2019 - Repozytorium publikacji - Politechnika Gdańska

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Uzyskanie standardu pasywnego
- Mateusz Pankanin
- Marcin Szczepański
2019 Pełny tekst Builder
Celem artykułu jest ocena budynku mieszkalnego w zabudowie bliźniaczej w świetle obowiązujących przepisów dotyczących energooszczędności oraz analiza czasów i kosztów jego wykonania w dwóch wariantach klasy energetycznej. W ramach analizy wyliczono bilans strat oraz zysków ciepła, na podstawie którego utworzono wskaźniki charakterystyczne. Następnie zaproponowano rozwiązania pozwalające obniżyć te wskaźniki do poziomu dopuszczalnych według obowiązujących i przyszłych przepisów dla budynków jednorodzinnych pasywnych oraz porównano koszty i czasy realizacji budynku tradycyjnego ze zmodernizowanym w kierunku klasy budynku pasywnego.
Validating data acquired with experimental multimodal biometric system installed in bank branches
- Piotr Szczuko
- Andrzej Czyżewski
- Piotr Hoffmann
- Piotr Bratoszewski
- Michał Lech
2019 Pełny tekst JOURNAL OF INTELLIGENT INFORMATION SYSTEMS
An experimental system was engineered and implemented in 100 copies inside a real banking environment comprising: dynamic handwritten signature verification, face recognition, bank client voice recognition and hand vein distribution verification. The main purpose of the presented research was to analyze questionnaire responses reflecting user opinions on: comfort, ergonomics, intuitiveness and other aspects of the biometric enrollment process. The analytical studies and experimental work conducted in the course of this work will lead towards methodologies and solutions of the multimodal biometric technology, which is planned for further development. Before this stage is achieved a study on the data usefulness acquired from a variety of biometric sensors and from survey questionnaires filled in by banking tellers and clients was done. The decision-related sets were approximated by the Rough Set method offering efficient algorithms and tools for finding hidden patterns in data. Prediction of evaluated biometric data quality, based on enrollment samples and on user subjective opinions was made employing the developed method. After an introduction to the principles of applied biometric identity verification methods, the knowledge modelling approach is presented together with achieved results and conclusions.
Validation of a virtual test environment for C2X communication under radio jamming conditions
- Michał Tarkowski
- Mateusz Rzymowski
- Łukasz Kulas
- Krzysztof Nyka
- Marcin Borawski
- Przemysław Kwapisiewicz
- Wojciech Piechowski
- Gerald Temme
- Saifullah Khan
- Danny Behnecke
- Mohamed Mahmod
2019 Pełny tekst
In this paper, we propose a novel car-2-x communication security testing methodology in the physical layer of wireless systems. The approach is dedicated to automated testing of autonomous vehicles and it is essential for such complex systems operation, especially with regard to safety and security issues. It is based on scenario-driven testing in virtual and real test environments created from collected or simulated data. The presented approach is dedicated for reducing the time and costs of testing and generates a number of potential situations to examine the autonomous system behavior with regard to the wireless communication security. The conducted test results compare some exemplary scenarios, which involve 802.11p C2X communication in presence of intentional interferences, which are realized in different configurations: SiL, HiL and in-field measurements.
Valuation of architectural heritage by multicultural student groups
- Jakub Szczepański
2019 Pełny tekst Global Journal of Engineering Education
In this article, the author addresses the education of architecture students in the field of architectural history and the determination of the value of architectural objects. Important changes at present are underway concerning this. Both the role of architectural history in architectural education and content in architectural history curricula is changing. The need for re-evaluation and reconstruction of the role of architectural history in education arises from several reasons. Educational needs are also changing because of globalisation. The field of monument protection is widening, the number of objects that are subject to protection increases rapidly. Ecological needs require greater care for the existing building substance. At the end of the article, the solutions implemented at Gdańsk University of Technology, Gdańsk, Poland, are presented: these are aimed at solving the problem of teaching students how to evaluate architectural heritage.
Vapor correction of FTIR spectra – A simple automatic least squares approach
- Piotr Bruździak
2019 Pełny tekst SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
FTIR spectroscopy is one of the best techniques to study intermolecular interactions. However, such an application requires high quality spectra with as little noise as possible, which are often difficult to obtain. One of the main sources of unwanted interference is water vapor. Here a robust method is proposed for automatic, fast and reliable vapor correction of FTIR spectra. The presented least squares approach of vapor subtraction using many vapor spectra and a special residual function provides a much better correction. It does not rely on the researcher's experience, no coefficients are arbitrarily chosen or tweaked, thus such results are more trustworthy and accurate.
Variable length sliding models for banking clients face biometry
- Piotr Szczuko
- Andrzej Czyżewski
- Maciej Szczodrak
2019 Pełny tekst MULTIMEDIA TOOLS AND APPLICATIONS
An experiment was organized in 100 bank branches to acquire biometric samples from nearly 5000 clients including face images. A procedure for creating face verification models based on continuously expanding database of biometric samples is proposed, implemented, and tested. The presented model applies to circumstances where it is possible to collect and to take into account new biometric samples after each positive verification of the user. Thus the model can evolve in time, and it can follow changes of user face characteristics, e.g. changes in complexion, variable amount of facial hair, arriving wrinkles, cheeks chubbiness appearance, etc., introduced as effects of changing lifestyle, sunbathing, gaining weight, aging or other processes. The variable length sliding models derived from the gathered experimental data are described in the paper.
Variable-fidelity response feature surrogates for accelerated statistical analysis and yield estimation of compact microwave components
- Sławomir Kozieł
- Adrian Bekasiewicz
2019 Pełny tekst IET Microwaves Antennas & Propagation
Accounting for manufacturing tolerances is an essential part of a reliable microwave design process. Yet, quantification of geometry and/or material parameter uncertainties is challenging at the level of full-wave electromagnetic (EM) simulation models. This is due to inherently high cost of EM analysis and massive simulations necessary to conduct the statistical analysis. Here, a low-cost and accurate yield estimation procedure for compact microwave couplers is proposed. Authors’ technique involves variable-fidelity electromagnetic (EM) simulation models, as well as fast surrogates constructed using a response feature approach. In order to improve the computational efficiency of the analysis, the primary surrogate is obtained from the characteristic points of the low-fidelity model and, subsequently, corrected using a single evaluation of the high-fidelity model. Combination of both methods results in an extremely low cost of yield estimation being just a few high-fidelity EM analyses. For the sake of demonstration, a compact hybrid rat-race coupler operating at 1 GHz is considered. Yield estimation is carried out under several scenarios concerning various probability distributions of the geometry parameter deviations. Reliability of the approach is verified by comparing the results with direct Monte–Carlo analysis and single-fidelity feature-based yield estimation.
Variable-Fidelity Simulation Models and Sparse Gradient Updates for Cost-Efficient Optimization of Compact Antenna Input Characteristics
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2019 Pełny tekst SENSORS
Design of antennas for the Internet of Things (IoT) applications requires taking into account several performance figures, both electrical (e.g., impedance matching) and field (gain, radiation pattern), but also physical constraints, primarily concerning size limitation. Fulfillment of stringent specifications necessitates the development of topologically complex structures described by a large number of geometry parameters that need tuning. Conventional optimization procedures are typically too expensive when the antenna is evaluated using high-fidelity electromagnetic (EM) analysis, otherwise required to ensure accuracy. This paper proposes a novel surrogate-assisted optimization algorithm for computationally efficient design optimization of antenna structures. In the paper, the optimization of antenna input characteristic is presented, specifically, minimization of the antenna reflection coefficient in a given bandwidth. Our methodology involves variable-fidelity EM simulations as well as a dedicated procedure to reduce the cost of estimating the antenna response gradients. The latter is based on monitoring the variations of the antenna response sensitivities along the optimization path. The procedure suppresses the finite-differentiation-based sensitivity updates for variables that exhibit stable gradient behavior. The proposed algorithm is validated using three compact wideband antennas and demonstrated to outperform both the conventional trust region algorithm and the pattern search procedure, as well as surrogate-based procedures while retaining acceptable design quality.
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.