Wyniki wyszukiwania - BazTech

1

Network knowledge bases for technical diagnostics

Cholewa W.

Scientific Problems of Machines Operation and Maintenance

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2011

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Vol. 46, nr 1

7-13

EN

The paper briefly discusses the application of a multilayer statement network as a qualitative model of a diagnosed object and a model of a diagnostic knowledge base. The reasoning process in statement networks is based on searching for an equilibrium state of the network.

PL

Omówiono zwięźle możliwość zastosowania wielowarstwowej sieci stwierdzeń jako jakościowego modelu diagnozowanego obiektu oraz jako modelu diagnostycznej bazy wiedzy. Wyjaśniono, że proces wnioskowania w sieciach stwierdzeń polega na poszukiwaniu stanu równowagi sieci.

2

Platforma do budowania sieci stwierdzeń

Cholewa W., Chrzanowski P., Rogala T., Amarowicz M.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 9

1079-1082

PL

W niniejszym artykule przedstawiono wyniki badań związanych z zastosowaniem metod i technik sztucznej inteligencji w obszarze diagnostyki technicznej. Szczególną uwagę zwrócono na możliwość budowania systemów doradczych opartych na wielowarstwowych sieciach stwierdzeń. Przedstawiono ogólną koncepcję platformy do budowania sieci stwierdzeń. Nakreślono plan prac związanych z rozwojem platformy, który umożliwi stosowanie różnego typu sieci w ramach jednego modelu oraz integrację z innymi systemami.

EN

This paper deals with the results of studies relevant to the methods and techniques of artificial intelligence in the field of technical diagnostics. At the beginning, the basic concepts, such as the statement and statement network, are described. Then, the concept of a multilayer statement network (Fig. 1) which is generalization of a single-layer statement network is presented. Special attention is paid to possibility of using the multilayer statement networks for development of multi-scale statement networks. Next, the general concept of a platform for development of the multilayer statement network and description of the main classes of objects resulting from using the platform are given. The choice of R environment for development of the platform is justified and its advantages are emphasized. The data exchange with other systems using XML format and the file structure is described. The process of construction of the multilayer statement network is discussed based on an example of the two-layer network shown in Fig. 2. The obtained results show the correctness of the platform operation. Finally, the main advantages of platforms, such as possibility of development of multilayer statement networks or commenting of the particular objects are discussed. The schedule of the development of platforms, including e.g. extension of the learning process of the network structure and tuning the network parameters basing on the available data sets or extension-training opportunities to construct multilayer network models with different types of networks on a different layers is also presented.

3

Badania porównawcze wielomodalnych sieci stwierdzeń

Cholewa W., Skupnik D.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 11

1388-1393

PL

Artykuł dotyczy badań porównawczych wielomodalnych sieci stwierdzeń. Przedstawiono definicje sieci stwierdzeń oraz sieci wielomodalnej. Pokazano, że szczególną wersją sieci stwierdzeń może być sieć przekonań lub sieć warunków koniecznych i dostatecznych. Prezentowane sieci wielomodalne zostały opracowane w szkieletowym systemie doradczym MMNET i dotyczą diagnozowania stanu technicznego obiektu stanowiącego fizyczną miniaturyzację instalacji przemysłowej stosowanej, np. w przemyśle chemicznym. Przeprowadzone badania porównawcze pozwoliły określić zalety i wady badanych sieci.

EN

The paper deals with comparative studies of multimodal statement networks. Section 1 contains description of the concept of a multimodal network and a statement. A belief (Bayesian) network as well as a network of necessary and sufficient conditions (exact and approximate) are briefly described in Section 2. Section 3 is the most important part of the paper. It shows that the considered networks can be constructed by means of the MMNET system [4]. Fig. 3 presents the considered technical object which exemplifies a physical miniaturization of an industrial installation used, e.g. in a chemical or food industry. The object operation is illustrated in Fig. 4. It was decided to consider 12 possible technical states of the object including so-called complex states, i.e. the cases when at least 2 elements of the object were faulty. Active diagnostic experiments were conducted in order to obtain sets of data necessary for identification of the examined networks (diagnostic models). Comparison was performed on the basis of the results obtained from the identified models (e.g. Tabs. 2, 3 and 4). In consequence, it was possible to determine advantages and disadvantages of the networks. Tab. 5 shows that comparison. Belief networks are used in many different domains also in technical diagnostics. It seems that multimodal statement networks exemplify an interesting alternative because they have got many advantages especially a possibility of constructing models as a result of integration of independently identified component networks and a possibility of reasoning on the basis of inaccurate and partly contradictory data.

4

Mechanical analogy of statement networks

Cholewa W.

International Journal of Applied Mathematics and Computer Science

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2008

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Vol. 18, no 4

477-486

EN

The paper demonstrates briefly the reasoning capabilities in condition monitoring offered by systems based on statement networks. The usefulness of the networks considered results among others from possibilities of their optimization related to the minimization of contradictions between rules acquired from different knowledge sources. A mechanical analogy of such networks introduces an interpretation of statements as material points that are able to move. Dependencies between statements are considered as approximate necessary and approximate sufficient conditions, which are represented by unilateral constraints imposed on the introduced material points. A model of a dynamic statement network can be obtained out of the network consisting of statements represented by material points with assigned masses, where the inertia of statements may be taken into account. The paper introduces a measure of conditional contradictions of statements, which can be used for monitoring knowledge bases in running expert systems.

5

Sieci stwierdzeń w diagnostyce technicznej

Cholewa W.

Diagnostyka

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2006

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nr 2(38)

121-128

PL

Opisano zwięźle główne klasy systemów bazujących na wiedzy, które mogą być stosowane do wnioskowania w diagnostyce technicznej. Ich szczególne znaczenie jest związane z możliwościami oferowanymi przez systemy stosujące sieci stwierdzeń. Omówiono wybrane zagadnienia związane ze stosowaniem bardzo obiecujących sieci stwierdzeń dynamicznych. Wydaje się, że będą one mogły skutecznie wspomagać między innymi rozwiązywanie zadań diagnostycznych dla obiektów działających w warunkach przejściowych.

EN

Paper discusses shortly main classes of knowledge based systems applied for reasoning in technical diagnostics. Their considerable importance is connected with possibilities delivered by systems basing on statement networks. Selected details related to the application of very promising dynamic statement networks are also discussed. It seems that they can effectively aid solving diagnostic tasks for objects running in transient conditions.