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Search results for: UNDERWATER COMMUNICATION CHANNEL
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The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
PublicationPresent-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters...
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EVALUATION OF THE USE OF M2M-TYPE NB-IoT AND LTE TECHNOLOGIES FOR MARITIME COMMUNICATION SYSTEMS
PublicationThe development of IoT (the Internet of Things) wireless transmission opens a new era in communication systems. In the next years, the development and implementation of IoT systems will be very dynamic. It can be seen that the solutions of LTE – NB-IoT (Long Term Evolution – Narrowband IoT) transmission devices are implemented in a wide range of terrestrial solutions, e.g. smart grids. This paper aims to analyse the possibility...
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Remote communication in Scrum teams - a COVID-19 preventive measure or work time optimisation?
PublicationThe article presents the impact of remote work, resulting from the COVID-19 pandemic, on the functioning of Scrum teams. Attempts have been made to analyse the positive and negative aspects of remote work. The article also looks at the impact of remote work on the level of communication and efficiency of Scrum teams. For this purpose, the author conducted research on a sample of 40 organisations that declared to use Scrum methodology,...
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Local buckling of thin-walled channel member flange made of aluminum alloy
PublicationThe paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential...
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Underwater welded joint properties investigation
PublicationPrzeprowadzono badania mikro- i makroskopowe złączy spawanych typu implant wykonanych pod wodą metodą lokalnej komory suchej. Wyniki badań świadczą o tym, że w SWC badanych złączy tworzą się kruche struktury hartownicze, które są odpowiedzialne za zwiększoną skłonność stali o podwyższonej wytrzymałości do tworzenia pęknieć zimnych. Analiza rozkładów twardości złączy implant również potwierdza istnienie szkodliwego wpływu środowiska...
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Modeling Dynamics of Autonomous Underwater Vehicle.
PublicationArtykuł dotyczy budowy modelu autonomicznego pojazdu podwodnego do celów syntezy układu sterowania pojazdem. Rozważany pojazd ma długośc ok. 1 m i 30 cm średnicy. Wyposażony jest w 5 pędników, które pozwalają na sterowanie w pięciu stopniach swobody. Do badań wykorzystano model o 4 stopniach swobody. Dokonano identyfikacji parametrycznej modelu. Model zrealizowano w środowisku programowym Matlab/Simulink.
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Gender and Digital Divide - Information and Communication Technologiesand their Impact on Equality
PublicationIn the entire Europe more women than men graduate from tertiaryeducation institutes. However, they are underrepresented in scientific and engineering disciplines. Women researchers still constitute a minority in the Government and Higher Education Sectors. A number of industry reports highlight a low number of women in IT occupations49. This has led to a variety of public policy measures, such as subsidies on community provision,...
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Multimodal system for diagnosis and polysensory stimulation of subjects with communication disorders
PublicationAn experimental multimodal system, designed for polysensory diagnosis and stimulation of persons with impaired communication skills or even non-communicative subjects is presented. The user interface includes an eye tracking device and the EEG monitoring of the subject. Furthermore, the system consists of a device for objective hearing testing and an autostereoscopic projection system designed to stimulate subjects through their...
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Design of OFDM-based radio communication systems for coast-to-sea and coast-to-air propagation environments
PublicationIn the paper the study of radio communication system design process for systems based on OFDM transmission is considered. The signal propagation model for 1.4 GHz frequency band is discussed, and the study of signal propagation characteristics, important from the point of view of OFDM system design, is presented. The methodology of OFDM interface design is proposed and some characteristics of the OFDM-based radio communication...
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Effect of underwater local cavity welding method conditions on diffusible hydrogen content in deposited metal
PublicationOne of the methods with great potential for applications in underwater repairs is local cavity welding. In local cavity method, cooling conditions and diffusible hydrogen amount in weld metal are nearly the same as those existed during welding in the air. This paper presents the results of literature survey and preliminary tests of the effect of local cavity welding conditions on diffusible hydrogen amount in a deposited metal....
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An Off-Body Channel Model for Body Area Networks in Indoor Environments
PublicationThis paper presents an off-body channel model for body area networks (BANs) in indoor environments. The proposed model, which is based on both simulations and measurements in a realistic environment, consists of three components: mean path loss, body shadowing, and multipath fading. Seven scenarios in a realistic indoor office environment containing typical scatterers have been measured: five were static (three standing and two...
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Study on Speech Transmission under Varying QoS Parameters in a OFDM Communication System
PublicationAlthough there has been an outbreak of multiple multimedia platforms worldwide, speech communication is still the most essential and important type of service. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission, based most often on multi-valued modulations, multiple...
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Event-Triggered Communication in Cooperative, Adaptive Model Predictive Control of a Nuclear Power Plant’s Turbo–Generator Set
PublicationThis paper discusses the issue of optimizing the communication between the components of a cooperating control system formed by a pair of MPC controllers of a nuclear power plant turbine set using online recursive least squares identification. It is proposed to use event-triggered communication, i.e., sending information only at selected time instants, as opposed to the standard approach where communication is triggered by time...
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Next generation ITS implementation aspects in 5G wireless communication network
PublicationIn the paper the study of Intelligent Transportation systems implementation in the 5G wireless communication network is presented. Firstly, small-cell concept in Ultra Dense Heterogeneous network was analyzed. Secondly, the 5G network requirements were presented which are important from the point of view of transportation systems development. Next, the study on the 5G network architectures proposals dedicated to the ITS systems...
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Transmission properties of a shallow hydroacoustic channel.
PublicationWielokrotne odbicia fali akustycznej od granic ośrodka są przyczyną poważnych ograniczeń możliwości transmisyjnych w płytkich kanałach hydroakustycznych. Zastosowanie modelu BNM kanału, należącego do rezultatów międzynarodowego projektu PROSIM tworzonego w ramach inicjatywy MAST-III, pozwoliło obliczyć funkcje odpowiedzi impulsowych kanału i przeprowadzić symulację transmisji sygnału cyfrowego. Artykuł prezentuje wyniki transmisji...
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Risk Modelling for Passages in Approach Channel
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Radio Channel Measurements in 868 MHz Off-Body Communications in a Ferry Environment
PublicationIn this paper, a characterization of the 868 MHz off-body radio channel in BANs is presented. Measurements were carried out in a ferry environment using a specific set-up. A method for path loss using radio distance measurements (RDMs) was developed. It allows to automate the measurements process and make it independent from the variable speed of a moving person. Based on the observed path loss as a function of distance, the obtained...
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Scholarly communication activities in the fields of chemistry and economics. A Polish perspective
PublicationThis study examines the scholarly communication activities in two scientific fields, chemistry and economics, in a Polish context. The dissertation aims at investigating what characterises the publishing choices of researchers and what supplementary forms for the dissemination of research output are used by scholars. In addition, the paper is looking into what are the views and awareness of open access and institutional repositories...
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Radio Channel Measurements in Off-Body Communications in a Ferry Passenger Cabin
PublicationThis paper presents an off-body radio channel measurements in a ferry passenger cabin at 2.45 GHz band, for static sleeping scenarios with different body orientation and on-body antennas placements, and also for upper and lower sleeping berths. The measurements have been performed with two types of on-body wearable receiving antennas: FlexPIFA (flexible planar inverted F antenna), and FlexNotch (flexible adhesive-backed notch antenna)...
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A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublicationIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
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Local buckling of compressed flange of cold-formed channel members made of aluminum alloy
PublicationThe paper deals with local buckling of a compressed single flange of thin-walled channel cold- formed columns and beams made of aluminum alloy. Material is described by means of the Ramberg-Osgood constitutive equation. Axial compression of the columns and beams undergoing bending is taken into consid- eration. A simple model of the member flange in the form a long beam elastically connected to the web is used to find the critical...
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Buckling and initial post-local buckling behaviour of cold-formed channel member flange
PublicationThe initial post-buckling behaviour of a cold-formed channel member flange after its local buckling is investigated. An axially compressed column or beam subjected to pure bending is considered. The member material is assumed to follow a linear stress-strain relationship. The governing non-linear differential equation of the problem is derived using the minimum total potential energy principle. An approximate solution for the equation...
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Linux scheduler improvement for time demanding network applications, running on Communication Platform Systems
PublicationCommunication Platform Systems as ex. ATCA standard blades located in standardized chassis provides high level communication services between system peripherals. Each ATCA blade brings dedicated functionality to the system but can as well exist as separated host responsible for servicing set of task. According to platform philosophy these parts of system can be quite independent against another solutions provided by competitors....
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LABORATORY STAND FOR INVESTIGATIONS OF THE QUICK - CHANGING TEMPERATURE OF GAS FLOWING IN THE PISTON COMPRESSOR OUTLET CHANNEL
PublicationThis paper presents a laboratory stand, created as a part of work on the doctor dissertation, intended for investigation of heat and flow processes taking place in the Espholin H3S piston compressor outlet channel. The test stand elements and their configuration within the stand are described. Discussed are also problems connected with the quick-changing measurement technique, solutions which have been proposed so far in that technology...
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Multimodal Approach For Polysensory Stimulation And Diagnosis Of Subjects With Severe Communication Disorders
Publicationis evaluated on 9 patients, data analysis methods are described, and experiments of correlating Glasgow Coma Scale with extracted features describing subjects performance in therapeutic exercises exploiting EEG and eyetracker are presented. Performance metrics are proposed, and k-means clusters used to define concepts for mental states related to EEG and eyetracking activity. Finally, it is shown that the strongest correlations...
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Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning
PublicationFollowing the continuous development of the information technology, the concept of dense urban networks has evolved as well. The powerful tools, like machine learning, break new ground in smart network and interface design. In this paper the concept of using deep learning for estimating the radio channel parameters of the LTE (Long Term Evolution) radio interface is presented. It was proved that the deep learning approach provides...
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Numerical Analysis of Turbulent Flow over a Backward-facing Step in an Open Channel
PublicationComputational examinations of the flow field in an open channel having a single Backward--Facing Step (BFS) with a constant water depth of 1.5 m were performed. The effects of the expansion ratio, and the flow velocity along the reattachment length, were investigated by employing two different expansion ratios of 1.5 and 2, and eight various flow velocities of 0.5, 1, 2, 3, 4, 5, 7.5 and 10 m/sec in the Computational Fluid Dynamic...
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Hybrid Laboratory of Radio Communication With Online Simulators and Remote Access
PublicationContribution: Two toolsets for the remote teaching of radio communication laboratory classes: 1) online simulators for individual work of students and 2) a remote access system to laboratory workstations for group work. Initial assumptions and method of implementation of both tools are presented. Background: The COVID-19 pandemic has forced a change in teaching at all levels of education. The specificity of practical classes, such...
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Selected local stability problems of channel section flanges made of aluminium alloys
PublicationThe paper addresses the issue of local buckling of compressed flanges of cold-formed thin-walled channel columns and beams with nonstandard flanges composed of aluminium alloys. The material behaviour follows the Ramberg–Osgood law. It should be noted that the proposed solution may be also applied for other materials, for example: stainless steel, carbon steel. The paper is motivated by an increasing interest in nonstandard cold-formed...
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Marek Czachor prof. dr hab.
People -
Communication and Negotiations 21/22
e-Learning Courses -
Communication and Negotiations 22/23
e-Learning Courses -
Communication and Negotiations 23/24
e-Learning Courses -
New methods of underwater ship noise classification
PublicationDetekcja, klasyfikacj, identyfikacja i rozpoznanie cech hałasu generowanego przez statki jest bardzo istotna z punku widzenia naukowego i obronnego. Włożono wiele wysiłku w rozwój technologii sonarów pasywnych, która umożliwia zastosowanie hałasów podwodnych do celów praktycznych. Przedstawiono wyniki badań, które ukazują możliwości wykorzystania sieci neuronowej do klasyfikacji źródeł generowanych przez układy mechaniczne, odpowiadających...
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Synthesis of autonomous underwater vehicle control system.
PublicationArtykuł dotyczy parametrycznej identyfikacji systemu sterowania autonomicznego pojazdu podwodnego.Badania opierają sie na modelu pojazdu o 4 stopniach swobody, zrealizowanym w środowisku programowym Matlab/Simulink. Zastosowano wielowymiarowy nieliniowy regulator PID. Przedstawiono wyniki symulacji zaprojektowanego układu sterowania.
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OFDM modulation and adaptive equalisation for underwater communications.
PublicationWłasności transmisyjne płytkiego kanału podwodnego są ograniczone ze względu na wielokrotne odbicia fal dźwiękowych od dna i powierzchni wody oraz ze względu na niestacionarność powodowaną głównie przez ruch powierzchni wody. W celu minimalizacji wpływu interferencji międzysymbolowych, powodowanych przez wielodrogową propagację fal dźwiękowych, w tradycyjnych wąskopasmowych modemach telekomunikacyjnych stosowane są złożone equalizery...
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Weldability of high strength steel in underwater environment
PublicationThe article describes the problems with weldability of high-strength steels in the aquatic environment. The tendency of steel S355J2G3 and S500M to form cold cracks when welded in wet welding conditions has been experimentally evaluated. It was found that the tested steels have a high propensity to cracking. An experiment has been proposed and tested to evaluate the usefulness of the tempering bead technique as a method of improving...
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A parametric method for preliminary determination of underwater vehiclesdeadweight
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RECODIS: Resilient Communication Services Protecting End-user Applications from Disaster-based Failures
PublicationDisaster-based failures can seriously disrupt any communication network, making its services unavailable. Such disruptions may be caused by natural disasters, technology-related failures, or malicious attacks, and they are observably increasing in number, intensity and scale. When network services that are a part of critical infrastructure become unavailable, commercial and/or societal problems are inevitable. The issue of limiting...
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The selected hydrotechnical conditions of the Dnieper – Bug Channel and the Pripyat River in the development of the International Waterway E40
PublicationInternational waterway E40 (MDW E40) is included in the network of inland waterways of transnational importance. It is a link between two areas: the Baltic Sea and the Black Sea. E40 route runs through three countries: Poland, Belarus and Ukraine. The article presents the results of the study on the analysis of two very important sections of the MDW E40 on the Belarusian section, it is:. the Dnieper – Bug Channel and the Pripy...
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Inverse Integration of the Open Channel Flow Equations
PublicationW artykule przedstawiono metodę obliczeń umożliwiającą całkowanie równań przepływu nieustalonego w kanałach otwartych (równań de Saint Venanta) wstecz. Dyskutowano także przydatność równania retencji w zagadnieniu sterowania przepływem.
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Safety of Single-Channel Railway Traffic Control
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Transmission of digital signals in a nonstationary hydroacoustic channel.
PublicationZ telekomunikacyjnego punktu widzenia właściwości transmisyjne kanału hydroakustyczny są ograniczone przez występowanie wielokrotnych odbić fali dźwiękowej od dna i powierzchni wody oraz niestacjonarność wprowadzaną głównie przez ruch powierzchni wody. Artykuł przedstawia model własności transmisyjnych kanału. Wprowadzono niestacjonarność do odpowiedzi impulsowych kanału przez założenie przypadkowej zmienności czasów przyjścia...
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Measuring the effectiveness of digital communication - social media performance: an example of the role played by AI-assisted tools at a university
PublicationThe aim of the article is to show the role played by AI-powered tools in measuring the effectiveness of digital communication in social media using a university case study. Therefore, a research problem was formulated to identify the metrics (KPIs) used to measure the effectiveness – non-financial outcomes – of digital social media communication at the university using AI tools. The literature review on the role of AI in digital...
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Effect of underwater friction stir welding parameters on AA5754 alloy joints: experimental studies
PublicationThe water as a welding environment may generate serious technological and metallurgical problems but in certain cases, the physicochemical properties of water can be used effectively, e.g., to impart the specific properties of welded materials. The purpose of the work was verification of effectiveness of the water cooling of aluminium alloy AA5754 for various sets of technological parameters of underwater friction stir welding...
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Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
PublicationApplication of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency...
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Lax-Wendroff and McCormack Schemes for Numerical Simulation of Unsteady Gradually and Rapidly Varied Open Channel Flow
PublicationTwo explicit schemes of the finite difference method are presented and analyzed in the paper. The applicability of the Lax-Wendroff and McCormack schemes for modeling unsteady rapidly and gradually varied open channel flow is investigated. For simulation of the transcritical flow the original and improved McCormack scheme is used. The schemes are used for numerical solution of one dimensional Saint-Venant equations describing free...
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A Time Delay Controller Included Terminal Sliding Mode and Fuzzy Gain Tuning for Underwater Vehicle-Manipulator Systems
PublicationAn improved Time Delay Control (TDC) method for an Underwater Vehicle-Manipulator System (UVMS) is proposed. The proposed controller consists of three terms: a time-delay-estimation term that cancels nonlinearities of the UVMS dynamics, a Terminal Sliding Mode (TSM) term that provides a fast response and a PID term that reduces the tracking error. In addition the proposed controller uses fuzzy rules to adaptively tune the gains...
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The dynamics of the total outputs of Japanese information and communication technology sectors: A further study
PublicationThe purpose of this study is to continue the previous studies which discussed the impacts of the changes of final demands on the total outputs of the Information and Communication Technology (ICT) sectors of the specific country. More specifically, this study aims to conduct a deeper analysis regarding these impacts. This study focuses on the case of Japan. This study employs a demand-pull Input-Output (IO) quantity model, one...
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3D Object Shape Reconstruction from Underwater Multibeam Data and Over Ground Lidar Scanning
PublicationThe technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation,...