2019 - Repozytorium publikacji - Politechnika Gdańska

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Various cases of preservation and adaptive reuse Heritage Buildings in the Port of Gdynia
- Anna Orchowska-Smolińska
2019 PORTUSPlus
The port of Gdynia contains a diverse range of heritage assets, starting with its spatial layout which is an urban concept designed in the first half of the 1920s. It is important to point out, this historically-shaped harbor space is preserved in its general idea and still functioning in port activities. Another significant element is the structural, technological solution which was the basis for constructing the entire port area in a relatively short time. Finally, what we mainly identify with cultural heritage - buildings of different types, designed mostly under the influence of the Avangard Modern Movement principals, which instantly after being erected became symbols of modernity and the rebirth of Poland’s maritime power. Preserving a heritage site, which is at the same time an active port complex is a real challenge for both administrators and conservators. In this material, three widely differing realities of approach are presented towards historical tissue, from successful adaptive reuse, through radical redevelopment, to major destruction.
Vehicle detector training with minimal supervision
- Sebastian Cygert
- Andrzej Czyżewski
2019
Recently many efficient object detectors based on convolutional neural networks (CNN) have been developed and they achieved impressive performance on many computer vision tasks. However, in order to achieve practical results, CNNs require really large annotated datasets for training. While many such databases are available, many of them can only be used for research purposes. Also some problems exist where such datasets are not available at all or they are limited in scope, e.g. many robotics applications. However, it is usually possible to obtain a large set of unlabelled data which contain useful information. The above mentioned possibility justifies a development of methods that exploit unlabelled data and they work with a minimal number of required annotations. In this work we follow recent self-supervised learning paradigm. Large unlabelled dataset of traffic monitoring was acquired by the authors. Then CNN was trained in order to perform moving objects segmentation based on labels obtained from a unsupervised motionbased segmentation algorithm. Even though collected labels are not perfect, they still allow CNN to learn an efficient feature representation. In the next step we fine-tuned the CNN algorithm on a limited set of manually labelled ground-truth data for object detection. Subsequently, we investigated the relation between the number of labels used for fine-tuning and final detection performance on the test set. We also compared the results with CNN pretrained on ImageNet which is now a common technique. Vehicle detection results obtained on our custom dataset are presented in the paper. The obtained results are promising, because they demonstrate that even when only limited ground-truth data are available, it is still possible to learn efficient feature representation given large collection of unlabelled data. The presented approach seems applicable to any object detector setting where there is an access to a large set of unlabelled data with moving objects of interest.
Verification of Formulas for Periods of Adjacent Buildings Used to Assess Minimum Separation Gap Preventing Structural Pounding during Earthquakes
- S. M. Khatami
- H. Naderpour
- R.c. Barros
- Robert Jankowski
2019 Pełny tekst Advances in Civil Engineering
Insufficient separation distance between adjacent buildings may lead to serious damages during earthquakes due to structural pounding. The best way to prevent collisions is to provide sufficiently large separation distance between the structures. In this paper, the periods of two closely-spaced linear and nonlinear buildings have been investigated so as to accurately assess the minimum in-between separation gap. A new equation to calculate the effective periods of inelastic buildings has been proposed and its effectiveness has been verified through numerical analysis. The results of the investigation conducted for inelastic buildings with different number of stories indicate that the proposed formula allows us to prevent earthquake-induced structural pounding by ensuring adequate value of seismic gap.
Verification of safety in low-voltage power systems without nuisance tripping of residual current devices
- Stanisław Czapp
- Kornel Borowski
2019 ELECTRIC POWER SYSTEMS RESEARCH
Low-voltage power systems require initial and periodical verification to check the effectiveness of protection against electric shock. As a protection in case of fault, automatic disconnection of supply is most often used. To verify such a protection measure, the earth fault loop impedance or resistance is measured. This measurement is easy to perform in circuits without residual current devices. When residual current devices are installed, their unwanted tripping occurs during the measurement, and the verification becomes problematic. The paper proposes a new method of testing the effectiveness of automatic disconnection of supply, without unwanted tripping of residual current devices, especially when their rated residual current is equal to 30 mA. The theoretical background of this method, along with mathematical analysis and experimental verification are presented. The proposed method uses the testing current which is many times higher than the rated residual current of commonly used residual current devices. This is an important advantage in terms of testing accuracy.
Very high altitude micro air vehicle deployment method
- Paweł Burdziakowski
- L. Galecki
- M. Mazurkiewicz
- J. Struzinski
2019 Pełny tekst IFAC-PapersOnLine
The paper presents the original work and method for high altitude micro air vehicle deployment. The method is based on the scientific ballooning, and adapted for stratospheric flight of commercial off-the-shelf micro air vehicle in flying wing configuration. The High Altitude Micro Air Vehicle, built for this research, was deployed during a test experiment at the lower level of the stratosphere. The results of the experiment and technical details are presented. The paper concludes the experiment’s findings and delivers assumptions for the future work and next experiment.
Visual Content Learning in a Cognitive Vision Platform for Hazard Control (CVP-HC)
- Caterine Silva de Oliveira
- Cesar Sanin
- Edward Szczerbicki
2019 Pełny tekst CYBERNETICS AND SYSTEMS
This work is part of an effort for the development of a Cognitive Vision Platform for Hazard Control (CVP-HC) for applications in industrial workplaces, adaptable to a wide range of environments. The paper focuses on hazards resulted from the nonuse of personal protective equipment (PPE). Given the results of previous analysis of supervised techniques for the problem of classification of a few PPE (boots, hard hats, and gloves extracted from frames of low resolution videos), which found the Deep Learning (DL) methods as the most suitable ones to integrate our platform, the objective of this paper is to test two DL algorithms: Single Shot Detector (SSD) and Faster Region-based Convolutional Network (Faster R-CNN). The testing uses pretrained models on a second version of our PPE dataset (containing 11 classes of objects) and evaluates which of examined algorithms is more appropriate to compose our system reasoning.
Visual content representation and retrieval for Cognitive Cyber Physical Systems
- Caterine Silva de Oliveira
- Cesar Sanin
- Edward Szczerbicki
2019 Pełny tekst Procedia Computer Science
Cognitive Cyber Physical Systems have gained significant attention from academia and industry during the past few decade. One of the main reasons behind this interest is the potential of such technologies to revolutionize human life since they intend to work robustly under complex visual scenes, which environmental conditions may vary, adapting to a comprehensive range of unforeseen changes, and exhibiting prospective behavior like predicting possible visual events based on information collected from different sources. The combination of these properties aims to mimic the human capabilities and create more intelligent and efficient environments. However, preserving the environment involves gathering visual and other sensorial information and translating it into knowledge to be useful, which still remains a challenge for real time cognitive vision applications due to the complexity of such process. In this paper, we present a multi-domain knowledge structure based on experience, which can be used as a comprehensive embedded knowledge representation for Cognitive Cyber Physical System, addressing the representation of visual content issue and facilitating its reuse. The implementation of such representation has been tested in a Cognitive Vision Platform for Hazard Control (CVP-HC) to address the issue of workers’ exposure to risks in industrial environments, facilitating knowledge engineering processes through a flexible and adaptable implementation.
VISUALIZATION OF SCANTER AND ARPA RADAR DATA IN THE DISTRIBUTED TELEINFORMATION SYSTEM FOR THE BORDER GUARD
- Bartosz Czaplewski
- Sylwester Kaczmarek
- Jacek Litka
2019 Pełny tekst Zeszyty Naukowe Akademii Marynarki Wojennej
Monitoring of country maritime border is an important task of the Border Guard. This activity can be enhanced with the use of the technology enabling gathering information from distributed sources, processing of that information and its visualization. The paper presents the next stage of development of the STRADAR project (Streaming of real-time data transmission in distributed dispatching and teleinformation systems of the Border Guard), which is realized for the security and defence of the country. In the paper, storing, processing and visualization of the radar data, which is one of the tasks of the discussed scientific and research project, is described. Firstly, the general principle of radar data flow in the system was presented. Secondly, technical software description was described. Finally, radar data visualization functionality was presented.
Voltage control in a power system with renewable sources of energy
- Bartosz Tarakan
- Stanisław Czapp
- Krzysztof Dobrzyński
- Ryszard Zajczyk
- Marcin Sarnicki
2019
Intensive development of distributed generation in power systems, caused by the European Union energy policy, gives possibility for improving safety in power delivery as well as optimizing the costs of the systems functioning. In this context, distributed generation can be used for voltage control in power systems – it can be performed by the control of reactive power of each source of energy or a group of energy sources. This paper presents a method of renewable energy sources control, with the use of a supervisory control system, which operation utilizes fuzzy logic. This control system allows to improve the voltage in the power system – analyzes voltage levels at selected points of this system and affects a group of renewable energy sources.
Voltage Source Power Line Conditioner for Applications in Local Supply Systems
- Ryszard Strzelecki
- Wojciech Matelski
- Robert Małkowski
- Valentin Tomasov
- Leszek Wolski
- Antoni Krahel
2019 Pełny tekst
The paper presents the basic principles of operation of voltage source power line conditioners (VSPLC) as well as their energy and filtration properties. A 4-level cascade based Voltage Source Converter (VSC) is used as a voltage source. The advantages of this topology is relatively simple construction and simple way of balancing DC link voltages. Results of the theoretical and experimental investigations confirm good energetic and filtration properties compared to Active Power Filters (APF).
Voltammetric and biological studies of folate-targeted non-lamellar lipid mesophases
- Jan Biernat
- Ewa Nazaruk
- Marlena Godlewska
2019 Pełny tekst ELECTROCHIMICA ACTA
Folate-targeted lipid nanostructures are promising strategies for the development of biocompatible drug delivery systems. The objective of this study was to evaluate the efficacy of drug delivery to cancer cells by folate-targeted lipid mesophases, cubosomes (CUB) and hexosomes (HEX), loaded with doxorubicin (DOX). Three cancer-derived cell lines (KB, HeLa, T98G) exhibiting different expressional levels of folate receptor protein (FR) were used. DOX-loaded folate-targeted CUB and HEX dispersions were characterized via small angle X-ray scattering and dynamic light scattering to assess their physicochemical properties. DOX release characteristics were evaluated by electrochemical methods and demonstrated structure-dependent release capabilities. A slow release rate was observed for hexosomes, while cubosomes offered more rapid drug transport. Analysis of the release kinetics revealed that the total amount of DOX released from cubosomes is linearly dependent on the square root of time, implying that the release process follows the Higuchi diffusion model. Assessment of drug uptake performed on cancerderived cell lines demonstrated that DOX accumulation in cancer cell depends not only on the release capability of the applied mesophase, but also, on the level of folate receptor protein present in the cancer cells. FR-functionalized CUB and HEX enabled faster drug delivery to cancer cells as a result of receptorligand interactions. In addition, doxorubicin encapsulated into FR-cubosomes demonstrated significantly improved anti-tumor activity promoting the necrosis of tumor cells, while DOX-loaded FA-hexosomes acted via induction of the apoptotic state. Overall, our data indicates that folate-modified formulations are promising drug delivery systems and can be considered as potential therapeutic tools in the targeted therapy of FR-positive tumors.
Voriconazole-Based Salts Are Active against Multidrug-Resistant Human Pathogenic Yeasts
- Emil Szepiński
- Dorota Martynow
- Piotr Szweda
- Maria Milewska
- Sławomir Milewski
2019 Pełny tekst MOLECULES
Voriconazole (VOR) hydrochloride is unequivocally converted into VOR lactates and valinates upon reaction with silver salts of organic acids. This study found that the anticandidal in vitro activity of these compounds was comparable or slightly better than that of VOR. The Candida albicans clinical isolate overexpressing CaCDR1/CaCDR2 genes, highly resistant to VOR, was apparently more susceptible to VOR salts. On the other hand, the susceptibility of another C. albicans clinical isolate (demonstrating multidrug resistance due to the overexpression of CaMDR1) to VOR salts was comparable to that to VOR. Comparative studies on the influence of VOR and its salts on Rhodamine 6G efflux from susceptible and multidrug-resistant C. albicans cells revealed that VOR salts are poorer substrates for the CaCdr1p drug efflux pump than VOR.
W poszukiwaniu wspólnego mianownika dla nauk kosmicznych
- Edmund Wittbrodt
- Zdzisław Brodecki
2019
W artykule zajęto się zagadnieniami znaczenia nauk kosmicznymi dla rozwoju kraju, a przede wszystkim dla kreowania innowacyjnej i konkurencyjnej gospodarki. Omówiono sprawy związane z organizacją i strukturą sektora kosmicznego. Szczególną uwagę poświęcono powiązaniu technologii kosmicznych i satelitarnych z sektorem morskim oraz szeroko pojętym bezpieczeństwem.
Wartość dodana akademickiej biblioteki „mobilnej” w kontekście programu Erasmus+ na przykładzie Biblioteki Politechniki Gdańskiej
- Urszula Szybowska
2019 Pełny tekst
Mobilność wynikająca z założeń programu Erasmus+ w uczelniach i bibliotekach akademickich to wszelkie działania polegające na realizowaniu zagranicznych wyjazdów szkoleniowych w tzw. stażowych miejscach docelowych w krajach-sygnatariuszach programu. Erasmus+ w bibliotekach akademickich umożliwia szeroko pojęte doskonalenie zawodowe, rezultatem którego może być uzyskana wartość dodana uwidoczniona w nabywaniu nowych doświadczeń i kompetencji zawodowych oraz osobistych, które mają realne przełożenie na poprawę standardów oferowanych usług w samej bibliotece i, szerzej, na uczelni. W tekście omówiono stworzenie Library Welcome Center, jako przykładu wartości dodanej zainspirowanej doświadczeniami zdobytymi podczas udziału Biblioteki Politechniki Gdańskiej w programie Erasmus+ w Biblioteca de la Universidad Loyola Andalucía (Kordoba, Sewilla) w roku 2017.
Water Footprint Assessment of Selected Polymers, Polymer Blends, Composites, and Biocomposites for Industrial Application
- Jerzy Korol
- Aleksander Hejna
- Dorota Burchart-Korol
- Błażej Chmielnicki
- Klaudiusz Wypiór
2019 Pełny tekst Polymers
This paper presents a water footprint assessment of polymers, polymer blends, composites, and biocomposites based on a standardized EUR-pallet case study. The water footprint analysis is based on life cycle assessment (LCA). The study investigates six variants of EUR-pallet production depending on the materials used. The system boundary included the production of each material and the injection molding to obtain a standardized EUR-pallet of complex properties. This paper shows the results of a water footprint of six composition variants of analyzed EUR-pallet, produced from biocomposites and composites based on polypropylene, poly(lactic acid), cotton fibers, jute fibers, kenaf fibers, and glass fibers. Additionally, a water footprint of applied raw materials was evaluated. The highest water footprint was observed for cotton fibers as a reinforcement of the analyzed biocomposites and composites. The water footprint of cotton fibers is caused by the irrigation of cotton crops. The results demonstrate that the standard EUR-pallet produced from polypropylene with glass fibers as reinforcement can contribute to the lowest water footprint.
Water uptake analysis of acceptor-doped lanthanum orthoniobates
- Aleksandra Dorota Mielewczyk-Gryń
- Sebastian Lech Wachowski
- Marta Prześniak-Welenc
- Kacper Dzierzgowski
- Anna Regoutz
- David J. Payne
- Maria Gazda
2019 Pełny tekst JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
In this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor doping for the investigated system has been found, and the energetics of the water uptake relation are discussed.
Wave Frequency Effects on Damage Imaging in Adhesive Joints Using Lamb Waves and RMS
- Erwin Wojtczak
- Magdalena Rucka
2019 Pełny tekst Materials
Structural adhesive joints have numerous applications in many fields of industry. The gradual deterioration of adhesive material over time causes a possibility of unexpected failure and the need for non-destructive testing of existing joints. The Lamb wave propagation method is one of the most promising techniques for the damage identification of such connections. The aim of this study was experimental and numerical research on the effects of the wave frequency on damage identification in a single-lap adhesive joint of steel plates. The ultrasonic waves were excited at one point of an analyzed specimen and then measured in a certain area of the joint. The recorded wave velocity signals were processed by the way of a root mean square (RMS) calculation, giving the actual position and geometry of defects. In addition to the visual assessment of damage maps, a statistical analysis was conducted. The influence of an excitation frequency value on the obtained visualizations was considered experimentally and numerically in the wide range for a single defect. Supplementary finite element method (FEM) calculations were performed for three additional damage variants. The results revealed some limitations of the proposed method. The main conclusion was that the effectiveness of measurements strongly depends on the chosen wave frequency value.
Wave transmission across surface interfaces in lattice structures
- Basant Sharma
- Victor Eremeev
2019 Pełny tekst INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
Within the lattice dynamics formulation, we present an exact solution for anti-plane surface waves in a square lattice strip with a surface row of material particles of two types separated by a linear interface. The considered problem is a discrete analog of an elastic half-space with surface stresses modelled through the simplified Gurtin–Murdoch model, where we have an interfacial line separating areas with different surface elastic properties. The main attention is paid to the transmittance and the reflectance of a wave across the interface. The presented results shed a light on the influence on surface waves of surface inhomogeneity in surface elastic properties such as grain and subgrain boundaries.
Waves Along Fractal Coastlines: From Fractal Arithmetic to Wave Equations
- Marek Czachor
2019 Pełny tekst ACTA PHYSICA POLONICA B
Beginning with addition and multiplication intrinsic to a Koch-type curve, we formulate and solve wave equation describing wave propagation along a fractal coastline. As opposed to examples known from the literature, we do not replace the fractal by the continuum in which it is embedded. This seems to be the first example of a truly intrinsic description of wave propagation along a fractal curve. The theory is relativistically covariant under an appropriately defined Lorentz group.
Weak Stability of Centred Quadratic Stochastic Operators
- Krzysztof Bartoszek
- Joachim Domsta
- Małgorzata Pułka
2019 Pełny tekst Bulletin of the Malaysian Mathematical Sciences Society
We consider the weak convergence of iterates of so-called centred quadratic stochastic operators. These iterations allow us to study the discrete time evolution of probability distributions of vector-valued traits in populations of inbreeding or hermaphroditic species, whenever the offspring’s trait is equal to an additively perturbed arithmetic mean of the parents’ traits. It is shown that for the existence of a weak limit, it is sufficient that the distributions of the trait and the perturbation have a finite variance or have tails controlled by a suitable power function. In particular, probability distributions from the domain of attraction of stable distributions have found an application, although in general the limit is not stable.