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Wyniki wyszukiwania dla: OPTIMAL CLAMPING STIFFNESS
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Modern GFRP Composite Footbridges
PublikacjaApplication of GFRP composites in civil engineering is still not large but already noticeable. Advantages of this material, such as: low volume weight, relatively high stiffness and strength, well fatigue resistance, easiness in shaping, high material damping and high environmental resistance, make it attractive for bridge and in particular foot-bridge designers. It is estimated that nowadays in the world there are realized hundreds...
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Experimental Study on Dynamics of Wooden House Wall Panels with Different Thermal Isolation
PublikacjaWood frame buildings are very popular in regions that are exposed to different dynamic excitations including earthquakes. Therefore, their seismic resistance is really important in order to prevent structural damages and human losses. The aim of the present paper is to show the results of experimental tests focused on the dynamic response of wall panels of a wooden frame building with thermal isolation made of mineral wool and...
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Stability analysis of single-walled carbon nanotubes embedded in winkler foundation placed in a thermal environment considering the surface effect using a new refined beam theory
PublikacjaThis article is devoted to investigate the stability of different types of Single Walled Carbon Nanotubes (SWCNTs) such as zigzag, chiral, and armchair types which are rested in Winkler elastic foundations exposing to both the low and high temperature environments. Also, the Surface effects which include surface energy and surface residual stresses, are taken into consideration in this study. It may be noted that the surface energy...
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The vibration-based assessment of the influence of elevated temperature on the condition of concrete beams with pultruded GFRP reinforcement
PublikacjaConcrete beams reinforced with glass fiber reinforced polymer (GFRP) bars subjected to elevated temperature have been experimentally studied. The influence of high temperatures on GFRP-reinforced concrete beams condition has been check both, destructively and nondestructively. The nondestructive tests foresaw vibration-based tests to obtain the natural frequency values after exposure to varying temperatures. The vibration-based...
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Multiparameter sensitivity analysis of a GFRP composite footbridge of a sandwich structure and U-shaped cross-section
PublikacjaThe paper deals with multiparameter sensitivity analysis of a composite footbridge. A shell‐like structure is 14.5 m long shows U‐shaped cross‐section and inner service dimensions 1.3 × 2.5 m. Glass fiber reinforced polymer GFRP laminate constitutes faces of a sandwich structure while PET foam received from recycled bottle builts a core. The structure was divided into 285 independent areas where the thickness of laminates and stiffness...
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Zastosowanie komputerów w dziedzinie wyszukiwania strategii optymalnych w grach logicznych
PublikacjaProblem jaki stanowi wyszukiwanie strategii optymalnej w grach logicznych jest bardzo złożony. Można go podzielić na następujące podproblemy: obliczeniowy, pamięciowy oraz operacji wejścia/wyjścia. Jednak rosnąca z roku na rok siła obliczeniowa komputerów, ilość pamięci oraz prędkość transferu danych pomiędzy podzespołami zarówno lokalnymi jak i rozproszonymi, a także wzrost skuteczności wykorzystywanych technik algorytmicznych...
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Low-dimensional bound entanglement with one-way distillable cryptographic key
PublikacjaIn this paper, we provide a class of bound entangled states that have positive distillable secure key rate. The smallest state of this kind is 4 circle times 4, which shows that peculiar security contained in bound entangled states does not need high-dimensional systems. We show that for these states a positive key rate can be obtained by one-way Devetak-Winter (DW) protocol. Subsequently, the volume of bound entangled key-distillable...
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Construction of phylogenetic trees with topological constraints
PublikacjaThis paper proposes a method of reconstruction of phylogenetic trees based on heuristic search with topological constraints. Using topological constraints it is possible to reduce the set of solutions as well as to enforce that the result is consistent with a given hypothesis about the evolution process within some group of species. Along with this work a number of algorithms used for phylogenetic analysis were implemented. Those...
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Shared multi-processor scheduling
PublikacjaWe study shared multi-processor scheduling problem where each job can be executed on its private processor and simultaneously on one of many processors shared by all jobs in order to reduce the job’s completion time due to processing time overlap. The total weighted overlap of all jobs is to be maximized. The problem models subcontracting scheduling in supply chains and divisible load scheduling in computing. We show that synchronized...
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Calibration of precipitation estimation algorithm with particular emphasis on the Pomeranian region using high performance computing
PublikacjaFast and accurate precipitation estimation is an important element of remote atmosphere monitoring, as it allows, for example, to correct short-term weather forecasts and the prediction of several types of meteorological threats. The paper presents methodology for calibrating precipitation estimation algorithm based on MSG SEVIRI sensor data, and Optimal Cloud Analysis product available via EumetCast transmission. Calibration is...
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Fast Multi-Objective Antenna Optimization Using Sequential Patching and Variable-Fidelity EM Models
PublikacjaIn this work, a technique for fast multi-objective design optimization of antenna structures is presented. In our approach, the initial approximation of the Pareto set representing the best possible trade-offs between conflicting design objectives is obtained by means of sequential patching of the design space. The latter is a stencil-based search that aims at creating a path that connects the extreme Pareto-optimal designs (obtained...
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Fiber optic low-coherence Fabry-Pérot interferometer with ZnO layers in transmission and reflective mode: comparative study
PublikacjaA construction of a low-coherence fiber-optic Fabry-Pérot interferometer using a thin ZnO layer as a reflective surfaces was proposed and examined. In the investigated setup, the ZnO layer of thickness 200 nm were deposited on the face of the standard telecommunication single-mode optical fiber (SMF-28). Measurements of interference signal were performed for the interferometer working in the transmission and reflective mode, as...
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Evaluation of Vehicle Routing Problem Algorithms for Transport Logistics Using Dedicated GIS System
PublikacjaThe development and research related to optimization of fleet management is of high interest among many industrial and scientific entities related to logistics and transport. Optimal distribution of transportation resources leads to significant cost reduction. In this context, scientific research related to so called Vehicle Routing Problem (VRP) which relies on determining the shortest transport routes for a strictly limited number...
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Structural and mechanical properties of hydroxyapatite coatings formed by ion-beam assisted deposition
PublikacjaThe ion-beam assisted deposition (IBAD) is an advanced method capable of producing crystalline coatings at low temperatures. We determined the characteristics of hydroxyapatite Ca10(PO4)6(OH)2 target and coatings formed by IBAD using X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray (EDX). The composition of the coatings'...
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High-Gain Compact Circularly Polarized X-Band Superstrate Antenna for CubeSat Applications
PublikacjaIn this letter, a concept of high-gain circularly polarized X-band antenna employing a partially reflecting surface (PRS) has been presented. In the initial antenna analysis, the influence of parasitic elements size in the PRS structure on antenna radiation pattern parameters has been investigated and the optimal arrangement of the elements has been identified. The proposed antenna provides wide bandwidth of return loss above 10...
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Design space reduction and variable-fidelity EM simulations for feasible Pareto optimization of antennas
PublikacjaA computationally efficient procedure for multi-objective optimization of antenna structures is presented. In our approach, a response surface approximation (RSA) model created from sampled coarse-discretization EM antenna simulations is utilized to yield an initial set of Pareto-optimal designs using a multi-objective evolutionary algorithm. The final Pareto front representation for the high-fidelity model is obtained using surrogate-based...
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Mobile indicators in GIS and GPS positioning accuracy in cities
PublikacjaThe publication describes the possible use of tele-geoprocessing as a synergy of modern IT solutions, telecommunications and GIS algorithms. The paper presents a possibility of urban traffic monitoring with the use of mobile GIS indicators of dedicated monitoring system designed for taxi corporation. The system is based on a stationary and mobile software package. The optimal and minimal assumptions for the monitoring of urban...
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AUTOMATIC OPTIMIZATION OF ADAPTIVE NOTCH FILTER’S FREQUEN CY TRACKING
PublikacjaEstimation of instantaneous frequency of narrowband com- plex sinusoids is often performed using lightweight algo- rithms called adaptive notch filters. However, to reach high performance, these algorithms require careful tuning. The paper proposes a novel self-tuning layer for a recently intr o- ducedadaptive notch filtering algorithm. Analysis shows th at, under Gaussian random-walk type assumptions, the resultin g solution converges...
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Automatic Optimization Of Adaptive Notch Filter’s Frequency Tracking
PublikacjaEstimation of instantaneous frequency of narrowband com- plex sinusoids is often performed using lightweight algo- rithms called adaptive notch filters. However, to reach high performance, these algorithms require careful tuning. The paper proposes a novel self-tuning layer for a recently intr o- ducedadaptive notch filtering algorithm. Analysis shows th at, under Gaussian random-walk type assumptions, the resultin g solution converges...
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Interval incidence coloring of bipartite graphs
PublikacjaIn this paper we study the problem of interval incidence coloring of bipartite graphs. We show the upper bound for interval incidence coloring number (χii) for bipartite graphs χii≤2Δ, and we prove that χii=2Δ holds for regular bipartite graphs. We solve this problem for subcubic bipartite graphs, i.e. we fully characterize the subcubic graphs that admit 4, 5 or 6 coloring, and we construct a linear time exact algorithm for subcubic...
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Towards rainfall interception capacity estimation using ALS LiDAR data
PublikacjaIn this study we develop a spatial model for interception capacity of vegetation based on LiDAR data. The study is conducted in the natural wetland river valley dominated meadows, reeds and small bushes. The multiple regression model was chosen to relate the field measurements of interception capacity and LiDAR statistics at 2m grid. The optimal model was chosen by stepwise selection and further manual variables selection resulting...
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Multiresolution analysis and adaptive estimation on a sphere using stereographic wavelets
PublikacjaWe construct an adaptive estimator of a density function on d dimensional unit sphere Sd (d ≥ 2), using a new type of spherical frames. The frames, or as we call them, stereografic wavelets are obtained by transforming a wavelet system, namely Daubechies, using some stereographic operators. We prove that our estimator achieves an optimal rate of convergence on some Besov type class of functions by adapting to unknown smoothness....
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Corrosion degradation monitoring of ship stiffened plates using guided wave phase velocity and constrained convex optimization method
PublikacjaThe study presents an experimental investigation on the corrosion degradation level assessment using nondestructive wave-based methods. The degradation level of ship structural elements has been assessed in two different ways. The first one is based on the spectral decomposition and zero-crossing incorporated reconstruction of the dispersion curve approach of the antisymmetric Lamb wave mode and the best matching of the theoretical...
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Optimally regularized local basis function approach to identification of time-varying systems
PublikacjaAccurate identification of stochastic systems with fast-varying parameters is a challenging task which cannot be accomplished using model-free estimation methods, such as weighted least squares, which assume only that system coefficients can be regarded as locally constant. The current state of the art solutions are based on the assumption that system parameters can be locally approximated by a linear combination of appropriately...
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Demolition of the cereal elevator building located in the conservation protection zone in the aspect of technical, functional-utility and economic conditions
PublikacjaThe paper presents a description of the technical condition of the Grain Elevator building situated on the port quay, which after many years of operation has been decommissioned. The immediate reason for the cessation of operation was the change in the use profile of the port quay, which caused the handling of other goods at the quay than the bulk materials originally stored in Elewator Zbożowy. The work contains...
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Magdalena Szuflita-Żurawska
OsobyMagdalena Szuflita-Żurawska jest kierownikiem Sekcji Informacji Naukowo-Technicznej na Politechnice Gdańskiej oraz Liderem Centrum Kompetencji Otwartej Nauki przy Bibliotece Politechniki Gdańskiej. Jej główne zainteresowania badawcze koncentrują się w obszarze komunikacji naukowej oraz otwartych danych badawczych, a także motywacji i produktywności naukowej. Jest odpowiedzialna między innymi za prowadzenie szkoleń dla pracowników...
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Multiplicative Long Short-Term Memory with Improved Mayfly Optimization for LULC Classification
PublikacjaLand Use and Land Cover (LULC) monitoring is crucial for global transformation, sustainable land control, urban planning, urban growth prediction, and the establishment of climate regulations for long-term development. Remote sensing images have become increasingly important in many environmental planning and land use surveys in recent times. LULC is evaluated in this research using the Sat 4, Sat 6, and Eurosat datasets. Various...
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Problematyka konstrukcyjna zabytkowego obiektu przywracanego do użytkowania na przykładzie kamienicy przy ul. Staromiejskiej w Olsztynie = Structural aspects in restoring historical buildings for re-use: the case of a tenement building on Staromiejska Street in Olsztyn
PublikacjaThe paper discusses the issue of introducing structural changes into a historical building referring to the example of conservation work carried out in the tenement house at 6 Staromiejska in Olsztyn. Building work involved a general renovation. The paper reviews actions carried out in the restoration work, including strengthening and deepening of the foundations, introducing a post and beam system, and putting...
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Influence of separation gap on the response of colliding models of steel structures under seismic and paraseismic excitations
PublikacjaAs a result of high urbanization, the need to erect closely-spaced buildings forces designers to consider collisions between structures taking place during ground motions. Experimental and numerical studies have confirmed that such collisions (often referred to as structural pounding) may cause serious damage to the structural elements and even lead to total collapse of colliding structures. The main reason of earthquake-induced...
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The Impact of Homogeneity of High Modulus Asphalt Concrete Layer on Low-Temperature Cracking
PublikacjaDuring winter season of 2012 numerous transverse cracks developed in high-modulus asphalt concrete (HMAC) base of newly constructed motorway. Pavement cracked both in transverse joint locations and in the area between them. Research which was conducted during investigation of the causes and mechanisms of cracking consisted of: field examination, laboratory testing of specimens cored out of the existing pavement, computational analyses...
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Diagnosis of Damage in a Steel Tank Model by Shaking Table Harmonic Tests
PublikacjaDiagnosis of damage in civil engineering structures has recently become an important issue in the safety assessment procedure. Among a number of different approaches, a method of measuring the changes in natural frequencies is one of the most effective indicators of global damage. It has been successfully applied to relatively small. structures, however, the tests on large structures are very difficult and the practical application...
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Elastic Fender-Dolphin Interaction for Economic Design of Berthing Dolphins
PublikacjaThe study addresses the question of the possible design benefits when considering the interaction between a modern marine modular rubber fender and a steel tubular pile substructure of a berthing dolphin. Absorption of the berthing kinetic energy of the vessel by a dualelasticity pile-fender berthing system is described in detail using the interactive treatment method (ITM). Application of the ITM is illustrated by a calculative...
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Properties of water in the region between a tubulin dimer and a single motor head of kinesin
PublikacjaA kinesin is a molecular motor that can perform movement on a microtubule track in a stepping-like manner. This motion is connected with processes of association and dissociation of kinesin and tubulin. Water is an important participant in these kinds of molecular interactions. This is why we have decided to investigate the dynamical and structural properties of water in the region between the kinesin catalytic domain and the tubulin...
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The Use of Direct Shear Test for Optimization of Interlayer Bonding Under a Poroelastic Layer
PublikacjaPoroelastic Road Surfaces (PERS) are characterised by porous structure with air void content of 20% or higher and stiffness almost 10 times lower than that of a standard asphalt course. Such properties enable noise reduction by up to 12 dB in comparison to SMA 11 mixture. However, the disadvantage of a poroelastic pavement is its low durability, which partially results from delamination from the lower layer. The paper aims to investigate...
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Nano soil improvement technique using cement
PublikacjaNano soil-improvement is an innovative idea in geotechnical engineering. Nanomaterials are among the newest additives that improve soil properties. Herein, laboratory tests, such as unconfined compressive strength, direct shear test, and initial tests, were conducted to investigate the geotechnical properties of Kelachay clay with micro- and nanosized cement to evaluate its particles in untreated soil and observe changes in the...
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Perceptual and Motor Effects of Muscle Co-activation in a Force Production Task
PublikacjaWe tested several predictions of the theory of motor control with spatial referent coordinates related to effects of muscle coactivation on force production and perception. In particular, we predicted that subjects would produce unintentional force increase by finger flexors and be unaware of this force increase. Healthy subjects performed steady force production task in isometric conditions with visual feedback on the force level....
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Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs
PublikacjaAn insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel Moment Resisting Frames (MRFs) were considered to investigate...
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Rozwijanie kreatywności ucznia w procesie kształtowania umiejętności językowych. Innowacja pedagogiczna z elementami neurodydaktyki w edukacji wczesnoszkolnej
PublikacjaThis text is a ready-to-use pedagogical innovation program combining teaching English and classes developing creativity in early childhood education. Classes developing creativity are a unique opportunity to implement innovative solutions and ideas to develop language competencies and key competencies, which can be difficult during a standard English lesson. The...
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Evolutionary Sets Of Safe Ship Trajectories: A New Approach To Collision Avoidance
PublikacjaThe paper introduces a new method of solving multi-ship encounter situations for both open waters and restricted water regions. The method, called evolutionary sets of safe trajectories combines some of the assumptions of game theory with evolutionary programming and aims to find optimal set of safe trajectories of all ships involved in an encounter situation. In a two-ship encounter situation it enables the operator of an on-board...
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Bis-phosphonated carbon nanotubes: one pot synthesis and their application as efficient adsorbent of mercury
PublikacjaEffective, one-pot method of CNTs phosphonylation is presented. Cheap and readily available reagents are used, so the process can be easily transferred to large-scale production. The product was analyzed using spectroscopic methods (FTIR, UV-vis, XPS). Thermal properties of the bis-phosphonated nanotubes are reported for the first time. Newly obtained material was tested as an adsorbent for mercury removal from water. The sorption...
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Pareto Ranking Bisection Algorithm for Expedited Multi-Objective Optimization of Antenna Structures
PublikacjaThe purpose of this letter is introduction of a novel methodology for expedited multi-objective design of antenna structures. The key component of the presented approach is fast identification of the initial representation of the Pareto front (i.e., a set of design representing the best possible trade-offs between conflicting objectives) using a Pareto-ranking bisection algorithm. The algorithm finds a discrete set of Pareto-optimal...
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On Sample Rate Conversion Based on Variable Fractional Delay Filters
PublikacjaThe sample rate conversion algorithm based on variable fractional delay filters is often used if the resampling ratio cannot be expressed as the ratio of small integer numbers or if it is not constant. The main advantage of such solution is that it allows for arbitrary resampling ratios which can even be changed during the resampling process. In this paper a discussion on influence of different approaches to fractional filter...
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State of the art and prospects of methods for determination of lipophilicity of chemical compounds
PublikacjaLipophilicity of the compounds is useful to (i) explain their distribution in biological systems, which is different in plant and in animal organisms, (ii) predict the possible pathways of pollutant transport in the environment, and (iii) support drug discovery process and select optimal composition in terms of bioactivity and bioavailability. The lipophilic properties can be determined by two main approaches, experimental, which...
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Study on the Influence of an Axial Distance Between Rotors on a Performance of a Small Counter-Rotating Wind Turbine
PublikacjaIn this paper, results of the investigation on the performance of a small counter-rotating wind turbinehas been presented. Computational Fluid Dynamics methodshave been used forwind turbine simulations. Rotors representation were introduced into computational domain by means of Actuator Line Model. Influence of an axial distance of CRWTrotorshas been investigated. In all studied configurations rotors were counter-rotating...
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The Influence of PEG on Morphology of Polyurethane Tissue Scaffold
PublikacjaIn this study, polyurethanes (PU) were synthesized from oligomeric dihydroxy(etylene-butylene adipate), poly(ethylene glycol) (PEG), hexamethylene diisocyanate (HDI), 1,4-butanediol (BDO) as chain extender and stannous octoate as catalyst. PEG due to its hydrophilic character influences physical and chemical properties of PU. For testing were used PU having the following weigh contents of PEG: 0%, 7%, and 14%. Porous scaffolds...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublikacjaThe article introduces a design and analysis results of a prototype ORC (organic Rankine cycle) turbo generator rotor assembly of 300kW power, supported by tilting-pad bearings of original design. The calculations were performed for a prototype turbo generator rotor. The shaft of this machine is supported with two radial bearings, lubricated with an unusual lubricant – a low-boiling-point agent. The main objective of the presented...
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Termination functions for evolutionary path planning algorithm
PublikacjaIn this paper a study of termination functions (stop criterion) for evolutionary path planning algorithm is presented. Tested algorithm is used to determine close to optimal ship paths in collision avoidance situation. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. For the simulation purposes a close to real tested environment is created. Five...
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Fast Multi-Objective Optimization of Narrow-Band Antennas Using RSA Models and Design Space Reduction
PublikacjaComputationally efficient technique for multi-objective design optimization of narrow-band antennas is presented. In our approach, the corrected low-fidelity antenna model (obtained through coarse-discretization EM simulations) is enhanced using frequency scaling and response correction, sampled, and utilized to obtain a fast response surface approximation (RSA) antenna surrogate. The RSA model is constructed in the reduced design space....
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Multi-objective antenna design by means of sequential domain patching
PublikacjaA simple yet robust methodology for rapid multiobjective design optimization of antenna structures has been presented. The key component of our approach is sequential domain patching of the design space which is a stencil-based search that aims at creating a path that connects the extreme Pareto-optimal designs, obtained by means of single-objective optimization runs. The patching process yields the initial approximation of the...
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Optimization of the spindle speed during milling of large-sized structures with the use of technique of Experiment-Aided Virtual Prototyping
PublikacjaIn the paper are presented considerations concerning vibration suppression problems during milling of large-sized workpieces with the use of innovative method of matching the spindle speed of cutting tool. It depends on repeatable change of the spindle speed value as soon as the optimal vibration state of the workpiece approaches. The values of dominant “peaks” in the frequency spectra and the Root Mean Square (RMS) values of time...