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Search results for: hearing loss
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Electron energy-loss spectroscopy of excited states of the diazine molecules: Pyridazine
PublicationExcitation of the valence electronic states of the pyridazine molecules in the gas phase have been studied using the technique of electron energy-loss spectroscopy. Varying the electron scattering conditions, the residual electron energy and scattering angle, enabled the optically-allowed and -forbidden excitations to be differentiated. The measured energy-loss spectra enabled the vertical excitation energies of the observed states...
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Path Loss Measurements in Wideband Radio Link Designed for Maritime Environment
PublicationIn the article, the research and analysis of path loss in designed and evaluated digital radio link for high-speed data transmission in maritime environment is presented. Collected samples of received signal were used to determine the mean path loss and its standard deviation. Measuring campaign was carried out in a real maritime conditions. The mean value of path loss reached 126 dB on a distance of 11.16 km.
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Determination of Mechanical Energy Loss in Steady Flow by Means of Dissipation Power
PublicationWhen systems of simple geometry like pipes or regular channels are considered, the mechan- ical energy loss of the fluid flow can be expressed by local and longitudinal empirical energy loss coefficients. However, in the case of large spatially distributed objects, there are no simple approaches to this task. In practice, general recommendations addressing different types of objects are used, but they usually provide very coarse...
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An Approach to Mean Path Loss Model Estimation for Off-Body Channels
PublicationThis paper presents an approach to estimation of the mean path loss model parameters in off-body Body Area Networks channels. In this approach, the path loss exponent is constrained to a value obtained for the line-of-sight (LoS) propagation in the co-polarised channel, considering a generalised static scenario. The comparison of the goodness of fit between the proposed approach and other approaches, for a set of measurements obtained...
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It applications for the remote testing of hearing.
PublicationTelemedycyna odgrywa coraz wiekszą rolę w diagnostyce i leczeniu osób z ubytkami słuchu. Jest to związane m.in. ze specyfiką badań audiometrycznych. Postęp technologiczny w dziedzinie aparatów słuchowych i implantów ślimakowych wymusza nowe metody diagnozy w audiologii, jak również w praktyce otolaryngologicznej. Serwis ''Telezdrowie'', w którym zaimplementowano liczne testy przesiewowe jest przykładem prowadzenia diagnostyki w...
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Multimedia Applications for the Hearing Impaired.
PublicationJednym z elementów przeciwdziałania szybko narastającym zagrożeniom niedosłuchem są aplikacje oprate na nowoczesnych technologiach. W wyniku współpracy Katedry Systemów Multimedialnych PG z warszawskim Instytutem Fizjologii i Patologii Słuchu opracowano wdrożone na szeroką skale multimedialne systemy przesiewowych badań zmysłów komunikowania się. Ponadto, nowsze opracowania dotyczą maskowania szumów usznych z wykorzystaniem linearyzacji...
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Predicting Thrust Loss of Ship Propellers Due to Ventilation and Out-of-Water Effect
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Forest habitat loss and fragmentation in Central Poland during the last 100 years
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Odontogenic orbital cellulitis in a young man with complete vision loss – a case report
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Modification of Selected Propagation Models in Terms of Path Loss Estimation in Container Terminal
PublicationIt is particularly important to look for any propagation model that could be useful for designing mobile radio networks in container terminal environment. Selected propagation models have been investigated. Firstly - basing on measurements results - they have been evaluated in this scope and the analysis has shown, that the adjustment is needed. This modification improved significantly the accuracy of path loss modelling. For the...
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Simplified Approach for Broadband RF Testing of Low Loss Magneto-Dielectric Samples
PublicationIn this paper, an attractive measurement techniqueis proposed to retrieve the broadband permittivity and permeabil-ity of the magneto-dielectric materials. The proposed techniqueis quite novel which mitigates the major problems associatedwith the conventional broadband RF material characterizationtechniques such as numerical instability and phase uncertaintywhen the length of the sample exceeds...
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Multiscalar Control Based Airgap Flux Optimization of Induction Motor for Loss Minimization
PublicationBased on the induction motor model, considering the core loss resistance that accounts for magnetic characteristic saturation, a speed control approach is devised with an adaptive full-order (AFO) speed observer. The induction motor model analysis is done sincerely in a stationary reference frame. The control approach incorporates a flux reference generator designed to meet optimal operational circumstances and a nonlinear speed...
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Assessment of User Mobility’s Influence on System Loss in Several Body-to-Body Scenarios
PublicationIn this paper, Body-to-Body communications in indoor and outdoor environments for different on-body antenna configurations and different mobility scenarios were studied, based on system loss measurements at 2.45 GHz. The main objective is to properly characterise the influence of the Transmitter-Receiver configuration on system loss and fast fading behaviour, the latter being modelled by the Rice Distribution. Globally, it is observed...
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Inlet air fogging of marine gas turbine in power output loss compensation
PublicationThe use of inlet air fogging installation to boost the power for gas turbine engines is widely applied in the power generation sector. The application of fogging to mechanical drive is rarely considered in the literature [1]. This paper will cover some considerations relating to its application to gas turbines in ship drive. There is an important evaporative cooling potential throughout the world when the dynamic data is evaluated,...
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Proposal of a System Loss Model for Body Area Network in Passenger Ferry Environment
PublicationIn the paper, proposal of an empirical off-body system loss model for Body Area Networks working in a passenger ferry environment at 2.45 GHz has been presented. The measurements were carried out for dynamic scenarios in the discotheque passenger ferry environment. The general model formula consists of three components: mean system loss, attenuation resulting from the variable antenna position on the human body, and attenuation...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublicationThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublicationThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Remote learning among students with and without reading difficulties during the initial stages of the COVID-19 pandemic
PublicationThis article presents the results of a survey on yet under-researched aspects of remote learning and learning difficulties in higher education during the initial stage (March – June 2020) of the COVID-19 pandemic. A total of 2182 students from University of Warsaw in Poland completed a two-part questionnaire regarding academic achievements in the academic year 2019/2020, living conditions and stress related to learning and pandemic,...
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Contactless hearing aid designed for infants
PublicationIt is a well known fact that language development through home intervention for a hearing-impaired infant should start in the early months of a newborn baby's life. The aim of this paper is to present a concept of a contactless digital hearing aid designed especially for infants. In contrast to all typical wearable hearing aid solutions (ITC, ITE, BTE), the proposed device is mounted in the infant's bed with any parts of its set-up...
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Special hearing aid for stuttering people
PublicationDzięku postępowi w dziedzienie cyfrowego przetwarzania sygnałów możliwe stało zbudowanie subminiaturowego urządzenia łączącego funkcje aparatu słuchowego i korektora mowy. Takie urządzenie, mimo niewielkich rozmiarów, jest w stanie wykonywać skomplikowane alggorytmy a jego oprogramowanie może być łatwo zmieniane. W pracy skupiono się na zagadnieniach związanych z opracowniem prototypu i implementacją algorytmów korekcji słuchu...
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Hearing and stomatognathic system: Searching for a link
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Evaluating the Hearing of Patients with Pseudoexfoliation Syndrome
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Vaccine versus infection – COVID-19-related loss of training time in elite athletes
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The influence of the thickness, recombination and space charge on the loss of photocurrent in organic semiconductors: an analytical model
PublicationWe propose an analytical model of the photocurrent efficiency dependence on the light intensity in organic semiconductors. The influence of the thickness of sample, space charge effects and recombination of charge on the loss of photocurrent has been considered. We demonstrate that the presented model is the enhancement of an analytical model reported recently by Rappaport et al (2005 J. Appl. Phys. 98 033714). The method to identify...
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublicationIn this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...
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Low-Loss Mechanically Tunable Resonator and Phase Shifters in Groove Gap Waveguide Technology
PublicationThis research is focused on the design and realization of high-performance high-power variable phase shifters in groove gap waveguide technology. Specifically, it is shown that the unique characteristic of groove gap waveguides, which is its proper operation without the need for electrical connection between the top and bottom sections of the waveguide, can be used to design mechanically tunable devices. Using the proposed method,...
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Performance Evaluation of GAM in Off-Body Path Loss Modelling for Body Area Networks
PublicationThis paper addresses the performance evaluation of an off-body path loss model, based on measurements at 2.45 GHz, which has been developed with the use of the Generalised Additive Model, allowing to model a non-linear dependence on different predictor variables. The model formulates path loss as a function of distance, antennas’ heights, antenna orientation angle and polarisation, results showing that performance is very sensitive...
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Energy Loss Coefficients ki in a Displacement Pump and Hydraulic Motor used in Hydrostatic Drives
PublicationThe article aims at defining and analysing the energy loss coefficients in design solutions of rotating displacement machines, with a piston machine as an example. The energy losses observed in these machines include mechanical loss, volumetric loss, and pressure loss. The scale and relations between these losses in different machines depend on machine design and manufacturing quality, and on operating parameters. The operating...
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Propagation Loss and Interference Analysis for 5G Systems in the Context of C-ITS System Implementation
PublicationThe article presents the concept of implementing subsequent phases of services for the C-ITS system (the Cooperative Intelligent Transport Systems), based on the European Parliament resolution of March 2018. Next, the 5G systems, in the context of their possible cooperation with C-ITS systems, were discussed. Numerical propagation analysis was performed for V2V and V2I type communication based on two different propagation models....
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Przepowiednia emigracyjnego losu Aleksandra Sołżenicyna
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Synthesis of coupled lossy resonator filters.
PublicationA technique for fast synthesis of coupling matrix low-pass prototypes of generalized. Chebyshev bandpass filters with lossy resonators is presented in this letter. The coupling matrix is found by solving a nonlinear least squares problem based on zeros and poles of filter's transfer functions.
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The lows of thermodynamics: cell energy transfer
PublicationW pracy przedstawiono zasady termodynamiki i wymiany ciepła w organizmach żywych i urządzeniach technicznych. Przedstawiono zasady stosowania praw fizycznych związanych z konwersją energii w organizmach żywych.
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ATTEMPTS OF THERMAL IMAGING CAMERA USAGE IN ESTIMATIONS OF THE CONVECTIVE HEAT LOSS FROM A VERTICAL PLATE
PublicationIn this paper a new method for determining heat transfer coefficients using a gradient method has been developed. To verify accuracy of the proposed method vertical isothermal heating plate with natural convection mechanism has been examined. This configuration was deliberately chosen, because of the fact that such case is historically the earliest and most thoroughly studied and its rich scientific documentation - the most reliable....
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Low-Loss 3D-Printed Waveguide Filters Based on Deformed Dual-Mode Cavity Resonators
PublicationThis paper introduces a new type of waveguide filter with smooth profile, based on specially designed dual-mode (DM) cavity resonators. The DM cavity design is achieved by applying a shape deformation scheme. The coupling between the two orthogonal cavity modes is implemented by breaking the symmetry of the structure, thus eliminating the need for additional coupling elements. The modes operating in the cavity are carefully analyzed...
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Broad Stopband, Low-Loss, and Ultra-Compact Dual-Mode Bandpass Filter Based on HMSIRC
PublicationIn this investigation, an ultra-compact dual-mode bandpass filter (BPF) with a wide stopband re-sponse is realized by using a half-mode substrate-integrated rectangular cavity (HMSIRC). The HMSIRC resonator is designed with a cavity that is rectangular in shape and has metallic vias along three of the sides. The fourth side is open-ended and contains microstrip feed lines. For the purpose of constructing a magnetic wall, a rectangular...
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Modulation of dielectric properties in low-loss polypropylene-based composites at GHz frequencies: theory and experiment
PublicationPolymer composites with high dielectric constant and low loss tangent are highly regarded as substrates for modern high-speed electronics. In this work, we analyze the high-frequency dielectric properties of two types of composites based on polypropylene infused with high-dielectric-constant microparticles. Two types of fillers are used: commercial ceramics or titanium oxide ( TiO2) with different concentrations. The key observation...
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Digital hearing aid with time and spectral transposition.
PublicationNastępstwem uruchomienia w Polsce, prowadzonych na szeroką skalę, badań przesiewowych słuchu jest konieczność zaoferowania pomocy osobom cierpiącym na niedosłuch poprzez leczenie i protetykę słuchu. Tymczasem, aktualnie oferowane rozwiązania aparatów słuchowych nie są w stanie sprostać niektórym specjalistycznym potrzebom aparatowania, m. in.: najmłodszych dzieci, osób pracujących w hałasie, pilotów wojskowych oraz osób korzystających...
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Modeling of acoustics of hearing aid earmold systems
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Waveguide modeling as a tool for fitting a hearing aid
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Waveguide model of the hearing aid earmold system
PublicationBackground The earmold system of the Behind-The-Ear hearing aid is an acoustic system that modifies the spectrum of the propagated sound waves. Improper selection of the earmold system may result in deterioration of sound quality and speech intelligibility. Computer modeling methods may be useful in the process of hearing aid fitting, allowing physician to examine various earmold system configurations and choose the optimum one...
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Waveguide model of the hearing aid earmold system
PublicationBackground The earmold system of the Behind-The-Ear hearing aid is an acoustic system that modifies the spectrum of the propagated sound waves. Improper selection of the earmold system may result in deterioration of sound quality and speech intelligibility. Computer modeling methods may be useful in the process of hearing aid fitting, allowing physician to examine various earmold system configurations and choose the optimum one...
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Hearing aid operating in acoustical free field
PublicationAparatowanie bardzo małych dzieci (od 5 miesiąca życia) za pomocą standardowych protez słuchu natrafia na wiele trudności natury praktycznej. Dotyczy to procesu dopasowania aparatu słuchowego, czyli doboru jego ustawień stosownie do aktualnych charakterystyk ubytku słuchu dzieci. Tymczasem wczesne aparatowanie jest zagadnieniem o ogromnym zanczeniu dla rozwoju słuchu, mowy i ogólnej inteligencji dziecka. Referat prezentuje uzyskane...
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Speech recognition system for hearing impaired people.
PublicationPraca przedstawia wyniki badań z zakresu rozpoznawania mowy. Tworzony system wykorzystujący dane wizualne i akustyczne będzie ułatwiał trening poprawnego mówienia dla osób po operacji transplantacji ślimaka i innych osób wykazujących poważne uszkodzenia słuchu. Active Shape models zostały wykorzystane do wyznaczania parametrów wizualnych na podstawie analizy kształtu i ruchu ust w nagraniach wideo. Parametry akustyczne bazują na...
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Expert media approach to hearing aids fitting
PublicationW artykule zaprezentowano problematykę dopasowania protez słuchu. Przedstawiono system ekspercki, który pozwala na znalezienie charakterystyk aparatu słuchowego adekwatnego do uszkodzenia słuchu. System został oparty o metodę zbiorów przybliżonych i logikę rozmytą.
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Internet-based automatic hearing assessment system
PublicationCelem referatu jest prezentacja systemu przesiewowego badania słuchu w oparciu o Internet. Wady słuchu stanowią jedną z najszybciej postępujących chorób we współczesnym społeczeństwie. W tym kontekście ważne staje się umożliwienie przeprowadzania masowych testów wykrywających ubytki słuchu. Przedstawiona aplikacja zawiera audiometryczny test tonalny, test ilustrowany dla dzieci oraz test rozumienia mowy w szumie. Po zakończeniu...
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Loudness Scaling Tests in Hearing Problems Detection
PublicationThe number of people using portable audio players has increased significantly over the recent years. This implies the rise in the number of people having hearing loss problems. Therefore, there is a need to find appropriate procedures that simplify the process of the hearing problem detection. Investigations performed show that audiometric tests may not be sufficient to assess hearing in young people. Contrarily, the obtained results...
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Knowledge sharing and knowledge hiding in light of the mistakes acceptance component of learning culture- knowledge culture and human capital implications
PublicationPurpose: This study examines the micromechanisms of how knowledge culture fosters human capital development. Method: An empirical model was developed using the structural equation modeling method (SEM) based on a sample of 321 Polish knowledge workers employed in different industries. Findings: This study provides direct empirical evidence that tacit knowledge sharing supports human capital, whereas tacit knowledge hiding does...
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Study of Bioreductive Anticancer Agent RH-1-Induced Signals Leading the Wild-Type p53-Bearing Lung Cancer A549 Cells to Apoptosis
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Magnetoacoustic Heating in Nonisentropic Plasma Caused by Different Kinds of Heating-Cooling Function
PublicationThe nonlinear phenomena which associate with magnetoacoustic waves in a plasma are analytically studied. A plasma is an open system with external inflow of energy and radiation losses. A plasma’s flow may be isentropically stable or unstable. The nonlinear phenomena occur differently in dependence on stability or instability of a plasma’s flow. The nonlinear instantaneous equation which describes dynamics of nonwave entropy mode...
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Comparison of percentage excess weight loss after laparoscopic sleeve gastrectomy and laparoscopic adjustable gastric banding
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