2016 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2016

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Face detection algorithms evaluation for the bank client verification
- Maciej Szczodrak
- Andrzej Czyżewski
2016
Results of investigation of face detection algorithms in the video sequences are presented in the paper. The recordings were made with a miniature industrial USB camera in real conditions met in three bank operating rooms. The aim of the experiments was to check the practical usability of the face detection method in the biometric bank client verification system. The main assumption was to provide as much as possible user interaction with the application. Applied algorithms for face detection were described and results of the efficiency of face detection in the real bank environment conditions were presented and discussed.
Face detection in image sequences using a portable thermal camera
- Alicja Kwaśniewska
- Jacek Rumiński
2016
Face detection is often a first step in quantitative analysis of face images. It is an important research area for visible images and recently also for thermography. Due to technological developments thermal cameras may be embedded into wearable devices to provide remote healthcare. In this paper, we compared three algorithms for face detection in thermal images by testing execution time, accuracy, symmetry ratio and false-positives. We investigated whether the computational performance of the methods allows for reliable face detection in real-time. The results show that the best algorithm allows to detect faces with acceptable accuracy (90.5±4.34%) in about 23ms per frame.
FACES OF MODERNISM - URBAN PLANNING OF SOCIAL HOUSING ESTATES IN GDANSK AND HAMBURG-ALTONA
- Małgorzata Kostrzewska
2016 Full text
The paper aims to compare the modernistic social housing estates built during the interwar period in the Free City of Gdansk and in Altona, the small neighbour of Hamburg. The comparison is based on the analysis of the factors, which significantly affected the decisions regarding spatial transformations and the development of both cities in that time. These factors include primarily: poor living conditions, resulting from the explosive growth of cities and industry at the turn of the 19th and 20th century; growing popularity of the Howard’s “garden-city” idea and emerging new architectural style – Modernism and its interpretations; tradition of German brick architecture; personalities of Hugo Althoff (in Gdansk) and Gustav Oelsner (in Altona), the authors of the new cities’ development plans, urban and architectural designs; their ideological background and professional experience they mostly shared; political context and connections of both cities with the German Reich; development of housing cooperatives and social housing; growing role of urban green, recreation, and sport areas. The comparison shows that despite many differences, such as the political situation, history, or the approach to spatial planning (in Gdansk – construction of new neighbourhoods and housing complexes on greenfield; in Altona – also complementing the existing city buildings with the new housing developments), the effect has often been similar for a number of attributes. Social housing estates of Gdansk and Altona are connected to the idea of caring for healthy living conditions, access of sunlight and air, creative use of the “garden-city” idea. The attempt to realization of the demands of Modernism while preserving architectural and urban tradition, despite different urban and architectural solutions, is common as well. Althoff and Oelsner were characterised by social awareness, aesthetic sensitivity, and a certain amount of visionary reaching many years ahead. Implementation of short-term political purposes was not their intention. The social housing estates from the 20s and 30s enrich the space of modern Gdansk and Hamburg-Altona constantly recalling the value of the social function of the city.
Facing the brainstorming theory. A case of requirements elicitation
- Paweł Weichbroth
2016 Full text Studia Ekonomiczne. Zeszyty Naukowe Uniwersytetu Ekonomicznego w Katowicach
Knowledge is still considered to be power and its externalization makes it possible for others to use that power. In this paper, we examine the theory of brainstorming, and the claim by father Alex Osborn that in a group session an individual can think of twice as many ideas than working alone. In the context of requirements elicitation, we performed an experiment on a “nominal” and a “real” group of participants, following a procedure based on the Jaccard index. However, the obtained results do not provide evidence to support the above opinion, because during a five-minute session, participants working individually produce over 43% more ideas than a group of different participants.
Fading Modelling in Dynamic Off-Body Channels
- Sławomir Ambroziak
- Kenan Turbić
- Carla Oliveira
- Luis M. Correia
- Ryszard Katulski
2016
This paper presents an off-body fading channel model for Body Area Networks. The proposed model, based on both simulations and measurements at 2.45 GHz in a realistic indoor environment, consists of three components: mean path loss, body shadowing, and multipath fading. The first is modelled as a log function of distance, the path loss exponent being in between 0.4 and 1.6. A statistical perspective is taken for the other two components, i.e., body shadowing is modelled by a Lognormal Distribution, and multipath fading by Rice or Nakagami-m Distributions, depending on body motion characteristics. The correlation between selected distributions and empirical data is always higher than 0.95, typically being greater than 0.98. This model takes the statistical influence of various parameters and features present in BANs into account.
Fast EM-driven optimization using variable-fidelity EM models and adjoint sensitivities
- Sławomir Kozieł
- Adrian Bekasiewicz
2016 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
A robust and computationally efficient technique for microwave design optimization is presented. Our approach exploits variable-fidelity electromagnetic (EM) simulation models and adjoint sensitivities. The low-fidelity EM model correction is realized by means of space mapping (SM). In the optimization process, the SM parameters are optimized together with the design itself, which allows us to keep the number of both low- and high-fidelity simulations at low levels. The algorithm is demonstrated using two examples. Experimental validation is also provided.
Fast Full-Wave Multilevel Zero-Pole Optimization of Microwave Filters
- Natalia Leszczynska
- Adam Lamęcki
- Michał Mrozowski
2016 IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
A new concept is proposed for the full-wave computer-aided design of microwave filters. The method consists of two stages and operates on the zeros and poles of the transfer function and their derivatives. These quantities are evaluated from the response computed by a full-wave electromagnetic solver with two levels of accuracy. The two stages make use of different models that are optimized using a low-accuracy electromagnetic solver. The design involves one coarse-level optimization in the first stage and a few iterations in the second stage, each requiring a single computation of a high-accuracy response. The effectiveness of the proposed technique is demonstrated with two examples, in which design closure was achieved with just three evaluations of the high-accuracy full-wave solutions irrespective of the quality of the initial design.
Fast geometry scaling of UWB band-notch antennas
- Sławomir Kozieł
- Adrian Bekasiewicz
2016
Implementation of band-notch capability plays an important role in the design of ultra-wideband (UWB) antennas. At the same time, appropriate sizing of antenna geometry parameters in order to precisely allocate the notch at the required frequency as well as to ensure sufficient reflection level is quite challenging and has to be based—for reliability reasons—on full-wave electromagnetic (EM) simulations of the structure. In this paper, we propose a simple technique for dimension scaling of UWB antennas that allows rapid re-allocation of the band-notch for a required frequency. Our approach exploits a fast inverse model established using several reference designs obtained for coarse-discretization EM model of the antenna of interest as well as appropriate correction techniques that allows us to apply the model for antenna scaling at high-fidelity EM simulation level. The proposed procedure is demonstrated using a compact UWB monopole with the band-notch scaling range from 5 GHz to 8 GHz.
Fast simulation-driven design optimization of UWB band-notch antennas
- Sławomir Kozieł
- Adrian Bekasiewicz
2016 IEEE Antennas and Wireless Propagation Letters
In this letter, a simple yet reliable and automated methodology for rapid design optimization of ultra-wideband (UWB) band-notch antennas is presented. Our approach is a two-stage procedure with the first stage focused on the design of the antenna itself, and the secondstage aiming at identification of the appropriate dimensions of the resonator with the purpose of allocating the band-notch in the desired frequency range. For the sake of computational efficiency, both stages are realized using surrogate-based optimization principles. The proposed technique is demonstrated usingtwo UWB antenna examples with a lower and an upper WLAN band-notch, respectively. In both cases, the final designs are obtained at a cost corresponding to less than 30 evaluations of the high-fidelity EM model of the respective structure. Experimental validation of the fabricated proto-types is also provided.
Fast surrogate-assisted simulation-driven design of compact microwave hybrid couplers
- Piotr Kurgan
- Sławomir Kozieł
2016 ENGINEERING OPTIMIZATION
This work presents a robust methodology for expedited simulation-driven design optimization of compact microwave hybrid couplers. The technique relies on problem decomposition, and a bot-tom–up design strategy, starting from the level of basic building blocks of the coupler, and finishing with a tuning procedure that exploits a fast surrogate model of the entire structure. The latter is constructed by cascading local response surface approximations of coupler elementary elements. The cross-coupling effects within the structure are neglected in the first stage of the design process; however, they are accounted for in the tuning phase by means of space-mapping correction of the surrogate. The proposed approach is demonstrated through the design of a compact rat-race and two branch-line couplers. In all cases, the computational cost of the optimization process is very low and corresponds to just a few high-fidelity electromagnetic simulations of respective structures. Experimental validation is also provided.
FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
- Ewelina Korol
- Andrzej Tejchman-Konarzewski
2016
The numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations cross-correlated random fields were used to describe the spatial fluctuation of material randomness. Stochastic simulations were made with varying uniaxial tensile strength, initial fracture energy and elastic modulus. The effect of independently and simultaneously varying material parameter was investigated.
Fe local structure in Pt-free nitrogen-modified carbon based electrocatalysts: XAFS study
- Agnieszka Witkowska
- Gabriele Giuli
- Marco Renzi
- Francesco Nobili
- Mariangela Longhi
2016 Full text Journal of Physics : Conference Series
The paper presents a new results on the bonding environment (coordination number and geometry) and on oxidation states of Fe in nitrogen-modified Fe/C composites used as Pt-free catalysts for oxygen reduction in Direct Hydrogen Fuel Cells. Starting from glucose or fructose, two catalysts displaying different electrochemical performance were prepared and studied in the form of pristine powder and thin catalytic layer of electrode by Fe K-edge XAFS spectroscopy. The results show how the Fe local structure varies as a function of different synthesis conditions and how changes in the structural properties of the catalysts are related to fuel cell electrochemical performance increase during a cell activation period.
Feature Reduction Using Similarity Measure in Object Detector Learning with Haar-like Features
- Jerzy Dembski
2016
This paper presents two methods of training complexity reduction by additional selection of features to check in object detector training task by AdaBoost training algorithm. In the first method, the features with weak performance at first weak classifier building process are reduced based on a list of features sorted by minimum weighted error. In the second method the feature similarity measures are used to throw away that features which is similar to earlier checked features with high minimum error rates in possible weak classifiers for current step. Experimental results with MIT-CMU $19\times19$ face detection images show that the error presented by ROC curves is near the same for the learning with and without additional feature reduction during the computational complexity is well reduced.
Features extraction from the electrocatalytic gas sensor responses
- Paweł Kalinowski
- Łukasz Woźniak
- Maria Stachowiak
- Grzegorz Jasiński
- Piotr Jasiński
2016
One of the types of gas sensors used for detection and identification of toxic-air pollutant is an electrocatalytic gas sensor. The electrocatalytic sensors are working in cyclic voltammetry mode, enable detection of various gases. Their response are in the form of I-V curves which contain information about the type and the concentration of measured volatile compound. However, additional analysis is required to provide the efficient recognition of the target gas. Multivariate data analysis and pattern rec ognition methods are proven to be useful tool for such application, but further investigations on the improvement of the sensor’s responses processing are required. In this article the method for extraction of the parameters from the electrocatalytic sensor responses is presented. Extracted features enable the significant reduction of data dimension without the loss of the efficiency of recognition of four volatile air-pollutant, namely nitrogen dioxide, ammonia, hydrogen sulfide and sulfur dioxide.
FERMENTACJA METANOWA MODELOWEGO WSADU KOMUNALNYCH ODPADÓW ORGANICZNYCH
- Nikola Julia Śniadecka
- Aleksandra Głogowska
- Aleksandra Korkosz
- Andrzej Tonderski
- Jan Hupka
2016
Fermentacja metanowa frakcji organicznej odpadów komunalnych pozwala na efektywny odzysk węgla z odpadów. Procesem beztlenowym jest zasadniczo fermentacja metanowa mezofilowa, jak i termofilowa, jednakże w procesie fermentacji termofilowej redukcja związków organicznych, niszczenie patogenów oraz produkcja biogazu zachodzi z większą wydajnością. Odpady komunalne charakteryzują się wysoką heterogenicznością składu, co może przyczyniać się do zakłócenia procesów biologicznych. Istotnym kryterium doboru technologii odzysku biofrakcji jest bilans jakościowy oraz skład surowcowy przetwarzanych odpadów komunalnych. W omawianej pracy na podstawie badań morfologii odpadów komunalnych skomponowano wsad modelowy do bioreaktorów zapewniający powtarzalność poszczególnych doświadczeń fermentacji metanowej, z minimalizacją obecności substancji mogących inhibować proces.
Fiber optic displacement sensor with signal analysis in spectral domain
- Katarzyna Karpienko
- Marcin Marzejon
- Jerzy Pluciński
2016
In this paper, a study of a low-coherence fiber optic displacement sensor is presented. The sensor consisted of a broadband source whose central wavelength was either at 1310 nm or 1550 nm, a sensing Fabry-Pérot interferometer operating in reflective mode and an optical spectrum analyzer acting as the detection setup. All these components were connected by a single-mode fiber coupler. Metrological parameters of the sensor were investigated for different lengths of the fiber connecting the sensing Fabry-Pérot interferometer (1 m and 10 m). For each length of the fiber, displacement in the range of 0 μm to 500 μm, in increments of 50 μm were measured. Obtained results indicate that the developed sensor is not sensitive to changes in attenuation in the optical path, thus enabling remote measurement of the displacement on long distances while maintaining a satisfactory accuracy.
Fiber optic low-coherence Fabry-Pérot interferometer with ZnO layers in transmission and reflective mode: comparative study
- Daria Majchrowicz
- Marzena Hirsch
2016
A construction of a low-coherence fiber-optic Fabry-Pérot interferometer using a thin ZnO layer as a reflective surfaces was proposed and examined. In the investigated setup, the ZnO layer of thickness 200 nm were deposited on the face of the standard telecommunication single-mode optical fiber (SMF-28). Measurements of interference signal were performed for the interferometer working in the transmission and reflective mode, as well. The measurements were performed for two wavelength (1300 nm and 1550 nm) for various length of the air cavity. The optimal parameters of the Fabry-Pérot cavity was chosen for achieving the best visibility of the interference signal in the both modes. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Fiber-optic Fabry-Pérot sensors – modeling versus measurements results
- Jerzy Pluciński
- Katarzyna Karpienko
2016
This paper describes how parameters of investigated substances and the fiber-optic Fabry-Pérot sensing interferometer affect the spectrum of the optical radiation at the output of the sensor. First, the modeling of the operation of the sensing interferometer was conducted. Most important parameters and effects that were taken into account are: dependences of the refractive indices of the core and the cladding, as well the mode field diameter of a single mode fiber on the wavelength, changes in the parameters of an optical beam inside the interferometer caused by refractive index and the absorption of the medium inside the cavity, including the intensity of the beam, the beam diameter, the beam divergence, the curvature of the wavefront, and the phase shift caused by the Gouy effect. Impact of these parameters and effects on the spectrum of the optical radiation at the output of the sensor was subsequently investigated. Following, spectra from selected Fabry-Pérot optical sensors, applied to measurement of refractive index, were presented. Measurement results were compared with the spectra obtained by modeling
Field-induced suppression of charge density wave in GdNiC2
- Kamil Kolincio
- Karolina Górnicka
- Michał Jerzy Winiarski
- Judyta Strychalska-Nowak
- Tomasz Klimczuk
2016 Full text PHYSICAL REVIEW B
We report the specific heat, magnetic, magnetotransport, and galvanomagnetic properties of polycrystalline GdNiC 2 . In the intermediate temperature region above T N = 20 K, we observe large negative magnetoresistance due to Zeeman splitting of the electronic bands and partial destruction of a charge density wave ground state. Our magnetoresistance and Hall measurements show that at low temperatures a magnetic field-induced transformation from antiferromagnetic order to a metamagnetic phase results in the partial suppression of the CDW.
Filozofia Polska szuka swojego miejsca.
- Andrzej Lisak
2016 Prakseologia
Tekst poświęcony jest sytuacji w filozofii a w filozofii polskiej w szczególności w kontekście krytycznej analizy pracy Filozofia 2.0. Paradygmaty i strategie. Punktem wyjścia rozważań jest z jednej strony filozoficzna diagnoza współczesności (analizującą jej ukierunkowanie na konsumpcję i działania instrumentalne, unieważniające refleksyjność) zwłaszcza w jej polskich uwarunkowaniach a celem analiza rozlicznych diagnoz, jakie braki kultury współczesnej może filozofia wypełnić. Rozważa się tu kondycję filozofii współczesnej w jej najróżniejszych aspektach, jej diagnozę, analizę jej zagrożeń, jej cele, zadania i perspektywy. Zwraca się uwagę na zasadniczą cechę filozofii, jej autorefleksyjność, na to, żejest poszukiwaniem mądrości (a więc ideą integracji całej duchowej sfery człowieka, rozważaniem nie tylko środków a celów). Odsłania się jej funkcję krytyczną wobec społeczeństwa i kultury, ale też wobec niej samej. Wskazuje sie na jej pierwotne źródło: poznaj samego siebie, jej funkcję refleksyjną, jej dialogiczny charakter., jej psychoterapeutyczne znaczenie. Wskazuję tu tylko wybrane aspekty pracy. Całość przedstawionych w tekście analiz pozwala zarysowane cele przeanalizować we wszachstronny sposób.