Filtry
wszystkich: 526
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Wyniki wyszukiwania dla: SURROGATE MODELING, ANTENNA DESIGN
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Risk Assessment at Unsignalized Intersections Based on Human-Road-Environment-Vehicle System Applying Fuzzy Logic
PublikacjaThe constant increase in motorization level and traffic density increases risks due to dangerous situations for road participants. Therefore, assessing the accident level of road network elements has been an urgent task over the past decades. However, existing approaches mainly rely on traffic flow parameters and account for dynamic vehicle characteristics. The research aims to design a model accounting for uncertain factors (weather...
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Design advantages and analysis of a novel five-phase doubly-fed induction generator
PublikacjaPurpose – The purpose of this paper is to provide an analysis of the performance of a new five-phase doubly fed induction generator (DFIG). Design/methodology/approach – This paper presents the results of a research work related to fivephase DFIG framing, including the development of an analytical model, FEM analysis as well as the results of laboratory tests of the prototype. The proposed behavioral level analytical model is based...
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Variable-fidelity response feature surrogates for accelerated statistical analysis and yield estimation of compact microwave components
PublikacjaAccounting for manufacturing tolerances is an essential part of a reliable microwave design process. Yet, quantification of geometry and/or material parameter uncertainties is challenging at the level of full-wave electromagnetic (EM) simulation models. This is due to inherently high cost of EM analysis and massive simulations necessary to conduct the statistical analysis. Here, a low-cost and accurate yield estimation procedure...
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Development of a spray-ejector condenser for the use in a negative CO2 emission gas power plant
PublikacjaOne promising solution for developing low-emission power technologies is using gaseous fuel combustion in pure oxygen when the exhaust gas mixture is composed of H2O and CO2, and where CO2 is separated after steam condensation. The paper presents the results of computational analyses providing to the Spray-Ejector Condenser (SEC) development, which is one of the crucial components of the negative CO2 gas power plant (nCO2PP) cycle...
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SLIDING MODE-PID FUZZY CONTROLLER WITH A NEW REACHING MODE FOR UNDERWATER ROBOTIC MANIPULATORS
PublikacjaDesign of an accurate and robust controller is a challenging topic in an underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the...
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Design and distribution of air nozzles in the biomass boiler assembly
PublikacjaDue to energy crisis as well as increasing pollution of the environment, renewable energy sources usage increases all over the world. These facts encouraged authors to start research over developing a uniform biomass boiler calculation model. This paper presents a design of biomass boiler assembly created for ORC (Organic Rankine Cycle) unit since these systems could achieve strong position in energy industry....
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Comparison of state feedback and PID control of pressurizer water level in nuclear power plant
PublikacjaThe pressurizer water level control system in nuclear power plant with pressurized water reactor (PWR) is responsible for coolant mass balance. The main control goal is to stabilize the water level at a reference value and to suppress the effect of time-varying disturbances (e.g. coolant leakage in primary circuit pipeline system). In the process of PWR power plant operation incorrect water level may disturb pressure control or...
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Theoretical and Architectural Framework for Contextual Knowledge Bases
PublikacjaThe paper presents the approach aimed at building modularized knowledge bases in a systematic, context-aware way. The paper focuses on logical modeling of such knowledge bases, including an underlying SIM metamodel. The architecture of a comprehensive set of tools for knowledge-base systems engineering is presented. The tools enable an engineer to design, create and edit a knowledge base schema according to a novel context approach...
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Fluid–Structure Interaction methods for the progressive anatomical and artificial aortic valve stenosis
PublikacjaCardiovascular system diseases, as aortic valve stenosis, are the main cause of mortality and morbidity among patients. There is still a room for enhancement of the diagnostic and therapeutic procedures, which will lead to improvement of the treatment. One of the remedies are the computer tools to support the medical diagnoses and prostheses design. The development of a procedure for modeling the aortic valves: anatomical tricuspid...
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Broadband/Dual-band Metal-Mountable UHF RFID Tag Antennas: A Systematic Review. Taxonomy Analysis, Standards of Seamless RFID System Operation, Supporting IoT implementations, Recommendations and Future Directions
PublikacjaThe employment of broadband/dual-band ultra-high frequency (UHF) radio frequency identification (RFID) tag antennas contributes to the growth of RFID technology, with many potential implications, such as the increase of international trade, and reducing costs thereof. This study presents all reported articles on RFID tags for metal objects that can work seamlessly across different countries. Moreover, it addresses all available...
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On EM-driven size reduction of antenna structures with explicit constraint handling
PublikacjaSimulation-driven miniaturization of antenna components is a challenging task mainly due to the presence of expensive constraints, evaluation of which involves full-wave electromagnetic (EM) analysis. The recommended approach is implicit constraint handling using penalty functions, which, however, requires a meticulous selection of penalty coefficients, instrumental in ensuring optimization process reliability. This paper proposes...
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Predicting seismic response of SMRFs founded on different soil types using machine learning techniques
PublikacjaPredicting the Maximum Interstory Drift Ratio (M-IDR) of Steel Moment-Resisting Frames (SMRFs) is a useful tool for designers to approximately evaluate the vulnerability of SMRFs. This study aims to explore supervised Machine Learning (ML) algorithms to build a surrogate prediction model for SMRFs to reduce the need for complex modeling. For this purpose, twenty well-known ML algorithms implemented in Python software are trained...
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The influence of IT-competency dimensions on job satisfaction, knowledge sharing and performance across industries
PublikacjaPurpose – Technology makes knowledge management easier. Knowledge sharing is essential for organizational development. Job satisfaction fosters knowledge sharing. Hence, this study aims to develop an understanding of the mutual relationship between knowledge sharing and job satisfaction when both are predicted by information technology (IT)-competency dimensions such as IT-operations, IT-knowledge and IT-infrastructure in the context...
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Miniature reconfigurable antenna
PublikacjaThis work concerns the design of a miniature, low-profile reconfigurable antenna based on Huygens metamaterial sources for frequency f0 = 2.45 GHz. Two planar Huygens sources were designed consisting of near-field resonators. Sources are excited from a specially designed reconfigurable control system. Thanks to the two PIN diodes, the system can realize two cardioid radiation characteristics with...
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Control of the bridge span vibration with high coefficient passive damper. Theoretical consideration and application
PublikacjaThe research was carried out due to the problem of vibration on the lively pedestrian drawbridge across the Motlawa River in the city of Gdansk. In the design stage, the main span of the footbridge showed unfavorable dynamic properties, which may create a comfort problem for pedestrians. The first vertical bending eigenfrequency was recognized as 1.64 Hz. The original design of the footbridge was equipped with a driving cylinder...
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Do mistakes acceptance foster innovation? Polish and US cross-country study of tacit knowledge sharing in IT
PublikacjaAbstract Purpose – This study aims to understand and compare how the mechanism of innovative processes in the information technology (IT) industry – the most innovative industry worldwide – is shaped in Poland and the USA in terms of tacit knowledge awareness and sharing driven by a culture of knowledge and learning, composed of a learning climate and mistake acceptance. Design/methodology/approach – Study samples were drawn from...
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High Frequency Conducted Emission in AC Motor Drives Fed By Frequency Converters: Sources and Propagation Paths
PublikacjaProvides a concise and thorough reference for designing electrical and electronic systems that employ adjustable speed drives Electrical and electronic systems that employ adjustable speed drives are being increasingly used in present-day automation applications. They are considered by many application engineers as one of the most interfering components, especially in a contemporarily faced industrial environment. This book fills...
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Reduced-Cost Microwave Design Closure by Multi-Resolution EM Simulations and Knowledge-Based Model Management
PublikacjaParameter adjustment through numerical optimization has become a commonplace of contemporary microwave engineering. Although circuit theory methods are ubiquitous in the development of microwave components, the initial designs obtained with such tools have to be further tuned to improve the system performance. This is particularly pertinent to miniaturized structures, where the cross-coupling effects cannot be adequately accounted...
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The experimental evaluation and modeling of SBR removing nutrients under varied aeration conditions
PublikacjaSequencing batch reactors (SBR) are mainly characterized by sequential process phases of fill, react, settle, decant and idle periods that allow considerable flexibility in the design and operation in different conditions. This flexibility and the unique features of SBRs used to wastewater treatment by activated sludge systems operated in laboratory scale, allow not only conducting experiments for the standard conditions but also...
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Możliwości wydłużania krzywych przejściowych w układach geometrycznych torów
PublikacjaW pracy przedstawiono analizę problemu wydłużania krzywych przejściowych, wykorzystując do tego celu analityczną metodę projektowania. Podstawę analizy stanowiły obliczenia numeryczne przeprowadzone dla zestawu parametrów charakteryzujących standardowy układ geometryczny: krzywa przejściowa – łuk kołowy – krzywa przejściowa (w wersji niesymetrycznej). Ocenie poddano różnice rzędnych poziomych układu istniejącego oraz układu z...
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Impact of information systems (IS) infusion on Open Government Data (OGD) adoption
PublikacjaPurpose – This study aims to underline the possible influence of the moderator, information systems (IS) infusion, on Open Government Data (OGD) adoption and usage. Design/methodology/approach – Using the partial least squares-structural equation modeling methodological approach, the adapted unified theory of acceptance and use of technology (UTAUT) model has been used for understanding the role of themoderating variable, namely,...
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EVALUATION OF 3D MODEL OF REBAR FOR QUANTITATIVE PARAMETERS
PublikacjaThe construction industry practices and processes are evolving constantly, and with the emergence of Industry 4.0, the use of technologies is expanding. Construction progress monitoring is an essential project lifecycle process; project success and timely completion are linked with effective progress monitoring operations and adopted tools. In the domain of automated construction progress monitoring, 3D modeling techniques have...
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Application of the Flipped Learning Methodology at a Business Process Modelling Course – A Case Study
PublikacjaFlipped learning has been known for a long time, but its modern use dates back to 2012, with the publication of Bergmann and Saams. In the last decade, it has become an increasingly popular learning method. Every year, the number of publications on implementing flipped learning experiments is growing, just as the amount of research on the effectiveness of this educational method. The aim of the article is to analyze the possibilities...
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A compact spline-enhanced monopole antenna for broadband/multi-band and beyond UWB applications
PublikacjaIn this work, a compact monopole antenna for broadband/multi-band and beyond ultra- wideband (UWB) communication has been proposed. The structure is based on a spline-enhanced radiator with a broadband feed and a modified ground plane. Rigorous design optimization of the radiator has been performed in a two-stage framework where optimization of the structure with respect to electrical performance is followed by explicit miniaturization...
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Justifying the prolongation of the service life of the bearing structure of a tank car when using Y25 bogies
PublikacjaThis paper substantiates the use of Y25 bogies under tank cars in order to prolong their service life. The reported study has been carried out for a tank car with rated parameters, as well as the actual ones, registered during full-scale research. Mathematical modeling was performed to determine the basic indicators of the tank car dynamics. The differential equations of motion were solved by a Runge-Kutta method using the Mathcad...
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Model Management for Low-Computational-Budget Simulation-Based Optimization of Antenna Structures Using Nature-Inspired Algorithms
PublikacjaThe primary objective of this study is investigation of the possibilities of accelerating nature-inspired optimization of antenna structures using multi-fidelity EM simulation models. The primary methodology developed to achieve acceleration is a model management scheme which the level of EM simulation fidelity using two criteria: the convergence status of the optimization algorithm, and relative quality of the individual designs...
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Generation and Propagation of Nonlinear Waves in a Towing Tank
PublikacjaThe paper presents the results of the research focused on linear and nonlinear wave generation and propagation in a deepwater towing tank equipped with a single flap-type wavemaker of variable draft. The problem of wave generation and propagation has been theoretically formulated and solved by applying an analytical method; linear and nonlinear solutions were obtained. The linear solution has been verified experimentally. The...
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An Experimental and Numerical Analysis of Water Hammer Phenomenon in Slurries
PublikacjaThe analysis of slurry transportation in pressure pipelines is important both from practical and theoretical point of view. Due to the nature of the medium, the number of problems arising in the course of design, operation, measurements and mathematical modeling is much higher compared to the cases where the flowing liquid is homogeneous. The equations describing the flow are more complex, and higher number of the parameters is...
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Modeling of entrained flow steam gasification of sewage sludge
PublikacjaProper management of sewage sludge becomes increasingly problematic due to legal requirements aiming at diminishing environmental impact, as well as rationalizing the utilization from the point of view of logistics. Steam gasification of sewage sludge can result in very good quality of the producer gas. So far, the works have been focused on the gasification in fixed bed gasifiers. However, this does not allow to take full advantage...
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Modeling lignin extraction with ionic liquids using machine learning approach
PublikacjaLignin, next to cellulose, is the second most common natural biopolymer on Earth, containing a third of the organic carbon in the biosphere. For many years, lignin was perceived as waste when obtaining cellulose and hemicellulose and used as a biofuel for the production of bioenergy. However, recently, lignin has been considered a renewable raw material for the production of chemicals and materials to replace petrochemical resources....
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Modelowanie matematyczne górnej sieci trakcyjnej dla potrzeb diagnostyki odbieraków prądu
PublikacjaGórna sieć trakcyjna jest obecnie najbardziej skutecznym sposobem zasilania kolejowych pojazdów elektrycznych. Wzrost prędkości pojazdów zwiększa pobór mocy i wymaga zapewnienia właściwej współpracy odbieraków prądu pojazdów z siecią jezdną. Metody modelowania i projektowania wspomaganego komputerowo dla górnej sieci trakcyjnej są obecnie na całym świecie szeroko rozwijane. W artykule przedstawiono nowy model matematyczny elementów...
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Badanie dynamiki platform pływających morskich turbin wiatrowych z zastosowaniem metod numerycznej mechaniki płynów
PublikacjaPraca dotyczy badania ruchu platform pływających pod morskie turbiny wiatrowe. Przedstawiono w niej główne metody obliczeń i przedyskutowano ich zastosowanie. Na przykładzie koncepcji konstrukcji 3-kolumnowej platformy typu Spar przedstawiono metodykę wykonywania obliczeń z zastosowaniem programu AQWA opartego na metodzie dyfrakcyjnej, rozszerzonego o współczynniki wynikające z lepkości wyznaczone za pomocą obliczeń RANSE-CFD....
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Exploring the Beam Squint Effects on Reflectarray Perfromance: A Comprehensive Analysis of the Specular and Scattered Reflection of the Unit Cell
PublikacjaIn this article, the phenomena of beam deviation in reflectarray is discussed. The radiation pattern of the unit cell, which plays a vital role in shaping the beam of the reflectarray, is analyzed by considering undesired specular and scattered reflections. These unwanted reflections adversely affect the pattern of the single unit cell, thereby reducing the overall performance of the reflectarray. To conduct our investigations,...
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Online brand communities’ contribution to digital business models
PublikacjaAbstract Purpose – There is limited research examining social drivers and mediators of online brand community identification in the context of business models development. This study aims to identify them behind the social mechanisms and present essential factors which should be applied in business models to foster value co-creation. Design/methodology/approach – Data were collected from a convenience sample of 712 cases gathered among...
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Eu2Mg3Bi4: Competing Magnetic Orders on a Buckled Honeycomb Lattice
PublikacjaThe honeycomb lattice and its derived variants provide information on modeling and designing quantum magnets. A novel magnetic material, Eu2Mg3Bi4, which stabilizes in a previously unknown buckled honeycomb lattice, was discovered by high-pressure and high-temperature methods. We report here on the synthesis exploration of pure single crystals, structural determination of the buckled honeycomb lattice of europium moments, and experimental observation...
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A new open-source software developed for numerical simulations usingdiscrete modeling methods
PublikacjaThe purpose of this work is to present the development of an open-source software based on a discrete description of matter applied to study the behavior of geomaterials. This software uses Object Oriented Programming techniques, and its methodology design uses three different methods, which are the Discrete Element Method (DEM) [F. Donzé, S.A. Magnier, Formulation of a three-dimensional numerical model of brittle behavior, Geophys....
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Optimization-Based High-Frequency Circuit Miniaturization through Implicit and Explicit Constraint Handling: Recent Advances
PublikacjaMiniaturization trends in high-frequency electronics have led to accommodation challenges in the integration of the corresponding components. Size reduction thereof has become a practical necessity. At the same time, the increasing performance demands imposed on electronic systems remain in conflict with component miniaturization. On the practical side, the challenges related to handling design constraints are aggravated by the...
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Overview of planar antenna loading metamaterials for gain performance enhancement: the two decades of progress
PublikacjaMetamaterials (MTMs) are artificially engineered materials with unique electromagnetic properties not occurring in natural materials. MTMs have gained considerable attention owing to their exotic electromagnetic characteristics such as negative permittivity and permeability, thereby a negative refraction index. These extraordinary properties enable many practical applications such as super-lenses, and cloaking technology, and are...
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Mathematical approach to design 3D scaffolds for the 3D printable bone implant
PublikacjaThis work demonstrates that an artificial scaffold structure can be designed to exhibit mechanical properties close to the ones of real bone tissue, thus highly reducing the stress-shielding phenomenon. In this study the scan of lumbar vertebra fragment was reproduced to create a numerical 3D model (this model was called the reference bone sample). New nine 3D scaffold samples were designed and their numerical models were created....
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Synthesis and biological evaluation of fluorinated N-benzoyl and N-phenylacetoyl derivatives of 3-(4-aminophenyl)-coumarin-7-O-sulfamate as steroid sulfatase inhibitors
PublikacjaIn the present work, we report convenient methods for the synthesis of 3-(4-aminophenyl)-coumarin-7-O-sulfamate derivatives N-acylated with fluorinated analogues of benzoic or phenylacetic acid as steroid sulfatase (STS) inhibitors. The design of these potential STS inhibitors was supported by molecular modeling techniques. Additionally, computational docking methods were used to determine the binding modes of the synthesized inhibitors...
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Workers, Firms and Task Heterogeneity in International Trade Analysis: An Example of Wage Effects of Trade Within GVC.
PublikacjaObjective: The main aim of this article is to present how the heterogeneity of workers, firms, and tasks can be incorporated into empirical international trade analysis. In particular, we provide an empirical example in which we aim to quantify the reliance on foreign value added (FVA) within Global Value Chains (GVC) on wages. Research Design & Methods: We estimate a Mincerian wage model augmented with a measure of foreign value...
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Multi-objective optimization of water quality, pumps operation, and storage sizing of water distribution systems
PublikacjaA multi-objective methodology utilizing the Strength Pareto Evolutionary Algorithm (SPEA2) linked to EPANET for trading-off pumping costs, water quality, and tanks sizing of water distribution systems is developed and demonstrated. The model integrates variable speed pumps for modeling the pumps operation, two water quality objectives (one based on chlorine disinfectant concentrations and one on water age), and tanks sizing cost...
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Personal branding of artists and art-designers: necessity or desire?
PublikacjaPurpose Personal branding becomes a new in-demand skill for all professionals today. To be well-known helps to achieve success in the networked business environment. Personal relationships and a good reputation in the reality of network economy help young artists and art designers move up the career ladder. This paper aims to discuss a problem of artists who often find it difficult to define their artistic and self-distinction...
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The impact of brand communication on brand equity through Facebook
PublikacjaPurpose The purpose of this study is to fill the gap in the discussion of the ways in which firm-created and user-generated social media brand communication impacts consumer-based brand equity metrics through Facebook. Design/methodology/approach We evaluated 302 data sets that were generated through a standardized online-survey to investigate the impact of firm-created and user-generated social media brand communication on brand...
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Estimation and modeling hydrolysis of slowly biodegradable substrate based on the batch respirometric tests in activated sludge systems
PublikacjaNowadays, appropriate determination of chemical oxygen demand (COD) fractionation together with degradation kinetics of organic compounds have a prime importance on the design and operation of activated sludge systems. Batch respirometric tests based on the oxygen uptake rates (OUR) and corresponding COD is accepted method to reflect the consumption of biodegradable substrates. The influence of the readily biodegradable (Ss) fraction...
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The advanced monitoring as a key factor for appropriate optimization and control of full-scale activated sludge systems – case study Debogorze WWTP.
PublikacjaComputer simulation has become a helpful tool in wastewater treatment systems performance and effectiveness analysis. Advanced monitoring, by using appropriate software, enables to create a mathematical model of a real wastewater treatment plant (WWTP), run a simulation and subsequently interpret results under various conditions. An operation of WWTP is usually controlled by global parameters such as flow, solids retention time,...
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The power of personal brand authenticity and identification: top celebrity players’ contribution to loyalty toward football
PublikacjaPurpose: In the current era of fake news, illusions, manipulations, and other artificial attributes of virtuality and reality, authenticity is a virtue that people highly appreciate. This study examines the influence of the personal brand authenticity of top football players on loyalty to the football discipline in general, via the mediation of personal brand identification. Design: Based on data collected from a convenience sample...
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SEDIMENT DEPOSITION IN RESERVOIRS IN URBAN BASIN
PublikacjaIn recent years Gdańsk had sustained economic and social losses due to severe flash floods coming down from moraine hills. The first flood occurred in July 2001 and the second in July 2016. Both events were caused by intense and long rainfall characterized by different from each other rain intensity in time. Among other Gdansk’s streams the Oliwski Stream has the most extended flood protection system consist of 15 small retention...
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Leadership, culture, intellectual capital and knowledge processes for organizational innovativeness across industries: the case of Poland
PublikacjaPurpose – This study aims to present the overview of intellectual capital creation micro-mechanisms concerning formal and informal knowledge processes. The organizational culture, transformational leadership and innovativeness are also included in the investigation as ascendants and consequences of the focal relation of intellectual capital and knowledge processes. Design/methodology/approach – Based on a sample of 1,418 Polish...
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The particle method for simulation of self-organization phenomena
PublikacjaThe aim of the work was to design, implement, and use, in a number of experiments, an abstract software environment (an artificial world)suitable for modelling systems consisting of many moving and interactingobjects distributed in space. The environment, named DigiHive, is directed towards modeling of complex systems manifested by processes of self-organization, self-reproduction and self modifications. The environment is mainly...