About
25
Publications
7,283
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
75
Citations
Introduction
Skills and Expertise
Current institution
Publications
Publications (25)
In this paper, three- and four-parameter least
squares (LS) sine fitting algorithms are investigated. It is pointed
out that the three-parameter fitting is well conditioned in its
standard form, both for short and long records. Then, the
conditioning of the four-parameter fitting (4PF) is investigated.
A scaling factor is derived in order to ensure...
In this paper the effect of roundoff errors on sine wave fitting algorithms is investigated. It is shown that the standard calculation of sine wave parameters may result in unexpectedly large errors, even with floating point number representation. The three-and four-parameter Least Squares, the Maximum Likelihood and the Quantile-Based Estimator me...
In this paper the numerical behavior of different sine wave fitting methods is investigated. In addition to the Three- and Four-Parameter Least Squares Fits, also the Maximum Likelihood and the Quantile Based Estimator methods suffer from similar numerical problems that may disturb the result of the ADC test. Suggestions are given in order to impro...
In this paper sine fitting algorithms are investigated for the purpose of ADC testing. The aim is to decide whether the minimum of the cost function (CF) has been reached. For this, two different types of algorithms, the conventional Levenberg-Marquardt and the genetic-type Differential Evolution methods are investigated in order to compare their o...
Analog-digital converters are inherently nonlinear. Conventional A/D conversion allows no real remedy afterwards. However, an alternative is to increase the available information by observing the transition instants, even with a conventional ADC. Performing the conversion with significant oversampling data points at threshold level crosses can be u...
This paper illustrates a method for measuring the parameters of a sinewave by using information about both the codes and threshold levels in a quantizer. It is shown that by adding knowledge about the threshold levels, the input signal parameters can still be recovered when very coarse quantization is applied in a case when the conventional three-p...
This paper introduces a new estimator of the parameters of a sinewave based on the sequence of its quantized values and on the knowledge of the quantizer transition levels. The estimator performance is evaluated against that of the well-established three-parameter sinefit technique. It is shown that the new estimator provides a significantly higher...
The impact of quantization in Multi-Layer Perceptron (MLP) Artificial Neural Networks (ANNs) is presented in this paper. In this architecture, the constant increase in size and the demand to decrease bit precision are two factors that contribute to the significant enlargement of quantization errors. We introduce an analytical tool that models the p...
A known challenge when building nonlinear models from data is to limit the size of the model in terms of the number of parameters. Especially for complex nonlinear systems, which require a substantial number of state variables, the classical formulation of the nonlinear part (e.g. through a basis expansion) tends to lead to a rapid increase in the...
In this paper, roundoff errors in Artificial Neural Networks (ANNs) are analyzed on a model for Solid-State Power Amplifiers (SSPAs). Calculations are carried out on 32-bit Floating-Point (FP32) arithmetics, and results are verified using 64-bit floating-point representation as reference. Besides the modeling of quan-tization noise at every operati...
Engineers and scientists want mathematical models of the observed system for understanding, design, and control. Many mechanical and civil structures are nonlinear. This paper illustrates a combined nonparametric and parametric system identification framework for modelling a nonlinear vibrating structure. First step of the process is the analysis:...
In this paper, we present an analytical solution to the nonlinear optimization problem encountered in the context of the filtered canonical polyadic decomposition. It is shown that the originally proposed alternating least squares (ALS) approach can be significantly accelerated through a thorough analysis of one of the matrix factors, that is, the...
In this paper, we present an analytical solution to the nonlinear optimization problem encountered in the context of the filtered canonical polyadic decomposition. It is shown that the originally proposed alternating least squares (ALS) approach can be significantly accelerated through a thorough analysis of one of the matrix factors, that is, the...
Engineers and scientists want mathematical models of the observed system for understanding, design and control. Many mechanical and civil structures are nonlinear. This paper illustrates a combined nonparametric and parametric system identification framework for modeling a nonlinear vibrating structure. First step of the process is the analysis: me...
Abstract A computationally efficient four‐parameter least squares (LS) sine fitting method in the time domain is presented here. Unlike the most widespread procedure defined in the relevant IEEE standard, the proposed fitting is non‐iterative. This is achieved by the second‐order approximation of the cost function (CF) around the actual frequency o...
In this paper a frequency domain multiharmonic least squares estimator is presented. The least squares minimization can be slow for long measurement records. It is shown that performing the fit in the frequency domain using Blackman-Harris window function, the number of samples used during the calculations can be reduced significantly. The statisti...
In this paper a frequency domain multiharmonic least squares estimator is presented. The least squares minimization can be slow for long measurement records. It is shown that performing the fit in the frequency domain using Blackman-Harris window function, the number of samples used during the calculations can be reduced significantly. The statisti...
In this paper, a scaling method is proposed and studied for the maximum likelihood sine fitting algorithm. It is shown that similarly to the case of least squares fitting, this method can significantly improve the conditioning of the investigated algorithm. The maximum error in the solution of a linear system of equations strongly depends on the co...
In order to efficiently integrate renewable energy sources - the production of which can be planned harder - in the energy grid, quite accurate forecasts are needed. Especially in Hungary, where energy storage is yet an unsolved problem. The limited ability of wind forecast means that the delivered power of the wind farms cannot be predicted with s...
![Figure 3 Illustration of the amplitude error, Figure after [3] In this...](publication/236894673/figure/fig2/AS:667659129593863@1536193749182/llustration-of-the-amplitude-error-Figure-after-3-In-this-case-the-available_Q320.jpg)
In this paper a novel approach to A/D conversion is introduced. After significant oversampling data points can be selected of which we precisely know the value – these are the samples at threshold crosses. The thresholds are determined beforehand using histogram testing. To have sufficient number of threshold crosses, dither can be added. Finally,...
