations.

  • Photoconduction and magnetic field effect on photoconduction in hole-transporting star-burst amine (m-MTDATA) films
    • Daniel Karol Pelczarski
    • Piotr Jerzy Grygiel
    • Maciej Miśnik
    • Waldemar Stampor
    2015 ORGANIC ELECTRONICS

    Photoconduction and magnetic field effect on photoconduction have been investigated as a function of electric field strength, excitation light intensity and wavelength in vacuum evaporated films of m-MTDATA (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylylamino) triphenylamine), the starburst amine commonly used as hole-transporting material in organic light-emitting diodes. The photocurrent is found to be generated by the singlet exciton dissociation at the illuminated Al anode/m-MTDATA interface in accordance with the 1-D Onsager mechanism and in the bulk of the sample in terms of the 3-D Onsager model of e–h pair separation. The surface component of photocurrent is magnetic field independent whereas the bulk-generated photocurrent is influenced by external magnetic field of the hyperfine coupling (HFC) as well as fine structure modulation (FSM) scales.

  • Photoelectrochemical properties of BIMEVOX (ME=Cu, Zn, Mn) electrodes in contact with aqueous electrolyte
    • Konrad Trzciński
    • Anna Borowska-Centkowska
    • M. Sawczak
    • Anna Lisowska-Oleksiak
    2015 SOLID STATE IONICS

    Layered oxide Bi4O2O11 and mixed oxides of bismuth, vanadium and a third metal (ME = Cu, Zn, Mn) were synthesized and characterized using XRD, Raman and SEM. The energy band gap (Eg) of samples determined using UV–VIS reflectance spectra equals to 2.46, 2.34, 2.27 and 2.18 eV for Bi4V2O11, BICUVOX (Bi2V1 − xCuxO5.5 − 3x/2), BIZNVOX (Bi2V1 − xZnxO5.5 − 3x/2) and BIMNVOX (Bi2V1 − xMnxO5.5 − x/2) (x = 0.1), respectively. Open circuit voltage measurements confirmed the n-type semiconductor's activity for all the tested oxides. This work shows that all studied materials are active under UV and visible light illumination.

  • Photogrammetric Development Of The Threshold Water At The Dam On The Vistula River In Wloclawek From Unmanned Aerial Vehicles (Uav)
    • Jakub Szulwic
    • Marek Przyborski
    • Bogdan Szczechowski
    • Witold Szubiak
    • Tadeusz Widerski
    2015

    Barrage in Wloclawek (Poland) was designed by Hydroprojekt and built in the years of 1962 - 1970 as the first stage of the planned Lower Vist ula Cascade. Cascade design assumed the construction of 8 dams in Wyszogr o d, Plock, Wloclawek, Nieszawa (Ciechocinek as an option), Solec Kujawski, Chelmno, Opalen and Tczew. Nieszawa dam was supposed to ensure the maintenance of an adequate free surface of water below the right dam in Wloclawek. Lower Vistula Cascade was not built, and until nowadays the dammed role is realized by the water threshold downstream the dam in Wloclawek, in its immediate vicinity. This threshold is a subject of a particular co ncern and photogrammetric analysis, presented in the article. Technical aspects and condition of the water threshold are related to the stability of the dam on the Vistula River in Wloclawek. Currently, the investment process was launched and it is aimed t o change the development of Lower Vistula area. The investment realization is connected with the renovation of the dam on the Vistula River and it should help to change the role of the threshold in Wloclawek. At the same time, the awareness and qualitative evaluation of the threshold are required. Due to the difficulties in access to the threshold and the limited time of its unveiling, the photogrammetric method using Unmanned Aerial Vehicle (UAV) seemed to be effective and available for quick registration and validation of the threshold. The authors present the photogrammetric preparation which reflects the threshold condition. The realization was performed on the basis of 70 non - metric photos taken from the UAV. As part of the article, the technological p roblems and their solutions related to planning the run - in, as well as the description of the measurement method combining the photogrammetric and geodetic preparations (tachymeter measurement using TotalStation) are cited. The article includes the techni cal analysis of the enterprise and it indicates methods for the optimization of UAV use in the elaborations related to hydraulic engineering structures.

  • Photophysics of a Ruthenium 4H-Imidazole Panchromatic Dye in Interaction with Titanium Dioxide
    • Julian Schindler
    • Stephan Kupfer
    • Maria WäCHTLER
    • Julien Guthmuller
    • Sven Rau
    • Benjamin Dietzek
    2015 CHEMPHYSCHEM

    The photophysics of bis(4,4′-di-tert-butyl-2,2′-bipyridine-κ2N,N′)[2-(4-carboxyphenyl)-4,5-bis(p-tolylimino-κN)imidazolato]ruthenium(II) hexafluorophosphate is investigated, both in solution and attached to a nanocrystalline TiO2 film. The studied substitution pattern of the 4H-imidazole ligand is observed to block a photoinduced structural reorganization pathway within the 4H-imidazole ligand that has been previously investigated. Protonation at the 4H-imidazole ring decreases the excited-state lifetime in solution. When the unprotonated dye is anchored to TiO2, photoinduced electron injection occurs from thermally nonrelaxed triplet metal-to-ligand charge transfer (3MLCT) states with a characteristic time constant of 0.5 ps and an injection efficiency of roughly 25 %. Electron injection from the subsequently populated thermalized 3MLCT state of the dye does not take place. The energy of this state seems to be lower than the conduction band edge of TiO2.

  • Photophysics of Ru(II) Dyads Derived from Pyrenyl-Substitued Imidazo[4,5-f][1,10]phenanthroline Ligands.
    • Christian Reichardt
    • Mitch Pinto
    • Maria Wachtler
    • Mat Stephenson
    • Stephan Kupfer
    • Tariq Sainuddin
    • Julien Guthmuller
    • Sherri A. Mcfarland
    • Benjamin Dietzek
    2015 JOURNAL OF PHYSICAL CHEMISTRY A

    The photophysics of a series of Ru(II) dyads based on the 2-(1-pyrenyl)-1H-imidazo[4,5-f][1,10]-phenanthroline ligand was investigated. The ability of these metal complexes to intercalate DNA and induce cell death upon photoactivation makes them attractive photosensitizers for a range of photobiological applications, including photodynamic therapy. In the present study, time-resolved transient absorption and emission spectroscopy were used to interrogate the photoinduced processes that follow metal-to-ligand charge transfer excitation of the complexes in solution. It was found that energy transfer to pyrene-localized intraligand triplet states, facilitated by torsional motion of the pyrene moiety relative to the imidazo[4,5-f][1,10]phenanthroline ligand, was an important relaxation pathway governing the photophysical dynamics in this class of compounds. Biphasic decay kinetics were assigned to spontaneous (pre-equilibrium) and delayed emission, arising from an equilibrium established between (3)MLCT and (3)IL states. TDDFT calculations supported these interpretations.