Search results

1

{Depthproc} Package in Multivariate Time Series Mining

100%

Kosiorowski D., Bocian M., Węgrzynkiewicz A., Zawadzki Z., Cracow University of Economics

Acta Universitatis Lodziensis. Folia Oeconomica

|

2013

|

vol. 286

EN

In this paper we present our novel R package {depthproc} which implements several multivariate statistical procedures induced by statistical depth functions and we discuss some examples and applications of the package in data mining concerning the multivariate time series.

PL

W artykule przedstawiamy pakiet środowiska R naszego autorstwa o nazwie {DepthProc}. Pakiet zawiera implementacje kilku wielowymiarowych procedur statystycznych indukowanych przez statystyczne funkcje głębi. Przedstawiamy przykłady zastosowań pakietu w eksploracyjnej analizie wielowymiarowego szeregu czasowego.

2

Robustness of The Confidence Interval for At-Risk-Of-Poverty-Rate

100%

Zieliński W.

Statistics in Transition new series

|

2011

|

vol. 12

|

issue 1

115-126

EN

Zieliński (2009) constructed a nonparametric interval for At-Risk-of-Poverty-Rate. It appeared that the confidence level of the interval depends on the underlying distribution of the income. For some distributions (e.g. lognormal, gamma, Pareto) the confidence level may be smaller than the nominal one. The question is, what is the largest deviance from the nominal level? In the paper, a more general problem is considered, i.e. the problem of robustness of the confidence level of the confidence interval for binomial probability. The worst distribution is derived as well as the smallest true confidence level is calculated. Some asymptotic remarks (sample size tends to infinity) are also given.

3

Robustness of randomisation tests as alternative analysis methods for repeated measures design

88%

Oladugba A. V., Obasi A. J., Asogwa O. C.

Statistics in Transition new series

|

2022

|

vol. 23

|

issue 4

77-90

EN

Randomisation tests (R-tests) are regularly proposed as an alternative method of hypothesis testing when assumptions of classical statistical methods are violated in data analysis. In this paper, the robustness in terms of the type-I-error and the power of the R-test were evaluated and compared with that of the F-test in the analysis of a single factor repeated measures design. The study took into account normal and non-normal data (skewed: exponential, lognormal, Chi-squared, and Weibull distributions), the presence and lack of outliers, and a situation in which the sphericity assumption was met or not under varied sample sizes and number of treatments. The Monte Carlo approach was used in the simulation study. The results showed that when the data were normal, the R-test was approximately as sensitive and robust as the F-test, while being more sensitive than the F-test when data had skewed distributions. The R-test was more sensitive and robust than the F-test in the presence of an outlier. When the sphericity assumption was met, both the R-test and the F-test were approximately equally sensitive, whereas the R-test was more sensitive and robust than the F-test when the sphericity assumption was not met.

4

Computer integrated manufacturing and management systems. An emerging application of control and management

88%

Lewoc J. B., Izworski A., Skowroński S., Kieleczawa A., Dimirovski G., Chomiak-Orsa I.

Informatyka Ekonomiczna

|

2013

|

issue 1(27)

33-45

EN

An approach to factory automation is the basis for a case study of Computer Integrated Manufacturing and Management systems (CIMMs). The paper presents some experience in large-scale systems and the current state-of-the-art for the domain. A feasible approach is proposed, based on prospective user expectations and the system development with the use of so-called first thread for which the standards facilitating the development of subsequent systems should be developed, and people acquainted with both manufacturing and management problems should be educated. There is also depicted some research work intended for facilitating the design and implementation of future CIMMs.

5

The Main Faces of Robustness

88%

Boniolo G., Andreoletti M., Boem F., Ratti E.

Dialogue and Universalism

|

2017

|

issue 3

157-172

EN

In the last decade, robustness has been extensively mentioned and discussed in biology as well as in the philosophy of the life sciences. Nevertheless, from both fields, someone has affirmed that this debate has resulted in more semantic confusion than in semantic clearness. Starting from this claim, we wish to offer a sort of prima facie map of the different usages of the term. In this manner we would intend to predispose a sort of “semantic platform” which could be exploited by those who wish to discuss or simply use it. We do this by starting from a core distinction between the robustness of representations, which is a philosophy of science issue, and the representations of robustness, which instead pertains to science. We illustrate our proposal with examples from biology, physics and mathematics.

6

Wybrane zastosowania głębi studenta w odpornej analizie statystycznej

75%

Kosiorowski D.

Folia Oeconomica Cracoviensia

|

2010

|

vol. 51

27-55

EN

In this paper we present selected application of Mizera & Muller location — scale depth. We focus our attention on a Student depth function and propose several statistical procedures based on that statistical depth function.

7

Outliers vs Robustness in Nonparametric Methods of Regression

63%

Trzęsiok J.

Acta Universitatis Lodziensis. Folia Oeconomica

|

2018

|

vol. 4

|

issue 337

99-109

PL

Artykuł poświęcony jest zagadnieniu odporności metod regresji na obserwacje odstające występujące w zbiorze danych. W pierwszej części przedstawiono wybrane metody identyfikacji obserwacji nietypowych. Następnie badano odporność trzech nieparametrycznych metod regresji: PPR, POLYMARS i RANDOM FORESTS. Analiz dokonano za pomocą procedur symulacyjnych na zbiorach danych, w których wykryto obserwacje odstające. Mimo dosyć powszechnych przekonań o odporności regresji nieparametrycznej okazało się, że modele zbudowane na całych zbiorach danych mają istotnie mniejsze zdolności predykcyjne niż modele uzyskane na zbiorach, z których usunięto obserwacje nietypowe.

EN

The article addresses the question of how robust methods of regression are against outliers in a given data set. In the first part, we presented the selected methods used to detect outliers. Then, we tested the robustness of three nonparametric methods of regression: PPR, POLYMARS, and RANDOM FORESTS. The analysis was conducted applying simulation procedures to the data sets where outliers were detected. Contrary to a relatively common conviction about the robustness of nonparametric regression, the study revealed that the models built on the basis of complete data sets represent a significantly lower predictive capability than models based on the sets from which outliers were discarded.

8

Perspectivism and special relativity

63%

Khalili M.

Teorie vědy (Theory of Science)

|

2021

|

vol. 43

|

issue 2

191-217

EN

Th e special theory of relativity holds signifi cant interest for scientifi c perspectivists. In this paper, I distinguish between two related meanings of “perspectival,” and argue that reference frames are perspectives, provided that perspectival means “being conditional” rather than “being partial.” Framedependent properties such as length, time duration, and simultaneity, are not partially measured in a reference frame, but their measurements are conditional on the choice of frame. I also discuss whether the constancy of the speed of light depends on perspectival factors such as the idealized defi nition of the speed of light in a perfect vacuum and the Einstein synchronization convention. Furthermore, I argue for the view that the constancy of its speed is a robust property of light according to the conditions of currently acceptable experimental setups pertaining to special relativity, and conclude that this view supports perspectivism.

CS

Speciální teorie relativity je obzvláště zajímavá z hlediska vědeckého perspektivismu. V tomto článku rozliším dva související významy pojmu „perspektiva“ a pokusím se ukázat, že vztažné soustavy lze chápat jako perspektivy za předpokladu, že perspektivou rozumíme spíše „být podmíněný“, a nikoli „být dílčí“. Vlastnosti závislé na vztažné soustavě, jako je délka, časové trvání a simultánnost, nejsou v dané vztažné soustavě měřeny neúplně, ale jejich měření jsou podmíněna výběrem vztažné soustavy. Rovněž se budu zabývat otázkou, zda stálost rychlosti světla závisí na perspektivních faktorech, jako je idealizovaná defi nice rychlosti světla v dokonalém vakuu a Einsteinova synchronizační konvence. Na závěr se pokusím ukázat, že konstantní rychlost je robustní vlastností světla dle podmínek aktuálně přijímaných experimentů týkajících se speciální relativity a že tento pohled podporuje perspektivismus.

Refine search results