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Repozytorium publikacji
Politechniki Gdańskiej

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Publikacje z roku 2015

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  • Model of pressure distribution in vortex flow controls
    • Mielczarek Szymon
    • Jerzy Sawicki
    • Szymon Mielczarek
    2015 Pełny tekst Archives of Hydro-Engineering and Environmental Mechanics

    The paper is devoted to the vortex valve. Existing devices are described by CFD-methods, or by means of simple empirical relations. A rational method of the considered object design is proposed, on the base of the input and dissipation energy balance., what gives a simple algebraic equation. Conformity between calcul;ated and measured parameters of the vortex valve allows for acceptation of the proposed concept.

  • Model of the hydraulic pump powertrain of refuse collection vehicle compaction mechanism
    • Jacek Czyżewicz
    • Jacek Kropiwnicki
    • Oskar Wysocki
    2015 Pełny tekst Combustion Engines

    W pracy przedstawiono symulację pracy układu napędowego pompy hydraulicznej mechanizmu prasującego śmieciarki oraz wpływ różnych konfiguracji elementów składowych tego urządzenia na zużycie paliwa silnika napędowego w warunkach przyjętego cyklu obciążenia. W tym celu wykorzystano model układu napędowego pompy hydraulicznej mechanizmu prasującego śmieciarki w formie grafów wiązań oraz wyniki pomiarów ciśnienia roboczego w siłownikach hydraulicznych mechanizmu prasującego w trakcie wybranych cykli pracy przeprowadzonych na śmieciarce firmy Ekocel. Uzyskane wyniki umożliwiły określenie optymalnej wartości przełożenia przekładni umieszczonej między silnikiem napędowym i pompą hydrauliczną ze względu na przyjęte kryterium minimalizacji zużycia paliwa.

  • Model Order Reduction for Problems With Dispersive Surface Boundary Conditions
    • Michał Rewieński
    • Adam Lamęcki
    • Michał Mrozowski
    2015 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS

    This letter proposes a new scheme for reduced-order finite-element modeling of electromagnetic structures with nonlinear, dispersive surface boundary conditions, which optimally exploits the numerically stable and efficient MOR framework for second-order systems provided by SAPOR method. The presented results of numerical experiments for an example of a waveguide filter demonstrate the superior accuracy of the resulting reduced models both locally, around the expansion point, and over a wide frequency band, as compared to other commonly used methods for approximating the dispersive boundary conditions

  • Model szyny integracyjnej danych i ontologii procesów Smart Cities
    • Cezary Orłowski
    • Tomasz Sitek
    • Artur Ziółkowski
    • Paweł Kapłański
    • Aleksander Orłowski
    • Witold Pokrzywnicki
    2015 Pełny tekst Przedsiębiorstwo we współczesnej gospodarce - teoria i praktyka

    W artykule przedstawiono propozycję modelu szyny integracyjnej wykorzystywanego w projektowaniu architektur systemów Smart Cities. Model takiej szyny staje się niezbędny przy projektowaniu architektur wysokopoziomowych (ang. high level architecture), w ramach których procesy silosowe organizacji powinny być widziane z pespektywy jej ontologii. Aby taka szyna mogła być wykorzystywana przez dowolne miasta zaproponowano rozwiązanie generyczne, które może być implementowane w całości lub części w zależności od wymagań miast stawianych w stosunku do konstrukcji takich szyn.Praca została podzielona na cztery główne części. W części pierwszej został przedstawiony model procesów projektowania architektury wysokopoziomowej z wykorzystaniem ontologii i szyny integracyjnej danych, który jest uogólnieniem doświadczeń autorów wyniesiony z procesów projektowania systemów Smart Cities. Część druga zawiera opis środowiska wytwarzania systemów Smart Cities zobrazowany dwoma wytycznymi oraz procesami implementacji tych wytycznych. W części trzeciej wyodrębniono dwie składowe stanu tego środowiska: szynę integracyjną danych oraz ontologii procesów miasta dla zobrazowania sposobu projektowania systemów Smart Citeis i pokazania procesów przenikania się danych i ontologii procesów miasta w budowie architektury wysokopoziomowej. Część czwarta zawiera opis zastosowania proponowanego modelu do budowy wspólnej szyny integracyjnej danych i ontologii. Artykuł podsumowują rekomendację dotyczące możliwości zastosowania proponowanego modelu.

  • Modele biznesów jako nowy obszar badań w naukach o zarządzaniu
    • Bogdan Nogalski
    • Tadeusz Falencikowski
    2015

    Prowadzone od jakiegoś czasu badania modeli biznesu oraz zbliżająca się 15 rocznica pojawienia się tego zagadnienia w Polsce stały się impulsem do podjęcia próby podsumowania dotychczasowych głównych obszarów badań oraz nakreślenia kierunków dalszych prac eksploracyjnych. Określono cztery nurty dotychczasowych badań modeli biznesu: definiowanie i struktura modelu biznesu, typologia modeli biznesów, innowacyjność modeli biznesów oraz relacja model biznesu – strategia. W zakresie pierwszego nurtu opisano zagadnienie definiowania oraz wyłoniono strukturę modelu biznesu. W drugim nurcie po omówieniu licznych ujęć rodzajowych wskazano na dwa istotne cele – komercyjny i naukowy – formułowania modelu biznesu. W przypadku celu naukowego konieczne jest inne, staranniejsze i bardziej wszechstronne podejście. Charakteryzując trzeci nurt, innowacje modelu biznesu ujęto pojęciowo i rodzajowo oraz zaznaczono wartości dla klientów i nie-klientów jako podstawę innowacyjności modeli biznesu dodając, że sukces daje pakiet innowacji. W ostatnim nurcie badań wskazano, że model biznesu i strategia biznesu to dwa ontologiczne indywidua, które łączą silne związki zgodności celowej i kompatybilności. Analiza relacji uprzedniości – następczości umożliwiła wskazanie, że na osi czasu trwania biznesu model biznesu poprzedza strategię biznesu. W końcowej części opracowania sformułowano propozycję dalszych kierunków prac, takich jak badanie: elementów oceniających model biznesu, sfery aksjologicznej modeli biznesu, modelu biznesu sieci przedsiębiorstw, rodzajów i siły relacji wewnętrznych i zewnętrznych modeli biznesu, miejsca i roli modelu biznesu w zarządzaniu strategicznym.

  • Modeling bioaugmentation with nitrifiers in membrane bioreactors
    • Alberto Mannucci
    • Giulio Munz
    • Gualtiero Mori
    • Jacek Mąkinia
    • Claudio Lubello
    • Jan A. Oleszkiewicz
    2015 WATER SCIENCE AND TECHNOLOGY

    Bioaugmentation with nitrifiers was studied using two pilot-scale membrane bioreactors, with the purpose of assessing the suitability of state-of-the-art activated sludge models (ASMs) in predicting the efficiency of bioaugmentation as a function of operating conditions. It was demonstrated that the temperature difference between seeding and seeded reactors (ΔT) affects bioaugmentation efficiency. Experimental data were accurately predicted when ΔT was within a range of up to 10 °C at the higher range, and when the temperature was significantly lower in the seeded reactor compared to the seeding one, standard ASMs overestimated the efficiency of bioaugmentation. A modified ASM, capable of accurately representing the behavior of seeded nitrifying biomass in the presence of high ΔT, would require the inclusion of the effect of temperature time gradients on nitrifiers. A simple linear correlation between ΔT and the Arrhenius coefficient was proposed as a preliminary step.

  • Modeling emotions for affect-aware applications
    • Agata Kołakowska
    • Agnieszka Landowska
    • Mariusz Szwoch
    • Wioleta Szwoch
    • Michał Wróbel
    2015

    The chapter concerns emotional states representation and modeling for software systems, that deal with human affect. A review of emotion representation models is provided, including discrete, dimensional and componential models. The paper provides also analysis of emotion models used in diverse types of affect-aware applications: games, mood trackers or tutoring systems. The analysis is supported with two design cases. The study allowed to reveal, which models are most intensively used in affect-aware applications as well as to identify the main challenge of mapping between the models.

  • Modeling N2O behavior during denitrification with different carbon sources and electron acceptors
    • Kamil Wiśniewski
    • Maciej Kowalski
    • Benjamin Vogel
    • Maike Beier
    • Krzysztof Czerwionka
    • Jacek Mąkinia
    2015

    A mathematical model was developed for identification of the most important mechanism leading to nitrous oxide (N2O) accumulation in denitrifying activated sludge systems. The activated sludge model No. 2d (ASM2d) was extended to include intermediate three steps of the denitrification process. The formation and accumulation of nitric oxide (NO) was assumed to be very low in the performed laboratory experiments. These experiments focused on the combined effects of different electron acceptors (nitrite, nitrate) and with different types of external carbon sources (acetate, ethanol) on the behaviors of polyphosphate accumulating organisms (PAOs) and “ordinary” heterotrophs. The accumulation of N2O was noticeable when the ratio COD/N ratio was low resulting in the limitation of N2O reductase activity. Nevertheless, during the test with ethanol and nitrate no accumulation of N2O was observed. Modeling results confirmed that high nitrite (NO2) concentrations caused inhibition of the nitrous oxide reductase (N2OR) activity leading to high accumulation of N2O. The proposed expanded model ASM2d accurately described the experiments and it could be used to estimate N2O emission during the denitrification process.

  • Modeling of event trees for the rapid scenario development
    • Mirosław Gerigk
    2015

    The paper concerns the safety of ships in abnormal/damage conditions. Some conclusions following from the research associated with development of a method for safety assessment of ships in abnormal/damage conditions is presented in the paper. The method called SSAMADC (Ship Safety Assessment Method in Abnormal/Damage Conditions) is a risk-based method and is connected with application of the quantitative risk assessment QRA approach. The method is an alternative method of safety assessment of ships in abnormal/damage conditions in comparison with the method included within the SOLAS 2009 regulations. The aim of the research is to work out a proposal of an alternative method of safety assessment of ships in damaged conditions. There is a lack of such the method for the certain type of ships.

  • Modeling of multi-cavity Fabry-Perot optical fiber sensors
    • Paweł Wierzba
    2015

    Reflectance characteristics of a two-cavity extrinsic Fabry-Perot optical fiber sensor were investigated using computer modeling. Calculations were performed using a plane wave-based approach, selected for clarity of results. Based on the modeling results, it can be concluded that the two-cavity Fabry-Perot interferometer can be used to measure two different quantities, such as refractive index and temperature, independently. It is also possible to use one of its cavities as a wavelength or optical path length reference, especially when a tunable laser is used as a light source. Spectral signal processing needed in such sensor is not substantially more complicated than that used in single cavity sensors.

  • Modeling of performance and safety of a multi-task unmanned autonomous maritime vehicle = Modelowanie ruchu i bezpieczeństwa wielozadaniowego bezzałogowego autonomicznego pojazdu wodnego
    • Mirosław Gerigk
    2015 Pełny tekst Journal of KONBiN

    At the beginning of the paper the aim of research is presented. Then the method is introduced. Next, the unmanned autonomous maritime vehicle is briefly described. The following chapter concerns a model of vehicle performance including the ballasting and motion. Some information on an integrated steering, positioning and stabilization system of the vehicle is briefly presented in the paper. Such the system enables to obtain a fully autonomous vehicle. In the final part of the paper some issues connected with the risk assessment and assessment of the vehicle safety are introduced.

  • Modeling of traffic safety indictors on Polish national road network
    • Wojciech Kustra
    • Marcin Budzyński
    • Kazimierz Jamroz
    • Joanna Żukowska
    2015

    Although decreased from 2001 to 2013, Poland’s road deaths improved at a slower rate than the rest of the EU, leaving Poland as one of the worst road safety performing countries in the EU. The national road network in Poland, despite the dynamic transformation and development, still does not conform to the EU safety standards. Similar situation exists in other EU countries, particularly those in Central and Eastern Europe. Safety standards for road infrastructure show considerable differences in terms of structure and scope. It is necessary to develop new procedures for performing road inspections as the main tool for risk assessment in traffic. The starting point for this should be the analysis of the relationship between the sources of hazard on the road, and the personal and economic consequences of road accidents. The authors of this paper using mathematical models will describe these relationships. The aim of these models is to simulate the effect of a set of different sources of hazards on the number accidents and their consequences on the selected sections of national road network in Poland

  • Modeling the Effects of Slowly Biodegradable Substrate at Large WWTP in Northern Poland
    • Jakub Drewnowski
    • Jacek Mąkinia
    2015

    The essential study was divided into two parts: experimental investigation and mathematical modeling using special platform to computer simulations. In the first part of research an innovative measurement procedure for an indirect determination of the effect of biodegradable particulate and colloidal Xs substrate was developed and implemented. The results of laboratory tests were used futher to verify the mechanism of the hydrolysis process using an existing IWA model ASM2d. Based on the concept “dual hydrolysis model” a new mathematical model in the combined N-P activated sludge systems was developed as the modified version of ASM2d during the study at “Wschod” WWTP in Gdansk (Poland) and presented in detail elsewhere. This paper contains further results obtained at a recently upgraded “Debogorze” WWTP in Gdynia under transient conditions (fall and spring sessions). The aim of this study was verified and compared of the newly developed two-step hydrolysis model of Xs called “modified ASM2d” at second large BNR plant in northern Poland.

  • Modelling of concrete behaviour in uniaxial compression and tension with DEM.
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2015 Pełny tekst GRANULAR MATTER

    W artykule omowiono wyniki modelowania betonu podczas jednoosiowego sciskania i rozciagania stosujac metode elementów dyskretnych. Beton zostal opisany jako material 3-fazowy (kruszywo, zaprawa cementowa i strefy kontaktu). Szczegolna uwage zwrocono na zjawiska mikro-strukturalne na poziomie kruszywa (lancuchy sil, wiry, obroty ziaren). Wyniki numeryczne zostaly porownano z wynikami badan doswiadczalnych.

  • Modelling of concrete facture at aggregate level using DEM based on x-ray mu CT images of internal structure
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2015 Photonics and Nanostructures-Fundamentals and Applications

    W artykule pokazano wyniki dyskretne DEM dla pękania betonu poddanego zginaniu. Beton został symulowany jako ośrodek 4-fazowy. Mikrostrukturę betonu określono na podstawie zdjęć uzyskanych mikro-tomografem. Szczególną uwagę zwrócono na zjawiska mikrostrukturalne podczas zarysowania na poziomie kruszywa.

  • MODELLING OF CONCRETE FRACTURE AT AGGREGATE LEVEL USING DEM BASED ON X-RAY mu CT IMAGES OF INTERNAL STRUCTURE
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2015

    The paper describes two-dimensional meso-scale numerical results of fracture in notched concrete beams under quasi-static three-point bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones (ITZs) and air voids. As a numerical approach, the discrete element method (DEM) was used. The concrete micro-structure in calculations was directly taken from real concrete specimens based on 3D x-ray micro-computed tomography images and 2D images by the scanning electron microscope (SEM). Attention was paid to the shape of a fracture zone between aggregate grains. In addition, the effect of properties of ITZs on fracture was studied.

  • Modelling of concrete fracture at aggregate level using FEM and DEM based on X-ray uCT images of internal structure
    • Łukasz Skarżyński
    • Michał Nitka
    • Andrzej Tejchman-Konarzewski
    2015 Pełny tekst ENGINEERING FRACTURE MECHANICS

    Artykuł podejmuje problem pękania w zginanych belkach betonowych. Proces pękania był obserwowany przy zastosowaniu mikrotomografii . Zaobserwowany proces był symulowany numerycznie przy zastosowaniu metody elementów skończonych i metody elementów dyskretnych. Beton był opisany jako materiał 4-fazowy. Otrzymano dobrą zgodność wyników numerycznych z doświadczalnymi.

  • Modelling of Different Aeration Modes Influencing Processes in SBR Bioreactor
    • Katarzyna Jaromin-Gleń
    • Adam Piotrowicz
    • Jakub Drewnowski
    • Grzegorz Łagód
    2015

    Currently, computer modelling together with the simulation tools tailored for that purpose constitute a very important element in planning technological changes within wastewater treatment plant. From the point of view of the WWTP operator every modification should be introduced in order to improve the quality of treated sewage with the lowest financial outlays. These requirements can be met by using computer programmes to effectuate the changes. In the research was performed the construction of computer model of the SBR reactor operating in laboratory scale. Technological data of the bioreactor as well as the data concerning wastewater quality indicators were entered into the GPS-X software package which was used as a simulation tool. The paper presents the simulation results of the 12-hour operation cycle which consisted of six phases: filling, mixing, aeration, settling, decanting and idle (excess sludge wasting). Simulation experiments were conducted in two variants differing in the aeration mode. In the first case the PID controller was used to maintain the dissolved oxygen concentration at constant level of 2 mgO2/L. In the latter case the oscillation of dissolved oxygen concentration during the aeration stage was applied. The oscillation effect was obtained by means of the appropriately elaborated set point of oxygen concentration taking into account specific intervals in oxygen supply. Consequently, the changes in dissolved oxygen concentration ranged between 0.5 and 2.5 mgO2/L. Among the two analysed variants the latter one with the oscillation of dissolved oxygen concentration proved to be more efficacious considering the quality of treated sewage and the electrical energy expenses. Results obtained after introduction of oscillation mode during aeration phase considerably improved the quality of effluent, especially in terms of dephosphatation process. Efficiency values for total phosphorous as well as orthophosphates removal increased significantly.

  • Modelling of Graphene Field-Effect Transistor for lectronic sensing applications
    • Maciej Łuszczek
    • Marek Turzyński
    • Dariusz Świsulski
    2015 Pełny tekst Przegląd Elektrotechniczny

    A top-gated Graphene Field-Effect Transistor (GFET) suitable for electronic sensing applications was modelled. The applied simulation method reproduces correctly the output transfer GFET characteristics and allows to investigate doping effect caused by different physical, chemical or biological factors. The appearance of additional charge in the system results in the shift of the current-voltage characteristic. This feature could be employed to measure the external factor intensity.

  • Modelling of the High Speed Multi-Pole Synchronous Generator for Application in More Electric Aircraft Power Systems
    • Michał Michna
    • Filip Kutt
    • Mieczysław Ronkowski
    2015

    In this paper different models of the synchronous generator are presented. The simulation results compared with the measurements are shown. Certain physical phenomena are included in described models for the porpoise of adequate analysis of the more electric aircraft power system. For different modelling levels, such as functional level or behavioural level, different physical phenomena have been included. Simulation results for simple functional level model and behavioural level model have been presented. The behavioural level model incorporates such physical phenomena as: magnetic saturation effect and the poliharmonic distribution of the air gap field. The models have been implemented into the Synopys/Saber software using the modelling language MAST. The carried out simulation and measured results have proved that the proposed approach can be recommended for analysis of MEA power systems.