2023 - Repozytorium publikacji - Politechnika Gdańska

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Assessment of Wooden Beams from Historical Buildings Using Ultrasonic Transmission Tomography
- Monika Zielińska
- Magdalena Rucka
2023 Pełny tekst International Journal of Architectural Heritage
The main goal of this study was non-destructive evaluation of wooden elements using ultrasonic waves. The inspection was carried out on wooden beams from a historical object. Elastic wave signals were processed by ultrasonic transmission tomography to obtain imaging of the internal structure of tested elements without disturbing their state and integrity. The focus was on the influence of wood anisotropy on the propagation of ultrasonic waves. A novel method of determining the position of the cross-section pith was proposed. The study presented that the proposed imaging approach was capable to assess the technical condition of historic wooden beams by determining the degree of wood damage and the location of discontinuities, scratches or fibrosis in the tested cross-section.
Assessment, optimisation and working fluid comparison of organic rankine cycle combined with negative CO2 gas power plant system
- Kamil Stasiak
- Paweł Ziółkowski
- Dariusz Mikielewicz
2023 Pełny tekst
This study aims to investigate the application of the Organic Rankine Cycle (ORC) as an alternative to low-pressure expansion in the negative CO2 power plant (nCO2PP). The reason for this study is that a detailed analysis of nCO2PP indicates a certain amount of waste heat present in the exhaust gas from the high-to-intermediate pressure gas turbine. Some of this energy can be used by the application of the expansion in a low-pressure turbine, optionally the application of regenerative water heating, which is further directed to the combustion chamber, and alternatively the combination of the ORC into the main cycle. For the ORC cycle, various configurations are examined, either with or without regenerative water heating and using different working mediums. For the highest cycle efficiency, regenerative heating of high-pressure water is applied, and proper ORC working fluid with optimum saturation point and mass flow is selected. Such modified nCO2PP power plant hybrid systems with ORC are compared to the original concept of nCO2PP with lower pressure expansion. A hybrid system integrating the advantages of nCO2PP and an ORC cycle is a promising solution, and modifications are possible, but the main advantage is that an ORC cycle can be introduced as a component to provide electrical power in the lower temperature range. Three ORC mediums were calculated, namely ethanol, refrigerants R236-ea and R245-fa which yielded net efficiency of the whole power plant of 38.35%, 40.16% and 40.39% respectively, while the original nCO2PP yielded 38.89%.
Asymptomatic Bacteriuria in Kidney Transplant Recipients—A Narrative Review
- Justyna Gołębiewska
- Beata Krawczyk
- Wysocka Magdalena
- Aleksandra Dudziak
- Alicja Dębska-ślizień
2023 Pełny tekst Medicina
Urinary tract infections (UTIs) are the most prevalent complications in kidney transplant (KTx) recipients. The most frequent finding in this group of patients is asymptomatic bacteriuria (ASB). Here, we provide an overview of the available evidence regarding ASB in KTx recipients, including its etiopathology, clinical impact and management. There is a growing body of evidence from clinical trials that screening for and treating ASB is not beneficial in most KTx recipients. However, there are insufficient data to recommend or discourage the use of a “screen-and-treat strategy” for ASB during the first 1–2 months post-transplant or in the case of an indwelling urinary catheter. Despite its frequency, ASB after KTx is still an understudied phenomenon.
Asynchronous Charge Carrier Injection in Perovskite Light-Emitting Transistors
- Maciej Klein
- Krzysztof Blecharz
- Bryan Hao, Wei
- Annalisa Bruno
- Cesare Soci
2023 Pełny tekst Advanced Electronic Materials
Unbalanced mobility and injection of charge carriers in metal-halide perovskite light-emitting devices pose severe limitations to the efficiency and response time of the electroluminescence. Modulation of gate bias in methylammonium lead iodide light-emitting transistors has proven effective in increasing the brightness of light emission up to MHz frequencies. In this work, a new approach is developed to improve charge carrier injection and enhance electroluminescence of perovskite light-emitting transistors by independent control of drain–source and gate–source bias voltages to compensate for space-charge effects. Optimization of bias pulse synchronization induces a fourfold enhancement of the emission intensity. Interestingly, the optimal phase delay between biasing pulses depends on modulation frequency due to the capacitive nature of the devices, which is well captured by numerical simulations of an equivalent electrical circuit. These results provide new insights into the electroluminescence dynamics of AC-driven perovskite light-emitting transistors and demonstrate an effective strategy to optimize device performance through independent control of the amplitude, frequency, and phase of the biasing pulses.
Asynchronous Method of Simultaneous Object Position and Orientation Estimation with Two Transmitters
- Jacek Stefański
- Jarosław Sadowski
2023 Pełny tekst Navigation-Journal of the Institute of Navigation
This paper proposes an object location method for all types of applications, including the Internet of Things. The proposed method enables estimations of the position and orientation of an object on a plane or in space, especially during motion, by means of location signals transmitted simultaneously from two transmitters placed on the object at a known distance from each other. A mathematical analysis of the proposed method and Newton’s algorithm for solving the system of nonlinear positional equations is presented. Next, an analysis of a position-dilution-of-precision parameter for the proposed method and a Cramer–Rao lower bound, limiting the accuracy of the method, is presented. Finally, the results of complex simulation studies on the efficiency of the proposed method are described.
Atmospheric degradation mechanism of anthracene initiated by OH•: A DFT prediction
- Farzaneh Shahsavar
- Ehsan Zahedi
- Abolfazl Shiroudi
- Behzad Chahkandi
2023 JOURNAL OF MOLECULAR GRAPHICS & MODELLING
Density functional theory (DFT) calculations at the M06-2X/def2-TZVP level have been employed to investigate the atmospheric oxidation mechanism of anthracene (ANT) initiated by HO•. Direct hydrogen atom abstraction from the ANT using HO• takes place hardly at ambient conditions while the addition of HO• to the C1, C2, and C4 sites are thermodynamically and kinetically more advantageous. The addition reactions are controlled by the aromaticity and the kinetic trends were justified by resonance stabilization energies. The rate constants were calculated by using the Rice-Ramsperger-Kassel-Marcus (RRKM) and canonical transition state theory (CTST) methods in conjugation with zero curvature tunneling (ZCT). The overall RRKM-bimolecular rate constant at ambient conditions is 6.72 × 10−12 cm3 molecule−1 s−1, is negatively dependent on the temperature and can be expressed as k=3.92*10-14 exp(1534.9/T). Contribution of the AD-C4 path in the overall reaction is about 70–80%, implying that the dependence of overall rate constant on pressure can be ignored. The kinetic data exhibit that the ANT is degraded during its long-range transport in the atmosphere and cannot be classified as persistent organic pollutants.
Attention-Based Deep Learning System for Classification of Breast Lesions—Multimodal, Weakly Supervised Approach
- Maciej Bobowicz
- Marlena Rygusik
- Jakub Buler
- Rafał Buler
- Maria Ferlin
- Arkadiusz Kwasigroch
- Edyta Szurowska
- Michał Grochowski
2023 Pełny tekst Cancers
Breast cancer is the most frequent female cancer, with a considerable disease burden and high mortality. Early diagnosis with screening mammography might be facilitated by automated systems supported by deep learning artificial intelligence. We propose a model based on a weakly supervised Clustering-constrained Attention Multiple Instance Learning (CLAM) classifier able to train under data scarcity effectively. We used a private dataset with 1174 non-cancer and 794 cancer images labelled at the image level with pathological ground truth confirmation. We used feature extractors (ResNet-18, ResNet-34, ResNet-50 and EfficientNet-B0) pre-trained on ImageNet. The best results were achieved with multimodal-view classification using both CC and MLO images simultaneously, resized by half, with a patch size of 224 px and an overlap of 0.25. It resulted in AUC-ROC = 0.896 ± 0.017, F1-score 81.8 ± 3.2, accuracy 81.6 ± 3.2, precision 82.4 ± 3.3, and recall 81.6 ± 3.2. Evaluation with the Chinese Mammography Database, with 5-fold cross-validation, patient-wise breakdowns, and transfer learning, resulted in AUC-ROC 0.848 ± 0.015, F1-score 78.6 ± 2.0, accuracy 78.4 ± 1.9, precision 78.8 ± 2.0, and recall 78.4 ± 1.9. The CLAM algorithm’s attentional maps indicate the features most relevant to the algorithm in the images. Our approach was more effective than in many other studies, allowing for some explainability and identifying erroneous predictions based on the wrong premises.
Attenuation of Hyperglycemia in Diabetic Rats Assisted by Immobilized Probiotic in Sodium Alginate
- José J. Arriaga-Morales
- Cynthia Ordaz-Pichardo
- Roberto Castro Munoz
- Enrique Durán-Páramo
2023 Pełny tekst Probiotics and Antimicrobial Proteins
Diabetes mellitus type 2 (DM2) is the most common chronic disease worldwide, characterized mainly by increased glucose concentration in the blood and affecting several organs’ functionality. The daily consumption of probiotic bacteria can help control diabetes and reduce the damage caused. Cell immobilization techniques are a powerful tool that provides physical cell protection to such probiotic bacteria against gastrointestinal conditions. We suggest that cell immobilization could be a significant vector for delivering a high quantity of viable probiotics to the gut, helping attenuate hyperglycemia in diabetic rats. Seventy male Wistar rats were used in this work. Nicotinamide was administrated via intraperitoneal injection 15 minutes before inducing type 2 diabetes (DM2), followed by a second intraperitoneal injection of streptozotocin to induce DM2. Rats were divided into seven groups. For 45 days, a specific treatment was applied to each group. The group of rats, supplied with immobilized Lactobacillus casei, showed a serum glucose concentration of 137 mg/dL, which was close to the one observed in the groups of healthy rats (117 mg/dL) and rats treated with metformin (155 mg/dL). The diabetic rats without treatment presented a higher serum glucose concentration (461 mg/dL). In the rats treated with immobilized L. casei, there was no biochemical parameter alteration, and the cell morphology of the analyzed tissues was similar to those of the healthy group. The consumption of immobilized L. casei could allow a high quantity of viable probiotics to be delivered to the gut, reducing serum glucose concentration by up to 70% compared to diabetic rats and reducing organ damage caused by diabetes.
Attractors of dissipative homeomorphisms of the infinite surface homeomorphic to a punctured sphere
- Grzegorz Graff
- Rafael Ortega
- Alfonso Ruiz-Herrera
2023 Pełny tekst COMMUNICATIONS IN CONTEMPORARY MATHEMATICS
A class of dissipative orientation preserving homeomorphisms of the infinite annulus,pairs of pants, or generally any infinite surface homeomorphic to a punctured sphere isconsidered. We prove that in some isotopy classes the local behavior of such homeomor-phisms at a fixed point, namely the existence of so-called inverse saddle, impacts thetopology of the attractor — it cannot be arcwise connected
Audio Content and Crowdsourcing: A Subjective Quality Evaluation of Radio Programs Streamed Online
- Przemysław Falkowski-Gilski
2023
Radio broadcasting has been present in our lives for over 100 years. The transmission of speech and music signals accompanies us from an early age. Broadcasts provide the latest information from home and abroad. They also shape musical tastes and allow many artists to share their creativity. Modern distribution involves transmission over a number of terrestrial systems. The most popular are analog FM (Frequency Modulation) and digital DAB+ (Digital Audio Broadcasting plus). It is worth mentioning that the same content is delivered simultaneously in several techniques, referred to as simulcasting. In addition, the vast majority of radio stations broadcast the same audio content online as well. Their signals are available through dedicated mobile applications for popular mobile devices running the Android or iOS operating system. In turn, other broadcasters offer content through their own website or third-party services associating several radio programs. Such a situation may be observed both on the local (regional) and national (state) market all around the world in America, Europe, Asia, etc. When it comes to terrestrial radio, contrary to analog FM broadcasting, digital signals are grouped into a set, referred to as the multiplex ensemble. It should be emphasized that the costs associated with regular broadcasting of radio programs are much lower in case of the digital standard. The entire process and fees related to the collection and processing of audio signals and associated additional data, as well as the formation and emission of the multiplex collective signal, can be distributed among several or even a dozen shareholders. The total net bitrate can be flexibly distributed depending on the broadcaster’s profile and target audience, played music genre, etc., according to the established needs. Another approach related to the digital broadcasting of radio signals is the on-demand availability of content in the form of the so-called podcast. The listener is able to choose a previously recorded material through the web browser or a mobile application. Considering the number of available radio programs and the broad range of content they create, this form seems perfectly justified. In case of broadcasting radio programs online, referred to as streaming, speech and music signals and associated multimedia (e.g., album cover, author information, etc.) are available live in real-time. Of course, the transmission medium is different.
Audyt Krajobrazowy Województwa Pomorskiego. Karta Krajobrazu Priorytetowego. Żuławy: Wróblewo Opinia Ekspercka
- Marta Koperska-Kośmicka
2023
Opinia ekspercka dla Karty Krajobrazu Priorytetowego Żuławy: Wróblewo, symbol obszaru: 22-313.54-91, do Audytu Krajobrazowego Województwa Pomorskiego
Audyt Krajobrazowy Województwa Pomorskiego. Karta Krajobrazu Priorytetowego. Żuławy: Złotowo. Opinia Ekspercka
- Marta Koperska-Kośmicka
2023
Opinia ekspercka dla Karty Krajobrazu Priorytetowego Żuławy: Złotowo, symbol obszaru: 22-313.54-83, do Audytu Krajobrazowego Województwa Pomorskiego
Audyt Krajobrazowy Województwa Pomorskiego Opinia ekspercka dla Karty Krajobrazu Priorytetowego Nizina Walichnowska, symbol obszaru: 22-314.81-7
- Marta Koperska-Kośmicka
2023
Audyt Krajobrazowy Województwa Pomorskiego Opinia ekspercka dla Karty Krajobrazu Priorytetowego Nizina Walichnowska, symbol obszaru: 22-314.81-7
Audyt Krajobrazowy Województwa Pomorskiego. Opinia ekspercka dla Karty Krajobrazu Priorytetowego Żuławy: Kmiecin-Marynowy-Lubieszewo, symbol obszaru: 22-313.54-87
- Marta Koperska-Kośmicka
2023
Audyt Krajobrazowy Województwa Pomorskiego. Opinia ekspercka dla Karty Krajobrazu Priorytetowego Żuławy: Kmiecin-Marynowy-Lubieszewo, symbol obszaru: 22-313.54-87
Augmented speed control scheme of dual induction motors with mutual flux angle control loop
- Dmytro Kondratenko
- Arkadiusz Lewicki
- Krzysztof Łuksza
2023 Pełny tekst Archives of Electrical Engineering
This paper proposes an augmented speed control scheme of dual induction motors fed by a five-leg voltage source inverter (VSI) with a common/shared-leg. An additional control loop is proposed here and based on the mutual flux angle – the difference between flux angular positions of the IMs. The main purpose of this research is to minimize the energy losses in the common inverter leg by controlling the mutual flux angle, at equal angular speeds of both motors. Simulation and experimental studies were carried out and the effectiveness of the proposed control method was proven. The PLECS software package was used for the simulation tests. The laboratory prototype was prepared for the experimental validation. All results were provided and discussed in this paper.
Autistic Employees’ Technology-Based Workplace Accommodation Preferences Survey—Preliminary Findings
- Michał Tomczak
- Paweł Ziemiański
2023 Pełny tekst International Journal of Environmental Research and Public Health
Background: There has been an increase in the number of research studies focused on the design of accommodations aimed at improving the well-being and work performance of autistic employees. These accommodations took various forms; some of them were based on modification of management practices, for example, support in the area of effective communication, or involved modifications to the physical working environment aimed at limiting sensory vulnerabilities. Many of these solutions were based on digital technology. Methods: This quantitative research aimed to learn about the opinions of the autistic respondents as potential end users and their assessment of the proposed solutions within four main challenge areas: (1) effective communication; (2) time management, task prioritizing, and organization of work; (3) stress management and emotion control; and (4) sensory sensitivities. Results: Respondents gave the highest ratings to solutions aimed at limiting overstimulation and a flexible approach toward working time, support of a job coach, remote work, and support by allowing electronic-mediated communication based on non-direct contact. Conclusions: The results can be the starting point for further research on the highest rated solutions dedicated to improving working conditions and the well-being of autistic employees and can be an inspiration for employers who plan to introduce such solutions.
Autoencoder application for anomaly detection in power consumption of lighting systems
- Tomasz Śmiałkowski
- Andrzej Czyżewski
2023 Pełny tekst IEEE Access
Detecting energy consumption anomalies is a popular topic of industrial research, but there is a noticeable lack of research reported in the literature on energy consumption anomalies for road lighting systems. However, there is a need for such research because the lighting system, a key element of the Smart City concept, creates new monitoring opportunities and challenges. This paper examines algorithms based on the deep learning method using the Autoencoder model with LSTM and 1D Convolutional networks for various configurations and training periods. The evaluation of the algorithms was carried out based on real data from an extensive lighting control system. A practical approach was proposed using real-time, unsupervised algorithms employing limited computing resources that can be implemented in industrial devices designed to control intelligent city lighting. An anomaly detection algorithm based on classic LSTM networks, single-layer and multi-layer, was used for comparison purposes. Error matrix calculus was used to assess the quality of the models. It was shown that based on the Autoencoder method, it is possible to construct an algorithm that correctly detects anomalies in power measurements of lighting systems, and it is possible to build a model so that the algorithm works correctly regardless of the season of the year.
Automated anonymization of sensitive data on production unit
- Marcin Kujawa
- Robert Piotrowski
2023 Pełny tekst Journal of Automation, Mobile Robotics and Intelligent Systems - JAMRIS
The article presents an approach to data anonymization with the use of generally available tools. The focus is put on the practical aspects of using open-source tools in conjunction with programming libraries provided by suppliers of industrial control systems. This universal approach shows the possibilities of using various operating systems as a platform for process data anonymization. An additional advantage of the described approach is the ease of integration with various types of advanced data analysis tools based both on the out-of-the-box approach (e.g., business intelligence tools) as well as customized solutions. The discussed case describes the anonymization of data for the needs of sensitive analysis by a wider group of recipients during the construction of a predictive model used to support decisions.
Automated detection of pronunciation errors in non-native English speech employing deep learning
- Daniel Korzekwa
2023 Pełny tekst
Despite significant advances in recent years, the existing Computer-Assisted Pronunciation Training (CAPT) methods detect pronunciation errors with a relatively low accuracy (precision of 60% at 40%-80% recall). This Ph.D. work proposes novel deep learning methods for detecting pronunciation errors in non-native (L2) English speech, outperforming the state-of-the-art method in AUC metric (Area under the Curve) by 41%, i.e., from 0.528 to 0.749. One of the problems with existing CAPT methods is the low availability of annotated mispronounced speech needed for reliable training of pronunciation error detection models. Therefore, the detection of pronunciation errors is reformulated to the task of generating synthetic mispronounced speech. Intuitively, if we could mimic mispronounced speech and produce any amount of training data, detecting pronunciation errors would be more effective. Furthermore, to eliminate the need to align canonical and recognized phonemes, a novel end-to-end multi-task technique to directly detect pronunciation errors was proposed. The pronunciation error detection models have been used at Amazon to automatically detect pronunciation errors in synthetic speech to accelerate the research into new speech synthesis methods. It was demonstrated that the proposed deep learning methods are applicable in the tasks of detecting and reconstructing dysarthric speech.
Automatic audio signal mixing system based on one-dimensional Wave-U-Net autoencoders
- Damian Koszewski
2023 Pełny tekst
The purpose of this dissertation is to develop an automatic song mixing system that is capable of automatically mixing a song with good quality in any music genre. This work recalls first the audio signal processing methods used in audio mixing, and it describes selected methods for automatic audio mixing. Then, a novel architecture built based on one-dimensional Wave-U-Net autoencoders is proposed for automatic music mixing. Models are trained on a custom-made database. Mixes created using the proposed system are compared with amateur, state-of-the-art software and professional mixes prepared by audio engineers. The achieved results prove that mixes created automatically by Wave-U-Net can objectively be evaluated as highly as mixes created professionally. This is also confirmed by the statistical analysis of the results of the conducted listening tests. The results show a strong correlation between the experience of the listeners in mixing and the likelihood of a higher rating of the Wave-U-Net mix and the professional mix than the amateur mix or the mix prepared using state-of-the-art software. These results are also confirmed by the results of the similarity matrix-based analysis.