CONTENTS & ABSTRACTS
In English. Summaries in Estonian
Proceedings of theEstonian Academy of Sciences.
Engineering
Volume 8 No. 1March 2002
Techniquesof combination of metamodel extensions; 3–17
Alar Raabe
Abstract. Extensions to the genericanalysis and design metamodels (for example, UML meta-models) are needed tosupport an effective analysis and design process. Extended analysis meta-modelsthat embody domain knowledge, and extended design metamodels which embodyarchitecture-specific knowledge, can be used in software engineering as aguiding framework. Therefore it is necessary to combine several metamodelextensions. In the article solutions for combining several metamodel extensionsand for the interoperability of metamodel extensions are presented. We alsodiscuss how model transformations can use metamodel extensions.
Key words: metamodelling,metamodels, metamodel extensions, UML.
Ontechnical management of large power transmission networks; 18–37
Taivo Kangilaski
Abstract. This article considers problems which arise by technicalmanagement of large transmission networks and describes a technicalsoftware-related management system “Event Navigator”, developed at EestiEnergia AS.
Key words: transmission network, technical management, software.
Formationof microstructure of spray-fused powder coatings; 38–51
Priit Kulu, Toomas Pihl, Kristi Tammjärv, andPetri Vuoristo
Abstract. Thepaper describes a NiCrSiB self-fluxing alloys based system, containingparticles of tungsten carbide or those of WC-Co hardmetal from the usedhardmetal as hard phase, deposited by the spray and fusion processes. Flame andlaser spray fusions were used as coating technologies. The study focuses onpowder composition, hard phase grain size, processes of deposition, the effectof the composition and process on the formation of the coating structure, andon the evaluation of wear resistance of coatings. We discuss the dependence ofthe wear resistance of spray-fused coatings on their structure and proposestructure criteria for coating selection. The “double cemented” matrixstructure of self-fluxing NiCrSiB based coatings, which contain WC-Coparticles, was found optimal in impact erosion wear conditions. The paper alsodiscusses the cost-effectiveness of coatings in application areas that aresensitive to the cost and which prefer composite coatings based on low costrecycled materials.
Key words: thermal spray, flame spray and fusion, laser spray and fusion,composite coatings, impact erosion, wear.
Identificationof the wheelbase of road vehicles from wheel speed signals;52–57
Péter Frank and AnsgarFries
Abstract. Electronicallycontrolled brake systems are nowadays widely used in road vehicles. The controlsystems consist of sensors, actuators, and of the electronic control unit. Toreduce the number of system components is a permanent market need. Thereforethe intelligence of the control software should be improved. One direction ofimprovement is the implementation of adaptive algorithms. The latter allow torenounce some pre-programmed parameters. The paper presents a simple method forthe identification of the wheelbase of road vehicles by evaluating the wheelspeed signals only. The method uses the correlation between noisy speed signalsof wheels running on the same road track one after another over a bump.Measurements carried out on heavy trucks show the practical value of themethod.
Key words: electronically controlled brake system, road excitation, parameteridentification, correlation.
IN MEMORIAM
Boris Tamm; 58–59
Instructions to authors; 60–62
Copyright Transfer Agreement; 63
