We outline a research proposal whose overall goal is to contribute to the definition of a formal semantics for UML, and indeed visual behavioural modelling languages in general. Specifically, we aim to validate the three-layer semantic architecture, used as a way of explaining the behavioural semantics of UML. The validation includes a definition of the semantics of UML actions and activities, ...

The averaged switch modeling technique unifies the modeling of PWM and resonant dc-dc converters, low-harmonic rectifiers, and inverters in a simple manner. This technique is briefly reviewed, and recent results in modeling current-programmed dc-dc converters, integrated single-phase low-harmonic rectifier-regulators, and single-switch three-phase lowharmonic rectifiers are described. A circuit...

Selecting the proper primary variables is a critical step in efficiently modeling the highly nonlinear problem of multiphase subsurface flow in a heterogeneous porous-fractured media. Current simulation and ground modeling techniques consist of (1) spatial discretization of mass and/or heat conservation equations using finite difference or finite element methods; (2) fully implicit time discret...

This paper presents a control for a three phase three-level neutral point clamped inverter (NPC) for grid connected photovoltaic (PV) system. The maximum power point tracking (MPPT) is capable of extracting maximum power from the photovoltaic (PV) array connected to each DC link voltage level. The MPPT algorithm is solved by Perturb&Observe method. The MPPT system is integrated with the DC-link...

fermentation is an important process for black tea production. during this process, by exposure of substrate to enzymes and the underlying oxidation reactions, quality determining factors of tea is produced. it is known that the exogenous application of cell-wall degrading enzymes leads to the increased production of these compounds through enhancement of enzyme-substrate interactions. pectinas...

The objective is to supply a three phase motors from a single phase AC mains. It is common to have only a single phase power grid in residential, commercial, manufacturing and mainly in rural areas, while adjustable speed drives may require a three phase power grid. Hence we need to convert from single phase to three phase supply to operate the drive system. Parallel converters can be used to i...