Advanced electronic control systems for electric vehicles
The characteristics and relative advantages of several types of electric vehicle control systems are discussed. An advanced electronic control system for a separately excited dc motor is described. Performance characteristics of an electric vehicle using this control are discussed and recommendations for future systems are given.
Modulating Inverter System for Variable-Speed Induction Motor Drive (GM Electrovair II)
The induction motor control system of the battery- powered Electrovair II, where a thyristor (controlled rectifier) modulating inverter supplies the three-phase variable frequency and modulates the voltage level as required by the induction motor is described. Electrovair I, which preceded Electrovair II, used separate power circuits to perform the functions of voltage-level control and frequency generation.
Inferring Learning Strategies from Students ’ Errors
Student models in an Intelligent Tutoring System (ITS) aim at representing both correct and incorrect knowledge of the student in a particular domain of learning. This data serves as the basis upon which the Tutor can dispense remedial feedback. This paper presents a framework in which learners’ errors are diagnosed, classified and linked to cognitive processes associated with learning. The cognitive processes we identify are those of generalization, misattribution and ignorance. Our system applies to the domain of Second Language Acquisition and our approach uses Chomsky’s linguistic theory of Principles and Parameters. We particularly concentrate on the acquisition of the Phrase Structure component.