Wyniki wyszukiwania dla: HYDROACOUSTIC CHANNEL

• System identification theory-based estimation of underwater acoustic channel for broadband communications.

  Publikacja

  • I. Kochańska
  • H. Lasota
  • R. Salamon

  - Rok 2005

  Płytki kanał podwodny jest niestacjonarny z powodu wielokrotnych odbić fal dźwiękowych od powierzchni wody oraz ruchu nadajnika i odbiornika systemu komunikacyjnego. Dla zapewnienia szybkiej transmisji danych niezbędna jest estymacja kanału oparta na equalizacji adaptacyjnej. W systemach komunikacji podwodnej stosowane są zazwyczaj equalizery DFE z zaimplementowanymi algorytmami najmniejszych kwadratów: LMS oraz RLS.W artykule...

• A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments

  Publikacja

  • F. D. Cardoso
  • M. M. Ferreira
  • S. J. Ambroziak
  • L. M. Correia

  - IEEE Access - Rok 2021

  In 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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• Numerical Analysis of Turbulent Flow over a Backward-facing Step in an Open Channel

  Publikacja

  • B. K. M. Saleem
  • A. M. Mustafa
  • D. A. Kareem
  • M. I. Yüce
  • M. Szydłowski

  - Archives of Hydro-Engineering and Environmental Mechanics - Rok 2023

  Computational 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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• Selected local stability problems of channel section flanges made of aluminium alloys

  Publikacja

  • M. Kujawa

  - CONTINUUM MECHANICS AND THERMODYNAMICS - Rok 2020

  The 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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• Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning

  Publikacja

  • K. Cwalina
  • P. Rajchowski
  • A. Olejniczak
  • O. Błaszkiewicz
  • R. Burczyk

  - SENSORS - Rok 2021

  Following 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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• Adaptive Identification of Underwater Acoustic Channel with a Mix of Static and Time-Varying Parameters

  Publikacja

  • M. Niedźwiecki
  • A. Gańcza
  • L. Shen
  • Y. Zakharov

  - Rok 2022

  We consider the problem of identification of communication channels with a mix of static and time-varying parameters. Such scenarios are typical, among others, in underwater acoustics. In this paper, we further develop adaptive algorithms built on the local basis function (LBF) principle resulting in excellent performance when identifying time-varying systems. The main drawback of an LBF algorithm is its high complexity. The subsequently...

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• ADAPTIVE IDENTIFICATION OF TIME-VARYING IMPULSE RESPONSE OF UNDERWATER ACOUSTIC COMMUNICATION CHANNEL

  Publikacja

  • I. Kochańska

  - HYDROACOUSTICS - Rok 2015

  The transmission properties of underwater acoustic communication channel can change dynamically due to the movement of acoustic system transmitter and receiver or underwater objects reflecting transmitted signal. The time-varying impulse response measurement and estimation are necessary to match the physical layer of data transmission to instantaneous channel propagation conditions. Using the correlative measurement method, impulse...

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• Underwater Acoustic Communications in Time-Varying Dispersive Channels

  Publikacja

  • I. Kochańska
  • J. Schmidt
  • M. Rudnicki

  - Rok 2016

  Underwater acoustic communication (UAC) system designers tend to transmit as much information as possible, per unit of time, at as low as possible error rate. However, the bit rate achieved in UAC systems is much lower than for wire or radio-communication systems. This is due to disadvantageous properties of the UAC channels, namely the sea and inland waters. Estimation of UAC channel transmission properties is possible within...

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• Ultrawideband transmission in physical channels: a broadband interference view

  Publikacja

  • H. Lasota
  • I. Kochańska
  • R. Mazurek

  - HYDROACOUSTICS - Rok 2014

  The superposition of multipath components (MPC) of an emitted wave, formed by reflections from limiting surfaces and obstacles in the propagation area, strongly affects communication signals. In the case of modern wideband systems, the effect should be seen as a broadband counterpart of classical interference which is the cause of fading in narrowband systems. This paper shows that in wideband communications, the time- and frequency-domain...

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• Capturing nonexponential dynamics in the presence of two decay channels

  Publikacja

  • F. Giacosa
  • P. Kościk
  • T. Sowiński

  - Physical Review A - Rok 2020

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• Experimental investigations on condensation in flow in small diameter channels

  Publikacja

  • D. Mikielewicz
  • M. Klugmann
  • J. Wajs

  - Rok 2011

  W pracy przedstawiono innowacyjne podejście do eksperymentalnych badań kondensacji w przepływie oraz omówiono wstępne wyniki badań eksperymentalnych kondensacji etanolu w pionowej rurce srebrnej o średnicy wewnętrznej 2.3 mm.

• Decoherence-free communication over multiaccess quantum channels

  Publikacja

  • M. Demianowicz

  - OPEN SYSTEMS & INFORMATION DYNAMICS - Rok 2013

  In this paper we consider decoherence-free communication over multiple access and k-user quantum channels. First, we concentrate on a hermitian unitary noise model U for a two-access bi-unitary channel and show that in this case a decoherence-free code exists if the space of Schmidt matrices of an eigensubspace of U exhibits certain properties of decomposability. Then, we show that our technique is also applicable for generic random unitary...

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• Local buckling and initial post-buckling behaviour of channel member flange - analytical approach

  Publikacja

  • C. K. Szymczak

  - Rok 2016

  The local buckling and initial post-buckling behaviour of the cold-formed channel member flange is investigated. The governing nonlinear differential equation for axially compressed columns and beams undergoing pure bending is derived using the stationary total potential energy principle. The critical stress and initial post-buckling equilibrium path is determined by means of a perturbation approach. The results obtained allow...

• Stationary underwater channel experiment: Acoustic measurements and characteristics in the Bornholm area for model validations

  Publikacja

  • I. Nissen
  • I. Kochańska

  - HYDROACOUSTICS - Rok 2016

  The underwater acoustical channel is time-variant, and even on small time scales there is often existing no ‘acoustical frozen ocean’. Popular is the use of WSSUS-channel transmission modeling (Wide-Sense Stationary Uncorrelated Scattering) for the stochastic description of bandpass signals in GSM mobile phones with moving participants; since this results in a halved number of model parameters. For underwater sound applications...

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• Local buckling of compressed flange of cold-formed channel members made of aluminum alloy

  Publikacja

  • M. Kujawa
  • C. K. Szymczak

  - Rok 2018

  The 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...

• Numerical Analysis of Steady Gradually Varied Flow in Open Channel Networks with Hydraulic Structures

  Publikacja

  • W. Artichowicz
  • D. Gąsiorowski

  - Rok 2018

  In this paper, a method for numerical analysis of steady gradually varied fl ow in channel networks with hydraulic structures is considered. For this purpose, a boundary problem for the system of ordinary differential equations consisting of energy equation and mass conservation equations is formulated. The boundary problem is solved using fi nite difference technique which leads to the system of non-linear algebraic equations....

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• Bedload transport and temporal variation of non-uniform sediment in a seepage-affected alluvial channel

  Publikacja

  • A. Sharma
  • O. Herrera-Granados
  • B. Kumar

  - HYDROLOGICAL SCIENCES JOURNAL-JOURNAL DES SCIENCES HYDROLOGIQUES - Rok 2019

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• Photogrammetric and computerized report on site model in feasibility study of navigability channel on vistula spit

  Publikacja

  • A. Janowski
  • J. Szulwic

  - POLISH JOURNAL OF ENVIRONMENTAL STUDIES - Rok 2008

  In the report the authors present a course of geodesic and geo-computerized works upon realization of feasibility study of navigability channel on Vistula Spit. A procedure of acquiring verification and modeling of data for requirements of a numeric model of a bottom and site has been presented with construction of original software for 3D visualization of the Vistula Spit area. The activities described in the report can be...

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• Relativistic theory of photoionization of one electron systems: an eigen channel R-matrix approach.

  Publikacja

  • M. Gruchowski
  • R. Szmytkowski

  - RADIATION PHYSICS AND CHEMISTRY - Rok 2003

  Przedstawiono zastosowanie metody kanałów własnych R-macierzy do opisu procesu fotojonizacji relatywistycznych układów jednoelektronowych.

• Buckling and initial post-local buckling behaviour of cold-formed channel member flange

  Publikacja

  • C. K. Szymczak
  • M. Kujawa

  - THIN-WALLED STRUCTURES - Rok 2019

  The 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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• Dynamics of Changes in The Urban Space

  Publikacja

  • C. Kowalczyk

  - Rok 2014

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• The Effectiveness of Operations Implementing Changes

  Publikacja

  • J. Łopatowska
  • K. Grzybowska

  - Rok 2011

  W niniejszym rozdziale zdefiniowano pojęcie efektywności zmian organizacyjnych. Scharakteryzowano również składowe elementy efektywności, jakimi są skuteczność, korzystność i ekonomiczność. Pokazano również miejsce oceny efektywności zmian w procesie realizacji przekształceń. Przedstawiono również model oceny efektywności zmian procesu planowania i sterowania umożliwiający ocenę skuteczności, korzystności i ekonomiczności zmian.

• Enviroment of Polish democratisation changes

  Publikacja

  • R. Majewski

  - Rok 2005

  W 1989 r. zapoczątkowany został w krajach Europy Środkowo-Wschodniej proces demokratyzacji. Demokratyzacja oznacza zmianę systemu społecznego w kierunku ideałów i instytucji zakorzenionych w krajach Europy Zachodniej, USA i Kanady opierających się m.in. o zasady: 1. Suwerenności narodu; 2. Republikańskiej formy państwa; 3. Poszanowaniu zasad państwa prawa; 4. Reprezentacji politycznej; 5. Podziału władzy i równoważenia się władz;...

• Management of changes in software engineering

  Publikacja

  • C. Orłowski

  - Rok 2005

  Praca zawiera rozdział poświecony problematyce budowy systemów z bazami wiedzy dla wspomagania procesów zarządzania. W rozdziale tym przedstawiono metody budowy systemów dla potrzeb zarządzania koncentrując uwagę na systemach opartych na wiedzy. Następnie omówiono możliwości zastosowania teorii zbiorów rozmytych do modelowania wiedzy. Na zakończenie przedstawiono przykład wykorzystania zbiorów rozmytych i systemów opartych na wiedzy...

• An Empirical Model for the Polarisation Characteristics of Indoor Off-Body Channels

  Publikacja

  • K. Turbić
  • S. J. Ambroziak
  • L. M. Correia

  - Rok 2017

  This paper presents an analysis of the polarisation characteristics for the channel in dynamic off-body communications, and an empirical channel model, based on measurements performed at 2.45 GHz in an office environment. Body presence and propagation conditions have a strong influence on signal depolarisation. The model assumes three components for the total path loss: mean path loss, represented by a log-distance function with...

• Measurements of Path Loss in Off-Body Channels in Indoor Environments

  Publikacja

  • S. J. Ambroziak
  • M. Maćkowiak
  • R. Katulski
  • J. Sadowski
  • L. M. Correia

  - Rok 2014

  This paper presents a measurements of the path loss for validation of a statistical model for off-body radio channels in an indoor multipath environment, which considers the distance dependent mean path loss, and describes body shadowing and fast fading components in a statistical way. The measurement equipment and propagation indoor environment have been presented. Two different bodies and five static and two walking scenarios...

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• Measurements of Path Loss in Off-Body Channels in Indoor Environments

  Publikacja

  • S. J. Ambroziak
  • L. M. Correia
  • R. Katulski
  • M. Maćkowiak

  - Rok 2015

  The main goal of the paper is to investigate the influence of body orientation and on-body antenna placement on the path loss in off-body communications. In addition, the influence of different bodies is analysed.

• Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks

  Publikacja

  • J. Sadowski

  - International Journal of Antennas and Propagation - Rok 2015

  This paper presents results of investigation on the coherence bandwidth of narrowband radio channels in 430MHz band. The coherence bandwidth values were estimated froma power delay profile obtained by recording CDMA2000 forward channel signals during real-fieldmeasurements in various environments:mediumcity, flat terrain, and hilly terrain in northern Poland.The results of measurements are compared with characteristic parameters...

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• Shading of River Channels as an Important Factor Reducing Macrophyte Biodiversity

  Publikacja

  • S. Jusik
  • R. Staniszewski

  - POLISH JOURNAL OF ENVIRONMENTAL STUDIES - Rok 2019

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• Path Loss Analysis in Off-Body Channels in Indoor Environment

  Publikacja

  • S. J. Ambroziak
  • L. M. Correia
  • R. Katulski
  • M. Maćkowiak

  - Rok 2015

  This temporary document describes an analysis of path loss in off-body channels in an indoor environment. The influence of body orientation and on-body antenna placement on path loss in off-body communications as well as of different bodies has been investigated. Five static scenarios, six distances between body and antenna and eight body orientations were analysed; moreover, two dynamic scenarios were investigated. The smallest...

• Software tools for identification, visualization and analysis of protein tunnels and channels

  Publikacja

  • J. Brezovsky
  • E. Chovancova
  • A. Gora
  • A. Pavelka
  • L. Biedermannova
  • J. Damborsky

  - BIOTECHNOLOGY ADVANCES - Rok 2013

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• Computer-assisted enzyme engineering by modification of tunnels, channels and gates

  Publikacja

  • A. Gora
  • J. Brezovsky
  • J. Damborsky

  - CURRENT OPINION IN BIOTECHNOLOGY - Rok 2011

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• On entaglement distillation and quantum error correction of unknown states and channels.

  Publikacja

  • P. Horodecki

  - CENTRAL EUROPEAN JOURNAL OF PHYSICS - Rok 2003

  Badano niezmienniczości splątania kwantowego oraz pojemności kwantowego kanału ze względu na ewentualną utratę informacji o pojedynczej kopii kwantowego stanu. Pokazano, że jeżeli dany kwantowy kanał ma pewne pojemności niezerowe, to odpowiadające mu stany posiadają niezerowe destylowalne splątanie. Postawiono pewne otwarte problemy dotyczące destylowalności splątania.

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• Methods of Determining Pressure Drop in Internal Channels of a Hydraulic Motor

  Publikacja

  • P. Śliwiński
  • P. Patrosz

  - ENERGIES - Rok 2021

  In this paper, new methods for determining the pressure drop in internal channels of a hydraulic motor are proposed and described. Mathematical models of pressure losses in internal channels have also been described. Experimental tests of the satellite motor were carried out according to one of the proposed methods. The tests were carried out for two liquids, i.e., water and mineral oil. Experimental studies have shown that at...

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• Experimental investigations on adiabatic frictional pressure drops of R134a during flow in 5mm diameter channel

  Publikacja

  • R. Andrzejczyk
  • T. Muszyński
  • C. A. Dorao

  - EXPERIMENTAL THERMAL AND FLUID SCIENCE - Rok 2017

  The article presents detailed two-phase adiabatic pressure drops data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg/m2 s. The frictional pressure drop was characterized for the refrigerant R134a, for vapor qualities ranging from 0 to 1. Long-time thermal stability of test facility allowed to gather...

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• LABORATORY STAND FOR INVESTIGATIONS OF THE QUICK - CHANGING TEMPERATURE OF GAS FLOWING IN THE PISTON COMPRESSOR OUTLET CHANNEL

  Publikacja

  • P. Puzdrowska

  - Journal of Polish CIMEEAC - Rok 2014

  This 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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• FPGA based, DSP board for LLRF 8-Channel SIMCON 3.0 Part I: Hardware

  Publikacja

  • W. Giergusiewicz
  • W. Koprek
  • W. Jalmuzna
  • K. Pozniak
  • R. Romaniuk
  • R. S. Romaniuk

  - Rok 2005

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• Vessel Scheduling Optimization Model Based on Variable Speed in a Seaport with One-Way Navigation Channel

  Publikacja

  • D. Liu
  • G. Shi
  • K. Hirayama

  - SENSORS - Rok 2021

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• A method for testing the wide-sense stationary uncorrelated scattering assumption fulfillment for an underwater acoustic channel

  Publikacja

  • I. Kochańska
  • I. Nissen
  • J. Marszal

  - Journal of the Acoustical Society of America - Rok 2018

  Wide-sense stationary and uncorrelated scattering (WSSUS) assumptions are often applied for the statistical description of wireless communication channels. However, in the case of underwater acoustic channels the WSSUS model is of limited value. The degree of similarity of in-phase and quadrature components of the channel impulse response, measured with the use of bandpass modulated signals, can be used as an indicator of WSSUS...

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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

  Publikacja

  • M. Kalinowski
  • R. Koba
  • P. Jerzyło

  - Bulletin of the Maritime Institute in Gdańsk - Rok 2017

  International 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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• Inhibition of T-type calcium channel disrupts Akt signaling and promotes apoptosis in glioblastoma cells.

  Publikacja

  • N. C. Valerie
  • B. Dziegielewska
  • A. S. Hosing
  • E. Augustin
  • L. S. Gray
  • D. L. Brautigan
  • J. M. Larner
  • J. Dziegielewski

  - BIOCHEMICAL PHARMACOLOGY - Rok 2013

  Glioblastoma multiforme (GBM) are brain tumors that are exceptionally resitant to both radio- and chemotherapy regimens and novel approaches to treatment are needed. T-type calcium channels are one type of low voltage-gated channel (LVCC) involved in embryonic cell proliferation and differentiation; however they are often over-expressed in tumors, including GBM. In this study, we found that inhibition of T-type Ca channels in GBM...

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• Analytical-numerical approach to solve the transport equation for steady gradually varied flow in open channel

  Publikacja

  • R. Szymkiewicz
  • K. Weinerowska-Bords

  - Rok 2005

  W pracy przedstawiono metodę rozwiązania równania transportu adwekcyjno-dyfuzyjnego w przypadku ustalonego niejednostajnego przepływu w kanałach otwartych. Metoda wykorzystuje technikę dekompozycji. Do rozwiązania równania adwekcji-dyfuzji zastosowano analityczne rozwiązanie w postaci odpowiedzi impulsowej liniowego równania adwekcji-dyfuzji. Dokonano adaptacji metody dla przypadku ze zmiennymi parametrami. Do rozwiązania drugiej...

• Linkages between services and manufacturing as a new channel for GVC development: Evidence from CEE countries

  Publikacja

  • A. Kordalska
  • M. Olczyk

  - Structural Change and Economic Dynamics - Rok 2021

  The goal of the paper is to verify a causal relationship between forward linkages from domestic services to manufacturing and the participation/position of a country in global value chains (GVCs) in selected Central and Eastern European economies. We observed a strong polarisation pattern: the Baltic countries along with the Czech Republic strengthen their positions and participation in GVCs by having a strong relationship between...

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• Study of probe signal bandwidth influence on estimation of coherence bandwidth for underwater acoustic communication channel

  Publikacja

  • I. Kochańska
  • J. Schmidt
  • A. Schmidt

  - APPLIED ACOUSTICS - Rok 2021

  A signal transmitted in a shallow Underwater Acoustic Communication (UAC) channel suffers from time dispersion due to the multipath propagation and the refraction phenomena. This causes intersymbol interference of the received signal and frequency-selective fading observed in its spectrum. Coherence bandwidth is one of the key transmission parameters used for designing the physical layer of a data transmission system to minimise...

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• Linkages between services and manufacturing as a new channel for GVC growth: evidence from CEE countries

  Publikacja

  • A. Kordalska
  • M. Olczyk

  - Rok 2018

  The aim of this paper is to use a panel Granger causality test to verify the hypothesis of the existence of a causal relationship between forward linkages from domestic services to manufacturing and a country’s participation and position in GVCs in selected central and eastern European economies – the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland and Slovakia – for the period 2000-2014. Our results show that the Baltic...

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• Selected properties and parameters of radio channel impulse response estimation in ISM 2.4 GHz band

  Publikacja

  • A. Czapiewska
  • R. Studanski,

  - Proceedings of SPIE - Rok 2019

  The article presents experimental research indicating that the impulse response of the communication channel, determined in practice, are not of an universal character, but only represent its approximate value for the frequency on which this measurement was made. Phases for each of the replicas of the measurement signal were determined during the analysis of the received signals in the baseband. Phase changes of individual replicas...

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• Channel Blockage and Flow Maldistribution during Unsteady Flow in a Model Microchannel Plate heat Exchanger

  Publikacja

  • P. Dąbrowski
  • M. Klugmann
  • D. Mikielewicz

  - Journal of Applied Fluid Mechanics - Rok 2019

  This paper describes the problem of channel blockage as a result of flow maldistribution between the channels of a model mini channel plate heat exchanger consisting of one pass on each leg. Each leg of the heat exchanger contains 51 parallel and rectangular minichannels of four hydraulic diameters namely 461 μm, 571 μm, 750 μm and 823 μm. In addition, a more complex geometry has been investigated where for the sake of breaking...

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• Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations

  Publikacja

  • D. Gąsiorowski

  - JOURNAL OF HYDROLOGY - Rok 2013

  The paper concerns the untypical aspect of application of the dissipative numerical methods to solve nonlinear hyperbolic partial differential equations used in open channel hydraulics. It is shown that in some cases the numerical diffusion generated by the applied method of solution produces not only inaccurate solution but as well as a balance error. This error may occur even for an equation written in the conservative form not...

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• Changes in conditions of acoustic wave propagation in the Gdansk deep as an effect of climate changes in the Baltic Sea region

  Publikacja

  • G. Grelowska
  • E. Kozaczka

  - Rok 2020

  The article presents the results from a research project investigating acoustic climate changes in the Gdansk Deepbased on data extending from 1902 to 2019. This part of the southern Gotland Basin, is rarely discussed in thescientific literature.The speed of sound in the seawater is a function of temperature, salinity, and depth. In such shallow sea asBaltic Sea, the impact of depth is not substantial....

• Linking occurrence and changes in local abundance of farmland bird species to landscape composition and land-use changes

  Publikacja

  • Å. Berg
  • J. Wretenberg
  • M. Żmihorski
  • M. Hiron
  • T. Pärt

  - AGRICULTURE ECOSYSTEMS & ENVIRONMENT - Rok 2015

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