Decoupling transformation for weakly coupled linear systems

The non-singular transformation that completely decouples a weakly coupled linear system under non-restrictive conditions is defined. The transformation matrices are obtained from two algebraic matrix equations. Algorithms that efficiently generate solutions to these equations are derived. The proposed transformation also completely decouples the corresponding Lyapunov matrix differential equation.     

Basal cell carcinoma stem cells exhibit osteogenic and chondrogenic differentiation potential

Specific cell subpopulations identified as cancer stem cells (CSCs) can be found in basal cell carcinoma (BCC). Generally, CSCs have a marked trans-differentiation potential that could potentially be used in differentiation therapies. However, there are no studies regarding BCC CSCs multipotency. The aim of the study was to analyze the characteristic of CSCs of BCC with emphasis on their differentiation potential upon specific induction. Specific staining and cell morphology were used for differentiation confirmation, along with the expression analysis of osteogenic (ALP, BSP, Runx2, OCN, BMP2), chondrogenic (COL1 and COL2A1), adipogenic (PPAR-γ) and neurogenic (Nestin and MAP2) markers. BCC CSCs differentiated into osteogenic and chondrogenic lineages, as judged by staining and high expression of specific markers (from 2-to 92-fold higher upon induction). Concomitantly with differentiation, the levels of cancer stem cell markers decreased in the cultures. Adipo-differentiation and neuro-differentiation were unsuccessful. In conclusion, BCC CSCs exhibit the capacity to trans-differentiate, a characteristic that may potentially be useful in the development of new strategies for the treatment of aggressive BCCs.     

NUMERICAL ALGORITHM FOR ARCING FAULTS DETECTION AND FAULT DISTANCE CALCULATION ON OVERHEAD LINES

ABSTRACT

In this paper a new numerical algorithm for arcing faults detection and fault distance calculation will be presented. It provides the solution for both the symmetrical and the unsymmetrical faults. The algorithm is based on the line terminal voltages and currents processing. A simple square wave are voltage model is assumed to model the long are in free air in computer simulation and algorithm development. The frequency dependence of line parameters is taken into account. A series of computer simulated and laboratory tests have shown that the new algorithm can be utilized in transmission system practice.     

Combining Prior Symbolic Knowledge and Constructive Neural Network Learning

The concepts of knowledge-based systems and machine learning are combined by integrating an expert system and a constructive neural networks learning algorithm. Two approaches are explored: embedding the expert system directly and converting the expert system rule base into a neural network. This initial system is then extended by constructively learning additional hidden units in a problem-specific manner. Experiments performed indicate that generalization of a combined system surpasses that of each system individually.     

AN EFFICIENT METHOD OF SYSTEM MATRIX FORMULATION FOR MULTIMACHINE POWER SYSTEMS WITH STATOR AND DAMPING WINDINGS TRANSIENTS INCLUDED

ABSTRACT

In this paper an efficient method of system matrix formulation for multimachine power systems with stator and damping windings transients included is presented. A singular perturbation analysis of the synchronous machine equations in the (d, q) reference frame reveals that reduced order linearized model of multi-machine power systems can be derived systematically from the fundamental machine equations. The application of the developed model in Small Signal (Dynamic) Stability Study of the power system of Serbia is given. The valuable discussion on the practical implementation of the models and dependence on the exciter type is given, too.     

The quality of plain and supplemented kefir from goat's and cow's milk

Goat's or cow's milk was fortified with 2 g/100 g skimmed milk powder (SMP), whey protein concentrate (WPC) or inulin. All the milks were fermented with kefir grains at 25°C for 19 h and stored for 10 days at 5°C. All the kefir samples were analysed on the 1st, 5th and 10th day of storage. The acidity level remained very stable in all the samples during the storage period. Goat's samples have significantly lower viscosity and slightly lower sensory profiles, mostly due to softer consistency. Concentration of ethanol was low, regardless of milk type used, especially for control samples.