Filters
total: 41954
-
Catalog
- Publications 16357 available results
- Journals 1529 available results
- Conferences 286 available results
- Publishing Houses 1 available results
- People 1474 available results
- Inventions 15 available results
- Projects 37 available results
- Laboratories 4 available results
- Research Teams 1 available results
- Research Equipment 1 available results
- e-Learning Courses 708 available results
- Events 30 available results
- Open Research Data 21511 available results
displaying 1000 best results Help
Search results for: computer-aided engineering, design automation, finite-element method (fem), microwave circuits, modelorder reduction (mor), reduced-basis methods (rbms).
-
Schematiclab.com – A web tool for the design and analysis of electrical circuits
PublicationIn this paper a useful Internet application for designing electronic systems is considered. A practical process of prototyping electronic devices by using such a dedicated web tool, hereinafter referred to as SchematicLab, is described. This solution, still in constant development, is now ready for use.
-
Schematiclab.com – A web tool for the design and analysis of electrical circuits
PublicationAlong with a general progress in the modern computational tools, dynamic development of Internet applications using the cloud methodology and solutions is now observed. Clearly, also the applications installed locally, and being commonly used previously, are gradually gaining their counterparts in computational network clouds. The clouds have also brought new service sales opportunities. Namely, the service sales model based on...
-
Virtual Engineering Object (VEO): Toward Experience-Based Design and Manufacturing for Industry 4.0
PublicationIn this article we propose the concept, its framework, and implementation methodology for Virtual Engineering Objects (VEO). A VEO is the knowledge representation of an engineering object that embodies its associated knowledge and experience. A VEO is capable of adding, storing, improving, and sharing knowledge through experience. Moreover, it is demonstrated that VEO is a specialization of a Cyber-Physical System (CPS). In this...
-
Analytical design method of reverse curves
PublicationThe paper deals with a new approach relating to the design of the region of railway track direction alteration adapted to Mobile Satellite Measurements technique. The method may be particularly useful in situations when both the straights of the route directions cannot be connected in an elementary way using a circular arc with transition curves; this also refers to the application of a compound curve. Thus the only solution becomes...
-
Comparison of noise reduction methods in radiometric correlation measurements of two-phase liquid-gas flows
PublicationTwo-phase liquid-gas flows occur frequently in the mining, energy, chemical, and petrochemical industries. One of non-contact methods used to analyse these flows is the gamma ray absorption method. However, the signals received from radiation detectors contain a significant stochastic noise, which makes them difficult to analyse. The article describes four methods of noise reduction in cross-correlation measurements of water-air...
-
Evaluating the effectivness of an outsourced processes on the basis of key performance indicators
PublicationAccording to the statistics outsourcing has become typical solution for mature economies. Besides short run attempt based on cost reduction, getting popular is the method of increasing the effectiveness by implementing outsourced process. Authors in this article present the methods of measuring outsourcing performance on the basis of key performance indicators.
-
On the low-cost design of abbreviated multisection planar matching transformer
PublicationA numerically demanding wideband matching transformer composed of three nonuniform transmission lines (NUTLs) has been designed and optimized at a low computational cost. The computational feasibility of the design has been acquired through the exploitation of low-fidelity NUTL models in most steps of the design procedure and an implicit space mapping optimization engine, providing high accuracy results with only a handful of EM...
-
Human Factors and Cognitive Engineering in Functional Safety Analysis
PublicationHuman factors and cognitive engineering are considered nowadays as important multidisciplinary domains that focus on improving the relations between humans, technology and systems to be supervised and operated. The industrial automation and control systems (IACS) in hazardous plants are increasingly computerized and perform various safety functions. These are usually designed and implemented according to the functional safety requirements....
-
Applications of the discrete green's function in the finite-difference time-domain method
PublicationIn this paper, applications of the discrete Green's function (DGF) in the three-dimensional (3-D) finite-difference time-domain (FDTD) method are presented. The FDTD method on disjoint domains was developed employing DGF to couple the subdomains as well as to compute the electromagnetic field outside these subdomains. Hence, source and scatterer are simulated in separate subdomains and updating of vacuum cells, being of little...
-
Destruction of shell structures under the dynamic load on the human skull trauma basis
PublicationThe main aim of this work is to investigate patterns of potential orbital bone fractures due to mechanical injuries. The solution of the main problem is followed by analysis of several testing examples having straight correlation with civil engineering structures, in which materials of wide range of stiffness are applied. To solve the main problem, the three-dimensional finite element method (FEM) model of the orbital region has...
-
Expedited simulation-driven design optimization of UWB antennas by means of response features
PublicationIn this work, a method for fast design optimization of broadband antennas is considered. The approach is based on a feature-based optimization (FBO) concept where reflection characteristics of the structure at hand are formulated in terms of suitably defined feature points. Redefinition of the design problem allows for reducing the design optimization cost, because the dependence of feature point coordinates on antenna dimensions...
-
COMBINING FUNCTIONAL AND AESTHETIC ASPECTS OF DAYLIGHTING IN SUSTAINABLE ARCHITECTURE WITH THE USE OF DIGITAL DESIGN METHODS
PublicationThe aesthetics of modern architecture should relate to its origins and goals - the environment, function, sustainability and its users. One of the conditions that meet the criteria is the presence of daylight and the use of its potential. The contemporary digital tools that support the design process allow to controlling the use of difficult and capricious materials, such as daylight. They also combine daylighting aspects with...
-
FEM approach to modeling of an irregular trabecular structure
PublicationThe aim of the study is elaboration of a method for creating irregular scaffolds that can be used to model the behaviour of trabecular bone placed in the proximal epiphysis of the femur. The scope of the study encompasses creating six numerical models of irregular scaffolds (two solid irregular scaffolds, two shell irregular scaffolds and two shell irregular scaffolds with fortification) and performing numerical analysis of the...
-
Knowledge-Based Expedited Parameter Tuning of Microwave Passives by Means of Design Requirement Management and Variable-Resolution EM Simulations
PublicationThe importance of numerical optimization techniques has been continually growing in the design of microwave components over the recent years. Although reasonable initial designs can be obtained using circuit theory tools, precise parameter tuning is still necessary to account for effects such as electromagnetic (EM) cross coupling or radiation losses. EM-driven design closure is most often realized using gradient-based procedures,...
-
Inline Microwave Filters With N+1 Transmission Zeros Generated by Frequency-Variant Couplings: Coupling-Matrix-Based Synthesis and Design
PublicationA general coupling-matrix-based synthesis methodology for inline Nth-order microwave bandpass filters (BPFs) with frequency-variant reactive-type couplings that generate N+1 transmission zeros (TZs) is presented in this brief. The proposed approach exploits the formulation of the synthesis problem as three inverse nonlinear eigenvalue problems (INEVPs) so that the coupling matrix is built from their sets of eigenvalues. For this...
-
FEM analysis of composite materials failure in nonlinear six field shell theory
PublicationThe monography deals with the problem of failure initiation in thin laminated composites. Known techniques of laminate structures modelling are briefly characterised. Eventually, shell based approach is chosen for the purpose of the description of the composite structures behaviour, as it predicts their deformation and states of stress effectively in a global sense. The nonlinear six parameter shell theory (6p theory) with asymmetric...
-
Computer-assisted enzyme engineering by modification of tunnels, channels and gates
Publication -
Modelling of high frequency dynamic responses of engineering structures
PublicationModelling of high frequency dynamic responses of engineering structures, especially those related to wave propagation, is a real numerical challenge. Nowadays most of numerical models, used for that purpose, are based on the application of various finite element techniques. However, finite element discrete models may also be considered as possessing certain periodic structures, which may manifest themselves in particular scenarios....
-
CHEMICAL ENGINEERING RESEARCH & DESIGN
Journals -
DESIGN AUTOMATION FOR EMBEDDED SYSTEMS
Journals -
Design thinking qualifications framework – standardizing the innovative approach to entrepreneurial education delivery to engineering students
PublicationHighly competitive labor market stimulates increasing expectations towards fresh university alumni. It is not enough to be an expert - well educated and often experienced - in chosen discipline. High variability of the business environment, continuous change, number of risks, together with higher work demand than supply, shape clear employers’ expectations: entrepreneurial employees are wanted. On this ground a need for entrepreneurial...
-
The Influence of Articular Cartilage Thickness Reduction on Meniscus Biomechanics
PublicationObjective Evaluation of the biomechanical interaction between meniscus and cartilage in medial compartment knee osteoarthritis. Methods The finite element method was used to simulate knee joint contact mechanics. Three knee models were created on the basis of knee geometry from the Open Knee project. We reduced the thickness of medial cartilages in the intact knee model by approximately 50% to obtain a medial knee osteoarthritis...
-
An attempt to develop a model selection algorithm of computer simulation during the design process of mechanical response of any mechanical body
Publicationn the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This article...
-
FEM Calculations in Analysis of Steel Subsea Water Injection Flowlines Designing Process
PublicationPaper describes the result of theoretical research aimed at assessing the loads and operating conditions of a Coiled Tubing pipeline injecting water, suspended to the mining platform of Lotos Petrobaltic. For this purpose, appropriate calculation models have been developed using the Finite Element Method (FEM), taking into account the nature of the analyzed object and its loads. The analyzes were carried out for two pipes (previously...
-
Non-Destructive Testing of the Longest Span Soil-Steel Bridge in Europe—Field Measurements and FEM Calculations
PublicationThe article describes interdisciplinary and comprehensive non-destructive diagnostic tests of final bridge inspection and acceptance proposed for a soil-steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure short-term response was collected. Periodic diagnostics of bridge deformations was done one...
-
Numerical Methods - Data Engineering
e-Learning Coursesstudia inżynierskie, informatyka i inżynieria danych
-
A novel degree-hour method for rational design loading
PublicationCooling degree-hours (CDH) received the broadest application in evaluation of the ambient air cooling efficiency in power engineering (engine intake air cooling systems) and air conditioning. The current CDH numbers are defined as a drop in air temperature multiplied by associated time duration of performance and their summarized annual number is used to estimate the annual effect achieved due to sucked air cooling in power plants...
-
Two-center radial basis function network for classification of soft faults in electronic analog circuits
PublicationW pracy zaproponowano specjalizowaną sieć neuronową z dwucentrowymi radialnymi funkcjami bazowymi (TCRB) neuronów w warstwie ukrytej,przeznaczoną do diagnostyki uszkodzeń parametrycznych układów analogowych. Zastosowanie funkcji TCRB pozwala na znaczne zmniejszenie liczby neuronów w warstwie ukrytej, lepsze dopasowanie do słownika uszkodzeń oraz poprawę dokładności klasyfikacji, w porównaniu z dotychczas stosowaną siecią z jednocentrowymi...
-
Multi-Fidelity Local Surrogate Model for Computationally Efficient Microwave Component Design Optimization
PublicationIn order to minimize the number of evaluations of high-fidelity (“fine”) model in the optimization process, to increase the optimization speed, and to improve optimal solution accuracy, a robust and computational-efficient multi-fidelity local surrogate-model optimization method is proposed. Based on the principle of response surface approximation, the proposed method exploits the multi-fidelity coarse models and polynomial interpolation...
-
Study of displacements of a bridge abutment using FEM
PublicationSteel sheet piles are often used to support excavations for bridge foundations. When they are left in place in the permanent works, they have the potential to increase foundation bearing capacity and reduce displacements; but their presence is not usually taken into account in foundation design. In this article, the results of finite element analysis of a typical abutment foundation, with and without cover of sheet piles, are presented...
-
Validation Process for Computational Model of Full-Scale Segment for Design of Composite Footbridge
PublicationExperimental tests and numerical simulations of a full-scale segment of a foot and cycle bridge made of polymer composites are presented in the paper. The analysed structure is made of sandwich panels, which consist of glass fibre reinforced polymer (GFRP) multi-layered laminate faces and a PET foam (obtained from recycling) core. The dimensions of the segment cross-section are the same as for the target footbridge; however, span...
-
Simulation-driven design of compact ultra-wideband antenna structures
PublicationPurpose–The purpose of this paper is to investigate strategies and algorithms for expedited designoptimization and explicit size reduction of compact ultra-wideband (UWB) antennas.Design/methodology/approach–Formulation of the compact antenna design problem aiming atexplicit size reduction while maintaining acceptable electrical performance is presented. Algorithmicframeworks are described suitable for handling various design situations...
-
Analysis of Historic Brick Walls' Strengthening Methods
PublicationAnalysis of the behavior of historical brick walls is difficult and complicated. However, computer calculations are being increasingly used in the evaluation of cultural heritage buildings and some of their elements. The aim of this paper is to analyze the historic brick walls reinforcement. Different methods of strengthening are compared and discussed. Numerical analysis, based on finite element method, was conducted on the assumption...
-
A method of self-testing of analog circuits based on fully differential op-amps with theTCBF classifier
PublicationA new approach of self-testing of analog circuits based on fully differential op-amps of mixed-signal systems controlled by microcontrollers is presented. It consists of a measurement procedure and a fault diagnosis procedure. We measure voltage samples of a time response of a tested circuit on a stimulation of a unit step function given at the common-mode reference voltage input of the op-amp. The fault detection and fault localization...
-
Application of Reverse Engineering Technology in Part Design for Shipbuilding Industry
PublicationIn the shipbuilding industry, it is difficult to create CAD models of existing or prototype parts, especially with many freeform surfaces. The paper presents the creation of the CAD 3D model of a shipbuilding component with the application of the reverse engineering technology. Based on the data obtained from the digitization process, the component is reconstructed in point cloud processing programs and the CAD model is created....
-
Application of the Boundary Element Method for the Simulation of Two-dimensional Viscous Incompressible Flow
PublicationThe paper presents the application of an indirect variant of the boundary element method (BEM) to solve the two-dimensional steady flow of a Stokes liquid. In the BEM, a system of differential equations is transformed into integral equations. Thi smakes it possible to limit discretization to the border of the solution. Numerical discretization of the computational domain was performed with linear boundary elements, for which a...
-
Computer-aided Analysis of Induced Sheath Voltages in High Voltage Power Cable System
PublicationThis paper concerns the effect of configuration of high voltage power cables on induced voltages in their metallic sheaths. One, two or three cables per phase and phase sequence of the cables are considered. Computing of the voltages was performed for a normal operation and in case of earth fault. Various ways of the sheaths bonding are considered as well. Shock hazard and voltage stress of non-metallic outer sheath of cables are...
-
Quality evaluation of computer aided information retrieval from machine typed paper documents
PublicationCelem międzynarodowego projektu memorial jest wspomagane komputerowo rozpoznawanie maszynopisów. Referat prezentuje zagadnienie pomiaru jakości takiego procesu. Wskazano w nim potencjalne miejsca pojawiania się błędów oraz przedstawiono i sklasyfikowano odpowiednie miary.
-
Engineering method of tire rolling resistance evaluation
PublicationTire rolling resistance is one of the most difficult tire parameters to measure. The reason is that for modern tires the force of rolling resistance corresponds to 0.5–1% of tire load, thus measurements of very small forces must be performed in a heavily loaded system. This constitutes great problems, especially in road conditions. Laboratory measurements are easier to perform, as the environment may be better controlled, but roadwheel...
-
Rapid multi-objective design optimisation of compact microwave couplers by means of physics-based surrogates
PublicationThe authors introduce a methodology for fast multi-objective design optimisation of miniaturised microwave couplers. The approach exploits the surrogate-based optimisation paradigm with an underlying low-fidelity model constructed from an equivalent circuit of the structure under consideration, corrected through implicit and frequency space mapping. A fast prediction tool obtained this way is subsequently optimised by a multi-objective...
-
ARCHIVES OF COMPUTATIONAL METHODS IN ENGINEERING
Journals -
A new anisotropic bending model for nonlinear shells: Comparison with existing models and isogeometric finite element implementation
PublicationA new nonlinear hyperelastic bending model for shells formulated directly in surface form is presented, and compared to four existing prominent bending models. Through an essential set of elementary nonlinear bending test cases, the membrane and bending stresses of each model are examined analytically. Only the proposed bending model passes all the test cases, while the other bending models either fail or only pass the test cases for...
-
AN OVERVIEW OF HEAT TRANSFER ENHANCEMENT BASED UPON NANOPARTICLES INFLUENCED BY INDUCED MAGNETIC FIELD WITH SLIP CONDITION VIA FINITE ELEMENT STRATEGY
PublicationThe mathematical model of heat generation and dissipation during thermal energy transmission employing nanoparticles in a Newtonian medium is investigated. Dimensionless boundary layer equations with correlations for titanium dioxide, copper oxide, and aluminium oxide are solved by the finite element method. Parameters are varied to analyze their impact on the flow fields. Various numerical experiments are performed consecutively...
-
Ryszard S. Romaniuk profesor
PeopleProfessor of Electronics, Computer and Communications Engineering at Warsaw University of Technology, Poland; Eisenhower Fellow, Philadelphia, MA USA; SPIE Fellow, Bellingham, WA USA; Editor-in-Chief, International Journal of Electronics and Telecommunications, Polish Academy of Sciences; Photonics Spectra Magazine, EAB Member;
-
An improved method for flow boiling heat transfer with account of the reduced pressure effect
PublicationIn the paper are presented the results using the authors own model to predict heat transfer coefficient during flow boiling. The model has been tested against a large selection of experimental data to investigate the sensitivity of the in-house developed model. In the work are presented the results of calculations obtained using the semi-empirical model on selected experimental flow boiling data of the refrigerants: R134a, R1234yf,...
-
Inverse modeling for fast design optimization of small-size rat-race couplers incorporating compact cells
PublicationIn the paper, a framework for computationally-efficient design optimization of compact rat-race couplers (RRCs) is discussed. A class of hybrid RRCs with variable operating conditions is investigated, whose size reduction is obtained by replacing ordinary transmission lines with compact microstrip resonant cells (CMRCs). Our approach employs a bottom-up design strategy leading to the development of compact RRCs through rapid design...
-
Mechanical model of fascia-implant structure. Finite element simulation.
PublicationPraca dotyczy modelowania i symulacji syntetycznych implantów chirurgicznych stosowanych w leczeniu przepulin brzusznych metodą laparoskowpową. Prponowane są modele matematyczne a ich prawidłowość weryfikowana jest na podstawie badań doświadczalnych zachowania się modeli fizycznych wszczepionych implantów pod wpływem obciążeń wynikających z fizjologii człowieka. Nakreślona jest metodologia oceny trwałości połączenia siatki chirurgicznej...
-
Finite element description of nonlinear viscoelastic behaviour of technical fabric
PublicationW pracy podano propozycję nieliniowego modelowania zachowania się tkaniny technicznej. Podano wyniki identyfikacji i zweryfikowano poprzez numeryczną symulację prób laboratoryjnych
-
Experiences with viscoplastic constitutive equations in finite element shell analysis
PublicationW pracy przedstawiono problemy zastosowania lekoplastycznych równań konstytutywnych w anlizie powłok metodą elementów skończonych. Pokazano historie rozwoju tego rodzaju modeli. Rozważono podstawowe założenia jakie muszą być zrobione.Omówiono doświadczenia konieczne do identyfikacji parametrów materiałowych modeli. Przedstawiono problemy jakie mogą wynikną w analizie numerycznej (problemy dokładności i stabilności algorytmów) Pracę...
-
System of protection against electric shock for circuits with power electronics converters
PublicationModern low voltage circuits are very often equipped with power electronics converters, therefore in these circuits non-sinusoidal earth currents (touch currents) may occur. For non-sinusoidal currents safety criteria should be modified. This paper presents these modified criteria and a computer system of protection against electric shock which can be implemented in circuits with power electronics converters. The system is based...