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Gdańsk University of Technology

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Publications from the year 2013

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  • Ograniczanie ekspozycji na pola elektormagnetyczne - poziomy dopuszczalne, dozymetria
    • Tomasz Lisewski
    2013 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

    Równocześnie z poszukiwaniem zastosowań dla pól elektromagnetycznych prowadzone są badania wpływu pola na organizmy żywe. Jest to powodem wprowadzania ograniczeń ekspozycji. Dodatkowo prace nad technikami symulacyjnymi, modelami ciała ludzkiego oraz dostępność mocy obliczeniowe) sprawiają ze techniki komputerowe są wykorzystywane do oceny ekspozycji na pola elektromagnetyczne Przedstawiono wytyczne instytucji zajmujących się tematyką ekspozycji na pola elektromagnetyczne oraz przepisy polskiego prawa. Podano ograniczenia podstawowe i poziomy dopuszczalne, a także techniki pomiarowe i symulacyjne wykorzystywane w dozymetrii.

  • Ogrody terapeutyczne w placówkach służby zdrowia.
    • Monika Trojanowska
    2013 Zeszyty Naukowe Politechniki Gdańskiej. Inżynieria Lądowa i Wodna

    Tematyką proponowanej pracy jest analiza i ocena światowej wiedzy teoretycznej i doświadczeń związanych z projektowaniem ogrodów terapeutycznych w placówkach służby zdrowia. W pierwszej części podjęto próbę wyjaśnienia pojęcia ogrodu terapeutycznego. Opisano przegląd literatury odnośnie badań nad terapeutyczną rolą krajobrazu. Wyszczególniono ogrody terapeutyczne specjalistyczne wykorzystywane w terapiach konkretnych, sprecyzowanych schorzeń. Opisano przykłady przyszpitalnych ogrodów terapeutycznych we Francji i Szwecji. Na końcu podjęto próbę oceny ogrodu terapeutycznego powstałego w Polsce przy Domu Pomocy Społecznej im. Jana Pawła II w Nasielsku, woj. Mazowieckie, oraz zaprezentowano wnioski.

  • Określenie przyczyn uszkodzenia śrub w połączeniach nakładek wyciszających na mostowych urządzeniach dylatacyjnych
    • Dariusz Kowalski
    • Elżbieta Urbańska-Galewska
    2013

    Zakres ekspertyzy technicznej dotyczy elementów uzbrojenia obiektów mostowych w elementy nakładek wyciszających montowanych na dylatacjach mostowych. Celem ekspertyzy jest ocena przyczyn odpadania wspomnianych nakładek i pękania śrub je mocujących części nakładek wyciszających montowanych na dylatacyjnych urządzeniach mostowych zastosowanych w ciągu drogi ekspresowej.

  • Określenie zawartości lotnych kwasów tłuszczowych (LKT) w odciekach pochodzących z mikrobiologicznej degradacji monosacharydów
    • Milena Alicja Jabłońska
    • Maria Rybarczyk
    • Marek Lieder
    2013

    Określenie zawartości lotnych kwasów tłuszczowych (LKT) w odciekach pochodzących z mikrobiologicznej degradacji monosacharydów. Milena Jabłońska, Maria Rybarczyk, Marta Wisielewska, Marek Lieder Politechnika Gdańska, Wydział Chemiczny, Katedra Technologii Chemicznej Zawartość lotnych kwasów tłuszczowych (LKT) w metabolitach pochodzących z mikrobiologicznego ogniwa paliwowego (MFC – Microbial Fuel Cell) świadczy o rozkładzie odpadów monosacharydowych. jakie poddawane są biodegradacji. W niniejszej prezentacji użyto wyników z analiz degradacji ksylozy. Rozkład monosacharydu opiera się na degradacji biotycznej anaerobowej. Spodziewanymi szczepami gatunków degradujących monocukier są: E. Coli, G. Sulfurreducens oraz Sphaerochaeta, które to prowadzą do powstawania LKT [1,4]. Pierwszy etap rozkładu odpadów nosi nazwę fazy acidogennej (kwaśnej), gdzie powstają duże ilości LKT a co za tym skutkuje – spadek pH. W kolejnych etapach biodegradacji odpadu odczyn ulega stabilizacji na poziomie ok. pH=5,6 co dowodzi, iż powstanie kwasów karboksylowych jest równoważone przez ich rozkład. LKT sprzyjają oczyszczaniu ścieków,gdyż stanowią źródło energii i węgla dla mikroorganizmów [2]. Wykonane analizy chromatograficzne wskazują na obecność takich kwasów jak: octowy, propionowy, masłowy, izo-masłowy oraz pentanowy [5]. Pobierane próbki analizowano dzięki GC-MS (Gas chromatography–mass spectrometry) [3,5]. Próbki do analiz były pobierane w trzech momentach: przed podaniem paliwa, po 1 godz. po dodaniu paliwa gdy następował wzrost napięcia ogniwa oraz po 24godz. od dodania paliwa, gdy napięcie zaczęło się obniżać. Literatura: [1] Chae K-J, Choi M-J, Lee J-W, Kim K-Y, Kim IS. Effect of different substrates on the performance, bacterial diversity and bacterial viability in microbial fuel cells. Bioresour Technol 2009;100:3518e25. [2] He Z, HuangY, ManoharAK, Mansfeld F. Effect of electrolyte pH on the rate of the anodic and cathodic reactions in an aircathodemicrobial fuel cell. Bioelectrochemistry 2008;74:78e82. [3] Kim HJ, Park HS, Hyun MS, Chang IS, Kim M, Kim BH. A mediator-less microbial fuel cell using a metal reducing bacterium, Shewanella putrefaciens. Enzym Microb Tech 2002;30:145e51. [4] Logan BE, Regan JM. Electricity-producing bacterial communities in microbial fuel cells. Trends Microbiol 2006;14:512e8. [5] Liu H, Cheng S, Logan BE. Production of electricity from acetate or butyrate using a single-chamber microbial fuel cell. Environ Sci Technol 2005;39:658e62.

  • Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
    • Anna Lis
    • Adrian Lis
    2013

    The acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining private property of an agent) and emphasises the necessity of strategic planning of their conversion (which, in turn, enables to estimate the dynamics of the agent’s development). These two dimensions allow agents to make relatively accurate decisions within the basic field of action, increasing the competitive potential of such agents.

  • On a matching distance between rooted phylogenetic trees
    • Damian Bogdanowicz
    • Krzysztof Giaro
    2013 Full text International Journal of Applied Mathematics and Computer Science

    The Robinson–Foulds (RF) distance is the most popular method of evaluating the dissimilarity between phylogenetic trees. In this paper, we define and explore in detail properties of the Matching Cluster (MC) distance, which can be regarded as a refinement of the RF metric for rooted trees. Similarly to RF, MC operates on clusters of compared trees, but the distance evaluation is more complex. Using the graph theoretic approach based on a minimum-weight perfect matching in bipartite graphs, the values of similarity between clusters are transformed to the final MC-score of the dissimilarity of trees. The analyzed properties give insight into the structure of the metric space generated by MC, its relations with the Matching Split (MS) distance of unrooted trees and asymptotic behavior of the expected distance between binary n-leaf trees selected uniformly in both MC and MS (Θ(n^1.5)).

  • ON EGNOS MONITORING IN LOCAL CONDITIONS
    • Andrzej Felski
    • Aleksander Nowak
    2013 Full text Artificial Satellites, Journal of Planetary Geodesy

    Any SBAS system should deliver to the user corrections to pseudoranges as well as information about the system integrity. In theory, as soon as the system is permanently monitored by RIMS stations, it is impossible to deliver the fault information to the user. However many observations shows that accuracy of EGNOS service in the same time are different in different places, which shows the influence of local conditions on them. In addition evidences on possibilities in jamming or spoofing of GPS signals should be seriously taken into account. According to many sources of information, among them observations of authors, present accuracy of EGNOS service has better than declared. In fact EGNOS accuracy is about 1,5m (95%), but availability of the service happens still controversial and it has random character. According to reports essential differences as well as lack of correlation of this parameter in the different point of observations has been observed. So in author’s opinion Local Monitoring of EGNOS service can contribute to better confidence of local users, especially in critical operations, like for example berthing of big ships or in landing operations with EGNOS procedures. An example of such system which works in real time has been elaborated in Polish Naval Academy and will be presented.

  • On Explaining Intuitiveness of Software Engineering Techniques with User eXperience Concepts
    • Anna Bobkowska
    2013

    W referacie zawarto próbę wyjaśnienia intuicyjności technik inżynierii oprogramowania za pomocą pojęć zaczerpniętych z obszaru doświadczenia użytkownika. Analizy dotyczą zarówno intuicyjności przy pierwszym zetknięciu się użytkownika z daną techniką, jak i dynamiki transformacji epizodycznych doświadczeń na doświadczenie skumulowane i powiązane z nim postrzeganie intuicyjności. Przedyskutowano potencjalne zastosowania modelu i zaprezentowano przykładowe wyjaśnienia zjawisk, które wynikają z modelu.

  • On Invariants of Fluid Mechanics Tensors
    • Krzysztof Tesch
    2013 Full text TASK Quarterly

    This paper presents physical interpretations of the first and second invariants of tensors of fluid mechanics. Some examples of elementary applications and meanings are also given.

  • On minimum cost edge searching
    • Dariusz Dereniowski
    • Danny Dyer
    2013 Full text THEORETICAL COMPUTER SCIENCE

    We consider the problem of finding edge search strategies of minimum cost. The cost of a search strategy is the sum of searchers used in the clearing steps of the search. One of the natural questions is whether it is possible to find a search strategy that minimizes both the cost and the number of searchers used to clear a given graph G. We call such a strategy ideal. We prove, by an example, that ideal search strategies do not exist in general. On the other hand, we provide a formula for the cost of clearing complete graphs. From our construction it follows that an ideal search strategy of a complete graph does exist and can be calculated efficiently. For general graphs G we give a polynomial-time O(log n)-approximation algorithm for finding minimum cost search strategies. We also prove that recontamination does not help to obtain minimum cost edge search strategies.

  • On mixing in the class of quadratic stochastic operators
    • Wojciech Bartoszek
    • Małgorzata Pułka
    2013 NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS

    We study different types of limit behavior of quadratic stochastic operators acting on ℓ^1 (or ℓ^1_d) spaces in both strong and uniform topologies. The main motif of the paper is to express the uniform and strong asymptotic stability of the quadratic stochastic operator in terms of convergence of the associated (linear) nonhomogeneous Markov chain. We also examine which type of uniform convergence of iterates of the quadratic stochastic operator is prevalent.

  • On Sample Rate Conversion Based on Variable Fractional Delay Filters
    • Marek Blok
    2013 International Journal of Computer Science and Application

    The sample rate conversion algorithm based on variable fractional delay filters is often used if the resampling ratio cannot be expressed as the ratio of small integer numbers or if it is not constant. The main advantage of such solution is that it allows for arbitrary resampling ratios which can even be changed during the resampling process. In this paper a discussion on influence of different approaches to fractional filter design on performance of sample rate conversion algorithm implemented using variable fractional delay filters is presented. Since the performance of such resampling algorithm depends solely on the method used to design fractional delay filters, we present its properties in relation to the presented classification of fractional delay filter design methods. The proposed general categories of fractional filter design are: optimal design, offset window method and polyphase decomposition.

  • On Software Unit Testing For Security and Performance Gain At Unit Level
    • Henryk Krawczyk
    • Marcin Barylski
    • Adam Barylski
    2013

    Performance and security are software (SW) application attributes situated on the opposite corners of system design. In the most drastic example the most secure component is the one totally isolated from the outside world, with communication performance reduced to zero level (e.g. disconnected physically from the network, placed inside a Faraday cage to eliminate possible wireless accessibility). On the other hand the most performance-optimized system is the one with all security rules taken off. Obviously such extreme implementations cannot be accepted, thus a reasonable trade-off between security and performance is desired, starting from the appropriate design, resulting in the adequate implementation, confirmed by security and performance testing in production environment. Unit Testing (UT) is a well-know method of examining the smallest portion of SW application source code – units: methods, classes, interfaces in order to verify whether they behave as designed. Ideally, each UT test case is separated from others, taking advantage of stubs and mocks to provide full isolation from external test factors. This paper is an extension to research about joint security testing and performance testing for improving quality of distributed applications working in public-private network environments, addressing SW quality assessment at different, unit test level.

  • On Some Aspects of Fish Target Strength Estimation in Shallow Waters
    • Marek Moszyński
    2013

    The theory of acoustic surveys for determining fish abundance are well established in fishery acoustics. The origins of the estimation are related to overcoming the problem of unknown position of target in the beam using statistical inversion. Although recently researchers use more sophisticated echosounders that provides more informative data allowing for direct solution it is known that the results are biased due to not ideally conical shape of beam pattern function. Performing acoustic surveys in shallow waters may present many challenges. In the paper the problems of statistical inversion of single-beam data are considered mainly by discussing two specific aspects, i.e. the problem of collecting signals from large targets in the beam side-lobes, and moreover the problem of collecting echoes from the same target several times including main-lobe and side-lobe observations. As a result of theoretical considerations new formulae of beam pattern PDF (the kernel of inversion algorithm) recommended for shallow water surveys is proposed.

  • On the fast BSS transition algorithms in the IEEE 802.11r local area wireless networks
    • Przemysław Machań
    • Józef Woźniak
    2013 Full text TELECOMMUNICATION SYSTEMS

    Handover performance is critical to support multimedia services that are becoming increasingly available over the wireless devices. The high transition delay can be unaccepted for such services or can be a source of disruption on the session. On the other side, IEEE 802.11 standard is being extended with new functionalities. Security and QoS features, included in recent IEEE 802.11-2007 standard, add management frames that are exchanged during the transition process. In consequence the handover delay is increased. IEEE 802.11r-2008 amendment introduces Fast BSS Transition (FT) that simplifies the handover process. The authors propose the new handover algorithms based on FT protocol and compare them with existing solution. Additionally, simulation experiments are conducted to answer the question if multimedia services can be properly supported in IEEE 802.11r networks. The authors prove that handover delay can be reduced to 13 ms in the average case.

  • On the necessity of experimental verification of numerical results in biomedical applications
    • Grzegorz Rotta
    • Tomasz Seramak
    2013

    Porous structures made of metal or biopolymers with a structure similar in shape and mechanical properties to human bone can be easily produced by stereolitography techniques, e.g. selective laser melting (SLM). Numerical techniques, like finite element method (FEM) have great potential in testing new, even the most sophisticated designs, according to their mechanical properties, i.e. strength or stiffness. However, due to different types of elements and varying mesh density of the model, numerical results can vary over a wide range. Experimental verification would be helpful for adjusting optimal mesh density and selecting proper element type, in order to obtain reliable results connected with reasonable solution time. This paper shows variability of results regarding to mesh density, and element types.

  • On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings
    • Michał Wasilczuk
    • Grzegorz Rotta
    2013 Full text TRIBOLOGY LETTERS

    Journal Menu About this Journal Abstracting and Indexing Aims and Scope Article Processing Charges Articles in Press Author Guidelines Bibliographic Information Citations to this Journal Contact Information Editorial Board Editorial Workflow Free eTOC Alerts Publication Ethics Submit a Manuscript Table of Contents Abstract Full-Text PDF Full-Text HTML Full-Text ePUB Linked References How to Cite this Article ISRN Tribology Volume 2013 (2013), Article ID 732790, 9 pages http://dx.doi.org/10.5402/2013/732790 Research Article On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings Michal Wasilczuk and Grzegorz Rotta Faculty of Mechanical Engineering, Gdansk University of Technology, Narutowicza 11/12, 80-233 Gdansk, Poland Received 6 November 2012; Accepted 24 November 2012 Academic Editors: N. Gerolymos and Z. Wen Copyright © 2013 Michal Wasilczuk and Grzegorz Rotta. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Different systems of direct oil supply have been developed in order to facilitate efficient introduction of fresh lubricant to the oil gap and reduction of churning power loss in tilting pad thrust bearings. Up to now there is no documented application of the supply groove in large thrust bearings used in water power plants. The results of modeling lubricant flow in the lubricating groove of a thrust bearing pad will be presented in the paper. CFD software was used to carry out fluid film calculations. Such analysis makes it possible to modify groove geometry and other parameters and to study their influence on bearing performance. According to the results a remarkable decrease in total power loss due to avoiding churning losses can be observed in the bearing.

  • On the ratio between 2-domination and total outer-independent domination numbers of trees
    • Marcin Krzywkowski
    2013 CHINESE ANNALS OF MATHEMATICS SERIES B

    A 2-dominating set of a graph G is a set D of vertices of G such that every vertex of V(G)D has a at least two neighbors in D. A total outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of G has a neighbor in D, and the set V(G)D is independent. The 2-domination (total outer-independent domination, respectively) number of a graph G is the minimum cardinality of a 2-dominating (total outer-independent dominating, respectively) set of G. We investigate the ratio between 2-domination and total outer-independent domination numbers of trees.

  • On the Structure and Volumetric Properties of Solvated Lanthanoid(III) Ions in Amide Solutions
    • Anna Fuchs
    • Daniel Lundberg
    • Dorota Warmińska
    • Ingmar Persson
    2013 Full text JOURNAL OF PHYSICAL CHEMISTRY B

    The coordination chemistry and the volumetric properties of three representative lanthanoid(III) ions lanthanum-(III), gadolinium(III), and lutetium(III) have been studied in three amide solvents with gradually increasing spatial demand upon coordination: N,N-dimethylformamide (dmf) <N,N-dimethylacet- amide (dma) <N,N-dimethylpropionamide (dmp). Large angle X-ray scattering (LAXS) and EXAFS have been used to determine the structure of the solvated lanthanoid(III) ions in solution, further supplemented with a crystallographic study on octakis(N,N-dimethylacetamide)lanthanum(III) triflate, [La(dma)8](CF3SO3)3. The selection of ions and solvents allows an estimate of the steric congestion effects on the resulting coordination number, CN,ranging from nine for lanthanum(III) ions in dmf to seven for the smaller lutetium(III) ion in space-demanding dma. The standard partial molar volumes of the solvated lanthanoid(III) ions in water and dmf are reflected in the CNs, as these solvent molecules are small enough to not interfere with each other upon coordination. However, the larger and more space-demanding dma displays a different pattern with an almost constant standardpartial molar volume and a decreasing CN, counterbalancing the difference in ionic radius of the lanthanoid(III) ion.

  • On the Transcendental Philosophy in the Light of the Kantian Aggregate - System Opposition
    • Przemysław Parszutowicz
    2013 Full text Archiwum Historii Filozofii i Myśli Społecznej

    Th e article represents an attempt to determine the essence of critical philosophy in the light of Kantian distinction between aggregate and system. In order to achieve this, the article harks back to Kant’s work and to accomplishments of Marburg School of neo-Kantianism and particularly to Ernst Cassirer’s philosophy. Discrimination between aggregate and system as two possible types of knowledge representation rests on the precedent discrimination between substance and function and constitutes the main motive that determines the basic core of philosophical transcendental method in its opposition to the “dogmatic” method.