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Search results for: CALL DISENGAGEMENT DELAY
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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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Call processing performance in multidomain IMS/NGN architecture
PublicationThe Next Generation Network (NGN) architecture, which bases on the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of the modern information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design and dimensioning are necessary. This also requires appropriate traffic models, which should be efficient and not excessively complicated...
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Simulation model of IMS/NGN call processing performance
PublicationIn current telecommunications it is assumed that demands of the information society for quickly delivered services will be satisfied by the Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As the NGN architecture is very complicated,...
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Simulation model for assessment of IMS-based NGN call processing performance
PublicationIn current telecommunications it is assumed that demands of information society for quickly delivered services will be satisfied by Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As NGN architecture is very complicated, the most...
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Analysis of IMS/NGN call processing performance using G/G/1 queuing systems approximations
PublicationThe paper concerns the Next Generation Network (NGN), which is standardized for distribution of multimedia services based on the IP Multimedia Subsystem (IMS). To guarantee quality, accurate traffic models of IMS/NGN should be proposed. In the paper we compare results obtained with our analytical and simulation model of a single IMS/NGN domain, where various queuing systems are used in the analytical model (M/G/1 and approximations...
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Call Processing Performance in a Multidomain IMS/NGN with Asymmetric Traffic
PublicationIn this paper we continue our research using the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). The aim of the model is to assess mean Call Set-up Delay (CSD) and mean Call Disengagement Delay (CDD), which are standardized call processing performance parameters. The output variables...
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Traffic model for evaluation of call processing performance parameters in IMS-based NGN
PublicationIn the modern world requirements for accurate and fast information distribution are becoming more and more important, which creates a strong necessity for appropriate telecommunication network architecture. Proposition of such an architecture is the Next Generation Network (NGN) concept, which in order to guarantee Quality of Service (QoS), should be correctly designed and dimensioned. For this reason proper traffic models must...
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TRAFFIC MODEL OF A MULTIDOMAIN IMS/NGN
PublicationIn this paper we continue our research and present an analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). The model takes into account several service scenarios (including registration, intra- and inter-operator calls) and a large set of network parameters. Using the model mean Call Set-up Delay and mean Call...
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Analysis of IMS/NGN call processing performance using phase-type distributions
PublicationThis work is a continuation of our research on the traffic model dedicated for design and analysis of the Next Generation Network (NGN), which is standardized for distribution of current and future multimedia services based on the IP Multimedia Subsystem (IMS). Our analytical and simulation models allow evaluation of mean Call Set-up Delay E(CSD) as well as mean Call Disengagement Delay E(CDD) in a single domain of IMS/NGN. Ensuring...
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Analysis of IMS/NGN Call Processing Performance Using Phase-Type Distributions Based on Experimental Histograms
PublicationThe paper describes our further research done with the proposed analytical and simulation traffic models of the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). The aim of our models of a single IMS/NGN domain is to evaluate two standardized call processing performance parameters, which appropriate values are very...
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Verification of the Analytical Traffic Model of a Multidomain IMS/NGN Using the Simulation Model
PublicationIn this paper we verify the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). For this reason a proper simulation model used, in which not theoretical queuing system models but the operation of real network elements and standardized call scenarios are accurately implemented. Consequently,...
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Performance Models of a Multidomain IMS/NGN Service Stratum
PublicationThis paper quantifies call processing performance (CPP) of a multidomain IMS/NGN architecture, which was proposed to deliver current and future telecommunication services with strict quality requirements, independently of the transport network technologies. A realistic simulation model is used as a reference for evaluation of the analytical results, in which vari-ous types of queuing systems are applied to model the opera-tion...
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Simulation Model for Application of the SDN Concept in IMS/NGN Network Transport Stratum
PublicationThe paper presents a simulation model allowing examination of cooperation between two currently used telecommunication networks concepts: IP Multimedia Subsystem/Next Generation Network (IMS/NGN) and Software-Defined Networking (SDN). Application of the SDN architecture elements in IMS/NGN networks will enable unified control and management of transport resources for various transport technologies and equipment manufacturers. However,...
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Analytical Traffic Model for a Multidomain IMS/NGN Network Including Service and Transport Stratum
PublicationThis paper addresses the problem of modelling call processing performance (CPP) in a multidomain Next Generation Network (NGN) architecture including the elements of the IP Multimedia Subsystem (IMS) in service stratum and based on the Multiprotocol Label Switching (MPLS) technology in transport stratum. An analytical traffic model for such an architecture is proposed by integrating the formerly implemented submodels of service...
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Quality Parameters in IMS/NGN Networks
PublicationThe Next Generation Network (NGN) architecture, including elements of the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of current and future information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design is necessary with respect to among others standardized call processing performance parameters, including expected...
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Performance Evaluation of a Multidomain IMS/NGN Network Including Service and Transport Stratum
PublicationThe Next Generation Network (NGN) architecture was proposed for delivering various multimedia services with guaranteed quality. For this reason, the elements of the IP Multimedia Subsystem (IMS) concept (an important part of 4G/5G/6G mobile networks) are used in its service stratum. This paper presents comprehensive research on how the parameters of an IMS/NGN network and traffic sources influence mean Call Set-up Delay (E(CSD))...
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Wydajność przetwarzania żądań usług uwarunkowanych czasowo realizowanych w sieci IMS/NGN
PublicationW rozprawie dokonano przeglądu stanu implementacji koncepcji IMS/NGN, a także modeli systemów obsługi z oczekiwaniem pod kątem zastosowania dla serwerów i łączy w modelu analitycznym wielodomenowej sieci IMS/NGN. Przedstawiono założenia dla tego modelu oraz metodologię obliczeń i analizy wyników: średnich czasów E(CSD) zestawiania i E(CDD) rozłączenia połączenia dla scenariuszy połączeń zakończonych sukcesem. Opisano założenia,...
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The model of end-to-end call setup time calculation for Session Initiation Protocol
PublicationEnd-to-end call setup delay is one of the most important grade of service (GoS) parameters for VoIP networks with Session Initiation Protocol (SIP). A typical subscriber wants to have a connection established as soon as possible. From the operator's perspective call setup time is also crucial because he needs to know how probability of successful packet transmission on SIP links is related to a call setup delay. Then he can make...
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Design of a Multidomain IMS/NGN Service Stratum
PublicationThe paper continues our research concerning the Next Generation Network (NGN), which is standardized for delivering multimedia services with strict quality and includes elements of the IP Multimedia Subsystem (IMS). A design algorithm for a multidomain IMS/NGN service stratum is proposed, which calculates the necessary CSCF servers CPU message processing times and link bandwidths with respect to the given maximum values of mean...
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Wisdom in the context of globalization and civilization
PublicationThe book seeks to answer the question - what is wisdom and how should it be used in everyday life? A model of wisdom is presented in which wisdom describes three attributes: knowledge, qualifications (skills) and inspirations leading to consciously controlled processes of correct assessment of the situation and the correct choice of solution options in the context of the art of living. For each attribute, we can specify a set of...
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Call Control Evaluation in ASON/GMPLS Architecture
PublicationThe Automatically Switched Optical Network (ASON) utilizing Generalized Multi–Protocol Label Switching (GMPLS) protocols named as ASON/GMPLS is one of the propositions of Next Generation Network. The basic assumption of ASON control plane is a separation of call control from connection control. The control plane is divided into call control and connection control components. Presented work regards the problem of call control evaluation...
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Call and Connections Times in ASON/GMPLS Architecture
PublicationIt is assumed that demands of information soci- ety could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded by performance evaluation to guarantee society expectations. Call and connections times are in ASON/GMPLS architecture important for real-time applications. Practical...
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CALL-EJ
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A Nyquist filter of fractional delay
PublicationIn the paper a novel discrete-time FIR fractonal delay specjal filter is investigated. This is a Nyquist filter which, besides the traditional its attribute (interymbol interference (ISI) free property), has the ability to compensate for subsample transmission delay involved, for example, in multipath propagation channel. The performance of the filter is analysed and illustrated.
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Burnout as a State: Random-Intercept Cross-Lagged Relationship Between Exhaustion and Disengagement in a 10-Day Study
PublicationBackground: Burnout has been traditionally seen as a chronic and stable state in response to prolonged stress. However, measures of momentary burnout are not well established, even though the within-person approach suggests that the symptoms of burnout may vary from day to day for the same employee. The aim of this study is to examine the daily inter- and intra-personal variability of the symptoms of burnout and the cross-lagged relationship...
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Functional delay fractional equations
PublicationIn this paper, we discuss functional delay fractional equations. A Banach fixed point theorem is applied to obtain the existence (uniqueness) theorem. We also discuss such problems when a delay argument has a form α(t) = αt, 0 < α < 1, by Rusing the method of successive approximations. Some existence results are also formulated in this case. An example illustrates the main result.
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Dispersive Delay Structures With Asymmetric Arbitrary Group-Delay Response Using Coupled-Resonator Networks With Frequency-Variant Couplings
PublicationThis article reports the design of coupled-resonatorbased microwave dispersive delay structures (DDSs) with arbitrary asymmetric-type group delay response. The design process exploits a coupling matrix representation of the DDS circuit as a network of resonators with frequency-variant couplings (FVCs). The group delay response is shaped using complex transmission zeros (TZs) created by dispersive cross-couplings. We also present an...
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MESOSCALE FUNCTIONS OF GPS SLANT DELAY
PublicationThe paper presents a computer module for GPS slant delay determination using data from COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System) mesoscale non-hydrostatic model of the atmosphere which is run on IA64 Feniks computer cluster in the Department of Civil Engineering and Geodesy of the Military University of Technology. The slant delay is the result of integrating the ray (eikonal) equation for the spatial function...
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Knowledge Management Challenges in Collaborative Design of a Virtual Call Centre
PublicationThis paper presents the analysis of knowledge management issues for an user interface consulting project relevant during the development of a Virtual Call Centre. Experiences gathered by the team of designers and team of usability consultants have been described and evaluated from the knowledge management viewpoint. A concept of a knowledge-based system, potentially supporting usability consulting in subsequent IT projects has...
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Burnout as a State: Random-Intercept Cross-Lagged Relationship Between Exhaustion and Disengagement in a 10-Day Study [Response to Letter]
PublicationWe are writing in response to the Letter to the Editor by Block, Bair, and Carillo regarding our study, which took a multilevel approach to examine cross-lagged and co-existing relationships between exhaustion and disengagement, measured daily for ten consecutive working days using the Oldenburg Burnout Inventory (OLBI). We assessed the job burnout symptoms using only eight items, all of them worded negatively. Following Block,...
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Square root RC Nyquist filter of fractional delay
PublicationIn this paper we propose a discrete-time FIR (finite impulse response) filter which couples the role of square root Nyquist filter with fractional delay filter. This filter enables to substitute for a cascade of square root RC (SRRC) Nyquist filter and fractional delay filter in one device/algorithm. The aim is to compensate for transmission delay in communication system. Statistically defined performances, e.g. BER (bit error...
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efficient fractional delay hilbert transform filter in the farrow structure
PublicationIn this paper the design and application of a Fractional Delay Hilbert Transform Filter (FDHTF) into an adaptive sub-sample delay estimation between two separated sinusoidal signals is considered. The FDHTF incorporates the functions of Hilbertian and variable fractional delay filtering of the incoming signal simultaneously, in one stage. In traditional approach each of these operations was performed separately. Obtained value...
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The effect of current delay angle on tripping of residual current devices
PublicationPower electronics converters applied in domestic or similar installations may utilize current delay (phase) angle control to change the level of transferred power. Due to application of such types of converters, earth fault current in the installation may be strongly distorted. The current distortion level depends on a value of current delay angle. This delay angle also influences the tripping threshold of residual current devices....
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Parameter and delay estimation of linear continuous-time systems
PublicationIn this paper the problem of on-line identification of non-stationary delay systems is considered. Dynamics of supervised industrial processes is described by ordinary differential equations. Discrete-time mechanization of their continuous-time representations is based on dedicated finite-horizon integrating filters. Least-squares and instrumental variable procedures implemented in recursive forms are applied for simultaneous identification...
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JALT CALL Journal
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Parameter and delay estimation of linear continuous-time systems
PublicationIn this paper the problem of on-line identification of non-stationary delay systems is considered. Dynamics of supervised industrial processes is usually described by ordinary differential equations. Discrete-time mechanization of their continuous-time representations is based on dedicated finite-horizon integrating filters. Least-squares and instrumental variable procedures implemented in recursive forms are applied for simultaneous...
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On Sample Rate Conversion Based on Variable Fractional Delay Filters
PublicationThe sample rate conversion algorithm based on variable fractional delay filters is often used if the resampling ratio cannot be expressed as the ratio of small integer numbers or if it is not constant. The main advantage of such solution is that it allows for arbitrary resampling ratios which can even be changed during the resampling process. In this paper a discussion on influence of different approaches to fractional filter...
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On–line Parameter and Delay Estimation of Continuous–Time Dynamic Systems
PublicationThe problem of on-line identification of non-stationary delay systems is considered. The dynamics of supervised industrial processes are usually modeled by ordinary differential equations. Discrete-time mechanizations of continuous-time process models are implemented with the use of dedicated finite-horizon integrating filters. Least-squares and instrumental variable procedures mechanized in recursive forms are applied for simultaneous...
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Liquid circulation in the agitated airlift reactor with the high gas disengagement zone
PublicationPrzedstawiono doświadczalne zależności stopnia zatrzymania gazu i prędkości cyrkulacji cieczy od prędkości przepływu gazu i częstości obrotów mieszadła. Obserwowano wzrost prędkości cyrkulacji cieczy ze wzrostem wysokości strefy napowietrzania. Dla niskich częstości obrotów mieszadła prędkość cyrkulacji cieczy wzrastała wraz ze wzrostem prędkości przepływu gazu, natomiast dla wysokich cząstości obrotów mieszadła prędkość cyrkulacji...
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Usługi Third Party Call Control zrealizowane z wykorzystaniem oprogramowania Open Source
PublicationKoncepcja sieci NGN zakłada otwartość na usługi udostępniane użytkownikom (abonentom). Jej realizacja wymaga ulokowania tej funkcjonalności w zewnętrznych elementach w stosunku do sieci telekomunikacyjnej udostępniającej usługi przenoszenia. Jednym z rozwiązań jest serwer Third Party Call Control (3PCC) w którym można ulokować scenariusze sterowania przebiegiem połączenia. W artykule przedstawiono i omówiono projekt, wykonany w...
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Accuracy of Differential Phase Delay Estimation for GPS Spoofing Detection
PublicationGPS spoofing is an attack based on transmission of false signals to target receivers, in order to force the computation of incorrect time, position or velocity information. It is a threat which is recently considered with continuously growing awareness. There is a need for effective way of GPS spoofing detection. Many groups of methods are proposed in the literature. Spatial processing methods are considered to be robust in a wide...
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Influence of the Delay in Monitor System on the Motor Coordination of Musicians while Performing
PublicationThis paper provides a description and results of measurements of the maximum acceptable value of delay tolerated by a musician, while playing an instrument, that does not cause de-synchronization and discomfort. First, methodology of measurements comprising audio recording and a fast camera is described. Then, themeasurement procedure for acquiring the maximum value of delay conditioning...
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Variable Fractional Delay Filter Design Using a Symmetric Window
PublicationIn this paper a numerically efficient method for designing a nearly optimal variable fractional delay (VFD) filter based on a simple and well-known window method is presented. In the proposed method a single window extracted from the optimal filter with fixed fractional delay (FD) is divided into even and odd part. Subsequently, the odd part is discarded and symmetric even part of the extracted window is used to design a family...
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Variable Ratio Sample Rate Conversion Based on Fractional Delay Filter
PublicationIn this paper a sample rate conversion algorithm which allows for continuously changing resampling ratio has been presented. The proposed implementation is based on a variable fractional delay filter which is implemented by means of a Farrow structure. Coefficients of this structure are computed on the basis of fractional delay filters which are designed using the offset window method. The proposed approach allows us to freely...
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Numerical Method for Stability Testing of Fractional Exponential Delay Systems
PublicationA numerical method for stability testing of fractional exponential systems including delays is presented in this contribution. We propose the numerical test of stability for a very general class of systems with a transfer function, which includes polynomials and exponentials of fractional powers of the Laplace variable s combined with delay terms. Such a system is unstable if any root of its characteristic equation, which usually...
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A complex variable fractional-delay FIR filter structure
PublicationW artykule wprowadzamy strukturę zespolonego filtru o skończonej odpowiedzi impulsowej (ang. finite impulse response - FIR) ze zmiennym opóźnieniem ułamkowym (ang. fractional delay - FD). Strukturę tę otrzymujemy na podstawie przestrajanego filtru FD FIR o współczynnikach rzeczywistych. Stanowi ona połączenie zbioru liniowo-fazowych filtrów FIR o współczynnikach stałych rzeczywistych i dwóch łańcuchów mnożąco-akumulujących, zawierających...
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Comments on “Closed Form Variable Fractional Time Delay Using FFT”
PublicationIn this letter drawbacks of the aforementioned paper are pointed out. The proposed approach is improved with minor modifications of the discrete frequency response. This allows for design of fractional delay filters which are close to optimal and can be efficiently implemented in the frequency domain using the sliding DFT based structure. Alternatively, the derived equivalent closed form formulae for offset windows can be used...
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Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublicationTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
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Two-Rate Based Low-Complexity Variable Fractional-Delay FIR Filter Structures
PublicationThis paper considers two-rate based structures for variable fractional-delay (VFD) finite-length impulse response (FIR) filters. They are single-rate structures but derived through a two-rate approach. The basic structure considered hitherto utilizes a regular half-band (HB) linear-phase filter and the Farrow structure with linear-phase subfilters. Especially for wide-band specifications, this structure is computationally efficient...
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Investigations of the Methods of Time Delay Measurement of Stochastic Signals Using Cross-correlation with the Hilbert Transform
PublicationThe article presents the results of simulation studies of four methods of estimating time delay for random signals using cross-correlation with the Hilbert Transform. Selected models of mutually delayed stochastic signals were used in the simulations, corresponding to the signals obtained from scintillation detectors in radioisotope measurements of liquid-gas two-phase flow. Standard deviations of the values of the individual functions...