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Search results for: NUMERICAL MODEL UPDATING
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Damaged plasticity model - seismic analysis of structure of the Petronas Twin Towers (Kuala Lumpur) in Malaysia
PublicationThe article presents numerical simulations for the modelling of seismic impact on the structure of Petronas Twin Towers (Kuala Lumpur) in Malaysia with application of two methods. The Response Spectrum method, in which a spectrum of the structure's responses to an earthquake's impact is generated and the Acceletogram (BETA) method, in which we generate dynamic load in the form of a diagram of the connection between acceleration...
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Automated Reduced Model Order Selection
PublicationThis letter proposes to automate generation of reduced-order models used for accelerated -parameter computation by applying a posteriori model error estimators. So far,a posteriori error estimators were used in Reduced Basis Method (RBM) and Proper Orthogonal Decomposition (POD) to select frequency points at which basis vectors are generated. This letter shows how a posteriori error estimators can be applied to automatically select...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublicationThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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Behawioralny model tranzystora IGBT
PublicationW artykule przedstawiono rezultaty prac nad uniwersalnym modelem tranzystora bipolarnego z izolowaną bramką (IGBT), przydatnym w symulacjach układów energoelektronicznych wymagających odwzorowania stanów ustalonych i dynamicznych. Rozważono behawioralny model IGBT w układzie klasycznym z nieliniowymi aproksymacjami pojemności pasożytniczych. Eksperymentalne testy modelu modułu IGBT typu CM200DY-24A (Mitsubishi) przeprowadzono w...
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Looking for a model of the contemporary university
PublicationPunktem wyjścia jest dokument Manifesto Empower European Universities dignozujący najważniejsze zadania czekające współczesne uczelnie europejskie. Są nimi: dywersyfikacja, umiędzynarodowienie i doskonalenie zarządzania. W tym kontekście autor artykułu zastanawia się na tym: gdzie jesteśmy?, dokąd zmierzamy? oraz jak tam dojść?, odnosząc pytania do polskich uniwersytetów. W konkluzji proponuje model uniwersytetu społecznie odpowiedzialnego.
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Novel strategies to enhance hydrodynamic cavitation in a circular venturi using RANS numerical simulations
PublicationHydrodynamic cavitation is a popular advanced oxidation technique and it has received wide range of applications from waste water treatment to the nanoparticles synthesis in recent years. The enhancement of the intensity of the hydrodynamic cavitation is always been an emerging field of research. Within this framework, we have proposed and investigated three distinct strategies to enhance the intensity of cavitation in a circular...
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Special model for coated woven fabrics.
PublicationW pracy przedstawiono podstawowe równania konstytutywne modelu sieci gęstej oraz podano parametry materiałowe dla dwu wybranych tkanin technicznych. Opisano specjalny model elementu skończonego w płaskim stanie naprężenia, który opisuje typowe właściwości tkaniny technicznej. Zaproponowano rozszerzony wariant modelu sieci gęstej, tzw. Warstwowy model sieci gęstej, w celu bezpośredniego uwzględnienia wpływu pokrycia.
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Suitability study of hybrid model of electrodynamic actuator
PublicationThe paper presents the proposal of the hybrid circumferential model of an electrodynamic actuator. The field model uses the inductor current as the input data which is obtained from the circumferential model or experimentally.
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The behavioural model of graphene field-effect transistor
PublicationThe behavioural model of a graphene field-effect transistor (GFET) is proposed. In this approach the GFET element is treated as a “black box” with only external terminals available and without considering the physical phenomena directly. The presented circuit model was constructed to reflect steady-states characteristics taking also into account GFET capacitances. The authors’ model is defined by a relatively small number of equations...
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Reduced order model of 2d system
PublicationA new method of modelling is developed for static and dynamic analysis of two-dimensional elastic bodies. In the analysis, an elastic body is divided into strips. For each one-dimensional strip the reduced modal model is build up. The modal model contains appropriate number of inputs and outputs to connect lumped interaction that occur between strips. Proposed method of modelling enables to obtain more accurate and more simple...
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The numerical simulation of two-dimensional vertical incompressible viscous flow
PublicationW artykule przedstawiono numeryczne symulacje płaskiego pionowego przepływu nieściśliwej cieczy lepkiej ze swobodną powierzchnią. Zastosowano model bazujący na rozwiązaniu równań Naviera-Stokesa metodą "ciśnień" (SIMPLE). Przy takim podejściu otrzymano dywergencję równań Naviera-Stokesa oraz równanie Poissona na ciśnienie. W rozwiązaniu zastosowano schemat Laxa-Wendroffa z przesuniętą siatką Eulera. Takie podejście zapewnia dokładność...
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Suitability study of hybrid model of electrodynamic actuator
PublicationThis paper presents the proposal of the hybrid circuit-field model of an electrodynamic actuator. The field model uses the inductor current as the input data which is obtained from the circuit model or experimentally. The field model implemented using the FLUX program makes it possible to easily determine the pressure distribution acting on the disc. The results have been verified experimentally.
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EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF CONCRETE BEHAVIOUR AT MESO-LEVEL DURING QUASI-STATIC SPLITTING TENSION
PublicationThe paper describes experimental and numerical results of quasi-static splitting tensile tests on concrete specimens at meso-scale level. The loading strip was made of plywood or steel. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: 3D x-ray micro-computed tomography, 2D scanning electron microscope and manual 2D digital microscope. The discrete element method was used to directly...
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Numerical Analysis of Impact of Energy Buoy Anchoring Configurations on its Motion and Efficiency
PublicationThis paper presents a numerical analysis of the impact of energy buoy mooring configurations on its movement on the wave and effectiveness. The method used to analyse the buoy movement modelling in six degrees of freedom was described in a paper presented at the Conference 2011. Simulations of the buoy movement in regular wave and power calculations were conducted for several configurations of anchoring systems and position of...
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3D Computer Model of the Hip Joint Cartilage
PublicationThis paper presents 3D computer model of the hip joint cartilage in the ANSYS program. Model is made on the basis of anatomy and collected data on the material constants of bone and cartilage components. Analysis and comparison of biochemical model, viscoelastic and molecular mixed - aggregation serves to facilitate the creation of the next model of reality, which could be used in the design of joint prostheses. The correctness...
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Waveguide model of the hearing aid earmold system
PublicationBackground The earmold system of the Behind-The-Ear hearing aid is an acoustic system that modifies the spectrum of the propagated sound waves. Improper selection of the earmold system may result in deterioration of sound quality and speech intelligibility. Computer modeling methods may be useful in the process of hearing aid fitting, allowing physician to examine various earmold system configurations and choose the optimum one...
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Waveguide model of the hearing aid earmold system
PublicationBackground The earmold system of the Behind-The-Ear hearing aid is an acoustic system that modifies the spectrum of the propagated sound waves. Improper selection of the earmold system may result in deterioration of sound quality and speech intelligibility. Computer modeling methods may be useful in the process of hearing aid fitting, allowing physician to examine various earmold system configurations and choose the optimum one...
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Model zużycia abrazyjnego betonów cementowych.
PublicationW monografii przedstawiono analityczny model zużycia abrazyjnego betonów cementowych. Zużycie abrazyjne betonów opisano krzywymi zużycia ubytków masy i prędkości zużycia w funkcji czasu. Zaproponowany model pozwala na sporządzenie charakterystyk zużycia betonów w funkcji cech materiałowych badanych betonów oraz oddziaływania środowiska. Wykazano różnice w przebiegu zużycia betonów zwykłych i wysokowartościowych.Kolokwium habilitacyjne:...
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Numerical analyses of novel prefabricated structural wall panels in residential buildings based on laboratory tests in scale 1:1
PublicationThe paper presents experimental and numerical investigations on novel prefabricated composite building wall panels for residential building constructions. The wall panels were composed of reinforced concrete ribbed elements with the core from the EPS foam as the thermal insulation. The wall panels in the full-scale 1:1 were subjected to vertical loads. In the first step, the experiments were analysed with simple usual static methods....
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A Proposed Machine Learning Model for Forecasting Impact of Traffic-Induced Vibrations on Buildings
PublicationTraffic-induced vibrations may cause various damages to buildings located near the road, including cracking of plaster, cracks in load-bearing elements or even collapse of the whole structure. Measurements of vibrations of real buildings are costly and laborious. Therefore the aim of the research is to propose the original numerical algorithm which allows us to predict, with high probability, the nega-tive dynamic impact of traffic-induced...
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Concept of Generic IT Organization Evolution Model
PublicationThe purpose of this publication is to present a generic model of the IT organization evaluation process as an attempt to systematize and describe the continuous actions and changes in the organization.
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Numerical Study of the Impinging Jets Formed by an Injector with Different Nozzle Diameters
PublicationThe collision of two or more liquid jets may provide considerable atomisation and efficient mixing of injected substances at the same time. This phenomenon is used, among others, in rocket engines, where the fuel and oxidiser are introduced separately and almost immediately mixed through self-impingement. Depending on the injection and operating conditions, diverse configurations of impinging jets are used, such as doublets,...
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Numerical Analysis of the Unsteady Propeller Performance in the Ship Wake Modified by Different Wake Improvement Devices
PublicationThe paper presents summary of numerical analysis of the unsteady propeller forces and induced pressure pulses generated by the selected real propeller of 7000 tons product tanker, operating in five different wakefields including four inflenced by the different wake improvement devices. The results of the analysis are partly compared with experimental data and univocal conclusions about the optimum wake improvement device are presented.
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Dynamic model of nuclear power plant turbine
PublicationThe paper presents the dynamic multivariable model of Nuclear Power Plant steam turbine. Nature of the processes occurring in a steam turbine causes a task of modeling it very difficult, especially when this model is intended to be used for on-line optimal process control (model based) over wide range of operating conditions caused by changing power demand. Particular property of developed model is that it enables calculations...
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Operational Enhancement of Numerical Weather Prediction with Data from Real-time Satellite Images
PublicationNumerical weather prediction (NWP) is a rapidly expanding field of science, which is related to meteorology, remote sensing and computer science. Authors present methods of enhancing WRF EMS (Weather Research and Forecast Environmental Modeling System) weather prediction system using data from satellites equipped with AMSU sensor (Advanced Microwave Sounding Unit). The data is acquired with Department of Geoinformatics’ ground...
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A Circuital Model of Electric Arc in a Circuit Breaker
PublicationThe paper presents a circuital model of arc in a circuit breaker. The model is intended to be used in simulations of the electric circuits transients. It was implemented in the ATP simulation program. The article presents also a few simulation examples of simple DC and AC circuit containing described arc model.
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Odwieczny model dziejów Rosji
PublicationThe article discusses a dual model of the history of Russia presented in the speeches ofPolish Romantics included in the Russian studies texts of the following epochs and inthe works of Russian authors, e.g. Yuri Lotman and Boris Uspensky. The author provesthat the Gnostic-Manichaean influence on the religiousness of Russians is the sourceof their accumulation of rebellion against the world and the human...
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Numerical Solution of the Two-Dimensional Richards Equation Using Alternate Splitting Methods for Dimensional Decomposition
PublicationResearch on seepage flow in the vadose zone has largely been driven by engineering and environmental problems affecting many fields of geotechnics, hydrology, and agricultural science. Mathematical modeling of the subsurface flow under unsaturated conditions is an essential part of water resource management and planning. In order to determine such subsurface flow, the two-dimensional (2D) Richards equation can be used. However,...
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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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Numerical study on seismic response of a base-isolated building modelled with shell elements
PublicationSeismic isolation is counted among the most popular and effective means of protecting structures against earthquake forces. Base isolators, like Lead-Rubber Bearings (LRB), High-Damping Rubber Bearings (HDB) or Friction Pendulum Systems (FPS) are extensively used in practice in many earthquake-prone regions of the world. The present paper reports the results obtained from the numerical study on seismic response of a base-isolated...
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Modelling of spirometry - the application for diagnostic purposes
PublicationThe process of the tissue oxygen supply is the fundamental process of the human life. The lung functioning consists of three processes: the ventilation, the perfusion and the diffusion. The paper deals with one of these processes which is the ventilation process. The quality of the pulmonary ventilation has a strong influence on the patient's health condition. Numerous limitations are imposed on conditions of the lung quality measurement,...
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Global sensitivity analysis of membrane model of abdominal wall with surgical mesh
PublicationThe paper addresses the issue of ventral hernia repair. Finite Element simulations can be helpful in the optimization of hernia parameters. A membrane abdominal wall model is proposed in two variants: a healthy one and including hernia defect repaired by implant. The models include many uncertainties, e.g. due to variability of abdominal wall, intraabdominal pressure value etc. Measuring mechanical properties with high accuracy...
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Efficient analysis of structures with rotatable elements using model order reduction
PublicationThis paper presents a novel full-wave technique which allows for a fast 3D finite element analysis of waveguide structures containing rotatable tuning elements of arbitrary shapes. Rotation of these elements changes the resonant frequencies of the structure, which can be used in the tuning process to obtain the S-characteristics desired for the device. For fast commutations of the response as the tuning elements are rotated, the...
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SMAQ - A Semantic Model for Analitical Queries
PublicationWhile the Self-Service Business Intelligence (BI) becomes an important part of organizational BI solutions there is a great need for new tools allowing to construct ad-hoc queries by users with various responsibilities and skills. The paper presents a Semantic Model for Analytical Queries – SMAQ allowing to construct queries by users familiar with business events and terms, but being unaware of database or data warehouse concepts...
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Geometric Algebra Model of Distributed Representations
PublicationFormalism based on GA is an alternative to distributed representation models developed so far-Smolensky's tensor product, Holographic Reduced Representations (HRR) and Binary Spatter Code (BSC). Convolutions are replaced by geometric products, interpretable in terms of geometry which seems to be the most natural language for visualization of higher concepts. This paper recalls the main ideas behind the GA model and investigates...
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Nuclear Power Plant Steam Turbine - Modeling for Model Based Control Purposes
PublicationThe nature of the processes taking place in a nuclear power plant (NPP) steam turbine is the reason why their modeling is very difficult, especially when the model is intended to be used for on-line optimal model based process control over a wide range of operating conditions, caused by changing electrical power demand e.g. when combined heat and power mode of work is utilized. The paper presents three nonlinear models of NPP steam...
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The impact of the temperament model on the behavior of an autonomous driver
PublicationBecause it is generally believed that the personality and temperament of a human driver influence his/her behavior on the road, the article presents a computational model of the temperament of an autonomous agent - a driver. First, a short review of the four ideas of Galen’s temperament in psychology is presented. Temperament traits are grouped into four other sets, one of which is chosen for implementation in the project of integration...
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Empirical Propagation Model for the Container Terminal Environment
PublicationIn the paper the empirical propagation model for mobile radio links in a container terminal environment is presented and the investigated environment Deepwater Container Terminal in Gdansk, Poland) is characterized. Described empirical model was elaborated on the basis of almost 290 thousand propagation path measurements in real conditions. The diversity of conditions occurring in different places of the container terminal has...
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New Generation of Water lubricated Foil bearing - Numerical Models and Experimental Verification
PublicationIn the paper a new idea of foil water lubricated bearing and methodology of hydrodynamic characteristics calculations is presented. To assesses the theoretical characteristics of these bearings two different computer models were built. First is structural model coupled with fluid model. It takes into account: fluid flow in the deformed fluid gap, specific design of bearing support and friction in bearing support. The second is...
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Liapunov instability of the hypoplastic model for soils.
PublicationWskazanie na konieczność wprowadzenia do hipoplastycznego modelu konstytutywnego tzw. sprężystego jądra. Bez niego model okazuje się być niestabilny w sensie Liapunowa.
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A fuzzy logic model for forecasting exchange rates
PublicationThis article is devoted to the issue of forecasting exchange rates. The objective of the conducted research is to develop a predictive model with the use of an innovative methodology - fuzzy logic theory - and to evaluate its effectiveness in times of prosperity and during the financial crisis. The model is based on sets of rules written by the author in the form of IF-THEN, where expert knowledge is stored. This model is the result...
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Minichannel and minigap classification criteria based on the aspect ratio of the minigeometry: A numerical study
PublicationA detailed numerical investigation has been carried out to analyze the diabatic flow distribution and velocity profile in 18 minigeometries with various aspect ratios for V-type and I-type flow configurations (for 36 cases) assuming ethanol as a working fluid. The aim of the study is to distinguish the value of the aspect ratio for which the flow in minigeometry starts to be two-dimensional (minigap). Cases with a constant Reynolds...
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Usability of Mobile Applications: A Consolidated Model
PublicationMobile devices have become an integral part of the digital ecosystem, connecting people, businesses, and information around the world in ways never before possible. In particular, smartphones, tablets and other handheld devices equipped with mobile applications have changed every aspect of our lives. Today, a user can choose from nearly five million applications available for both Android and iOS operating systems. However, only...
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An Empirical Propagation Model for Corridors in Office Buildings
PublicationThis paper presents an empirical propagation path loss model for corridors in office buildings. The proposed model estimates changeable character of radio signal attenuation, based on a special approach as a combination of the simple free-space model with the author’s model. The measurement stand and measurement scenario are described. The propagation path loss research have been made in corridor for different frequencies in range...
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Komputerowy model 3D stawu biodrowego
PublicationW pracy przedstawiono stworzony w programie ANSYS komputerowy model 3D stawu biodrowego. Model wykonano w oparciu o budowę anatomiczną oraz zebrane dane dotyczące stałych materiałowych kości i elementów chrzęstnych. Analiza i porównanie modelu biochemicznego, lepkosprężystego, mieszanego oraz molekularno – agregacyjnego służy ułatwieniu stworzenia modelu najbliższego rzeczywistości, który można by wykorzystać w projektowaniu endoprotez...
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SIMULATION MODEL OF ASON/GMPLS ARCHITECTURE
PublicationGrowing demands of information society concerned with sophisticated applications could be satisfied by ASON/GMPLS architecture comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS). The ASON/GMPLS proposition represents the future direction of Next Generation Network (NGN) architecture. Therefore considerable work has to be done to examine this solution. In this aspect...
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Toward knowledge-grid model for academic purposes
PublicationNowadays we face a huge amount of data and information sharing on the Web by different users worldwide. For example, the academic environment is one of such places where teachers share and manage knowledge for groups of students. This paper proposes a multi-dimensional knowledge space model, designed to distribute and manage knowledge resources efficiently. We view our model as a foundation of a knowledge grid platform. Two crucial...
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Risk Analysis by a Probabilistic Model of the Measurement Process
PublicationThe aim of the article is presentation of the testing methodology and results of examination the probabilistic model of the measurement process. The case study concerns the determination of the risk of an incorrect decision in the assessment of the compliance of products by measurement. Measurand is characterized by the generalized Rayleigh distribution. The model of the meas-urement process was tested in parallel mode by six risk...
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The Effect of the Selection of Three-Dimensional Random Numerical Soil Models on Strip Foundation Settlements
PublicationThis paper delivers a probabilistic attempt to prove that the selection of a random three-dimensional finite element (FE) model of a subsoil affects the computed settlements. Parametricanalysis of a random soil block is conducted, assuming a variable subsoil Young’s modulus inparticular finite elements. The modulus is represented by a random field or different-sized setsof random variables; in both cases, the same truncated...