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Search results for: MACHINE LEARNING, 3D-PRINTED FIBER REINFORCED CONCRETE, MODEL INTERPRETABILITY, COMPRESSIVE STRENGTH
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Evaluation of aspiration problems in L2 English pronunciation employing machine learning
PublicationThe approach proposed in this study includes methods specifically dedicated to the detection of allophonic variation in English. This study aims to find an efficient method for automatic evaluation of aspiration in the case of Polish second-language (L2) English speakers’ pronunciation when whole words are analyzed instead of particular allophones extracted from words. Sample words including aspirated and unaspirated allophones...
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3D Printing of Metallic Implants
PublicationThe fabrication of various elements, solid and open porous structures of stainless steel and Ti alloy is described. The process was started with the design of 3D models in CAD/CAM system. The 3D models were transformed into *.stl files and then the manufacturing process of the real structures by means of the selective laser melting with the SLM Realizer 100 3D printer was made. The paper shows the porous specimens made for possible...
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Effects of Xanthan Gum Biopolymer on the Permeability, Odometer, Unconfined Compressive and Triaxial Shear Behavior of a Sand
PublicationBiopolymers, which are microbially induced polymers, can be used as an alternative material to improve engineering performance of soils. In this paper, a laboratory study of 0.075-1.0 mm size sand and biopolymer (i.e., xanthan gum) mixtures with various mix ratios (0%, 0.5%, 1.0%, and 1.5%) was performed. The materials, specimen preparation, and test methods are described, as are the results of a suite of permeability, odometer, unconfined...
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Change in the Low-Cycle Performance on the 3D-Printed Materials ABS, ASA, HIPS, and PLA Exposed to Mineral Oil
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A model of damaged media used for describing the process of non-stationary creep and long-term strength of polycrystalline structural alloys
PublicationThe main laws of the processes of creep and long-term strength of polycrystalline structural alloys are considered. From the viewpoint of continuum damaged media (CDM), a mathematical model is developed that describes the processes of viscoplastic deformation and damage accumulation under creep. The problem of determining material parameters and scalar functions of the developed constitutive relations based on the results of specially...
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Interpretable deep learning approach for classification of breast cancer - a comparative analysis of multiple instance learning models
PublicationBreast cancer is the most frequent female cancer. Its early diagnosis increases the chances of a complete cure for the patient. Suitably designed deep learning algorithms can be an excellent tool for quick screening analysis and support radiologists and oncologists in diagnosing breast cancer.The design of a deep learning-based system for automated breast cancer diagnosis is not easy due to the lack of annotated data, especially...
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Evaluation of Mechanical Properties of Two-Stage Concrete and Conventional Concrete Using Nondestructive Tests
PublicationDifferent types of concrete mixtures are used as building materials. The manufacturing process of two-stage concrete (TSC) differs from that of conventional concrete. This study investigated conventional mechanical properties derive empirical relations for estimation of the mechanical parameters of TSC and conventional concrete mixtures. TSC was used to prepare 216 specimens and conventional concrete was used to prepare 108 specimens...
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The influence of core material on strength properties of hybrid sandwich panels
PublicationAlong with high prices of fuels and more restrictive safety and environmental regulations (including environment protection) increased interest in sandwich structures is being observed. One of the solution having growing application potential is steel sandwich panel. The construction consist of very thin steel plates (about 2mm) and stiffeners between them. The main advantage of using such solution is very high strength to weight...
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Lifelong Learning Idea in Architectural Education
PublicationThe recent advances in IT and technology are forcing changes in the approach to educating society. In the 20th century, life-long learning was understood as educating adults in order to improve their occupational qualifications. Life-long learning allows the needs of the present-day world to be addressed through providing the individual with education at every stage of his/her life various forms. The search for a new model...
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Fracture simulations in concrete beam under bending using a mesoscopic model with cohesive elements
PublicationThe main aim of this paper was to investigate a complex fracture process in a concrete beam subjected to 3-point bending test by means of the 2D meso-scale FEM with 4-node cohesive elements embedded in the initial mesh of 3-node solid elements. The material heterogeneity was taken into account by considering 3 different phases (aggregate, cement matrix, ITZs) on the basis of randomly generated internal structure of concrete and...
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublicationThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...
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Application of 3D printing metal powder technology in the manufacture of components with complex geometries
PublicationThe possibilities of using 3D printing powder technologies for making objects with complex geometries were presented. For this purpose, selected examples of elements with different geometries were used, which were built using metal powder methods – DMLS (direct metal laser sintering) / SLM (selective laser melting). Simultaneously, the indicated elements concern those areas of industry where 3D printing technology has been widely...
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Knowledge sharing and knowledge hiding in light of the mistakes acceptance component of learning culture- knowledge culture and human capital implications
PublicationPurpose: This study examines the micromechanisms of how knowledge culture fosters human capital development. Method: An empirical model was developed using the structural equation modeling method (SEM) based on a sample of 321 Polish knowledge workers employed in different industries. Findings: This study provides direct empirical evidence that tacit knowledge sharing supports human capital, whereas tacit knowledge hiding does...
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Non-linear circuit model of a single doubly-fed induction machine formulated in natural axes for drive systems simulation purposes
PublicationMathematical modelling and a circuit model formulated in natural axes of a single doubly-fed induction machine, with the account of magnetic circuit nonlinearity are presented in the paper. Derivation of the model differential equations was based on Lagrange's energy method. State functions of magnetic elements in the model are non-linear and depend on all currents flowing in the machine windings and on the angle of rotor position....
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A Quality Model for UML tools
PublicationJakość narzędzi UML wpływa na efektywność wykonywania zadań związanych z modelowaniem systemów w procesie wytwarzania oprogramowania. Celem badań prezentowanych w tym referacie jest wyodrębnienie kryteriów jakości narzędzi UML. Omówiono rolę narzędzi UML w projekcie informatycznym, a następnie zaprezentowano szereg kryteriów jakości narzędzi UML wraz z aspektami oceny oraz opisem ankiety, która służy do oceny narzędzi względem...
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The elasto-viscoplstic Chaboche model
PublicationW artykule przedstawiono rozwoj i numeryczną aplikacje sprężysto-lepkoplastycznego modelu Chabocha. Przedstawione są także szczegółowe opisy kilkunastu wariantów modelu Chaboche'a wraz z parametrami materiałowymi.
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MACHINE VISION DETECTION OF THE CIRCULAR SAW VIBRATIONS
PublicationDynamical properties of rotating circular saw blades are crucial for both production quality and personnel safety. This paper presents a novel method for monitoring circular saw vibrations and deviations. A machine vision system uses a camera and a laser line projected on the saw’s surface to estimate vibration range. Changes of the dynamic behaviour of the saw were measured as a function of the rotational speed. The critical rotational...
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Precise Identification of Different Cervical Intraepithelial Neoplasia (CIN) Stages, Using Biomedical Engineering Combined with Data Mining and Machine Learning
PublicationCervical cancer (CC) is one of the most common female cancers worldwide. It remains a significant global health challenge, particularly affecting women in diverse regions. The pivotal role of human papillomavirus (HPV) infection in cervical carcinogenesis underscores the critical importance of diagnostic strategies targeting both HPV infection and cervical...
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Predicting Performance of Lightweight Concrete with Granulated Expanded Glass and Ash Aggregate by Means of Using Artificial Neural Networks
PublicationLightweight concrete (LWC) is a group of cement composites of the defined physical, mechanical, and chemical performance. The methods of designing the composition of LWC with the assumed density and compressive strength are used most commonly. The purpose of using LWC is the reduction of the structure’s weight, as well as the reduction of thermal conductivity index. The highest possible strength, durability and low thermal conductivity...
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Size effect in concrete under splitting tension
PublicationThe size effect is a fundamental phenomenon in concrete materials. It denotes that both the nominal structural strength and material ductility always decrease with increasing element size under tension. In the paper splitting tensile tests on cylindrical concrete specimens with the different diameter were carried out. Two types of the loading strip (plywood board and steel cylinder) were used. The concrete strength and ductility...
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Compressive Sensing Approach to Harmonics Detection in the Ship Electrical Network
PublicationThe contribution of this paper is to show the opportunities for using the compressive sensing (CS) technique for detecting harmonics in a frequency sparse signal. The signal in a ship’s electrical network, polluted by harmonic distortions, can be modeled as a superposition of a small number of sinusoids and the discrete Fourier transform (DFT) basis forms its sparse domain. According to the theory of CS, a signal may be reconstructed...
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The Effect of Powder and Emulsion Binders on the Tribological Properties of Particulate Filled Glass Fiber Reinforced Polymer Composites
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Static and dynamic concrete calculations: Breakable aggregates in DEM model
PublicationThe paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic...
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Experimental Study of the Resistance to Influence of Aggressive Liquids on Lightweight Concrete
PublicationIn light of the scientific research, the corrosion of concrete structures is one of the main problems that may reduce their durability due to the negative impact of the natural environment. The paper analyzes the influence of the type of component on the selected properties of lightweight concrete subjected to the influence of aggressive liquids. Four concrete mixes were prepared with a granular aggregate made of foamed glass (GEGA)...
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The silver layers in fiber-optic sensors
PublicationIn this paper a method of application of the silver layers on the surface of an optical fiber was proposed. The optical properties and surface quality of the silver layer was examined by optical microscopy. The reflection and transmission of the sample were investigated. To evaluate the silver mirror it was placed in a fiber optic Fabry-Perot interferometer and the quality of the spectra was analyzed. The commercial mirror was...
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Characterization of Highly Filled Glass Fiber/Carbon Fiber Polyurethane Composites with the Addition of Bio-Polyol Obtained through Biomass Liquefaction
PublicationThis work aims to investigate the process of obtaining highly filled glass and carbon fiber composites. Composites were manufactured using previously obtained cellulose derived polyol, polymeric methylene diphenyl diisocyanate (pMDI). As a catalyst, dibutyltin dilaurate 95% and Dabco® 33-LV were used. It was found that the addition of carbon and glass fibers into the polymer matrix causes an increase in the mechanical properties...
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Control system based on the modified multiscalar model for the double fed machine
PublicationPrzedstawiono układ sterowania maszyną asynchroniczą dwustronnie zasilaną wykorzystujący zmodyfikowany model multisaklarny. Wprowadzone nielinowe sprzężenia pozwalają na podział systemu na dwa niezależne podukłady. Pododuje to brak zauważalnych sprzężeń przy regulacji mocy czynnej i biernej regulowanej przez kontrolery PI. W układzie wyeliminowano konieczność stosowania kaskadowego połączenia regulatorów. Przedstawiono wyniki symulacji.
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Performance analysis of an rfid-based 3d indoor positioning system combining scene analysis and neural network methods
PublicationThe main purpose of this research is to improve localization accuracy of an active Radio Frequency Identification, RFID tag, in 3D indoor space. The paper presents a new RFID based 3D Indoor Positioning System which shows performance improvement. The proposed positioning system combines two methods: the Scene Analysis technique and Artificial Neural Network. The results of both simulation using Log-Distance Path Loss Model and...
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Guided Wave Propagation in Detection of Partial Circumferential Debonding in Concrete Structures
PublicationThe following article presents results of investigating the damage detection in reinforced concrete beams with artificially introduced debonding between the rod and cover, using a non-destructive method based on elastic waves propagation. The primary aim of the research was to analyze the possible use of guided waves in partial circumferential debonding detection. Guided waves were excited and registered in reinforced concrete...
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Machine Learning and data mining tools applied for databases of low number of records
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Machine learning techniques combined with dose profiles indicate radiation response biomarkers
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Multivariate Features Extraction and Effective Decision Making Using Machine Learning Approaches
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Overcoming “Big Data” Barriers in Machine Learning Techniques for the Real-Life Applications
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Analyzing the Effectiveness of the Brain–Computer Interface for Task Discerning Based on Machine Learning
PublicationThe aim of the study is to compare electroencephalographic (EEG) signal feature extraction methods in the context of the effectiveness of the classification of brain activities. For classification, electroencephalographic signals were obtained using an EEG device from 17 subjects in three mental states (relaxation, excitation, and solving logical task). Blind source separation employing independent component analysis (ICA) was...
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The use of a two-phase Monte Carlo material model to reflect the dispersion of asphalt concrete fracture parameters
PublicationThe work covers comprehensive laboratory tests of semi-circular bending (SCB) of asphalt concrete samples. The results of two test series, including four and 32 SCB specimens, indicate a substantial scatter of force–deflection (F-d) histories. The numerical analysis is aimed to reflect the maximum breaking load and fracture energy of the samples, pointing out their random character. The original simulation-based fictitious Monte...
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Design of experiments approach for ultimate strength assessment of corroded stiffened plates
PublicationThe impact of corrosion degradation on the ultimate strength of stiffened plates subjected to compressive loading is investigated. The DoE technique is used considering different plate and column slenderness ratios and corrosion severity. The FE method, considering geometrical and material nonlinearities, is employed. A two-stage corrosion degradation model is adopted. Firstly, a uniform thickness loss is adopted to reflect the...
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Finite element analysis on failure of reinforced concrete corner in sewage tank under opening bending moment
PublicationW artykule omówiono mechanizm uszkodzenia żelbetowego zbiornika ściekowego w narożniku ściany, który uległ uszkodzeniu podczas próby wypełnienia na skutek nadmiernych przemieszczeń poziomych ścian pod wpływem otwierającego momentu zginającego. Aby wyjaśnić przyczyny awarii, przeprowadzono kompleksowe obliczenia metodą elementów skończonych (MES) żelbetowego zbiornika w warunkach odkształcenia płaskiego. Beton zamodelowano za pomocą...
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On some problems in determining tensile parameters of concrete model from size effect tests
PublicationThe paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law...
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Projekt Leonardo da Vinci EMDEL (European Model for Distance Education and Learning) - otwarte szkolenia online.
PublicationW referacie zaprezentowano główne zadania oraz ofertę szkoleniową Centrum Edukacji Niestacjonarnej Politechniki Gdańskiej (CEN PG) w kontekście realizowanych projektów Unii Europejskiej. Przedstawiono projekt Leonardo da Vinci EMDEL - European Model for Distance Education and learning - realizowany przez CEN PG w latach 2001-2005 oraz opisano doświadczenia w zakresie adaptacji i lokalizacji opracowanych przez partnerów projektu...
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Automatic strength assessment of the virtually modelled concrete interfaces based on shadow-light images
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The Effect of Texturing of the Surface of Concrete Substrate on the Pull-Off Strength of Epoxy Resin Coating
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Accuracy analysis of 3D model obtained by photogrammetric method on the example of historic room from Wisłoujście Fortress
PublicationThe article presents a comparison of obtained models of a test object. Close range photogrammetry was used to obtain 3D models. As test object was used one of the rooms located in Wisłoujście Fortress in Gdańsk, Poland. Different models were obtained by using different distribution and number of reference points. Article contains analysis of differences between coordinates of control points obtained from total station measurements...
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Limits of enhanced of macro- and meso-scale continuum models for studying size effect in concrete under tension
PublicationThe paper investigates a mechanical quasi-static size effect in concrete during splitting tension at the macro- and meso-level. In experiments, five different diameters of cylindrical concrete specimens were tested. Twodimensional plane strain finite element (FE) simulations were carried out to reproduce the experimental size effect. The size effect in experiments by Carmona et al. was also simulated. Two enhanced continuum concrete...
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Analytical model of torsional vibrations of typical sawing machine main drive system
PublicationPrzedstawiono model fizyczny i matematyczny drgań skrętnych napędu głównego typowej pilarki tarczowej. Model tworzą elementy sztywne SES połączone między sobą za pośrednictwem elementów sprężysto - tłumiących EST w układzie szeregowym. W modelu matematycznym uwzględniono: właściwości dynamiczne silnika napędowego, wymiary piły tarczowej, cechy materiału obrabianego (wymiary, rodzaj drewna, wilgotność drewna) oraz właściwości dynamiczne...
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Preparation, characterization, and manufacturing of new polymeric materials for 3D printing for medical applications
PublicationThis work concerns the synthesis, formation, and characteristics of new filaments for 3D printing in FDM™/FFF technology for medical purposes. Two types of filaments were developed, i.e. degradable polyurethane and biodegradable polylactide-starch. The influence of the 3D printing process on selected filament properties was investigated. A detailed analysis of the filament formation process by the extrusion method was carried out,...
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Lead-free bismuth-based perovskites coupled with g–C3N4: A machine learning based novel approach for visible light induced degradation of pollutants
PublicationThe use of metal halide perovskites in photocatalytic processes has been attempted because of their unique optical properties. In this work, for the first time, Pb-free Bi-based perovskites of the Cs3Bi2X9 type (X = Cl, Br, I, Cl/Br, Cl/I, Br/I) were synthesized and subjected to comprehensive morphological, structural, and surface analyses, and photocatalytic properties in the phenol degradation reaction were examined. Furthermore,...
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Experimental investigations of damage evolution in concrete during bending by continuous micro-CT scanning
PublicationThe paper describes experimental investigation results of fracture in notched concrete beams under quasi-static three-point bending. To visualize 3D fracture in concrete under bending, an extended X-ray micro-computed tomography system was used, i.e. the tomography system SkyScan 1173 was connected to the loading machine ISTRON 5569. This combined system enabled to shot images of deforming concrete beams during a continuous deformation...
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3D Machine Vision System for Inspection of Contact Strips in Railway Vehicle Current Collectors
PublicationConstruction and technical condition of current collectors is crucial to reliability and safety of railway transportation. According to the Technical Specifications for Interoperability railway vehicles in the European Union should be equipped with carbon contact strips. Excessive wear or defects of contact strips degrade the capability of undisturbed power transmission, cause faster wear of contact wire, and can even result in...
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Towards trustworthy multi‐modal motion prediction: Holistic evaluation and interpretability of outputs
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Magnetic field mapping along a NV-rich nanodiamond-doped fiber
PublicationIntegration of NV−-rich diamond with optical fibers enables guiding quantum information on the spin state of the NV− color center. Diamond-functionalized optical fiber sensors have been demonstrated with impressive sub-nanotesla magnetic field sensitivities over localized magnetic field sources, but their potential for distributed sensing remains unexplored. The volumetric incorporation of diamonds into the optical fiber core allows...