2014 - Repozytorium publikacji - Politechnika Gdańska

Pokaż publikacje z roku

Publikacje z roku 2014

Pokaż wszystkie

Aktywności stymulujące refleksję w nauczaniu języka pisanego w wirtualnej klasie
- Iwona Mokwa-Tarnowska
2014 Pełny tekst NEOFILOLOG
The paper aims to show how to engage students attending an online language course in various activities which by stimulating reflection enhance the learning process and result in better learning outcomes. By blending cognitivist, constructivist, constructionist and behavioural ideas, course developers and tutors can produce materials and use methods which satisfy the varied needs of adults who want to improve their writing skills. Such a blend leads to a unique design, which can be achieved by tools available in a virtual learning environment. The variety of opportunities that a VLE creates allow more satisfying and challenging course materials to be built, which also help learners to develop reflective, analytical, critical and problem-solving skills. Course participants will be more adequately prepared for writing genuine texts in the future through use of a variety of activities such as: working with authentic resources integrated with different tasks and assignments to stimulate reflection; studying under the supervision and guidance of the tutor; participating in collaborative and cooperative projects to promote learner autonomy; developing new knowledge through meaning-making discussions; doing peer review as well as summative, formative assessment, and self-assessment. Experience of these ways of working will help the participants to eventually become self-regulated, lifelong learners.
Aktywny system RFID do lokalizacji i identyfikacji obiektów w wielomodalnej infrastrukturze bezpieczeństwa
- Janusz Cichowski
- Andrzej Czyżewski
2014 Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne
Przedstawiono prace koncepcyjne, badawcze oraz implementacyjne skoncentrowane na praktycznej realizacji systemu detekcji obiektów z wykorzystaniem kamer wizyjnych i identyfikacji radiowej. Zaproponowano rozbudowę wielomodalnego teleinformatycznego systemu bezpieczeństwa o warstwę identyfikacji radiowej obiektów. Omówiono założenia zaprojektowanego systemu oraz opracowaną warstwę sprzętową. Zaproponowano i przedyskutowano praktyczne zastosowania opisanego systemu.
Akustyka podwodna historia i współczesność
- Roman Salamon
- Eugeniusz Kozaczka
- Grażyna Grelowska
2014
Jubileusz pięćdziesięciolecia Komitetu Akustyki Polskiej Akademii Nauk, przypomnienie drogi która przeszła polska akustyka w tym długim, półwiecznym okresie. Na tym tle, w sposób bardziej widoczny jawi się jej stan aktualny, obecne osiągnięcia, a w tym temat akustyki podwodnej. Nazwa „hydroakustyka” lub „akustyka podwodna” określa się obszar nauki i techniki zajmującą się pozyskiwaniem i przekazywaniem informacji w środowisku wodnym przy wykorzystaniu fal akustycznych. W definicji tej mieszczą się dwa podstawowe nurty, a mianowicie twórcza działalność o charakterze inżynierskim, której celem jest budowanie narzędzi do pozyskiwania (hydrolokacja) i przekazywania (hydrokomunikacja) informacji pod woda oraz nurt badawczy, którego celem jest opis, pozyskiwanie i wykorzystywanie informacji o szeroko rozumianym środowisku wodnym.
Algorithm for Automatic Wear Estimation of Railway Contact Strips Based on 3D Scanning Results
- Sławomir Judek
- Leszek Jarzębowicz
2014
Electric rail vehicles use current collection system which consists of overhead contact line and a current collector (pantograph) mounted on the roof of a vehicle. A pantograph is equipped with contact strips, which slide along the contact wire, ensuring steady electric contact. Contact strips are made of carbon layer, fixed to an aluminum carrier. The carbon layer wears down due to friction. Using overly worn contact strips increases the rate of contact wire wear and, significantly, the risk of contact line damage. Therefore, thickness of carbon strips has to be inspected periodically. In previous work a 3D-scanning system has been proposed for recording data of contact strips when vehicles pass an inspection point on a railway line. However, the system has to be complemented with data analysis algorithm to estimate the thickness of the carbon layer. Data processing has to be performed quickly and automatically to prevent faulty pantographs from being used. The main difficulty of wear analysis is caused by diverse altitude and tilt of scanned contact strips. To determine the smallest thickness of carbon layer, the carbon surface data have to be normalized with respect to an aluminum carrier. The location and shape of the aluminum carrier can be extracted from the registered data. Due to the fact that the profile of the carrier is highly distorted, a robust Whittaker approximation algorithm has been proposed in order to deal with the noise and the missing data.
Algorithms for testing security in graphs
- Arkadiusz Hiler
- Robert Lewoń
- Michał Małafiejski
2014 Pełny tekst Studia i Materiały Informatyki Stosowanej
In this paper we propose new algorithmic methods giving with the high probability the correct answer to the decision problem of security in graphs. For a given graph G and a subset S of a vertex set of G we have to decide whether S is secure, i.e. every subset X of S fulfils the condition: |N[X] \cap S| >= |N[X] \ S|, where N[X] is a closed neighbourhood of X in graph G. We constructed a polynomial time property pseudotester based on the heuristic using simulated annealing and tested it on graphs with induced small subgraphs G[S] being trees or graphs with bounded degree (by 3 or 4). Our approach is a generalization of the concept of property testers known from literature, but we applied our concepts to the coNP-complete problem.
Algorytmy przetwarzania widm Ramana w procesie detekcji substancji chemicznych
- Andrzej Kwiatkowski
2014
Rozprawa przedstawia szczegółowo algorytmy, jakie są stosowane podczas przetwarzania widm Ramana, rejestrowanych przenośnym spektrometrem o skończonej rozdzielczości. Pracę podzielono na osiem rozdziałów. W pierwszym określono cel i tezy pracy. Rozdział drugi opisuje podstawowe pojęcia dotyczące zjawiska Ramana oraz zasady budowy urządzeń do pomiarów widm Ramana. W rozdziale trzecim scharakteryzowano błędy występujące podczas pomiarów widm Ramana i oceniono wpływ opakowania, w którym znajduje się badana próbka na przebieg rejestrowanego widma. Rozdział kończy analiza znaczenia czasu ekspozycji matrycy CCD na jakość rejestrowanych widm. Czwarty rozdział prezentuje metody wstępnego przetwarzania widm Ramana oraz metody określania parametrów najsilniejszych linii spektralnych. W rozdziale piątym zaprezentowano algorytmy detekcji substancji chemicznych na podstawie metod korelacyjnych, metody maszyny wektorów nośnych oraz na podstawie porównywania parametrów linii widmowych. W rozdziale szóstym przedstawiono wyniki pomiarów widm Ramana dla kilku wybranych substancji, w tym pomiarów i metod detekcji śladowych ilości produktów rozpadu Bitrexu, stosowanego do zanieczyszczania alkoholu etylowego, przy zastosowaniu techniki powierzchniowego wzmocnienia sygnału Ramana. Rozdział siódmy zawiera ocenę selektywności detekcji wybranych substancji chemicznych na podstawie mierzonych widm Raman. Oceniono odporność proponowanych algorytmów detekcji ze względu na składową losową w rejestrowanych widmach oraz na błąd wyznaczenia przesunięć Ramana dla identyfikowanych linii widmowych. Rozdział ósmy zawiera wnioski końcowe.
Al(III) and Cu(II) simultaneous foam separation: Physicochemical problems
- Bożenna Kawalec-Pietrenko
- Piotr Rybarczyk
2014 Pełny tekst CHEMICAL PAPERS
Simultaneous removal of Al(III) and Cu(II) from dilute aqueous solutions by ion and precipitate flotation methods is investigated. Influence of the pH of the initial solution, the surface active collector concentration and the gas flow rate on the final removal ratio and the course of ion and precipitate flotations is presented. Results show that simultaneous flotations of Al(OH)3 and Cu(OH)2 insoluble species occur allowing to achieve their almost complete removal in the pH range between 7 and 9. An increase of the surface active agent concentration causes a decrease of the final removal ratio as well as of the flotation rate constant. An increase of the gas flow rate results in an increase of ion and precipitate flotation rates.
Alternative convolution approach to friction in unsteady pipe flow
- Romuald Szymkiewicz
- Marek Mitosek
2014 JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
In the paper some aspects of the unsteady friction in pipe flow expressed by the convolution are analyzed. This additional term introduced into the motion equation involves the accelerations of fluid occurring in the past and a weighting function. The essence of such approach is to assume the appropriate form of weighting function. However, until now no fully reliable formula for this function has been found. To avoid some inconveniences typical for the commonly used weighting functions, an alternative form of the convolution is proposed. Instead of a weighting function an impulse response function in a general form is introduced. This function, defined in the real time domain, having clear physical interpretation and some useful properties is not related to the usually assumed viscosity distribution over the pipe’s cross section. The proposed approach involves two parameters. The convergence of the impulse response function, characterized by the flow memory, is determined by a parameter which can be related to the pressure wave frequency. The second parameter determines the magnitude of the unsteady friction force. The proposed alternative convolution approach was tested basing on the laboratory measurements for a water hammer event initiated by turbulent flow in pipes made of steel. Although the alternative convolution approach causes a very good damping of the pressure wave amplitude, it appears to be unable to ensure appropriate smoothing of the pressure heads. This is because it acts in the dynamic equation as a source/sink term. To ensure the required smoothing of the pressure wave the diffusive term was included into the dynamic equation.
An advanced Thermal-FSI approach to flow heating/cooling
- Janusz Badur
- Paweł Ziółkowski
- Witold Zakrzewski
- Daniel Sławiński
- Sebastian Kornet
- Tomasz Kowalczyk
- Jakub Hernet
- Rafał Piotrowski
- Judyta Felicjancik
- Piotr Ziółkowski
2014 Pełny tekst Journal of Physics : Conference Series
Actually, two-way thermal-energy exchange between working fluid and solid material of a casing is a leading problem for modern – semi automatic – design techniques. Many questions should be solved, especially, the turbulent mode of thermal energy transport both in fluid and solid, should be re-examined and reformulated from the primary principles. In the present paper, a group of researchers from Energy Conversion Department of IMP PAN at Gdańsk, tries to summarise a last three-years efforts towards to mathematical modelling of advanced models of thermal energy transport. This extremely difficult problem in "thermal-FSI" ("Fluid Solid Interaction") means that the both for solid and fluid mathematical model of a surface layer should be self-equilibrated and self-concise. Taking these requirements into account, an advanced Reynolds-Stanton analogy has been discussed and implemented. Some numerical examples concerning of the benchmarks experiments and industrial applications have also been developed and presented.
An algorithm for listing all minimal double dominating sets of a tree
- Marcin Krzywkowski
2014 FUNDAMENTA INFORMATICAE
We provide an algorithm for listing all minimal double dominating sets of a tree of order $n$ in time $\mathcal{O}(1.3248^n)$. This implies that every tree has at most $1.3248^n$ minimal double dominating sets. We also show that this bound is tight.
AN ALGORITHM FOR PORTAL HYPERTENSIVE GASTROPATHY RECOGNITION ON THE ENDOSCOPIC RECORDINGS
- Jan Cychnerski
- Piotr Dorożyński
- Tomasz Dziubich
2014
Symptoms recognition of portal hypertensive gastropathy (PHG) can be done by analysing endoscopic recordings, but manual analysis done by physician may take a long time. This increases probability of missing some symptoms and automated methods may be applied to prevent that. In this paper a novel hybrid algorithm for recognition of early stage of portal hypertensive gastropathy is proposed. First image preprocessing is described. Then disease symptoms characteristics are presented and hybrid algorithm scheme combining edge detection, Local Binary Patterns and local maxima clustering is shown. Finally the detailed description of these methods are provided. The pa- rameters of the algorithm are also described with ranges used in tests and their best values (obtained empirically) are presented. The proposed algorithm is tested and compared to a few other algorithms showing it’s comparable in terms of effectiveness in general case and a bit better than other ones in recognition of early stage of PHG.
An Analysis of Contextual Aspects of Conceptualization: A Case Study and Prospects
- Krzysztof Goczyła
- Aleksander Waloszek
- Wojciech Waloszek
2014
In this chapter we present a new approach to development of modularized knowledge bases. We argue that modularization should start from the very beginning of modeling, i.e. from the conceptualization stage. To make this feasible, we propose to exploit a context-oriented, semantic approach to modularization. This approach is based on the Structural Interpretation Model (SIM) presented earlier elsewhere. In the first part of thischapter we present a contextualized version of the SYNAT ontology developed using the SIM methodology. For the approach to be useful in practice, a set of tools is needed to enable a knowledge engineer to create, edit, store and perform reasoning over contextualized ontologies in a flexible and natural way. During our work on the SYNAT project, we developed such a set of tools that are based on a mathematical ground of tarset algebra (also introduced elsewhere). In the second part of this chapter we give a deeper insight into some aspects of using these tools, as well as into ideas underlying their construction. The work on contextualization of knowledge bases led us to further theoretical investigation of hierarchical structure of a knowledge base systems. Indeed, in a system of heterogeneous knowledge sources, each source (a knowledge base) can be seen in its own separate context, as being a part of a higher level contextual structure (a metastructure) with its own set of context parameters. Higher levels of the knowledge hierarchy do not substantially differ from basic SIM structure, so that all context-aware services, including reasoning, can be performed. The theoretical background of this conception is presented in the third part of this chapter.
An Analysis of Probe-Fed Rectangular Patch Antennas With Multilayer and Multipatch Configurations on Cylindrical Surfaces
- Rafał Lech
- Wojciech Marynowski
- Adam Kusiek
- Jerzy Mazur
2014 Pełny tekst IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
A multi-patch configuration of probe-fed rectangular microstrip antennas mounted on a cylindrical body, with electrically small radius, with an arbitrary number of substrate and superstrate layers is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. A unified procedure for creating proper matrices for the investigated geometry of the structure is outlined here. Numerical results for the input impedances and radiation patterns are calculated and verified by comparing them with results from the literature and our own measurements of manufactured prototypes.
An application of blended and collaborative learning in spatial planning course
- Dominika Wróblewska
- Romanika Okraszewska
- Artur Janowski
2014
Spatial Planning is a master course for graduate students of Environmental Engineering. The course is based on assumptions that students’ future work will be connected with spatial planning, and spatial issues will have an influence on their everyday lives. To familiarize students with environmental issues in planning, the teams of students get an assignment to design an urban space, waterfront along a stream. The whole project consists of four subprojects logically linked with each other. To prepare students for public engagement in planning, collaborative learning elements have been implemented. A variety of blended learning and collaborative learning activities have been designed. Traditional face-to-face classes involve lectures, staff consultation hours, project work, presentations and open discussions for all students enrolled for the course. E-learning components have been developed in Moodle, and they include activities such as: building an open glossary, voting on presentations and others. Moodle platform is also used as a database of students’ subprojects and presentations in read-only mode. Moreover, it allows assessing the results of student work according to defined criteria, creating databases of links to data sources, encouraging student public participation by informing them about open meetings, conferences and seminars. The students also use other open source systems such as GIS (Geographical Information Systems), WMS (Web Map Systems), institutions websites and CAD software for data visualization. The main problems that appeared while running the course were mostly connected to collaborative team work and failure of additional activities, which were only used by a few students (the quiz was an exception). The course was evaluated anonymously by students, who gave several pieces of advice on course improvement, mainly on collaborative work. This article presents the structure of the course and correlation between collaborative learning and blended learning and its effects. The problems that appeared during the first year of the course are discussed below. The conclusions drawn from the analysis of the course will be used as guidelines for future improvements of the Spatial Planning teaching process.
An Application Supporting Gastroesophageal Multichannel Intraluminal Impedance-pH Analysis
- Piotr Tojza
- Dawid Gradolewski
- Grzegorz Redlarski
2014
Due to a significant rise in the number of patients diagnosed with diseases of the upper gastrointestinal tract and the high cost of treatment, there is a need to further research on one of the most popular diagnostic tests used in this case – esophageal Multichannel Intraluminal Impedance and pH measurement. This may lead to finding new diagnostically relevant information, used to quicken and improve the diagnostic procedure. The paper presents an algorithm used in a new computer application dedicated for researchers and physicians interested in research connected with Gastroesophageal impedance and pH data analysis. A possibility to modify a wide range of the algorithms parameters as well as rich set of the programs functions allows researchers to search for new criteria to assess the pH and impedance data when diagnosing diseases of the upper gastrointestinal tract. This, in turn, may lead to improving the time and accuracy of the MII-pH analysis which will substantially affect the patient’s diagnosis time and treatment. Moreover, the diagnosing physician will be able to asses more tests, which is important, due to a significant rise in the number of patients seeking attention when speaking about the diseases of the upper gastrointestinal tract.
An Approach to Bass Enhancement in Portable Computers Employing Smart Virtual Bass Synthesis Algorithms
- Piotr Hoffmann
- Tomasz Sanner
- Bożena Kostek
2014
The aim of this paper is to present a novel approach to the Virtual Bass Synthesis (VBS) algorithms applied to portable computers. The developed algorithms are related to intelligent, rule-based setting of synthesis parameters according to music genre of an audio excerpt and to the type of a portable device in use. To find optimum synthesis parameters of the VBS algorithms, subjective listening tests based on a parametric procedure were performed. The classification of music genres is automatically executed employing MPEG 7 parameters and the Principal Component Analysis method applied to reduce information redundancy. The VBS algorithm performs the synthesis based on a nonlinear device (NLD) or phase vocoder (PV) depending on the content of an audio file excerpt. A soft computing (fuzzy logic) algorithm is employed to set optimum synthesis parameters depending on a given song.
An asymmetrical λ-foot of condensing steam flow in the IMP PAN nozzle
- Sebastian Kornet
- Janusz Badur
2014 Pełny tekst Journal of Physics : Conference Series
In the present paper we have focused on the precise prediction of the spontaneous condensation phenomena in wet steam flow. Novelty of our approach lies on modelling both the moment of initiation of a phase transition, as well as the moment of its reverse progress - called here re-vaporization of the condensate phase. The practical issue is to elaborate of a model of spontaneous condensation/vaporization of water steam flow under low-pressure conditions by using methodology of non-equilibrium thermodynamics [2]. The basic tests including comparison with an experimental data have been performed using the IMP PAN nozzle with the de Laval geometry [1]. Having observed the finishing of a foggy flow within the shock wave, according to Puzyrewski’s postulate [1], we would like to analyse the topography of the shock wave pattern in the IMP PAN symmetric nozzle. This phenomenon, independently from a type of compressible fluid, has been observed to be the result of interaction between a normal shock wave and the boundary layer – it has been known as a lambda-foot structure [3]. The asymmetry of the shock structure is measured by optical system and visible since the foggy flow can be easily observed. Our paper is a trial towards to an explanation of this problem.
An attempt to create a digital reconstruction of the Copper Ship = Próba cyfrowej rekonstrukcji kadłuba wraku Miedziowca
- Cezary Żrodowski
2014
This study presents an attempt to create a digital reconstruction of the W-5 shipwreck (the Copper Ship) based on data acquired by 3D scanning of structural components held at the National Maritime Museum in Gdańsk and on a physical reconstruction model of the ship’s hull. A digital reconstruction would facilitate analysis of various possible options for the structural design of the hull, and would enable the preparation of a model for visualisation and simulation purposes and for a physical reconstruction in the form of a 3D printout. As part of this project an attempt was made to devise and test a reconstruction methodology for salvaged shipwrecks, which often pose particular diffi culties because of: a) their great complexity, arising from their significant number of components, complicated shape, deformation in relation to their original form, and from their being disjointed and incomplete; b) the large size of some components, which often, in combination with diffi cult access, leads to problems in obtaining a complete digital image of such components; c) incomplete documentation – the wreck has been excavated, but often only scant records survive of the locations in which individual components were found on the seabed, or of the manner in which they were connected before being dismantled for conservation. In consequence, we are faced with an unusual task that entails fi tting various parts of a wreck together, primarily based on their shape – which is usually distorted. A hybrid approach was chosen which involved using scanned data combined with manual modelling (carried out using engineering support tools) based on accepted principles and archaeological knowledge on the subject of historical sailing vessels.
An Attempt to Develop a Model Selection Algorithm of Computer Simulation during the Design Process of Mechanical Response of Any Mechanical Body
- Paweł Wawrzyniak
- Waldemar Karaszewski
2014 Journal of Applied Computer Science
In the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This article is an attempt to develop a general algorithm for the very difficult stage in the design of computer simulations of technological processes, which is the choice of the appropriate subject material for the constitutive model of the technological process. In other words, the article addresses only the issue of constitutive strain-stress relations. In the literature, there is a lack of algorithms for the systematic mathematical selection of model materials for the design phase of computer simulations with regard to mechanical bodies. This paper is an attempt to develop, without program implementation, such a specific algorithm for the model material selection in the design phase of computer simulation. Development of an algorithm for the selection of suitable model material model under computer simulation provides opportunities and most importantly, it reduces the required level of education of the people creating the simulation of the technological processes; thus, the group of consumers for whom the numerical computations may be relevant, is increased.
An Efficient Framework For Fast Computer Aided Design of Microwave Circuits Based on the Higher-Order 3D Finite-Element Method
- Adam Lamęcki
- Łukasz Balewski
- Michał Mrozowski
2014 Pełny tekst RADIOENGINEERING
In this paper, an efficient computational framework for the full-wave design by optimization of complex microwave passive devices, such as antennas, filters, and multiplexers, is described. The framework consists of a computational engine, a 3D object modeler, and a graphical user interface. The computational engine, which is based on a finite element method with curvilinear higher-order tetrahedral elements, is coupled with built-in or external gradient-based optimization procedures. For speed, a model order reduction technique is used and the gradient computation is achieved by perturbation with geometry deformation, processed on the level of the individual mesh nodes. To maximize performance, the framework is targeted to multicore CPU architectures and its extended version can also use multiple GPUs. To illustrate the accuracy and high efficiency of the framework, we provide examples of simulations of a dielectric resonator antenna and full-wave design by optimization of two diplexers involving tens of unknowns, and show that the design can be completed within the duration of a few simulations using industry-standard FEM solvers. The accuracy of the design is confirmed by measurements.