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Catalog Publications
Year 2024
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Revisiting Supervision for Continual Representation Learning
Publication"In the field of continual learning, models are designed to learn tasks one after the other. While most research has centered on supervised continual learning, there is a growing interest in unsupervised continual learning, which makes use of the vast amounts of unlabeled data. Recent studies have highlighted the strengths of unsupervised methods, particularly self-supervised learning, in providing robust representations. The improved...
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RF Input-Quasi-Reflectionless Dispersive-Delay Structures Based on Complementary-Diplexer Circuits
PublicationA class of RF dispersive-delay structures (DDSs) with input-quasi-reflectionless behavior is reported. It is based on the exploitation of complementary-diplexer circuit networks, in which the out-of-band RF-input-power echoes reflected by the main bandpass-filter-(BPF)-type channel are dissipated by the resistively-terminated auxiliary bandstop-filter-(BSF)-type channel. Specifically, it is shown that the influence of the absorptive...
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Robust local basis function algorithms for identification of time-varying FIR systems in impulsive noise environments
PublicationWhile local basis function (LBF) estimation algorithms, commonly used for identifying/tracking systems with time-varying parameters, demonstrate good performance under the assumption of normally distributed measurement noise, the estimation results may significantly deviate from satisfactory when the noise distribution is of impulsive nature, for example, heavy-tailed or corrupted by outliers. This paper introduces a computationally...
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Sampling-based novel heterogeneous multi-layer stacking ensemble method for telecom customer churn prediction
PublicationIn recent times, customer churn has become one of the most significant issues in business-oriented sectors with telecommunication being no exception. Maintaining current customers is particularly valuable due to the high degree of rivalry among telecommunication companies and the costs of acquiring new ones. The early prediction of churned customers may help telecommunication companies to identify the causes of churn and design...
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Schottky Junction-Driven Photocatalytic Effect in Boron-Doped Diamond-Graphene Core–Shell Nanoarchitectures: An sp3/sp2 Framework for Environmental Remediation
PublicationSelf-formation of boron-doped diamond (BDD)-multilayer graphene (MLG) core–shell nanowalls (BDGNWs) via microwave plasma-enhanced chemical vapor deposition is systematically investigated. Here, the incorporation of nitrogen brings out the origin of MLG shells encapsulating the diamond core, resulting in unique sp3/sp2 hybridized frameworks. The evolution mechanism of the nanowall-like morphology with the BDD-MLG core–shell composition...
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Segmentation-Based BI-RADS ensemble classification of breast tumours in ultrasound images
PublicationBackground: The development of computer-aided diagnosis systems in breast cancer imaging is exponential. Since 2016, 81 papers have described the automated segmentation of breast lesions in ultrasound images using arti- ficial intelligence. However, only two papers have dealt with complex BI-RADS classifications. Purpose: This study addresses the automatic classification of breast lesions into binary classes (benign vs. ma- lignant)...
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Self-assembled concentric stripes of diamond particles by a pinning-depinning mechanism
PublicationWe describe the novel mechanism of spontaneous formation of the concentric stripe patterns of microdiamonds via gradual solvent evaporation from a suspension confined in a teardrop well. The self-organized patterns exhibit a series of arcs with regular spacings varying between hundreds of micrometers and millimeters. They result from an interplay between the directional forced circulation of the solvent and a stick-slip movement...
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Semi-definite programming and quantum information
PublicationThis paper presents a comprehensive exploration of semi-definite programming (SDP) techniques within the context of quantum information. It examines the mathematical foundations of convex optimization, duality, and SDP formulations, providing a solid theoretical framework for addressing optimization challenges in quantum systems. By leveraging these tools, researchers and practitioners can characterize classical and quantum correlations,...
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Serum levels of stem cell factor for predicting embryo quality
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Session-Based Recommendation with Graph Neural Networks with an Examination of the Impact of Local and Global Vectors
PublicationThis study investigates the application of graph neural networks (GNN) in session-based recommendation systems (SR), focusing on a key modification involving the use of a global vector. Session-based recommendation systems often face challenges in accurately capturing user behavior due to the limited data available within individual sessions. The SR-GNN model, originally designed for automatic feature extraction from session graphs...
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Shallow Water Communication with an Object Buried in Bottom Sediments
PublicationUnderwater acoustic communications (UAC) in shallow water applications is a very difficult task. This task becomes even more difficult when there is a need to ensure reliable communication with an object buried in bottom sediments. The article presents a simulation of an acoustic transmission channel in conditions of strong multi-path propagation to an object buried in bottom sediments. The impulse response method was used, supported...
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Shallow-Water Acoustic Communications in Strong Multipath Propagation Conditions
PublicationA phenomenon that has a strong impact on signal transmission conditions in Underwater Acoustic Communication (UAC) systems is multipath propagation. As a result of multipath propagation, the transmitted signal undergoes time dispersion which results in inter-symbol interference observed on the receiving side. Time dispersion is large, especially in horizontal channels in shallow waters which significantly limits the transmission...
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Sign Language Recognition Using Convolution Neural Networks
PublicationThe objective of this work was to provide an app that can automatically recognize hand gestures from the American Sign Language (ASL) on mobile devices. The app employs a model based on Convolutional Neural Network (CNN) for gesture classification. Various CNN architectures and optimization strategies suitable for devices with limited resources were examined. InceptionV3 and VGG-19 models exhibited negligibly higher accuracy than...
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Simple Measurement Method for Resistive Sensors Based on ADCs of Microcontrollers
PublicationA new, complete measurement method for resistance measurement of resistive sensors for systems based on microcontrollers equipped with analog-to-digital converters (ADCs) is proposed. The interface circuit consists of only four resistors, including a resistive sensor and a reference resistor, connected directly to the microcontroller pins. It is activated only during measurements, which significantly reduces power consumption....
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Simulation Model for Application of the SDN Concept in IMS/NGN Network Transport Stratum
PublicationThe paper presents a simulation model allowing examination of cooperation between two currently used telecommunication networks concepts: IP Multimedia Subsystem/Next Generation Network (IMS/NGN) and Software-Defined Networking (SDN). Application of the SDN architecture elements in IMS/NGN networks will enable unified control and management of transport resources for various transport technologies and equipment manufacturers. However,...
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Single-Chip Versatile Signal Generator for Navigation
PublicationThe emergence of Global Navigation Satellite Systems (GNSS) has revolutionized the way we perceive and utilize positioning, navigation, and timing (PNT) services across various sectors, including aviation, maritime, military, and consumer electronics. The development and deployment of GNSS signal generators are crucial for the testing, validation, and integration of GNSS-based technologies. This paper introduces a groundbreaking...
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Sleep alterations in treatment-resistant depression patients undergoing ketamine treatment
PublicationBackground This study examines self-reported sleep alterations in treatment-resistant depression (TRD) inpatients following intravenous ketamine administration. Methods This is a post-hoc analysis of a naturalistic observational study, which enrolled 28 inpatients with treatment-resistant major depressive disorder and analyzed self-reported sleep changes (items 1–4; ‘insomnia’, ‘nighttime restlessness’, ‘early morning waking’,...
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Smooth least absolute deviation estimators for outlier-proof identification
PublicationThe paper proposes to identify the parameters of linear dynamic models based on the original implementation of least absolute deviation estimators. It is known that the object estimation procedures synthesized in the sense of the least sum of absolute prediction errors are particularly resistant to occasional outliers and gaps in the analyzed system data series, while the classical least squares procedure unfortunately becomes...
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Software Architecture Design of ASV Rybitwa: Development of an Autonomous Surface Vehicle for Dynamic Navigation and Task Execution
PublicationThis paper introduces the software design of an Autonomous Surface Vehicle (ASV) named ASV Rybitwa. It was designed as an easily transportable platform capable of autonomous navigation and performing tasks during the RoboBoat 2024 competition, with emphasis on its modularity, generality and extendibility. The paper presents a software architecture for a small autonomous surface vehicle using novel tools that provide easy system...
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Sounding Mechanism of a Flue Organ Pipe—A Multi-Sensor Measurement Approach
PublicationThis work presents an approach that integrates the results of measuring, analyzing, and modeling air flow phenomena driven by pressurized air in a flue organ pipe. The investigation concerns a Bourdon organ pipe. Measurements are performed in an anechoic chamber using the Cartesian robot equipped with a 3D acoustic vector sensor (AVS) that acquires both acoustic pressure and air particle velocity. Also, a high-speed camera is employed...
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sp2-rich dendrite-like carbon nanowalls as effective electrode for environmental monitoring of explosive nitroaromatic
PublicationNitroaromatic compounds are commonly used explosive materials that pose a risk to human health and ecosystems due to their acute toxicity and carcinogenicity. Nitroaromatics have numerous pathways into the environment via discarded munitions (e.g. into the Baltic Sea after World War II), after use in mining operations, and in industrial run-off from factories producing these compounds (which are produced across the world to date)....
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Specification-Oriented Automatic Design of Topologically Agnostic Antenna Structure
PublicationDesign of antennas for modern applications is a challenging task that combines cognition-driven development of topology intertwined with tuning of its parameters using rigorous numerical optimization. However, the process can be streamlined by neglecting the engineering insight in favor of automatic de-termination of structure geometry. In this work, a specification-oriented design of topologically agnostic antenna is considered....
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Sport-related concussion alters cerebral hemodynamic activity during controlled respiration
PublicationThis study investigated cerebral hemodynamic activity following sport-related concussion. Prefrontal cortex oxygenation was assessed by near-infrared spectroscopy (NIRS) during a controlled breathing protocol. Wavelet transformation of the NIRS signals showed significant decreases in HbO2 and HbD amplitude at the respiratory frequency interval (0.10–0.6 HZ) from preseason baseline to acute concussion. These results suggest a decreased...
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Statistical Data Pre-Processing and Time Series Incorporation for High-Efficacy Calibration of Low-Cost NO2 Sensor Using Machine Learning
PublicationAir pollution stands as a significant modern-day challenge impacting life quality, the environment, and the economy. It comprises various pollutants like gases, particulate matter, biological molecules, and more, stemming from sources such as vehicle emissions, industrial operations, agriculture, and natural events. Nitrogen dioxide (NO2), among these harmful gases, is notably prevalent in densely populated urban regions. Given...
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Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublicationThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
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Subjective quality evaluation of 8- and 10-bit MP4-coded video sequences from Netflix
PublicationRecently, many researchers have been intensively conducting quality of service (QoS), quality of experience (QoE), and user experience (UX) studies in the field of video analysis. This paper is intended to make a new, complementary contribution to this field. Currently, streaming platforms are key products in relation to delivering video content online. Most often, they include the MP4 video format, which is most widely utilized...
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Substrate Integrated Waveguide-Based Frequency-Tunable Self-Octaplexing Antenna
PublicationThis communication presents the first-ever substrate integrated waveguide (SIW)-based frequency-tunable self-octaplexing antenna (SOA) for wireless communication. The structure is arranged by implementing eight distinct patches with planar 50-ohm feedlines at the top of the SIW cavity, which realize eight distinct resonant frequencies. Independent tuning of each resonant frequency is achieved by incorporating appropriately allocated...
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Substrate Integrated Waveguide-Based Ultra-Compact Self-Heptaplexing Antenna for IoT Connectivity
PublicationThis paper introduces an innovative design of a substrate-integrated waveguide (SIW)-based self-heptaplexing antenna (SHA). The proposed structure is implemented using a combination of circular and rectangular HM-SIW cavities. Furthermore, the antenna contains seven individual patches on top of the SIW cavity to operate at seven distinct frequencies. The microstrip feeding technique has been used to activate seven distinct ports....
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Suitability of acoustic power amplifiers as power amplifiers in underwater communication systems
PublicationThe paper presents selected acoustic power amplifiers from among those currently available. The results of a series of measurements characterising the amplifiers are presented. The measured amplitude and phase characteristics as a function of frequency for four selected amplifiers are analysed. The spectra of the output signal in the band from 4 kHz to 30 kHz are presented. The usefulness of the selected amplifiers in an underwater...
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Suspension and process parameters selection for electrophoretic deposition of Mn–Co spinel coating on steel interconnects
PublicationMetallic interconnect coatings, consisting of MnCo2O4 spinel, were effectively applied to Crofer 22 APU using the electrophoretic deposition (EPD) method in both H2O: ethanol and pure ethanol solvents. The primary goal of this method was to prevent chromium migration, minimize evaporation, and control the oxidation rate. The study aimed to assess the quality, adhesion, and thickness of the Mn–Co coating, with the objective of...
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System wizyjny dla robota łapiącego piłki
PublicationW niniejszej pracy zaproponowano i przetestowano system wizyjny służący śledzeniu lecącej piłki w celu wypracowania sterowania dla robota wieloosiowego mającego za zadanie złapanie jej. Do detekcji i lokalizacji piłki na obrazie z dwóch, prostopadle ustawionych, kamer zastosowano laplasjan filtru gaussowskiego (LoG) oraz autorski podsystem filtracji rozmytej. Estymację trajektorii lecącej piłki w przestrzeni wykonano w oparciu...
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Tailoring Defects in B, N-Codoped Carbon Nanowalls for Direct Electrochemical Oxidation of Glyphosate and its Metabolites
PublicationTailoring the defects in graphene and its related carbon allotropes has great potential to exploit their enhanced electrochemical properties for energy applications, environmental remediation, and sensing. Vertical graphene, also known as carbon nanowalls (CNWs), exhibits a large surface area, enhanced charge transfer capability, and high defect density, making it suitable for a wide range of emerging applications. However, precise...
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Task-recency bias strikes back: Adapting covariances in Exemplar-Free Class Incremental Learning
PublicationExemplar-Free Class Incremental Learning (EFCIL) tackles the problem of training a model on a sequence of tasks without access to past data. Existing state-of-the-art methods represent classes as Gaussian distributions in the feature extractor's latent space, enabling Bayes classification or training the classifier by replaying pseudo features. However, we identify two critical issues that compromise their efficacy when the feature...
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Teaching High–performance Computing Systems – A Case Study with Parallel Programming APIs: MPI, OpenMP and CUDA
PublicationHigh performance computing (HPC) education has become essential in recent years, especially that parallel computing on high performance computing systems enables modern machine learning models to grow in scale. This significant increase in the computational power of modern supercomputers relies on a large number of cores in modern CPUs and GPUs. As a consequence, parallel program development based on parallel thinking has become...
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Team research project – evolution from faculty activity to university study standard
PublicationThe article will describe the idea of a university-wide team student project as a tool of modern academic teaching in the era of widespread use of artificial intelligence tools. The problem of contemporary teaching is the emerging tools for automatic content generation, including didactic and scientific content. The question arises how to verify students' qualifications and learning outcomes. The solution may be students' group...
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Teoria grafów wczoraj i dziś
PublicationW pracy naszkicowano kamienie milowe teorii grafów poczynając od pierwszego artykułu Eulera na temat mostów w Królewcu z połowy 18. wieku. Następnie opisano słynny problem 4 barw i jego wariacje. Pracę kończy charakterystyka najnowszych wyzwań teorii grafów.
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Terahertz Dual-Band Metamaterial Biosensor for Cervical-Cancer Diagnostics
PublicationThis study highlights the potential of employing terahertz metamaterial structures as dual-band biosensors for the early detection of cancerous biological tissue. The fundamental principle leveraged here is the alteration of the effective dielectric constant of biological tissue by cancerous cells. The change in the dielectric constant, in turn, induces a shift in the resonance frequency of the metamaterial sensor. One notable...
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The Application of a Mobile Unmanned Device for Monitoring Water and Sediment Pollution in the Port of Gdynia
PublicationPollution in the Port of Gdynia can encompass various types of substances and contaminants that affect the quality of water and sediment in this region. Ships entering and leaving the port can release pollutants such as oil, fuel, waste, and chemicals into the water. Controlling and monitoring these pollutants is a crucial part of environmental stewardship. In recent years, uncrewed units have been increasingly in use for in situ...
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The Big Book of online education for academics and other teaching professionals
PublicationThe Big Book of Online Education to unikatowa, bogata w multimedia publikacja, napisana przez międzynarodowy zespół autorów – ekspertów w dziedzinie metodyki, nowoczesnej edukacji i e-learningu. Znajdziemy w niej mnóstwo porad, inspiracji i informacji o narzędziach użytecznych w dydaktyce, oraz przykładów zastosowania innowacyjnych metod i technik w praktyce akademickiej. Jest to najbogatsza tego typu pozycja na rynku poradników...
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The Drawing Paradigm between Representation and Interaction with Virtual Image
PublicationTraditional drawing involves drawing on some surface, often a plane, e.g. a sheet of paper, a school board or a wall. This type of drawing therefore takes place in two dimensions of this surface. Transferring this activity to a computer, or rather to the surface of its screen, did not change the two-dimensional nature of this action. Practically all applications today, from Paint to sophisticated computer-aided design tools, still...
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The effect of groyne field on trapping macroplastic. Preliminary results from laboratory experiments
PublicationMacroplastic, a precursor of microplastic pollution, has become a new scope of research interest. However, the physical processes of macroplastic transport and deposition in rivers are poorly understood, which makes the decisions of where to locate macroplastic trapping infrastructure difficult. In this research, we conducted a series of experiments in a laboratory channel, exploring the impact of groynes and flexible artificial...
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The Fuzzy Analysis of Western Windfarm Transportation Safety
PublicationThe previously completed route planning research of Navigational Transportation Safety in the Taiwan Western wind farm analyzed delves into the expansion of sustainable wind energy and navigation safety together along the Taiwan Western for confronting the challenge of balancing resource coexistence and displacement. Previous studies primarily focused on route planning and vessel traffic density which developed the necessary comprehensive...
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The Greencoin project. A guideline for the implementation strategy
PublicationReport of the Greencoin project identification and implementation strategy, preliminary study, project results, implementation guidelines directed to the European city representatives, educators, urban activists.
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The Impact of Foreign Accents on the Performance of Whisper Family Models Using Medical Speech in Polish
PublicationThe article presents preliminary experiments investigating the impact of accent on the performance of the Whisper automatic speech recognition (ASR) system, specifically for the Polish language and medical data. The literature review revealed a scarcity of studies on the influence of accents on speech recognition systems in Polish, especially concerning medical terminology. The experiments involved voice cloning of selected individuals...
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The KLC Cultures Synergy for Organizational Agility. Trust, Risk-Taking Attitude, and Critical Thinking as Moderators
PublicationOrganizational agility is visible in organizational change adaptability, and it is based on the development of dynamic capabilities, strategic sensitivity of leaders, accuracy and timing of decision-making, learning aptitude, flexibility in thinking and acting, and smooth resource flow across organizations, including the knowledge resource. In such a context, this study aimed to expose how the knowledge, learning, and collaboration...
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Theoretical modelling of efficient fire safety water networks by certified domination
PublicationThis paper explores a new way of designing water supply networks for fire safety using ideas from graph theory, focusing on a method called certified domination. Ensuring a good water supply is crucial for fire safety in communities, this study looks at the rules and problems in Poland for how much water is needed to fight fires in different areas and how this can be achieved at a lowest possible cost. We present a way to plan...
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Three modes of electrochemical impedance spectroscopy measurements performed on vanadium redox flow battery
PublicationThis article presents an innovative approach to monitor working redox flow batteries using dynamic electrochemical impedance spectroscopy, diverging from the commonly sequential impedance methods carried out under potentiostatic or galvanostatic conditions close to the open circle voltage. The authors introduce a fresh variation of dynamic impedance measurement that leverages an amplitude-modulated multi-frequency alternating current...
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Three-component NiO/Fe3O4/rGO nanostructure as an electrode material towards supercapacitor and alcohol electrooxidation
PublicationA nanocomposite made of nickel oxide and iron oxide (NiO/Fe3O4) and its hybrid with reduced graphene oxide (rGO) as a conductive substrate with a highly functional surface (NiO/Fe3O4/rGO) was synthesized using a simple hydrothermal approach. This study addresses the challenge of developing efficient materials for energy storage and alcohol fuel cells. After confirming the synthesis through structural analysis, the potential of...
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Toward Sustainable Development: Exploring the Value and Benefits of Digital Twins
PublicationThe complexity and number of data streams generated by internal processes exceed the capabilities of most current simulation environments. Consequently, there is a need for the development of more advanced solutions that can handle any number of simultaneous simulations. One of the most promising ideas to address these and other challenges is the concept of a Digital Twin (DT), which refers to a digital representation or a virtual...
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Towards Universal Visualisation of Emotional States for Information Systems
PublicationThe paper concerns affective information systems that represent and visualize human emotional states. The goal of the study was to find typical representations of discrete and dimensional emotion models in terms of color, size, speed, shape, and animation type. A total of 419 participants were asked about their preferences for emotion visualization. We found that color, speed, and size correlated with selected discrete emotion...