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Wyniki wyszukiwania dla: OPTIMAL THRUST ALLOCATION
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Separability in terms of a single entanglement witness
PublikacjaThe separability problem is formulated in terms of a characterization of a single entanglement witness. More specifically, we show that any (in general multipartite) state rho is separable if and only if a specially constructed entanglement witness W-rho is weakly optimal, i.e., its expectation value vanishes on at least one product vector. Interestingly, the witness can always be chosen to be decomposable. Our result changes the...
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MACHINE VISION DETECTION OF THE CIRCULAR SAW VIBRATIONS
PublikacjaDynamical properties of rotating circular saw blades are crucial for both production quality and personnel safety. This paper presents a novel method for monitoring circular saw vibrations and deviations. A machine vision system uses a camera and a laser line projected on the saw’s surface to estimate vibration range. Changes of the dynamic behaviour of the saw were measured as a function of the rotational speed. The critical rotational...
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Optimization of clamping stiffness during milling of high-dimensional structures with the use of techniques of experiment – aided virtual prototyping
PublikacjaThe subject of this paper is a method of searching for conditions of minimizing the vibration level of a tool-high dimensional flexible workpiece, at unchangeable technological parameters of the machining process. It depends on repeatable change of the values of the stiffness coefficients as soon as an optimal vibration state of the workpiece approaches. There are assessed the values of dominant ”peaks” in the frequency spectra...
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MEAN SHIFT BASED SEGMENTATION FOR BLEEDING REGIONS IN ENDOSCOPIC VIDEOS
PublikacjaWith a set of 38 manually marked bleeding regions form endoscopic videos, the authors attempted to find an optimal image segmentation method for reproducing doctor’s markup. Mean shift segmentation combined with HSV histogram segmentation were used as a segmentation method, which was then optimized by tuning the parameters of the method using global optimization algorithm. A target function for measuring the quality of segmentation was...
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A simple approach to heat exchanger sizing optimisation by means of entrophy generation minimisation
PublikacjaIn the paper an attempt is presented to find the method of optimization of microtube diameter with respect to optimal thermal-hydraulic conditions in the single-phase shell-and-tube heat exchangers. The approach is based on consideration of pumping power at the condition of maximum heat transfer by the heat exchanger tube system. In the optimization method the tube diameter is first specified and then appropriate calculations are...
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Numerical and experimental investigation of thermal convection near electric devices with vertical channels
PublikacjaThis paper presents the results of numerical and experimental investigation of thermal convection near heat emitting surfaces of an electric device. For the intensification of thermal convection, special vertical channels were formed near the heat emitting surfaces of the device. An experimental test has proved that there is an optimal length of the channels – thermal convection is the most intensive then. Air velocity vectors...
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Infinite chromatic games
PublikacjaIn the paper we introduce a new variant of the graph coloring game and a new graph parameter being the result of the new game. We study their properties and get some lower and upper bounds, exact values for complete multipartite graphs and optimal, often polynomial-time strategies for both players provided that the game is played on a graph with an odd number of vertices. At the end we show that both games, the new and the classic...
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The impact of air humidity on the operation of proton exchange membrane fuel cells determined using dynamic electrochemical impedance spectroscopy
PublikacjaThis paper describes the changes in the fuel cell impedance across a range of current loads and humidity changes. The changes of each equivalent circuit parameters representing specific processes occurring in fuel cells, as a function of humidity and current changes, were determined. Within the combined scope of current and humidity, the optimal working conditions of the cells were determined, corresponding to the lowest impedance...
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Dekodowanie kodów iterowanych z użyciem sieci neuronowej
PublikacjaNadmiarowe kody iterowane są jedną z prostych metod pozyskiwania długich kodów korekcyjnych zapewniających dużą ochronę przed błędami. Jednocześnie, chociaż ich podstawowy iteracyjny dekoder jest prosty koncepcyjnie oraz łatwy w implementacji, to nie jest on rozwiązaniem optymalnym. Poszukując alternatywnych rozwiązań zaproponowano, przedstawioną w pracy, strukturę dekodera tego typu kodów wspomaganą przez sieci neuronowe. Zaproponowane...
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Optimization of Saccharification Conditions of Lignocellulosic Biomass under Alkaline Pre-Treatment and Enzymatic Hydrolysis
PublikacjaPre-treatment is a significant step in the production of second-generation biofuels from waste lignocellulosic materials. Obtaining biofuels as a result of fermentation processes requires appropriate pre-treatment conditions ensuring the highest possible degree of saccharification of the feed material. An influence of the following process parameters were investigated for alkaline pre-treatment of Salix viminalis L.: catalyst concentration...
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Multi-fidelity aerodynamic design trade-off exploration using point-by-point Pareto set identification
PublikacjaAerodynamic design is inherently a multi-objective optimization (MOO) problem. Determining the best possible trade-offs between conflicting aerodynamic objectives can be computationally challenging when carried out directly at the level of high-fidelity computational fluid dynamics simulations. This paper presents a computationally cheap methodology for exploration of aerodynamic design trade-offs. In particular, point-by-point...
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Thermosensitive composite based on agarose and chitosan saturated with carbon dioxide. Preliminary study of requirements for production of new CSAG bioink.
PublikacjaThis study introduces a method for producing printable, thermosensitive bioink formulated from agarose (AG) and carbon dioxide-saturated chitosan (CS) hydrogels. The research identified medium molecular weight chitosan as optimal for bioink production, with a preferred chitosan hydrogel content of 40–60 %. Rheological analysis reveals the bioink's pseudoplastic behavior and a sol-gel phase transition between 27.0 and 31.5 °C. The...
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Satellite Image Classification Using a Hierarchical Ensemble Learning and Correlation Coefficient-Based Gravitational Search Algorithm
PublikacjaSatellite image classification is widely used in various real-time applications, such as the military, geospatial surveys, surveillance and environmental monitoring. Therefore, the effective classification of satellite images is required to improve classification accuracy. In this paper, the combination of Hierarchical Framework and Ensemble Learning (HFEL) and optimal feature selection is proposed for the precise identification...
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Determinants of the primary stability of cementless acetabular cup implants: A 3D finite element study
PublikacjaPrimary stability of cementless implants is crucial for the surgical success and long–term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press–fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference...
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Aerodynamic Shape Optimization for Delaying Dynamic Stall of Airfoils by Regression Kriging
PublikacjaThe phenomenon of dynamic stall produce adverse aerodynamic loading which can adversely affect the structural strength and life of aerodynamic systems. Aerodynamic shape optimization (ASO) provides an effective approach for delaying and mitigating dynamic stall characteristics without the addition of auxiliary system. ASO, however, requires multiple evaluations time-consuming computational fluid dynamics models. Metamodel-based...
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Multi-objective optimization for assessment of topological modification in UWB antennas
PublikacjaThis paper addresses an issue of systematic and rigorous assessment of effects of topological modifications on the performance of compact UWB antennas. Application of fast surrogate-assisted multi-objective optimization procedures allows us for obtaining, in a practically acceptable timeframe, a set of designs representing the best possible trade-offs between conflicting objectives (here, antenna size minimization and reduction...
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A Special Section on Intelligent User Interfaces in Healthcare (IUIH)
PublikacjaA concept of interface has evolved from the first appearance in the form of a command line interface to the established use of direct manipulation or WIMP (windows, icons, menus and pointing) interfaces in nearly all applications. Intelligent user interfaces (IUI) form a subfield of Human-Computer Interaction research. Optimal human-computer interactions are defined as ones where users are able to perform complex tasks more quickly...
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Expedited Multi-Objective Design Optimization of Miniaturized Microwave Structures Using Physics-Based Surrogates
PublikacjaIn this paper, a methodology for fast multi-objective design optimization of compact microwave circuits is presented. Our approach exploits an equivalent circuit model of the structure under consideration, corrected through implicit and frequency space mapping, then optimized by a multi-objective evolutionary algorithm. The correction/optimization of the surrogate is iterated by design space confinement and segmentation based on...
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Rainscreen panels deformations mods
PublikacjaIn rainscreen panels designing simplified calculation models are used. For plate computation simply supported panels or panels with fixed edges are commonly used. Such approximations are subjected to large errors that lead to inefficient rainscreen panels design. In order to develop a method for determining the optimal geometry of the rainscreen panels, that would take into consideration the real stiffness of both continuous and...
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Computational intelligence methods in production management
PublikacjaThis chapter presents a survey of selected computational intelligence methods used in production management. This group of methods includes, among others, approaches based on the artificial neural networks, the evolutionary algorithms, the fuzzy logic systems and the particle swarm optimization mechanisms. From the abovementioned methods particularly noteworthy are the evolutionary and the particle swarm algorithms, which are successfully...
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SYNTHETIZED MEMBRANES FOR ULTRASOUND-ASSISTED SOLVENT EXTRACTION OF POROUS MEMBRANE PACKED SOLID SAMPLES.
PublikacjaMembranes are becoming more and more popular in analytical chemistry, which is why they are used, among others, in extraction processes. Therefore, this work focuses on the process of synthesis PVDF membranes and its optimization. The obtained membranes were used as bags for the phthalate extraction in disposable diapers for babies. Extraction was accomplished by method ultrasound-assisted solvent extraction of porous PVDF membrane...
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Multi-objective Tabu-based Differential Evolution for Teleportation of Smart Virtual Machines in Private Computing Clouds
PublikacjaWe propose a multi-objective approach for using differential evolution algorithm with tabu search algorithm as an additional mutation for live migration (teleportation) of virtual machines. This issue is crucial in private computing clouds. Teleportation of virtual machines is supposed to be planned to determine Pareto-optimal solutions for several criteria such as workload of the bottleneck host, communication capacity of the...
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Reconfiguring Minimum Dominating Sets in Trees
PublikacjaWe provide tight bounds on the diameter of γ-graphs, which are reconfiguration graphs of the minimum dominating sets of a graph G. In particular, we prove that for any tree T of order n ≥ 3, the diameter of its γ-graph is at most n/2 in the single vertex replacement adjacency model, whereas in the slide adjacency model, it is at most 2(n − 1)/3. Our proof is constructive, leading to a simple linear-time algorithm for determining...
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Performance Analysis of Convolutional Neural Networks on Embedded Systems
PublikacjaMachine learning is no longer confined to cloud and high-end server systems and has been successfully deployed on devices that are part of Internet of Things. This paper presents the analysis of performance of convolutional neural networks deployed on an ARM microcontroller. Inference time is measured for different core frequencies, with and without DSP instructions and disabled access to cache. Networks use both real-valued and...
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Physicochemical Properties and Application of Silica-Doped Biochar Composites as Efficient Sorbents of Copper from Tap Water
PublikacjaThis article concerns research on new sorption materials based on silica-doped activated carbon. A two-stage synthesis involved pyrolysis of plant material impregnated in a water glass solution , followed by hydrothermal activation of the pyrolysate in KOH solution. The resulting composite can be used as a sorbent in drinking water filters. The proposed method of synthesis enables the design of materials with a surface area...
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Discrete identification of continuous non-linear and non-stationary dynamical systems that is insensitive to noise correlation and measurement outliers
PublikacjaThe paper uses specific parameter estimation methods to identify the coefficients of continuous-time models represented by linear and non-linear ordinary differential equations. The necessary approximation of such systems in discrete time in the form of utility models is achieved by the use of properly tuned `integrating filters' of the FIR type. The resulting discrete-time descriptions retain the original continuous parameterization...
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Development of a new green analytical methodology for the determination of phthalates in single-use babies diapers using ultrasound-assisted extraction and polypropylene porous membrane
PublikacjaA green extraction strategy was developed and utilized for the extraction and determination of phthalates. The extraction is based on ultrasound-assisted extraction and a polypropylene porous membrane. The Box-Behnken model was performed to optimize the extraction condition. The optimal extraction conditions are 5.5 mL of ethyl acetate, 10 min of extraction time and 55 C for extraction temperature. The developed green extraction...
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On the hat problem on a graph
PublikacjaThe topic of this paper is the hat problem in which each of n players is uniformly and independently fitted with a blue or red hat. Then everybody can try to guess simultaneously his own hat color by looking at the hat colors of the other players. The team wins if at least one player guesses his hat color correctly, and no one guesses his hat color wrong; otherwise the team loses. The aim is to maximize the probability of winning....
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Metaheuristic algorithms for optimization of resilient overlay computing systems
PublikacjaThe idea of distributed computing systems has been gaining much interest in recent years owing to the growing amount of data to be processed for both industrial and academic purposes. However, similar to other systems, also distributed computing systems are vulnerable to failures. Due to strict QoS requirements, survivability guarantees are necessary for provisioning of uninterrupted service. In this article, we focus on reliability...
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Efficient production of Staphylococcus simulans lysostaphin in a benchtop bioreactor by recombinant Escherichia coli.
PublikacjaLysostaphin is an enzyme with bactericidal activity against Staphylococcus aureus and other staphylococcal species. In spite of many advantages and promising results of preliminary research, the enzyme is still not widely used in medicine, veterinary or as a food preservative. One of the most important factors limiting application of the enzyme in clinical or technological practice is the high costs of its production. In the present...
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Greedy Multipoint Model-Order Reduction Technique for Fast Computation of Scattering Parameters of Electromagnetic Systems
PublikacjaThis paper attempts to develop a new automated multipoint model-order reduction (MOR) technique, based on matching moments of the system input–output function, which would be suited for fast and accurate computation of scattering parameters for electromagnetic (EM) systems over a wide frequency band. To this end, two questions are addressed. Firstly, the cost of the wideband reduced model generation is optimized by automating a...
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Distributed Evacuation in Graphs with Multiple Exits
PublikacjaWe consider the problem of efficient evacuation using multiple exits. We formulate this problem as a discrete problem on graphs where mobile agents located in distinct nodes of a given graph must quickly reach one of multiple possible exit nodes, while avoiding congestion and bottlenecks. Each node of the graph has the capacity of holding at most one agent at each time step. Thus, the agents must choose their movements strategy...
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Multi-objective optimization of the cavitation generation unit structure of an advanced rotational hydrodynamic cavitation reactor
PublikacjaHydrodynamic cavitation (HC) has been widely considered a promising technique for industrial-scale process intensifications. The effectiveness of HC is determined by the performance of hydrodynamic cavitation reactors (HCRs). The advanced rotational HCRs (ARHCRs) proposed recently have shown superior performance in various applications, while the research on the structural optimization is still absent. The present study, for the...
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Lateral forces determine dimensional accuracy of the narrow‑kerf sawing of wood
PublikacjaThe shrinking global forest area limits the supply of industrially usable raw resources. This, in combination with the ever‑increasing consumption of timber due to population growth can lead to the lack of a positive balance between the annual volumetric growth and consumption of wood. An important innovation toward increasing environmental and economic sustainability of timber production is to reduce the volume of wood residues...
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Shared processor scheduling of multiprocessor jobs
PublikacjaWe study a problem of shared processor scheduling of multiprocessor weighted jobs. Each job can be executed on its private processor and simultaneously on possibly many processors shared by all jobs. This simultaneous execution reduces their completion times due to the processing time overlap. Each of the m shared processors may charge a different fee but otherwise the processors are identical. The goal is to maximize the total...
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Technical and Economic Analysis of the Implementation of Selected Variants of Road Investment
PublikacjaThe aim of the article is to analyze three variants of modernization and reconstruction of a road intersection, which in practice is the cause of numerous collisions and accidents. Detailed design solutions are presented for them. The aim of the analyses is to indicate an effective solution that, taking into account technical modifications of the road system elements, will ensure the functionality of the road system to the highest...
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Integrated algorithm for selecting the location and control of energy storage units to improve the voltage level in distribution grids
PublikacjaThis paper refers to the issue that mainly appears in distribution grids, where renewable energy sources (RES) are widely installed. In such grids, one of the main problems is the coordination of energy production time with demand time, especially if photovoltaic energy sources are present. To face this problem, battery energy storage units (ESU) can be installed. In recent years, more and more attention has been paid to optimizing...
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Longitudinal Motion Due to Action of Tunnel Thrusters
PublikacjaTunnel thrusters are propulsion and active control devises that provide a side force, or transverse thrust, to support mooring operations or position keeping. They shorten the time of manoeuvring, reduce the cost of towage and since inception, manoeuvrability specifically in ports has become a lot easier. Tunnel thrusters can either be operated manually or with the help of Dynamic Positioning systems which makes it even more efficient. Theoretically,...
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The effect of the exposure-in-oil on the contact of the polymers forming sliding layers in hydrodynamic bearings. Wpływ ekspozycji w oleju na kąt zwilżania polimerów stosowanych na warstwy ślizgowe w łożyskach hydrodynamicznych.
PublikacjaPolimery stosowane jako warstwy ślizgowe w hydrodynamicznych łożyskach wzdłużnych to zazwyczaj tworzywa termoplastyczne charakteryzujące się relatywnie wysokimi wartościami kątów zwilżania w porównaniu z metalami. Metale, w tym również Babbitt czy inne stopy łożyskowe, cechują niskie wartości kątów zwilżania. Im niższy kąt, tym powierzchnia lepiej się zwilża. Tworzywa sztuczne wykorzystywane w węzłach tribologicznych mających zapewnić...
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Ring thruster - a preliminary optimisation study
PublikacjaThe ring thruster is a new type of propeller, for which there is no experimental data to verify analytical design calculations. A significant feature of the ring thruster is the absence of a shaft. Propeller blades are mounted to the ring rotating inside the housing, which has the shape of a nozzle. For this reason the ring thruster is closest, with respect to both the construction and principle of operation, to the Kort nozzle...
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Analiza techniczno-ekonomiczna rozwiązań rewitalizacyjnych zabytkowego mostu w Tczewie
PublikacjaPrzykłady koncepcji odbudowy przyczółka zachodniego zabytkowego mostu przez rzekę Wisłę w Tczewie wraz z zespołem bramnym. Ocena propozycji trzech rozwiązań rewitalizacyjnych mostu i wybór optymalnego pod względem finansowym i technologicznym. Czas i koszty budowy oraz wierność odbudowy zespołu bramnego mostu jako kryteria optymalizacji. Analiza w celu pozyskania środków finansowych potrzebnych na odbudowę, ale także adaptację...
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On autoregressive spectrum estimation using the model averaging technique
PublikacjaThe problem of estimating spectral density of a nonstationary process satisfying local stationarity conditions is considered. The proposed solution is a two step procedure based on local autoregressive (AR) modeling. In the first step Bayesian-like averaging of AR models, differing in order, is performed. The main contribution of the paper is development of a new final-prediction-error-like statistic, which can be used to select...
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Multiple-Input Multiple-Output Technique for Underwater Acoustic Communication System
PublikacjaThe performance of an underwater acoustic communication (UAC) system is limited due to tough propagation conditions in the UAC channel. Multiple-Input Multiple-Output (MIMO) technique can improve the reliability of the data transmission system, increase its speed, increase its range, and reduce the energy consumption. The paper presents an implementation method of MIMO technique in the form of coding the Space-Time Block Code and...
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A Point Set Connection Problem for Autonomous Mobile Robots in a Grid
PublikacjaConsider an orthogonal grid of streets and avenues in a Manhattan-like city populated by stationary sensor modules at some intersections and mobile robots that can serve as relays of information that the modules exchange, where both module-module and module-robot communication is limited to a straight line of sight within the grid. The robots are oblivious and move asynchronously. We present a distributed algorithm that, given...
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Solving the Problem of Dynamic Adaptability of Artificial Intelligence Systems that Control Dynamic Technical Objects
PublikacjaThis paper investigates the increase in the response speed and stability of artificial intelligence systems that control dynamic technical objects. The problem of calculating the optimal time of switching an artificial intelligence system between software classes by the criterion of the rigidity degree of the model of a control object is considered. The solution of this problem is proposed for the general case of the control object...
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Local Texture Pattern Selection for Efficient Face Recognition and Tracking
PublikacjaThis paper describes the research aimed at finding the optimal configuration of the face recognition algorithm based on local texture descriptors (binary and ternary patterns). Since the identification module was supposed to be a part of the face tracking system developed for interactive wearable computer, proper feature selection, allowing for real-time operation, became particularly important. Our experiments showed that it is...
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Nano-structured Pt embedded in the acidic salts of heteropolymolybdate matrices: MS XAFS study
PublikacjaMultiple-scattering extended X-ray absorption fine structure (MS EXAFS) study combined with TEM and XRD analysis of a novel Pt-based catalyst operating at low temperature fuel cells (FCs) is presented. Innovation in the case of the considered catalyst resides in the use of a porous inorganic matrix of acidic heteropolymolybdate salts as a catalyst support. Obtained results show the relation between the matrix composition and the...
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Impact of Initial Population on Evolutionary Path Planning Algorithm
PublikacjaIn this paper an impact of initial population on evolutionary path planning algorithm is presented. Tested algorithm is used to determine close to optimal shippaths 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. Four tests are performed....
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A reliable synthesis of discrete-time H-inf control. Part I: basic theorems and J-lossless conjugators
PublikacjaThe paper gives a basis for solving many problems of numerically reliable synthesis of sub-optimal discrete-time control in H-inf. The approach is based on J-lossless factorisation of the delta-domain chain-scattering description of continuous-time plants being controlled. Relevant properties of poles and zeroes of chain-scattering models are given. Necessary and sufficient conditions for the existence of stabilising J-lossless...
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Theoretical analysis of the cable-stayed bridge over brda river in Bydgoszcz
PublikacjaThe topic of this article is the numerical analysis carried out for the cable-stayed tram (road) bridge over Brda river in Bydgoszcz. The goal of numerical studies was the verification of project assumptions and construction solutions elaborated by the autonomous team. The bridge calculations were conducted on three independent FEM models The internal forces and the elements effort under different loading schemes were examined....