Wyniki wyszukiwania - BazTech

1

The process capability study by the flange shaft production

Lestyánszka-Škurková Katarína, Pauliková Alena

Quality Production Improvement - QPI

|

2021

|

Vol. 3, Iss. 1

305--313

EN

Ensuring the process0capability currently means the warranty, that produced products will be0in accordance with requirements – from company´s side or from customer´s side. This study focuses on the statistical control of flange shaft proces capability by serial production0in company focused on products for automotive. The flange shaft proces is evaluated by control charts,0specifically by control chart for average and range ([iks z kreską poziomą u góry], R). As the results showed, based on diagram for average and range we are able0to say that the turning process is under the statistical control. Also, we had finished the0reguest for capability of process, where0the indexes of capability process Cpk1 and Cpk2 are higher than the determined value on 1.33 point. The normality of the measured values was verified by histogram. Obtained values are: Cpk1 = 1.645 a Cpk = 1.52. Therefore, we can consider the process as capable.

2

Are the Stieltjes constants irrational ? : Some computer experiments

Maślanka K. D., Wolf M.

Computational Methods in Science and Technology

|

2020

|

Vol. 26, No. 3

77--87

EN

Khnichin’s theorem is a surprising and still relatively little known result. It can be used as a specific criterion for determining whether or not any given number is irrational. In this paper we apply this theorem as well as the Gauss-Kuzmin theorem to several thousand high precision (up to more than 53 000 significant digits) initial Stieltjes constants γn, n = = 0, 1, 2, . . . , 5000 in order to confirm that, as is commonly believed, they are irrational numbers (and even transcendental). We also study the normality of these important constants.

3

Effect of non-fulfillment of assumptions on gage repeatability and reproducibility study evaluation

Klaput Pavel, Vykydal David, Plura Jiří

Quality Production Improvement - QPI

|

2019

|

Vol. 1, Iss. 1

472--478

EN

The evaluation of the measurement system quality has already become an integral part of quality planning activities in both the automotive and metallurgical industries. An important assumption for obtaining the most relia ble results is compliance with the basic assumptions for evaluating the variability of the measurement system. The main goal of this paper is to analyze, how the failure to meet the basic assumptions influences the evaluation of the measurement system's statistical properties. This goal is achieved by performing a detailed analysis of the latest developments in the field of measurement systems analysis aimed at verifying the assumptions of normality and uniformity. The evaluation of the effect of non-fulfillment of both assumptions on the values of the most important statistical properties of the measurement system is performed using simulated data. Suitable graphical tools are used for practical verification of both assumptions.

4

The stapling of material layers process capability study by the production of the product "MULTIAXIAL"

Lestyanszka-Skurkova K.

Production Engineering Archives

|

2015

|

Vol. 6, No. 1

10--13

EN

Ensuring the process capability currently means the warranty, that produced products will be in accordance with requirements - from the company or customer´s side. This study focuses on the statistics control of stapling of material layers process capability by production of the product "multiaxial". The stapling of material layers process is evaluated by control charts, specifically by control charts for average and range(, R). As the results show, on the basis of the diagram for average and range we are able to say that the process is under the statistical control. We had also finished the reguest for capability of process, where the indexes of capability process Cp and Cpk are higher than the determinated value by 1,33 points. The obtained values are: Cp = 1,68 a Cpk = 1,55. X

5

Wartości resztowe w procesie regresji

Ampuła D.

Problemy Techniki Uzbrojenia

|

2015

|

R. 44, z. 133

81--102

PL

W artykule autor we wstępie argumentuje potrzebę przeprowadzenia weryfikacji opracowanego modelu regresji za pomocą analizy wartości resztowych. Na początku scharakteryzowano założenia analizy reszt, zwracając uwagę na własności tych reszt czyli: normalność, stałość wariancji i brak autokorelacji. Do analizy wzięto wyniki badań zapalników artyleryjskich typu MD-7. Scharakteryzowano własność wartości resztowych, która głosi, że reszty modelu mają rozkład normalny. Następnie omówiono sposób wyznaczania autokorelacji wartości resztowych, uwzględniając test Durbina-Watsona, który służy do weryfikacji współczynnika autokorelacji. Ze względu na obszerność artykułu nie analizowano metody mnożników Lagrange'a. Omówiono własność stałości wariancji wartości resztowych, czyli założenie homoscedastyczności składnika losowego. W tym celu przedstawiono wykresy rozrzutu reszt względem wartości przewidywanych. Zaprezentowano sposób określania obserwacji nietypowych w analizie procesu regresji. Przedstawiono graficzną postać interpretacji obserwacji odstających za pomocą wykresu rozrzutu reszt względem reszt usuniętych. Na końcu artykułu przedstawiono zwięzłe wnioski dotyczące wartości resztowych w procesie regresji.

EN

In the introduction of the article the author presents the need of verifying a developed regress model by using the analysis of residuum values. On the beginning the presumptions of the residuum analysis are characterized, paying the attention to properties of these residuum i.e.: normality, constancy of variance and lack of autocorrelation. Tests results of artillery fuses type MD-7 were taken to analysis. A property of residuum values showing that residuum of a model have a normal distribution was characterized. Then a way of determining the autocorrelation of residuum values was described, taking into account Durbin-Watson's test, which is used to verify the autocorrelation coefficient. Due to the extensiveness of the article, the method of Lagrange multipliers is not analyzed. A property of variance residuum values constancy i.e. presumption on homoscedasticity of random component is described. The residuum scatter diagrams in relation to forecast values are presented to prove it. A way defining atypical observations in the analysis of regress process was outlined. A graphic figure of interpretation for atypical observations by using residuum scatter diagram in relation to deleted residuum is discussed. Concise conclusions relating to the residuum values in the regress process are presented at the end of the article.

6

Sequential optimization for semilinear divergent hyperbolic equation with a boundary control and state inequality constraint

Gavrilov V. S., Sumin M. I.

Control and Cybernetics

|

2014

|

Vol. 43, no. 2

183--226

EN

An optimal control problem with a state constraint of inequality type and with dynamics described by a semilinear hyperbolic equation in divergence form with the non-homogeneous boundary condition of the third kind is considered. The state constraint contains a functional parameter that belongs to the class of continuous functions and occurs as an additive term. We study the properties of solutions of linear hyperbolic equations in divergence form with measures in the original data and compute the first variations of functionals on the basis of a so-called two-parameter needle variation of controls. We consider the necessary conditions for minimizing sequences in an optimal control problem with a pointwise in time state constraint of inequality type and with dynamics described by a semilinear hyperbolic equation in divergence form with the non-homogeneous boundary condition of the third kind. For the parametric optimization problem, we also consider regularity and normality conditions stipulated by the differential properties of its value function.

7

Wstępna analiza danych z przepływomierza wody uzdatnionej w gminnej stacji uzdatniania wody

Chorzępa R., Cieślak R.

Zeszyty Naukowe Politechniki Rzeszowskiej. Elektrotechnika

|

2013

|

z. 33 [289]

69--78

PL

Ciągły rozwój cywilizacji powoduje nieustanne zwiększanie zagrożeń dla otaczającego środowiska naturalnego. Jednocześnie, zauważa się nieustanne rozwijanie działów nauki związanych z ochroną środowiska i doprowadzaniem go do jak najlepszego stanu. Idea zrównoważonego rozwoju zakłada, że cywilizacja osiągnęła poziom dobrobytu możliwy do utrzymania, pod warunkiem odpowiedniego gospodarowania. Model takiej gospodarki zakłada odpowiednio i świadomie ukształtowane relacje pomiędzy wzrostem gospodarczym a troszczenie się środowisko. W celu utrzymania środowiska naturalnego w stanie nienaruszonym obiekty inżynierskie związane z nim muszą spełniać bardzo surowe wymagania dotyczące automatyki i sterowania. Prawidłowe sterowanie obiektami służącymi ochronie naturalnego środowiska (np. oczyszczalniami ścieków, stacjami uzdatniania wody) nie jest możliwe bez zaawansowanych układów pomiarowych mierzących poszczególne parametry procesów technologicznych. Artykuł przedstawia metody analizy danych z przepływomierza wody uzdatnionej z gminnej stacji uzdatniania wody (SUW). Każda tego typu stacja uzdatniania swoją wydajność produkcji musi dostosować do aktualnego zapotrzebowania na wodę przez jej konsumentów. Analiza tego zapotrzebowania stanowi problem dla układów sterowania SUW z powodu bardzo dużej nierównomierności zapotrzebowania. Istnieją okresy dobowe, gdzie zapotrzebowanie wzrasta gwałtownie, są też takie gdzie jest minimalne. Dodatkowo układ sterowania musi odrzucić wszelkie zakłócenia w torze pomiarowym oraz przetwarzania sygnału. Autorzy podjęli próbę zbadania okresowości, stacjonarności i normalności sygnału stochastycznego przepływu wody uzdatnionej w wybranych okresach. Przeanalizowano wyniki i zaproponowano na ich podstawie sprawne sterowanie SUW.

EN

The continuous evolution of civilization causes increase the risks of natural environment. Simultaneously, notice to be continually progress environmental science connected with protection of environment, and bringing him to the best state. The idea of balanced evolution implies that civilization has reached level of prosperity tenable, provided appropriate management. This model economic assumes suitably and consciously shaped relationship between economic growth, and care about environment. In destination keeping natural environment intact, engineering objects must fulfill strict requirements for automation and control. Proper control object for the protection natural environment (on example: sewage treatment plants, water treatment plants) is not possible without the advanced measurement systems measure various parameters of technological process. This article present methods analysis of data from the raw water flow meter from local Water Treatment Plant (WTP). Every such treatment plant their productivity must to adapt to the current water demand by the consumers. The analyses of this demand is a problem to control systems WTP due to the large diversity of demand. There are daily periods where demand is increasing rapidly, there are also those where it is minimal. The authors have attempted to examine the periodicity, stationarity and the normality of the flow of the treated water during certain time periods. We analyzed the results and proposed effective control of water treatment plants.

8

Using the Shewhart control charts by process control

Lestyanszka-Skurkova K.

Production Engineering Archives

|

2013

|

Vol. 1, No. 1

29--31

EN

This article deals with the statistics pursing the process capability of turning in screws production in RIBE Slovakia, k.s. In technical practice, an important group of statistic methods is formed by analyzing qualification of measures, production equipment and qualification of process. By the term “process qualification“ we mean the ability of the process to observe required technical parameters by required value and tolerance limits. Findings of the process capability can be isolated in the estimate process capability (before starting the production) and permanent process capability. Also, we have finished the quest for the process capability where the indexes Cp and Cpk are bigger than the determined value of 1.33 points.

9

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

|

2012

|

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.

10

Revealed Preference, Congruence and Rationality: A Fuzzy Approach

Georgescu I.

Fundamenta Informaticae

|

2005

|

Vol. 65, nr 4

307--328

EN

In a previous paper connections between the congruence axioms WFCA, SFCA and the revealed preference axioms WAFRP, SAFRP for fuzzy choice functions whose domain contains the characteristic functions of pairs and of triples of alternatives have been studied. The first objective of this paper is to establish such connections for the case of arbitrary fuzzy choice functions. We introduce the new revealed preference axioms WAFRP°, SAFRP°, HAFRP and we prove two main theorems: 1. The axioms WFCA and WAFRP° are equivalent; 2. The axioms SFCA and HAFRP are equivalent. Our second objective is to define G-rational, M-rational, G-normal and M-normal fuzzy choice functions and to investigate some of their properties. The notions and the results are formulated in terms of the residuum of the Gödel t-norm and the proofs use the residuated lattice structure of the interval [0, 1].

11

An eigenvalue problem for linear Hamiltonian dynamic systems

Bohner M., Hilscher R.

Fasciculi Mathematici

|

2005

|

Nr 35

35-49

EN

In this paper we consider eigenvalue problems on time scales involving linear Hainiltonian dynamic systems. We give conditions that ensure that the eigenvalues of the problem are isolated and bounded below. The presented results are applicable also to Sturm-Liouville dynamic equations of higher order, and further special cases of our systems are linear Hamiltonian differ ential systems as well as linear Hamiltonian difference systems.

12

Differential polynomials and normality

Lahiri I., Dewan S.

Demonstratio Mathematica

|

2005

|

Vol. 38, nr 3

579--589

EN

We prove some normality criteria for a family of meromorphic functions which improve and suppliment some earlier results.

13

A Set-Theoretic Framework for Component Composition

Moschoyiannis S., Shields M.W.

Fundamenta Informaticae

|

2004

|

Vol. 59, nr 4

373--396

EN

Modern software systems become increasingly complex as they are expected to support a large variety of different functions. We need to create more software in a shorter time, and without compromising the quality of the software. In order to build such systems efficiently, a compositional approach is required. This entails some formal technique for analysis and reasoning on local component properties as well as on properties of the composite. In this paper, we present a mathematical framework for the composition of software components, at a semantic modelling level. We describe a mathematical concept of a component and identify properties that ensure its potential behaviour can be captured. Based on that, we give a formal definition of composition and examine its effect on the individual components. We argue that properties of the individual components can, under certain conditions, be preserved in the composite. The proposed framework can be used for guiding the composition of components as it advocates formal reasoning about the composite before the actual composition takes place.

14

Higher separation axioms in generalized closure spaces

Stadler B. M. R., Stadler P. F.

Annales Societatis Mathematicae Polonae. Seria 1: Commentationes Mathematicae

|

2003

|

[Z] 43(2)

257-273

EN

The hierarchy of separation axioms that is familiar from topological spaces generalizes to spaces with an isotone and expansive closure function. Neither additivity nor idempotence of the closure function must be assumed.

15

Optimal control of semilinear elliptic equation with state constraint : maximum principle for minimizing sequence, regularity, normality, sensitivity

Sumin M.

Control and Cybernetics

|

2000

|

Vol. 29, no 2

449-472

EN

This article deals with state constrained optimal control problem for semilinear elliptic equation in a domain Omega. The state constraint is lumped on the compactum X contained in/implied by Omega n and contains a functional parameter q in C(X ). It is shown that any minimizing approximate solution (m.a.s.) in the sense of J. Warga satisfies the pointwise maximum principle (the maximum principle for m.a.s.) if the problem is meaningful, i.e., the value of the problem is finite. It is also shown that a condition of Slater's type is sufficient for the normality in the so-called "linear-convex" problem, and the normality of the problem for some fixed value of the parameter q in C(X ) implies the Lipschitz continuity of its value function in a neighborhood of q. The paper contains illustrative examples.

16

The generalization of the Kac-Bernstein Theorem

Quine M. P., Seneta E.

Probability and Mathematical Statistics

|

1999

|

Vol. 19, Fasc. 2

441--452

EN

The Skitovich-Darmois Theorem of the early 1950's establishes the normality of independent X1, X2,…, Xn from the independence of two linear forms in these random variables. Existing proofs generally rely on the theorems of Marcinkiewicz and Cramér, which are based on analytic function theory. We present a self-contained real-variable proof of the essence of this theorem viewed as a generalization of the case n = 2, which is generally called Bernstein's Theorem, and also adapt an early little known argument of Kac to provide a direct simple proof when n = 2. A large bibliography is provided.