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Search results for: hearing loss
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Common-Mode Voltage and Bearing Currents in PWM Inverters: Causes, Effects and Prevention
PublicationIn modern induction motor drives an increase of transistors' switching frequency and a decrease of switching times are the sources of some serious problems. The high dv/dt and the common mode voltage generated by the inverter PWM control results in the appearances of bearing currents, shaft voltages, motor terminal overvoltages, the decrease of motor efficiency, and electromagnetic interference. The aspects of common mode (CM)...
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Standing Waves and Acoustic Heating (or Cooling) in Resonators Filled with Chemically Reacting Gas
PublicationStanding waves and acoustic heating in a one-dimensional resonator filled with chemically reacting gas, is the subject of investigation. The chemical reaction of A ! B type, which takes place in a gas, may be reversible or not. Governing equations for the sound and entropy mode which is generated in the field of sound are derived by use of a special mathematical method. Under some conditions, sound waves propagating in opposite...
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Improving the accuracy of bearing in active sonar with cylindrical array using spectrum estimation.
PublicationThe articles presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. Based on a known spatial spectrum estimation technique, the method has been successfully used in linear array systems. Its accuracy of bearing is satisfactory and ensures a relatively low computational effort. The article discusses certain simplifications and assumptions to adapt the spatial spectrum estimation technique...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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Optical flow method for measuring deformation of soil specimen subjected to torsional shearing
PublicationIn this study optical flow method was used for soil small deformation measurement in laboratory tests. The main objective was to observe how the deformation distributes along the whole height of cylindrical soil specimen subjected to torsional shearing (TS test). The experiments were conducted on dry non-cohesive soil specimens under two values of isotropic pressure. Specimens were loaded with low-amplitude cyclic torque to analyze...
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DESIGN AND THEORETICAL ANALYSIS OF A PROTOTYPE TILTING-PAD RADIAL BEARING WITH ADJUSTABLE CLEARANCE
PublicationThe 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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Ecological bearing systems for water turbines – research and development at Gdansk University of Technology
PublicationIncreasing requirements for environmental protection make it necessary to introduce new materials and designs. Hydroelectric power plants operating in direct contact with water reservoirs and rivers are potentially endangering water cleanliness, hence they should also be modernized in the way minimizing the environmental hazards. A lot of progress in this field has been achieved in last decades, but still there is much work to...
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Effect of manufacturing errors of the pad sliding surface on the performance of the hydrodynamic thrust bearing
PublicationIn the present study, investigation of the effect of manufacturing errors on the performance of large tilting pad thrust bearings has been performed, following a CFD-based Thermohydrodynamic analysis of a single pad. A 3D model has been generated, including the pad, the lubricant film and the corresponding part of the collar. The pad has been assumed to be deformed about the pivot point, due to thrust loading. Manufacturing errors...
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BACTERIAL INACTIVATION VIA LASER-DRIVEN GOLD NANOPARTICLE HEATING: SIMULATION AND ANALYSIS
PublicationThis study utilizes CFD technique to simulate the inactivation of E. coli bacteria within a microfluidic chamber, employing gold nanoparticles irradiated by a laser beam. Employing a single-phase model, the presence of bacteria is considered by treating thermal properties in the governing equations as effective, combining those of water and bacteria using established correlations from scientific literature. The conversion of light...
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Heating caused by a non periodic ultrasound. Theory and calculations on pulse and stationary sources.
PublicationPrzedstawiono teorię ewolucji ogrzewania na skutek przejścia fali akustycznej każdego typu. Przedyskutowano obliczenia na podstawie nowych wzorów dla fali impulsowej i uderzeniowej. Wzory zgadzają się z klasycznymi w wypadku fal okresowych.
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Effects of loading pattern and lubricant pressure influence on bearing alloy fatigue characteristics
PublicationOpisano wyniki testów zmęczeniowych przeprowadzonych dla stopu łożyskowego AlSn (11,3 Cu 1,2) osadzonego na taśmie stalowej. Doświadczalnie określono wartości obciążeń niszczących dla różnych warunków obciążenia: dla obciążeń zginających wahadłowych, dla obciążeń zginających wahadłowych przy równoczesnym działaniu słabego lub zmiennego ciśnienia w komorze olejowej.
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Designing learning-skills towards industry 4.0
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Concentration of saline wastewater from the production of heparin
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Institutionalization of knowledge sharing in a software development organization
PublicationZaproponowano podejście modelowe do problemu wymiany wiedzy. Omówiono implementację modelu na przykładzie instytucji zajmującej się produkcja oprogramowania komputerowego.
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The State and Critical Assessment of the Sharing Economy in Europe
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The Sharing Economy in Europe: From Idea to Reality
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Temperature measurements in monitoring of large thrust bearings
PublicationW pracy przedstwiono krytyczną analizę aktualnych metod diagnostyki dużych hydrodnamicznych łożysk wzdłużnych hydrozespołów elektrowni wodnych. Wykazano niedostatki i zagrożenia płynące ze stosowania diagnostyki opartej na jednopunktowym pomiarze temperatury. Zaprezentowano wstępna koncepcję nowej metody diagnostycznej opartej na odwrotnym zagadnieniu przepływu ciepła (IPHC).
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Quality negotiation mechanism for e-learning platforms
PublicationZarządzanie jakością w aplikacjach działających w środowiskach sieci WEB opiera się na zadaniach związanych z wykrywaniem jakości połączenia klient - serwer oraz na optymalnym przydziale zasobów wedle jakości takowego połączenia. Optymalne zarządzanie jakością zależy od wypracowanego kompromisu pomiędzy jakością łącza a jakości transportowanego łączem zasobu. Artykuł opisuje możliwy do implementacji mechanizm odpowiedzialny za...
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Comparative study of learning methods for artificial network
PublicationW artykule przedstawiono wyniki badań porównawczych metod uczenia sieci neuronowych takich jak: metoda propagacji wstecznej błędów, rekurencyjna metoda najmniejszych kwadratów, metoda Zangwill'a, metoda algorytmów ewolucyjnych. Celem tych badań jest dobieranie najefektywniejszej metody uczenia do projektowania adaptacyjnego neuronowego regulatora napięcia generatora synchronicznego.metody uczenia, sieć neuronowa, neuronowy regulator...
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Organizational IT Competency, Knowledge Workers and Knowledge Sharing
PublicationIT competency plays a vital role in knowledge management processes. Information technology affects an organization’s ability to store and recall knowledge that has been made explicit through codification, including different forms such as written documents, reports, presentations, patents, formulas, etc. This study aims to measure the influence of a company’s IT competency dimensions such as IT-knowledge,...
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Concrete mix design using machine learning
PublicationDesigning a concrete mix is a process of synthesizing many components, it is not a simple process and requires extensive technical knowledge. The design process itself focuses on obtaining the required strength of concrete. Very often designing a concrete mix takes into account the need to maintain the proper water-demand and frost-resistance features. The parameters that influence the concrete class most significantly are the...
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COLLABORATIVE LEARNING ENVIRONMENT FOR ENGINEERING EDUCATION (COLED)
PublicationCollaborative Learning Environment for Engineering Education is a European project implemented under the Erasmus + program, The main goal of 5 partners from 4 different European countries – Bulgaria, Poland, Portugal and Romania is to develop an innovative collaborative training approach, encompassing curricula related to the introduction of enterprise automation. Project activities are carried out in the period from Dctober 2018...
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Decision making process using deep learning
PublicationEndüstri 4.0, dördüncü endüstri devrimi veya Endüstriyel Nesnelerin İnterneti (IIoT) olarak adlandırılan sanayi akımı, işletmelere, daha verimli, daha büyük bir esneklikle, daha güvenli ve daha çevre dostu bir şekilde üretim yapma imkanı sunmaktadır. Nesnelerin İnterneti ile bağlantılı yeni teknoloji ve hizmetler birçok endüstriyel uygulamada devrim niteliği taşımaktadır. Fabrikalardaki otomasyon, tahminleyici bakım (PdM – Predictive...
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Diagnostics of induction motor bearings - possibility of measurements
PublicationIn induction motors damage in the elements of electromagnetic system, for example in the wiring of stator, rotor or in the magnetic circuit can appear as well as damage of mechanical parts (bearings, rotor, shaft). Bearing diagnostics is so important in supervision of motor condition, because extensive research shows that the bearings arethe elements most susceptible to damage. This paper presents the research which the author...
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A method for evaluating durability of porous slide bearings
PublicationThe article presents the structures of porous bearings bushes and greasy lubricants, and the similarity criterion resulting from this structures. A phisical model is proposed which describes the operation of the porous slide bearing bush taking into account, via analogy, the phenomena taking place in the grease lubricant nodes instead of those observed in the bush structures.Included are the result of experimental tests of three...
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Temperature Measurements in Monitoring of Large Thrust Bearings
PublicationW pracy przedstawiono krytyczną ocenę popularnego systemu diagnostyki dużych łożysk wzdłużnych (np. łożysk nośnych hydrogeneratorów), w którym stosowany jest jednopunktowy pomiar temperatury w klockach łożyskowych. Stwierdzono, że taki układ pomiarowy nie pozwala na bezpieczną eksploatację łożysk, ponieważ posiada bardzo duże opóźnienie czasowe, nie daje informacji o lokalnych zagrożeniach, nie pozwala racjonalnie ustalić poziomów...
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Intelligent video and audio applications for learning enhancement
PublicationThe role of computers in school education is briefly discussed. Multimodal interfaces development history is shortly reviewed. Examples of applications of multimodal interfaces for learners with special educational needs are presented, including interactive electronic whiteboard based on video image analysis, application for controlling computers with facial expression and speech stretching audio interface representing audio modality....
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Temperature measurements in monitoring of large thrust bearings
PublicationW pracy przedstwiono krytyczną analizę aktualnych metod diagnostyki dużych hydrodnamicznych łożysk wzdłużnych hydrozespołów elektrowni wodnych. Wykazano niedostatki i zagrożenia płynące ze stosowania diagnostyki opartej na jednopunktowym pomiarze temperatury. Zaprezentowano wstępna koncepcję nowej metody diagnostycznej opartej na odwrotnym zagadnieniu przepływu ciepła.
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Enterprise Gamification - Learning as a Side Effect of Competition
PublicationGmification in companies can be used for driving desired employees behaviour that are advantageous to their development and performance improvement. This paper presents tools acquired from online social networking services and game mechanisms to encourage managers to compete by providing extended statistics and user profiles features in e-learning system.
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Car-sharing: The Impact on Metropolitan Spatial Structures
PublicationMany examples from the past show that new technologies designed to solve particular problems can also create side effects generating new problems. Some unforeseen or unwanted results may influence space use and spatial structures. Car-sharing is an invention to compete with car ownership. It drastically rise efficiency of car use, reducing the number of vehicles per users. Diffusion of car-sharing is going to accelerate in the...
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Security Information Sharing for the Polish Power System
PublicationThe Polish Power System is becoming increasingly more dependent on Information and Communication Technologies which results in its exposure to cyberattacks, including the evolved and highly sophisticated threats such as Advanced Persistent Threats or Distributed Denial of Service attacks. The most exposed components are SCADA systems in substations and Distributed Control Systems in power plants. When addressing this situation...
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Large Hydrodynamic Thrust Bearings and Their Application in Hydrogenerators
PublicationLarge hydrodynamic thrust bearings are the bearings which, due to hydrodynamic lubrication, allow large axial load to be transferred from a moving part (shaft) to the stationary part via a thin layer of the lubricant (usually oil), thus providing extremely low friction and practically no wear. Hydrogenerators with vertical shafts are the most important application of large thrust bearings. Main design and scientific problems of...
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Blended-learning w nauczaniu przedmiotów nieinformatycznych
PublicationBlended-learning jest coraz powszechniej wykorzystywany w nauczaniu przedmiotów informatycznych lub innych przedmiotów, w których ćwiczenia realizowane są w laboratoriach komputerowych. W przypadku przedmiotów bez dostępu do sal komputerowych, blended-learning wspomaga prowadzenie wykładów i ćwiczeń poprzez np. lekcje interaktywne. Artykuł opisuje zastosowanie form blended-learning w realizacji laboratoriów z przedmiotu Bezpieczeństwo...
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Blended Learning in Teaching Safety of Electrical Installations
PublicationBlended learning becomes more commonly used in teaching information technology or other subjects, which involve practice in computer laboratories. In case of subjects with no access to computer rooms blended learning supports lecturing and teaching classes e.g. interactive lessons. The article presents the use of blended learning forms in Gdansk University of Technology in teaching the subject of Safety of Electrical Installations....
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Affective Learning Manifesto – 10 Years Later
PublicationIn 2004 a group of affective computing researchers proclaimed a manifesto of affective learning that outlined the prospects and white spots of research at that time. Ten years passed by and affective computing developed many methods and tools for tracking human emotional states as well as models for affective systems construction. There are multiple examples of affective methods applications in Intelligent Tutoring Systems (ITS)....
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The Use of Photographs in the Teaching/Learning of Descriptive Geometry
PublicationThe article presents the concept of enriching the Descriptive Geometry course with photographs and several simplified real-life engineering tasks. The photographic images used for the exercises are tightly linked to engineering structures, the given specialization and the surrounding world. The photo image as a record of central projection of a real space can be useful for presentation and analysis of the properties of perspective....
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Evaluation of ChatGPT Applicability to Learning Quantum Physics
PublicationChatGPT is an application that uses a large language model. Its purpose is to generate answers to various questions as well as provide information, help solve problems and participate in conversations on a wide range of topics. This application is also widely used by students for the purposes of learning or cheating (e.g., writing essays or programming codes). Therefore, in this contribution, we evaluate the ability of ChatGPT...
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Strategies for Dealing With Software Product Management Challenges
PublicationSoftware product management, which involves multiple processes and responsibilities and links to many activities within the organisation, increases the success rate of IT projects. However, the adoption of product management activities and the implementation of the software product manager role itself varies between companies. This research explores the topic of software product managers’ strategies for dealing with challenges...
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Sustainable Knowledge Sharing Model for IT Agile Projects
PublicationIn order to overcome work environment challenges and remain competitive in the market, organisations must adapt. An organisation's competitiveness can be improved through knowledge sharing; however, improvement without responsibility can have a negative impact on the sociotechnical environment which people cannot fully comprehend. According to researchers, business involvement in sustainable development goals remains minimal [51]....
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Research on Linear Actuators for Active Foil Bearings
PublicationActive foil bearings are a kind of gas foil bearing. They contain actuators which allow for modification of the bearing sleeve size and the shape of the lubrication gap. Rotor vibrations can be actively controlled by these changes. It is possible, among other things, to reduce the starting torque, control the vibration amplitude at different speeds and improve operational safety. Prototypes of active foil bearings are being developed...
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Introduction to the special issue on machine learning in acoustics
PublicationWhen we started our Call for Papers for a Special Issue on “Machine Learning in Acoustics” in the Journal of the Acoustical Society of America, our ambition was to invite papers in which machine learning was applied to all acoustics areas. They were listed, but not limited to, as follows: • Music and synthesis analysis • Music sentiment analysis • Music perception • Intelligent music recognition • Musical source separation • Singing...
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Deep learning for recommending subscription-limited documents
PublicationDocuments recommendation for a commercial, subscription-based online platform is important due to the difficulty in navigation through a large volume and diversity of content available to clients. However, this is also a challenging task due to the number of new documents added every day and decreasing relevance of older contents. To solve this problem, we propose deep neural network architecture that combines autoencoder with...
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Towards Knowledge Sharing Oriented Adaptive Control
PublicationIn this paper, we propose a knowledge sharing oriented approach to enable a robot to reuse other robots' knowledge by adapting itself to the inverse dynamics model of the knowledge-sharing robot. The purpose of this work is to remove the heavy fine-tuning procedure required before using a new robot for a task via reusing other robots' knowledge. We use the Neural Knowledge DNA (NK-DNA) to help robots gain empirical knowledge and...
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Machine Learning and Electronic Noses for Medical Diagnostics
PublicationThe need for noninvasive, easy-to-use, and inexpensive methods for point-of-care diagnostics of a variety of ailments motivates researchers to develop methods for analyzing complex biological samples, in particular human breath, that could aid in screening and early diagnosis. There are hopes that electronic noses, that is, devices based on arrays of semiselective or nonselective chemical sensors, can fill this niche. Electronic...
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Machine Learning Techniques in Concrete Mix Design
PublicationConcrete mix design is a complex and multistage process in which we try to find the best composition of ingredients to create good performing concrete. In contemporary literature, as well as in state-of-the-art corporate practice, there are some methods of concrete mix design, from which the most popular are methods derived from The Three Equation Method. One of the most important features of concrete is compressive strength, which...
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Learning design of a blended course in technical writing
PublicationBlending face-to-face classes with e-learning components can lead to a very successful outcome if the blend of approaches, methods, content, space, time, media and activities is carefully structured and approached from both the student’s and the tutor’s perspective. In order to blend synchronous and asynchronous e-learning activities with traditional ones, educators should make them inter-dependent and develop them according to...
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Impact of technology on learning paradigms and teaching practices
PublicationArtykuł stara się omówić różne kwestie dotyczące wpływu technologii na proces nauczania poprzez zaprezentowanie określonych przykładów. Jest próbą sformułowania ogólnych wniosków oraz zweryfikowania kontrowersyjnych opinii.
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Accurate Modeling of a Lossy Ferrite Circular Guide Section Magnetized Through a Rotary Four-Pole Magnetic Field
PublicationKorzystając z metody rodzajów sprzężonych opracowano model matematyczny umożliwiający określenie parametrów falowych i rozkładów pola em. fal występujących w ferrytowym falowodzie cylindrycznym magnesowanym czterobiegunowym polem magnetycznym. W oparciu o model określono macierz rozproszenia sekcji falowodu. Opracowane oprogramowanie pozwoliło na zbadanie charakterystyk częstotliwościowych sekcji ferrytowej i wskazanie możliwości...
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Analysis of impact of lossy audio compression on the robustness of watermark embedded in the DWT domain for non-blind copyright protection
PublicationA methodology of non-blind watermarking of the audio content is proposed. The outline of audio copyright problem and motivation for practical applications are discussed. The algorithmic theory pertaining watermarking techniques is briefly introduced. The system architecture together with employed workflows for embedding and extracting the watermarks are described. The implemented approach is described and obtained results are reported....
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Optical monitoring of electrochemical processes with ITO-based lossy-mode resonance optical fiber sensor applied as an electrode
PublicationIn this work we discuss the application of optical fiber sensors based on lossy-mode resonance (LMR) phenomenon for real-time optical monitoring of electrochemical processes. The sensors were obtained by a reactive high power impulse magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. The LMR effect made monitoring of changes in optical properties of both ITO and its surrounding medium...