Filtry
wszystkich: 1303
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: underwater acoustic communications
-
Prognozowanie właściwości złączy spawanych pod wodą metodą lokalnej komory suchej
PublikacjaNiniejsza praca jest poświęcona spawaniu pod wodą metodą lokalnej komory suchej (MLKS) i przedstawia metodologię oraz narzędzia umożliwiające prognozowanie właściwości złączy spawanych wykonanych przy zastosowaniu tej odmiany spawania. Monografia zawiera opis rozwoju spawania pod wodą oraz charakterystykę metod wykorzystywanych do realizacji prac spawalniczych. Zaproponowano nowy podział metod spawania pod wodą, uwzględniający...
-
Measurements and visualization of sound field distribution around organ pipe
PublikacjaMeasurements and visualization of acoustic field around an organ pipe are presented. Sound intensity technique was applied for this purpose. Measurements were performed in free field. The organ pipe was activated with a constant air flow, produced by an external compressor, aimed at obtaining long-term steady state responses of generated acoustic signal. Sound energy distribution was measured in a defined fixed grid of points...
-
Modeling and Designing Acoustical Conditions of the Interior – Case Study
PublikacjaThe primary aim of this research study was to model acoustic conditions of the Courtyard of the Gdańsk University of Technology Main Building, and then to design a sound reinforcement system for this interior. First, results of measurements of the parameters of the acoustic field are presented. Then, the comparison between measured and predicted values using the ODEON program is shown. Collected data indicate a long reverberation...
-
International Conference on Communications in Computing
Konferencje -
IEEE Computer Communications Workshop
Konferencje -
IEEE International Conference on Communications
Konferencje -
IEEE Symposium on Computers and Communications
Konferencje -
Asia Pacific Conference on Communications
Konferencje -
Nonlinear Influence of Sound on the Vibrational Energy of Molecules in a Relaxing Gas
PublikacjaDynamics of a weakly nonlinear and weakly dispersive flow of a gas where molecular vibrational relaxation takes place is studied. Variations in the vibrational energy in the field of intense sound is considered. These variations are caused by a nonlinear transfer of the acoustic energy into energy of vibrational degrees of freedom in a relaxing gas. The final dynamic equation which describes this is instantaneous, it includes a...
-
Marek Biziuk prof. dr hab. inż.
OsobyUr. 25.06.1947 w Sokółce, Województwo Podlaskie. W latach 1964-1969 studiował na Wydziale Chemicznym PG. Stopień doktora nauk technicznych uzyskał w 1977 r., a stopień doktora habilitowanego nauk chemicznych w zakresie chemia uzyskał na Wydziale Chemicznym PG 24.05.1995 r. Tytuł naukowy profesora nauk chemicznych uzyskał na Wydz. Chemicznym PG 6.04.2001 r. Członek Komitetu Chemii Analitycznej PAN od 2008, członek Zespołu ds....
-
Design of Resilient Vehicle-to-Infrastructure Systems
PublikacjaVehicular ad hoc networks (VANETs) have recently gained noticeable attention due to advantages in improving road traffic safety, shaping the road traffic and providing infotainment opportunities to travellers. However, transmission characteristics following from the IEEE 802.11p standard and the high mobility of VANET nodes remarkably reduce the lifetime, reach and capacity of wireless links, and often lead to simultaneous disruptions...
-
Międzysystemowa kompatybilność elektromagnetyczna radia impulsowego
PublikacjaW referacie przedstawiono uwarunkowania kompatybilnościowe transmisji ultraszerokopasmowej, z uwzględnieniem wymagań FCC (Federal Communications Commission). W szczególności scharakteryzowano system radia impulsowego oraz kształtowania widma częstotliwości zajmowanego przez transmisję impulsową.
-
Split-beam echosounder data from Puck Bay winter 2019
Dane BadawczeThe acoustic data was collected in 2019, in the Bay of Puck, in the season: winter. Data was collected during the day and night. Three split-beam echosounders with frequencies of 38 kHz, 120 kHz and 333 kHz were used to collect the data. The data was collected at a designated study area not far from the city of Hel, on the route Hel - Gdynia and on...
-
An facile Fortran-95 algorithm to simulate complex instabilities in three-dimensional hyperbolic systems
Dane BadawczeIt is well know that the simulation of fractional systems is a difficult task from all points of view. In particular, the computer implementation of numerical algorithms to simulate fractional systems of partial differential equations in three dimensions is a hard task which has no been solved satisfactorily. Here, we provide a Fortran-95 code to solve...
-
Dariusz Dąbrowski dr hab. inż.
OsobyDariusz Dąbrowski ukończył studia w Instytucie Okrętowym Politechniki Gdańskiej, a w 1987 roku podjął pracę na tej uczelni na stanowisku asystenta w Zakładzie Organizacji Przemysłu Okrętowego w ówczesnym Instytucie Organizacji i Projektowania Systemów Produkcyjnych. W 1990 roku wyjechał na stypendium TEMPUS, UE, i spędził 14 miesięcy na Uniwersytecie w Sheffield, gdzie uczestniczył w programie Master of Business Administration...
-
Sound intensity distribution around organ pipe
PublikacjaThe aim of the paper was to compare acoustic field around the open and stopped organ pipes. The wooden organ pipe was located in the anechoic chamber and activated with a constant air flow, produced by an external air-compressor. Thus, long-term steady state response was possible to obtain. Multichannel acoustic vector sensor was used to measure the sound intensity distribution of radiated acoustic energy. Measurements have been...
-
Selective monitoring of noise emitted by vehicles involved in road traffic
PublikacjaAn acoustic intensity probe was developed measures the sound intensity in three orthogonal directions, making possible to calculate the azimuth and elevation angles, describing the sound source position. The acoustic sensor is made in the form of a cube with a side of 10 mm, on the inner surfaces of which the digital MEMS microphones are mounted. The algorithm works in two stages. The first stage is based on the analysis of sound...
-
Some fundamental aspects of self-levitating sliding contact bearings and their practical implementations
PublikacjaIn this study, fundamental aspects and mechanisms of acoustic levitation together with governing equations are presented first. Then, the acoustic levitation phenomenon is considered as a new way to design air suspension systems capable of self-levitation. A particular emphasis is laid on journal bearings and their specific geometrical configuration. A practical feasibility of using acoustic levitation to separate contacting surfaces...
-
A taxonomy of challenges to resilient message dissemination in VANETs
PublikacjaInter-vehicular communications is seen as a promising solution to a number of issues related with public road safety, road congestion management, and infotainment. However, Vehicular Ad-hoc NETworks (VANETs) characterized by high mobility of vehicles and facing a number of other issues related with high frequency wireless communications and network disconnections, encounter major challenges related with reliability of message delivery....
-
Akustyka sali koncertowej Szkoły Muzycznej w Gdyni - projekt i realizacja
PublikacjaOmówiono zakres współpracy architekta, akustyka i projektanta wnętrza na przykładzie sali koncertowej Szkoły Muzycznej w Gdyni. Wskazano różnice między projektem akustycznym sali i projektem wnętrza. Podano zasady akustycznego projektowanie sali widowiskowej oraz znaczenie rozproszenia dźwięku dla jakości akustycznej sali. Przedstawiono zasady indywidualnego konstruowania ustrojów rozpraszających dźwięk oraz dostępne na rynku ustroje...
-
Non linear identification of underwater vehicles. W: [CD-ROM] Conference Proceedings. The 29th Israel Conference on Mechanical Engineering. May 12-13, 2003 Haifa, Israel. Haifa: Technion - Israel Inst. Technol.**2003[B8] s. 1-8, 5 rys. bibliogr. 7 poz. Nieliniowa identyfikacja pojazdów podwodnych.
PublikacjaArtykuł dotyczy identyfikacji nieliniowych modeli pojazdów podwodnych o wie-lu zmiennych. Zaproponowana metoda działa w obszarze czasu rzeczywistego imoże być stosowana do nieliniowych modeli, które są liniowe w części doty-czącej nieznanego wektora parametrów. W celu poradzenia sobie z parametramizmieniającymi się w czasie, zastosowano rekursyjną wersję algorytmu identy-fikacji. Po krótkim opisie matematycznych podstaw...
-
Non-Wave Variations in Temperature Caused by Sound in a Chemically Reacting Gas
PublikacjaA weakly nonlinear generation of non-acoustic modes in the field of sound in a gas is considered. An exotericchemical reaction of A->B type, which takes place in a gas, may be reversible or not. Two types of sound areconsidered, low-frequency and high-frequency as compared with the characteristic time of a chemical reaction.For both these cases, the governing equations of non-acoustic modes are derived and conclusions of the efficiencyof...
-
Split-beam echosounder data from Puck Bay autumn 2018 Part II
Dane BadawczeThe acoustic data was collected in 2018, in the Bay of Puck, in the seasons: autumn. Data was collected during the day and night. Three split-beam echosounders with frequencies of 38 kHz, 120 kHz and 333 kHz were used to collect the data. The data was collected at a designated study area not far from the city of Hel and on the route Hel - Gdynia while...
-
Processing of acoustical data in a multimodal bank operating room surveillance system
PublikacjaAn automatic surveillance system capable of detecting, classifying and localizing acoustic events in a bank operating room is presented. Algorithms for detection and classification of abnormal acoustic events, such as screams or gunshots are introduced. Two types of detectors are employed to detect impulsive sounds and vocal activity. A Support Vector Machine (SVM) classifier is used to discern between the different classes of...
-
Temper bead welding of S420G2+M steel in water environment
PublikacjaThe article presents the idea of the use of Temper Bead Welding (TBW) technique to improve the weldability of high strength steel at underwater wet welding conditions. Wet welding method with the use of covered electrodes is described. This work shows results of metallographic examinations and hardness measurements of samples of S420G2+M steel with weld beads performed under water. It has been shown that Temper Bead Welding technique...
-
IEEE International Conference on Computer Communications
Konferencje -
International Conference on Information and Communications Security
Konferencje -
International Conference on Advanced Computing and Communications
Konferencje -
International Conference on Advanced Communications and Computation
Konferencje -
IFIP International Conference on Broadband Communications
Konferencje -
The International Conference on Future Networks and Communications
Konferencje -
International Symposium on Networks, Computers and Communications
Konferencje -
IEEE Wireless Communications and Networking Conference
Konferencje -
International Conference on Information and Communications Technology
Konferencje -
Cultural Attitudes towards Technology and Communications
Konferencje -
IEEE Consumer Communications and Networking Conference
Konferencje -
ACM Conference on Computer and Communications Security
Konferencje -
Precise Bathymetry as a Step Towards Producing Bathymetric Electronic Navigational Charts for Comparative (Terrain Reference) Navigation
PublikacjaBathymetric Electronic Navigational Charts (bENCs) contain only bathymetry data and can be used in applications such as underwater positioning, dredging and piloting. According to International Hydrographic Organization (IHO) standard S-57, Electronic Navigational Charts (ENCs) contain depth information with pure density of depth contours. Typical depth contours encoded by Hydrographic Offices are limited to 2, 5, 10 and 20 m....
-
Temper bead welding of S460N steel in wet welding conditions
PublikacjaWet welding is the most common method of welding in water environment. It is most often used for repairing of underwater parts of offshore structures. However, the water as a welding environment causes an increase of susceptibility of steels to cold cracking. For underwater constructions high strength low alloy (HSLA) steel are widely used. In wet welding condition a HSLA steel is characterized by high susceptibility to cold cracking....
-
Zdzisław Kowalczuk prof. dr hab. inż.
OsobyW 1978 ukończył studia w zakresie automatyki i informatyki na Wydziale Elektroniki Politechniki Gdańskiej, następnie rozpoczął pracę na macierzystej uczelni. W 1986 obronił pracę doktorską, w 1993 habilitował się na Politechnice Śląskiej na podstawie pracy Dyskretne modele w projektowaniu układów sterowania. W 1996 mianowany profesorem nadzwyczajnym, w 2003 otrzymał tytuł profesora nauk technicznych. W 2006 założył i od tego czasu...
-
The publication of the European Commission's guidelines in an official language of a new Member State as a condition for their application.Case comment to the order of the Polish Supreme Court of 3 September 2009 (Ref. No. III SK 16/09) to refer a preliminary question to the Court of Justice of the European Union (C-410/99 Polska Telefonia Cyfrowa sp. z o.o. v Prezes Urzędu Komunikacji Elektronicznej)
PublikacjaThe case comment concentrates on two issues. In the first place, it contains an analysis of the legal character of the European Commission Guidelines on market analysis and the assessment of significant market power under the Community regulatory framework for electronic communications networks and services. Secondly, it analyses the consequences of the lack of publication of those Guidelines in Polishlanguage in the Official Journal...
-
Asia Conference on Information, Computer and Communications Security (ACM Symposium on Information, Computer and Communications Security)
Konferencje -
Monitoring of Caged Bluefin Tuna Reactions to Ship and Offshore Wind Farm Operational Noises
PublikacjaUnderwater noise has been identified as a relevant pollution affecting marine ecosystems in different ways. Despite the numerous studies performed over the last few decades regarding the adverse effect of underwater noise on marine life, a lack of knowledge and methodological procedures still exists, and results are often tentative or qualitative. A monitoring methodology for the behavioral response of bluefin tuna (Thunnus thynnus)...
-
A double-talk detector using audio watermarking
Publikacjaa novel approach to double-talk detection in the acoustic echo canceler is proposed. a hidden signature is embedded into the arriving signal, using the echo-hiding method. next detection of the presence of this signature in the microphone signal is performed. the results of the signature detection may be used by the acoustic echo canceler to stop or restart the adaptation process.
-
Nonlinear properties of the Gotland Deep – Baltic Sea
PublikacjaThe properties of the nonlinear phenomenon in water, including sea water, have been well known for many decades. The feature of the non homogeneous distribution of the speed of sound along the depth of the sea is very interesting from the physical and technical point of view. It is important especially in the observation of underwater area by means of acoustical method ( Grelowska et al ., 2013; 2014). The observation of the underwater...
-
Highlighting interlanguage phoneme differences based on similarity matrices and convolutional neural network
PublikacjaThe goal of this research is to find a way of highlighting the acoustic differences between consonant phonemes of the Polish and Lithuanian languages. For this purpose, similarity matrices are employed based on speech acoustic parameters combined with a convolutional neural network (CNN). In the first experiment, we compare the effectiveness of the similarity matrices applied to discerning acoustic differences between consonant...
-
Acoustical images of the Gulf of Gdansk
PublikacjaAcoustic images of seabed are of interest to specialists in the field of marine engineering, marine navigation, marine archeology, hydrogeology, etc. New technolo gies based on use of elastic waves, predominantly acoustic waves that allow detecting complexity of geometric forms of seabed, ensure progress in studying the bathymetric structure of seafloor. Use of parametric sources of waves generated...
-
Hysteresis curves and loops for harmonic and impulse perturbations in some non-equilibrium gases
PublikacjaEvolution of sound in a relaxing gas whose properties vary in the course of wave propagation, is studied. A relaxing medium may reveal normal acoustic properties or be acoustically active. In the first case, losses in acoustic energy lead to an increase in internal energy of a gas similarly as it happens in Newtonian fluids. In the second case, acoustic energy increases in the course of sound propagation, and the internal energy...
-
The Positioning Accuracy of BAUV Using Fusion of Data from USBL System and Movement Parameters Measurements
PublikacjaThe article presents a study of the accuracy of estimating the position coordinates of BAUV (Biomimetic Autonomous Underwater Vehicle) by the extended Kalman filter (EKF) method. The fusion of movement parameters measurements and position coordinates fixes was applied. The movement parameters measurements are carried out by on-board navigation devices, while the position coordinates fixes are done by the USBL (Ultra Short Base...
-
generation of the vorticity mode by sound in a bingham plastic
PublikacjaThis study investigates interaction between acoustic and non-acoustic modes, such as vorticity mode,in some class of a non-newtonian fluid called Bingham plastic. The instantaneous equations describinginteraction between different modes are derived. The attention is paid to the nonlinear effects in the fieldof intense sound. The resulting equations which describe dynamics of both sound and the vorticity modeapply to both periodic...