Considerations Concerning Matrix Diagram Transformations Associated with Mathematical Model Study of a Three-phase Transformer Journal title: Analele Universitatii "Eftimie Murgu" Resita. Fascicula de Inginerie Authors: Mihaela Poienar, Daniel Ștefan Georgescu, Ovidiu-Magdin Ţanţa, Ilie Niţan, Elena-Daniela Olariu, Dor... Subject(s):