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Wyniki wyszukiwania dla: PROPAGATION IN THE SHALLOW SEA
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Postawy pracowników wobec zróżnicowania wiekowego w zespołach i organizacjach
PublikacjaArtykuł dotyczy postaw pracowników wobec zróżnicowania wiekowego w zespołach i organizacjach. W literaturze podkreśla się, że czynnikiem warunkującym efektywność takich zespołów są m.in. postawy pracowników wobec osób z innych grup wiekowych oraz wobec pracy z nimi, a ocena postaw pracowników jest niezbędna do wykorzystania właściwych metod zarządzania takim zespołem. Celem artykułu jest przedstawienie wyników badań dotyczących...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublikacjaThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Performance of Coherent Modulation Scheme Used in Acoustic Underwater Communication System
PublikacjaThe development of an acoustic underwater communication system for shallow waters is still a big scientificand construction challenge. Currently, non-coherent modulations in combination with strong channel coding are used to achieve reliable communication with low rate in such a channel. To obtain transmission with a higher transmission rate, it is required to use coherent modulation. This paper presents the assumptions of such...
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Rozprzestrzenianie się w podtorzu skutków katastrof kolejowych z udziałem materiałów niebezpiecznych
PublikacjaDuża część przewozów materiałów niebezpiecznych prowadzona jest koleją. W związku z tym bezpieczeństwo tych przewozów nabiera coraz większego znaczenia. Każda katastrofa z udziałem materiałów niebezpiecznych ma negatywny wpływ na uczestników tego zdarzenia oraz na otaczające środowisko, bowiem jej zasięg na ogół nie jest lokalny. Z tego wynika, że w przypadku zaistnienia katastrofy należy minimalizować jej skutki oraz w dalszych...
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Streaming Real-time Data in Distributed Dispatcher and Teleinformation Systems for Visualization of Multimedia Data of the Border Guard
PublikacjaSurveillance of the sea borders is a very important task for the Border Guard. Monitoring of country maritime border is an important task of the Border Guard. This task can be facilitated with the use of the technology enabling gathering information from distributed sources and its supervision and visualization. This task can be accomplished using a technology that allows to collect information from distributed sensors of different...
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Prediction of Ship Resonant Rolling - Related Dangerous Zones with Regard to the Equivalent Metacentric Height Governing Natural Frequency of Roll
PublikacjaPotentially dangerous zones corresponding to dynamical stability phenomena, possibly encountered by ships sailing in rough sea, are estimated nowadays with the use of the method recommended by IMO in the guidance coded MSC.1/Circ.1228. In this IMO method the parameter governing the natural period of roll is the initial metacentric height. Some earlier studies revealed that the initial metacentric height...
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Lokalizacja osób w środowisku promu pasażerskiego z wykorzystaniem ultra szerokopasmowego interfejsu radiowego
PublikacjaW niniejszym artykule przedstawiono badania efektywności lokalizowania poruszających się osób w środowisku promu pasażerskiego stosując pomiar czasu propagacji ultraszerokopasmowego sygnału radiowego UWB (Ultra-Wide Band) pomiędzy węzłami odniesienia i terminalem ruchomym. Opisano zbudowane stanowisko badawcze oraz uzyskane wyniki pomiarów przeprowadzonych w warunkach rzeczywistych.
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Algorithms for Ship Movement Prediction for Location Data Compression
PublikacjaDue to safety reasons, the movement of ships on the sea, especially near the coast should be tracked, recorded and stored. However, the amount of vessels which trajectories should be tracked by authorized institutions, often in real time, is usually huge. What is more, many sources of vessels position data (radars, AIS) produces thousands of records describing route of each tracked object, but lots of that records are correlated...
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Nitrogen and phosphorus compounds in coastal aquifers in Puck municipality area (northern Poland)
Publikacja1. Groundwater study shows local variations in chemical composition of selected aquifers caused by human impact The diversity is mainly manifested in • time variation of groundwater chemical composition of all analyzed parameters especially in shallow aquifers (Q1) • relationship between t he ground water chemical composition and depth of the aquifer where an inverse concentration distribution occurs higher concentrations are observed...
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Zmiany temperatury wody powierzchniowej na morzach Arktyki Rosyjskiej i ich konsekwencje dla żeglugi na Północnej Drodze Morskiej
PublikacjaPraca omawia zmiany średniej miesięcznej temperatury wody powierzchniowej na morzach Arktyki Rosyjskiej w latach 1979-2016. Stwierdzono, że w badanym okresie następował powolny wzrost SST. Jednakże tylko na Morzu Barentsa był on istotny statystycznie we wszystkich miesiącach roku (poza marcem w SE części tego morza), a w zachodniej części Morza Czukockiego w okresie od czerwca do grudnia. W dalszym ciągu na wszystkich morzach,...
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Badania i analiza uwarunkowań propagacyjnych w środowisku uprzemysłowionym
PublikacjaGłówne osiągnięcia rozprawy: - wykonanie – zgodnie z wymaganiami normatywnymi zawartymi w zaleceniach ITU-R – nowatorskich badań tłumienia sygnału radiowego na terenie Głębokowodnego Terminalu Kontenerowego (ang. Deepwater Container Terminal - DCT) w Gdańsku i zebranie obszernego materiału pomiarowego, liczącego blisko 290 tysięcy przypadków propagacyjnych, - przeprowadzenie statystycznych badań przydatności wybranych znanych modeli...
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Directed electromagnetic pulse dynamics: projecting operators method
PublikacjaIn this article, we consider a one-dimensional model of electromagnetic pulse propagation in isotropic media, takinginto account a nonlinearity of the third order. We introduce a method for Maxwell's equation transformation on thebasis of a complete set of projecting operators. The operators correspond to wave dispersion branches including thedirection of propagation. As the simplest result of applying the method, we derive a system...
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A MODEL FOR FORECASTING PM10 LEVELS WITH THE USE OF ARTIFICIAL NEURAL NETWORKS
PublikacjaThis work presents a method of forecasting the level of PM10 with the use of artificial neural networks. Current level of particulate matter and meteorological data was taken into account in the construction of the model (checked the correlation of each variable and the future level of PM10), and unidirectional networks were used to implement it due to their ease of learning. Then, the configuration of the network (built on the...
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Niezgodność przekonań i działań menedżerów wobec pracowników w wieku 55+
PublikacjaArtykuł dotyczy problematyki postaw i działań menadżerów wobec pracowników w wieku 55+. W literaturze dotyczącej zarządzania wiekiem przytaczane są wyniki badań na temat cech charakteryzujących starszych pracowników. Porównuje się je czasami z cechami przypisywanymi pracownikom młodym. Cel prezentowanych w artykule badań sformułowany został nieco inaczej i dotyczył zweryfikowania zbieżności zalet przypisywanych starszym pracownikom...
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Degradation of Polycaptolactone Modified with TPS or CaCO3 in Biotic/Abiotic Sewater
PublikacjaThe polymer degradation process in two types of water sourced from the Baltic Sea was investigated. Polycaprolactone modified with thermoplastic starch(PCL/TPS>85%) or calcium carbonate (60% PCL/40% CaCO3)and PCL alone were incubated for 28 weeks in sea water with and without microrganisms. The experimental results indicated that in each of the experiments degradation occured. The process was more effective in sea water with microorganisms.Modification...
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Guided waves for nondestructive diagnostics of embedded waveguides
PublikacjaThe thesis concentrates on comprehensive theoretical, numerical and experimental analysis of guided wave propagation in bars embedded in concrete or mortar. The investigations are focused on a particular type of objects representing a laboratory model of a ground anchor. Complex description of wave propagation phenomena in partially embedded bars is given and its application in...
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Person Tracking in a Ferry Environment Using Ultra-Wide Band Radio Interface
PublikacjaThis article presents research and analysis of effectiveness of tracking moving people in an environment of passenger ferry, using measurements of propagation time of ultra-wide band radio signal (UWB - Ultra-Wide Band). Constructed measurement stand and results of measurements carried out in a real propagation conditions were shortly discussed.
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Biodegradable polymer packaging materials - influence on environment
PublikacjaAwareness of the waste problem and its impact on the environment has awakened new interest in the area of biodegradable polymers. Biodegradation of various polymers have been studied under diverse environments like in soil, in sewage sludge, in compost conditions and in sea water by different research groups. The aim of this paper is to present the research methods on the biodegradation of the commercially available biodegradable...
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SPECTRAL DYNAMIC ANALYSIS OF A STATIONARY JACK-UP PLATFORM
PublikacjaThe paper refers to the dynamic short-term response analysis of the Baltic steel drilling platform (see Fig.2) in a random sea-state represented by one-dimensional wave spectrum proposed by Striekalov and Massel and it is recommended for the Baltic Sea area. The Baltic drilling platform is a jack-up type platform for the exploration and exploitation of oil under the Baltic Sea. The analysis presented deals with the stationary...
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Best Agers Lighthouses - strategie zarządzania wiekiem w MSP w Regionie Morza Bałtyckiego
PublikacjaW artykule podjęto problematykę zarządzania wiekiem w przedsiębiorstwach sektora MSP. Zaprezentowano założenia międzynarodowego projektu Best Agers Lighthouses - strategic age management for SME in the Baltic Sea Region realizowanego w ramach Baltic Sea Region Programme 2007-2013, współfinansowanego z Europejskiego Funduszu Rozwoju Regionalnego.
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Propozycja metody oceny bezpieczeństwa użytkowania rekreacyjnego obiektu wodnego typu ‘dzika rzeka’
PublikacjaPrzedstawiona praca dotyczy możliwości wykorzystania numerycznej symulacji przepływu do oceny bezpieczeństwa użytkowania torów rekreacyjnych występujących w wodnych parkach rozrywki. Użytkownicy licznie odwiedzanych aquaparków oczekują wyjątkowych wrażeń z jednoczesną gwarancją bezpieczeństwa. Projektowanie tych obiektów odbywa się w oparciu o przepisy zawarte w odpowiednich normach, lecz nie są one precyzyjne. Jednak wstępną weryfikację...
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A Method for Underwater Wireless Data Transmission in a Hydroacoustic Channel under NLOS Conditions
PublikacjaWireless data transmission in the hydroacoustic channel under non-line-of-sight (NLOS) propagation conditions, for example, during a wreck penetration, is difficult to implement reliably. This is mostly due to the multipath propagation, which causes a reduction in the quality of data reception. Therefore, in this work an attempt has been made to develop a reliable method of wireless underwater communication test it under the NLOS...
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Self-refraction of acoustic pulses with shock fronts in some nonequilibrium media
PublikacjaThe nonlinear self-refraction of acoustic pulsed beams, which include shock fronts, is studied. The medium of sound propagation is a gas where thermodynamically nonequilibrium processes take place, such as exothermic chemical reaction or excitation of vibrational degrees of a molecule’s freedom. Comparative analysis of the features of sound propagation over gases where pure nonlinear attenuation of the shock wave occurs, and gases...
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Ships - inspiring objects in architecture
PublikacjaSea-going vessels have for centuries fascinated people, not only those who happen to work at sea, but first and foremost, those who have never set foot aboard a ship. The environment in which ships operate is reminiscent of freedom and countless adventures, but also of hard and interesting maritime working life. The famous words of Pompey: “Navigare necesseest, vivere non estnecesse” (sailing is necessary, living – is not necessary),...
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WSPÓŁCZESNE OCHŁODZENIE REJONU SZETLANDÓW POŁUDNIOWYCH I PÓŁNOCO-ZACHODNICH KRAŃCÓW PÓŁWYSPU ANTARKTYCZNEGO
PublikacjaThe paper discusses changes of hydro-climatic conditions occurring in the South Shetland Islands and in NW parts of the Antarctic Peninsula in the 1979–2016 years period. These changes are important for evaluation of the transformation of marine and coastal ecosystems. The general feature of these changes was a transition from the strong warming phase to the cooling phase, which took place around the year 2000. The paper presents...
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MULTIEQUATION MODELS AS DIAGNOSTIC TOOLS FOR MEASURING THE OPERATIONAL FLUIDITY OF THE CONTAINER HANDLING TERMINAL
PublikacjaThe article presents the continuation of the authors’ research on the problem of the operational fluidity of cargo handling sea terminals, based on the example of the DCT. The article presents a solution based on the multiequation models and applied to analyze the operational fluidity of terminals in the transshipment and feeder relation. To provide a solution to the problem of the functioning of sea-land supply chains at the terminal,...
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Metrological analysis of precision of the system of delivering a water capsule for explosive production of water aerosol
PublikacjaIn this paper an analysis of precision of the system controlling delivery by a helicopter of water-capsule designed for extinguishing large scale fires is presented. The analysis was performed using the numerical method of distribution propagation (Monte Carlo method) supplemented with results of application of the uncertainty propagation method. In addition the optimum conditions for the airdrop are determined to ensure achievement...
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Waves Along Fractal Coastlines: From Fractal Arithmetic to Wave Equations
PublikacjaBeginning with addition and multiplication intrinsic to a Koch-type curve, we formulate and solve wave equation describing wave propagation along a fractal coastline. As opposed to examples known from the literature, we do not replace the fractal by the continuum in which it is embedded. This seems to be the first example of a truly intrinsic description of wave propagation along a fractal curve. The theory is relativistically...
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Advanced Ship Control Methods
PublikacjaThe chapter presents two main streams of research in vessel control at sea: dynamic positioning (DP) of the vessel and decision support in case of collision at sea. The control structure and basic requirements for the DP system are defined. Selected issues of automatic control of a dynamically positioned vessel are discussed. A review of advanced methods of controlling a DP ship is carried out, taking into account the tasks of...
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Acoustic field and the entropy mode induced by it in a waveguide filled with some non-equilibrium gases
PublikacjaThe non-linear propagation of an acoustic beam in a rectangular waveguide is considered. The medium of sound propagation, is a gas where thermodynamically non-equilibrium processes take place: such as exothermic chemical reactions or excitation of vibrational degrees of a molecule’s freedom. The incident and reflected compounds of the acoustic field do not interact in the leading order in the case of periodic weakly nonlinear sound...
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CAPABILITY OF IDENTIFYING AND PREDICTING THE TECHNICAL CONDITION OF PLATE HEAT EXCHANGERS IN OPERATION
PublikacjaThe paper presents a test stand for plate heat exchangers, allowing to identify the technical condition and to predict durability of the heat exchangers used aboard the sea-going ships: ”Oceanograf”, ”Władysław Orkan”and a passenger-car ferry, under the condition that they are of the same type and manufactured by the same company. In the first part three different installations with plate heat exchangers in the engine rooms...
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Database for integration of information in distributed data exchange system elements of Border Guard
PublikacjaThe paper presents the database solution for integration of information in distributed data exchange system elements of the Polish Border Guard. The proposed database solution is described in the context of data exchange system elements which control position and store identification data of vessels (fishing, sports and sailing boats) and other suspicious objects on the territorial sea, sea-coast and the internal sea-waters controlled...
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ANALIZA NUMERYCZNA WPŁYWU POZIOMU MORZA NA PRZEBIEG WEZBRAŃ W NADMORSKICH CIEKACH POWIERZCHNIOWYCH NA PRZYKŁADZIE POTOKU STRZYŻA W GDAŃSKU
PublikacjaW dzisiejszych czasach coraz większym problemem stają się podtopienia na terenach zurbanizowanych. Biorąc to pod uwagę, należy większą wagę przyłożyć do prawidłowego obliczania przepustowości koryta. Jednym z czynników wpływających na nie są warunki na odpływie. W przypadku potoków nadmorskich zależą one ściśle od poziomu morza. W pracy podjęto próbę wyznaczenia wpływu poziomu morza na przebieg wezbrań w nadmorskich ciekach powierzchniowych....
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Environmemtal Degradation of Ramie Fibre Reinforced Biocomposites
PublikacjaThe estimation of environmental degradibility of different fibre reinforced biocomposites in Baltic sea and in compost with activated sludge under natural conditions is the subject of this paper. Two types of biocomposites, ramie fibre/ecoflex and ramie fibre/cellulose nanofibre reinforced corn starch resin, were studied.It was demonstrated that the biocomposites with natural fibre of ramie were degraded in compost faster than...
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Modelling and simulations in time-fractional electrodynamics based on control engineering methods
PublikacjaIn this paper, control engineering methods are presented with regard to modelling and simulations of signal propagation in time-fractional (TF) electrodynamics. That is, signal propagation is simulated in electromagnetic media described by Maxwell’s equations with fractional-order constitutive relations in the time domain. We demonstrate that such equations in TF electrodynamics can be considered as a continuous-time system of...
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Vertical Temperature Stratification of the Gulf of Gdansk Water
PublikacjaThe Baltic Sea is characterized by variable hydroacoustic conditions, which depend on hydrological conditions throughout the year. The temperature of the water is the factor that has the greatest impact on the changes in the speed of the sound in this basin. Even at a small depth, we can observe a large temperature gradient affecting the accuracy of the conducted research using hydroacoustic devices. A characteristic feature of...
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Active Site Architecture and Reaction Mechanism Determination of Cold Adapted beta-D-galactosidase from Arthrobacter sp. 32cB
PublikacjaArthbetaDG is a dimeric, cold-adapted beta-D-galactosidase that exhibits high hydrolytic and transglycosylation activity. A series of crystal structures of its wild form, as well as its ArthbetaDG_E441Q mutein complexes with ligands were obtained in order to describe the mode of its action. The ArthbetaDG_E441Q mutein is an inactive form of the enzyme designed to enable observation of enzyme interaction with its substrate. The...
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Trees as a Shading System for Streets on the East–West Axis: Computer Simulations for the Selected Geometrical Proportions of Building Developments in Humid Continental Climate
PublikacjaThe study is aimed at investigating the possibilities for solar protection provided to the street canyon located on the E–W axis and with the following profiles: shallow (height/width (H/W) = 0.2, 0.6, and 1) and deep (H/W = 2) by two rows of trees located at a distance of 3 m away from southern and northern façades. The research was based on numerical simulation analyses conducted in the Rhinoceros® program, with the application...
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Estimation of the uncertainty of the LEM CV 3-500 transducers processing function
PublikacjaThe paper presents the methodology for estimating uncertainty of a voltage transducer processing function based on the example of LEM CV 3-500 transducer. The analysis was performed using the method based on the GUM Guide propagation of uncertainty law and the Monte Carlo numerical method. The article also presents a comparative analysis of the results of a voltage measurement evaluation done using the Monte Carlo simulation method,...
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About definition of modes and magnetosonic heating in a plasma’s flow: Especial cases of perpendicular and nearly perpendicular wave vector and magnetic field
PublikacjaDynamics of hydrodynamic perturbations in a plasma depend strongly on an angle between the wave vector and equilibrium straight magnetic field. The case of perpendicular propagation is especial. There are only two (fast) magnetosonic modes since two (slow) ones degenerate into the stationary one with zero speed of propagation. This demands individual definition of wave modes by the links of hydrodynamic relations. These links are...
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MARITIME LASER SCANNING AS THE SOURCE FOR SPATIAL DATA
PublikacjaThe rapid development of scanning technology, especially mobile scanning, gives the possibility to collect spatial data coming from maritime measurement platforms and autonomous manned or unmanned vehicles. Presented solution is derived from the mobile scanning. However we should keep in mind that the specificity of laser scanning at sea and processing collected data should be in the form acceptable in Geographical Information...
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Environmental Risk Assessment of WWII Shipwreck pollution
PublikacjaThe pollution of the sea is a global problem that has arisen as a consequence of the industrialization of the world and the intense transportation of crude oil and the products of its refinement. As sailing vessels were replaced by motor propelled ships towards the end of the 19th century, a new source of sea water pollution came into being. Every emergency involving a tanker carrying crude oil and its products is a potential source...
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Współczesne zmiany klimatyczne i ich wpływ na funkcjonowanie systemów miejskich (na przykładzie miast strefy nadmorskiej Polski)
PublikacjaThe purpose of this article is to present contemporary climatic changes in their actual scale, and to assess their impact on functioning of urban areas situated on the Polish coast. The results of the analysis of variability of hydro-climatic conditions that occurred in the last 65 years (1951-2015) in the area of the Polish coast suggest that important changes were concerning: (1) temperature of the air, and thickness and length...
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Rola GIS w badaniach środowiska morskiego
PublikacjaŚrodowisko morskie nadal pozostaje „białą plamą” z punktu widzenia systemów GIS. Trudno jest znaleźć analogie pomiędzy cyfrowym modelem terenu a danymi batymetrycznymi, ponieważ odzwierciedlają one tylko jedno z możliwych obliczy środowiska morskiego, drugim bardzo ważnym, jest falowanie. Jednakże dopiero informacja wspólna o batymetrii i falowaniu jest naprawdę wartościowa dla ludzi korzystających z morza zawodowo. Mając do dyspozycji...
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Fast Fading Characterization for Body Area Networks in Circular Metallic Indoor Environments
PublikacjaWith the increasing development of 5G and Body Area Network based systems being implemented in unusual environments, propagation inside metallic structures is a key aspect to characterize propagation effects inside ships and other similar environments, mostly composed of metallic walls. In this paper, indoor propagation inside circular metallic structures is addressed and fast fading statistical distributions parameters are obtained...
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Cache service for maps presentation in distributed information data exchange system
PublikacjaThe paper presents the proposition of caches implementation for map presentation in distributed information data exchange system. The concept of cache service is described in the context of distributed information data exchange system elements which control and present on maps positions and other identification data of vessels and other suspicious objects on the territorial sea, sea-coast and the internal sea-waters. The proposed...
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Application of RMS for damage detection by guided elastic waves
PublikacjaThis paper presents certain results of an experimental study related with a damage detection in structural elements based on deviations in guided elastic wave propagation patterns.
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INVESTIGATION INTO INTERFEROMETRIC SONAR SYSTEM ACCURACY
PublikacjaThe results of the accuracy measurements of phase differencing bathymetric sonar (PDBS) system in shallow waters are presented in the article. The measurement results were compared with the theoretical calculations for sonar system accuracy and international standards for hydrographic surveys. The proposed formulas enable to assess a priori sonar system performance using system quality factor (SQF), which takes into account influence...
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Hybrid Method Analysis of Unshielded Guiding Structures
PublikacjaA combination of mode matching, finite element methods and generalized impedance matrix is presented in a context of propagation problems for open guiding structures. The computational domain is divided into two regions: the first one is a circular cylinder containing whole guiding structure and the second one surrounds this artificial cylinder. The impedance matrix is calculated with the use of finite element method in the first...
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Application of guided waves in the evaluation of steel-concrete adhesive connection
PublikacjaThe aim of the paper is the application of guided waves in the evaluation of a condition state of adhesive connection between steel and concrete. The study concerns a push-out specimen consisting of two steel plates glued to opposite faces of a concrete cube with the use of structural adhesive. Wave propagation in the specimen without external load is investigated both experimentally and numerically. The second stage of the investigation...