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Search results for: INPUT ANGLE DISPLACEMENT
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Akaike's final prediction error criterion revisited
PublicationWhen local identification of a nonstationary ARX system is carried out, two important decisions must be taken. First, one should decide upon the number of estimated parameters, i.e., on the model order. Second, one should choose the appropriate estimation bandwidth, related to the (effective) number of input-output data samples that will be used for identification/ tracking purposes. Failure to make the right decisions results...
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Examining Classifiers Applied to Static Hand Gesture Recognition in Novel Sound Mixing System
PublicationThe main objective of the chapter is to present the methodology and results of examining various classifiers (Nearest Neighbor-like algorithm with non-nested generalization (NNge), Naive Bayes, C4.5 (J48), Random Tree, Random Forests, Artificial Neural Networks (Multilayer Perceptron), Support Vector Machine (SVM) used for static gesture recognition. A problem of effective gesture recognition is outlined in the context of the system...
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Using an IEEE1149.1 Test Bus for Fault Diagnosis of Analog Parts of Electronic Embedded Systems
PublicationThe new solution of a BIST called the JTAG BIST for self-testing of analog parts of electronic embedded systems is presented in the paper. The JTAG BIST consists of the BCT8244A and SCANSTA476 integrated circuits of Texas Instruments controlled via the IEEE 1149.1 bus. The BCT8244A is a scan test device with octal buffers, and the SCANSTA476 is a 12-bit ADC with 8 analog input channels. Self-testing approach is based on the fault...
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Optimization of Execution Time under Power Consumption Constraints in a Heterogeneous Parallel System with GPUs and CPUs
PublicationThe paper proposes an approach for parallelization of computations across a collection of clusters with heterogeneous nodes with both GPUs and CPUs. The proposed system partitions input data into chunks and assigns to par- ticular devices for processing using OpenCL kernels defined by the user. The sys- tem is able to minimize the execution time of the application while maintaining the power consumption of the utilized GPUs and...
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Ionosphere variability II: Advances in theory and modeling
PublicationThis paper aims to provide an overview on recent advances in ionospheric modeling capabilities, with the emphasis in the efforts relevant to electron density variability. The discussion spans a wide range of model formulations (e.g., from purely empirical to physics-based ones and data-driven approaches) seeking for advances or gaps with regard to present challenges. This discussion is further supported by consideration of the...
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Benchmarking overlapping communication and computations with multiple streams for modern GPUs
PublicationThe paper presents benchmarking a multi-stream application processing a set of input data arrays. Tests have been performed and execution times measured for various numbers of streams and various compute intensities measured as the ratio of kernel compute time and data transfer time. As such, the application and benchmarking is representative of frequently used operations such as vector weighted sum, matrix multiplication etc....
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Machine Learning Applied to Aspirated and Non-Aspirated Allophone Classification—An Approach Based on Audio "Fingerprinting"
PublicationThe purpose of this study is to involve both Convolutional Neural Networks and a typical learning algorithm in the allophone classification process. A list of words including aspirated and non-aspirated allophones pronounced by native and non-native English speakers is recorded and then edited and analyzed. Allophones extracted from English speakers’ recordings are presented in the form of two-dimensional spectrogram images and...
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Global value chains and labour markets – simultaneous analysis of wages and employment
PublicationThis study examines the overall effect of global value chains (GVCs) on wages and labour demand. It exploits the World Input–Output Database to measure GVC involvement via recently developed participation indices (using both backward and forward linkages) and the relative GVC position using three-stage least squares regression. We find that the relative GVC position is negatively correlated with wages and employment and that the...
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Solid-State Modification of Poly(butylene terephthalate) with a Bio-Based Fatty Acid Dimer Diol Furnishing Copolyesters with Unique Morphologies
PublicationCopolyesters based on poly(butylene terephthalate) (PBT) and a bio-based fatty acid dimer diol (FADD) were prepared by solid-state modification (SSM). The chemical incorporation of the FADD into the backbone of the PBT was proven using various techniques. It was clear that the incorporation rate was diffusion-limited rather than reaction-limited. From quantitative 13C NMR a nonrandom chemical microstructure was obtained at all...
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Nowe zakresy kreowania wizerunku fasad przy zastosowaniu technologii filtrów optycznych.
PublicationModern facades, whether made of glass or including transparent, translucent or reflective elements, let through a particular light spectrum or change its intensity in many different ways. “Filtering facades” may change the image seen through them or change the colour of passing light according to specific circumstances: the angle of observation or temperature. These indicated properties of facades acting as “filters” were made...
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Application of fracture mechanics for energetic effects predictions while wood sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (power) could be considered from a point of view of modern fracture mechanics. Cutting forces may be employed to determine not only toughness...
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The Effect of Welding Conditions on Diffusible Hydrogen Content in Deposited Metal
PublicationThe article presents the results of a literature survey and preliminary tests which set out effects of welding conditions on the amount of diffusible hydrogen in deposited metal. Experiments were conducted by using rutile coated electrodes which generate high contents of diffusible hydrogen in deposited metal. The amount of diffusible hydrogen was determined by a glycerin test.Eleven factors were considered: the electrode angle,...
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THE EFFECT OF ALTERNATIVE CUTTER PATHS ON FLATNESS DEVIATIONS IN THE FACE MILLING OF ALUMINUM PLATE PARTS
PublicationIn this paper the relationships between the alternative machining paths and flatness deviations of the aluminum plate part, were presented. The flatness tolerance of the main surface of the plate part has crucial meaning due to the assembly requirement of piezoelectric elements on the radiator. The aluminum bodies under investigation are the base part of the radiators with crimped feathers for the train industry. The surface of...
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Estimation of fracture toughness and shear yield stress of orthotropic materials in cutting with rotating tools
PublicationThe cutting force is an energetic effect of splitting material, and might be considered from a point of view of modern fracture mechanics. Forecasting of the shear plane angle in cutting broaden possibilities for modelling of the cutting process even for thin uncut chips. Such mathematical model has been developed here for description of the orthotropic materials’ cutting on the base of fracture theory, and includes work of separation...
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Optimal shape design of multi-element trawl-doors using local surrogate models
PublicationTrawl-doors have a large influence on the fuel consumption of fishing vessels. Design and optimiza-tion of trawl-doors using computational models are a key factor in minimizing the fuel consump-tion. This paper presents an optimization algorithm for the shape design of trawl-door shapes using computational fluid dynamic (CFD) models. Accurate CFD models are computationally expensive. Therefore, the direct use of traditional optimization...
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Influence of Two-Stage Anodization on Properties of the Oxide Coatings on the Ti–13Nb–13Zr Alloy
PublicationThe increasing demand for titanium and its alloys used for implants results in need of such innovative surface treatment that may jointly increase corrosion resistance and biocompatibility, and demonstrate antibacterial protection at no cytotoxicity. The purpose of this research was to characterize the effect of two-stage anodization, performed for 30 min in phosphoric acid, at the presence of hydrofluoric acid in the second stage....
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Influence of friction stir welding technological parameters on the properties of the joints of selected aluminum alloys
PublicationThe purpose of this dissertation was to determine the effect of friction stir welding technological parameters on the properties of selected aluminum alloy joints, with consideration of the residual stresses and dislocation density in the joints. The goal of the present work was also to produce defect-free joints with high mechanical and electrochemical properties. In the dissertation, similar welds of AA6082 alloy and dissimilar...
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Theoretical Design of the Molecular Structure of Bent-Core Mesogens with Large Second-Order Nonlinear Optical Properties
PublicationABSTRACT: The first hyperpolarizability of two series of moleculeswith bent-shaped structures has been calculated at the ab initio level.The two series consist of carboxyl derivatives for which somemolecules are known to exhibit banana phases and of their sulfinatehomologues that have not been synthesized yet. The final purpose isto reveal the relevance or not in synthesizing these latter molecules.The strategy is based on reporting...
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60 GHz Microstrip Van Atta Arrays for Millimeter Wave Identification and Localization
PublicationIn this paper performance comparison of co-polarized and cross-polarized microstrip Van Atta arrays working in the 60 GHz frequency range is presented. They can be treated as simple chipless RFID tags with frequency response based identification. Tags with three different nominal resonance frequencies of 57, 62 and 67 GHz are designed by scaling optimized base model. Designed 62 GHz co-polarized and cross-polarized arrays with...
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Influence of Natural Conditions on the Imaging of the Bottom of the Gdańsk Bay by Means of the Side Scan Sonar
PublicationThe interest in underwater resources is the reason for the development of modern hydroacoustic systems, including side sonars, which find numerous applications such as: research of seabed morphology and sediment characteristics, preparation of sea sediment maps, and even in special cases of biocenoses such as sea grass meadows, detection of specific targets at the bottom such as shipwrecks, mines, identification of suitable sites...
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The effect of beech wood (Fagus sylvatica L.) steaming process on the colour change versus depth of tested wood layer
PublicationThe results of experimental research on the colour changes of beech wood at different depths of the tested layer are presented. Beech wood (Fagus sylvatica L.) dried in a conventional kiln was tested. Half of the wood samples were steamed prior to the drying process. Colour changes were measured at various depths after the face milling process was used to remove the material to expose to the deeper surface. The colour changes were...
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Thin-walled frames and grids - statics and dynamics
PublicationFrames and grids assembled with thin-walled beams of open cross-section are widely applied in various civil engineering and vehicle or machine structures. Static and dynamic analysis of theses structures may be carried out by means of different models, startingfrom the classical models made of beam elements undergoing the Kirchhoff assumptions to the FE discretization of whole frame into plane elements. The former model is very...
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Developing Methodology for Model Tests of Floating Platforms in Low -Depth Towing Tank
PublicationThe paper presents two different methods of physical modeling of semi-submersible platform mooring system for research in low depth towing tank. The tested model was made in the scale of 1:100 resembling the "Thunder Horse" platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced starshape and attached at the bottom to suction piles. The tests...
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Incorporation of nitrogen in diamond films - A new way of tuning parameters for optical passive elements
PublicationThis paper investigates the impact of nitrogen incorporation in diamond films for the construction of an interferometric sensor to measure displacement. Diamond films with different nitrogen levels (0–5%) were deposited on silicon substrates by microwave plasma enhanced chemical vapor deposition. The structural characteristics of these samples are characterized using scanning electron microscopy (SEM), atomic force microscopy...
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On local buckling of cold-formed channel members
PublicationThe paper deals with local buckling of the compressed flanges of cold-formed thin-walled channel beams subjected to pure bending or axially compressed columns. Arbitrarily shaped flanges of open cross-sections and the web-flange interactions are taken into account. Buckling deformation of a beam flange is described by displacement related to torsion of the flange about the line of its connection with the web. Total potential energy...
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Non-standard contact conditions in generalized continua: microblock contact model for a Cosserat body
PublicationGeneralized continuum theories involve non-standard boundary conditions that are associated with the additional kinematic variables introduced in those theories, e.g., higher gradients of the displacement field or additional kinematic degrees of freedom. Accordingly, formulation of a contact problem for such a continuum necessarily requires that adequate contact conditions are formulated for the additional kinematic variables and/or...
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A general isogeometric finite element formulation for rotation‐free shells with in‐plane bending of embedded fibers
PublicationThis article presents a general, nonlinear isogeometric finite element formulation for rotation-free shells with embedded fibers that captures anisotropy in stretching, shearing, twisting, and bending - both in-plane and out-of-plane. These capabilities allow for the simulation of large sheets of heterogeneous and fibrous materials either with or without matrix, such as textiles, composites, and pantographic structures. The work...
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Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation
PublicationThe presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical...
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Vibro piles performance prediction using result of CPT
PublicationVibro piles belong to the group of full displacement piles with an expanded base, characterised by a very high load capacity, especially in non-cohesive soils. The problem is to adopt a reliable method for the determination of full load–settlement (Q–s) curve. A frequent difficulty is the determination of the load capacity limit based on the static load test because the course of the load–settlement curve is of a linear nature....
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Application of polymer element in reduction of temporary steel grandstand vibrations
PublicationThe numerical analysis focused on reduction of vibrations of a temporary steel scaffolding grandstand has been conducted in this paper. These types of structures are regularly subjected to dynamic loads which, in conjunction with light and quite slender structural members, may induce dangerous vibrations. To increase their safety, temporary steel grandstands are usually strengthened with the diagonal stiffeners of tubular cross...
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Increasing the Seismic Resistance of Wood-frame Buildings by Applying PU Foam as Thermal Insulation
PublicationWood-frame buildings are very common in regions that are exposed to earthquakes. Most of residential buildings are constructed using this technology; therefore, the seismic resistance of them is really essential in order to prevent human losses and structural damage. The aim of the present article is to show the results of the detailed numerical FEM analysis focused on the seismic behaviour of the wood-frame house with different...
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EXPERIMENTAL AND NUMERICAL INVESTIGATION ON SPECIMEN GEOMETRY EFFECT ON THE CTOD VALUE FOR VL-E36 SHIPBUILDING STEEL
PublicationThere are special cases in the marine industry, where additional material tests, such as the fracture toughness test, must be performed. Additional fracture toughness tests, such as CTOD (Crack Tip Opening Displacement), are typically performed on three-point bend specimens. The dimension that defines all the specimen dimensions is the thickness of the material to be tested. It is recommended by classification societies (e.g. DNVGL)...
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An Improved Method of Minimizing Tool Vibration during Boring Holes in Large-Size Structures
PublicationThe paper presents a thoroughly modified method of solving the problem of vibration suppression when boring large-diameter holes in large-size workpieces. A new approach of adjusting the rotational speed of a boring tool is proposed which concerns the selection of the spindle speed in accordance with the results of the simulation of the cutting process. This streamlined method focuses on phenomenological aspects and involves the...
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Experimental Investigations of Fracture Process Using DIC in Plain and Reinforced Concrete Beams under Bending
PublicationThe fracture behaviour of concrete and reinforced concrete beams under quasi-static three-point bending was comprehensively investigated with experiments at laboratory scale. The eight various concrete mixes were tested. The influence of the shape, volume and size of aggregate particles and reinforcement on concrete fracture under bending was studied. Displacements on the surface of concrete beams were measured by means of the...
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STANY NIEUSTALONE TOWARZYSZĄCE POMIAROWI IMPEDANCJI PĘTLI ZWARCIA W OBWODACH WYJŚCIOWYCH ZASILACZY BEZPRZERWOWYCH UPS
PublicationW pracy przedstawiono metodykę i wyniki pomiarów stanów nieustalonych w zasilaczu bezprzerwowym (UPS) typu on - line. Do rejestracji zdarzeń po stronie zasilania i na wyjściu UPS wykorzystano dwa przyrządy do pomiaru jakości energii elektrycznej zsynchronizowane czasowo. Rejestratory kompresują uzyskane dane pomiarowe, co może wprowadzać dodatkowe błędy pomiaru wielkości mierzonych – napięć i prądów. Dodatkowe rejestracje oscyloskopem...
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Bulk linearized CMOS differential pair transconductor for continuous-time OTA-C filter design
PublicationIn this paper, the MOS differential pair driven simultaneously from gates and bulk terminals is described. An approximated analytical solution of the voltage to current transfer function has been found for the proposed circuit. Four possible combinations of gate and bulk connections of the input signal are presented. Basing on the configuration giving the best linearity, the operational transconductance amplifier (OTA) has been designed...
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Applying Web 2.0 Concepts to Creating Energy Planning Portal
PublicationCommunity authorities in Europe are tasked to create Advanced Local Energy Plans (ALEP), which encompasses collecting local data on current energy use and generation, as well as generating future development scenarios. Both the data and the development scenarios must be publicly accessible as a basis for energy-related decisions taken by residents, local companies and other local institutions. The data must partially be collected...
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Stochastic resonance in measurements
PublicationNoise is usually associated with the negative phenomenon, hampering the measurements data and their analysis. This view has been broken in the '80s when the phenomenon of stochastic resonance (Stochastic Resonance - SR) was discovered. It is a phenomenon that occurs in nonlinear dynamic measurement systems when the selected input noise can optimize system performance. SR became a way to improve efficiency of weak signals detection....
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Towards the boundary between easy and hard control problems in multicast Clos networks
PublicationIn this article we study 3-stage Clos networks with multicast calls in general and 2-cast calls, in particular. We investigate various sizes of input and output switches and discuss some routing problems involved in blocking states. To express our results in a formal way we introduce a model of hypergraph edge-coloring. A new class of bipartite hypergraphs corresponding to Clos networks is studied. We identify some polynomially...
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Ontology management in the multi-agent system for the it evaluation
PublicationThe team of researchers at the Gdańsk University of Technology is currently developing a model of the multi-agent system (MAS_IT) that would aid the IT managers to find the most appropriate technology to the goals assumed. The knowledge is to be provided by experts and stored in the facts and rules bases. The responsibility of the verification process-on the input and query stages-is given to the ontology, making it to some extend...
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Multi-objective weather routing of sailboats considering wave resistance
PublicationThe article presents a method to determine the route of a sailing vessel with the aid of deterministic algorithms. The method assumes that the area in which the route is to be determined is limited and the basic input data comprise the wind vector and the speed characteristic of the vessel. Compared to previous works of the authors, the present article additionally takes into account the effect of sea waves with the resultant resistance...
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Modelling of Mechanical Behaviour of High-Frequency Piezoelectric Actuators Using Bouc-Wen Model
PublicationThe paper presents the application of a modified, symmetrical Bouc-Wen model to simulate a mechanical behaviour of high-frequency piezoelectric actuators (PAs). In order to identify parameters of the model, a two-step algorithm was utilized. In the first stage, the mechanical parameters were identified by taking into account their bilinear variability and using a square input voltage waveform. In the second step, the hysteresis...
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Organic matter removal efficiency in treatment wetlands simulation by COD fractions
PublicationThe objective of this paper was to investigate the organic fraction (colloidal, particulate, and dissolved) in sewage treatment in treatment wetland. Performance of TWs was simulated well with a simple first order model k – C* based on monitoring data. In this investigation background or residual concentration (C*) was assumed to be equal concentration of input influent organic matter in particulate (CODp). Calculated reaction...
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Ionosphere variability I: Advances in observational, monitoring and detection capabilities
PublicationThe paper aims to review recent advances regarding the observational and monitoring capabilities of the ionization conditions in the Earth's upper atmosphere. The analysis spans both ground and space-based experiments, seeking for new installations and/or missions, new or upgraded instrumentation and/or observational network establishments as means for advancing current understanding and prediction ability of the ionosphere variability....
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Unity-Gain Zero-Offset CMOS Buffer with Improved Feedforward Path
PublicationA voltage unity-gain zero-offset CMOS amplifier with reduced gain error and increased PSRR (power supply rejection ratio) is proposed. The amplifier uses two feed mechanisms, negative feedback and supporting positive feedforward, to achieve low deviation from unit gain over the entire input range. The circuit, designed in a standard 180-nanometer 1.8-voltage CMOS process, is compared with two known buffers of similar topology,...
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Real‐Time PPG Signal Conditioning with Long Short‐Term Memory (LSTM) Network for Wearable Devices
PublicationThis paper presents an algorithm for real‐time detection of the heart rate measured on a person’s wrist using a wearable device with a photoplethysmographic (PPG) sensor and accelerometer. The proposed algorithm consists of an appropriately trained LSTM network and the Time‐Domain Heart Rate (TDHR) algorithm for peak detection in the PPG waveform. The Long Short‐Term Memory (LSTM) network uses the signals from the accelerometer...
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EMI mitigation of GaN power inverter leg by local shielding techniques
PublicationThis paper presents local shielding techniques applied to a half-bridge inverter leg with the aim to reduce the common mode (CM) current noise at converter’s DC input. The research study is conducted for 650V Enhancement mode Gallium Nitride (GaN) power transistor switches. Main contributors of parasitic capacitances referred to the inverter-leg middle point node are identified. Then, shielding solutions are proposed to reduce...
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Limitations of Emotion Recognition in Software User Experience Evaluation Context
PublicationThis paper concerns how an affective-behavioural- cognitive approach applies to the evaluation of the software user experience. Although it may seem that affect recognition solutions are accurate in determining the user experience, there are several challenges in practice. This paper aims to explore the limitations of the automatic affect recognition applied in the usability context as well as...
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Iterative Global Sensitivity Analysis Algorithm with Neural Network Surrogate Modeling
PublicationGlobal sensitivity analysis (GSA) is a method to quantify the effect of the input parameters on outputs of physics-based systems. Performing GSA can be challenging due to the combined effect of the high computational cost of each individual physics-based model, a large number of input parameters, and the need to perform repetitive model evaluations. To reduce this cost, neural networks (NNs) are used to replace the expensive physics-based...
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Wytwarzanie i modyfikacja powierzchni porowatych struktur tytanowych przeznaczonych na implanty
PublicationCelem pracy było wytworzenie stopu Ti-13Nb-13Zr z wykorzystaniem technologii selektywnego topienia laserowego (SLM) oraz jego biofunkcjonalizacja za pomocą utleniania mikrołukowego (MAO), a następnie określenie wpływu parametrów procesowych na właściwości otrzymanych materiałów pod kątem ich zastosowania na implanty. Oceniono wpływ napięcia, natężenia i czasu procesu MAO przeprowadzanego w elektrolicie zawierającym wapń i fosfor...