2019 - Repozytorium publikacji - Politechnika Gdańska

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Soft-decision schemes for radar estimation of elevation at low grazing angles
- Michał Meller
- Kamil Stawiarski
2019 Pełny tekst IET Radar Sonar and Navigation
In modern radars, the problem of estimating elevation angle at low grazing angles is typically solved using superresolution techniques. These techniques often require one to provide an estimate of the number of waveforms impinging the array, which one can accomplish using model selection techniques. In this paper, we investigate the performance of an alternative approach, based on the Bayesian-like model averaging. The Bayesian approach exploits the fact that the parameters of the model related to multipath signals are nuisance ones, which allows one to avoid the estimation of the number of waveforms and improves estimation performance. The method is introduced for the classical conditional maximum likelihood estimator and extended to its, recently proposed, robustified version. We find, however, that the robustified estimator includes its own soft-decision mechanism and benefits from the averaging only for low levels of model uncertainty.
Software development methodologies and practices in start-ups
- Muhammad Ahmad
2019 Pełny tekst IET Software
Software start-ups are aiming to develop cutting-edge software products under highly uncertain conditions, overcoming fast-growing markets under multiple influences. This study aims to identify and analyse the existing scientific literature regarding software development methodologies and practices in software start-ups published between January 2006 and December 2017 using the systematic mapping study. The results identified 37 relevant primary studies out of 1982 papers. To validate the results from the mapping study, an empirical study was based on the research data collected from 14 real-life software start-ups located in Finland, Italy and Norway. The result shows that Agile and Lean start-up methodologies are the most commonly used in software start-ups due to the flexible nature and easy tailoring. A total of 144 software development work practices are extracted from the primary studies. This study contributes to the research in several ways: (i) provides state of the art regarding software development methods and practices in software start-up contexts, (ii) reports commonly used methods along with its benefits identified in primary studies and (iii) identifies opportunities for future software start-up research.
Software Factory project for enhancement of student experiential learning
- Muhammad Ahmad
- Kari Liukkunen
2019
Providing opportunities for students to work on real-world software development projects for real customers is critical to prepare students for the IT industry. Such projects help students to understand what they will face in the industry and experience real customer interaction and challenges in collaborative work. To provide this opportunity in an academic environment and enhance the learning and multicultural teamwork experience, the University of Oulu, Finland offers the software factory (SWF) project. This paper presents the design of the SWF course and the learning environment and assessment techniques, and it discusses the importance of reflective learning diaries and serious games. Additionally, this paper examines factors in the SWF learning environment that affect student learning in the SWF course. Survey data were collected from the last six years of SWF projects. The results show that students consider the SWF to be a good collaborative learning environment that helps them achieve academic triumphs and enhances various professional skills. The learning diaries are effective for increasing students’ learning experiences as well as providing an opportunity for teaching staff to monitor students’ progress and offer better facilitation. These results are helpful for academic institutions and industry when developing such a learning environment.
Solid Phase Microextraction: Apparatus, Sorbent Materials, and Application.
- Muhammad Sajid
- Małgorzata Rutkowska
- Natalia Jatkowska
- Jacek Namieśnik
- Justyna Płotka-Wasylka
2019 Pełny tekst CRITICAL REVIEWS IN ANALYTICAL CHEMISTRY
he primary objective of this review article is to strategically screen and highlight the advancements in the area of solid phase microextraction (SPME). The plenty of review articles have been written on different aspects of SPME, this review is dedicated to provide the brief but clear overview of the research footprints so produced from SPME. Some of the key advancements in types and designs, coating materials, coating strategies, in vivo sampling and direct coupling of SPME with MS have been critically discussed.
Solid state versus fiber picosecond infrared lasers applied to two-photon vision tests
- Marcin Marzejon
- Katarzyna Komar
- Łukasz Kornaszewski
- Maciej Wojtkowski
2019 Proceedings of SPIE
Development of new microperimetric tools dedicated for imaging of early functional changes in the retina may help in the monitoring of various ocular diseases progression e.g. Age-Related Macular Degeneration. Recently described two-photon vision may be applied to microperimetric devices. Many subjects with well-known disease history could be investigated with newly developed instrumentation that tests ability of human eye to perceive near infrared radiation. The main limitation of this new method is a very high cost of the femtosecond laser. Facing this problem, we try to replace the femtosecond laser with lower cost fiber-optic picosecond light source. To compare these two lasers, we constructed dedicated measurement system. We performed measurements of two-photon vision threshold on healthy subjects for two different light sources - sub picosecond Kerr mode-locking solid-state laser and fiber-based picosecond laser. Experiments were conducted for an open circle flickering stimulus with 0.5 deg. diameter, for retinal locations varying from 0 deg. to 5.8 deg., using 4-2-1 threshold strategy that is well-known from classical microperimetry. Values of obtained thresholds are only 5 times higher for the fiber laser than that obtained by using the femtosecond laser, while it was expected to be about over 16 times higher. This fact requires further investigations. Nevertheless, the idea of replacement of the latter laser by relatively cheap fiber-optic one in ophthalmic devices for two-photon vision studies seems to be potentially promising.
Solvent-Free Synthesis of Phosphonic Graphene Derivative and Its Application in Mercury Ions Adsorption
- Robert Stanisław Olszewski
- Małgorzata Nadolska
- Marcin Stanisław Łapiński
- Marta Prześniak-Welenc
- Bartłomiej Cieślik
- Kamila Sadowska
2019 Pełny tekst Nanomaterials
Functionalized graphene was efficiently prepared through ball-milling of graphite in the presence of dry ice. In this way, oxygen functional groups were introduced into material. The material was further chemically functionalized to produce graphene derivative with phosphonic groups. The obtained materials were characterized by spectroscopic and microscopic methods, along with thermogravimetric analysis. The newly developed material was used as an efficient mercury adsorbent, showing high adsorption efficiency. The adsorption isotherms were fitted using Freundlich and Langmuir models. The adsorption kinetics were fitted with pseudo-first order and pseudo-second order models. Adsorption selectivity was determined in the presence of cadmium ions and nickel ions. The presence of mentioned bivalent ions in the solution did not affect mercury adsorption efficiency.
Some Artificial Intelligence Driven Algorithms For Mobile Edge Computing in Smart City
- Jerzy Balicki
- Piotr Dryja
- Marcin Zakidalski
2019
Smart mobile devices can share computing workload with the computer cloud that is important when artificial intelligence tools support computer systems in a smart city. This concept brings computing on the edge of the cloud, closer to citizens and it can shorten latency. Edge computing removes a crucial drawback of the smart city computing because city services are usually far away from citizens, physically. Besides, we introduced a neuro-evolution approach for supporting smart infrastructures. Solutions related to using Tweeter’s blogs by smart city apps are presented, too. Finally, the design principles of differential evolution for smart city are analyzed.
Sonocatalytic degradation of tetracycline antibiotic using zinc oxide nanostructures loaded on nano-cellulose from waste straw as nanosonocatalyst
- Reza Soltani
- Masumeh Mashayekhi
- Masumeh Naderi
- Grzegorz Boczkaj
- Sahand Jorfi
- Mahdi Safari
2019 ULTRASONICS SONOCHEMISTRY
The aim of the present investigation was the combination of ZnO nanostructures with nano-cellulose (NC) for the efficient degradation of tetracycline (TC) antibiotic under ultrasonic irradiation. The removal efficiency of 12.8% was obtained by the sole use of ultrasound (US), while the removal efficiency increased up to 70% by the US/ZnO treatment process. Due to the integration of ZnO nanostructures with NC, the removal efficiency of 87.6% was obtained within 45 min. The removal efficiency substantially decreased in the presence of tert-butyl alcohol (more than 25% reduction), indicating that radOH-mediation oxidation is responsible for the degradation of TC molecules. Peroxymonosulfate (PMS) led to the most enhancing effect on the removal of TC among percarbonate, persulfate and periodate ions. The addition of PMS caused the degradation efficiency of 96.4% within the short contact time of 15 min. The bio-toxicity examination on the basis of inhibition test conducted on activated sludge revealed diminishing the oxygen consumption inhibition percent [IOUR (%)] from 33.6 to 22.1% during the US/ZnO/NC process. Consequently, the utilization of the US/ZnO/NC process can convert TC molecules to less toxic compounds. However, longer reaction time is required for complete conversion into non-toxic substances.
Sound engineering as our commitment to its creators in Poland
- Bożena Kostek
- Andrzej Czyżewski
2019 Archives of Acoustics
Sound engineering is an interdisciplinary and rapidly expanding domain. It covers many aspects, such as sound perception, studio and sound mastering technology, music information retrieval including content-based search systems and automatic music transcription frameworks, sound synthesis, sound restoration, electroacoustics, and other ones constituting multimedia technology. Moreover, machine learning methods applied to the topics mentioned above become a substantial part of sound engineering. The state-of-the-art of these topics is shortly covered by this talk. History of the development of sound engineering within the last decades is briefly outlined. A contribution of Gdańsk University of Technology (GUT) pioneering researchers to the development of sound engineering is shortly characterized. A decisive influence of Professors Sankiewicz’s and Budzyński’s initiative and achievements on the growth of the Multimedia Systems Department and Audio Acoustics Laboratory of Gdańsk University of Technology is demonstrated. Some key events concerning founding the Polish Section of the Audio Engineering Society are also recalled.
Sources of inspiration in designing ecological buildings. If not Pinterest than what?
- Katarzyna Zielonko-Jung
- Ziemowit Belter
2019 Pełny tekst Architectus
Efficiency of ecological measures for sustainable architecture depends greatly upon the moment in which it is defined as essential, and how early it can be applied during the design concept stage. The following article refers to inspiration, the initial stage of the design and means to combine it with substantial knowledge regarding ecological architecture. Means, such as computer programs were taken into consideration. Authors conclude that a visible void of viable tools in such regard is observable, which might lead to limited popularity of sustainable architecture in general. The article is mainly intended to evaluate the characteristic for a tool that could match the profile of ecological inspiration enhancer, and would be able to function in the reality of a complex architecture market. An assessment of two internet platforms was conducted for this purpose, namely Pinterest and Palette 2030. Pinterest, although not dedicated only to architects, found its way to the architects tool box thanks to its popularity among clients. Palette 2030, on the other hand, is a professional internet database that allows architects to access ecological knowledge at the early stage of the design process. Conclusions combine specific characteristics of both platforms in a way that would allow to estimate, if any potential solution for a tool with which to encourage smart, ecological solutions is possible
Spatial distribution of pharmaceuticals in conventional wastewater treatment plant with Sludge Treatment Reed Beds technology
- Katarzyna Kołecka
- Magdalena Gajewska
- Piotr Stepnowski
- Magda Caban
2019 Pełny tekst SCIENCE OF THE TOTAL ENVIRONMENT
Pharmaceutical residues are an emerging environmental problem. It is strongly confirmed that pharmaceuticals are present in soils and environmental waters (surface, marine and even groundwater), and that wastewater treatment plant (WWTP) effluents are the main source of pharmaceuticals in the watershed. The aim of this studywas to recognize the spatial distribution and seasonal changes of selected pharmaceuticals in conventional WWTP with Sludge Treatment Reed Beds (STRBs) technology used for dewatering and stabilization of sewage sludge, because these systems have never been studied in terms of pharmaceuticals distribution or removal potential. The researchwas conducted in conventionalWWTP in Gniewino, where raw wastewaterwas treated usingmechanical, biological and chemical removal of the organic matter and nutrients, and sewage sludge was treated with STRB. Determinations of pharmaceuticals (non-steroidal anti-inflammatory drugs - ibuprofen, paracetamol, flurbiprofen, naproxen, diclofenac and its metabolites) and basic parameters were carried out in samples of influent and effluent fromWWTP and in the liquid phase of surplus activated sludge (SAS) aswell as rejectwater from STRB. The potential of removal varied among target pharmaceuticals. Ibuprofen and naproxen were completely removed by the standard applied technology of the Gniewino WWTP. Diclofenac and its metabolites were the chemicals with the lowest removal potential in wastewater and the highest detection frequency. These pharmaceuticals were also detected in the liquid phase of SAS as well as in reject water. However, removal potential when using STRB was higher than 94% (mostly higher than 99%), independent of the season. Indeed, the STRB technology is not only efficient in sludge dewatering and nutrient removal (primary purpose), but also elimination of polar pollutants. Nevertheless, removal in STRB did not mean that pharmaceuticals were totally eliminated because these compounds could be “trapped and stored” in beds (by the process of sorption) or transformed into other products. This study is a starting point for further exploration of STRB technology for elimination of emerging pollutants.
Spatiotemporal dynamics of the active perirheic zone in a natural wetland floodplain
- Tomasz Berezowski
- D. Partington
- Jarosław Chormański
- Okke Batelaan
2019 Pełny tekst WATER RESOURCES RESEARCH
Abstract The ecologically and biogeochemically significant perirheic zone is a part of the floodplain where waters originating from both the river and adjacent floodplain are present. In this study, we investigate the spatiotemporal dynamics of the active perirheic zone, i.e. river and floodplain waters and their transient mixing extent. This is achieved by using the Hydraulic Mixing-Cell method, a complement to a fully integrated surface-subsurface hydrological model, in the Biebrza catchment, north-east Poland. The model performance is verified against hydrological and hydrochemical datasets. The simulations show that overbank flooding river water is unable to penetrate deeply into the floodplain due to the presence of floodplain water. However, the active perirheic zone moves towards the floodplain and back within a buffer of at least one kilometer from its initial position located approximately 0 to 2.5 km from the Biebrza River. The active perirheic zone is also present further away from the river due to the discharge of tributaries and surface runoff. The active perirheic zone exhibits multi-directional movement, and can reappear in different places after a period of time. Effectively, during the flooding period, the active perirheic zone moves over 38% of the floodplain area, while the maximum daily extent is 24% of the floodplain. These dynamics imply that biogeochemical processes related to the perirheic zone, e.g. denitrification, also vary in space and time. Due to the strong correlation of the perirheic zone extent with the meteorologically dependent variables, especially the snowmelt water extent, it is vulnerable to climate change.
Special techniques and future perspectives: Simultaneous macro- and micro-electrode recordings
- Michał Tomasz Kucewicz
- Brent M. Berry
- Gregory A. Worrell
2019
There are many approaches to studying the inner workings of the brain and its highly interconnected circuits. One can look at the global activity in different brain structures using non-invasive technologies like positron emission tomography (PET) or functional magnetic resonance imaging (fMRI), which measure physiological changes, e.g. in the glucose uptake or blood flow. These can be very effectively used to localize active patches of brain tissue with up to millimeter-scale resolution but provide limited insight into the processes underlying this activity. At the heart of brain processes lies synchronized activity of neurons, neuronal assemblies and the wide-spread connections of neuronal networks, which give rise to the electrical activity recorded in the scalp electroencephalogram (EEG), cortical field oscillations in the electrocorticogram (ECoG), and the local field potential (LFP) and action potentials. This large scale of brain electrophysiology across a wide range of spatial and temporal scales presents significant technical challenges for the methods used to probe the activity of neural networks.
Specification of private art galleries used in the central part of old town Belgrade
- Anna Stasiak
2019 Pełny tekst Przestrzeń i Forma
In Belgrade, since the late 1990s, private art galleries have appeared that indirectly create the image of the city through the propagation of art, take part in the education process of the residents and undertake criticism of local and global events. The article is an answer to the following questions: [1] why and how do the bottom-up art oriented places appear in Belgrade, [2] how do they function, and (3) what is their architectural form, and (4) why this form is just like that
SPECTRAL DYNAMIC ANALYSIS OF A STATIONARY JACK-UP PLATFORM
- Bogdan Rozmarynowski
2019 Pełny tekst Polish Maritime Research
The paper refers to the dynamic short-term response analysis of the Baltic steel drilling platform (see Fig.2) in a random sea-state represented by one-dimensional wave spectrum proposed by Striekalov and Massel and it is recommended for the Baltic Sea area. The Baltic drilling platform is a jack-up type platform for the exploration and exploitation of oil under the Baltic Sea. The analysis presented deals with the stationary phase of the platform life when the legs are fixed in the sea bottom. The submerged elements of jack-up platforms are relatively slender, thus a modified Morison equation to assess the in-line wave forces is justified here. The application of frequency transfer functions in offshore vibration systems leads to structural response spectra, whose input is defined by the wave elevation and wind velocity spectra. The analysis can be applied also to support structures for offshore wind turbines.
Speech Analytics Based on Machine Learning
- Grazina Korvel
- Adam Kurowski
- Bożena Kostek
- Andrzej Czyżewski
2019
In this chapter, the process of speech data preparation for machine learning is discussed in detail. Examples of speech analytics methods applied to phonemes and allophones are shown. Further, an approach to automatic phoneme recognition involving optimized parametrization and a classifier belonging to machine learning algorithms is discussed. Feature vectors are built on the basis of descriptors coming from the music information retrieval (MIR) domain. Then, phoneme classification beyond the typically used techniques is extended towards exploring Deep Neural Networks (DNNs). This is done by combining Convolutional Neural Networks (CNNs) with audio data converted to the time-frequency space domain (i.e. spectrograms) and then exported as images. In this way a two-dimensional representation of speech feature space is employed. When preparing the phoneme dataset for CNNs, zero padding and interpolation techniques are used. The obtained results show an improvement in classification accuracy in the case of allophones of the phoneme /l/, when CNNs coupled with spectrogram representation are employed. Contrarily, in the case of vowel classification, the results are better for the approach based on pre-selected features and a conventional machine learning algorithm.
Sphere Drive and Control System for Haptic Interaction With Physical, Virtual, and Augmented Reality
- Zdzisław Kowalczuk
- Marek Tatara
2019 Pełny tekst IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
A system for haptic interaction with physical, virtual, and augmented realities, founded on drive and measurement elements (DMEs), is considered. The system consists of eight DME rolls equipped with linear actuators, able to measure their angular velocity, drive the sphere, and adjust downforce (pressing the roll against the sphere). Two modeling issues are addressed. Special effort is put in to compensate for various technical issues. Analytic derivation of the relation between the angular velocities of the rolls and the sphere is presented. On this basis, the importance of control over the downforce applied to an individual roll is indicated with the aim of minimizing the wear of the roll. The selection of the proper downforce for each specific position (angle) of a DME roll can extend its life cycle by reducing its grinding on the sphere. The issue of modeling the relation between the angular velocity of a given DME and the sphere is addressed. In a simplified case, such a relation can be obtained analytically. However, for a nonuniform distribution of reaction forces on the contact area, a numerical approach is necessary. Two numerical methods for the estimation of the angular velocity of the DME roll are presented and discussed. Moreover, an algorithm for the estimation of the sphere's rotational motion parameters is described and implemented, proving the usefulness of the presented method.
Sposoby przykładania obciążenia zmiennego na konstrukcję płytowo-słupową
- Andrzej Ambroziak
- Maciej Grabski
2019 Materiały Budowlane
W pracy przedstawiono analizę porównawczą wybranych metod zadawania obciążenia zmiennego na konstrukcje płytowo-słupową. Przeanalizowano pięć sposobów rozkładu obciążenia na płytę stropową. Wyniki momentów zginających i przemieszczeń w wybranych punktach dla analizowanych przypadków porównywano z wartościami ekstremalnymi obliczonymi na podstawie powierzchni wpływu (Wariant 1). Wykonane obliczenia pozwoliły na wskazanie zalecanej metody rozkładu obciążenia zmiennego na płytę stropową w konstrukcji płyta-słup.
Sprawiedliwość agrarna
- Andrzej Karalus
2019 Pełny tekst Archiwum Historii Filozofii i Myśli Społecznej
prawiedliwość agrarna została napisana z intencją zreformowania stosunków społeczno-politycznych. Tekst opiera się na założeniu wywodzącym się z tradycji prawnonaturalnej, które brzmi, iż pierwotnie każdy był współwłaścicielem powierzchni Ziemi. Powstanie prywatnej własności ziemskiej (czyli, eo ipso, wywłaszczenie większości ludzi) należy zakwalifikować jako akt bezprawia, kumulujący się w historycznie nawarstwionych nierównościach społecznych i spychający części populacji w stan chronicznej nędzy. Skoro likwidacja własności prywatnej i powrót do pierwotnej własności gromadzkiej jest niewskazany (z uwagi na to, że wartość ziemi zrosła się z wprowadzonymi na niej ulepszeniami), jedynym sposobem materialnego i godnościowego zadośćuczynienia za akt wywłaszczenia pozostaje, po pierwsze, wprowadzenie podatku od spadku w celu sfinansowania bezwarunkowej i jednorazowej renty gruntowej, wypłacanej każdemu bez względu na stan posiadania po ukończeniu 21 roku życia w wysokości odpowiadającej wartości zagarniętej ziemi (15 funtów szterlingów,), oraz, po drugie, wypłacania corocznie 10 funtów szterlingów chorym, kalekom oraz tym wszystkim, którzy ukończyli pięćdziesiąty rok życia. Paine przytacza szereg argumentów na poparcie swojego projektu redystrybucji (argument prawnonaturalny, utylitarystyczny, deontologiczny), omawia również w jaki sposób należałoby go wdrożyć.
Sprawiedliwość agrarna Thomasa Paine’a i narodziny dyskursu egalitarnego
- Andrzej Karalus
2019 Pełny tekst Archiwum Historii Filozofii i Myśli Społecznej
Thomas Paine napisał Sprawiedliwość agrarną we Francji w roku 1796 w szczycie posttermidoriańskiego zamętu, krótko po wprowadzeniu Konstytucji Roku III. W swoim ostatnim wielkim pamflecie domaga się opodatkowania wielkich właścicieli ziemskich i pomoc biednym oraz wywłaszczonym. Artykuł krótko omawia propozycję Paine i analizuje jego strukturę argumentacyjną. Stawiam w niej tezę, że Paine nie do końca świadomie przechodzi od dowodu prawnonaturalnego (sprawiedliwość agrarna jako odszkodowanie za naruszenie niezbywalnego prawa każdego człowieka do części ziemi uprawnej, które wywodzi się z pierwotnej wspólnoty własności ziemi danej nam od Boga) do argumentacji deontologicznej (bezwarunkowa renta gruntowa jako akt sprawiedliwości odszkodowawczej dla ofiar postępu cywilizacyjnego, nie akt dobroczynności), wspartej argumentacją utylitarną (ulżenie nędzy mas, stworzenie bufora ochronnego dla bogatych przez spacyfikowanie nastrojów anarchicznych). W artykule zostanie też krótko nakreślona geneza filozoficznego stanowiska Paine’a (tradycja angielskiego radykalizmu i kwakierskiego egalitaryzmu, liberalizm Locke’a). W części końcowej omówiona zostanie krótko droga recepcji idei Paine’a (zwłaszcza w kontekście bezwarunkowej renty gruntowej oraz wspólnego użytkowania ziemi i jej zasobów).