2024 - Repozytorium publikacji - Politechnika Gdańska

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A Mammography Data Management Application for Federated Learning
- Dmytro Tkachenko
- Magdalena Mazur-Milecka
2024
This study aimed to develop and assess an application designed to enhance the management of a local client database consisting of mammographic images with a focus on ensuring that images are suitably and uniformly prepared for federated learning applications. The application supports a comprehensive approach, starting with a versatile image-loading function that supports DICOM files from various medical imaging devices and settings. It also aims to standardize the labeling and pre-processing of new images, statistical analysis and data visualization of mammographic images across all participating healthcare units. Initial image preprocessing is significantly enhanced through the use of Wiener and CLAHE filters, aimed at reducing noise and improving contrast, respectively, to ensure the highest quality of images for diagnostic purposes. Further refinement in the preprocessing pipeline is achieved with a U-Net model, trained on publicly available databases, which excels in segmenting the breast tissue from images, thereby eliminating irrelevant background and artifacts. This meticulous preparation of images not only standardizes data quality across multiple medical institutions but also facilitates collaborative model training within federated learning frameworks. The program allows for the review of images and their metadata, enables labeling of images with the ability to mark regions of interest (ROI), and utilize a pre-trained model for preliminary BI-RADS classification. A notable addition to the application is the integration of functionalities, thanks to the implementation of Grad-CAM model, designed to elucidate the decision-making processes of deep learning models. This integration further enriches the application's utility in supporting diagnostic and analytical tasks in mammography, providing clear insights into the interpretive reasoning behind model predictions.
A method to synthesise groove cam Geneva mechanisms with increased dwell period
- Viacheslav Pasika
- Pavlo Nosko
- Oleksii Nosko
- Oleksandr Bashta
- Volodymyr Heletiy
- Volodymyr Melnyk
2024 Pełny tekst PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE
The present study develops a method to synthesise the groove cam Geneva mechanism with increased dwell period. The main condition of the synthesis is to provide the desired law of motion of the wheel. Additional synthesis conditions are the limitation of the maximum pressure angle and the limitation of the minimum curvature radius of the cam profile. Unlike the conventional Geneva mechanisms, the synthesised groove cam Geneva mechanisms enable motion of the wheel due to an arbitrarily specified law, double locking of the wheel at its dwell-to-motion and motion-to-dwell transitions, absence of soft impacts in the extreme positions. The analysis shows that for the cycloidal law of motion, number of slots in range 3 to 15 and additional dwell coefficient in range 0 to 0.7, the operating time coefficient can be provided in wide range from 0.053 to 0.765. The effectiveness of the method is illustrated by numerical examples.
A methodology for ultimate strength assessment of ship hull girder accounting for enhanced corrosion degradation modelling
- Krzysztof Wołoszyk
- Floris Goerlandt
- Jakub Montewka
2024 MARINE STRUCTURES
The presented work shows a methodology for the ultimate strength assessment of a ship hull, considering enhanced corrosion modelling. The approach is based on the classical Smith method. However, the recent findings regarding the impact of corrosion degradation on ultimate strength are incorporated. To this end, the stress–strain relationships for particular elements composing ship hull cross-section are modified using a specially developed correction factor. The proposed approach is validated with experimental results of the corroded box girders available in the literature, showing very good agreement. Further, a case study of a VLCC tanker ship is presented, and a comparison between contemporary and enhanced corrosion degradation modelling in terms of resulting ultimate strength is presented. The results indicate that the currently used method may significantly overestimate the hull’s structure capacity, especially considering the long exploitation period. Thus, current approaches lead to a non-conservative assessment of the ship hull girder’s ultimate strength, potentially increasing the risk of failure. It is therefore recommended to further investigate the proposed method, especially in the context of risk-based ship design approaches and holistic maritime transportation risk management.
A model for agribusiness supply chain risk management using fuzzy logic. Case study: Grain route from Ukraine to Poland
- Ievgen Medvediev
- Dmitriy Muzylyov
- Jakub Montewka
2024 Pełny tekst TRANSPORTATION RESEARCH PART E-LOGISTICS AND TRANSPORTATION REVIEW
In order to establish new logistics routes, it is necessary to address several technical and organizational issues, among others. One of the most important criteria for evaluating the performance of a supply chain is the delivery time, proactive consideration of potential hazards and associated uncertainties that may occur along the route. However, the existing solutions are often passive and reactive, based on statistics, thus not leaving much room for proactive risk mitigation measures. Therefore, there is a need for a foreseeing modern approach to account for the impact of anticipated hazards on delivery time. The aim of this study is to develop a model for determining delivery time considering expected risk factors (RF), based on mathematical tools of fuzzy logic and actual background knowledge elicited from the literature and experts. The paper identifies primary technical and operational hazards that occur during loading and transport and converts them into risk factors. The risk factors are then quantified and fed into a fuzzy model developed with the Matlab Fuzzy Logic Toolbox and assembled in the Simulink environment. The application of the model is demonstrated in three case studies reflecting three potential grain supply chains (SC) from Ukraine to Poland: classical transport by rail grain hoppers (SC1); transport by containers on railway platforms (SC2); transport by bulk grain trucks (SC3). The resulting travel time for the analysed SCs is between 49 and 71 hours for SC1, between 45 and 62 hours for SC2 and between 42 and 62 hours for SC3. In addition, the outliers of the travel time values beyond the 1.5 quantiles were defined according to the uncertainty band. The results of the fuzzy model were compared with the results of the deterministic approach in the concurrent validation and a good agreement was found. This proves the appropriateness of the fuzzy model calculations and the possibility of using alternative SCs in grain delivery. The main benefit of the proposed model is a new universal tool based on a holistic and active approach to risk assessment using fuzzy logic.
A Model Modification for a Microturbine Set with Partial Admission Stages
- Wojciech Włodarski
- Marian Piwowarski
2024 ENERGIES
The vapour microturbine set’s mathematical model has been updated to consider the partial admission of turbine stages. Experimental data from two distinct microturbine sets were used to verify the model. The model of the microturbine set was tested under varying operating conditions. Examples of a comparison between the experimental results and simulations are presented and analysed. It has been shown that, when simulating the off-design operation of multistage microturbines, not taking into account power losses due to partial admission may lead to significantly incorrect results. This conclusion does not apply to single-stage microturbines.
A modified DC Hebb–Wagner polarization method for determining the partial protonic electrical conductivity in mixed-conducting BaGd0.3La0.7Co2O6−δ
- Tadeusz Miruszewski
- Ragnar Strandbakke
- Kacper Dzierzgowski
- Iga Szpunar
- Aleksandra Mielewczyk-Gryń
- Sebastian Wachowski
- Maria Gazda
2024 Journal of Materials Chemistry A
In this work, partial protonic conductivity in mixed conducting (BZCY721) and BaGd0.3La0.7Co2O6−d (BGLC137) was studied. For this purpose, a modified DC Hebb–Wagner polarization method was used. A four-wire type of galvanic cell as well as a suitable calculation model was applied. The method was validated using proton conducting electrolyte – BaZr0.7Ce0.2Y0.1O3−d – as a reference material. For the first time, protonic partial conductivity in BaGd0.3La0.7Co2O6−d was determined. It was found that at 600 °C its total conductivity was ∼550 S cm−1, whereas the partial protonic conductivity under the same conditions was 4.4 × 10−5 S cm−1 (protonic transference number of 7.6 × 10−8). Therefore, the proposed measurement cell and the applied model allowed for the determination of a minor protonic conductivity in the BGLC137 electronic conductor.
A multiparameter simulation-driven analysis of ship response when turning concerning a required number of irregular wave realizations
- Przemysław Krata
- Mateusz Gil
- Tomasz Hinz
- Paweł Kozioł
2024 OCEAN ENGINEERING
The growing implementation of Decision Support Systems on modern ships, digital-twin technology, and the introduction of autonomous vessels cause the marine industry to seek accurate modeling of vessel response. Despite the contemporary 6DOF models can be used to predict ship motions in irregular waves, the impact of their stochastic realization is usually neglected and remains under-investigated. Especially in the case of turning, differences arising from the stochastic representation of the waves may result in excessive ship motions or even stability failure during maneuver execution. Therefore, in this study, statistical distributions of maximum amplitudes of roll, pitch, and lateral acceleration calculated in two representative locations on board a passenger vessel were analyzed concerning stochastic wave realization and existing extremes. The research utilized 6DOF simulation data and numerous realizations of the irregular wave with random phases of its components. Furthermore, the required number of wave realizations allowing for capturing the actual ranges of ship response at an assumed confidence level has been determined and analyzed. Ultimately, the results were compared in the safety-critical cases concerning various wave and operational conditions. The outcome of this study may be found useful by all parties involved in developing maritime autonomous systems and modeling ship motions.
A multiparameter simulation-driven analysis of ship turning trajectory concerning a required number of irregular wave realizations
- Mateusz Gil
- Przemysław Krata
- Paweł Kozioł
- Tomasz Hinz
2024 OCEAN ENGINEERING
In times of progressive automation of the marine industry, accurate modeling of ship maneuvers is of utmost importance to all parties involved in maritime transportation. Despite the existence of modern collisionavoidance algorithms using 6DOF motion models to predict ship trajectories in waves, the impact of stochastic realization of irregular waves is usually neglected and remains under-investigated. Therefore, herein, this phenomenon and its impact were investigated in the case study of the passenger ship’s turning. To this end, statistical and spatiotemporal distributions of ship positions and corresponding trajectory parameters were analyzed. This was made using massive 6DOF simulation data with particular attention to the observed extremes. Additionally, the minimum number of wave realizations has been determined using different methods in various simulation scenarios and afterward compared concerning parameters’ impact and existing dependencies. The results indicate that for simulated scenarios, the required number of wave realizations should be at least 20, but in rough seas should be greater than 30. These values satisfy an acceptable and operationally reasonable error limit reaching 15% of the ship’s length overall. The obtained results may be of interest to autonomous ship developers, scholars, and marine industry representatives working on intelligent collision-avoidance solutions and ship maneuvering models.
A New Approach of Solidification Analysis in Modular Latent Thermal Energy Storage Unit Based on Image Processing
- Rafał Andrzejczyk
- Muhammad Saqib
- Michał Rogowski
2024 Pełny tekst APPLIED THERMAL ENGINEERING
The solidification process of RT18HC in a cylindrical shell and tube storage unit has been studied using a new methodology based on image processing. The main idea of the algorithm is to label the region of solidification and use statistical functions to calculate the dimensions of the solidification front over time. Said analysis includes two methods. The first method is to measure the solid fraction changes during solidification. The novelty of this method, as compared to other literature findings, is that pre-processing and calculation process occurs automatically via a calculation algorithm. This method is used to calculate the solid fraction of RT18HC which is reported to be a bit fast at the beginning that 40 % of its volume solidified in 1000 s while the rest of the process is completed in almost 6500 s. The second method is used to measure and calculate the thickness of the solid front by using image processing. This method’s error is calculated to be less than 7% throughout the entire process. The second method also acts as an experimental database of front thickness to use in a novel, simplified, semi-theoretical model proposed to calculate the solid front thickness as a function of time in this paper. It is also worth presenting solution extended by a general definition of thermal resistance for a cylindrical partition. The above study will enable the development of an enhanced and optimized model for complex geometries based on image processing techniques in the future. It will also allow the investigation of both processes i.e. solidification and melting alongside other influencing parameters such as the geometry of the storage unit in future.
A new strategy for PET depolymerization: Application of bimetallic MOF-74 as a selective catalyst
- Mateusz Baluk
- Patrycja Jutrzenka Trzebiatowska
- Aleksandra Pieczyńska
- Damian Makowski
- Malwina Kroczewska
- Justyna Łuczak
- Adriana Zaleska-Medynska
2024 JOURNAL OF ENVIRONMENTAL MANAGEMENT
Large-volume production of poly(ethylene terephthalate) (PET), especially in the form of bottles and food packaging containers, causes problems with polymer waste management. Waste PET could be recycled thermally, mechanically or chemically and the last method allows to obtain individual monomers, but most often it is carried out in the presence of homogeneous catalysts, that are difficult to separate and reuse. In view of this, this work reports for the first time, application of bimetallic MOF-74 – as heterogeneous catalyst - for depolymerization of PET with high monomer bishydroxyethyl terephthalate, BHET) recovery. The effect of type and amount of second metal in the MOF-74 (Mg/M) was systematically investigated. The results showed increased activity of MOF-74 (Mg/M) containing Co2+, Zn2+ and Mn2+ as a second metal, while the opposite correlation was observed for Cu2+ and Ni2+. It was found that the highest catalytic activity was demonstrated by the introduction of Mg–Mn into MOF-74 with ratio molar 1:1, which resulted in complete depolymerization of PET and 91.8% BHET yield within 4 h. Furthermore, the obtained catalyst showed good stability in 5 reaction cycles and allowed to achieve high-purity BHET, which was confirmed by HPLC analysis. The as-prepared MOF-74 (Mg/Mn) was easy to separate from the post-reaction mixture, clean and reuse in the next depolymerization reaction.
A note on the Morse homology for a class of functionals in Banach spaces involving the 2p-area functional
- Luca Asselle
- Maciej Starostka
2024 NODEA-NONLINEAR DIFFERENTIAL EQUATIONS AND APPLICATIONS
In this paper we show how to construct Morse homology for an explicit class of functionals involving the 2p-area functional. The natural domain of definition of such functionals is the Banach space W_0^{1,2p}(\Omega), where p > n/2 and \Omega \subet R^n is a bounded domain with sufficiently smooth boundary. As W_0^{1,2p}(\Omega) is not isomorphic to its dual space,critical points of such functionals cannot be non-degenerate in the usual sense, and hence in the construction of Morse homology we only require that the second differential at each critical point be injective. Our result upgrades, in the case p > n/2 , the results in Cingolani and Vannella (Ann Inst H Poincaré Anal Non Linéaire 2:271–292, 2003; Ann Mat Pura Appl 186:155–183, 2007), where critical groups for an analogous class of functionals are computed, and provides in this special case a positive answer to Smale’s suggestion that injectivity of the second differential should be enough for Morse theory
A Novel [4+2] Cycloaddition Reaction Involving Lawesson’s Reagent. Structure and Specific Fragmentations of a New Cyclic 1,2-Thiaphosphinane-4-one
- Witold Przychodzeń
- Barbara Kusznierewicz
2024 PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
A crude morpholine enamine of acetone treated with Lawesson’s reagent unexpectedly yielded a six-membered thiaphosphinane-4-one. This compound is the first example of a new class of heterocycles. It has been proven that it is formed from 4-methyl-2-morpholino-1,3-pentadiene which is usually present in crude morpholine enamine batches. A mechanism of this regioselective reaction was postulated and a characteristic chair-like conformation of the product was examined in detail. Additionally, some unusual primary fragmentations of the product with the loss of H2S and isobutylene were observed for positive and negative ESI ionization mode, respectively.
A novel approach to enhance high optically active L-lactate production from food waste by landfill leachate
- Wenjuan Zhang
- Jiaxin Shi
- Yue Li
- Yonghong Ma
- Aisha Khanzada
- Hussein Al-Hazmi
- Xianbao Xu
- Xiang Li
- Gamal K. Hassan
- Gang Xue
- Jacek Mąkinia
2024 Pełny tekst JOURNAL OF ENVIRONMENTAL MANAGEMENT
The recycling of food waste (FW) through anaerobic fermentation into lactic acid (LA), with two isomers L-LA and D-LA, aligns with the principles of a bio-based circular economy. However, FW fermentation is often limited by competing pathways, acidification inhibition, and trace metals deficiency. This study investigates the introduction of landfill leachate, containing buffering agents (ammonia) and trace metals, into FW fermentation. Various dosages of landfill leachate, ranging from 90 (LN-90) to 450 mg/L (LN-450) based on inclusive ammonia calculation, were employed. Results showed that LA production peaked at 43.65 ± 0.57 g COD/L in LN-180 on day 6, with a high optical activity of L-LA at 92.40 ± 1.15 %. Fermentation pathway analysis revealed that landfill leachate amendment enhances hydrolysis (as evidenced by increased activity of amylase, α-glucosidase, and protease) and glycolysis (resulting in enhanced utilization of carbohydrates and glucose). The inclusive ammonia in leachate plays a crucial role as a buffer, maintaining optimal pH conditions (5–7), thereby reducing volatile fatty acid production and thus intensifying LA orientations. The increased activity of L-lactate dehydrogenase (L-LA generation) and decreased NAD-independent lactate dehydrogenase (LA consumption) in properly dosed leachate further explained the high accumulation of L-LA. Dominance of lactic acid bacteria, including Streptococcus, Enterococcus, Klebsiella, Bifidobacterium, Bavariicoccus, and Lacticaseibacillus, accounted for 91.08% (LN-90), while inhibitory effects were observed in LN-450 (4.45%). Functional gene analysis further supported the enhanced glycolysis, L-lactate dehydrogenase, and nitrogen assimilation. Finally, a network analysis indicates a beneficial effect on the genus Enterococcus and Klebsiella by landfill leachate addition. This study demonstrates the efficiency of utilizing landfill leachate to enhance LA recycling from FW fermentation, aligning with the concept of circular economy by transforming waste into valuable resources.
A Novel Device and System for Fall Detection Under the Shower
- Adam Bujnowski
- Bartłomiej Rajzer
- Aleksey Andrushevich
- Artur Poliński
- Mariusz Kaczmarek
- Jerzy Wtorek
2024
In this paper, device construction and preliminary results for shower safety assistance are presented. The device allows monitoring of shower-taking persons without violating privacy and intimacy, while it has the ability to detect a persons entering and leaving the shower and detecting fall conditions. It allows better supervision of elders living independently at their locations.
A Novel Iterative Decoding for Iterated Codes Using Classical and Convolutional Neural Networks
- Marek Blok
- Bartosz Czaplewski
2024
Forward error correction is crucial for communication, enabling error rate or required SNR reduction. Longer codes improve correction ratio. Iterated codes offer a solution for constructing long codeswith a simple coder and decoder. However, a basic iterative code decoder cannot fully exploit the code’s potential, as some error patterns within its correction capacity remain uncorrected.We propose two neural network-assisted decoders: one based on a classical neural network, and the second employing a convolutional neural network. Based on conducted research, we proposed an iterative neural network-based decoder. The resulting decoder demonstrated significantly improved overall performance, exceeding that of the classical decoder, proving the efficient application of neural networks in iterative code decoding.
A novel section–section potential for short-range interactions between plane beams
- A. Borković
- M.h. Gfrerer
- Roger Sauer
- B. Marussig
- T.q. Bui
2024 Pełny tekst COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
We derive a novel formulation for the interaction potential between deformable fibers due to short-range fields arising from intermolecular forces. The formulation improves the existing section–section interaction potential law for in-plane beams by considering an offset between interacting cross sections. The new law is asymptotically consistent, which is particularly beneficial for computationally demanding scenarios involving short-range interactions like van der Waals and steric forces. The formulation is implemented within a framework of rotation-free Bernoulli–Euler beams utilizing the isogeometric paradigm. The improved accuracy of the novel law is confirmed through thorough numerical studies. We apply the developed formulation to investigate the complex behavior observed during peeling and pull-off of elastic fibers interacting via the Lennard–Jones potential.
A Numerical Model Study on Grasse River Ice Control Structures
- Tomasz Kolerski
- Hung Tao Shen
2024 Pełny tekst CANADIAN JOURNAL OF CIVIL ENGINEERING
Ice jams in the Grasse River have caused the erosion of capping material designed to prevent the resurfacing of the bed sediment in the PCB-contaminated area. Two in-stream ice-control structures are proposed to avoid the jam-induced erosion of the capping material. These two ice-control options are a pier-type ice-control structure and a reconstruction of a small hydropower dam upstream of the capping site. A numerical model study using the DynaRICE model is conducted to evaluate the effectiveness of the proposed design. Flow and ice conditions corresponding to the 100-year return period of ice jam events obtained from analyzing historical breakup ice jam data are used in the evaluation. The results showed that these ice-control structures could reduce the ice discharge downstream and the size of the ice jam at the capping site to prevent the erosion and scour of the PCB-contaminated bed.
A palatal prosthesis from archaeological research in the St Francis of Assisi church in Cracow (Poland)
- Anna E. Spinek
- Marta Kurek
- Krzysztof Demidziuk
- Marcin Nowak
- Magdalena Śliwka-Kaszyńska
- Anna Drążkowska
2024 Journal of Archaeological Science-Reports
The hard palate is a septum that not only prevents food from entering between the oral and nasal cavity, but also plays an important role during breathing or speech. The presence of cavities within it negatively affects the comfort of life of people with this type of impairment. Hence, in the literature one can find examples of the use of hard palate prostheses to restore the separation between the nasal and oral cavity. During archaeological research conducted in 2017–18 in the church of St Francis of Assisi in Cracow, the remains of a man with a cleft palate, who died at the age of about 50, were found. His burial is dated to the eighteenth century. Within his mouth, the presence of a palatal prosthesis was noted. This is the first case in Poland of finding an individual with an obturator tailored to its needs. The aim of the work is to present the structure and elemental composition of the found prosthesis and comparisons to the other obturators known from written sources. Macroscopic analysis showed the presence of an elliptical-shaped metal diaphragm and a textile “tampon” entering nasal cavity. The metal part of the prosthesis was made of copper alloy, covered with a layer of silver and gold. The comparison of the analysed obturator with examples from the literature indicates its great similarity to those used in the sixteenth and eighteenth centuries.
A Planar-Structured Circularly Polarized Single-Layer MIMO Antenna for Wideband Millimetre-Wave Applications
- Ubaid Ullah
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
- Shahanawaz Kamal
2024 Pełny tekst Engineering Science and Technology-An International Journal-JESTECH
In this paper, a simple geometry, planar-structured printed multiple-input-multiple-output (MIMO) antenna utilizing dual circular polarization (CP) is presented. The proposed numerically and experimentally validated design features a fully grounded coplanar waveguide (CPW) and a systematically perturbed feedline radiator. The fringing electric (E) field along the feedline is altered by extruding periodic stubs on each side of the microstrip line extended from a grounded CPW. The different physical size of the stubs on each side, plus a slight offset introduced between the stubs breaks the symmetry of the vector E-fields on both side of the edges. The asymmetric E-field weakens the intensity of the respective magnetic current on the opposite side for a wider spectrum, resulting in a wideband operation. The asymmetric vertical magnetic current along the length of the stubs and the combined current on the horizontal edges yield 90-degree out-of-phase orthogonal field components, radiating circularly polarized waves. The proposed design has the advantage of topological simplicity and ease of polarization sense alteration. Owing to this, the design is implemented in MIMO configuration with each port radiating a different sense of CP. The antenna's simulated and measured -10 dB impedance bandwidth is more than 26.5% ranging from 24.6 GHz to 32.1 GHz frequency. Additionally, the antenna retains an axial ratio (AR) of 3 dB or less from 26 GHz to 31.8 GHz. The peak realized gain (RG) of the antenna is 10.3 dBic with an average value of ~ 9.5 dBic across the bandwidth confirming stable radiation in the broadside direction. At the same time, the envelop correlation coefficient and the diversity gain are about 0.01 and 10 dB, respectively over the operating band.
A Probabilistic Optimisation Approach to the Equitable Controller Location Problem
- Erison Ballasheni
- Dritan Nace
- Artur Tomaszewski
- Alban Zyle
2024 IEEE Transactions on Network and Service Management
The ability of the Software-Defined Network (SDN) to transport traffic flows depends, in particular, on the SDN switches being able to communicate with SDN controllers, which are responsible for the setup of network connections and the configuration of switches. Since in principle the number of SDN controllers is limited they must be installed in a set of carefully selected node locations. Whereas the problem of controller placement is well defined and has been thoroughly studied and effectively solved for the nominal network state, it becomes difficult when the network is subject to attacks, especially as they can occur anywhere and anytime. In this paper we tackle the problem of controller placement resilient to network attacks considering probabilistic characterisation of attacks and equitable access of switches to controllers. We treat the problem as a specific facility location problem with the objective of providing resilience to network attacks, and analyze a couple of major solution fairness criteria. We derive a number of Mixed-Integer Linear Programming (MILP) problem models that exploit robust optimization and fair optimization concepts and techniques, and examine their effectiveness by means of a numerical study that uses five transport networks.