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Gdańsk University of Technology

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Publications from the year 2020

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  • Architektura pomników poświęconych ofiarom ataków terrorystycznych jako kontynuacja realizacji komemoratywnych kształtowanych w postpamięci
    • Agnieszka Gębczyńska-Janowicz
    • Anna Awtuch
    2020 Full text Politeja. Pismo Wydziału Studiów Międzynarodowych i Politycznych Uniwersytetu Jagiellońskiego

    architecture of Memorials Dedicated to the Victims of terrorist attacks as a continuation of commemorative Structures created within Post-memory Having the rich art of commemorating events of the Second World War as a key reference, this article will try to show how contemporary architectural interven- tions in public space make attempts to respond to the social need of dealing with traumatic events and formulating a new attitude towards threatened places. The point of reference for our reflections will be the events affecting contemporary city in the 21th century associated with terrorist attacks. In order to determine types of architectural narratives about traumatic events developed in urban space, some memorial places in Europe and the USA will be analysed (e.g. Atocha station in Madrid, 9/11 Memorial in New York, Oklahoma City Bombing Memorial). Referring to examples of memorials and monuments, we will look at contempo- rary tendencies in designing commemorative architecture and how architecture reflects and supports the social and individual process of trauma recovery.

  • Artificial Thermal Ageing of Polyester Reinforced and Polyvinyl Chloride Coated Technical Fabric
    • Paweł Kłosowski
    • Krzysztof Żerdzicki
    • Krzysztof Woźnica
    2020 Full text Jove-Journal of Visualized Experiments

    Architectural fabric AF9032 has been subjected to artificial thermal ageing to determine changes of the material parameters of the fabric. The proposed method is based on the accelerated ageing approach proposed by Arrhenius. 300 mm x 50 mm samples were cut in the warp and fill directions and placed in a thermal chamber at 80 °C for up to 12 weeks or at 90 °C for up to 6 weeks. Then after one week of conditioning at ambient temperature, the samples were uniaxially tensioned at a constant strain rate. Experimentally, the parameters were determined for the non-linear elastic (linear piecewise) and viscoplastic (Bodner–Partom) models. Changes in these parameters were studied with respect to the ageing temperature and ageing period. In both cases, the linear approximation function was successfully applied using the simplified methodology of Arrhenius. A correlation was obtained for the fill direction between experimental results and the results from the Arrhenius approach. For the warp direction, the extrapolation results exhibited some differences. Increasing and decreasing tendencies have been observed at both temperatures. The Arrhenius law was confirmed by the experimental results only for the fill direction. The proposed method makes it possible to predict real fabric behavior during long term exploitation, which is a critical issue in the design process

  • Assessing Industry 4.0 Features Using SWOT Analysis
    • Ahmad Reshad Bakhtari
    • Mohammad Waris
    • Bisma Mannan
    • Cesar Sanin
    • Edward Szczerbicki
    2020 Full text Communications in Computer and Information Science

    This paper assesses some features of industry 4.0 by using SWOT analysis that affects the adoption and implementation of industry 4.0. The paper identifies the strengths, weaknesses, opportunities, and threats related to industry 4.0. By the consideration of these four groups of factors, the industrial practitioners can understand how to implement industry 4.0. Moreover, industrial practitioners can use the strengths/opportunities offered by industry 4.0 to take strategic decisions to decrease the effect of the threats/weaknesses that come along with industry 4.0.

  • Assessment of Citizens’ Actions against Light Pollution with Guidelines for Future Initiatives
    • Karolina Zielińska-Dąbkowska
    • Kyra Xavia
    • Katarzyna Bobkowska
    2020 Full text Sustainability

    Due to the wide reach of media reports about scientific research and technological tools such as the world wide web (WWW), the Internet, and web browsers, citizens today have access to factual information about the negative impact of artificial light at night (ALAN) on their dark skies, and their health and well-being. This means they can now make educated decisions and take the necessary steps to help protect themselves and their communities from disruptive light pollution. Whilst this action is positive and welcomed, unfortunately, according to collected data, not all such initiatives have been successful. Although our understanding of this groundswell movement is deepening, further studies are required to complete a worldwide picture of the current situation. This paper therefore investigates the various actions taken by citizens, as well as the challenges, methods, and tools involved, regarding good practices initiated by grass roots activism on how to reduce existing and potential light pollution. The results of a comparative analysis of 262 international case studies (lawsuits and online petitions) reveal that, since the 1990s, there has been an increase in the number of legal cases related to light pollution due to the rise in public awareness, the availability of scientific knowledge via the Internet, and the ability to take accurate lighting measurements and perform lighting simulations. Also, in the last decade a new tool for digital participation in the form of online petitions has established a new movement of citizen action to mitigate the effects of light pollution. Based on this information, a seven-step framework involving recommendations for citizen action has been developed. It is expected that this new knowledge will benefit those citizens planning future efforts involving the development, implementation, and monitoring processes of outdoor lighting. Additionally, it might support the evolution of planning and policy approaches that are sustainable and necessary to improve the application and installation of ecologically/biologically responsible illumination for towns, cities, and natural habitats.

  • Assessment of Electronic Sensing Techniques for the Rapid Identification of Alveolar Echinococcosis through Exhaled Breath Analysis
    • Andrzej Kwiatkowski
    • Tomasz Chludziński
    • Tarik Saidi
    • Tesfalem Welearegay
    • Aylen Jaimes-Mogollón
    • Nezha El Bari
    • Sebastian Borys
    • Benachir Bouchikhi
    • Janusz Smulko
    • Radu Ionescu
    2020 Full text SENSORS

    Here we present a proof-of-concept study showing the potential of a chemical gas sensors system to identify the patients with alveolar echinococcosis disease through exhaled breath analysis. The sensors system employed comprised an array of three commercial gas sensors and a custom gas sensor based on WO3 nanowires doped with gold nanoparticles, optimized for the measurement of common breath volatile organic compounds. The measurement setup was designed for the concomitant measurement of both sensors DC resistance and AC fluctuations during breath samples exposure. Discriminant Function Analysis classification models were built with features extracted from sensors responses, and the discrimination of alveolar echinococcosis was estimated through bootstrap validation. The commercial sensor that detects gases such as alkane derivatives and ethanol, associated with lipid peroxidation and intestinal gut flora, provided the best classification (63.4% success rate, 66.3% sensitivity and 54.6% specificity) when sensors’ responses were individually analyzed, while the model built with the AC features extracted from the responses of the cross-reactive sensors array yielded 90.2% classification success rate, 93.6% sensitivity and 79.4% specificity. This result paves the way for the development of a noninvasive, easy to use, fast and inexpensive diagnostic test for alveolar echinococcosis diagnosis at an early stage, when curative treatment can be applied to the patients

  • ASSESSMENT OF FINANCIAL SECURITY OF AN ENTERPRISE ON THE BASIS OF BEHAVIORAL ECONOMICS
    • Oleksandr Melnychenko
    2020 Full text BULLETIN OF THE CHERKASY BOHDAN KHMELNYTSKY NATIONAL UNIVERSITY. ECONOMIC SCIENCES

    The article substantiates that the level of company’s financial security depends not so much on the indicators of its activity, but on its perception of decision-makers and other stakeholders. At the same time, this perception is formed due to the continuous participation of the stakeholder in operations, constant monitoring of financial indicators, the study of current approaches to enterprise management, changes in the environment, market conditions, etc. The role of economic analysis in assessing company’s financial security as a state is not in its complex study, but in the presented economic indicators, the processing of quantitative data on the company’s financial security. Instead, to speak of a comprehensive and thorough study of the level of financial security on the basis of economic analysis only would be incorrect and unreliable. Indices, indicators that are analyzed on the basis of financial or management reporting provide only a cursory view of the problem or even distort the overall picture, as they are taken at a particular point in time. For example, liquidity indicators change in certain groups of businesses and the country's economic or political environment can transform a liquid company with a solid stock of liquidity into absolutely illiquid in a few moments. However, considering the previous data of economic analysis without bearing in mind other aspects, it is possible to make fatal decisions for the company. Although, of course, such a scenario is impossible, since behind each enterprise there are people, whose decisions and experience depend on its further development, and practice shows that such people are not oriented solely to economic analysis data without context, to assess the situation in the economy of the country or the world in general. Their experience and perception of financial security are essencial in decision making. Thus, the paper argues that the method of expert assessment of company’s financial security is the most objective one, which, however, has disadvantages associated with cognitive limitations of people

  • Assessment of the Effective Variants Leading to Higher Efficiency for the Geothermal Doublet, Using Numerical Analysis‒Case Study from Poland (Szczecin Trough)
    • Anna Wachowicz-Pyzik
    • Anna Sowiżdżał
    • Leszek Pająk
    • Paweł Ziółkowski
    • Janusz Badur
    2020 Full text ENERGIES

    Numerical models of geothermal doublet allows us to reduce the high risk associated with the selection of the most eective location of a production well. Furthermore, modeling is a suitable tool to verify possible changes in operational geothermal parameters, which guarantees liveliness of the system. An appropriate selection of software as well as the methodology used to generate numerical models significantly aects the quality of the obtained results. In this paper, the authors discuss the influence of such parameters as grid density and distance between wells on the eciency of geothermal heating plant. The last stage of the analysis was connected with estimation of geothermal power potential for a hypothetical geothermal doublet. Numerical simulations were carried out using the TOUGH2 code, which applies the finite-dierence method. The research was conducted in the Szczecin Trough area (NW Poland), based on archival data from Choszczno IG-1 well. The results demonstrated that in the studied case of the Choszczno region, the changes in the distance of boreholes can have a visible influence on obtained results; however the grid density of the numerical model did not achieve a significant impact on it. The results show the significant importance of numerical modeling aimed at increasing the eciency of a potential geothermal heating plant.

  • Assessment of the Speed Management Impact on Road Traffic Safety on the Sections of Motorways and Expressways Using Simulation Methods
    • Jacek Oskarbski
    • Tomasz Kamiński
    • Kyandoghere Kyamakya,
    • Jean Chamberlain Chedjou,
    • Karol Żarski
    • Małgorzata Pędzierska
    2020 Full text SENSORS

    Methods used to evaluate the impact of Intelligent Transport System (ITS) services on road safety are usually based on expert assessments or statistical studies. However, commonly used methods are challenging to apply in the planning process of ITS services. This paper presents the methodology of research using surrogate safety measures calculated and calibrated with the use of simulation techniques and a driving simulator. This approach supports the choice of the type of ITS services that are beneficial for traffic efficiency and road safety. This paper presents results of research on the influence of selected scenarios of variable speed limits on the eciency and safety of traffic on the sections of motorways and expressways in various traffic conditions. The driving simulator was used to estimate the eciency of lane-keeping by the driver. The simulation traffic models were calibrated using driving simulator data and roadside sensor data. The traffic models made it possible to determine surrogate safety measures (number of conflicts and their severity) in selected scenarios of using ITS services. The presented studies confirmed the positive impact of Variable Speed Limits (VSLs) on the level of road safety and traffic efficiency. This paper also presents recommendations and plans for further research in this area.

  • Assessment of Trajectories of Non-bankrupt and Bankrupt Enterprises
    • Tomasz Korol
    2020 Full text European Research Studies Journal

    The aim of this study is to show how long-term trajectories of enterprises can be used to increase the forecasting horizon of bankruptcy prediction models. The author used seven popular forecasting models (two from Europe, two from Asia, two from North America and one from Latin America). These models (five multivariate discriminant analysis models and two logit models) were used to develop 17-year trajectories separately for non-bankrupt enterprises and those at risk of financial failure. Based on a sample of 200 enterprises, the author evaluated the differences between non-bankrupt and bankrupt firms in development during 17 years of activity. The long-term usability of the models was demonstrated. To date, these models have been used only to forecast bankruptcy risk in the short term (1–3 years’ prediction horizon). This paper demonstrates that these models can also serve to evaluate long-term growth and to identify the first symptoms of future bankruptcy risk many years before it actually occurs. It was proven and specified that long-term developmental differences exist between non-threatened and future insolvent companies. These studies proved that the process of going bankrupt is very long, perhaps even longer than the literature has previously demonstrated. This study is one of the first attempts in the literature globally to assess such long-term enterprise trajectories. Additionally by implementing a dynamic approach to the financial ratios in the risk-forecasting model let visualize the changes occurring in the company.

  • Assessment of Wide-Sense Stationarity of an Underwater Acoustic Channel Based on a Pseudo-Random Binary Sequence Probe Signal
    • Iwona Kochańska
    2020 Full text Applied Sciences-Basel

    The performances of Underwater Acoustic Communication (UAC) systems are strongly related to the specific propagation conditions of the underwater channel. Designing the physical layer of a reliable data transmission system requires a knowledge of channel characteristics in terms of the specific parameters of the stochastic model. The Wide-Sense Stationary Uncorrelated Scattering (WSSUS) assumption simplifies the stochastic description of the channel, and thus the estimation of its transmission parameters. However, shallow underwater channels may not meet the WSSUS assumption. This paper proposes a method for testing the Wide-Sense Stationary (WSS) part of the WSSUS feature of a UAC channel on the basis of the complex envelope of a received probe Pseudo-Random Binary Sequence (PRBS) signal. Two correlation coefficients are calculated that can be interpreted, together, as a measure that determines whether the channel is WSS or not. A similar wide-sense stationarity assessment can be performed on the basis of the Time-Varying Impulse Response (TVIR) of a UAC channel. However, the method proposed in this paper requires fewer computational operations in the receiver of a UAC system. PRBS signal transmission tests were conducted in the UAC channel simulator and in real conditions during an inland water experiment. The correlation coefficient values obtained using the method based on the envelope of a probe signal and the method of analysing the TVIR estimates are compared. The results are similar, and thus, it is possible to assess if the UAC channel can be modelled as a WSS stochastic process without the need for TVIR estimation.

  • Association of Genes Related to Oxidative Stress with the Extent of Coronary Atherosclerosis
    • Milena Racis
    • Anna Stanisławska-Sachadyn
    • Wojciech Sobiczewski
    • Marcin Wirtwein
    • Michał Krzemiński
    • Natalia Krawczyńska
    • Janusz Limon
    • Andrzej Rynkiewicz
    • Marcin Gruchała
    2020 Full text Life

    Oxidative stress is believed to play a critical role in atherosclerosis initiation and progression. In line with this, in a group of 1099 subjects, we determined eight single nucleotide polymorphisms (SNPs) related to oxidative stress (PON1 c.575A>G, MPO c.463G>A, SOD2 c.47T>C, GCLM c.590C>T, NOS3 c.894G>T, NOS3 c.786T>C, CYBA c.214C>T, and CYBA c.932A>G) and assessed the extent of atherosclerosis in coronary arteries based on Gensini score. An increased risk of having a Gensini score in the higher half of the distribution was observed for the PON1 c.575G allele (odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.004–1.617, p = 0.046). Next, the genetic risk score (GRS) for the additive eect of the total number of pro-oxidative alleles was assessed. We noted an increase in the risk of having a Gensini score above the median with the maximum number of risk alleles (OR = 2.47, 95% CI: 1.19–5.23, p = 0.014). A univariate Spearman’s test revealed significant correlation between the total number of pro-oxidant alleles (GRS) and the Gensini score ( = 0.068, p = 0.03). In conclusion, the PON1 c.575A>G variant and the high number of risk alleles (GRS) were independent risk factors for a high Gensini score. We suggest, however, that GRS might occur as a more valuable component in adding a predictive value to the genetic background of atherosclerosis.

  • Attempt to a Video-Transmission Capability in MV Mine Cable Network Using BPL-PLC Technology
    • Grzegorz Debita
    • Przemysław Falkowski-Gilski
    • Marcin Habrych
    • Bogdan Miedziński
    • Grzegorz Wiśniewski
    • Przemysław Jedlikowski
    • Bartosz Polnik
    2020

    This article presents and discusses the attempt to transmit video content using the BPL-PLC (Broadband over Power Line - Power Line Communication) technology. It includes simulation results of a specially developed digital transmitter and receiver, dedicated to a given predefined 6 kV mining power cable. The effect of two different transmission modes (2-7 MHz and 3-7.5 MHz) and two types of coupling (capacitive-inductive and induction-inductive), on the quality of bi-directional transmission, was also examined. The quality assessment of transmitted content, including both QoS (Quality of Service) and QoE (Quality of Experience) approaches, was evaluated on a set of samples processed in different resolution, namely: 480x270, 768x432, and 1280x720. Based on this, conclusions have been formulated, regarding the expected efficiency, as well as guidelines for further video transmission tests, including real-time mining conditions.

  • Atypical application of the parametric method for track infrastructure inventory
    • Krzysztof Czaplewski
    • Cezary Specht
    • Władysław Koc
    • Andrzej Wilk
    • Krzysztof Karwowski
    • Paweł Dąbrowski
    • Mariusz Specht
    • Piotr Chrostowski
    • Jacek Szmagliński
    2020 Full text Zeszyty Naukowe Akademii Morskiej w Szczecinie

    For many years, satellite systems have seen widespread use in a variety of technical applications, as well as in operations related to setting-out and the exploitation of track infrastructure. Their main applications include an inventory of the trackage course and detecting changes in its position. In both of these tasks, the most important element that determines the quality of an analyses is the high accuracy of the determinations being carried out. Satellite surveying techniques are not always sufficiently accurate, and in such cases, it is necessary to employ other land surveying methods to process surveying data. This article presents the authors’ considerations with regards to the possibility of applying one of the most common land surveying adjustment methods, the parametric method, to operations related to an inventory of tram infrastructure in Gdańsk. The results are based on surveys carried out during a surveying campaign in the autumn of 2018. The considerations presented in the article concern a small part of the research conducted under project No. POIR.04.01.01-00-0017/17 entitled “Development of an innovative method for determining the precise trajectory of a railborne vehicle” which is being implemented by a consortium of Gdansk University of Technology and Gdynia Maritime University.

  • Audio Feature Analysis for Precise Vocalic Segments Classification in English
    • Szymon Zaporowski
    • Andrzej Czyżewski
    2020

    An approach to identifying the most meaningful Mel-Frequency Cepstral Coefficients representing selected allophones and vocalic segments for their classification is presented in the paper. For this purpose, experiments were carried out using algorithms such as Principal Component Analysis, Feature Importance, and Recursive Parameter Elimination. The data used were recordings made within the ALOFON corpus containing audio signal recorded employing 7 speakers who spoke English at the native or near-native speaker level withing a Standard Southern British English variety accent. The recordings were analyzed by specialists from the field of phonology in order to extract vocalic segments and selected allophones. Then parameterization was made using Mel Frequency Cepstral Coefficients, Delta MFCC, and Delta Delta MFCC. In the next stage, feature vectors were passed to the input of individual algorithms utilized to reduce the size of the vector by previously mentioned algorithms. The vectors prepared in this way have been used for classifying allophones and vocalic segments employing simple Artificial Neural Network (ANN) and Support Vector Machine (SVM). The classification results using both classifiers and methods applied for reducing the number of parameters were presented. The results of the reduction are also shown explicitly, by indicating parameters proven to be significant and those rejected by particular algorithms. Factors influencing the obtained results were discussed. Difficulties associated with obtaining the data set, its labeling, and research on allophones were also analyzed.

  • AutoCAD: Examination of Factors Influencing User Adoption
    • Anna Baj-Rogowska
    2020 Full text Engineering Management in Production and Services

    The primary purpose of the research is to examine and validate determinants of user intention to use AutoCAD software, utilising the constructs from prior studies in a more integrated model. The paper proposes a revised Technology Acceptance Model (TAM) for measuring the adoption of AutoCAD. In the study, a latent construct PPA (perceived physical accessibility) was added to the proposed research model as a new determinant of AutoCAD adoption. An online survey of AutoCAD users was conducted to collect data. This data was empirically used to test the proposed research model. The Structural Equation Modelling (SEM) technique was used to evaluate the causal model, and the confirmatory factor analysis was performed to examine the reliability and validity of the measurement model. The study results show that user behavioural intention to use AutoCAD is significantly affected by three determinants: perceived usefulness, perceived ease of use and perceived physical accessibility of the software. This finding contributes to an expanded understanding of the factors that promote acceptance of AutoCAD software. Moreover, the main contribution of this study is to verify the impact of the added PPA variable on the behavioural intention to use and the actual use of AutoCAD, and also to create measurement scales for this new latent variable in TAM.

  • Autogenous Fiber Laser Welding of 316L Austenitic and 2304 Lean Duplex Stainless Steels
    • Michał Landowski
    • Aleksandra Świerczyńska
    • Grzegorz Rogalski
    • Dariusz Fydrych
    2020 Full text Materials

    This study presents results of experimental tests on quality of dissimilar welded joints between 316L austenitic and 2304 lean duplex stainless steels, welded without ceramic backing. Fiber laser welded butt joints at a thickness of 8 mm were subjected to non‐destructive testing (visual and penetrant), destructive testing (static tensile test, bending test, and microhardness measurements) and structure observations (macro‐ and microscopic examinations, SEM, element distribution characteristics, and ferrite content measurements). Non‐destructive tests and metallographic examinations showed that the welded joints meet the acceptance criteria for B level in accordance with EN ISO 13919–1 standard. Also the results of the destructive tests confirmed the high quality of the joints: specimens were fractured in base material with lower strength—316L austenitic stainless steel and a 180° bending angle was obtained confirming the high plasticity of the joints. Microscopic examination, SEM and EDS analysis showed the distribution of alloying elements in joints. The microhardness of the autogenous weld metal was higher by about 20 HV0.2 than that of the lean duplex steel. Ferrite content in the root was about 37% higher than in the face of the weld. The Schaeffler phase diagram was used to predict the phase composition of the welded joints and sufficient compliance with the magnetic method was found. The presented procedure can be used for welding of 316L–2304 stainless steels dissimilar welded joints of 8 mm thickness without ceramic backing.

  • Automated Classifier Development Process for Recognizing Book Pages from Video Frames
    • Adam Brzeski
    • Jan Cychnerski
    • Karol Draszawka
    • Krystyna Dziubich
    • Tomasz Dziubich
    • Waldemar Korłub
    • Paweł Rościszewski
    2020 Communications in Computer and Information Science

    One of the latest developments made by publishing companies is introducing mixed and augmented reality to their printed media (e.g. to produce augmented books). An important computer vision problem that they are facing is classification of book pages from video frames. The problem is non-trivial, especially considering that typical training data is limited to only one digital original per book page, while the trained classifier should be suitable for real-time utilization on mobile devices, where camera can be exposed to highly diverse conditions and computing resources are limited. In this paper we address this problem by proposing an automated classifier development process that allows training classification models that run real-time, with high usability, on low-end mobile devices and achieve average accuracy of 88.95% on our in-house developed test set consisting of over 20 000 frames from real videos of 5 books for children. At the same time, deployment tests reveal that the classifier development process time is reduced approximately 16-fold.

  • Automatic Marking of Allophone Boundaries in Isolated English spoken Words
    • Janusz Rafałko
    • Andrzej Czyżewski
    2020 Full text

    The work presents a method that allows delimiting the borders of allophones in isolated English words. The described method is based on the DTW algorithm combining two signals, a reference signal and an analyzed one. As the reference signal, recordings from the MODALITY database were used, from which the words were extracted. This database was also used for tests, which were described. Test results show that the automatic determination of the allophone limits in English words is possible with good accuracy. Tests have been carried out to determine the error of particular allophones borders marking and to find out the cost of matching the given allophone to the reference one. Based on this cost, a coefficient has been introduced that allows for determining in percentage how much the automatically marked allophone is similar to the reference one. This coefficient can be used for an assessment of the correctness of the pronunciation of the allophone. The possibilities of further research and development of this method were also analyzed.

  • Automatic Threat Detection for Historic Buildings in Dark Places Based on the Modified OptD Method
    • Wioleta Błaszczak-bąk
    • Czesław Suchocki
    • Joanna Janicka
    • Andrzej Dumalski
    • Robert Duchnowski
    • Anna Sobieraj-Żłobińska
    2020 Full text ISPRS International Journal of Geo-Information

    Historic buildings, due to their architectural, cultural, and historical value, are the subject of preservation and conservatory works. Such operations are preceded by an inventory of the object. One of the tools that can be applied for such purposes is Light Detection and Ranging (LiDAR). This technology provides information about the position, reflection, and intensity values of individual points; thus, it allows for the creation of a realistic visualization of the entire scanned object. Due to the fact that LiDAR allows one to ʹseeʹ and extract information about the structure of an object without the need for external lighting or daylight, it can be a reliable and very convenient tool for data analysis for improving safety and avoiding disasters. The main goal of this paper is to present an approach of automatic wall defect detection in unlit sites by means of a modified Optimum Dataset (OptD) method. In this study, the results of Terrestrial Laser Scanning (TLS) measurements conducted in two historic buildings in rooms without daylight are presented. One location was in the basement of the ruins of a medieval tower located in Dobre Miasto, Poland, and the second was in the basement of a century‐old building located at the University of Warmia and Mazury in Olsztyn, Poland. The measurements were performed by means of a Leica C‐10 scanner. The acquired dataset of x, y, z, and intensity was processed by the OptD method. The OptD operates in such a way that within the area of interest where surfaces are imperfect (e.g., due to cracks and cavities), more points are preserved, while at homogeneous surfaces (areas of low interest), more points are removed (redundant information). The OptD algorithm was additionally modified by introducing options to detect and segment defects on a scale from 0 to 3 (0—harmless, 1—to the inventory, 2—requiring repair, 3—dangerous). The survey results obtained proved the high effectiveness of the modified OptD method in the detection and segmentation of the wall defects. The values of area of changes were calculated. The obtained information about the size of the change can be used to estimate the costs of repair, renovation, and reconstruction.

  • Autonomous Ship Utility Model Parameter Estimation Utilising Extended Kalman Filter
    • Anna Witkowska
    • Krzysztof Armiński
    • Tomasz Zubowicz
    • Filip Ossowski
    • Roman Smierzchalski
    2020

    In this paper, a problem of autonomous ship utility model identification for control purposes is considered. In particular, the problem is formulated in terms of model parameter estimation (one-step-ahead prediction). This is a complex task due to lack of measurements of the parameter values, their time-variability and structural uncertainty introduced by the available models. In this work, authors consider and compare two utility models based on often utilised ship model structures with time-varying parameters identified recursively using the extended Kalman lter (EKF). The validation results have been obtained using simulation experiments in which the required information for the parameter estimation task had been generated using a cognitive model of B-481 ship. The results indicate the benefits and drawbacks, In terms of estimation accuracy and computational complexity, of using each of the investigated utility model structures.