2017 - Repozytorium publikacji - Politechnika Gdańska

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Odory z sieci
- Ziemowit Suligowski
2017 Magazyn Instalatora
Ogólne problemy powstawania odorów. Konsekwencje nieracjonalnego planowania sieci. Przeciwdziałanie. Ochrona ludności.
Odszedł wspaniały człowiek i wielki uczony
- Jerzy Konorski
- Józef Woźniak
2017 Pismo PG
12 października 2017 roku dotarła do nas smutna wiadomość o śmierci prof. Jerzego Seidlera . Uważany za jednego z pionierów współczesnej elektroniki, telekomunikacji i informatyki w Polsce, członek Polskiej Akademii Nauk oraz opiekun naukowy pokoleń polskich i zagranicznych badaczy, zmarł w wieku 90 lat w Salzburgu w Austrii, po owocnym i spełnionym życiu.
OGRANICZANIE NATĘŻENIA POLA ELEKTRYCZNEGO W OTOCZENIU LINII 110 kV
- Marek Olesz
2017 Pełny tekst Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
W referacie omówiono warunki techniczne podane w normach konieczne do spełnienia przy lokalizacji obiektów budowlanych zlokalizowanych w pobliżu linii napowietrznej 110 kV. Analizowano także metody ograniczania natężenia pola elektrycznego na powierzchni ziemi za pomocą dodatkowych, uziemionych elementów konstrukcyjnych oraz zmiany konfiguracji przewodów w liniach dwutorowych.
OKREŚLENIE STOPNIA DOSTĘPNOŚCI PRZESTRZENI PUBLICZNYCH NA KAMPUSIE POLITECHNIKI GDAŃSKIEJ W MYŚL TEORII PROJEKTOWANIA UNIWERSALNEGO Z UŻYCIEM METODOLOGII SPACE SYNTAX
- Ewa Marczewska
2017
W pracy podjęto próbę oceny efektywności dostępności przestrzeni publicznych na Kampusie Politechniki Gdańskiej oraz zbadania zagadnienia zgodność tych przestrzeni z założeniami projektowania uniwersalnego. Celem pracy jest zbadanie relacji między poszczególnymi obiektami dydaktycznymi, zidentyfikowanie głównych korytarzy dostępu oraz wykazanie czy przestrzeń publiczna Kampusu PG jest przestrzenią dostępną (spatial accesibillity) zgodnie z teorią projektowania uniwersalnego. By określić tą dostępność użyto metody space syntax z wykorzystaniem narzędzia DepthMap do analizy przestrzeni pod kątem dostępności wizualnej jak i fizycznej. Jest to dopełnienie badań z 2014 roku nad dostępnością samych budynków, które były oceniane metodą jakościową. Obecne badania mają służyć wypracowaniu metody parametrycznej oceny dostępności. W przestrzeniach publicznych na Kampusach edukacyjnych powinien panować utylitaryzm przestrzenny, by spełnić demokratyczne postulaty do równego dostępu do wiedzy. Jest to zgodne z wytycznymi Konwencji ONZ o prawach osób niepełnosprawnych, w szczególności art. 9 (Dostępność) i art. 24 (Edukacja). Wszelkie obecne określone bariery fizyczne oraz mentalne, prowadzić powinny do zwiększonej świadomości u projektantów przyczyn braku powszechnej dostępności zgodnej z zasadami projektowania uniwersalnego. Badania mogą posłużyć do określenia odpowiednich narzędzi oceny dostępności przestrzeni publicznych, jej sparametryzowania oraz stworzenia wytycznych, które mogą prowadzić do poprawy dostępności Kampusu PG. Obecnie nie przeprowadzono podobnej analizy przestrzeni publicznych pod kątem dostępności z punktu widzenia projektowania uniwersalnego z wykorzystaniem narzędzi Depth Map. Stwarza to nowe możliwości zastosowania kolejnego i nowego narzędzia użytecznego w projektowaniu uniwersalnym.
Określenie zasadności zastosowania instalacji ochrony katodowej nowych podziemnych zbiorników buforowych na terenie Bazy Paliw nr 21 OLPP w Dębogórzu.
- Krzysztof Żakowski
- Andrzej Dul
- Tadeusz Sonneck
2017
Wykonano badania terenowe i laboratoryjne w celu określenia potrzeby zastosowania ochrony katodowej nowych zbiorników buforowych na terenie Bazy Paliw OLPP w Dębogórzu.
On adaptive covariance and spectrum estimation of locally stationary multivariate processes
- Maciej Niedźwiecki
- Marcin Ciołek
- Yoshinobu Kajikawa
2017 Pełny tekst AUTOMATICA
When estimating the correlation/spectral structure of a locally stationary process, one has to make two important decisions. First, one should choose the so-called estimation bandwidth, inversely proportional to the effective width of the local analysis window, in the way that complies with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive estimation variance. Second, but equally important, one should choose the appropriate order of the spectral representation of the signal so as to correctly model its resonant structure – when the order is too small, the estimated spectrum may not reveal some important signal components (resonances), and when it is too high, it may indicate the presence of some nonexistent components. When the analyzed signal is not stationary, with a possibly time-varying degree of nonstationarity, both the bandwidth and order parameters should be adjusted in an adaptive fashion.Thepaperpresentsandcomparesthreeapproachesallowingforunifiedtreatmentoftheproblem of adaptive bandwidth and order selection for the purpose of identification of nonstationary vector autoregressive processes: the cross-validation approach, the full cross-validation approach, and the approach that incorporates the multivariate version of the generalized Akaike’s final prediction error criterion. It is shown that the latter solution yields the best results and, at the same time, is very attractive from the computational viewpoint.
On Algorithm Details in Multibeam Seafloor Classification
- Zbigniew Łubniewski
- Dariusz Sęk
2017 Pełny tekst HYDROACOUSTICS
Remote sensing of the seafloor constitutes an important topic in exploration, management, protection and other investigations of the marine environment. In the paper, a combined approach to seafloor characterisation is presented. It relies on calculation of several descriptors related to seabed type using three different types of multibeam sonar data obtained during seafloor sensing, viz.: 1) the grey-level sonar images (echograms) of the seabed, 2) the 3D model of the seabed surface which consists of bathymetric data, 3) the set of time domain bottom echo envelopes received in the consecutive sonar beams. The proposed methodology has been tested using field data records acquired from several bottom types in the Southern Baltic Sea. Using the examples of particular parameters, the influence on the specific manner and details regarding their calculation, i.e. the size of the applied current local window to a sonar image, on the obtained classification performance, is discussed.
On autoregressive spectrum estimation using the model averaging technique
- Michał Meller
- Maciej Niedźwiecki
- Damian Chojnacki
- Adam Lasota
2017 Pełny tekst
The problem of estimating spectral density of a nonstationary process satisfying local stationarity conditions is considered. The proposed solution is a two step procedure based on local autoregressive (AR) modeling. In the first step Bayesian-like averaging of AR models, differing in order, is performed. The main contribution of the paper is development of a new final-prediction-error-like statistic, which can be used to select optimal estimation bandwidth in the second step of the procedure. Simulation experiments demonstrate that the combined cooperative-competitive approach outperforms the previously introduced fully competitive scheme.
On Computational Aspects of Greedy Partitioning of Graphs
- Piotr Borowiecki
2017
In this paper we consider a problem of graph P-coloring consisting in partitioning the vertex set of a graph such that each of the resulting sets induces a graph in a given additive, hereditary class of graphs P. We focus on partitions generated by the greedy algorithm. In particular, we show that given a graph G and an integer k deciding if the greedy algorithm outputs a P-coloring with a least k colors is NP-complete for an infinite number of classes P. On the other hand we get a polynomial-time certifying algorithm if k is fixed and the family of minimal forbidden graphs defining the class P is finite. We also prove coNP-completeness of the problem of deciding whether for a given graph G the difference between the largest number of colors used by the greedy algorithm and the minimum number of colors required in any P-coloring of G is bounded by a given constant. A new Brooks-type bound on the largest number of colors used by the greedy P-coloring algorithm is given.
On deterministic procedures for low-cost multi-objective design optimization of miniaturized impedance matching transformers
- Sławomir Kozieł
- Adrian Bekasiewicz
2017 ENGINEERING COMPUTATIONS
Purpose This paper aims to investigate deterministic strategies for low-cost multi-objective design optimization of compact microwave structures, specifically, impedance matching transformers. The considered methods involve surrogate modeling techniques and variable-fidelity electromagnetic (EM) simulations. In contrary to majority of conventional approaches, they do not rely on population-based metaheuristics, which permit lowering the design cost and improve reliability. Design/methodology/approach There are two algorithmic frameworks presented, both fully deterministic. The first algorithm involves creating a path covering the Pareto front and arranged as a sequence of patches relocated in the course of optimization. Response correction techniques are used to find the Pareto front representation at the high-fidelity EM simulation level. The second algorithm exploits Pareto front exploration where subsequent Pareto-optimal designs are obtained by moving along the front by means of solving appropriately defined local constrained optimization problems. Numerical case studies are provided demonstrating feasibility of solving real-world problems involving expensive EM-simulation models of impedance transformer structures. Findings It is possible, by means of combining surrogate modeling techniques and constrained local optimization, to identify the set of alternative designs representing Pareto-optimal solutions, in a realistic time frame corresponding to a few dozen of high-fidelity EM simulations of the respective structures. Multi-objective optimization for the considered class of structures can be realized using deterministic approaches without defaulting to evolutionary methods. Research limitations/implications The present study can be considered a step toward further studies on expedited optimization of computationally expensive simulation models for miniaturized microwave components. Originality/value The proposed algorithmic solutions proved useful for expedited multi-objective design optimization of miniaturized microwave structures. The problem is extremely challenging when using conventional methods, in particular evolutionary algorithms. To the authors’ knowledge, this is one of the first attempts to investigate deterministic surrogate-assisted multi-objective optimization of compact components at the EM-simulation level.
On joint order and bandwidth selection for identification of nonstationary autoregressive processes
- Maciej Niedźwiecki
- Marcin Ciołek
2017 Pełny tekst
When identifying a nonstationary autoregressive process, e.g. for the purpose of signal prediction or parametric spectrum estimation, two important decisions must be taken. First, one should choose the appropriate order of the autoregressive model, i.e., the number of autoregressive coefficients that will be estimated. Second, if identification is carried out using the local estimation technique, such as the localized version of the method of least squares, one should select the most appropriate estimation bandwidth, i.e., the effective width of the local data window used for the purpose of parameter tracking. The paper presents the first unified treatment of the problem of joint order and bandwidth selection. Two solutions to this problem are examined, first based on the predictive least squares principle, and second exploiting the suitably modified Akaike’s final prediction error statistic. It is shown that the best results are obtained if the two approaches mentioned above are combined.
On my way to global science - 1933-2015 memoirs". A volume of memoirs by professor Wiesław Maria Grudzewski
- Ludmiła Zawadzka
2017 Pełny tekst International Journal of Contemporary Management
I wish to express my graditude for the oportunity to read excellent on the life and academic work of Professor Grudzewski, and outstanding scientist and unquestioned authority on economic sciences in the area of management science. Professor Grudzewski had an influence on the events presented in his memoirs through his acquaintances and associates.
On root finding algorithms for complex functions with branch cuts
- Piotr Kowalczyk
2017 Pełny tekst JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
A simple and versatile method is presented, which enhances the complex root finding process by eliminating branch cuts and branch points in the analyzed domain. For any complex function defined by a finite number of Riemann sheets, a pointwise product of all the surfaces can be obtained. Such single-valued function is free of discontinuity caused by branch cuts and branch points. The roots of the new function are the same as the roots of original multi-valued variety, while the verification of them is much easier. Such approach can significantly improve the efficiency (as well as the effectiveness) of the root finding algorithms. The validity of the presented technique is supported by the results obtained from numerical tests.
On symmetric extendibility of quantum states and its applications
- Marcin Nowakowski
2017 Pełny tekst
This dissertation is focused on analysis of the symmetric extendibility of quantum states and its applications in the quantum information theory, with special attention paid to the area of quantum entanglement distillation, quantum channels theory, quantum security, and monogamy of quantum entanglement in time. We analyze geometry of the set of symmetric extendible states, i.e. such states that possess symmetric extensions and in particular, prove that the set is closed under action of the 1-LOCC operators which is of a great importance for further applications in one-way distillability of quantum states and quantum channels theory. Basing on the Choi-Jamiolkowski isomorphism between quantum states and quantum channels, we derive a simple test for the quantum channel capacity. We discuss also monogamy of quantum entanglement and its relations with Bell theorem, and the symmetric extendibility. Further, the subject of our analysis is also the theory of quantum entanglement measures and their relation to the symmetric extendibility. A new entanglement monotone and parameter are introduced basing on this concept, which are applied as new upper bounds on distillable entanglement. We introduce the concept of reduced variants of the quantum communication rates, showing that they can efficiently estimate non-reduced quantum measures. Finally, it is derived that in the paradigm of the entangled consistent histories, introducing the concept of quantum entanglement in time, a particular history is monogamous and we can derive the Tsirelson bound on the Leggett-Garg temporal inequalities. The results presented in this PhD thesis show importance of the concept of the symmetric extendibility for further development of quantum information theory, especially in domain of one-way communication.
On the derivatives $\partial^{2}P_{\nu}(z)/\partial\nu^{2}$ and $\partial Q_{\nu}(z)/\partial\nu$ of the Legendre functions with respect to their degrees
- Radosław Szmytkowski
2017 INTEGRAL TRANSFORMS AND SPECIAL FUNCTIONS
We provide closed-form expressions for the degree-derivatives $[\partial^{2}P_{\nu}(z)/\partial\nu^{2}]_{\nu=n}$ and $[\partial Q_{\nu}(z)/\partial\nu]_{\nu=n}$, with $z\in\mathbb{C}$ and $n\in\mathbb{N}_{0}$, where $P_{\nu}(z)$ and $Q_{\nu}(z)$ are the Legendre functions of the first and the second kind, respectively. For $[\partial^{2}P_{\nu}(z)/\partial\nu^{2}]_{\nu=n}$, we find that % \begin{displaymath} \frac{\partial^{2}P_{\nu}(z)}{\partial\nu^{2}}\bigg|_{\nu=n} =-2P_{n}(z)\Li_{2}\frac{1-z}{2}+B_{n}(z)\ln\frac{z+1}{2}+C_{n}(z), \end{displaymath} % where $\Li_{2}[(1-z)/2]$ is the dilogarithm function, $P_{n}(z)$ is the Legendre polynomial, while $B_{n}(z)$ and $C_{n}(z)$ are certain polynomials in $z$ of degree $n$. For $[\partial Q_{\nu}(z)/\partial\nu]_{\nu=n}$ and $z\in\mathbb{C}\setminus[-1,1]$, we derive % \begin{eqnarray*} \frac{\partial Q_{\nu}(z)}{\partial\nu}\bigg|_{\nu=n} &=& -P_{n}(z)\Li_{2}\frac{1-z}{2} -\frac{1}{2}P_{n}(z)\ln\frac{z+1}{2}\ln\frac{z-1}{2} +\frac{1}{4}B_{n}(z)\ln\frac{z+1}{2} \nonumber \\ && -\,\frac{(-1)^{n}}{4}B_{n}(-z)\ln\frac{z-1}{2} -\frac{\pi^{2}}{6}P_{n}(z) +\frac{1}{4}C_{n}(z)-\frac{(-1)^{n}}{4}C_{n}(-z). \end{eqnarray*} % A counterpart expression for $[\partial Q_{\nu}(x)/\partial\nu]_{\nu=n}$, applicable when $x\in(-1,1)$, is also presented. Explicit representations of the polynomials $B_{n}(z)$ and $C_{n}(z)$ as linear combinations of the Legendre polynomials are given.
On the existence of homoclinic type solutions of inhomogenous Lagrangian systems
- Jakub Ciesielski
- Joanna Janczewska
- Nils Waterstraat
2017 Differential and Integral Equations
We study the existence of homoclinic type solutions for a class of inhomogenous Lagrangian systems with a potential satisfying the Ambrosetti-Rabinowitz superquadratic growth condition and a square integrable forcing term. A homoclinic type solution is obtained as a limit of periodic solutions of an approximative sequence of second order differential equations.
On the impact of Big Data and Cloud Computing on a scalable multimedia archiving system
- Sylwester Kaczmarek
- Mariusz Miszewski
- Arkadiusz Szuryn
2017 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Multimedia Archiver (MA) is a system build upon the promise and fascination of the possibilities emerging from cloud computing and big data. We aim to present and describe how the Multimedia Archiving system works for us to record, put in context and allow a swift access to large amounts of data. We introduce the architecture, identified goals and needs taken into account while designing a system processing data with Big Data characteristics coming from multiple sources. We have described the key components and features of the infrastructure and software salient features involved in our solution. In addition, we rethink the aspects of possible implementation and use, and we present the lessons learned from our experience.
On the influence of shell element properties on the response of car model in crash test
- Krzysztof Wilde
- Jacek Chróścielewski
- Wojciech Witkowski
- Stanisław Burzyński
- Dawid Bruski
2017 Pełny tekst
It goes without saying that numerical simulations play important role in the modern engineering practice. Contemporary CAD environments combined with FEM solvers, along with computer power of modern processors, give the engineer fast and efficient tool. Ultimately, however it is the user alone who is responsible for the correctness of the results. As long as the FEM calculations remain in the sphere of academic exercise, the inevitable errors/mistakes resulting from improper use of FEM systems may postpone scientific development of some ideas. This is not the case however when industry application of FEM is considered as it usually involves substantial financial or other responsibility. In particular, we may mention these applications when human safety is a key factor. In this area Ls-Dyna has its special position as a tool for simulation of car collisions. Apart from car manufacturers the code is used also by the producers of safety barriers who must adhere to the specifications of specific standards. In Europe, as of March 2017, the current state of affairs is given by EN1317-2010 standard. These include, among others, precise definitions of initial conditions for car and the placement of the car relative to the analyzed restraint system. While such precision is necessary to allow comparing different barriers it is not sufficient to cover the abundance of the real-life situations. As a part of the research project jointly funded by National Centre for Research and Development (NCBiR) and General Director for National Roads and Motorways, Poland the present authors are responsible for numerical simulations of various real-life scenarios that do not conform to those of EN1317-2010 standard. To model the barrier-car collision we use car models that are freely available, correcting them when necessary however. The major effort is put on the correct recreation of barrier geometry along with proper boundary conditions and connections between barrier parts. As far as spatial discretization is concerned the majority of car’s and barrier’s parts are modeled with shell elements. In this report we study the influence of some Ls-Dyna control cards that affect the behavior of shell elements used in FEM simulations of crash tests.
On the use of a charge balancing method for low energy measurements
- Grzegorz Lentka
- Dariusz Palmowski
- Arkadiusz Hojka
2017 Pełny tekst Przegląd Elektrotechniczny
The paper presents the method for the estimation of the energy consumption of the low-power microcontroller-based devices. Due to high dynamics of the changes of the supply current of the tested devices during the operational cycle, the consumed energy estimation is not easy. In order to avoid disadvantages of known methods, the charge balancing method was employed similarly like in some types of A/D converters.
Oocena niezawodności zaopatrzenia m. st. Warszawy w energię elektryczną
- Waldemar Kamrat
2017
Przedstawiono ocenę niezawodności zaopatrzenia w energię m. st. Warszawy.