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Wyniki wyszukiwania dla: CHANNEL BLOCKAGE
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Channel State Estimation in LTE-Based Heterogenous Networks Using Deep Learning
PublikacjaFollowing 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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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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Adaptive Identification of Underwater Acoustic Channel with a Mix of Static and Time-Varying Parameters
PublikacjaWe 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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Structural Change and Economic Dynamics
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TECHNOLOGICAL FORECASTING AND SOCIAL CHANGE
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Capturing nonexponential dynamics in the presence of two decay channels
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Experimental investigations on condensation in flow in small diameter channels
PublikacjaW 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.
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Underwater Acoustic Communications in Time-Varying Dispersive Channels
PublikacjaUnderwater 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
PublikacjaThe 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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Decoherence-free communication over multiaccess quantum channels
PublikacjaIn 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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Channel View Publications
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Photogrammetric and computerized report on site model in feasibility study of navigability channel on vistula spit
PublikacjaIn 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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Bedload transport and temporal variation of non-uniform sediment in a seepage-affected alluvial channel
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Relativistic theory of photoionization of one electron systems: an eigen channel R-matrix approach.
PublikacjaPrzedstawiono zastosowanie metody kanałów własnych R-macierzy do opisu procesu fotojonizacji relatywistycznych układów jednoelektronowych.
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Local buckling and initial post-buckling behaviour of channel member flange - analytical approach
PublikacjaThe 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...
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Stationary underwater channel experiment: Acoustic measurements and characteristics in the Bornholm area for model validations
PublikacjaThe 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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Multi-channel radio-over-fiber communication systems through modulation instability phenomenon
PublikacjaRecent advancements in Radio-over-Fiber (RoF) technology have positioned it as a promising solution for highcapacity wireless communications. This paper explores novel applications of RoF systems in enhancing phased array antenna (PAA) performance for multi-channel wireless communication applications through the modulation instability (MI) phenomenon. Utilizing fibers experiencing MI with varying group velocity dispersions (β2)...
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Numerical Analysis of Steady Gradually Varied Flow in Open Channel Networks with Hydraulic Structures
PublikacjaIn 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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Buckling and initial post-local buckling behaviour of cold-formed channel member flange
PublikacjaThe 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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Local buckling of compressed flange of cold-formed channel members made of aluminum alloy
PublikacjaThe 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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Dynamics of Changes in The Urban Space
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Enviroment of Polish democratisation changes
PublikacjaW 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;...
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Management of changes in software engineering
PublikacjaPraca 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...
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The Effectiveness of Operations Implementing Changes
PublikacjaW 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.
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Software tools for identification, visualization and analysis of protein tunnels and channels
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Computer-assisted enzyme engineering by modification of tunnels, channels and gates
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Shading of River Channels as an Important Factor Reducing Macrophyte Biodiversity
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On entaglement distillation and quantum error correction of unknown states and channels.
PublikacjaBadano 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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Measurements of Path Loss in Off-Body Channels in Indoor Environments
PublikacjaThis 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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An Empirical Model for the Polarisation Characteristics of Indoor Off-Body Channels
PublikacjaThis 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...
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Path Loss Analysis in Off-Body Channels in Indoor Environment
PublikacjaThis 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...
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Measurement of Coherence Bandwidth in UHF Radio Channels for Narrowband Networks
PublikacjaThis 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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Measurements of Path Loss in Off-Body Channels in Indoor Environments
PublikacjaThe 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.
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Methods of Determining Pressure Drop in Internal Channels of a Hydraulic Motor
PublikacjaIn 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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FPGA based, DSP board for LLRF 8-Channel SIMCON 3.0 Part I: Hardware
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Vessel Scheduling Optimization Model Based on Variable Speed in a Seaport with One-Way Navigation Channel
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Analytical-numerical approach to solve the transport equation for steady gradually varied flow in open channel
PublikacjaW 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...
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LABORATORY STAND FOR INVESTIGATIONS OF THE QUICK - CHANGING TEMPERATURE OF GAS FLOWING IN THE PISTON COMPRESSOR OUTLET CHANNEL
PublikacjaThis 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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Experimental investigations on adiabatic frictional pressure drops of R134a during flow in 5mm diameter channel
PublikacjaThe 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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Balance errors generated by numerical diffusion in the solution of non-linear open channel flow equations
PublikacjaThe 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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A method for testing the wide-sense stationary uncorrelated scattering assumption fulfillment for an underwater acoustic channel
PublikacjaWide-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
PublikacjaInternational 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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Selected properties and parameters of radio channel impulse response estimation in ISM 2.4 GHz band
PublikacjaThe 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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Linkages between services and manufacturing as a new channel for GVC development: Evidence from CEE countries
PublikacjaThe 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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Linkages between services and manufacturing as a new channel for GVC growth: evidence from CEE countries
PublikacjaThe 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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Study of probe signal bandwidth influence on estimation of coherence bandwidth for underwater acoustic communication channel
PublikacjaA 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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Journal of Educational Change
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Journal of Change Management
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Climate Change Economics
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Nature Climate Change
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