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Search results for: NUMERICAL WEATHER PREDICTION MODEL METEOROLOGICAL DATA
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Model of optical phantoms thermal response upon irradiation with 975 nm dermatological laser
PublicationWe have developed a numerical model describing the optical and thermal behavior of optical tissue phantoms upon laser irradiation. According to our previous studies, the phantoms can be used as substitute of real skin from the optical, as well as thermal point of view. However, the thermal parameters are not entirely similar to those of real tissues thus there is a need to develop mathematical model, describing the thermal and...
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Syntetyczne wskaźniki oceny stanu toru
PublicationJakość geometryczna toru analizowana jest w różnych celach, a dane podlegają różnemu stopniowi agregacji. Pojedyncze nierówności toru analizowane są zazwyczaj z uwagi na bezpieczeństwo i służą do planowanie napraw w krótkich terminach. Natomiast agregacja pomierzonych parametrów pozwala na planowanie robót w terminach średniookresowych i budowę modeli predykcji. W artykule przedstawiono zagregowane wskaźniki jakości geometrycznej...
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An absorbing set for the Chialvo map
PublicationThe classical Chialvo model, introduced in 1995, is one of the most important models that describe single neuron dynamics. In order to conduct effective numerical analysis of this model, it is necessary to obtain a rigorous estimate for the maximal bounded invariant set. We discuss this problem, and we correct and improve the results obtained by Courbage and Nekorkin (2010). In particular, we provide an explicit formula for an...
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Automatic recognition of therapy progress among children with autism
PublicationThe article presents a research study on recognizing therapy progress among children with autism spectrum disorder. The progress is recognized on the basis of behavioural data gathered via five specially designed tablet games. Over 180 distinct parameters are calculated on the basis of raw data delivered via the game flow and tablet sensors - i.e. touch screen, accelerometer and gyroscope. The results obtained confirm the possibility...
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Analysis of the Capability of Deep Learning Algorithms for EEG-based Brain-Computer Interface Implementation
PublicationMachine learning models have received significant attention for their exceptional performance in classifying electroencephalography (EEG) data. They have proven to be highly effective in extracting intricate patterns and features from the raw signal data, thereby contributing to their success in EEG classification tasks. In this study, we explore the possibilities of utilizing contemporary machine learning algorithms in decoding...
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Forewarned Is Forearmed: Machine Learning Algorithms for the Prediction of Catheter-Induced Coronary and Aortic Injuries
PublicationCatheter-induced dissections (CID) of coronary arteries and/or the aorta are among the most dangerous complications of percutaneous coronary procedures, yet the data on their risk factors are anecdotal. Logistic regression and five more advanced machine learning techniques were applied to determine the most significant predictors of dissection. Model performance comparison and feature importance ranking were evaluated. We identified...
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Bearing Capacity of aluminum bars with built-up cross section and glued or welded connections
PublicationThe paper is focused on numerical analysis and experimental test of aluminum bars with glued and welded connections between separate members. The connection properties were tested experimentally. The numerical analysis were conducted for the beam and shell model of the structure. The shape and magnitude of initial geometric imperfection was taken into account
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Multi-objective design optimization of antennas for reflection, size, and gain variability using kriging surrogates and generalized domain segmentation
PublicationCost-efficient multi-objective design optimization of antennas is presented. The framework exploits auxiliary data-driven surrogates, a multi-objective evolutionary algorithm for initial Pareto front identification, response correction techniques for design refinement, as well as generalized domain segmentation. The purpose of this last mechanism is to reduce the volume of the design space region that needs to be sampled in order...
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Use of numerical methods in the analysis of traction energy systems—an overview of the practical examples
PublicationA characteristic feature of trolleybus transport is the random nature of traffic caused by congestion. It predestinates statistical and numerical methods for the analysis of trolleybus energy system. There are presented 3 methods of trolleybus traction system analysis: simulation of supply system based on Monte Carlo method, analysis of energy recovery potential based on statistical data analysis and benchmark of trolleybus supply...
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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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High-Resolution Discharge Forecasting for Snowmelt and Rainfall Mixed Events
PublicationDischarge events induced by mixture of snowmelt and rainfall are strongly nonlinear due to consequences of rain-on-snow phenomena and snowmelt dependence on energy balance. However, they received relatively little attention, especially in high-resolution discharge forecasting. In this study, we use Random Forests models for 24 h discharge forecasting in 1 h resolution in a 105.9 km 2 urbanized catchment in NE Poland: Biala River....
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Experimental and Computational Analysis of the Ship Propeller in Open Water Conditions for Inclined Flow
PublicationThe paper presents the results of computational analyses simulating the open water tests of ship propeller in inclined flow. The results of computations are compared with the results of corresponding experimental analyses carried out in the towing tank of Ship Design and Research Centre (CTO S.A.). The object of the research was the model propeller identified as CP469. The aim of the study was to validate the results of numerical...
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Comparative Analysis of Numerical and Experimental Studies of the Airflow Around the Sample of Urban Development
PublicationIn this paper, on the background of a short overview of the recent advances in the field of Environmental Wind Engineering (EWE), a comparison of wind tunnel experiment and numerical simulation for some cases of airflow around an urban layout have been reported. The purpose of the study is quantitative and qualitative comparison of measurements in the wind tunnel as well as numerical simulation using Ansys Fluent software. The...
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Performance of Noise Map Service Working in Cloud Computing Environment
PublicationIn the paper a noise map service designated for the user interested in environmental noise subject is presented. It is based on cloud computing. Noise prediction algorithm and source model, developed for creating acoustic maps, are working in cloud computing environment. In the study issues related to noise modeling of sound propagation in urban spaces are discussed with a special focus on road noise. Examples of results obtained...
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Road traffic can be predicted by machine learning equally effectively as by complex microscopic model
PublicationSince high-quality real data acquired from selected road sections are not always available, a traffic control solution can use data from software traffic simulators working offline. The results show that in contrast to microscopic traffic simulation, the algorithms employing neural networks can work in real-time, so they can be used, among others, to determine the speed displayed on variable message road signs. This paper describes...
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Identification of category associations using a multilabel classifier
PublicationDescription of the data using categories allows one to describe it on a higher abstraction level. In this way, we can operate on aggregated groups of the information, allowing one to see relationships that do not appear explicit when we analyze the individual objects separately. In this paper we present automatic identification of the associations between categories used for organization of the textual data. As experimental data...
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Evaluation of Pavement Temperatures in Poland During Winter Conditions
PublicationThe paper presents the analysis of pavement temperatures from meteorological stations located at the Polish national roads during the impact of low winter temperatures. Presented issue is particularly important in view of the problem of low-temperature cracks that occur in the asphalt pavement under the influence of low temperatures. For each location of meteorological station there were analysed measurements of the temperature...
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Full-scale CFD simulations for the determination of ship resistance as a rational, alternative method to towing tank experiments
PublicationResults of ship resistance predictions obtained from towing tank experiments are affected by the method used to extrapolate from a model scale to a ship scale. Selection of method to determine a form factor is subjective and the extrapolation method is accurate for typical hull forms. For innovative hull forms the proper method for calculating the form factor is questionable. Moreover, the influence of the extrapolation method...
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Numerical and experimental investigation of rotational stiffness of zed-purlins connection with sandwich panels
PublicationA rotational resistant stiffness of the zed-purlins connection with sandwich panels is investigated. A simple finite element method model of the connection is proposed. The numerical analysis of the model performed by ABAQUS software, in physically linear and geometrically nonlinear ranges, leads to the rotational resistant stiffness sought. The numerical solution obtained is verified experimentally. Two variants of distribution...
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Inverse Analysis as a Key Element of Safety Assessment under the Snow Load For The Large Suspension Roofs Structure
PublicationThe paper presents a concept and realization of monitoring system for the Silesian Stadium in Chorzow. The idea of the system lies in fusion of structure monitoring with a calibrated numerical FEM model [1]. The inverse problem is solved. On the base of measured selected displacements, the numerical FEM model of the structure combined with iterative method, develops the current snow load distribution. Knowing the load, we can calculate...
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Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
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Collective citizens' behavior modelling with support of the Internet of Things and Big Data
PublicationIn this paper, collective human behaviors are modelled by a development of Big Data mining related to the Internet of Things. Some studies under MapReduce architectures have been carried out to improve an efficiency of Big Data mining. Intelligent agents in data mining have been analyzed for smart city systems, as well as data mining has been described by genetic programming. Furthermore, artificial neural networks have been discussed...
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Prediction of coking dynamics for wet coal charge
PublicationA one-dimensional transient mathematical model describing thermal and flow phenomena during coal coking in an oven chamber was studied in the paper. It also accounts for heat conduction in the ceramic oven wall when assuming a constant temperature at the heating channel side. The model was solved numerically using partly implicit methods for gas flow and heat transfer problems. The histories of temperature, gas evolution and internal...
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Experimental and numerical investigation of mercury removal from flue gas by sorbent polymer composite
PublicationThis paper presents an experimental and numerical investigation of the performance of a sorbent polymer composite (SPC) material used for removing mercury from the flue gases in a full-scale industrial installation. The investigated material is an attractive alternative to activated carbon, which is commonly used for this purpose. While the application of the SPC is characterized by high capital expenditures, this technology offers...
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Rapid antenna design optimization using shape-preserving response prediction
PublicationAn approach to rapid optimization of antennas using the shape-preserving response-prediction (SPRP) technique and coarsediscretization electromagnetic (EM) simulations (as a low-fidelity model) is presented. SPRP allows us to estimate the response of the high-fidelity EM antenna model, e.g., its reflection coefficient versus frequency, using the properly selected set of so-called characteristic points of the low-fidelity model...
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Autonomous Ship Utility Model Parameter Estimation Utilising Extended Kalman Filter
PublicationIn this paper, a problem of autonomous ship utility model identification for control purposes is considered. In particular, the problem is formulated in terms of model parameter estimation (one-step-ahead prediction). This is a complex task due to lack of measurements of the parameter values, their time-variability and structural uncertainty introduced by the available models. In this work, authors consider and compare two utility...
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Pressure pulsations in turbine blade seal clearance
PublicationThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...
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Discrete element method modelling of elastic wave propagation in a meso-scale model of concrete
PublicationThis paper deals with the accurate modelling of ultrasonic wave propagation in concrete at the mesoscopic level. This was achieved through the development of a discrete element method (DEM) model capable of simulating elastic wave signals comparable to those measured experimentally. The main objective of the work was to propose a novel methodology for constructing a meso-scale model of concrete dedicated to the analysis of elastic...
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AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublicationThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
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Energy consumption optimization in wastewater treatment plants: Machine learning for monitoring incineration of sewage sludge
PublicationBiomass management in terms of energy consumption optimization has become a recent challenge for developed countries. Nevertheless, the multiplicity of materials and operating parameters controlling energy consumption in wastewater treatment plants necessitates the need for sophisticated well-organized disciplines in order to minimize energy consumption and dissipation. Sewage sludge (SS) disposal management is the key stage of...
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Monte Carlo simulations of the fracture resistance degradation of asphalt concrete subjected to environmental factors
PublicationThe paper presents the results of laboratory tests of SCB (semi-circular beam) samples of asphalt concrete, subjected to the destructive effect of water and frost as well as the aging processes. The determined values of material parameters show significant dispersions, which makes the design of mixtures difficult. Statistical analysis of the test results supplemented by computer simulations made with the use of the proprietary...
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Inżynieria odwrotna bazy paliw płynnych w Gdańsku
PublicationArtykuł prezentuje prace z zakresu pozyskania danych o zbiornikach bazy paliw płynnych w Gdańsku. Przedstawione rozwiązanie nie ogranicza się tylko do stworzenia (rejestracji) chmury punktów, ale jest próbą wskazania użycia naziemnego skaningu laserowego do stworzenia bazy informacji o bazie paliw – w tym głównie geometrii zbiorników. Autorzy prezentują proces inwentaryzacji, rejestrację chmury punktów oraz wskazują zasady tworzenia...
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Multicomponent ionic liquid CMC prediction
PublicationWe created a model to predict CMC of ILs based on 704 experimental values published in 43 publications since 2000. Our model was able to predict CMC of variety of ILs in binary or ternary system in a presence of salt or alcohol. The molecular volume of IL (Vm), solvent-accessible surface (Sˆ), solvation enthalpy (DsolvGN), concentration of salt (Cs) or alcohol (Ca) and their molecular volumes (Vms and Vma, respectively) were chosen...
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Modelling of FloodWave Propagation with Wet-dry Front by One-dimensional Diffusive Wave Equation
PublicationA full dynamic model in the form of the shallow water equations (SWE) is often useful for reproducing the unsteady flow in open channels, as well as over a floodplain. However, most of the numerical algorithms applied to the solution of the SWE fail when flood wave propagation over an initially dry area is simulated. The main problems are related to the very small or negative values of water depths occurring in the vicinity of...
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Review of Selected Methods for Prediction of Added Resistance in Following Waves
PublicationThe added resistance in waves is a mean value of non-linear, second order reaction of a ship to incoming waves. In the beginning of the 20th century, the experimental methods for investigation of ship hydrodynamics at model scale were developed. They allowed the evaluation of added resistance by measurements in irregular waves (directly) or by measurements in regular waves (in-direct method). The main goal was to find more precise...
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ANALYSIS OF CLIMATIC ZONES IN POLAND WITH REGARD TO ASPHALT PERFORMANCE GRADING
PublicationTowards the end of the last century a new system of bitumen grading was developed and implemented as part of the American Strategic Highway Research Program (SHRP). Its aim was to better adjust the testing methods and requirements for road bitumens to the actual conditions in which those bitumens serve in road pavements. Currently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard...
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Coastline change-detection method using remote sensing satellite observation data
PublicationCoastal zones are not only the fundaments for local economics based on trade, shipping and transport services, but also a source of food, energy and resources. Apart from offering diverse opportunities for recreation and tourism, coastal zones provide protection against storms and other meteorological disturbances. Environmental information is also essential because of the direct influence on a country’s maritime zones, which are...
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Influence of Installation Effects on Pile Bearing Capacity in Cohesive Soils – Large Deformation Analysis Via Finite Element Method
PublicationIn this paper, the whole process of pile construction and performance during loading is modelled via large deformation finite element methods such as Coupled Eulerian Lagrangian (CEL) and Updated Lagrangian (UL). Numerical study consists of installation process, consolidation phase and following pile static load test (SLT). The Poznań site is chosen as the reference location for the numerical analysis, where series of pile SLTs...
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Influence of nodes with positive eccentricity on load-carrying capasity of truss' top chords in trusses made of welded cold-formed members.
PublicationIn order to establish the influence of eccentric crossing of truss members on the load-carrying capacity of the folded chord of a hat-section truss, a research model was created and preliminary numerical analysis of the truss was performed with the use of Marc Mentat programme. Distorial instability of crossheads caused by deviation of loose (unmounted) channel section web’s bends was observed. Due to the slenderness of the section’s...
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Solving the Problem of Dynamic Adaptability of Artificial Intelligence Systems that Control Dynamic Technical Objects
PublicationThis paper investigates the increase in the response speed and stability of artificial intelligence systems that control dynamic technical objects. The problem of calculating the optimal time of switching an artificial intelligence system between software classes by the criterion of the rigidity degree of the model of a control object is considered. The solution of this problem is proposed for the general case of the control object...
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Numerical estimation of the pile toe and shaft unit resistances during the installation process in sands
PublicationNumerical simulations of a pile jacking were carried out. A Coupled Eulerian–Lagrangian (CEL) formulation was used to treat with large deformation problems. An Abaqus, a commercial Finite Element Method software suit, was used as a computing environment. The Mohr–Coulomb constitutive model was applied and the Coulomb model of friction was used to describe pile-soil interaction. Calculations were made for three different pile diameters....
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublicationIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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MONITORING SYSTEM OF THE ROAD EMBANKMENT
PublicationThe paper presents the analysis of the monitoring system of the embankment supported on concrete columns and overlaid by a load transfer platform with the embedded steel grid. This field investigation was to study the complex interaction among the columns, the load transfer platform layer, and steel grid via in situ measurements during erection and live loading of the embankment. The study was focused on the behaviour of steel...
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Simplified, multiregional fuzzy model of a nuclear power plant steam turbine
PublicationPower systems, including steam turbines and synchronous generators, are complex nonlinear systems with parameters varying over time. The paper presents the developed simplified, multiregional fuzzy model of the steam turbine of a nuclear power plant turbine generator set and compares the results with a full nonlinear model and commonly used linear input-output model of a steam turbine. The proposed model consist of series of linear...
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Smart and resilient cities- new challanges for Polish cities in terms of 2020 energy efficiency and climate action
PublicationGlobal climate change action along with energy efficiency optimizations are becoming increasingly pressing principles in terms of moving towards sustainable development. As a member of EU and UN Poland is also obliged to follow restricted rules concerning energy efficiency of buildings which come to force in 2020. To meet new goals, innovative approaches - like moving towards smart and resilient cities -may be required. Through...
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Multiscale model for blood flow after a bileaflet artificial aortic valve implantation
PublicationCardiovascular diseases are the leading cause of mortality in the world, mainly due to atherosclerosis and its consequences. The article presents the numerical model of the blood flow through artificial aortic valve. The overset mesh approach was applied to simulate the valve leaflets motion and to realize the moving mesh, in the aortic arch and the main branches of cardiovascular system. To capture the cardiac system’s response...
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Numerical modelling and analysis of steel specimens subjected to marine immersed corrosion and tensile load
PublicationThe present study develops numerical models to analyse the behaviour of steel specimens subjected to marine immersed corrosion degradation and tensile load. The finite element method with the use of the explicit dynamic solver LS-DYNA, satisfying the quasi-static conditions, is employed. Two numerical models are developed, where in the first one, the scans of surfaces gathered from corroded plate specimens are implemented directly...
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Intelligent Decision Forest Models for Customer Churn Prediction
PublicationCustomer churn is a critical issue impacting enterprises and organizations, particularly in the emerging and highly competitive telecommunications industry. It is important to researchers and industry analysts interested in projecting customer behavior to separate churn from non‐churn consumers. The fundamental incentive is a firm’s intent desire to keep current consumers, along with the exorbitant expense of gaining new ones....
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Modelling and Measurement of Folk Guitar: Truss Rod and Strings in Numerical Analysis of Tone
PublicationThe study makes an attempt to model a complete vibrating guitar including its non-linear features, specifically the tension-compression of truss rod and tension of strings. The purpose of such a model is to examine the influence of design parameters on tone. Most experimental studies are flawed by uncertainties introduced by materials and assembly of an instrument. Since numerical modelling of instruments allows for deterministic...
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EXPERIMENTS AND SIMULATIONS FOR LAPAROSCOPICVENTRAL HERNIA REPAIR IMPROVEMENT
PublicationThe authors conducted a wide experimental and numerical study in order to determine effective approaches in the laparoscopic VH repair. At first the study covered identification of mechanical properties of the abdominal fascia, implants, tacks and transabdominalsutures. Basis on these data, the one and two-dimensional mathematical models were formulated and a number of numerical static and dynamic analyses were carried out. Then...