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Tytuł:
Analysis of parameters affecting fuel consumption based on statistical modelling
Analiza parametrów wpływających na zużycie paliwa w oparciu o modelowanie statystyczne
Autorzy:
Burdzik, Rafał
Simiński, Dawid
Powiązania:
https://bibliotekanauki.pl/articles/24084912.pdf
Data publikacji:
2023
Wydawca:
Instytut Transportu Samochodowego
Tematy:
fuel consumption
truck
classical method of least squares
zużycie paliwa
samochód ciężarowy
klasyczna metoda najmniejszych kwadratów
Opis:
Fluctuating fuel prices and the importance of road transport in the context of the environmental impact of transport make the research related to fuel consumption analyses still up‑ to‑ date and socially important. The article presents the methodology for determining the statistical model of fuel consumption based on the analysis of the significance of driving parameters. The fleet of trucks (sets of tractor truck and semi‑ trailer) was selected as the research object due to their dominant share in the road commercial transport sector in the transport of goods. In order to calculate determinants of fuel consumption, the classic method of least squares was used, as a result of which an optimal statistical model of fuel consumption was developed using the elimination method. The model developed was also verified based on the real data.
Zmienne ceny paliw oraz znaczenie transportu drogowego w kontekście oddziaływania środowiskowego transportu powodują, że badania związane z analizami zużycia paliwa są ciągle aktualne i istotne społecznie. W artykule przedstawiono metodologię wyznaczania modelu statystycznego zużycia paliwa na podstawie analizy istotności parametrów jazdy. Jako obiekt badań wybrano flotę samochodów ciężarowych (zastawów ciągnik siodłowy i naczepa) z uwagi na ich dominujący udział w sektorze drogowego transportu zarobkowego w przewozie ładunków. W celu wyznaczenia determinant zużycia paliwa zastosowano klasyczną metodę najmniejszych kwadratów, w efekcie której opracowano, metodą eliminacji, optymalny model statystyczny zużycia paliwa. Przeprowadzono także weryfikację opracowanego modelu na podstawie danych rzeczywistych
Źródło:
Transport Samochodowy; 2023, 1; 23--28
1731-2795
Pojawia się w:
Transport Samochodowy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Discrimination of Selected Cold-Pressed and Refined Oils by Untargeted Profiling of Phase Transition Curves of Differential Scanning Calorimetry
Autorzy:
Islam, Mahbuba
Magdalena, Montowska
Emilia, Fornal
Jolanta, Tomaszewska-Gras
Powiązania:
https://bibliotekanauki.pl/articles/16538550.pdf
Data publikacji:
2023-08-02
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
authentication
plant oils
chemometrics
multivariate data analysis
melting profiles
orthogonal partial least squares-discriminant analysis
differential scanning calorimetry
Opis:
The authenticity assessment of edible oils is crucial to reassure consumers of product compliance. In this study, a new approach was taken to combining untargeted profiling by using differential scanning calorimetry (DSC) with chemometric methods in order to distinguish cold-pressed oils (flaxseed, camelina, hempseed) from refined oils (rapeseed, sunflower, soybean). The whole spectrum of DSC melting profiles was considered as a fingerprint of each oil. Flaxseed and hempseed oils exhibited four endothermic peaks, while three peaks with one exothermic event were detected for camelina seed oil. In the case of refined oils, two endothermic peaks were detected for rapeseed oil, three for sunflower oil and four for soybean oil. Thermodynamic parameters, such as peak temperature, peak heat flow and enthalpy, differed for each type of oil. Principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) were used for processing data consisting of the whole spectrum of heat flow variables of melting phase transition. PCA demonstrated a clear separation between refined and cold-pressed oils as well as six individual oils. The OPLS-DA showed a distinct classification in six classes according to the types of oils. High OPLS-DA coefficients including R2X(cum)=0.971, R2(cum)=0.916 and Q2X(cum)=0.887 indicated good fitness of the model for oil discrimination. Variables influence on projection (VIP) plot indicated the most significant variables of the heat flow values detected at temperatures around −29°C, −32°C, −14°C, −10°C, −24°C and −41°C for the differentiation of oils. The study ultimately demonstrated great potential of the untargeted approach of using the whole melting DSC profile with chemometrics for the discrimination of cold-pressed and refined oils.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2023, 73, 3; 224-232
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
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:
Metoda dopasowania funkcji nieliniowej do danych punktów pomiarowych i jej pasmo niepewności
The Method of Fitting a Non-linear Function to Data of Measured Points and its Uncertainty Band
Autorzy:
Puchalski, Jacek
Warsza, Zygmunt Lech
Powiązania:
https://bibliotekanauki.pl/articles/27312460.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
regresja liniowa funkcji nieliniowych
dopasowanie
niepewność
pasmo niepewności
autokorelacja
korelacja wzajemna
ważona ogólna metoda najmniejszych kwadratów
linear regression of non-linear functions
fit
uncertainty
uncertainty band
correlation
weighted total least squares method
Opis:
W pracy przedstawiono propozycję metody wyznaczania parametrów i pasma niepewności funkcji nieliniowej dopasowanej do zmierzonych danych punktów badanych. By ją zlinearyzować trzeba dokonać zamiany jednej lub obu zmiennych określonej funkcji nieliniowej. Następnie metodą regresji liniowej dobrano najkorzystniejsze parametry linii prostej dopasowanej do wartości współrzędnych punktów wg ważonego ogólnego kryterium średniokwadratowego WTLS. Uwzględnia się też współczynniki autokorelacji i korelacji wzajemnej oraz niepewności obu współrzędnych oszacowane na podstawie przewodnika GUM. Z parametrów otrzymanej linii prostej i jej pasma niepewności wynikają poszukiwane parametry funkcji nieliniowej oraz jej pasmo niepewności. Podano przykłady liczbowe wyznaczania parametrów i pasma niepewności dwiema metodami dla jednej z gałęzi paraboli drugiego stopnia oraz dla złożonej funkcji wykładniczej.
The paper presents a method of determining parameters and uncertainty bands of a specific non-linear function fitted to given measured data of examined points. One or both of the variables of this non-linear function are changed so as to linearize it. Using the linear regression method, fined are the most favorable parameters of this straight line for its adjustment to the measured values of the coordinates of points tested according to the weighted total mean square WTLS criterion. Their autocorrelation and cross-correlation coefficients as well as uncertainties estimated according to the rules of the GUM guide are considered. The parameters and the uncertainty band of the non-linear function result from the parameters of this straight line and its uncertainty band. Numerical examples of determining the parameters and uncertainty bands for the branch of a 2nd degree parabola (two methods) and for the complex exponential function are given.
Źródło:
Pomiary Automatyka Robotyka; 2023, 27, 3; 45--55
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Static instability of an inverted plate in channel flow: state-space representation and solution approximation
Autorzy:
Li, P.
Zhang, D.
Cui, J.
Yin, H.
Yang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/38697113.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
inverted cantilevered plate
static aeroelastic instability
channel flow
state-space representation
Glauert’s series
the least squares method
Opis:
Plate-like structures in channel flow are commonly found in engineering. This paper reports a theoretical study on the static aeroelastic instability of an inverted cantilevered plate in an inviscid channel flow through the state space. This study begins with the kernel function of the flow potential determined in the Fourier domain with the help of the mirror image method. Then, the instability equation is derived from the operator theory and transformed in the state space. Finally, with Glauert’s expansion, model functions, and error functions, the instability problem of such a plate has been modeled as a mathematical function approximation problem and solved by the least squares method. The derived instability equation is considered at the continuum level of description, and no approximation appears at the first equation level. The convergence and reliability of the proposed modeling and its solutions approximation are entirely tested, and it can successfully predict the instability boundary, behavior, and the channel effect. Numerical results show that the decreased channel height and asymmetric plate placement in the channel significantly decrease the critical flow velocity. The plate instability modes are close to the plate’s first natural ones and not sensitive to the channel parameters. This conclusion allows further theoretical exploration of a semi-analytical approximation of the instability boundary from the obtained instability equation. The current modeling strategy in a continuum sense may provide a new idea and essential reference for other instability problems.
Źródło:
Archives of Mechanics; 2023, 75, 6; 695-727
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlations for the thermal conductivity of selected steel grades as a function of temperature in the range of 0–800◦C
Autorzy:
Wyczółkowski, Rafał
Strychalska, Dominika
Bagdasaryan, Vazgen
Powiązania:
https://bibliotekanauki.pl/articles/2134935.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermal conductivity
heat transfer
least squares method
thermal conduction analysis
thermal treatment of steel
Opis:
Reliable knowledge of thermo-physical properties of materials is essential for the interpretation of solidification behaviour, forming, heat treatment and joining of metallic systems. It is also a precondition for precise simulation calculations of technological processes. Numerical calculations usually require the knowledge of temperature dependencies of three basic thermo-physical properties: thermal conductivity, heat capacity and density. The objective of this work is to find a correlation that fits the thermal conductivity of selected steel grades as a function of temperature (within the range of 0–800◦C) and carbon content (within the range of 0.1–0.6%). The starting point for the analysis are the experimental data on thermal conductivity taken from literature. Using the method of least squares it was possible to fit an equation which allows calculating the thermal conductivity of steel depending on the temperature and carbon content. Two kinds of equations have been analyzed: a linear one (a linear model) and a second degree polynomial (a non-linear model). The thermal conductivity obtained by linear and nonlinear models varies on average from the measured values by 3% and 2.6% respectively.
Źródło:
Archives of Thermodynamics; 2022, 43, 3; 29--45
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Disentangling the impact of ICT adoption on SMEs performance: the mediating roles of corporate social responsibility and innovation
Autorzy:
León-Gómez, Ana
Santos-Jaén, Jose Manuel
Ruiz-Palomo, Daniel
Palacios-Manzano, Mercedes
Powiązania:
https://bibliotekanauki.pl/articles/19322605.pdf
Data publikacji:
2022
Wydawca:
Instytut Badań Gospodarczych
Tematy:
information and communication technologies
ICT
corporate social responsibility
CSR
innovation
firm performance
Partial Least Squares-Structural Equations Modeling-PLS-SEM
Opis:
Research background: The literature on the effects of Information and Communication Technologies (ICT) on performance is extensive and shows a significant positive effect. Likewise, the use of ICT to facilitate and report on Corporate Social Responsibility (CSR) practices implemented by Small and Medium Enterprises (SMEs) contributes to improve business performance. Moreover, through innovative activities, firms also obtain competitive advantages that impact positively on their performance, even more so when they are impacted by CSR. For this reason, it is expected that the adoption of ICTs in companies through a CSR-oriented strategy will increase their impact on business performance.   Purpose of the article: This article tries to examine how ICT affects SMEs' performance through CSR and innovation. Methods: We tested our hypotheses using a sample of 2,825 Spanish SMEs and by applying a Partial Least Squares Path Modeling (PLS-PM) with a double confirmatory and predictive purpose: to identify the causal relationships between latent variables, and to evaluate the ability of the model to make predictions for individual cases. Findings & value added: The results show that CSR-oriented ICT impacts innovation by changing strategies and business model in companies. Moreover, the implementation of CSR practices gave them competitive advantages to increase their performance. We highlight how innovation gives companies greater capacity to respond to changes in their environment and how innovation positively impacts the link between CSR and performance. Finally, our research makes two significant contributions to the literature by incorporating two sequential mediating effects into the model. On the one hand, the indirect effect of ICT on innovation through CSR. On the other hand, the indirect effect of CSR on SME performance through innovation.
Źródło:
Oeconomia Copernicana; 2022, 13, 3; 831-866
2083-1277
Pojawia się w:
Oeconomia Copernicana
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exploring potential drivers of innovation-related activities in Poland: evidence from Polish business clusters
Autorzy:
Kuczewska, Joanna
Tomaszewski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/22443142.pdf
Data publikacji:
2022
Wydawca:
Instytut Badań Gospodarczych
Tematy:
clusters
cooperation
innovativeness
cluster leader
cluster localization
Partial Least Squares-Structural Equation Modelling
PLS-SEM
Opis:
Research background: Innovations are introduced by competitive companies. One of the most common methods, increasingly used by companies, is organizing clusters or cluster initiatives operating within a specialized sector, competing with each other, exploiting the potential of cooperation and its impact on creating new business ideas. However, these efforts could be unviable due to the lack of an effective leader of the group. One should underline a crucial role of the leader in such an organized network, since the leader makes improvements and takes initiatives for all the network and its partners. These concepts prompt us to undertake the research on the role of clusters? characteristics on enhancing willingness to innovate in general. This study aims to point out the main characteristics of clusters and to investigate their impact on companies? innovativeness. The main problem to address is the magnitude of specific effects that might boost introducing new solutions in firms? networks. Purpose of the article: The purpose of this study is to investigate the impact of factors describing cluster environment (characteristics like cooperation within clusters and beyond them, incentives of a leader, and localization factors) that might affect the innovativeness of companies. Methods: The authors collected data using questionnaire. This type of primary source enables the authors to construct a model consisting of latent variables such as incentives of coordinator of cluster or cluster initiative, cooperation of firms with local authorities, cooperation between entrepreneurs, or localization. The results are subject to the Structural Equation Modelling (SEM) analysis. Findings & value added: The conducted analysis leads to several findings. Firstly, incentives provided by the cluster coordinator enable companies to increase the willingness to introduce innovations in general. Secondly, however, the influence of other cluster characteristics on the propensity to innovate for firms functioning within specific Polish business clusters is scant. These findings point to the fact that actions leading to assign the official coordinator of a cluster need to be done, as it should result in better flow of knowledge, more symmetric information among companies within cluster, and more productive and innovative way of functioning firms in general. Regarding innovation clusters (and regional innovation systems), these actions need to be supported by forming policy on regional level, because effective clusters would induce more competitive regional economy in long-term scenario.
Źródło:
Equilibrium. Quarterly Journal of Economics and Economic Policy; 2022, 17, 3; 775-801
1689-765X
2353-3293
Pojawia się w:
Equilibrium. Quarterly Journal of Economics and Economic Policy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Książka Roku 2021. Bogdan Nowak, Jakub Żygawski, Zamość. Ulice i place (z wykorzystaniem kart pocztowych z kolekcji Stanisława Rudego), Wydawnictwo: Archiwum Państwowe w Zamościu, Książnica Zamojska im. Stanisława Kostki Zamoyskiego, Zamość 2021, ss. 253, ISBN 978-83-949666-1-4
A Book of the Year 2021. The Book Review: Bogdan Nowak, Jakub Żygawski, Zamość. Ulice i place (z wykorzystaniem kart pocztowych z kolekcji Stanisława Rudego), the Publisher: The State Archives in Zamość, Stanisław Kostka Zamoyski Library in Zamość, Zamość, 2021, ss. 253,
Autorzy:
Polańska, Ewelina
Powiązania:
https://bibliotekanauki.pl/articles/26850546.pdf
Data publikacji:
2022
Wydawca:
Akademia Zamojska
Tematy:
Zamość
streets
squares
plans
Jakub Żygawski
Bogdan Nowak
book of the year 2021
The State Archives in Zamość
ulice
place
plany
książka roku 2021
Archiwum Państwowe w Zamościu
Źródło:
Facta Simonidis; 2022, 15, 2; 159-160
1899-3109
Pojawia się w:
Facta Simonidis
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:
On the Analysis of Correlation Between Nominal Data and Numerical Data
Autorzy:
Gniazdowski, Zenon
Powiązania:
https://bibliotekanauki.pl/articles/2163406.pdf
Data publikacji:
2022-12
Wydawca:
Warszawska Wyższa Szkoła Informatyki
Tematy:
nominal data
numerical data
numerical coding of nominal data
complex random variable
correlation coefficient
complex correlation
complex least squares method
Opis:
The article investigates the possibility of measuring the strength of a linear correlation relationship between nominal data and numerical data. Correlation coefficients for variables coded with real numbers as well as for variables coded with complex numbers were studied. For variables coded with real numbers, unambiguous measures of real linear correlation were obtained. In the case of complex coding, it has been observed that the obtained complex correlation coefficients change with the permutation of the phases in the complex numbers used to code classes of elements with equal cardinalities. It was found that a necessary condition for linear correlation is the possibility of linear ordering of a set with data. Since linear order is not possible in the set of complex numbers, complex correlation coefficients cannot be used as a measure of linear correlation. In the event of such a situation, a substitute action was suggested that would prevent equal cardinality of classes of identical elements contained in the set with nominal data. This action would consist in the correction of data, analogous to the correction during preprocessing or cleaning of data containing missing or outlier values.
Źródło:
Zeszyty Naukowe Warszawskiej Wyższej Szkoły Informatyki; 2022, 16, 27; 57-82
1896-396X
2082-8349
Pojawia się w:
Zeszyty Naukowe Warszawskiej Wyższej Szkoły Informatyki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Segmentation and estimation of claim severity in motor third-party liability insurance through contrast analysis
Autorzy:
Reiff, Marian
Šoltés, Erik
Komara, Silvia
Šoltésová, Tatiana
Zelinová, Silvia
Powiązania:
https://bibliotekanauki.pl/articles/22443156.pdf
Data publikacji:
2022
Wydawca:
Instytut Badań Gospodarczych
Tematy:
general linear model
claim severity
motor third party liability insurance
least squares means
contrast analysis
Opis:
Research background: Using the marginal means and contrast analysis of the target variable, e.g., claim severity (CS), the actuary can perform an in-depth analysis of the portfolio and fully use the general linear models potential. These analyses are mainly used in natural sciences, medicine, and psychology, but so far, it has not been given adequate attention in the actuarial field. Purpose of the article: The article's primary purpose is to point out the possibilities of contrast analysis for the segmentation of policyholders and estimation of CS in motor third-party liability insurance. The article focuses on using contrast analysis to redefine individual relevant factors to ensure the segmentation of policyholders in terms of actuarial fairness and statistical correctness. The aim of the article is also to reveal the possibilities of using contrast analysis for adequate segmentation in case of interaction of factors and the subsequent estimation of CS. Methods: The article uses the general linear model and associated least squares means. Contrast analysis is being implemented through testing and estimating linear combinations of model parameters. Equations of estimable functions reveal how to interpret the results correctly. Findings & value added: The article shows that contrast analysis is a valuable tool for segmenting policyholders in motor insurance. The segmentation's validity is statistically verifiable and is well applicable to the main effects. Suppose the significance of cross effects is proved during segmentation. In that case, the actuary must take into account the risk that even if the partial segmentation factors are set adequately, statistically proven, this may not apply to the interaction of these factors. The article also provides a procedure for segmentation in case of interaction of factors and the procedure for estimation of the segment's CS. Empirical research has shown that CS is significantly influenced by weight, engine power, age and brand of the car, policyholder's age, and district. The pattern of age's influence on CS differs in different categories of car brands. The significantly highest CS was revealed in the youngest age category and the category of luxury car brands.
Źródło:
Equilibrium. Quarterly Journal of Economics and Economic Policy; 2022, 17, 3; 803-842
1689-765X
2353-3293
Pojawia się w:
Equilibrium. Quarterly Journal of Economics and Economic Policy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation modeling for evaluation of efficiency of observed ship coordinates
Autorzy:
Vorokhobin, I.
Burmaka, I.
Fusar, I.
Burmaka, O.
Powiązania:
https://bibliotekanauki.pl/articles/2172471.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
ship coordinates
observed ship coordinates
simulation modeling
lines of position
LOP errors
method of least squares
Opis:
Simulation computer modeling was used to evaluate the efficiency of the vessel’s observed coordinates using the mixed laws of distribution errors of the first and second type for lines of position (LOP). Simulation modeling showed good convergence of evaluation of efficiency calculated by analytical expressions and obtained by simulation. A graphical depiction of the observed points’ deviation relative to the mathematical expectation in the case of distribution of LOP errors of both types according to mixed laws is obtained by the method of least squares and the method of maximum likelihood estimation.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 1; 137--141
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new reciprocal Rayleigh extension: properties, copulas, different methods of estimation and a modified right-censored test for validation
Autorzy:
Yousof, Haitham M.
Ali, M. Masoom
Goual, Hafida
Ibrahim, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/1827545.pdf
Data publikacji:
2021-09-06
Wydawca:
Główny Urząd Statystyczny
Tematy:
Xgamma model
reciprocal Rayleigh model
simulations
bootstrapping
Farlie Gumbel Morgenstern copula
least squares
Cramer-Von-Mises
Ali-Mikhail-Haq copula
convexity
concavi
Opis:
In this article, a new reciprocal Rayleigh extension called the Xgamma reciprocal Rayleigh model is defined and studied. The relevant statistical properties are derived, and the useful results related to the convexity and concavity are addressed. We discussed the estimation of the parameters using different estimation methods such as the maximum likelihood estimation method, the ordinary least squares estimation method, the weighted least squares estimation method, the Cramer-Von-Mises estimation method, and the bootstrapping method. A simulation study was conducted to assess the performances of the proposed estimation methods are investigated through a simulation study. Many bivariate and multivariate type model have also been derived based on Farlie-Gumbel-Morgenstern copula, the Clayton copula, Renyi's entropy copula and the Ali-Mikhail-Haq copula. A modified Nikulin-Rao-Robson test for right-censored validation is applied to a censored real data set.
Źródło:
Statistics in Transition new series; 2021, 22, 3; 99-121
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Direct least squares and derivative-free optimisation techniques for determining mine-induced horizontal ground displacement
Autorzy:
Rusek, Janusz
Tajduś, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/2090675.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
horizontal ground displacement
mining
direct least squares
derivative-free optimisation
genetic algorithms
differential evolution
particle swarm optimization
przemieszczenie poziome gruntu
górnictwo
optymalizacja bez pochodnych
optymalizacja roju cząstek
algorytmy genetyczne
ewolucja różnicowa
bezpośrednie najmniejsze kwadraty
Opis:
The paper presents the results of analyses concerning a new approach to approximating trajectory of mining-induced horizontal displacements. Analyses aimed at finding the most effective method of fitting data to the trajectory of mining-induced horizontal displacements. Two variants were made. In the first, the direct least square fitting (DLSF) method was applied based on the minimization of the objective function defined in the form of an algebraic distance. In the second, the effectiveness of differential-free optimization methods (DFO) was verified. As part of this study, the following methods were tested: genetic algorithms (GA), differential evolution (DE) and particle swarm optimization (PSO). The data for the analysis were measurements of on the ground surface caused by the mining progressive work at face no. 698 of the German Prospel-Haniel mine. The results obtained were compared in terms of the fitting quality, the stability of the results and the time needed to carry out the calculations. Finally, it was found that the direct least square fitting (DLSF) approach is the most effective for the analyzed registration data base. In the authors’ opinion, this is dictated by the angular range in which the measurements within a given measuring point oscillated.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 1; e135840, 1--12
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 175

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