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1
Content available Evaluation of the Cause and Consequences of Defects in Cast Metal-Ceramic Composite Foams
Popielarski P., Sika R., Czarnecka-Komorowska D., Szymański P., Rogalewicz M., Gawdzińska K.
Archives of Foundry Engineering
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2021
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Vol. 21, iss. 1
81--88
EN
In this research, the quality of manufactured cast metal-ceramic foams (manufactured using blowing gas) was tested. The causes responsible for defect formation in the composite foams and their consequences were analyzed using the FMEA (Failure Mode and Effects Analysis) method, which is a useful tool for minimizing losses caused by low product quality. This method involves analytically determining correlations between the cause and consequences of potential product defects, and it takes into account the criticality factor (risk). The FMEA analysis showed that pore breaks were the most "critical defect" (with the highest number of effects on the product, the Risk Priority Number, affecting the quality of the composite foam). The second most critical defect was discontinuities in the foam frame structure. Destruction or damage to the foam structure (although very rare) deprived the composite foam of its primary function, which is to reinforce the product. The third most critical defect was non-uniform foam pore size.
2
Content available Open Atlas of Defects as a Supporting Knowledge Base for Cast Iron Defects Analysis
Sika R., Rogalewicz M., Kroma A., Ignaszak Z.
Archives of Foundry Engineering
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2020
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Vol. 20, iss. 1
55--60
EN
A significant development of the foundry industry contributes to the creation of high reliability and operational strength castings so that they meet specific standards in accordance with customers’ needs. This technology, however, is inseparably connected with casting defects in finished products. Cast products are subject to various defects which are considered acceptable or not, which is conditioned by the alloy chemical composition and strength characteristics, that is, generally – qualities to be agreed between the foundry and the customer. It is the latter that led the authors to research on designing a tool enabling the most reliable possible assessment of the emerging casting defects, which after proper consultations can be repaired and the casting – sold. The paper presents an original tool named the Open Atlas of Defects (OAD), developed for the last few years to support the evaluation of cast iron defects using Non-Destructive Testing (NDT) casting defects analysis tools (DCC card – Demerit Control Chart, Pareto-Lorenz analysis and ABC analysis). The OAD tool structure was presented as an integral part of the original system module for acquisition and data mining (A&DM) in conjunction with the possibilities of using selected tools for defect analysis support on the example of cast iron casting.
3
Content available Contribution to the Assessment of the Data Acquisition Effectiveness in the Aspect of Gas Porosity Defects Prediction in Ductile Cast Iron Castings
Ignaszak Z., Sika R., Rogalewicz M.
Archives of Foundry Engineering
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2018
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Vol. 18, iss. 1
35--40
EN
The article presents an example of analysis of the influence of selected parameters deriving from data acquisition in foundries on the occurrence of Gas porosity defects (detected by Visual testing) in castings of ductile cast iron. The possibilities as well as related effectiveness of prediction of this kind of defects were assessed. The need to rationally limit the number of possible parameters affecting this kind of porosity was indicated. Authors also benefited from expert group's expertise in evaluating possible causes associated with the creation of the aforementioned defect. A ranking of these parameters was created and their impact on the occurrence of the defect was determined. The classic statistical tools were used. The possibility of unexpected links between parameters in case of uncritical use of these typical statistical tools was indicated. It was emphasized also that the acquisition realized in production conditions must be subject to a specific procedure ordering chronology and frequency of data measurements as well improving the casting quality control. Failure to meet these conditions will significantly affect the difficulties in implementing and correcting analysis results, from which INput/OUTput data is expected to be the basis for modelling for quality control.
4
Content available Wspomaganie decyzji zakupowych w branży spawalniczej za pomocą metody K-średnich
Rogalewicz M., Kujawińska A.
Zeszyty Naukowe Politechniki Poznańskiej. Organizacja i Zarządzanie
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2016
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Nr 70
203--214
PL
Podejmowanie decyzji w przedsiębiorstwie wiąże się często z wyborem najlepszego rozwiązania na podstawie wielu kryteriów opisujących analizowany problem. Z tego punktu widzenia można go nazwać wielokryterialnym problemem decyzyjnym. W artykule przedstawiono zastosowanie jednej z metod wspomagania decyzji – analizy skupień metodą k-średnich – w doborze materiałów dodatkowych do procesu spawania metodą SAW. Dokonano podziału na skupienia, uwzględniając dwa kryteria doboru ich początkowych centrów, porównano oba warianty, a na końcu scharakteryzowano szczegółowo grupy wyodrębnione za pomocą jednego z nich. Wybrane podejście do analizy skupień okazało się przydatne we wspomaganiu decyzji dotyczących zakupów w branży spawalniczej.
EN
Decision-making in enterprises is often connected with selecting the best solution on the basis of many criteria describing the analyzed problem. From this point of view, it can be called a multi–criterial decision–making problem. The article presents the use of a chosen clustering method – the k-means method – in the selection of materials for the SAW method process. Clusters were divided into two, based on the two different ways of choosing their initial centers. The two options were compared, and finally the clusters created on the basis of the chosen division were characterized in detail. The selected approach proved useful as decision-making support for purchasing materials in the welding industry.
5
Content available Methodologies of knowledge discovery from data and data mining methods in mechanical engineering
Rogalewicz M., Sika R.
Management and Production Engineering Review
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2016
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Vol. 7, No. 4
97--108
EN
The paper contains a review of methodologies of a process of knowledge discovery from data and methods of data exploration (Data Mining), which are the most frequently used in mechanical engineering. The methodologies contain various scenarios of data exploring, while DM methods are used in their scope. The paper shows premises for use of DM methods in industry, as well as their advantages and disadvantages. Development of methodologies of knowledge discovery from data is also presented, along with a classification of the most widespread Data Mining methods, divided by type of realized tasks. The paper is summarized by presentation of selected Data Mining applications in mechanical engineering.
6
Content available Application of expectation maximization method for purchase decision-making support in welding branch
Kujawińska A., Rogalewicz M., Diering M.
Management and Production Engineering Review
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2016
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Vol. 7, No. 2
29--33
EN
The article presents a study of applying the proposed method of cluster analysis to support purchasing decisions in the welding industry. The authors analyze the usefulness of the non-hierarchical method, Expectation Maximization (EM), in the selection of material (212 combinations of flux and wire melt) for the SAW (Submerged Arc Welding) method process. The proposed approach to cluster analysis is proved as useful in supporting purchase decisions.
7
Content available Nieskuteczność kontroli końcowej przyczyną niskiej efektywności procesu wytwarzania
Bożek M., Rogalewicz M.
Inżynieria Maszyn
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2013
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R. 18, z. 1
84--96
PL
Artykuł podejmuje problem wpływu niewłaściwie zaplanowanej kontroli jakości na efektywność procesu wytwarzania. Na przykładzie wybranego narzędzia chirurgicznego opisano i wyznaczono wartości wybranych wskaźników skuteczności i efektywności jakościowej procesu oraz skuteczności procesu kontroli. Pokazano, że w niektórych przypadkach umiejscowienie kontroli w końcowym etapie procesu produkcji może prowadzić do drastycznego obniżenia efektywności procesu.
EN
The article deals with the problem of an influence of incorrectly planned quality inspection on the efficiency of the manufacturing process. On the example of chosen surgical instrument, values of chosen quality process efficiency and effectiveness indices and quality inspection effectiveness index were described and computed. It was shown that in some cases placing a quality inspection at the end of production process can lead to a drastic decrease of the process efficiency.
8
Content available Some notes on multivariate statistical process control
Rogalewicz M.
Management and Production Engineering Review
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2012
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Vol. 3, No. 4
80-86
EN
In the article some features of multivariate statistical process control were introduced. Advantages and disadvantages of multivariate control charts (Hotelling charts) - counterpart of traditional Shewhart control charts in multivariate space - were also shown. The author pointed out the advantage of Hotelling charts over traditional ones in some situations. The main part of the paper is a multivariate surveillance procedure based on the division on two stages: Phase I (phase of stabilization) and Phase II (phase of monitoring). After describing some elements of multivariate statistical process control implementation (considered from the methodological point of view) author introduced two most popular control charts used in industrial practice: control charts for individual observations and for means. The article is summarized by some author's conclusions concerning popularity of multivariate surveillance and future directions of his work.
9
Content available Selection of data mining method for multidimensional evaluation of the manufacturing process state
Rogalewicz M., Piłacińska M., Kujawińska A.
Management and Production Engineering Review
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2012
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Vol. 3, No. 2
27-35
EN
The article deals with the issues involved in evaluating the process state on the basis of many measures, including: process parameters, diagnostic signals and events occurring during the process. These measures as well as those measurements traditionally used in the evaluation of process capability, offer a relevant source of information about the manufacturing process and the authors attempted to ascertain the most suitable method, or group of methods, for achieving this. They present the main criteria for the categorization division of the methods of the manufacturing process state evaluation and, from those identified, distinguish the traditional from Data Mining methods. The authors then specify some basic requirements regarding the desired method or group of methods and focus on the classification problem. A division and classification of the methods is made and briefly described. Finally, the authors specify the criteria for their selection of the Data Mining method type as being the most appropriate for the evaluation of the manufacturing process state and, from within this type, offer the most suitable groups of methods. Some directions for further research are discussed at the end of the article.
10
Narzędzia statystycznego sterowania procesami dla krótkich serii produkcyjnych
Kujawińska A., Rogalewicz M.
Zeszyty Naukowe Politechniki Poznańskiej. Budowa Maszyn i Zarządzanie Produkcją
|
2008
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Nr 9
43-53
PL
W artykule omówiono narzędzia statystycznego sterowania procesem dla krótkich serii. Przedstawiono podstawowe problemy związane z krótkimi przebiegami produkcyjnymi i sposoby ich rozwiązania, a także zaprezentowano najczęściej stosowane karty kontrolne: kartę wartości nominalnej x-R, kartę krótkich serii x—R. Zastosowanie tych narzędzi zilustrowano przykładem z produkcji przemysłowej.
EN
The tools of statistical process control for short production runs were presented. Main problems connected with short runs and their solutions were shown as well as the most often used control charts: Nominal x —R Chart and Short Runjc—R. Application of tools mentioned above were illustrated on the base of an example from industry.
11
ProdBalance : narzędzie do bilansowania zdolności produkcyjnych systemu produkcyjnego
Rogalewicz M., Sika R.
Zeszyty Naukowe Politechniki Poznańskiej. Budowa Maszyn i Zarządzanie Produkcją
|
2007
|
Nr 7
95-108
PL
W pracy przedstawiono narzędzie ProdBalance stworzone w programie MicrosoftŽ Excel™ i przeznaczone dla mikroprzedsiębiorstw i małych przedsiębiorstw, mające na celu pomóc im w zbilansowaniu zdolności produkcyjnych. Program umożliwia scharakteryzowanie obrabiarek i zleceń znajdujących się w systemie produkcyjnym i porównanie możliwości produkcyjnych systemu z zapotrzebowaniem; jest intuicyjny i prosty w obsłudze. W pracy przedstawiono algorytm działania narzędzia wraz ze wskazaniem zastosowanych formularzy oraz założenia towarzyszące jego tworzeniu. Zamieszczono także przykład obliczenia zdolności produkcyjnej konkretnego systemu produkcyjnego i najważniejsze wzory, z których korzystano w trakcie tworzenia narzędzia.
EN
In the paper there was shown a tool named ProdBalance made in MicrosoftŽ Excel™ and designed for microenterprises and small enterprises in order to help them with balancing of production capacity. Programme makes possible describing machine tools and orders found in production system and comparing production capacity with demand; it is intuitive and easy to use. In the paper there was shown an algorithm of working of this tool along with pointing used forms and assumptions made during creating it. There were run: an example of computing production capacity of concrete production system and the most important formulas used during making this tool.
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