2015 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2015

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Experience-Driven Model of Decision-Making Processes in Project Teams
- Cezary Orłowski
- Arkadiusz Sarzyński
- Tomasz Sitek
- Artur Ziółkowski
2015 CYBERNETICS AND SYSTEMS
This article presents a model of decision-making processes in project teams. Project teams constitute a specific type of organization appointed to implement a project. Decisions made by project teams result from the methods of project management and best management practices. The authors have undertaken the task of formalizing these processes using the classical method of constructing decision trees. It has been established that this method cannot be fully exploited because the decision-making paths need changing (the decision tree must be dynamically generated after every decision). Therefore, the authors applied a method for collecting experiences, the Set of Experience Knowledge Structure (SOEKS), to support the structure of a decision tree. This method was used to support decision-making processes regarding the selection of methods and technologies of project management and to classify the location decisions resulting from exceeding levels of particulate matter.
Experimental and Numerical Study on Pounding of Structures in Series
- Saher El-Khoriby
- Ayman Seleemah
- Hytham Elwardany
- Robert Jankowski
2015
Pounding between structures in series during earthquakes may cause serious damage in the structural elements. The aim of this paper is to show the results of an experimental and numerical study that is focused on pounding between more than two structures which may be described as “structures in series”. In this study, the shaking table experiments, as well as the numerical analyses, were performed using three tower models including rigid and flexible structures with different configurations and different gap distances under several earthquake excitations. The results show that pounding may affect the behaviour of the structures significantly. They also indicate that the rigid towers are more influenced by pounding than the flexible ones. Moreover, increasing or decreasing the gap distance may lead to increase or decrease in the response under different earthquakes with no specific trend. Furthermore, the optimal gap size has been found to be either the distance which prevents pounding or the zero gap.
Experimental bases for the rail track surface damage detection system
- Julian Kominowski
- Roksana Licow
2015 Journal of Mechanical and Transport Engineering
A diagnosis of rail surface is generally based on the classical method of direct assessment and track geometry measurements. Identification and qualification of inequality and damage on the surface rails is depend on the skills and experience person who conducting inspection. In times of increasing exploitation of railways, infrastructure managers decide to use systems supporting the assessment of technical condition of the railways. In order to improve efficiency of detecting and maintaining uniform assessment criteria developed systems for detecting and monitoring inequalities damage on the surface rails. This article presents the assumption being the basis of the experimental monitoring system dedicated to the Polish railway infrastructure manager. The foundation of the research will be measurement and analysis of the dynamic response of the selected railway vehicle. The functional requirements and the actual research methodology on selected section of the main railway line have been discussed. The paper presents architecture of measurement subsystem installed on typical type passenger electric locomotive. The implementation of a method for assessing in existing monitoring system has been proposed.
Experimental comparison of hydrodynamic thrust bearings with different pad surface materials
- Michał Wodtke
2015
Babbitt is the material most frequently used as the pad surface material for hydrodynamic bearings operating at usual operating conditions. It shows many advantages important for safe bearing operation, as for example: low friction coefficient, corrosion resistance, fair mechanical properties and outstanding conformability. On the other hand, it is not free from disadvantages, such as limited fatigue strength or limited resistance to high temperatures. It has become clearly visible that, especially in case of severe operating conditions, bearings with polymer based coatings (based mainly on PTFE or PEEK) showed better performance. Both types of lining (polymer and babbitt) differ significantly comparing their material properties, which has also an influence on bearing behaviour. The results of experimental tests carried out on an eight-pad thrust bearing with babbitt and PEEK surface materials are presented. Tests were completed with the use of the unique test rig possessed by Gdansk University of Technology which allowed to carry out tests of bearings under typical operating conditions for many bearing applications. During the tests, pad and collar temperatures, bearing friction torque and pad tilt were recorded. Comparison of the results highlighted differences in the behaviour of the bearings with the same dimensions and different pad surface materials.
Experimental research on water lubricated three layer sliding bearing with lubrication grooves in the upper part of the bush and its comparison with a rubber bearing
- Wojciech Litwin
2015 Pełny tekst TRIBOLOGY INTERNATIONAL
composite. Eachofitslayershasanimportantfunction.Speciallypreparedslidingsurfaceensures minimum resistance.Followingrunning-initssmoothnessbecomesveryhighandthebearingmay continue workingunder fluid lubricationregime.NBRlayerensuresbearingelasticity,goodvibration damping propertiesandinsusceptibilitytoshaftaxismisalignment.Theexternalbrasslayermakes fitting thebearingeasier. Experiment resultsoftheconductedresearchwerecomparedwiththoseforarubberbearingof similar geometry.
Experimental Study on Pounding between Structures during Damaging Earthquakes
- Robert Jankowski
- Ayman Seleemah
- Saher El-Khoriby
- Hytham Elwardany
2015 Key Engineering Materials
Mutual pounding between structures during earthquakes may cause serious structural damage. The aim of this paper is to show the results of a shaking table experimental study focused on pounding between structures in series under several earthquake excitations. The experiments were performed using three tower models with different configurations and different gap distances between them. In the first stage of the study, one rigid tower was installed between two flexible structures, while later on, the flexible tower was located between two rigid structures. The results of the study show that pounding observed during damaging earthquakes might affect the behaviour of structures significantly. It was observed that the rigid towers are more influenced by pounding than the flexible structures. Moreover, the optimal gap size was found to be either the distance which prevents pounding (and therefore prevents from damage) or the zero gap.
Experimental Study on Steel Tank Model Using Shaking Table/ Badania Eksperymentalne Modelu Zbiornika Stalowego Na Stole Sejsmicznym
- Daniel Burkacki
- Robert Jankowski
2015 Pełny tekst Civil and Environmental Engineering Reports
Stalowe zbiorniki walcowe są bardzo popularnymi konstrukcjami używanymi do magazynowania produktów przemysłu chemicznego i naftowego. Ich bezpieczeństwo i niezawodność są kluczowe, ponieważ każde uszkodzenie może nieść za sobą bardzo poważne konsekwencje. Trzęsienia ziemi są najbardziej niebezpiecznymi, a zarazem najbardziej nieprzewidywalnymi obciążeniami dynamicznymi, które mogą oddziaływać na tego typu konstrukcje. Z drugiej strony ruchy podłoża związane ze wstrząsami górniczymi są uważane za mniej groźne z powodu osiągania niższych poziomów wartości przyspieszeń. Celem niniejszego artykułu jest przedstawienie wyników badań eksperymentalnych, które przeprowadzono na wykonanym w skali modelu rzeczywistego zbiornika zlokalizowanego na terenie Polski. Badania wykonano przy użyciu stołu sejsmicznego. Zakres badań obejmował testy harmoniczne właściwości dynamicznych oraz zachowanie się stalowego zbiornika walcowego podczas trzęsień ziemi oraz wstrząsów górniczych dla różnych poziomów wypełnienia cieczą. Wyniki badań pokazują, że produkt magazynowany może mieć znaczący wpływ na wartości parametrów dynamicznych oraz potwierdzają, iż poziom wypełnienia cieczą jest istotny w analizie konstrukcji. Porównanie odpowiedzi podczas trzęsień ziemi oraz wstrząsów górniczych wskazuje, iż to drugie wymuszenie może być w niektórych przypadkach bardziej niekorzystne.
Experimental study on the effectiveness of polymer damper in damage reduction of temporary steel grandstand
- Natalia Lasowicz
- Arkadiusz Kwiecień
- Robert Jankowski
2015 Pełny tekst Journal of Physics : Conference Series
A large number of accidents, involving collapses of temporary grandstands during different types of events, were observed in the past. If the synchronized movement of people is tuned with the natural frequency of the affected part of the structure, resonance might occur. It may lead to severe damages of grandstands, their collapse or panic among the spectators. The aim of the paper is to assess, through preliminary experimental tests, the effectiveness of a polymer damper in damage reduction of a temporary steel grandstand. The damper considered in the study has been constructed out of two L-shape steel members bonded with polymer mass of high damping properties. The element has been installed as a diagonal one at the back part of the structure. The method has been compared with the typical solution of strengthening the grandstand with the diagonal stiffener of tubular cross section. The results of the study show that the responses of a temporary steel grandstand equipped with the polymer damper as well as with the typical stiffener are substantially different. The application of the polymer damper leads to the substantial increase in the level of structural damping ratio allowing to minimize the possibility of structural damage.
Experimental Testing of Innovative Cold-Formed "GEB" Section / Badania Eksperymentalne Innowacyjnego Kształtownika Giętego Na Zimno Typu „Geb“
- Agnieszka Łukowicz
- Elżbieta Urbańska-Galewska
- Małgorzata Gordziej-Zagórowska
2015 Pełny tekst Civil and Environmental Engineering Reports
One of the major advantages of light gauge steel structures made of cold-formed steel sections is their low weight, so manufacturers are increasingly using the possibilities of those sections for the production of typical single-storey steel structures systems. Well known profiles, such as Z, C and the so called hat sections that have been studied and described in the literature, are used mainly as purlins or truss components. A new profile GEB was patented and it may serve as primary load-bearing members in fabricated steel frames. According to the code [1] every new section shape should be tested to assign the cross sectional deformation behaviour and capacity, hence this profile inter alia was tested for three point loading. The paper reports the results of this experimental investigation and also computational analysis in MARC MANTAT e.g. deformation modes and values of maximum load. Simultaneously, values of cross-section capacity were assigned based on codes [1, 2].
Exploration of optical fibres as a carrier for new benzene and toluene matrix-free reference materials
- Marta Słomińska
- Mariusz Marć
- Jolanta Szczygelska-Tao
- Piotr Konieczka
- Jacek Namieśnik
2015 Pełny tekst ANALYTICAL AND BIOANALYTICAL CHEMISTRY
To meet high expectations concerning precision and accuracy of reference materials, preparation of matrixfree reference materials using thermal decomposition-gas chromatography-mass spectrometry (TD-GC-MS) was proposed in this study. In the paper, the results obtained in preparation of the new reference materials for benzene and toluene are presented, based on the thermal decomposition technique of compounds chemically bound to the surface of optical fibre segments. The results obtained at various stages of the research procedure (homogeneity, stability) confirmed the possibility of using prepared laboratory samples of materials as reference materials for benzene and toluene. For the prepared batch of materials, reference values 1.26±0.91 (ng/fibre) for benzene and 11.3±7.4 (ng/fibre) for toluene were determined.
Exploring governance among social co-operatives: three models from Poland
- Marzena Starnawska
2015 Social Sciences/ Socialiniai Mokslai
There has been overly interest regarding social enterprise and social entrepreneurship in theory and practice. In this paper the author introduces the workings of governance of small social enterprises i.e. social co-operatives, acting in most cases for the purpose of work and social integration of the marginalized, at the bottom of the pyramid of socio-economic system. The aim of this paper is to provide insights into under researched topic of governance among social co-operatives, which have become a unique breed in social enterprise and co-operative landscape in Poland since 2007. Having collected vast amount of data through in-depth interviews with social co-operative members and founders, observation, and participation to the meetings in organizations supporting social enterprise in Pomeranian province1, the author employs descriptive and exploratory case analysis of 5 social cooperatives. Because of the space constraints only selected data are presented in the paper. The author proposes three models of social co-operative governance types: ‘small democratic community’, ‘business providing jobs’ and ‘integrated family like’.
Export diversification and economic development: a dynamic spatial data analysis
- Roberto Basile
- Aleksandra Parteka
- Rosanna Pittiglio
2015 Gecomplexity Discussion Papers
This paper contributes to the empirical literature on the relationship between â€˜export varietyâ€™ (export diversification) and economic development by relaxing the assumption of cross-country independence and allowing for spatial diffusion of shocks in observed and unobserved factors. Export variety is measured for a balanced panel of 114 countries (1992-2012) using very detailed information on their exports (HS 6-digit product level). The estimation results of a dynamic spatial panel data model confirm the relevance of spatial network effects: indirect effects (spatial spillovers) strongly reinforce direct effects, while spatial proximity to large countries accelerates the diversification process. These results are robust to the choice of the weights matrix (an inverse-distance matrix, an exponential distance matrix and a matrix based on bilateral trade flows are used).
Expression of goose parvovirus whole VP3 protein and its epitopes in Escherichia coli cells
- Tarasiuk Karolina
- Woźniakowski Grzegorz
- Lucyna Holec-Gąsior
2015 Pełny tekst POLISH JOURNAL OF VETERINARY SCIENCES
The aim of this study was the expression of goose parvovirus capsid protein (VP3) and its epitopes in Escherichia coli cells. Expression of the whole VP3 protein provided an insufficient amount of protein. In contrast, the expression of two VP3 epitopes (VP3ep4, VP3ep6) in E. coli, resulted in very high expression levels. This may suggest that smaller parts of the GPV antigenic determinants are more efficiently expressed than the complete VP3 gene.
Extended Reflexive Ontologies for the Generation of Clinical Recommendations
- Eider Sanchez
- Carlos Toro
- Manuel Graña
- Cesar Sanin
- Edward Szczerbicki
2015 CYBERNETICS AND SYSTEMS
Decision recommendations are a set of alternative options for clinical decisions (e.g., diagnosis, prognosis, treatment selection, follow-up, and prevention) that are provided to decision makers by knowledge-based Clinical Decision Support Systems (k-CDSS) as aids. We propose to follow a ‘‘reasoning over domain’’ approach for the generation of decision recommendations by gathering and inferring conclusions from production rules. In order to rationalize our approach, we present a specification that will sustain the logic models supported in the knowledge bases we use for persistence. We introduce first the underlying knowledge model and then the necessary extensions that will convey toward the solution of the reported needs. The starting point of our approach is the proposition of Reflexive Ontologies (RO). Here, we go a step further, proposing an extension of RO that includes the handling and reasoning that production rules provide. Our approach speeds up the recommendation generation process.
Exterior Plasterwork in Gdynia`s Modernist Architecture and Its Preservation
- Robert Hirsch
2015
Text presents the historical plasterworks of facades of modernist monuments built before WWII as the important expression in architecture and ist conservation
Eye tracking within near-to-eye display
- Tomasz Kocejko
- Jacek Rumiński
- Jerzy Wtorek
- Benoit Martin
2015
In this paper we investigate the effectiveness of the gaze interaction within near-to-eye display. The practical aspect of the paper is about combining an eye tracker with smart glasses. Presented research is related with the eGlasses project, which is focused on the development of an open platform in the form of multisensory electronic glasses and related interaction methods. One of the implemented interaction methods is the one based on eye tracking module. Both, the advantages and limitation of the method are discussed. We also considering the calibration free method of fixation points estimation within the near-to-eye display.
Fabrication and properties of electrode material composed of ordered titania nanotubes and pEDOT:PSS
- Katarzyna Siuzdak
- Mirosław Sawczak
- Anna Lisowska-Oleksiak
2015 SOLID STATE IONICS
We report on the two-stage preparation method of electrode material composed of titania nanotubes and poly(3,4-ethylenedioxythiopene):poly(2-styrenesulphonate) conductive polymer (pEDOT:PSS). Initially, titania nanotube arrays were produced by the anodization process of Ti substrate. Next, the polymer was potentiostatically deposited onto the thermally annealed nanotube arrays from the electrolyte containing monomer and counter ion. The obtained material was characterized by means of Raman spectroscopy, SEM and photoluminescence spectroscopy. On the basis of electrochemical studies, a radical decrease in the electrode material resistance after conductive polymer deposition was detected. The enhancement in registered current under UV–vis irradiation was almost 4 times higher for a composite with the highest amount of deposited pEDOT:PSS in comparison to pristine titania nanotube array film.
Fabrication of Composite Polyurethane/Hydroxyapatite Scaffolds Using Solvent-Casting Salt Leaching Technique
- Joanna Wosek
2015 Pełny tekst Advances in Materials Science
Scaffolds are porous three-dimensional structures which are used to fill bone losses and make them possible to cells to grow. Many different structural and biological properties are required from them: porosity, mechanical strength and biocompability. The present research is aimed at development of composite polyurethane/hydroxyapatite scaffolds by using the solvent-casting salt leaching method. The SEM examinations were applied to assess the structure of obtained scaffolds.
Fabrication of polyurethane and polyurethane based composite fibers by the electrospinning technique for soft tissue engineering of cardiovascular system
- Justyna Kucińska-Lipka
- Iga Gubańska
- Helena Janik
- Maciej Sienkiewicz
2015 Materials Science & Engineering C-Materials for Biological Applications
Electrospinning is the unique technique, which provides forming of polymeric scaffolds for soft tissue engineering, which include tissue scaffolds for soft tissues of cardiovascular system. Such artificial soft tissues of cardiovascular system may possess mechanical properties comparable to native vascular tissues. Electrospinning technique gives the opportu nity to form fibres with nm- to μm-scale in diameter. The arrangement of obtained fibres and their surface determines the biocompatibility of the scaffolds. Polyurethanes (PU)s are being commonly used as a prostheses of cardiovascular soft tissues due to their excellent biocompatibility, non-toxicity, elasticity and mechanical properties. PUs possess also fine spinning properties. The combination of PU properties variety with an electrospinning technique, conducted at the well tailored conditions, gives unlimited possibilities of forming novel polyurethane materials suitable for soft tissue scaffolds applied in cardiovascular tissues engineering. This paper can help researches to gain more widespread and deeper understanding of designing electrospinable PU materials, which may be used as cardiovascular soft tissue scaffolds. In this paper we focus on reagents used in PU synthesis designed to increase PUs biocompatibility (polyols) and biodegradability (isocyanates). We also describe suggested surface modifications of electrospun PUs, and the direct influence of surface wettability on providing enhanced biocompatibility of scaffolds. We indicate a great influence of electrospinning parameters (voltage, flow rate, working distance) and used solvents (mostly DMF, THF and HFIP) on fibres alignment and diameter - what impacts the biocompatibility and hemocompatibility of such electrospun PU scaffolds. Moreover, we present PU modifications with natural polymers with novel approach applied in electrospinning of PU scaffolds. This work may contribute with further developing of novel electrospun PUs, which may be applied as soft tissue scaffolds of cardiovascular system.
Face Profile View Retrieval Using Time of Flight Camera Image Analysis
- Piotr Bratoszewski
- Andrzej Czyżewski
2015
Method for profile view retrieving of the human face is presented. The depth data from the 3D camera is taken as an input. The preprocessing is, besides of standard filtration, extended by the process of filling of the holes which are present in depth data. The keypoints, defined as the nose tip and the chin are detected in user’s face and tracked. The Kalman filtering is applied to smooth the coordinates of those points which can vary with each frame because of the subject’s movement in front of the camera. Knowing the locations of keypoints and having the depth data the contour of the user’s face a profile retrieval is attempted. Further filtering and modifications are introduced to the profile view in order to enhance its representation. Data processing enhancements allow emphasizing minima and maxima in the contour signals leading to discrimination of the face profiles and enable robust facial landmarks tracking.