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Search results for: non-standard difference methods
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Backscattering properties of southern Baltic herring
PublicationReliable TS(L) relationship is required to improve acoustic algorithms of abundanceestimation of Baltic herring. The relationships, empirically obtained in different parts of theBaltic Sea, produce up to 8 dB – difference in the herring TS. In order to develop an accurateTS(L) relationship, it is important to analyze factors controlling the TS variability. Thepossible impact of the regional difference...
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Broadband Compact Single-Layer Magic-T Junction with Separation of DC Signals between All Ports
PublicationA novel structure for a four-port microstrip magic-T junction is presented. The device is composed of microstrip and slotline circuits etched onto two sides of a dielectric substrate. The device is extremely compact and occupies an area more than three times smaller than similar structures recently reported in the literature. The novelty of the device lies in the use of microstrip/slotline transitions for both input ports: summation...
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Electrohydrodynamic Secondary Flow and Particle Collection Efficiency in a One-sided Spike-plate Type Electrostatic Precipitator
PublicationIn this work, results of electrohydrodynamic secondary flow and particle collection efficiency measurements in an electrostatic precipitator under positive and negative voltage polarity are presented. The electrostatic precipitator had two plate collecting electrodes and a single spike discharge electrode. The spike tips were only on one side of the discharge electrode, therefore called a one-sided spike electrode. The electrohydrodynamic...
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New First - Path Detector for LTE Positioning Reference Signals
PublicationIn today's world, where positioning applications reached a huge popularity and became virtually ubiquitous, there is a strong need for determining a device location as accurately as possible. A particularly important role in positioning play cellular networks, such as Long Term Evolution (LTE). In the LTE Observed Time Difference of Arrival (OTDOA) positioning method, precision of device location estimation depends on accuracy...
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Greencoin: prototype of a mobile application facilitating and evidencing pro-environmental behavior of citizens
PublicationAmong many global challenges, climate change is one of the biggest challenges of our times. While it is one of the most devastating problems humanity has ever faced, one question naturally arises: can individuals make a difference? We believe that everyone can contribute and make a difference to the community and lives of others. However, there is still a lack of effective strategies to promote and facilitate pro-environmental...
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On some open questions for Ramsey and Folkman numbers
PublicationWe discuss some of our favorite open questions about Ramsey numbers and a related problem on edge Folkman numbers. For the classical two-color Ramsey numbers, we first focus on constructive bounds for the difference between consecutive Ramsey numbers. We present the history of progress on the Ramsey number R(5,5) and discuss the conjecture that it is equal to 43.
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Application of method of differential magnetometric system for detection of sunken objects
PublicationThis paper presents a magnetometric system with scalar sensors mounted on two independent platforms, which is used to detect sunken shipwrecks. Increasing the distance between the sensors allows for more precise measurement of the difference in the magnetic induction module than in the case of sensors mounted e.g. on the aeroplane’s wings. This type of system makes it possible to enlarge detection range of the sunken wrecks.
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Using GPUs for Parallel Stencil Computations in Relativistic Hydrodynamic Simulation
PublicationThis paper explores the possibilities of using a GPU for complex 3D finite difference computation. We propose a new approach to this topic using surface memory and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. The case study was performed for the extensive computation of collisions between heavy nuclei in terms of relativistic hydrodynamics.
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Influence of geometrical and operational parameters on tooth wear in the working mechanism of a satellite motor
PublicationThis article describes the phenomena affecting the wear of the rotor of the working mechanism in a hydraulic satellite motor. The basic geometrical relationships that allow the calculation of the coordinates of the points of contact between the satellite and the rotor and the curvature are presented. A method for calculating the number of contacts of the satellite teeth with the rotor teeth and of the satellite teeth with the curvature...
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Frequency based criterion for distinguishing tonal and noisy spectral components
PublicationA frequency-based criterion for distinguishing tonal and noisy spectral components is proposed. For considered spectral local maximum two instantaneous frequency estimates are determined and the difference between them is used in order to verify whether component is noisy or tonal. Since one of the estimators was invented specially for this application its properties are deeply examined. The proposed criterion is applied to the...
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Investigation of long-range dependencies in the stochastic part of daily GPS solutions
PublicationThe long-range dependence (LRD) of the stochastic part of GPS-derived topocentric coordinates change (North, East, Up) results with relatively high autocorrelation values with a focus on self-similarity. One of the reasons for such self-similarity in the GPS time series are noises that are commonly recognised to prevail in the form of the flicker noise model. To prove the self-similarity of the stochastic part of GPS time series...
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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Service time distribution influence on end-to-end call setup delay calculation in networks with Session Initiation Protocol
PublicationThe most important GoS parameter for networks with SIP protocol is end-to-end call setup delay. So far there were no coherent models allowing calculation of these parameters for networks with SIP protocol. Few models were developed but they are insufficient. In the paper we propose model which allows end-to-end call setup delay calculation for networks with SIP protocol. The model is using chain of M/G/1/K models and is applicable...
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Mind the Gender Wage Gap – the Impact of Trade and Competition on Sectoral Wage Difference
PublicationThis article examines differences between women’s and men’s wages in 18 selected OECD countries in the period 1970-2005. The study is based on 12 manufacturing sector- and skill-specific sets of panel data on the gender wage gap. We apply a system GMM estimator to the extended version of the conditional gender wage gap convergence equation, controlling for sector concentration and industry-specific measures of openness using a...
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Study Analysis of Transmission Efficiency in DAB+ Broadcasting System
PublicationDAB+ is a very innovative and universal multimedia broadcasting system. Thanks to its updated multimedia technologies and metadata options, digital radio keeps pace with changing consumer expectations and the impact of media convergence. Broadcasting analog and digital radio services does vary, concerning devices on both transmitting and receiving side, as well as content processing mechanisms. However, the biggest difference is...
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Bio‐polyols synthesized by liquefaction of cellulose: Influence of liquefaction solvent molecular weight
PublicationCurrently, the plastics industry including polyurethanes is based on the use of petrochemicals. For this reason, scientists are looking for new types of renewable resources for the substitution of petrochemical substances. This work aims to evaluate the effect of polyethylene glycols (PEG) with different molecular mass impact on properties of bio-based polyols synthesized via biomass liquefaction of cellulose. To date, research...
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OpenGL accelerated method of the material matrix generation for FDTD simulations
PublicationThis paper presents the accelerated technique of the material matrix generation from CAD models utilized by the finite-difference time-domain (FDTD) simulators. To achieve high performance of these computations, the parallel-processing power of a graphics processing unit was employed with the use of the OpenGL library. The method was integrated with the developed FDTD solver, providing approximately five-fold speedup of the material...
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On the connected and weakly convex domination numbers
PublicationIn this paper we study relations between connected and weakly convex domination numbers. We show that in general the difference between these numbers can be arbitrarily large and we focus on the graphs for which a weakly convex domination number equals a connected domination number. We also study the influence of the edge removing on the weakly convex domination number, in particular we show that a weakly convex domination number...
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Evolution of chemotaxis in single-cell artificial organisms
PublicationThe model of a liquid two-dimensional environment, which is based on physics of diffusion, allows us to simulate the diffusion of morphogenes. Artificial organisms move using a chemotaxis reacting to concentration difference. Organisms are controlled by a gene regulatory network coded in a linear genome and reproduce by division. We made a lot of experiments presenting organisms’ behaviour in various environment conditions. We...
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Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublicationIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
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Detecting coupling directions with transcript mutual information: A comparative study
PublicationCausal relationships are important to understand the dynamics of coupled processes and, moreover, to influence or control the effects by acting on the causes. Among the different approaches to determine cause-effect relationships and, in particular, coupling directions in interacting random or deterministic processes, we focus in this paper on information-theoretic measures. So, we study in the theoretical part the difference between...
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Resonance Frequency Calculation of Spherical Microstrip Structure Using Hybrid Technique
PublicationIn this paper the spherical microstrip structure is considered. The structure is composed of a metallic patch with an arbitrary shape placed on a dielectric coated metallic sphere. In the analysis the hybrid technique is utilized. In this approach the finite-difference technique is applied in a cavity model to determine the current basis functions on the patch. Next, using method of moments, the resonance frequency of the structure...
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Labyrynths generators, their properties and practical application in computer games
Publicationthis paper presents three basic algorithms for generation of mazes, and many of their modifications and examples showing their practical application in creating random structures that resembles those from the real world. the paper highlights the difference in the labyrinths classes generated by listed algorithms and describes a specific and highly likely to occur shapes that occur in generated mazes. particular attention was paid...
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ASYNCHRONICZNY MULTILATERACYJNY SYSTEM DOZOROWANIA OBSZAROWEGO
PublicationW artykule przedstawiono nową metodę lokalizowania samolotów w multilateracyjnych systemach dozorowania obszarowego WAM (Wide Area Multilateration). Metoda ta, nazwana AWAM (Asynchronous Wide Area Multilateration), umożliwia estymację położenia samolotu bez znajomości różnicy w rytmie pracy RTD (Relative Time Difference) pomiędzy stacjami naziemnymi (sensorami). Metoda AWAM znacząco upraszcza proces lokalizowania samolotów w rzeczywistych...
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Towards an efficient multi-stage Riemann solver for nuclear physics simulations
PublicationRelativistic numerical hydrodynamics is an important tool in high energy nuclear science. However, such simulations are extremely demanding in terms of computing power. This paper focuses on improving the speed of solving the Riemann problem with the MUSTA-FORCE algorithm by employing the CUDA parallel programming model. We also propose a new approach to 3D finite difference algorithms, which employ a GPU that uses surface memory....
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Numerical FDM modelling of wave propagation in concrete structure
PublicationThe article presents application of finite difference method to damage detection and its size evaluation in concrete structure by elastic wave propagation method. The simulations of wave propagation in concrete structure were performed for six different damage scenarios. Damages were modelled as areas with changed material properties. Investigation focused on the influence of damage size on the energy of wave reflection. Presented...
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Silent Sonar with matched filtration
PublicationRadars with continuous wave frequency (CW FM sonars) are used in radiolocation as 'silent sonars'. They determine the distance to target by measuring the difference between the frequency of the sounding signal and echo signal. The article presents the principle of operation and parameters of silent CW FM sonars. Target distance determined by these sonars is based on the signal at the output of the matched filter. The Doppler effect...
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ZEUS Concept and Its Wider European Application
PublicationThe objectives of the ZEUS project and the resulting concept of an integrated system of transport safety are recapitulated in the article. The context for transport safety management that has evolved since this became a concern of the European Union under the Treaty of Union in 1993 is outlined, and some issues related to applying the ZEUS concept across Europe are discussed. It is concluded that there is scope for exploring ways...
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On the convergence of a finite-difference discretization à la Mickens of the generalized Burgers–Huxley equation
PublicationIn this note, we establish the property of convergence for a finite-difference discretization of a diffusive partial differential equation with generalized Burgers convective law and generalized Hodgkin–Huxley reaction. The numerical method was previously investigated in the literature and, amongst other features of interest, it is a fast and nonlinear technique that is capable of preserving positivity, boundedness and monotonicity....
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Filtracja danych TDOA w filtrze UKF w systemie multilateracyjnym
PublicationW artykule przedstawiono implementację metody filtracji danych pomiarowych w systemie MLAT(Multilateration), która ma na celu zwiększenie dokładności estymacji położenia poruszającego się statku powietrznego poprzez kompensację błędów pomiarowych. Opisano sposób implementacji algorytmu bezśladowego filtru Kalmana dla danych pomiarowych TDOA (Time Difference of Arrival), a następnie na podstawie zarejestrowanych rzeczywistych tras...
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Estymacja położenia węzłów ruchomych w sieci UWB synchronizowanej emisją z węzła nieruchomego
PublicationW referacie przedstawiono wyniki testów możliwości wykorzystania modemów IR UWB (Impulse Radio Ultra-Wide Band) typu DWM1000 do budowy sieci radiolokalizacyjnej, w której położenie węzłów ruchomych jest estymowane na podstawie pomiarów różnic odległości metodą TDOA (Time Difference of Arrival). Opisana została struktura sieci i sposób synchronizacji pomiarów czasów w nieruchomych węzłach referencyjnych przez cykliczny odbiór sygnałów...
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RESEARCH OF HYDRAULIC PISTON PUMPS’ START-UP IN LOW AMBIENT TEMPERATURES
PublicationStarting hydraulic pumps in low ambient temperatures may cause: decreased hydraulic-mechanical efficiency, larger vibration of hydraulic installation, faster wear and more frequent damage to the elements of pumps, change of material properties of elements, increase of pressure drop. As a result of increase of resistance of cold oil flow in the suction pipe, large underpressure may be experienced, causing incomplete filling of pump...
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Higher responsiveness to rosuvastatin in polygenic versus monogenic hypercholesterolaemia: a propensity score analysis
PublicationBackground The underlying monogenic defect in familial hypercholesterolemia (FH) can be detected in ∼40% of cases. The majority of mutation-negative patients have a polygenic cause of high LDL-cholesterol (LDL-C) due to having inherited a greater than average number of common LDL-C raising single nucleotide polymorphisms (SNPs). Purpose We sought to investigate, whether the monogenic or polygenic defect in FH is associated with...
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Identification of Parameters Influencing the Accuracy of the Solution of the Nonlinear Muskingum Equation
PublicationTwo nonlinear versions of the Muskingum equation are considered. The difference between both equations relates to the exponent parameter. In the first version, commonly used in hydrology, this parameter is considered as free, while in the second version, it takes a value resulting from the kinematic wave theory. Consequently, the first version of the equation is dimensionally inconsistent, whereas the proposed second one is consistent. It...
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Magnetic field microsensor based on GaAs MESFET
PublicationA novel concept of the drain separation design in a horizontally-split-drain GaAs MAGFET sensor, based on epitaxial layer growth, was developed. Proper choice of GaAs/AlAs/GaAs epitaxial layer sequence provided good electrical isolation between the drain regions. The measured leakage current between the drain regions was in the range of nA for up to 2V drain voltage bias difference. Performed analytical and numerical calculations...
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A New Expression for the 3-D Dyadic FDTD-Compatible Green's Function Based on Multidimensional Z-Transform
PublicationIn this letter, a new analytic expression for the time-domain discrete Green's function (DGF) is derived for the 3-D finite-difference time-domain (FDTD) grid. The derivation employs the multidimensional Z-transform and the impulse response of the discretized scalar wave equation (i.e., scalar DGF). The derived DGF expression involves elementary functions only and requires the implementation of a single function in the multiple-precision...
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Impact of radio wave polarisation on off-body communications in indoor environments
PublicationThis paper describes the measurements and the analysis of the impact of radio wave polarisation on off-body communications in Body Area Networks in indoor environments. Measurements on polarisation impact are briefly described. Five investigated scenarios with different body postures and different antenna placements are characterised. The difference between the vertical and horizontal components of the received radio signal are...
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Method of lines for Hamilton-Jacobi functional differential equations.
PublicationInitial boundary value problems for nonlinear first order partial functional differential equations are transformed by discretization in space variables into systems of ordinary functional differential equations. A method of quasi linearization is adopted. Suffcient conditions for the convergence of the method of lines and error estimates for approximate solutions are presented. The proof of the stability of the diffrential difference...
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Modal analysis of a fish-belly flap type of steel water gate
PublicationABSTRACT: The results of a modal analysis of the fish-belly flap type of steel water gate are presented in the paper. The analysis was conducted for a detailed numerical model of the structure using four-node quadrilateral shell elements. The study was focused on the examination of the influence of positioning of the flap gate and hydrostatic pressure of water on the eigenvalues and eigenmodes of the structure. The results of the study...
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High-Resolution, Broad-Range Detection Setup for Polarimetric Optical Fiber Sensors
PublicationA common-path polarization interferometer using a Wollaston prism and an area detector for the measurement of retardation or optical path difference is presented. Employing a moderate-resolution 1280 by 1024 pixel monochrome camera, it offers a measurement range of approximately 780 radians at 830 nm and 1350 radians at 515 nm while maintaining a high measurement resolution. Retardation introduced by a zero-order waveplate or a...
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Experimental analysis of the behaviour of different types of joints in the steel structure model subjected to earthquake loading
PublicationThe present paper reports the results of the experimental study performed to investigate the behaviour of two different types of joints (destroyed and welded ones) in the model of the steel structure under seismic excitations. The structure was subjected to three earthquakes, namely Kobe, Loma Prieta and Northridge, using the shaking table investigation. The results obtained from the study...
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Impact evaluation of a cycling promotion campaign using daily bicycle counters data: The case of Cycling May in Poland
PublicationThe promotion of active and sustainable transport modes as an alternative to motorised individual transport has become a key policy priority in Europe, to reduce air pollution, road congestion, noise, traffic injuries, and the adverse health outcomes of sedentary lifestyles. Policymakers are implementing a wide range of measures to encourage this shift in attitudes and behaviours. These interventions are most valuable when targeting...
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The accuracy of pulse rate estimation from the sequence of face images
PublicationThe goal of this paper is to analyze the accuracy of pulse rate estimation from the sequence of face images. Simulated and real signals were used to evaluate two pulse rate estimators; one for frequency domain and the second one for time domain using the autocorrelation function. The results show that the mean difference between the reference measurements and estimated pulse rate values are about 2bpm. In the analysis of short...
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The influence of combination of binding agents on fatigue properties of deep cold in-place recycled mixtures in Indirect Tensile Fatigue Test (ITFT)
PublicationThe publication presents fatigue properties of cold recycled mixtures for eight combinations of binding agents (cement and bituminous emulsion). Cold recycled mixtures were evaluated in Indirect Tensile Fatigue Test (ITFT) at the temperature of 20 C in controlled stress mode. As a function of horizontal stress, fatigue life is strongly influenced by combination of the binding agents. When fatigue life is analyzed as a function...
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Approximate solution for Euler equations of stratified water via numerical solution of coupled KdV system
PublicationWe consider Euler equations with stratified background state that is valid for internal water waves. The solution of the initial-boundary problem for Boussinesq approximation in the waveguide mode is presented in terms of the stream function. The orthogonal eigenfunctions describe a vertical shape of the internal wave modes and satisfy a Sturm-Liouville problem. The horizontal profile is defined by a coupled KdV system which is...
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Exact modal absorbing boundary condition for waveguide simulations - discrete Green's function approach
PublicationA modal absorbing boundary condition (ABC) based on the discrete Green's function (DGF) is introduced and applied for termination of waveguides simulated by means of the finite-difference time-domain (FDTD) method. The differences between the developed approach and implementations already demonstrated in the literature are presented. By applying DGF, a consistent theoretical approach to modal ABC in the FDTD method is obtained....
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ASYNCHRONICZNA METODA TDOA
PublicationPrzedstawiono nową metodę lokalizowania terminali ruchomych MT (Mobile Terminal) w sieciach radiowych, w których stacje bazowe BS (Base Station) pracują asynchronicznie względem siebie. Metoda ta, nazwana ATDOA (Asynchronous Time Difference of Arrival), umożliwia estymację położenia MT na podstawie pomiarów różnicy czasów propagacji sygnałów radiowych pomiędzy terminalem ruchomym będącym w ruchu, a pojedynczą stacją bazową w różnych...
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Improvement of time difference of arrival measurements resolution by using fractional delay filters in a direct sequence-code division multiple access radionavigation system
PublicationThis study presents a method of improving time measurements resolution in a direct sequence-code division multiple access receiver by using a fine code tracking loop based on fractional delay filtering of a despreading sequence. It briefly describes the structure of a generic digital code tracking loop and the proposed modification which allows to measure time difference of arrival values with the subsample resolution, together...
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Numerical simulation of hardening of concrete plate
PublicationThe paper presents a theoretical formulation of concrete curing in order to predict temperature evolution and strength development. The model of heat flow is based on a well-known Fourier equation. The numerical solution is implemented by means of the Finite Difference Method. In order to verify the model, the in situ temperature measurements at the top plate of a road bridge were carried out. A high agreement between numerical...
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GPU based implementation of Temperature-Vegetation Dryness Index for AVHRR3 Satellite Data
PublicationPaper presents an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland. All phases of TVDI implementation on GPU are modified in respect to CUDA platform....