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1
Content available remote Statistical Insights: Analyzing Shock Models, Reliability Operations and Testing Exponentiality for NBRUmgf Class of Life Distributions
Bakr M. E., El-Atfy E. S., Balogun Oluwafemi Samson, Tashkandy Yusra A., Gadallah A. M.
Eksploatacja i Niezawodność
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2024
|
Vol. 26, no. 2
art. no. 184185
EN
This study focuses on an innovative life distribution category known as the 'New Better than Renewal used in Moment Generating Function' (NBRUmgf) class. It explores the relationships between this particular aging model and established aging categories, and its applicability within a shock model. Moreover, it investigates the consistency of this aging concept through specific reliability operations, which are pivotal tools in reliability engineering. The research involves computing Pitman's asymptotic efficiencies for this testing method and compares them with alternative approaches. Additionally, the study presents an extensive table of percentiles for the test statistic associated with this proposed technique. To underscore the significance of the study's findings, various real-world datasets are employed, demonstrating the efficacy of our test methodology across diverse types of actual data.
2
Content available Frequentist inference on traffic intensity of M/M/1 queuing system
Dutta Kaustav, Choudhury Amit
Operations Research and Decisions
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2023
|
Vol. 33, No. 1
21--34
EN
When we study any queuing system, the performance measures reflect different features of the system. In the classical M/M/1 queuing system, traffic intensity is perhaps the most important performance measure. We propose a fresh and simple estimator for the same and show that it has nice properties. Our approach is frequentist. This approach has the dual advantage of practical usability and familiarity. Our proposed estimator is attractive as it possesses desirable properties. We have shown how our estimator lends itself to testing of hypothesis. Confidence intervals are constructed. Sample size determination is also discussed. A comparison with a few similar estimators is also performed.
3
Content available 20 years of the Grammar Matrix: cross-linguistic hypothesis testing of increasingly complex interactions
Zamaraeva Olga, Curtis Chris, Emerson Guy, Fokkens Antske, Goodman Michael Wayne, Howell Kristen, Trimble Thomas .J., Bender Emily M.
Journal of Language Modelling
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2022
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Vol. 10, No.1
49--137
EN
The Grammar Matrix project is a meta-grammar engineering framework expressed in Head-driven Phrase Structure Grammar (HPSG) and Minimal Recursion Semantics (MRS). It automates grammar implementation and is thus a tool and a resource for linguistic hypothesis testing at scale. In this paper, we summarize how the Grammar Matrix grew in the last decade and describe how new additions to the system have made it possible to study interactions between analyses, both monolingually and cross-linguistically, at new levels of complexity.
4
Content available Statistical inferences in material selection of a polymer matrix for natural fiber composites
Noryani M., Sapuan M. S., Mastura M. T., Zuhri M. M. Y., Zainudin E. S.
Polimery
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2020
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T. 65, nr 2
105--114
EN
In this paper, statistical inferences in material selection of polymer matrix for natural fiber composite are presented. Hypothesis testing and confidence interval were used to evaluate the suitability of the sample for use as a matrix in natural fiber reinforced composites. The screening process for material selection was carried out using a stepwise regression method. Then, the ranking process in material selection was conducted using an estimation of performance score (PS) for mechanical properties such as impact strength (IS), elongation at break (E) and tensile strength (TS). Ten types of polymer were involved in the study. The final selection revealed that polyamide (PA6), polyurethanes (PUR) and polypropylene (PP) are the potential candidates to manufacture hand-brake levers according to IS, E and TS, respectively. Here, it was found that the score for Tp (thermoplastic) is better than Ts (thermoset) in terms of IS. In contrast, the Ts offered a better score result than, Tp, with respect to E and TS. The results of statistical measurements using statistical modelling prove that the data analysis can be used as a part of the decision making in material selection.
PL
Opisano wnioskowanie statystyczne dotyczące wyboru materiału osnowy polimerowej kompozytu z włóknami naturalnymi. Testy hipotez statystycznych i przyjęte przedziały ufności służyły do oceny próbki pod względem przydatności do zastosowania w charakterze osnowy polimerowej w kompozycie wzmocnionym włóknem naturalnym. Selekcji materiałów dokonano przy użyciu metody regresji krokowej, następnie uszeregowano wybrane materiały z wykorzystaniem rankingu oceny (PS) właściwości mechanicznych, takich jak: udarność (IS), wydłużenie przy zerwaniu (E) i wytrzymałość na rozciąganie (TS). Wyselekcjonowano wstępnie 10 rodzajów polimerów zaliczanych do grup polimerów termoplastycznych (Tp) i termoutwardzalnych (Ts). Wnioskowanie statystyczne wykazało, że poliamid (PA6), poliuretany (PUR) i polipropylen (PP) są potencjalnie korzystnymi osnowami polimerowymi do wytwarzania dźwigni hamulca ręcznego. Stwierdzono, że polimery z grupy Tp wykazują lepszą udarność niż polimery z grupy Ts. Natomiast materiały Ts charakteryzują korzystniejsze wartości wydłużenia przy zerwaniu i wytrzymałości na rozciąganie niż ich odpowiedniki z grupy Tp. Wyniki przeprowadzonej analizy danych z zastosowaniem modelowania statystycznego dowodzą, że metoda ta może być pomocna przy wyborze materiału odpowiedniego do planowanej aplikacji.
5
Content available remote A reverse to the Jeffreys-Lindley paradox
Pestman W. R., Tuerlinckx F., Vanpaemel W.
Probability and Mathematical Statistics
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2018
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Vol. 38, Fasc. 1
243--247
EN
In this paper the seminal Jeffreys-Lindley paradox is regarded from a mathematical point of view.We show that in certain scen arios the paradox may emerge in a reverse direction.
6
Content available Information about dynamics of the sea surface as a means to improve safety of the unmanned vessel at sea
Przyborski M.
Polish Maritime Research
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2016
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nr 4
3--7
EN
One of the fundamental states of the sea surface is its heave. Despite of years of the intense scientific inquiry, no clear understanding of the influence of this aspect on the dynamics of the sea environment has emerged. The separation of two nearby fluid elements which one may observed for example as a free floating of small objects on the sea surface (rescuers on the rough sea or small research vessels) is caused by the interaction of different components. On the other hand one may say that the heave of the sea is also a summary interaction of a few components describing the dynamics of the sea. Therefore it is the most important aspect, which influenced the dispersion phenomenon. This observation has important consequences for many different problems as for example conducting Search and Rescue missions and using unmanned ships. We would like to present results of our experiment focused on finding the answer to question about nature of the heave of the sea and its influence on safety of Unmanned Surface Vessels (USV).
7
Content available Hypothesis Testing to Confirm the Influence of Technological Parameters on Poor Quality Production
Lakomá R., Čamek L.
Archives of Metallurgy and Materials
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2014
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Vol. 59, iss. 3
1063--1067
EN
This report addresses some chosen statistical methods that could be used to confirm and set up the required functions of technology in foundry companies where parts are cast by the low-wax casting method, whereas these chosen statistical methods are intended to reduce poor quality of produced parts. This research was made on a practical example. Utilization of hypothesis testing methods was examined in order to confirm technological parameters having some influence on the products quality. The data were compared before and after the implementation of changes aimed at reduction of poor quality produced parts in the wax department. The results confirmed that the implemented change had a statistically conclusive influence.
PL
Artykuł przybliża niektóre wybrane metody statystyczne, które można wykorzystać w celu sprawdzenia ustawień wymaganych funkcji w technologii odlewania metodą wosku traconego, do zmniejszenia wad produkcji. Badania przeprowadzono na konkretnym przykładzie. Zbadano wykorzystanie metod testowania hipotez w celu sprawdzenia parametrów technologicznych wpływających na jakość odlewów. Porównano dane przed i po wprowadzeniu zmian w celu ograniczenia wad produkcji w dziale woskowni. Wyniki potwierdziły, że wprowadzona zmiana miała statystycznie udokumentowany wpływ.
8
Content available Improving quality of statistical process control by dealing with non-normal data in automotive industry
Andrássyová Z., Paulicek T., Pichna P., Kotus M.
Management Systems in Production Engineering
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2012
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nr 3 (7)
26-30
EN
Study deals with an analysis of data to the effect that it improves the quality of statistical tools in processes of assembly of automobile seats. Normal distribution of variables is one of inevitable conditions for the analysis, examination, and improvement of the manufacturing processes (f. e.: manufacturing process capability) although, there are constantly more approaches to non-normal data handling. An appropriate probability distribution of measured data is firstly tested by the goodness of fit of empirical distribution with theoretical normal distribution on the basis of hypothesis testing using programme StatGraphics Centurion XV.II. Data are collected from the assembly process of 1st row automobile seats for each characteristic of quality (Safety Regulation -S/R) individually. Study closely processes the measured data of an airbag´s assembly and it aims to accomplish the normal distributed data and apply it the statistical process control. Results of the contribution conclude in a statement of rejection of the null hypothesis (measured variables do not follow the normal distribution) therefore it is necessary to begin to work on data transformation supported by Minitab15. Even this approach does not reach a normal distributed data and so should be proposed a procedure that leads to the quality output of whole statistical control of manufacturing processes.
PL
W artykule dotyczącym metod i technik prognozowania wartości kluczowych wskaźników efektywności obsługi (ang. Key Performance Indicators) zdefiniowano oraz sklasyfikowano te wskaźniki. Przedstawiono wymagania oraz sposób doboru wskaźników KPI. Dokonano przeglądu, a także scharakteryzowano metody i techniki prognozowania stanu organizacji utrzymania ruchu. Przedstawiono koncepcję wykorzystania wybranych metod oraz narzędzi gromadzenia oraz przetwarzania danych dla potrzeb prognozowania tego stanu.
9
Odporna klasyfikacja sygnałów FSK za pomocą modelu regresji liniowej
Gajo Z., Linczuk M.
Elektronika : konstrukcje, technologie, zastosowania
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2009
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Vol. 50, nr 8
57-61
PL
W pracy przedstawiono odporną regułę decyzyjną utworzoną na bazie modelowania regresyjnego, służącą do klasyfikacji znanych sygnałów w obecności zakłóceń impulsowych modelowanych rozkładami a-stabilnymi o ciężkich ogonach. Reguła ta prowadzi do zadawalających rezultatów klasyfikacji nawet dla szumów o dużej impulsowości i dla stosunkowo niewielkich stosunków sygnału do szumu, co potwierdziły badania symulacyjne. Ze względu na trudności numeryczne związane z modelowaniem regresyjnym ograniczeniem metody jest wymaganie liniowej niezależności klasyfikowanych sygnałów. Nie naruszając tego założenia, w pracy przedstawiono przykłady zastosowania metody dla sygnałów FSK.
EN
In this paper, a robust decision rule based on regression model and dedicated to classification of known signal in impulsive noise described by heavy-tailed a-stable distribution, is presented. The simulation results confirmed that this rule gives satisfactory results even for the large impulsiveness noise and/or relatively small signal to noise ratio. Due to the numerical burden associated with regression model the presented method is restricted to the set of linearly independent signals. With this restriction in mind we presented an example of the classification results for FSK signals.
10
Content available remote Data-driven score tests for homoscedastic linear regression model : asymptotic results
Inglot T., Ledwina T.
Probability and Mathematical Statistics
|
2006
|
Vol. 26, Fasc. 1
41--61
EN
We describe and investigate new tests for testing the validity of a semiparametric random-design linear regression model. The tests were introduced in Inglot and Ledwina (2006a, b). We repeat here basic steps of the constructions. The resulting statistics are closely linked to some norms of the appropriate efficient score vector and related quantities. A useful way of deriving the efficient score vector is proposed and discussed. We introduce also a large class of estimators of the efficient score vector and prove that under the null model our constructions are asymptotically distribution free. The proof adopts and exploits some ideas and results developed in the area of semiparametric estimation. We give also the limiting distribution of the test statistics under the null hypothesis. The simulation results contained in Inglot and Ledwina (2006a, b) show the very good performance of the proposed tests.
11
Optymalne strategie obserwacji w detekcji uszkodzeń układów o parametrach rozłożonych
Patan M., Uciński D., Baranowski P.
Pomiary Automatyka Kontrola
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2005
|
R. 51, nr 9 bis
71--73
PL
W pracy przedstawiono problem optymalizacji trajektorii ruchomych czujników pomiarowych w sposób zapewniający maksymalną moc testu weryfikującego prostą hipotezę parametryczną dotyczącą nominalnych wartości parametrów charakteryzujących normalny stan pracy układu o parametrach rozłożonych zdefiniowany w zadanym obszarze przestrzennym. Opracowane podejście polega na sformułowaniu problemu optymalizacji trajektorii ruchu czujników w kategoriach zadania sterowania optymalnego, a następnie jego efektywnym rozwiązaniu w oparciu o istniejące pakiety numeryczne. Zaprezentowano ogólny schemat takiego podejścia prowadzącego do maksymalizacji wiarygodności detekcji oraz dokonano jego weryfikacji w oparciu o przykład numeryczny dotyczący problemu adwekeji-dyfuzji.
EN
The problem under consideration is to determine the optimal strategics of observation taken with movable sensors in such a way as to maximize the power of a simple parametric hypothesis test, which verifies the nominal state of the considered distributed system specified on a given multi-dimensional spatial domain. The optimal trajectiores of sensors movements are determined based on the Ds-optimality criterion defined on the respective Fisher Information Matrix. The proposed approach consists in reformulating the problem of sensor trajectory design as an optimal control one and its effective solution with the use of some existing numerical packages. In this work, a general scheme of such an approach leading to Maximization of the fault detection efficiency in distributed-parameter systems is delineated and tested via computer simulations regarding an advection-diffusion problem.
12
Content available remote Methods of estimation of activity efficiency to increase reliability of products outcome
Lyumkis V.
Eksploatacja i Niezawodność
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2005
|
nr 4
38-40
EN
The paper is devoted to comparative analysis of efficiency of one or another activity carried out with the purpose of the improvement of needed characteristics of products. In mathematical aspect, the problem can be reduced to the task of the hypothesis testing regarding the activity efficiency to increase products reliability after their finishing. The details of consideration are presented for the Weibull distribution under the II type censoring conditions.
13
Content available remote Sketches on dilation probability distributions
Wesołowski J.
Demonstratio Mathematica
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2001
|
Vol. 34, nr 2
385-402
EN
The dilation property allows to define an intriguing family of statistical distributions parameterized by the coefficients of respective dilation equation and the dilation scale. The family includes, except some commonly used probability laws, also a wide range of naturally arising singular distributions, which usually are difficult for statistical analysis. But here due to dilation scheme some progress in developing statistical tools can be expected. The paper describes basic properties of dilation distributions, including an extension of the Kershner-Wintner theorem on infinite Bernoulli convolutions, and indicates possible directions for future studies, including preliminary observations on -tatistical inference.
14
Content available Statistical inference about the median from vague data
Grzegorzewski P.
Control and Cybernetics
|
1998
|
Vol. 27, no 3
447-464
EN
In traditional statistics all parameters of the mathematical model and possible observations should be well defined. Sometimes such assumption appears too rigid for the real-life problems, especially when dealing with imprecise or linguistic data. To relax this rigidity fuzzy methods are incorporated into statistics. This paper is devoted to statistical inference about the population median in the presence of vague data. We propose the notion of fuzzy median. Then we suggest a fuzzy estimator and fuzzy confidence interval for the median. Next we discuss the problem of hypothesis testing concerning the median in the presence of imprecise data. All methods presented are distribution-free.
15
Content available remote Most powerful robust tests or robust most powerful tests
Zieliński Ryszard
Matematyka Stosowana : matematyka dla społeczeństwa
|
1995
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Nr 38
113--117
EN
The most powerful robust test and the robust most powerful test in a simple Gaussian model are constructed and discussed.
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