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Tytuł:
Elementary exposition of Gauss’ final justification of least squares
Autorzy:
Sheynin, Oscar
Powiązania:
https://bibliotekanauki.pl/articles/434120.pdf
Data publikacji:
2014
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
the principle of least squares
the method of least squares
Opis:
Legendre was the first to publish the principle of least squares in 1805, this principle was known to Gauss since 1795. But it was Gauss who introduced the method of least squares. He offered its final justification based on the principle of maximum weight (minimal variance) in 1823 and 1828. I begin with a few words about Legendre and Laplace and continue with describing Gauss’ final justification of least squares. It is extremely complicated, but modern authors removed this difficulty. My own exposition (§ 3) is quite elementary and, I think, methodically necessary.
Źródło:
Śląski Przegląd Statystyczny; 2014, 12(18); 39-47
1644-6739
Pojawia się w:
Śląski Przegląd Statystyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An alternative approach to characterize the commutativity of orthogonal projectors
Autorzy:
Baksalary, Oskar
Trenkler, Götz
Powiązania:
https://bibliotekanauki.pl/articles/729960.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
partitioned matrix
canonical correlations
ordinary least squares estimator
generalized least squares estimator
best linear unbiased estimator
Opis:
In an invited paper, Baksalary [Algebraic characterizations and statistical implications of the commutativity of orthogonal projectors. In: T. Pukkila, S. Puntanen (Eds.), Proceedings of the Second International Tampere Conference in Statistics, University of Tampere, Tampere, Finland, [2], pp. 113-142] presented 45 necessary and sufficient conditions for the commutativity of a pair of orthogonal projectors. Basing on these results, he discussed therein also statistical aspects of the commutativity with reference to problems concerned with canonical correlations and with comparisons between estimators and between sets of linearly sufficient statistics corresponding to different linear models. In the present paper, parts of this analysis are resumed in order to shed some additional light on the problem of commutativity. The approach utilized is different than the one used by Baksalary, and is based on representations of projectors in terms of partitioned matrices. The usefulness of such representations is demonstrated by reinvestigating some of Baksalary's statistical considerations.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2008, 28, 1; 113-137
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The recursive least squares estimation of parametric functions in the general linear model
Rekurencyjna estymacja funkcji parametrycznych metodą najmniejszych kwadratów
Autorzy:
Pordzik, Paweł R
Powiązania:
https://bibliotekanauki.pl/articles/905622.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
least squares estimation of parametric functions
Opis:
W pracy uogólniora zostala technika rekurencyjnej estymacji funkcji parametrycznych metodą najmniejszych kwadratów w ogólnym modelu liniowym. Proponowana procedura umożliwia aktualizację estymatorów zarówno ze względu na dodatkową stochastyczną, jak i niestochastyczną informację o parametrach modelu.
The technique of recursive least squares estimation for the standard regression model is extended lo the general linear model with possibly singular dispersion matrix of error term. It is shown how to update the minimum dispersion linear unbiased estimate of a given vector of parametric functions with respcct to additional sample data which are to be successively incorporated to the inference base.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2002, 156
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A versatile tool for extraction of MOSFETs parameters
Autorzy:
Tomaszewski, D.
Kociubiński, A.
Marczewski, J.
Kucharski, K.
Domański, K.
Grabiec, P.
Powiązania:
https://bibliotekanauki.pl/articles/308856.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
MOSFETs parameters
SPICE
least squares method
Opis:
Extraction of MOSFET parameters is a very important task for the purposes of MOS integrated circuits characterization and design. A versatile tool for the MOSFET parameter extraction has been developed in the Institute of Electron Technology (IET). It is used to monitor the technologies applied for fabrication of several groups of devices, e.g., CMOS ASICs, SOI pixel detectors. At present two SPICE MOSFET models (LEVEL = 1, 2) have been implemented in the extraction tool. The LEVEL = 3 model is currently being implemented. The tool combines different methods of parameter extraction based on local as well as global fitting of models to experimental data.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 1; 129-134
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kriging and masurement errors
Autorzy:
Fazekas, István
Kukush, Alexander
Powiązania:
https://bibliotekanauki.pl/articles/729708.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
universal kriging
least squares
errors-in-variables
Opis:
A linear geostatistical model is considered. Properties of a universal kriging are studied when the locations of observations aremeasured with errors. Alternative prediction procedures are introduced and their least squares errors are analyzed.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2005, 25, 2; 139-159
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A note on the strong consistency of least squares estimates
Autorzy:
da Silva, Joǎo
Powiązania:
https://bibliotekanauki.pl/articles/729980.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
least squares estimates
linear models
strong consistency
Opis:
The strong consistency of least squares estimates in multiples regression models with i.i.d. errors is obtained under assumptions on the design matrix and moment restrictions on the errors.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2009, 29, 2; 223-231
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generating quasigroups for cryptographic applications
Autorzy:
Kościelny, Cz.
Powiązania:
https://bibliotekanauki.pl/articles/908515.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
informatyka
quasigroups
latin squares
stream ciphers
cryptography
Opis:
A method of generating a practically unlimited number of quasigroups of a (theoretically) arbitrary order using the computer algebra system Maple 7 is presented. This problem is crucial to cryptography and its solution permits to implement practical quasigroup-based endomorphic cryptosystems. The order of a quasigroup usually equals the number of characters of the alphabet used for recording both the plaintext and the ciphertext. From the practical viewpoint, the most important quasigroups are of order 256, suitable for a fast software encryption of messages written down in the universal ASCII code. That is exactly what this paper provides: fast and easy ways of generating quasigroups of order up to 256 and a little more.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2002, 12, 4; 559-569
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mixed integer nonlinear programming formulation for the problem of fitting positive exponential sums to empirical data
Autorzy:
Alvarez, A.
Lara, H.
Powiązania:
https://bibliotekanauki.pl/articles/254845.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
mixed integer nonlinear programming
regularization
nonlinear least squares
Opis:
In this work we deal with exponential sum models coming from data acquisition in the empirical sciences. We present a two step approach based on Tikhonov regularization and combinatorial optimization, to obtain stable parameter estimations, which fit the data. We develop properties of the solutions, based on their optimality conditions. Some numerical experiments are shown to illustrate our approach.
Źródło:
Opuscula Mathematica; 2011, 31, 4; 481-499
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Partial Regression Methods to Long Range Forecasts
Autorzy:
Konca-Kędzierska, K.
Powiązania:
https://bibliotekanauki.pl/articles/163875.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwa Geofizyczne
Tematy:
long range forecasts
regression model
partial least squares
Opis:
The article presents the construction of a regression model for the long-range forecast of tercile categories of the monthly mean temperature. Two methods from the group of the partial least squares (PLS) and sparse partial least squares (SPLS) methods were used. The selected methods combine the properties of principal component analysis (PCA) with features of multiple regression methods, and apply the creation of latent layers. These methods also have no restrictions related to the independence of predictors and no constraints on the model dimension. The predictors are percentiles (10%, 50% and 90%) for selected fields of the NCEP/NCAR Reanalysis dataset. The model uses a time series of predictors for periods from 5 to 30 years. The obtained set of forecasts is subjected to the evaluation process based on indicators for the dependent period. This allows for the selection of a reliable ensemble of forecasts. The presented model was tested between January 2014 and December 2016.
Źródło:
Przegląd Geofizyczny; 2018, 4; 353-362
0033-2135
Pojawia się w:
Przegląd Geofizyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Real Time PC Implementation of Power Quality Monitoring System Based on Multiharmonic Least-Squares Fitting
Autorzy:
Ardeleanu, A. S.
Ramos, P. M.
Powiązania:
https://bibliotekanauki.pl/articles/220586.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power quality
real time
multiharmonic least-squares fitting
Opis:
In this paper, an algorithm that monitors the power system to detect and classify power quality events in real time is presented. The algorithm is able to detect events caused by waveform distortions and variations of the RMS values of the voltage. Detection of the RMS events is done by comparing the RMS values with certain thresholds, while detection of waveform distortions is made using an algorithm based on multiharmonic leasts-squares fitting.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 543-554
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sufficient conditions for the strong consistency of least squares estimator with α-stable errors
Autorzy:
Mexia, João
da Silva, João
Powiązania:
https://bibliotekanauki.pl/articles/729990.pdf
Data publikacji:
2007
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
linear models
least squares estimator
strong consistency
stability
Opis:
Let $Y_{i} = x_{i}^{T}β + e_{i}$, 1 ≤ i ≤ n, n ≥ 1 be a linear regression model and suppose that the random errors e₁, e₂, ... are independent and α-stable. In this paper, we obtain sufficient conditions for the strong consistency of the least squares estimator β̃ of β under additional assumptions on the non-random sequence x₁, x₂,... of real vectors.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2007, 27, 1-2; 27-45
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Consistency of trigonometric and polynomial regression estimators
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1339065.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
consistent estimator
orthonormal system
least squares method
regression
Opis:
The problem of nonparametric regression function estimation is considered using the complete orthonormal system of trigonometric functions or Legendre polynomials $e_k$, k=0,1,..., for the observation model $y_i = f(x_i) + η_i $, i=1,...,n, where the $η_i$ are independent random variables with zero mean value and finite variance, and the observation points $x_i\in[a,b]$, i=1,...,n, form a random sample from a distribution with density $ϱ\in L^1[a,b]$. Sufficient and necessary conditions are obtained for consistency in the sense of the errors $\Vert f-\widehat f_N\Vert, \vert f(x)-\widehatf_N(x)\vert$, $x\in[a,b]$, and $E\Vert f-\widehatf_N\Vert^2$ of the projection estimator $\widehat f_N(x) = \sum_{k=0}^N\widehat{c}_ke_k(x)$ for $\widehat{c}_0,\widehat{c}_1,\ldots,\widehat{c}_N$ determined by the least squares method and $f\in L^2[a,b]$.
Źródło:
Applicationes Mathematicae; 1998-1999, 25, 1; 73-83
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On least squares estimation of Fourier coefficients and of the regression function
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1340683.pdf
Data publikacji:
1993
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Fourier series
consistent estimator
least squares method
regression
Opis:
The problem of nonparametric function fitting with the observation model $y_i = f(x_i) + η_i$, i=1,...,n, is considered, where $η_i$ are independent random variables with zero mean value and finite variance, and $x_i \in [a,b] \subset \R^1$, i=1,...,n, form a random sample from a distribution with density $ϱ \in L^1[a,b]$ and are independent of the errors $η_i$, i=1,...,n. The asymptotic properties of the estimator $\widehat{f}_{N(n)}(x) = \sum_{k=1}^{N(n)} \widehat{c}_ke_k(x)$ for $f \in L^2[a,b]$ and $\widehat{c}^{N(n)}=( \widehat{c}_1,..., \widehat{c}_{N(n)})^T$ obtained by the least squares method as well as the limits in probability of the estimators $\widehat{c}_k$, k=1,...,N, for fixed N, are studied in the case when the functions $e_k$, k=1,2,..., forming a complete orthonormal system in $L^2\[a,b\]$ are analytic.
Źródło:
Applicationes Mathematicae; 1993-1995, 22, 1; 91-102
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three mathematical papers of Adam Adamandy Kochański -- annotated English translation
Autorzy:
Fukś, Henryk
Powiązania:
https://bibliotekanauki.pl/articles/749656.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
rectification of a circle, magic squares, Adam Kochański
Opis:
Praca zawiera tłumaczenia z łaciny na język angielski trzech najważniejszych prac matematycznych Adama Adamandego Kochańskiego (1631-1700), wraz z oryginalną wersja łacińską, z przypisami i wprowadzeniem. Prace były opublikowane w Acta Eruditorum w r. 1682 („Solutio theorematum”) , 1685 („Observationes cyclometricae”), oraz 1686 („Considerationes quaedam”). Tłumaczenie jest tak wierne jak to możliwe, często dosłowne. Zamiarem tłumacza było uczynienie go pomocnym dla tych, którzy zechcą zapoznać się z oryginalnym tekstem łacińskim. Prace zostały opatrzone licznymi przypisami zawierającymi informację o nazwiskach i terminach, które mogą nie być znane współczesnemu czytelnikowi. Błędy w druku, obecne w oryginalnym wydaniu, zostały zaznaczone, a poprawki podano w przypisach. Aby ułatwić zrozumienie dowodów zawartych w pracy „Solutio theorematum”, uzupełniono ją dodatkiem zawierającym cytowania z „Elementów” w wersji łacińskiej, używanej przez Kochańskiego.
The paper includes English translations (together with original Latin versions) of three papers of Adam Adamandy Kochański (1631-1700), originally published in Acta Eruditorum in 1682 (“Solutio theorematum”), 1685 (“Observationes cyclometricae”), and 1686 (“Considerationes quaedam”). The translation is as faithful as possible, often literal, and it is mainly intended to be of help to those who wish to study the original Latin text. The papers have been annotated in a number of places, giving more information about names, places and terms which may not be familiar to the contemporary reader. Misprints present in the original edition are indicated, with corrections included in footnotes. A brief introduction oulining the contect of the papers is included. “Solutio theorematum” is followed by an appendix containing all quotes from “Elements” necessary to understand proofs given by Kochański.
Źródło:
Antiquitates Mathematicae; 2015, 9
1898-5203
2353-8813
Pojawia się w:
Antiquitates Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the density and cumulative distribution functions of the exponentiated Burr XII distribution
Autorzy:
Hassan, Amal S.
Assar, Salwa M.
Ali, Kareem A.
Nagy, Heba F.
Powiązania:
https://bibliotekanauki.pl/articles/1917020.pdf
Data publikacji:
2021-12-08
Wydawca:
Główny Urząd Statystyczny
Tematy:
exponentiated Burr Type XII model
least squares estimator
maximum likelihood estimator
uniform minimum variance unbiased estimator
weighted least squares estimator
Opis:
The exponentiated Burr Type XII (EBXII) distribution has wide applications in reliability and economic studies. In this article, the estimation of the probability density function and the cumulative distribution function of EBXII distribution is considered. We examine the maximum likelihood estimator, the uniformly minimum variance unbiased estimator, the least squares estimator, the weighted least squares estimator, the maximum product spacing estimator, the Cramér–von-Mises estimator, and the Anderson–Darling estimator. We derive analytical forms for the bias and mean square error. A simulation study is performed to investigate the consistency of the suggested methods of estimation. Data relating to the wind speed and service times of aircraft windshields are used with the studied methods. The simulation studies and real data applications have revealed that the maximum likelihood estimator performs more efficiently than its remaining counterparts.
Źródło:
Statistics in Transition new series; 2021, 22, 4; 171-189
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stretching the Least Squares to Embed Loss Function Tables
Autorzy:
Yoneda, K.
Moretti, A. C.
Poker, J. Jr.
Powiązania:
https://bibliotekanauki.pl/articles/375983.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
least squares
individual behavior
inverse problems
simultaneous equations
optimization
Opis:
The method of least squares is extended to accommodate a class of loss functions specified in the form of function tables. The function tables are embedded into the standard quadratic loss function so that nonlinear least squares algorithms can be adopted for loss minimization. This is an alternative to a more straightforward approach which interpolates the function tables and minimizes the resulting loss function by some generic optimization algorithm. The alternative approach has advantages over the straightforward, such as the wider availability of the least squares programs compared to the generic optimization programs and reduction in computational complexity. Examples are given for its application to multiplicative utility function maximization problems.
Źródło:
Decision Making in Manufacturing and Services; 2015, 9, 2; 105-116
1896-8325
2300-7087
Pojawia się w:
Decision Making in Manufacturing and Services
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non - invasive identification of servo drive parameters
Autorzy:
Neugebauer, R.
Hellmich, A.
Hofmann, S.
Schlegel, H.
Powiązania:
https://bibliotekanauki.pl/articles/384413.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
identification
parametric model
natural excitation
least squares method
SIMOTION
Opis:
For the tuning of servo controllers as well as for monitoring functions, significant parameters of the controlled system are required. In contrast to identification methods with determined input signals, the paper focuses on the problem of identification with regular process movements (non-invasive identification), leading to a lack of power density in some frequency ranges. A nonlinear Least Squares (LS) approach with single mass system and friction characteristic is investigated regarding the accomplishable accuracy and necessary constraints. The proposed method is applicable on industrial motion controllers and has been carried out with a multitude of input sequences. To verify the performance of the approach, achieved experimental results for the model parameters are exposed.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2012, 6, 2; 13-16
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Islam i magia w kulturze Hausa
Islam and Magic in Hausa Culture
Autorzy:
Siwierska, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/522858.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warszawski. Katedra Języków i Kultur Afryki. Polskie Towarzystwo Afrykanistyczne
Tematy:
magic in Islam,
Hausa
tsibbu
sha rubutu
magical squares
Opis:
The aim of this paper is to examine religious and magical customs widely spread in Northern Nigeria. The most popular is the practice of sha rubutu (literally, the drinking of the written) which is also found in other Islamic countries. It can be regarded as an essential part of the magical corpus of Islam. Both sha rubutu and other magical occupations like the production of charms or protective medicine are based on the belief that some verses and chapters of the Koran are especially powerful and can cure illness, as well as heal injuries.
Źródło:
Afryka; 2016, 44; 85-108
1234-0278
Pojawia się w:
Afryka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of the generalized nonlinear least squares method applied for fitting distribution to data
Autorzy:
Benšić, Mirta
Powiązania:
https://bibliotekanauki.pl/articles/729766.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
generalized least squares
distribution fitting
generalized method of moments
Opis:
We introduce and analyze a class of estimators for distribution parameters based on the relationship between the distribution function and the empirical distribution function. This class includes the nonlinear least squares estimator and the weighted nonlinear least squares estimator which has been used in parameter estimation for lifetime data (see e.g. [6, 8]) as well as the generalized nonlinear least squares estimator proposed in [3]. Sufficient conditions for consistency and asymptotic normality are given. Capability and limitations are illustrated by simulations.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2015, 35, 1-2; 75-94
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the NO2 concentration prediction possibility based on static and dynamic responses of TGS sensors at changing humidity levels
Autorzy:
Kalinowski, Paweł
Woźniak, Łukasz
Jasiński, Grzegorz
Jasiński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/220989.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
TGS sensors
partial least squares
nitrogen dioxide
dynamic measurements
Opis:
The commercially available metal-oxide TGS sensors are widely used in many applications due to the fact that they are inexpensive and considered to be reliable. However, they are partially selective and their responses are influenced by various factors, e.g. temperature or humidity level. Therefore, it is important to design a proper analysis system of the sensor responses. In this paper, the results of examinations of eight commercial TGS sensors combined in an array and measured over a period of a few months for the purpose of prediction of nitrogen dioxide concentration are presented. The measurements were performed at different relative humidity levels. PLS regression was employed as a method of quantitative analysis of the obtained sensor responses. The results of NO2 concentration prediction based on static and dynamic responses of sensors are compared. It is demonstrated that it is possible to predict the nitrogen dioxide concentration despite the influence of humidity.
Źródło:
Metrology and Measurement Systems; 2020, 27, 1; 167-179
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Medium- and long-term prediction of polar motion using weighted least squares extrapolation and vector autoregressive modeling
Autorzy:
Lei, Yu
Zhao, Danning
Guo, Min
Powiązania:
https://bibliotekanauki.pl/articles/27314482.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Centrum Badań Kosmicznych PAN
Tematy:
polar motion
prediction model
weighted least squares
vector autoregressive
Opis:
This article presents the application of weighted least squares (WLS) extrapolation and vector autoregressive (VAR) modeling in polar motion prediction. A piecewise weighting function is developed for the least squares (LS) adjustment in consideration of the effect of intervals between observation and prediction epochs on WLS extrapolation. Furthermore, the VAR technique is used to simultaneously model and predict the residuals of xp, yp pole coordinates for WLS misfit. The simultaneous predictions of xp, yp pole coordinates are subsequently computed by the combination of WLS extrapolation of harmonic models for the linear trend, Chandler and annual wobbles, and VAR stochastic prediction of the residuals (WLS+VAR). The 365-day-ahead xp, yp predictions are compared with those generated by LS extrapolation+univariate AR prediction and LS extrapolation+VAR modeling. It is shown that the xp, yp predictions based on WLS+VAR taking into consideration both the interval effect and correlation between xp and yp outperform those generated by two others. The accuracies of the xp predictions are 13.97 mas, 18.47 mas, and 20.52 mas, respectively for the 150-, 270-, and 365-day horizon in terms of the mean absolute error statistics, 36%, 24.8%, and 33.5% higher than LS+AR, respectively. For the yp predictions, the 150-, 270-, and 365-day accuracies are 15.41 mas, 21.17 mas, and 21.82 mas respectively, 27.4%, 11.9%, and 21.8% higher than LS+AR respectively. Moreover, the absolute differences of the WLS+VAR predictions and observations are smaller than the differences from LS+VAR and LS+AR, which is practically important to practical and scientific users, although the improvement in accuracies is no more than 10% relative to LS+VAR. The further comparison with the predictions submitted to the 1st Earth Orientation Parameters Prediction Comparison Campaign (1st EOP PCC) shows that while the accuracy of the predictions within 30 days is comparable with that by the most accurate prediction techniques including neural networks and LS+AR participating in the campaign for xp, yp pole coordinates, the accuracy of the predictions up to 365 days into the future are better than accuracies by the other techniques except best LS+AR used in the EOP PCC. It is therefore concluded that the medium- and long-term prediction accuracy of polar motion can be improved by modeling xp, yp pole coordinates together.
Źródło:
Artificial Satellites. Journal of Planetary Geodesy; 2023, 58, 2; 42--55
2083-6104
Pojawia się w:
Artificial Satellites. Journal of Planetary Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Moore-Penrose’s inverse and solutions of linear systems
Autorzy:
López-Bonilla, J.
López-Vázquez, R.
Vidal-Beltrán, S.
Powiązania:
https://bibliotekanauki.pl/articles/1177742.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Least squares technique
Linear systems
Pseudoinverse of Moore-Penrose
SVD
Opis:
We employ the generalized inverse matrix of Moore-Penrose to study the existence and uniqueness of the solutions for over- and under-determined linear systems, in harmony with the least squares method.
Źródło:
World Scientific News; 2018, 101; 246-252
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Least squares method modification applied to the NASGRO equation
Modyfikacja metody najmniejszych kwadratów w zastosowaniu do równania NASGRO
Autorzy:
Kłysz, S.
Lisiecki, J.
Leski, A.
Bąkowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/280631.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fatigue crack propagation
NASGRO equation
method of least squares (LSM)
Opis:
The paper has been intended to present some modification of Least Squares Method (LSM) as used for describing of experimentally gained fatigue crack propagation data by means of the NASGRO equation. In particular, the specific nature of the NASGRO equation and consequent difficulties with theoretical description of test data have been shown. An algorithm has been presented of how to find coefficients of the NASGRO equation for the modified LSM criterion. Computations have been performed for the aluminum alloy 2024 taken from the rotor blades of Mi-8 helicopter.
W pracy zaprezentowano modyfikacje Metody Najmniejszych Kwadratów (MNK) w zastosowaniu do opisu przy pomocy równania NASGRO danych doświadczalnych propagacji pęknięć zmęczeniowych. W szczególności wskazano na szczególną postać równania NASGRO i wynikające z tego trudności w teoretycznym opisie wyników badań doświadczalnych. Przedstawiono algorytm do wyznaczania współczynników tego równania przy zmodyfikowanym kryterium MNK. Obliczenia przeprowadzono dla stopu aluminium 2024 pobranego z łopat wirnika śmigłowca Mi-8.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 1; 3-13
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of least-squares method for approximating the surfaces of engineering structures
Zastosowanie metody najmniejszych kwadratów do aproksymacji powierzchni obiektów inżynierskich
Autorzy:
Lenda, G.
Powiązania:
https://bibliotekanauki.pl/articles/385328.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
metoda najmniejszych kwadratów
wpasowywanie powierzchni
least squares method
surface fitting
Opis:
The report is focused on the presentation of current methods allowing for the approximation of point sets by means of ideal mathematical surfaces, as well as on the analysis of their suitability depending on the type of the object approximated and the complexity of the methods. The advantages and disadvantages of these methods have been compared with the capabilities offered by splines. Also, the application of the various variants of LSM have been discussed with reference to the minimization of the algebraic distance, the distance directed along a specific axis of the coordinate system and the geometrical distance. Finally, cases where the application of particular methods is justified with respect to accuracy and cost-effectiveness have been analyzed.
Opracowanie skupia się na przedstawieniu aktualnych metod pozwalających na aproksymację zbiorów punktowych za pomocą idealnych powierzchni matematycznych, jak również na analizie ich przydatności, w zależności od rodzaju przybliżanego obiektu i skomplikowania metody. Zestawiono wady i zalety tych metod z możliwościami, które oferują funkcje sklejane. Następnie przybliżono zastosowanie różnych wariantów metody najmniejszych kwadratów w odniesieniu do minimalizacji odległości algebraicznej, odległości ukierunkowanej wzdłuż konkretnej osi układu współrzędnych oraz odległości geometrycznej. Przeanalizowano również, w jakich przypadkach zastosowanie poszczególnych metod ma uzasadnienie dokładnościowe i ekonomiczne.
Źródło:
Geomatics and Environmental Engineering; 2008, 2, 1; 49-57
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The general form of the elastic stress and displacement fields of the finite cracked plate
Autorzy:
Seif, A. E.
Kabir, M. Z.
Powiązania:
https://bibliotekanauki.pl/articles/949141.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
finite cracked plate
least-squares curve fitting
general series form
Opis:
In this paper, the general forms of in-plane fields of a finite cracked plate have been achieved in the elastic range by expanding the potential functions of the infinite cracked plate about the crack tip. Subsequently, the stress intensity at the crack tip has been obtained. In addition, the numerical models have been provided by the finite element method.The effect of finite sizes on the stress and displacement fields has been detected and to validate the obtained analytical relations, the least-squares curve fitting has been used. Moreover, the calculated stress intensity correction factors have been compared with the existing results in the literature.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1271-1283
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modification of the LSM criteria to approximate test data for fatigue crack growth rate
Modyfikacja kryterium Metody Najmniejszych Kwadratów do aproksymacji wyników badań prędkości propagacji pęknięć zmęczeniowych
Autorzy:
Kłysz, S.
Lisiecki, J.
Leski, A.
Bąkowski, T.
Powiązania:
https://bibliotekanauki.pl/articles/281690.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fatigue crack propagation
NASGRO equation
method of least squares (LSM)
Opis:
Modification of the least squares method criteria is presented. It is intended to enhance the approximation of test data for fatigue crack growth rate. In particular, changes are introduced to improve approximation in the cases when the range of values for at least one of the variables is within the range of several orders of magnitude or differs from the range of values for other variables. Differences between particular criteria and their influence on the approximation of test data is illustrated further on. Calculations are conducted for aluminum alloy 2024 taken from Mi-2 helicopter rotor blades.
W pracy przedstawiono modyfikację kryterium Metody Najmniejszych Kwadratów do poprawienia dokładności aproksymacji wyników badań prędkości propagacji pęknięć zmęczeniowych. W szczególności wprowadzono zmiany do poprawy aproksymacji w przypadku, gdy przedział wartości przynajmniej jednej ze zmiennych jest w zakresie kilku rzędów wielkości lub różni się znacznie od zakresu zmienności drugiej zmiennej. Przedstawiono również różnice pomiędzy poszczególnymi kryteriami i ich wpływ na aproksymację wyników z badań. Obliczenia przeprowadzono dla danych uzyskanych z badań próbek ze stopu aluminium 2024 pobranego z łopat wirnika helikoptera Mi-2.
Źródło:
Journal of Theoretical and Applied Mechanics; 2012, 50, 4; 923-931
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convergence rates of orthogonal series regression estimators
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1208155.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
orthonormal system
nonparametric series regression
least squares method
convergence rate
Opis:
General conditions for convergence rates of nonparametric orthogonal series estimators of the regression function f(x)=E(Y | X = x) are considered. The estimators are obtained by the least squares method on the basis of a random observation sample (Y_i,X_i), i=1,...,n, where $X_i ∈ A ⊂ ℝ^d$ have marginal distribution with density $ϱ ∈ L^1(A)$ and Var( Y | X = x) is bounded on A. Convergence rates of the errors $E_X(f(X)-\widehat f_N(X))^2$ and $\Vert f-\widehat f_N\Vert_∞$ for the estimator $\widehat f_N(x) = \sum_{k=1}^N\widehat c_ke_k(x)$, constructed using an orthonormal system $e_k$, k=1,2,..., in $L^2(A)$ are obtained.
Źródło:
Applicationes Mathematicae; 2000, 27, 4; 445-454
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of a new approach to photovoltaic parameters extraction based on the total least squares method
Autorzy:
Mesbahi, Oumaima
Tlemçani, Mouhaydine
Janeiro, Fernando M.
Hajjaji, Abdeloawahed
Kandoussi, Khalid
Powiązania:
https://bibliotekanauki.pl/articles/2052125.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic modules
parameter extraction
total least squares
MPP
sensitivity analysis
Opis:
The degradation of photovoltaic modules and their subsequent loss of performance has a serious impact on the total energy generation potential. The lack of real-time information on the output power leads to additional losses since the panels may not be operating at their optimal point. To understand the behaviour, numerically simulate the characteristics and identify the optimal operating point of a photovoltaic cell, the parameters of an equivalent electrical circuit must first be identified. The aim of this work is to develop a total least-squares based algorithm which can identify those parameters from the output voltage and current measurements, taking into consideration the uncertainties on both measured quantities. This work presents a comparative study of the Ordinary Least Squares (OLS) and Total Least Squares (TLS) approaches to the estimation of the parameters of a photovoltaic cell.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 751-765
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dekomunizacja zielonogórskich urbanonimów
The decommunization of Zielona Góra’s urbanonyms
Autorzy:
Żuraszek-Ryś, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/1044574.pdf
Data publikacji:
2019-09-15
Wydawca:
Uniwersytet im. Adama Mickiewicza w Poznaniu
Tematy:
urbanonym
decommunization
motivations for changing the names of streets and squares
Opis:
The article describes the process of decommunization of urbanonyms in one of the Polish voivodeship capitals, Zielona Góra. It presents both the changes in naming we are witnessing currently and past ones. During the first removal of communist patrons we still had to deal with the period of the Polish People’s Republic after Stalin’s death and Władysław Gomułka’s coming to power. However, the changes introduced at that time were quite limited and concerned a small number of people who were no longer in power – Stalin and Marshal Rola-Żymierski. The proper decommunization was related to the political transformation after 1989. The previous urbanonyms, based mainly on anthroponyms, were replaced with names referring to people and events that could not be commemorated before and were to be erased from history (e.g. ul. Hanki Sawickiej changed to ul. gen. Okulickiego). In addition, the changes were motivated by the need nto commemorate local activists and heroes, and to highlight the history and topography of the city. The last decommunization was enforced by the enactment of the Act on the Prohibition of Propagation of Communism or Other Totalitarian Regimes and ended quite recently (the last street name change was voted on on March 27, 2018). Four streets in Zielona Góra have been renamed, including two referring to military organizations associated with the communist movement (ul. Armii Ludowej→ ul. Władysława Jagiełły and ul. II Armii → ul. Żołnierzy 2 Armii), and two based on dates (ul. Przylep-22 Lipca → ul. Przylep-Solidarności and ul. Przylep-9 Maja → ul. Przylep-8 Maja). Therefore, in the case of both decommunizations, ideological considerations prevailed, and to a lesser degree so did economic or cultural ones. 
Źródło:
Poznańskie Studia Polonistyczne. Seria Językoznawcza; 2019, 26, 1; 203-216
1233-8672
2450-4939
Pojawia się w:
Poznańskie Studia Polonistyczne. Seria Językoznawcza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Least squares estimator consistency: a geometric approach
Autorzy:
Mexia, João
da Silva, João
Powiązania:
https://bibliotekanauki.pl/articles/729688.pdf
Data publikacji:
2006
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
linear models
least squares estimator
consistency
radial symmetry
generalized polar coordinates
Opis:
Consistency of LSE estimator in linear models is studied assuming that the error vector has radial symmetry. Generalized polar coordinates and algebraic assumptions on the design matrix are considered in the results that are established.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2006, 26, 1; 19-45
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On melancholic magic squares
Autorzy:
Trenkler, Götz
Trenkler, Dietrich
Powiązania:
https://bibliotekanauki.pl/articles/729848.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
magic squares
patterns
group inverse
Moore-Penrose inverse
eigenvalues and eigenvectors
Opis:
Starting with Dürer's magic square which appears in the well-known copper plate engraving Melencolia we consider the class of melancholic magic squares. Each member of this class exhibits the same 86 patterns of Dürer's magic square and is magic again. Special attention is paid to the eigenstructure of melancholic magic squares, their group inverse and their Moore-Penrose inverse. It is seen how the patterns of the original Dürer square to a large extent are passed down also to the inverses of the melancholic magic squares.
Źródło:
Discussiones Mathematicae Probability and Statistics; 2013, 33, 1-2; 111-119
1509-9423
Pojawia się w:
Discussiones Mathematicae Probability and Statistics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Uncertainty Model Of Approximating The Analytical Solution To The Real Case In The Field Of Stress Prediction
Autorzy:
Gutiérrez, R.
Ramírez, M.
Olmeda, E.
Díaz, V.
Powiązania:
https://bibliotekanauki.pl/articles/220703.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
uncertainty
strain gage measurement
stress concentration factor
weighted least squares algorithm
Opis:
Deterministic mechanics has been extensively used by engineers as they needed models that could predict the behavior of designed structures and components. However, modern engineering is now shifting to a new approach where the uncertainty analysis of the model inputs enables to obtain more accurate results. This paper presents an application of this new approach in the field of the stress analysis. In this case, a two-dimensional stress elasticity model is compared with the experimental stress results of five different size tubes measured with resistive strain gages. Theoretical and experimental uncertainties have been calculated by means of the Monte Carlo method and a weighted least square algorithm, respectively. The paper proposes that the analytical engineering models have to integrate an uncertainty component considering the uncertainties of the input data and phenomena observed during the test, that are difficult to adapt in the analytical model. The prediction will be thus improved, the theoretical result being much closer to the real case.
Źródło:
Metrology and Measurement Systems; 2015, 22, 3; 429-442
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oświetlenie dróg publicznych w gminach – planowanie i finansowanie oświetlenia przestrzeni publicznej
Lighting on Public Roads in Municipalities – Planning and Financing of Lighting in Public Areas
Autorzy:
Nowaszczuk, Bożena
Wrona, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/416801.pdf
Data publikacji:
2014-06
Wydawca:
Najwyższa Izba Kontroli
Tematy:
lighting of streets, squares and public roads
costs of electric energy
Opis:
One of the tasks of municipalities is to finance the lighting of streets, squares and public roads located in their area. It is related to both, covering the costs of electric energy consumed by lighting, and financing their construction and maintenance. As the audit conducted by NIK illustrates, municipalities have problems with performing this task in a proper way, stemming mainly from the significant increase of the needs related to the construction of new roads, as well as from unclear legal regulations. In municipalities that have refused to finance lighting of national roads sections, these costs would constitute 60 per cent of the total expenditure in the field.
Źródło:
Kontrola Państwowa; 2014, 59, 3(356); 53-65
0452-5027
Pojawia się w:
Kontrola Państwowa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differentiation of a Fourier series
Autorzy:
Cruz-Santiago, R.
López-Bonilla, J.
López-Vázquez, R.
Powiązania:
https://bibliotekanauki.pl/articles/1177486.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Fejér-Lanczos σ-Factors
Fourier series
Generalized derivative
Least squares method
Opis:
It is very known that if the operator d/dx acts on each term into a convergent Fourier series (FS) then it may result a divergent series. This situation is remedied applying the symmetric derivative to FS, which implies the existence of the important Fejér-Lanczos factors. In this note, we show that the orthogonal derivative also leads to these factors.
Źródło:
World Scientific News; 2018, 102; 188-192
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Least-squares trigonometric regression estimation
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1338814.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
consistent estimator
least squares method
Fourier coefficients
trigonometric polynomial
regression function
Opis:
The problem of nonparametric function fitting using the complete orthogonal system of trigonometric functions $e_k$, k=0,1,2,..., for the observation model $y_i = f(x_{in}) + η_i$, i=1,...,n, is considered, where $η_i$ are uncorrelated random variables with zero mean value and finite variance, and the observation points $x_{in} ∈ [0,2π]$, i=1,...,n, are equidistant. Conditions for convergence of the mean-square prediction error $(1/n)\sum_{i=1}^n E(f(x_{in})-\widehat f_{N(n)}(x_{in}))^2$, the integrated mean-square error $E ‖f-\widehat f_{N(n)}‖^2$ and the pointwise mean-square error $E(f(x)-\widehatf_{N(n)}(x))^2$ of the estimator $\widehat f_{N(n)}(x) = \sum_{k=0}^{N(n)} \widehat c_k e_k(x)$ for f ∈ C[0,2π] and $\widehat c_0,\widehat c_1,...,\widehat c_{N(n)}$ obtained by the least squares method are studied.
Źródło:
Applicationes Mathematicae; 1999, 26, 2; 121-131
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Value added choice Factors influencing value-added agricultural choice within smallholder farming agribusinesses of Gauteng Province in South Africa
Autorzy:
Melembe, Tumiso
Senyolo, Grany Mmatsatsi
Mmbengwa, Victor Mbulaheni
Powiązania:
https://bibliotekanauki.pl/articles/1886397.pdf
Data publikacji:
2021-07-04
Wydawca:
Uniwersytet Przyrodniczy w Poznaniu. Wydawnictwo Uczelniane
Tematy:
agro-processing
ordinary least squares
small holder farmers
value addition
Gauteng
Opis:
This paper investigated factors influencing value addition agricultural choices of smallholder farming agribusinesses in the Gauteng Province, South Africa, using the Ordinary Least Squares regression model. The study used randomly sampled data collected from 102 smallholder farmers by the National Agricultural Marketing Council and the Gauteng Department of Agriculture and Rural Development. Four types of value addition were identified, namely postharvest, food preservation, milling, and post-slaughter. The results revealed that the number of people in the household, permanent workers, and access to training influences smallholder farmers’ choice of post-harvest, food preservation, and post-slaughter value addition. Besides, milling value addition is influenced by the size of the farm, grain, and livestock production, together with access to information and training. These results call for government intervention in promoting agro-processing and value addition activities to encourage farmer participation, income generation, and poverty alleviation, thus improving the farmers’ livelihoods.
Źródło:
Journal of Agribusiness and Rural Development; 2021, 60, 2; 183-191
1899-5241
Pojawia się w:
Journal of Agribusiness and Rural Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization Method Based on Minimization M-Order Central Moments Used In Surveying Engineering Problems
Autorzy:
Cellmer, Sławomir
Bobojć, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2069748.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
Least Squares method
Newton method
objective function
m-estimation
surveying engineering
Opis:
A new optimization method presented in this work – the Least m-Order Central Moments method, is a generalization of the Least Squares method. It allows fitting a geometric object into a set of points in such a way that the maximum shift between the object and the points after fitting is smaller than in the Least Squares method. This property can be very useful in some engineering tasks, e.g. in the realignment of a railway track or gantry rails. The theoretical properties of the proposed optimization method are analyzed. The computational problems are discussed. The appropriate computational techniques are proposed to overcome these problems. The detailed computational algorithm and formulas of iterative processes have been derived. The numerical tests are presented, in order to illustrate the operation of proposed techniques. The results have been analyzed, and the conclusions were then formulated.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2021, 24(1); 39--49
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensor Calibration Design Based on D-Optimality Criterion
Autorzy:
Hajiyev, C.
Powiązania:
https://bibliotekanauki.pl/articles/220607.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sensor
calibration curve
calibration design
D-optimality criterion
least squares method
Opis:
In this study, a procedure for optimal selection of measurement points using the D-optimality criterion to find the best calibration curves of measurement sensors is proposed. The coefficients of calibration curve are evaluated by applying the classical Least Squares Method (LSM). As an example, the problem of optimal selection for standard pressure setters when calibrating a differential pressure sensor is solved. The values obtained from the D-optimum measurement points for calibration of the differential pressure sensor are compared with those from actual experiments. Comparison of the calibration errors corresponding to the D-optimal, A-optimal and Equidistant calibration curves is done.
Źródło:
Metrology and Measurement Systems; 2016, 23, 3; 413-424
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Mixtures Model Approach to Sensitive Questions in Surveys
Autorzy:
Artem, Shcherbina
Rostyslav, Maiboroda
Powiązania:
https://bibliotekanauki.pl/articles/465798.pdf
Data publikacji:
2011
Wydawca:
Główny Urząd Statystyczny
Tematy:
anonymous survey
sensitive questions
maximum likelihood
weighted mean
weighted least squares
Opis:
Observations from mixtures of different subpopulations are common in biological and sociological studies. We consider the case, when the observations are taken from a set of groups containing subjects, which belong to different subpopulations. Proportion of each subpopulation in a group is known and can vary from group to group. Our aim is to estimate the means of an observed variable for subjects, which belong to each subpopulation. In this paper we consider the case, when subpopulations are defined by answers on so called “sensitive questions”. We consider some parametric and nonparametric estimates of the subpopulation means, such as weighted means, maximum likelihood and weighted least squares estimates. Finite sample properties of these estimates are analyzed. Mean square errors of the estimates are compared on simulated data. Some asymptotic results are also given.
Źródło:
Statistics in Transition new series; 2011, 12, 2; 331-344
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and Parameter Estimation of Radar Sea-Clutter with Trimodal Gamma Population
Autorzy:
Terki, Zakia
Mezache, Amar
Chebbara, Fouad
Powiązania:
https://bibliotekanauki.pl/articles/2142297.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
CCDF
estimation
least squares
MLE
modeling
trimodal Gamma model
zlog(z)
Opis:
Real radar data often consist of a mixture of Gaussian and non-Gaussian clutter. Such a situation creates one or more inflexion points in the curve of the empirical cumulative distributed function (CDF). In order to obtain an accurate fit with sea reverberation data, we propose, in this paper, a trimodal gamma disturbance model and two parameter estimators. The non-linear least-squares (NLS) fit approach is used to avoid computational issues associated with the maximum likelihood estimator (MLE) and moments-based estimator for parameters of the mixture model. For this purpose, a combination of moment fit and complementary CDF (CCDF) NLS fit methods is proposed. The simplex minimization algorithm is used to simultaneously obtain all parameters of the model. In the case of a single gamma probability density function, a zlog(z) method is derived. Firstly, simulated life tests based on a gamma population with different shape parameter values are worked out. Then, numerical illustrations show that both MLE and zlog(z) methods produce closer results. The proposed trimodal gamma distribution with moments NLS fit and CCDF NLS fit estimators is validated to be in qualitative agreement with different cell resolutions of the available IPIX database.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 82--90
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A transformer winding deformation detection method based on the analysis of leakage inductance changes
Autorzy:
Jiansheng, L.
Fengbo, T.
Chao, W.
Yuncai, L.
Peng, W.
Mengzhou, Z.
Miao, Y.
Powiązania:
https://bibliotekanauki.pl/articles/140628.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
condition-based maintenance
winding deformation
leakage inductance
partial least squares regression
Opis:
The detection of transformer winding deformation caused by short-circuit current is of great significance to the realization of condition based maintenance. Considering the influence of environment and measurement errors, an online deformation detection method is proposed based on the analysis of leakage inductance changes. First, the operation expressions are derived on the basis of the equivalent circuit and the leakage inductance parameters are identified by the partial least squares regression algorithm. Second, the amount of the leakage inductance samples in a detection time window is determined using the Monte Carlo simulation thought, and then the samples in the confidence interval are obtained. Last, a criteria is built by the mean value changes of the leakage inductance samples and the winding deformation is detected. The online detection method considers the random fluctuation characteristics of the leakage inductance samples, adjust the threshold value automatically, and can quantify the change range to assess the severity. Based on the field data, the distribution of the leakage inductance samples is analyzed to obey the normal function approximately. Three deformation experiments are done by different sub-winding connections and the detection results verify the effectiveness of the proposed method.
Źródło:
Archives of Electrical Engineering; 2015, 64, 2; 333-346
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of b-value variation of earthquakes in Papua New Guinea
Autorzy:
Abong, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/1068605.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
F-ratio
Papua New Guinea
b-value
earthquakes
least squares
temporal variation
Opis:
This study evaluated the b-value variation of earthquakes in Papua New Guinea region. The data used were extracted from International Seismological Centre (ISC), Pipers Lane, Thatcham, Berkshire, United Kingdom. The selected data consisted of earthquakes with Mb ≥ 2.6 for the study area from 1st January 1966 to 31st December 2015 (50 years) with focal depth from 0 – 700 km. The data were analyzed using Least Squares (LS) approximation method and SPSS Software version 20.0. The findings of this study categorized b-value into three groups: High, moderate and low. High b-value varies from 1.01 to 1.35, moderate b-value lies between 0.8 and 1.0 and low b-value varies from 0.63 to 0.80. This indicates that the years where high b-values occurred predominantly consist of many earthquakes of moderate magnitudes; slight decrease in b-value is associated with many earthquakes of large magnitudes and low b-value is associated with many earthquakes of small magnitudes. The b-value for the whole study area was calculated to be 0.91. The research hypothesis revealed that there is a significant difference in the b-value between the decade groups from 1966 to 2015. The F-ratio between the decade groups was found to be 3.776 with significant value of 0.010. The implication of this study is that temporal variation and monitoring of b-values will serve as one of the reliable ways of earthquake prediction in Papua New Guinea.
Źródło:
World Scientific News; 2019, 132; 155-168
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of covariance parameters for GNSS/leveling geoid data by Leave-One-Out validation
Autorzy:
Jarmołowski, W.
Powiązania:
https://bibliotekanauki.pl/articles/298144.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
GNSS
leveling
geoid
least squares collocation
leave-one-out
LOO
covariance
noise
Opis:
The article describes the estimation of covariance parameters in Least Squares Collocation (LSC) by Leave-One-Out (LOO) validation, which is often considered as a kind of cross validation (CV). Two examples of GNSS/leveling (GNSS/lev) geoid data, characterized by different area extent and resolution are applied in the numerical test. A special attention is focused on the noise, which is not correlated in this case. The noise variance is set to be homogeneous for all points. Two parameters in three covariance models are analyzed via LOO, together with a priori noise standard deviation, which is a third parameter. The LOO validation finds individual parameters for different applied functions i.e. different correlation lengths and a priori noise standard deviations. Diverse standard deviations of a priori noise found for individual datasets illustrate a relevance of applying LOO in LSC. Two examples of data representing different spatial resolutions require individual noise covariance matrices to obtain optimal LSC results in terms of RMS in LOO validation. The computation of appropriate a priori noise variance is however difficult via typical covariance function fitting, especially in the case of sparse GNSS/leveling geoid data. Therefore LOO validation may be helpful in describing how the a priori noise parameter may affect LSC result and a posteriori error.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2013, 16(4); 291-307
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
LMS Algorithm Step Size Adjustment for Fast Convergence
Autorzy:
Bismor, D.
Powiązania:
https://bibliotekanauki.pl/articles/177252.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal processing
adaptive algorithms
least mean squares
active noise control
system identification
Opis:
In the areas of acoustic research or applications that deal with not-precisely-known or variable condi- tions, a method of adaptation to the uncertainness or changes is usually necessary. When searching for an adaptation algorithm, it is hard to overlook the least mean squares (LMS) algorithm. Its simplicity, speed of computation, and robustness has won it a wide area of applications: from telecommunication, through acoustics and vibration, to seismology. The algorithm, however, still lacks a full theoretical analysis. This is probabely the cause of its main drawback: the need of a careful choice of the step size – which is the reason why so many variable step size flavors of the LMS algorithm has been developed. This paper contributes to both the above mentioned characteristics of the LMS algorithm. First, it shows a derivation of a new necessary condition for the LMS algorithm convergence. The condition, although weak, proved useful in developing a new variable step size LMS algorithm which appeared to be quite different from the algorithms known from the literature. Moreover, the algorithm proved to be effective in both simulations and laboratory experiments, covering two possible applications: adaptive line enhancement and active noise control.
Źródło:
Archives of Acoustics; 2012, 37, 1; 31-40
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
THE ANALYSIS OF AN INVESTMENT RISK WITHIN EMERGING CAPITAL MARKETS. THE CASE OF THE WARSAW STOCK EXCHANGE
Autorzy:
Kowerski, Mieczyslaw
Powiązania:
https://bibliotekanauki.pl/articles/599410.pdf
Data publikacji:
2010
Wydawca:
Wyższa Szkoła Informatyki i Zarządzania z siedzibą w Rzeszowie
Tematy:
EFFICIENT MARKET HYPOTHESIS
FAMA-FRENCH THREE-FACTOR MODEL
GENERALIZED LEAST SQUARES METHOD
Opis:
The purpose of the paper is to show that the three-factor Fama-French model can be a good instrument for analysis of investment risk on emerging capital markets if, because of the relatively small number of quoted companies, for calculation of the SMB and HML values we applied division of all companies into four portfolios (contrary to Fama – French who propose division of all companies into six portfolios). The usefulness of the above concept was verified on the Warsaw Stock Exchange. The models estimated with the Generalized Least Squares Method on monthly data within the period 1994 – 2008 have the signs of coefficients which are consistent with those of the Fama-French three-factor model and there is no autocorrelation of disturbances and no ARCH effect. Models are relatively high adjusted. Estimated coefficients are also robust. The models fully confirm the thesis posed by Fama and French that in addition to market risk there are two other risk factors which influence the return on investment. These are: risk associated with investing in small companies and risk connected with investing in companies undervalued by the market.
Źródło:
Finansowy Kwartalnik Internetowy e-Finanse; 2010, 6, 4; 1-23
1734-039X
Pojawia się w:
Finansowy Kwartalnik Internetowy e-Finanse
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the substrate consumption rate to the monitoring of distributed parameter bioreactors
Autorzy:
Czeczot, J.
Metzger, M.
Babary, J.
Nihtilae, M.
Powiązania:
https://bibliotekanauki.pl/articles/206652.pdf
Data publikacji:
2001
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
biotechnologia
estymacja metodą najmniejszych kwadratów
biotechnology
distributed parameter systems
least squares estimation
Opis:
This paper deals with the idea of estimation of the substrate consumption rate at each point of the tube of the classical distributed parameter bioreactor and its application to the monitoring of this system. It is shown how to approximate the profile of this parameter on the basis of the orthogonal collocation method and the recursive least-squares procedure with adjustable forgetting factor. Then, it is suggested how to apply this profile for monitoring of the bioreactor work (calculation of the current mass flux of the substrate being reacted in the reactor tube and of the total mass of the substrate reacted in the bioreactor tube during its activity). The idea presented in this paper ivas validated by means of the computer simulation and the results proving its very good performance complete the paper.
Źródło:
Control and Cybernetics; 2001, 30, 1; 81-98
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Self-learning fuzzy predictor of exploitation system operating time
Autorzy:
Smoczek, J.
Szpytko, J.
Powiązania:
https://bibliotekanauki.pl/articles/247106.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
operating time prediction
fuzzy logic
recursive least squares algorithm
overhead travelling crane
Opis:
The probability that a system is capable to operate satisfactorily significantly depends on reliability and maintainability of a system. The disadvantage of classic methods of system availability determining is that the probability of realizing by system tasks with expected quality depends on history of operational states and does not take into consideration actual operational conditions that have strong influence on risk-degree of down-time occurring, while the probability of degradation failure in exploitation system is a function of operating time and actual exploitation conditions. The problem of failures prediction can be solved by applying in diagnostics methods the intelligent computational algorithms. The intelligence computational methods enable to create the diagnosis tools that allow to formulate the prognosis of operating time of a system and predict of failure occurring based on the past and actual information about system's operational state. The paper presents the fuzzy logic approach to forecast the prognoses of the operating time of the exploitation system or its equipments according to the specified exploitation conditions that characterize the system exploitation state at the current time. The fuzzy system was based on the Takagi-Sugeno-Kang type fuzzy implications with singletons specifies in conclusions of rules. The fuzzy inference system input variables are the assumed parameters according to which the current exploitation state of the considered system can be evaluated.
Źródło:
Journal of KONES; 2011, 18, 4; 463-469
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rynki małych miast i wsi o tradycjach miejskich - wartościowe wnętrza krajobrazowe
Market squares of small towns and villages having urban traditions as valuable landscape interiors
Autorzy:
Borcz, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1186886.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Przyrodniczy we Wrocławiu
Tematy:
miasto
wieś
rynek
krajobraz
zabudowa
wartość
town
village
landscape
market squares
value
Opis:
At Lower Silesia many small towns and villages which formerly had civic laws are to be found, but in the course of time they lost them. The considered settlements date back mostly to 13th century, they often went through severe trials, e.g. wars, fires, or floods. They obtained the civic laws as a result of a number of factors, then often they lost them, or sometimes recovered them again. The main elements of small towns are the market square and streets coming out of it. The frontages of the market square mostly have a compact building, often, even in small towns a town hall is to be found in the centre of a market square. The settlements in the piedmont terrains are especially picturesque, the market square forms there an interesting landscape interior. In the conclusion there is pointed out that systems of small towns and villages having urban traditions require a suitable space planning and a conservator's protection.
Źródło:
Architektura Krajobrazu; 2008, 4; 11-17
1641-5159
Pojawia się w:
Architektura Krajobrazu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power spectrum optimization in the design of multisine manoeuvre for identification purposes
Autorzy:
Lichota, P.
Szulczyk, J.
Noreña, D. A.
Vallejo Monsalve, F. A.
Powiązania:
https://bibliotekanauki.pl/articles/279485.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
flight dynamics
optimal input design
multisine excitations
system identification
least squares
maximum likelihood
Opis:
In this paper, two sets of multisine signals are designed for system identification purposes. The first one is obtained without any information about system dynamics. In the second case, the a priori information is given in terms of dimensional stability and control derivatives. Magnitude Bode plots are obtained to design the multisine power spectrum that is optimized afterwards. A genetic algorithm with linear ranking, uniform crossover and mutation operator has been employed for that purpose. Both designed manoeuvres are used to excite the aircraft model, and then system identification is performed. The estimated parameters are obtained by applying two methods: Equation Error and Output Error. The comparison of both investigated cases in terms of accuracy and manoeuvre time is presented afterwards.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 4; 1193-1203
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of Disturbance in Model of Linear Regression Estimated According to Criteria of Least Squares
Analiza zakłóceń w modelu regresji liniowej w porównaniu do klasycznej metody najmniejszych kwadratów
Autorzy:
Wagner, Wiesław
Budka, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1358350.pdf
Data publikacji:
2003
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
linear regression
method of least squares
disturbance
disturbed dependent variable
disturbed independent variable
Opis:
W pracy przedstawiono wyniki analiz numerycznych związanych z estymacją stopnia zakłócenia współczynników występujących w równaniu prostej regresji.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2003, 164; 39-50
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 175

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