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1
Content available Supporting the Bronze CastingThrough Information Structuring Based on Ontology application
Górny Z., Wilk-Kołodziejczyk D., Smolarek-Grzyb A.
Archives of Foundry Engineering
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2014
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Vol. 14, iss. 1
33--36
EN
A significant part of the knowledge used in the production processes is represented with natural language. Yet, the use of that knowledge in computer-assisted decision-making requires the application of appropriate formal and development tools. An interesting possibility is created by the use of an ontology that is understandable both for humans and for the computer. This paper presents a proposal for structuring the information about the foundry processes, based on the definition of ontology adapted to the physical structure of the ongoing technological operations that make up the process of producing castings.
2
Content available remote Acquisition of technology knowledge from online information sources
Kluska-Nawarecka S., Wilk-Kołodziejczyk D., Dziaduś-Rudnicka J., Smolarek-Grzyb A.
Archives of Foundry Engineering
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2011
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Vol. 11, iss. 3
107-112
EN
The article discusses problems related with the search of information from open sources, particularly on the Internet. Specific area of concern is searching for technical knowledge in the area of metalcasting. The results of ongoing experiments were given, to serve as a basis in identification of the opportunities to improve the process of searching through determination of own research plans.
3
Content available remote Application of evolutionary algorithms to optimize the model parameters of casting cooling process
Kluska-Nawarecka S., Górny Z., Smolarek-Grzyb A.
Archives of Foundry Engineering
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2010
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Vol. 10, iss. 4
89--92
EN
One of the most commonly used methods of numerical simulation is the finite element method (FEM). Its popularity is reflected in the number of tools supporting the preparation of simulation models. However, despite its usefulness, FEM is often very troublesome in use; the problem is the selection of the finite element mesh or shape function. In addition, MES assumes a complete knowledge of the simulated process and of the parameters describing the investigated phenomena, including model geometry, boundary conditions, physical parameters, and mathematical model describing these phenomena. A comparison of the data obtained from physical experiments and simulations indicates an inaccuracy, which may result from the incorrectly chosen shape of element or geometry of the grid. The application of computational intelligence methods, combined with knowledge of the manufacturing technology of metal products, should allow an efficient selection of parameters of the mathematical models and, as a consequence, more precise control of the process of the casting solidification and cooling to ensure the required quality. The designed system has been integrated with the existing simulation environment, which will significantly facilitate the preparation and implementation of calculations of this type. Moreover, the use of a distributed model will significantly reduce the time complexity of calculations, requiring multiple repetition of complex simulations to estimate the quality of the different sets of parameters.
4
Content available Optimization of simulation model parameters for solidification of metals with use of agent-based evolutionary algorithm
Kluska-Nawarecka S., Smolarek-Grzyb A., Byrski A., Wilk-Kołodziejczyk D.
Computer Science
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2008
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Vol. 9
55-66
EN
The finite elements method (FEM) is currently widely used for simulation of thermal processes. However, one of still unresolved problems remains proper selection of mathematical model parameters for these processes. As far as modelling of cooling casts in forms is concerned, particular difficulties appear while estimating values of numerous coefficients such as: heat transport coefficient between metal and form, specific heat, metal and form heat conduction coefficient, metal and form density. Coefficients mentioned above depend not only on materials properties but also on temperature. In the paper the idea of optimalization of simulation method parameters based on adaptive adjustment of curve representing sim­ulation result and result obtained in physical experiment is presented along with the idea of evolutionary and agent-based evolutionary optimization system designed to conduct such optimizations. Preliminary results obtained with use of ABAQUS system available in ACK CYFRONET and software developed at AGH-UST conclude the paper.
PL
Metoda elementów skończonych (MES) znajduje obecnie liczne zastosowania w symulacji procesów cieplnych. Wciąż jednak nierozwiązalny pozostaje problem doboru niektórych współczynników modeli matematycznych tych procesów. Przy modelowaniu stygnięcia odlewów w formie, szczególne trudności powstają przy wyznaczeniu wartości licznych parametrów, np.: współczynnika transportu ciepła pomiędzy metalem a formą, ciepła właściwego, współczynnika przewodnictwa cieplnego metalu i formy, gęstości metalu i formy. Współczynniki te zależą nie tylko od właściwości materiałów, lecz również od temperatury. W artykule zaproponowano metodę optymalizacji wartości parametrów modelu opartą na adaptacyjnym dostosowaniu krzywej stanowiącej wynik symulacji do przebiegu uzyskanego w eksperymencie fizycznym z zastosowaniem algorytmu ewolucyjnego w wersji agentowej. Wstępne wyniki obliczeń zostały zrealizowane przy wykorzystaniu systemu ABAQUS dostępnego w ACK CYFRONET oraz oprogramowania opracowanego przez AGH-UST.
5
Content available remote The logistic of plausible reasoning in the diagnosis of castings defects
Kluska-Nawarecka S., Górny Z., Wilk-Kołodziejczyk D., Smolarek-Grzyb A.
Archives of Metallurgy and Materials
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2007
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Vol. 52, iss. 3
375-380
EN
Quick diagnosis of the cause of crack formation enables preventing the formation of other cracks in the next casting process and enables also, as far as it is possible, a repair of the existing defect. In this task expert systems are a very useful tool. The efficiency of an expert system diagnosis depends on the data entered previously and on the way in which the knowledge is represented. In the article there has been presented the Logic of Plausible Reasoning with the rules of its usage on the example of “crack” fault. Drawing attention to advantages of such an approach in relation to solutions used in existing expert systems.
PL
Szybka diagnostyka przyczyny powstania wady pozwala na nie dopuszczenie do powstania nowych w kolejnym procesie odlewania, oraz jeżeli to możliwe naprawienie powstałej. W procesie takim bardzo pomocne są systemy ekspertowe. Skuteczność ich diagnozy uzależniona jest od informacji wprowadzonych do nich oraz od sposobu reprezentacji tej wiedzy. W pracy podano krótką charakterystykę LPR ilustrując zasady jej wykorzystanie na przykładzie wady „pęknięcie”. Zwracając uwagę na zalety proponowanego podejścia, w stosunku do rozwiązań stosowanych w istniejących systemach ekspertowych.
6
Content available remote Diagnostics of crack formation in castings using the logic of plausible reasoning
Kluska-Nawarecka S., Górny Z., Wilk-Kołodziejczyk D., Smolarek-Grzyb A.
Archives of Materials Science and Engineering
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2007
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Vol. 28, nr 8
479-482
EN
Purpose: Cold cracks are the defect often encountered in castings. Quick diagnosis of the cause of crack formation enables preventing the formation of other cracks in the next casting process and enables also, as far as it is possible, a repair of the existing defect. In this task expert systems are a very useful tool. Design/methodology/approach: Standard of Casting Defects elaborated in Poland, Atlas of Casting Defects elaborated in France, and a Review of Casting Defects elaborated in the Czech Republic. These sources are the knowledge compendium of casting defects. Basing on such information, serving as a defect description, the cause of the defect formation and the way of preventing it have been created as formalisms which enable an inference to be carried out, the aim of which is to establish the cause of the defect. Findings: The use of LPR (the Logic of Plausible Reasoning) in the representation of knowledge about casting defects introduces a new quality, allowing to take into consideration the specific characteristics of this knowledge such as: uncertainty, definitions hierarchy, the possibility of introducing the diagnostics ranking. In consequence, the diagnostic process becomes more flexible and may be better adjusted to the real technological process conditions. Practical implications: The efficiency of an expert system diagnosis depends on the data entered previously and on the way in which the knowledge is represented. Originality/value: In this article various representations of the knowledge have been presented by means of the logic of plausible reasoning.
7
Content available remote Knowledge representation of casting metal defects by means of ontology
Kluska-Nawarecka S., Smolarek-Grzyb A., Wilk-Kołodziejczyk D., Adrian A.
Archives of Foundry Engineering
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2007
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Vol. 7, iss. 3
75-78
EN
The scattered nature of information requires implementation of appropriate tools and system solutions. The conception of decentralized diagnostic system of casting metal defects, in which the methods of concept classification in the form of ontology are used, has been presented in the article. Also, the general rules of ontology creation, model division into modules, the hierarchy of classes and their instances have been introduced. There has been provided an example of ontology construction for casting defects.
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