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Search results for: ACOUSTICS OFELECTROLYTES
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Comparison of various speech time-scale modificartion methods
PublicationThe objective of this work is to investigate the influence of the different time-scale modification (TSM) methods on the quality of the speech stretched up using the designed non-uniform real-time speech time-scale modification algorithm (NU-RTSM). The algorithm provides a combination of the typical TSM algorithm with the vowels, consonants, stutter, transients and silence detectors. Based on the information about the content and...
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Sacral sound-engineering
PublicationOrganologic and campanologic acoustical problems due to applications to sacral objects are characterized on ground of numerous reviewed publications and engineering reports. Participations of several involved research centres, mostly Polish, at solving these problems are evaluated. Some desirable future developments are indicated. Appendices bring examples of documentation on selected investigated objects.
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Developing assumptions for the tram noise attenuation passive system using the noise maps analysis method
PublicationThe paper presents experimental research carried out to determine the possible actions to reduce thenoise generated by trams in a highly urbanised area. A few design strategies affecting tram ride qualityhave been presented – especially in the aspect of the acoustic phenomena. Main sources of the noisein trams were characterised. The paper includes selected results of comprehensive...
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Investigation of noise threats and their impact on hearing in selected schools - a pilot study.
PublicationNoise measurements conducted in selected schools in Gdansk area are presented in this paper. The main aim of this research was to determine noise threats at schools. Some objective measurements of the acoustic climate were performed employing a noise monitoring station engineered at the Multimedia System Department, Gdansk University of Technology. Simultaneously, subjective noise annoyance examinations were carried out among pupils...
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Sound velocity and parameter of nonlinearity of a ternary mixture consisting of water, vapour and dry air
PublicationRozpatruje się własności akustyczne mieszanki trójskładnikowej zawierającej wodę, parę wodną i suche powietrze. Dokładne obliczenia pozwoliły na wyprowadzenie prędkości dźwięku i parametru nieliniowości jako funkcji koncentracji pary wodnej i powietrza przy zadanych warunkach równowagowych. Rozpatrywane są dwa typy mieszanin. Przedstawiono wzory ogólne oraz symulacje numeryczne.
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Classification of Music Genres Based on Music Separation into Harmonic and Drum Components . Klasyfikacja gatunków muzycznych wykorzystująca separację instrumentów muzycznych
PublicationThis article presents a study on music genre classification based on music separation into harmonic and drum components. For this purpose, audio signal separation is executed to extend the overall vector of parameters by new descriptors extracted from harmonic and/or drum music content. The study is performed using the ISMIS database of music files represented by vectors of parameters containing music features. The Support Vector...
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Impact of Microphytobenthos Photosynthesis on the Characteristics of the Echo Signal from Baltic Sandy Sediments
PublicationThe understanding the influence of biological processes on the characteristics of the signals backscattered by the sea floor is crucial in the development of the hydroacoustical benthic habitat classification techniques. The impact of the microphytobenthos photosynthesis on the acoustical backscattering properties of the Atlantic sandy sediments was previously demonstrated by Holliday et al. (2004) and Wildman and Huettel (2012). To...
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Study of Noise Propagation for Small Vessels
PublicationThe paper presents the results of the noise propagation analysis in ship structures tested in a number of AHTS (Anchor Handling Tug Supply) vessels. Statistical Energy Analysis (SEA) based on numerical model developed specially for the purpose of this numerical investigation were conducted. This numerical model enabled the analysis of both the structural elements and the acoustic spaces. For the detailed studies 47 points fixed...
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In Memoriam Professor Jerzy KAPELEWSKI
PublicationProfessor Jerzy Kapelewski In Memoriam
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Nonlinear Interaction of Magnetoacoustic Modes in a Quasi-Isentropic Plasma Flow
PublicationThe nonlinear interaction of magnetoacoustic waves in a plasma is analytically studied. A plasma is an open system. It is affected by the straight constant equilibrium magnetic flux density forming constant angle with the wave vector which varies from 0 till . The nonlinear instantaneous equation which describes excitation of secondary wave modes in the field of intense magnetoacoustic perturbations is derived by use of projecting....
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Magnetosonic Excitation of the Entropy Perturbations in a Plasma with Thermal Conduction Depending on Temperature
PublicationNonlinear excitation of the entropy perturbations by magnetosonic waves in a uniform and infinite plasma model is considered. The wave vector of slow or fast mode forms an arbitrary angle (0 B B ) with the equilibrium straight magnetic field, and all perturbations are functions of the time and longitudinal coordinate. Thermal conduction is the only factor which destroys isentropicity of wave perturbations and causes the nonlinear...
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Numerical Model of Surface and Quasi-Spherical Sea Noise and Its Application to Analysis of DIFAR Systems
PublicationVarious types of passive sonar systems are used to detect submarines. These activities are complex and demanding. Therefore, computer simulations are most often used at the design stage of these systems. For this reason, it is also necessary to simulate the acoustic ambient noise of the sea. The article proposes a new numerical model of surface and quasi-spherical sea noise and presents its statistical parameters. The results of...
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Performance of Noise Map Service Working in Cloud Computing Environment
PublicationIn the paper a noise map service designated for the user interested in environmental noise subject is presented. It is based on cloud computing. Noise prediction algorithm and source model, developed for creating acoustic maps, are working in cloud computing environment. In the study issues related to noise modeling of sound propagation in urban spaces are discussed with a special focus on road noise. Examples of results obtained...
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Impact of Spatial Noise Correlation on Bearing Accuracy in DIFAR Systems
PublicationDIFAR type underwater passive systems are one of the more commonly used tools for detecting submarines. At the design stage, which usually uses computer simulations, it is necessary to generate acoustic noise of the sea. It has been shown that correlating noise significantly reduces these errors compared to the assumption that noise is uncorrelated. In addition, bearing errors have been shown to be the same in systems with a commonly...
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A study on of music features derived from audio recordings examples – a quantitative analysis
PublicationThe paper presents a comparative study of music features derived from audio recordings, i.e. the same music pieces but representing different music genres, excerpts performed by different musicians, and songs performed by a musician, whose style evolved over time. Firstly, the origin and the background of the division of music genres were shortly presented. Then, several objective parameters of an audio signal were recalled that...
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Mutual Clutter Suppression Techniques for FM Sonars
PublicationThe article presents methods that help in the elimination of mutual clutter as well as the consequences of two FM sounding signal sonars operating in the same body of water and frequency band. An in-depth analysis of mutual clutter was carried out. The effects of sounding signal differentiation were determined, as was the Doppler effect on mutual clutter suppression. One of the methods analysed is of particular interest in a situation...
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Standing Waves in a Rectangular Resonator Containing Acoustically Active Gases
PublicationThe distribution of perturbations of pressure and velocity in a rectangular resonator is considered. A resonator contains a gas where thermodynamic processes take place, such as exothermic chemical reaction or excitation of vibrational degrees of a molecule’s freedom. These processes make the gas acoustically active under some conditions. We conclude that the incident and reflected compounds of a sound beam do not interact in the...
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Loudness Scaling Test Based on Categorical Perception
PublicationThe main goal of this research study is focused on creating a method for loudness scaling based on categorical perception. Its main features, such as: way of testing, calibration procedure for securing reliable results, employing natural test stimuli, etc., are described in the paper and assessed against a procedure that uses 1/2-octave bands of noise (LGOB) for the loudness growth estimation. The Mann-Whitney U-test is employed...
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On the Nonlinea Distortions of Sound and its Coupling with Other Modes in a Gasesous Plasma with Finite Electric Conductivity in a Magnetic Field
PublicationNonlinear phenomena of the planar and quasi-planar magnetoacoustic waves are considered. We focus on deriving of equations which govern nonlinear excitation of the non-wave motions by the intense sound in initially static gaseous plasma. The plasma is treated as an ideal gas with finite electrical conductivity permeated by a magnetic field orthogonal to the trajectories of gas particles. This introduces dispersion of a flow. Magnetoacoustic...
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Standing Waves in One-Dimensional Resonator Contaning an Ideal Isothermal Gas Affected by the Constant Mass Force
PublicationThe study is devoted to standing acoustic waves in one-dimensional planar resonator which containing an ideal gas. A gas is affected by the constant mass force. Two types of physically justified boundary conditions are considered: zero velocity or zero excess pressure at both boundaries. The variety of nodal and antinodal points is determined. The conclusion is that the nodes of pressure and antinodes of velocity do not longer...
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DAB vs DAB+ Radio Broadcasting: a Subjective Comparative Study
PublicationIn the age of digital media, delivering high quality content to consumers is one of the most demanding tasks. There exist numerous broadcasting standards, with different pros and cons, and the DAB/DAB (Digital Audio Broadcasting) system is one of the most popular among them. From an engineer’s perspective, efficient resource management under limited bandwidth conditions has always been a challenge. In this paper a subjective quality...
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Voiceless Stop Consonant Modelling and Synthesis Framework Based on MISO Dynamic System
PublicationA voiceless stop consonant phoneme modelling and synthesis framework based on a phoneme modelling in low-frequency range and high-frequency range separately is proposed. The phoneme signal is decomposed into the sums of simpler basic components and described as the output of a linear multiple-input and single-output (MISO) system. The impulse response of each channel is a third order quasi-polynomial. Using this framework, the...
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Sound engineering as our commitment to its creators in Poland
PublicationSound engineering is an interdisciplinary and rapidly expanding domain. It covers many aspects, such as sound perception, studio and sound mastering technology, music information retrieval including content-based search systems and automatic music transcription frameworks, sound synthesis, sound restoration, electroacoustics, and other ones constituting multimedia technology. Moreover, machine learning methods applied to the topics...
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Assessment of the Effectiveness of a Short-term Hearing Aid Use in Patients with Different Degrees of Hearing Loss
PublicationThe study presents evaluating the effectiveness of the hearing aid fitting process in the short-term use (7 days). The evaluation method consists of a survey based on the APHAB (Abbreviated Profile of Hearing Aid Benefit) questionnaire. Additional criteria such as a degree of hearing loss, number of hours and days of hearing aid use as well as the user’s experience were also taken into consideration. The outcomes of the benefit...
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In Memoriam Professors Marianna Sankiewicz-Budzyński and Gustaw K.E. Budzyński - Founders of the Polish Audio Engineering
PublicationBiography and scientific achievements of Professors Marianna Sankiewicz-Budzyński and Gustaw K.E. Budzyński - Founders of the Polish Audio Engineering.
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Modelling and Measurement of Folk Guitar: Truss Rod and Strings in Numerical Analysis of Tone
PublicationThe study makes an attempt to model a complete vibrating guitar including its non-linear features, specifically the tension-compression of truss rod and tension of strings. The purpose of such a model is to examine the influence of design parameters on tone. Most experimental studies are flawed by uncertainties introduced by materials and assembly of an instrument. Since numerical modelling of instruments allows for deterministic...
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Nonlinear Interaction of Modes in a Planar Flow of a Gas with Viscous and Thermal Attenuation
PublicationThe nonlinear interaction of wave and non-wave modes in a gas planar flow are considered. Attention is mainly paid to the case when one sound mode is dominant and excites the counter-propagating sound mode and the entropy mode. The modes are determined by links between perturbations of pressure, density, and fluid velocity. This definition follows from the linear conservation equations in the differential form and thermodynamic...
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On the Consumption of Multimedia Content Using Mobile Devices: a Year to Year User Case Study
PublicationIn the early days, consumption of multimedia content related with audio signals was only possible in a stationary manner. The music player was located at home, with a necessary physical drive. An alternative way for an individual was to attend a live performance at a concert hall or host a private concert at home. To sum up, audio-visual effects were only reserved for a narrow group of recipients. Today, thanks to portable players,...
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Non-Linear Interaction of Harmonic Waves in a Quasi-Isentropic Flow of Magnetic Gas
PublicationThe diversity of wave modes in the magnetic gas gives rise to a wide variety of nonlinear phenomenaassociated with these modes. We focus on the planar fast and slow magnetosound waves in the geometryof a flow where the wave vector forms an arbitrary angleθwith the equilibrium straight magnetic field.Nonlinear distortions of a modulated signal in the magnetic gas are considered and compared to thatin unmagnetised gas. The case of...
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Magnetoacoustic Heating of Plasma Caused by Periodic MagnetosoundPerturbations with Discontinuities in a Quasi-Isentropic Magnetic Gas
PublicationThe magnetoacoustic heating of plasma by harmonic or periodic saw-tooth perturbations at a trans-ducer is theoretically studied. The planar fast and slow magnetosound waves are considered. The wavevector may form an arbitrary angleθwith the equilibrium straight magnetic field. In view of variableθand plasma-β, the description of magnetosound perturbations and appropriate magnetosound heatingis fairly difficult. The scenario of...
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Subjective and Objective Comparative Study of DAB+ Broadcast System
PublicationBroadcasting services seek to optimize their use of bandwidth in order to maximize user’s quality of experience. They aim to transmit high-quality digital speech and music signals at the lowest bitrate. They intend to offer the best quality under available conditions. Due to bandwidth limitations, audio quality is in conflict with the number of transmitted radio programs. This paper analyzes whether the quality of real-time digital...
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Nonlinear Excitation of the Non-Wave Perturbations by the Magnetoacoustic Waves in the Non-Isentropic Plasma
PublicationNonlinear excitation of slow modes by the planar magnetosonic perturbations in a plasma is discussed. Plasma is an open system due to radiation and external heating. This may stipulate enhancement of wave perturbations and hence the acoustical activity of plasma. Plasma is assumed to be a homogeneous ideal gas with infinite electrical conductivity. The straight magnetic field is orthogonal to the velocity of fluid’s...
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Theoretical studies of nonlinear generation efficiency in a bubble layer
PublicationCelem pracy jest teoretyczna analiza propagacji fal o dużym natężeniu w warstwie z pęcherzykami. Przedstawiono model matematyczny zjawiska w tym omówiono problem wyznaczania prędkości fazowej, współczynnika tłumienia i częstotliwości rezonansowej pęcherzyków. Badano zmiany amplitud pierwszej i drugiej harmonicznej ciśnienia fali odbitej i bieżącej w funkcji grubości warstwy oraz względnej koncentracji pęcherzyków. Rozważano pęcherzyki...
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Objectivization of Audio-Visual Correlation analysis
PublicationSimultaneous perception of audio and visual stimuli often causes the concealment or misrepresentation of information actually contained in these stimuli. Such effects are called the ''image proximity effect'' or the ''ventriloquism effect'' in literature. Until recently, most research carried out to understand their nature was based on subjective assessments. The Authors of this paper propose a methodology based on both subjective...
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Tinnitus Therapy Based on High-Frequency Linearization Principles - Preliminary Results
PublicationThe aim of this work is to present problems related to tinnitus symptoms, its pathogenesis, hypotheses on tinnitus causes, and therapy treatment to reduce or mask the phantom noise. In addition, the hypothesis on the existence of parasitic quantization that accompanies hearing loss has been recalled. Moreover, the paper describes a study carried out by the Authors with the application of high-frequency dither having specially formed...
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Dependence of harmonic generation on primary wave pressure distribution
PublicationPraca dotyczy numerycznego badania zagadnienia wytwarzania harmonicznych ciśnienia podczas rozchodzenia się fal o skończonej amplitudzie, promieniowanych przez źródła kołowe o różnych rozkładach. Model matematyczny zbudowano w oparciu o równanie KZK. Do numerycznego rozwiązania problemu zastosowano metodę bilansu harmonicznych i metodę różnic skończonych. Analizowano zmiany składowych harmonicznych ciśnienia w obrębie wiązki akustycznej....
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Sound velocity and parameter of nonlinearity in the two-component relaxing mixtures
PublicationRozpatruje się własności akustyczne mieszanki dwuskładnikowej zawierającej gaz doskonały i parę cieczy bądź pył ciała stałego. Dokładne obliczenia pozwoliły na wyprowadzenie prędkości dźwięku i parametru nieliniowości jako funkcji koncentracji jednej ze składowych mieszaniny przy zadanych warunkach równowagowych. Przedstawiono wzory ogólne oraz symulacje numeryczne.
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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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MTS pilot tone tracking for "wow" distortion determination
PublicationArtykuł przedstawia nowy algorytm do wyznaczania charakterystyki kołysania dźwięku na podstawie śledzenia zmian tonu pilota MTS. Śledzenie zmian częstotliwości nośnej tonu MTS pozwala określić zmienną w czasie głębokość pasożytniczych modulacji częstotliwości będących konsekwencją kołysania. Na tej podstawie tworzona jest charakterystyka zniekształcenia. Proponowany algorytm bazuje na zaproponowanej wcześniej metodzie śledzenie...
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Modulation frequency constraints on wow and flutter determination
PublicationOpracowane wcześniej algorytmy do określania charakterystyki kołysania i drżenia dźwięku okazały się pomocne w rekonstrukcji rzeczywistych próbek dźwiękowych, jednakże przy ich opracowaniu nie określono przedziału częstotliwości modulujących, które mogą być przez nie śledzone. Prezentowany artykuł zawiera studium pozwalające wyznaczyć brakujące przedziały częstotliwości dla trzech algorytmów śledzących: przydźwięk sieciowy, pozostałość...
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Automatic detection and correction of detuned singing system for use with query-by-humming applications
PublicationThe aim of the paper is to present an idea of using the automatic detection and correction of detuned singing as a subsystem in query-by-humming (QBH) applications. The common approach to searching for a requested song basing on the melody retrieved from hummed pattern usually employs the so-called Parsons code or melody contour. In such a case information about sound pitch is discarded. It was thought out that an additional module...
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Hearing aid fitting method based on fuzzy logic processing
PublicationWażnym etapem dopasowania współczesnych aparatów słuchowych jest wyznaczanie charakterystyki dynamiki słuchu. Charakterystyka ta wyznaczana jest na podstawie wyników testu skalowania głośności. Niestety wyniki te wyrażone są w skali kategorii głośności, natomiast aparaty słuchowe wymagają para-metrów numerycznych. Problem ten można rozwiązać za pomocą logiki rozmytej. W niniejszym referacie przedstawiono metodę przetwarzania rozmytego...
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New generation speech aid for stuttering people
PublicationWspółczesne Cyfrowe Procesory Sygnałowe (ang. DSP) mają niewielkie wymiary, ale są w stanie re-alizować złożone algorytmy. Ich dodatkową zaletą jest łatwość wymiany oprogramowania, a co za tym idzie łatwość zmiany dziedziny zastosowań. Wykorzystując możliwości procesów stało się możliwe budowanie miniaturowych protez słuchu i mowy. W referacie skupiono się na zagadnieniach związanych z projekto-wanie i implementacją algorytmów...
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Investigation of the road noise source employing an automatic noise monitoring station
PublicationThe paper presents a pilot investigation of noise source models in two selected localizations in the context of future dynamic noise map creation. The experiments were carried out using the automatic noise monitoring station engineered at the Multimedia Systems Departmentof the Gda´nsk University of Technology. The results of the noise measurements employing monitoring stations and its comparison to the reference values are depicted....
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The noise-induced harmful effect assessment based on the properties of the human hearing system
PublicationA new way of assessment of noise-induced harmful effects on human hearing system is presented in the paper. The method takes into consideration properties of the human hearing system. The pro-posed method determines the cumulative impact on hearing system produced by the excessive noise. Based on the predicted effects of the noise exposure, the new types of noise indicators were developed. The evaluation of these indicators was...
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Automatic singing quality recognition employing artificial neural networks
PublicationCelem artykułu jest udowodnienie możliwości automatycznej oceny jakości technicznej głosów śpiewaczych. Pokrótce zaprezentowano w nim stworzoną bazę danych głosów śpiewaczych oraz zaimplementowane parametry. Przy pomocy sztucznych sieci neuronowych zaprojektowano system decyzyjny, który oceniono w pięciostopniowej skali jakość techniczną głosu. Przy pomocy metod statystycznych udowodniono, że wyniki generowane przez ten system...
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Music information analysis and retrieval techniques
PublicationCelem artykułu jest przedstawienie kluczowych zagadnień gwałtownie rozwijającej się gałęzi multimediów, reprezentowanej przez systemy automatycznego wyszukiwania informacji muzycznej MIR - Music Information Retrieval, która urasta do samodzielnej dziedziny zastosowań w obrębie informatyki muzycznej. W artykule przedstawiono wybrane systemy wyszukiwania informacji muzycznej oraz przedstawiono przykład takiego systemu, zrealizowanego...
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Digital waveguide models of the panpipes
PublicationW artykule przedstawiono główne cechy syntezy falowodowej. Omówiono cechy instrumentu fletni Pana. Przedyskutowano cechy zaproponowanych dwóch modeli fletni Pana różniących się złożonością obliczeniową. Pokazano szczegóły implementacyjne tych modeli, a także uzyskane wyniki symulacji dźwięków w modelach. Dokonano porównania dźwięków rzeczywistych i uzyskanych w wyniku syntezy falowodowej.
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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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Quality Evaluation of Speech Transmission via Two-way BPL-PLC Voice Communication System in an Underground Mine
PublicationIn order to design a stable and reliable voice communication system, it is essential to know how many resources are necessary for conveying quality content. These parameters may include objective quality of service (QoS) metrics, such as: available bandwidth, bit error rate (BER), delay, latency as well as subjective quality of experience (QoE) related to user expectations. QoE is expressed as clarity of speech and the ability...