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Wyniki wyszukiwania dla: FINTE ELEMENT METHOD MECHATRONIC SYSTEMS
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EFFICIENT LINE DETECTION METHOD BASED ON 2D CONVOLUTION FILTER
PublikacjaThe article proposes an efficient line detection method using a 2D convolution filter. The proposed method was compared with the Hough transform, the most popular method of straight lines detection. The developed method is suitable for local detection of straight lines with a slope from -45˚ to 45˚. Also, it can be used for curve detection which shape is approximated with the short straight sections. The new method is characterized...
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Exploring application relationships within enterprise system by matching messages in enterprise log
PublikacjaWith data becoming their key asset, large enterprises require data governance processes to maintain its quality. Because a large portion of business value in enterprise systems is usually delivered by legacy applications without proper documentation, there is a need for a better understanding of these applications and the data produced by them. In this paper, we present an approach to collecting insights into the data managed by...
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Hybrid Analysis of Structures Composed of Axially Symmetric Objects
Publikacja— A hybrid method for the scattering problems in shielded and open structures is presented. The procedure is based on the combination of body-of-revolution involving finite-element methods with impedance matrix formulation and the mode-matching technique, which can be utilized for the analysis of structures with axially symmetrical scatterers. In order to confirm the validity and efficiency of the proposed approach, a few examples...
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Application of Spinel and Hexagonal Ferrites in Heterogeneous Photocatalysis
PublikacjaSemiconducting materials display unique features that enable their use in a variety of applications, including self-cleaning surfaces, water purification systems, hydrogen generation, solar energy conversion, etc. However, one of the major issues is separation of the used materials from the process suspension. Therefore, chemical compounds with magnetic properties have been proposed as crucial components of photocatalytic composites,...
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Praktyczne zastosowania analizy wrażliwości na przykładzie projektowania tarczy
PublikacjaW pracy przedstawiono przykłady zastosowania analizy wrażliwości przy projektowaniu tar-czy. Badano wpływ zmian grubości obszarów tarczy – zmiennej projektowej – na przemiesz-czenie wybranego punktu tarczy – zmiennej stanu. Zaproponowano metodę projektowania polegającą na zwiększeniu grubości obszarów tarczy, których wpływ na wariację zmiennej stanu (wrażliwość) jest największa. Do obliczeń numerycznych korzystano z metody elemen-tów...
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Reduced model of gyroscopic system
PublikacjaThe paper presents the method of model reduction for the system with gyroscopic interactions. Two methods were used to obtain the approximate discrete models of the continuous structure: the modal decomposition method and the rigid finite element method. The first approach is used for this part of a system for which it is easy to formulate orthogonality conditions, meanwhile the second one is used for other part. The method enables...
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Efficient model order reduction for FEM analysis of waveguide structures and resonators
PublikacjaAn efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...
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Computational modelling of historic masonry railroad arch bridges
PublikacjaThe problems encountered during the analyzes of structural response of historic masonry railroad arch bridges are described in this paper. The attention is mainly focused on the stiffness of the masonry arches, their strengths and appropriate estimation of railroad load intensity. Issues related to computational modelling of two, existing, almost 130 years old masonry arch railroad bridges are presented in this context. The main...
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Finite element/mode-matching analysis of ferrite/dielectric line junctions of arbitrary cross-section
PublikacjaThis paper is focused on the analysis of line junctions obtained as a cascade of dielectric and ferrite guides of arbitrary cross-section. The main application of such structures is nonreciprocal devices such as isolators, circulators, or phase shifters. The efficient finite element/mode-matching approach is proposed to the analysis of such structures. In this approach, thefiniteelementmethod is applied todetermine propagation...
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Determination of vertical displacements by using the hydrostatic levelling systems with the variable location of the reference sensor,
PublikacjaAbstract: In this paper, the author proposed a new method for determination of vertical displacements with the use of hydrostatic levelling systems. The traditional method of hydrostatic levelling uses a rule in which a position of reference sensor is stable. This assumption was not adapted in the proposed method. Regarding the issue mentioned above, the reference sensor is treated in the same way as the others sensors that measure...
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Exploring Relationships Between Data in Enterprise Information Systems by Analysis of Log Contents
PublikacjaEnterprise systems are inherently complex and maintaining their full, up-to-date overview poses a serious challenge to the enterprise architects’ teams. This problem encourages the search for automated means of discovering knowledge about such systems. An important aspect of this knowledge is understanding the data that are processed by applications and their relationships. In our previous work, we used application logs of an enterprise...
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Softly Switched Robustly Feasible Model Predictive Control for Nonlinear Network Systems
PublikacjaIt is common that an efficient constrained plant operation under full range of disturbance inputs require meeting different sets of control objectives. This calls for application of model predictive controllers each of them being best fit into specific operating conditions. It further requires that not only designing robustly feasible model predictive controllers is needed to satisfy the real plant state/output constraints, but...
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An MOR Algorithm Based on the Immittance Zero and Pole Eigenvectors for Fast FEM Simulations of Two-Port Microwave Structures
PublikacjaThe aim of this article is to present a novel model-order reduction (MOR) algorithm for fast finite-element frequency-domain simulations of microwave two-port structures. The projection basis used to construct the reduced-order model (ROM) comprises two sets: singular vectors and regular vectors. The first set is composed of the eigenvectors associated with the poles of the finite-element method (FEM) state-space system, while...
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Characterization of novel trehalose synthase from Deinococcus geothermalis.
PublikacjaThe method of trehalose extraction from yeast or othernatural sources is unsuitable for industrial production becauseof its low yield and high cost. Thus, the trehalose synthesizingenzyme systems that originated from a few microorganisms have been investigated.
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Voice Multilateration System
PublikacjaThis paper presents an innovative method of locating airplanes, which uses only voice communication between an air traffic controller and the pilot of an aircraft. The proposed method is described in detail along with its practical implementation in the form of a technology demonstrator (proof of concept), included in the voice communication system (VCS). A complete analysis of the performance of the developed method is presented,...
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Communication Model Order Reduction in Hybrid Methods Involving Generalized Impedance Matrix
PublikacjaA novel strategy for the efficient analysis of frequency-domain scattering electromagnetic problems in open and closed domains is presented. A fully automatic model-order reduction technique, called the enhanced reduced-basis method, is applied to increase the efficiency of the hybrid approach, which combines the finite-element and mode-matching methods. Numerical tests show that the proposed algorithm yields reliable and highly...
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CAUSALITY IN MODELS OF THERMAL PROCESSES IN SHIP ENGINE ROOMS WITH THE USE OF BOND GRAPH (BG) METHOD
PublikacjaWith a single approach to modeling elements of different physical nature, the method of Bond Graph (BG) is particularly well suited for modeling energy systems consisting of mechanical, thermal, electrical and hydraulic elements that operate in the power system engine room. The paper refers to the earlier presented new concept of thermal process modeling using the BG method. The authors own suggestions for determining causality...
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O projektowaniu ściany szczelinowej
PublikacjaW pracy przedstawiono proces weryfikacji i porównania obliczeń otrzymanych z programu bazującego na metodzie elementów skończonych z wynikami analitycznymi dla analizowanej ściany szczelinowej z przyporą ziemną. Dodatkowo autorzy dokonali krótkiego przeglądu literatury z zakresu ścian szczelinowych.
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Dowodzenie w Policji – koncepcja zmian w zakresie dowodzenia formacją
PublikacjaThe dynamic development of human civilization at the turn of the 20th and 21st centuries unfortunately generates not only positive developments. So we need to constantly improve crisis management systems. The purpose of the research was to improve the police command system. Primarily, the research was based on the methods of non-standard observation and analysis and logical construction. The article presents the command in the...
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Assessment of Road Restraint Systems in Polish Conditions
PublikacjaKey to understanding the needs and tools of road infrastructure management is identifying the hazards and their sources involved in having no or faulty road restraint systems. Clarity is also needed on why the systems are wrongly designed, constructed, built and operated. To ensure that the problem is adequately understood, research and site observations were conducted and...
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Tailoring structural properties of lanthanum orthoniobates through an isovalent substitution on the Nb-site
PublikacjaTetragonal polymorph of lanthanum orthoniobate can be stabilized to room temperature by the substitution of Nb with an isovalent element. LaNb1-xAsxO4 (0 < x ≤ 0.3), where As is an element stabilizing tetragonal structure, were successfully synthesized with combined co-precipitation and solid-state reaction method. The phase transition temperature, above which the material has tetragonal structure, decreases linearly with increasing...
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System of innovation: a sectoral approach
Publikacjathe article presents a systems approach to innovation as an alternative method of assessing the sector innovativeness. in the article the building blocks of each sectoral system of innovations (ssi) such as a knowledge base, institutions and actors are discussed. moreover, the five models of ssi are presented.
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Interactive Decision Making, Inżynieria Środowiska, Environmental Engineering, 2023/2024 (summer semester)
Kursy OnlineThe course is designed for students of MSc Studies in Environmental Engineering (studies in Polish and English) Person responsible for the subject, carrying out lectures and tutorials: mgr inż. Agata.Siemaszko; agata.siemaszko@pg.edu.pl The person conducting the lectures and tutorials: dr inż. Anna Jakubczyk-Gałczyńska; anna.jakubczyk@pg.edu.pl The course is conducted using the Project-Based Learning (PBL) method. It provides...
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Complex multidisciplinary optimization of turbine blading systems
PublikacjaThe paper describes the methods and results of direct optimization of turbine blading systems using a software package Opti_turb. The final shape of the blading is obtained from minimizing the objective function, which is the total energy loss of the stage, including the leaving energy. The current values of the objective function are found from 3D RANS computations (from a code FlowER) of geometries changed during the process...
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A Subspace-Splitting Moment-Matching Model-Order Reduction Technique for Fast Wideband FEM Simulations of Microwave Structures
PublikacjaThis article describes a novel model-order reduction (MOR) approach for efficient wide frequency band finite-element method (FEM) simulations of microwave components. It relies on the splitting of the system transfer function into two components: a singular one that accounts for the in-band system poles and a regular part that has no in-band poles. In order to perform this splitting during the reduction process, the projection...
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Information Retrieval with the Use of Music Clustering by Directions Algorithm
PublikacjaThis paper introduces the Music Clustering by Directions (MCBD) algorithm. The algorithm is designed to support users of query by humming systems in formulating queries. This kind of systems makes it possible to retrieve songs and tunes on the basis of a melody recorded by the user. The Music Clustering by Directions algorithm is a kind of an interactive query expansion method. On the basis of query, the algorithm provides suggestions...
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Differential analysis of dynamic immittance spectra
PublikacjaThis work presents a new approach to the analysis of immittance spectrograms of systems characterised by non-stationarity. The possibility of linking the evolution of the immittance response with changes in the parameters describing the system is achieved by introducing a spectrum in differential form. By using the above procedure, it becomes possible to separate elements with a dependence (or lack thereof) from an independent...
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Buckling and initial post-local buckling behaviour of cold-formed channel member flange
PublikacjaThe initial post-buckling behaviour of a cold-formed channel member flange after its local buckling is investigated. An axially compressed column or beam subjected to pure bending is considered. The member material is assumed to follow a linear stress-strain relationship. The governing non-linear differential equation of the problem is derived using the minimum total potential energy principle. An approximate solution for the equation...
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Modal parameters identification with Particle Swarm Optimization
PublikacjaThe paper presents method of the modal parameters identification based on the Particle Swarm Optimization (PSO) algorithm [1]. The basic PSO algorithm is modified in order to achieve fast convergence and low estimation error of identified parameters values. The procedure of identification as well as algorithm modifications are presented and some simple examples for the SISO systems are provided. Results are compared with the results...
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Numerical modeling of wave-seabed-structure interaction.
PublikacjaPraca doktorska przedstawia propozycję nowoczesnego rozwiązania obciążeń hydraulicznych przy uwzględnieniu nieliniowych oddziaływań pomiędzy falą wodną, przepuszczalnym dnem i porowatą konstrukcją morską. Nabrzeże pionowe, falochron podwodny i falochron kompozytowy były obiektem eksperymentów numerycznych, których wyniki były weryfikowane przy użyciu wyników laboratoryjnych (niszczących i nieniszczących). Krótki przegląd bieżącej...
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Asymmetrical-Slot Antenna with Enhanced Gain for Dual-Band Applications
PublikacjaDual-band operation is an important feature of antennas to be applied in modern communication systems. Although high gain of radiators is rarely of concern in urban areas with densely located broadcasting stations, it becomes crucial for systems operating in more remote environments. In this work, a dual-band antenna with enhanced bandwidth is proposed. The structure consists of a driven element in the form of an asymmetrical radiator/slot...
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Rozkład naprężeń mechanicznych w łyżce o szerokości 500 mm, przeznaczonej do koparki podsiębiernej
PublikacjaW artykule zaprezentowano optymalizację kształtu łyżki koparki przedsiębiernej z wykorzystaniem analizy wytrzymałościowej. Analizę oparto na trójwymiarowym modelu konstrukcji łyżki z zastosowaniem metody elementów skończonych (MES). Opracowanie wspomnianej metody pozwoliło na modyfikację konstrukcji łyżki, która dała w efekcie obniżenie naprężeń złożonych w newralgicznych obszarach konstrukcji łyżki. Przedstawiona analiza okazała...
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FEM approach to estimate the behaviour of biocomposite metal-surface coating system
PublikacjaA three dimensional (3D) model of biocomposite metal-surface coating system, which is influenced byknown external forces, is proposed. This model consists of the metallic substrate (Ti6Al4V) and thehydroxyapatite (HA) coating. Using FEM (finite element method), strain-stress maps of model weregenerated for investigating relations between the extreme stress of HA coating and the magnitude ofexternal force and the thickness of the...
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VOF-DEM-FEM combined model of the reef breakwater collapse
PublikacjaZespolony model numeryczny (metoda modelowania przepływu ze swobodną powierzchnią rozdziału faz ciekłej i gazowej w siatce nieruchomej (ang. Volume of Fluid - VOF, metoda elementów dyskretnych (ang. Distinct Element Method, metoda elementów skończonych (MES)) został wykorzystany do zbadania odkształceń falochronu narzutowego i jego piaszczystego podłoża w wyniku oddziaływania falowania powierzchniowego. Wyniki analizy numerycznej...
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Electromagnetic Simulations with 3D FEM and Intel Optane Persistent Memory
PublikacjaAbstract—Intel Optane persistent memory has the potential to induce a change in how high-performance calculations requiring a large system memory capacity are conducted. This article presents what this change may look like in the case of factorization of large sparse matrices describing electromagnetic problems arising in the 3D FEM analysis of passive highfrequency components. In numerical tests, the Intel oneAPI MKL PARDISO was...
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Modeling of Human Tissue for Medical Purposes
PublikacjaThe paper describes the possibilities offered for medicine by modeling of human tissue using virtual and augmented reality. It also presents three proposals of breast modeling for the use in clinical practice. These proposals are the result of arrangements of medical and computer scientists team (the authors) and will be pursued and implemented in the near future. There is included also a brief description of the most popular methods...
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Diagnostics of historic columns using wave propagation
PublikacjaThis paper presents a numerical analysis of elastic wave propagation in columns of historical buildings for diagnostics purposes. Numerical calculations were performed using the finite element method in the Abaqus software package. The analysis was carried out for three types of brick columns: a full column, a column filled with debris, and a column empty inside. The excitation was in the form of a wave packet and signals of propagating...
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METHOD OF TRAINING THE ENDOSCOPIC VIDEO ANALYSIS ALGORITHMS TO MAXIMIZE BOTH ACCURACY AND STABILITY
PublikacjaIn the article a new training and testing method of endoscopic video analysis algorithms is presented. Classical methods take into account only eciency of recognizing objects on single video frames. Proposed method additionally considers stability of classiers output for real video input. The method is simple and can be trained on data sets created for other solutions. Therefore, it is easily applicable to existing endoscopic video...
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A multi-agent method for periodicity detection in distributed events
PublikacjaMulti-agent systems working in constantly changing environments may be challenged by instantaneous unavailability of their autonomous agents caused e.g. by limited computing resources. A new method of self-organization of distributed service components is proposed, suitable for multi-agent systems. This method relies on particular agents carrying out separate analyzes of their individual processing loads or other specific events....
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublikacjaThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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The study of Arduino Uno feasibility for DAQ purposes
PublikacjaUsing microcontroller systems becomes a routine in various measurement and control tasks. Their wide availability together with a huge potential of extending their functionality by additional modules allows developing advanced measuring and monitoring systems by non-specialists. However, using popular example codes often leads the user to pass over or not to be aware of the limitations of the system and drawing too far-reaching...
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Optimal control at energy performance index of the mobile robots following dynamically created trajectories
PublikacjaIn practice, the problem of motion control of the wheeled mobile robots is often neglected. Wheeled mobile robots are strongly nonlinear systems and restricted by non-holonomic constraints. Motion control of such systems is not trivial task and usage of non-optimal control signals can lead to deterioration of the overall robot system’s performance. In case of autonomous application of the mobile robots all parts of its control...
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Estimation of structural stiffness with the use of Particle Swarm Optimization
PublikacjaThe paper presents the theoretical background and four applications examples of the new method for the estimation of support stiffness coefficients of complex structures modelled discretely (e.g. with the use of the Finite Element Model (FEM) method based on the modified Particle Swarm Optimization (PSO) algorithm. In real-life cases, exact values of the supports’ stiffness coefficients may change for various reasons...
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Axial capacity of steel built-up battened columns
PublikacjaThis paper deals with the numerical investigation aimed to study the axial capacity of pin-ended steel built-up columns. Three methods of calculating forces in chords and batten, taking into account the material and geometric imperfections specified in the Eurocode 3 are considered. The aim of this study was to compare different methods allowing the calculation of the column load capacity and determine a simpler and faster method...
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The influence of chemical composition of amide block on the thermal properties and structure of terpoly(ester-b-ether-b-amide) elastomers
PublikacjaMultiblock terpolymers-(PBT-b-PTMO-b-PA12,10)(n)- constituting the polymer systems, in which one of the three blocks (PBT) does not dissolve in PA12,10 block (hard phase) and, depending on its molecular weight is slightly soluble in PTMO block (soft phase), have been obtained. The DSC method was applied to investigate the thermal properties of these polymers and it was found that PBT block acts as an element that produces stiffness...
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Practical aspects of testing superconducting electromagnets by the capacitor discharge method taking into account the non-linearity of circuit parameters
PublikacjaThe article presents selected issues related to the development and testing of the diagnostics systems dedicated for superconducting electromagnets. The systems were constructed to assess the production quality of superconducting electromagnets of the SIS100 synchrotron, a new accelerator being built as part of the Facility of Antiproton and Ion Research (FAIR). One of the systems is used for automatic checking of electrical connection...
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Risk criteria for sea-going ships arising from the operation of the main engines' crankshaft - conecting rod - piston systems
PublikacjaIn the article the risk criterion for sea-going ships arising from the operation of the main engines' crankshaft - connecting rod - piston systems is proposed. These criterion is based on the procedures recommended in the Formal Safety Assessment method developed under the auspices of International Maritime Organization (IMO). First of all the collective risk criterion for ship has been proposed. In the next step, the share of...
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Voltage control in a power system with renewable sources of energy
PublikacjaIntensive development of distributed generation in power systems, caused by the European Union energy policy, gives possibility for improving safety in power delivery as well as optimizing the costs of the systems functioning. In this context, distributed generation can be used for voltage control in power systems – it can be performed by the control of reactive power of each source of energy or a group of energy sources. This...
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Radar Signal Parameters Estimation Using Phase Accelerogram in the Time-Frequency Domain
PublikacjaRadar signal parameter estimation, in the context of the reconstruction of the received signal in a passive radar utilizing other radars as a source of illumination, is one of the fundamental steps in the signal processing chain in such a device. The task is also a crucial one in electronic reconnaissance systems, e.g. ELINT (Electronic Intelligence) systems. In order to obtain accurate results it is important to measure, estimate...
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Viscous versus electromagnetic damping – amplification in a neighbourhood of a mechanism singular position
PublikacjaIn the paper, damping of vibrations are considered and compared in a mechanical and in a electromechanical system. In the system, a continuous beam is considered as the main vibrating element. The compared dissipations methods are based on: viscous dampers and DC generators. To increase the possible damping effectiveness, velocity amplification is proposed, i.e., a mechanism is introduced between the beam and the damping element....