A MODEL FOR C-CALCULUS

C-calculus was introduced by the first author as a technique for the analysis of complex hierarchical systems.² It has been further applied as a versatile tool in pattern recognition.^1,3 Our present aim is to exhibit a model for C-calculus, and deal with its convergence and filtering properties.     

SALVAGING THE SPIRIT OF THE METER-MODELS TRADITION: A MODEL OF BELIEF REVISION BY WAY OF AN ABSTRACT IDEALIZATION OF RESPONSE TO INCOMING EVIDENCE DELIVERY DURING THE CONSTRUCTION OF PROOF IN COURT

Conversations occurring in a society of communicating systems can be studied according to a model where the main concept is a theory and exchanges are governed by syntactic, semantic, and pragmatic devices. In the present paper we discuss these issues, focusing on the role played by situations where context marks are meaningful for governing dialogues. We take the case of intelligent tutors, in particular one for logic programming under development, as the application example behind this research. Finally, we stress that the flexibility of interactions depends to a great extent on the ability of knowledge-based systems to face open situations.     

PRELIMINARY CONSIDERATIONS ABOUT THE ADOPTION OF UNCONVENTIONAL MAGNETIC MATERIALS AND STRUCTURES FOR INDUCTION MOTORS

ABSTRACT

The activity carried out and presented in this paper deals with the opportunity of utilizing high quality magnetic materials, such as amorphous, microcristalline or cubic texture materials for the magnetic structure of medium size induction motors.

In order to evaluate the benefits introduced by these materials for reducing the iron losses in a.c. motors, digital preliminary computations have been carried out considering the characteristic of such materials (Induction versus specific losses) and the obtained results for each solution have been compared.

At the present, however, the; above mentioned materials are costly, not easy to handle and to assemble and therefore a practical solution with grain oriented steel in a crossed structure obtained alternating sheets with orthogonal grain orientation, in order to simulate the cubic texture material (i-oriented material) has been proposed.

To verify the obtained theoretical results with the digital computations, a prototype of 20 Hp, 380 V, three phases induction motor with this non conventional magnetic structure has been designed and built. The tests on the prototype to evaluate the iron losses are in good agreement with the digital simulation results.     

MAXIMAL CONSISTENCY,THEORY OF EVIDENCE,AND BAYESIAN CONDITIONING IN THE INVESTIGATIVE DOMAIN

We present the architecture of an Inquiry Support System whose aim is to help a detective or a judge in eliciting a maximally consistent set of beliefs as the most believable piece of knowledge to reason with. This is done by (1) finding incoherence inside and across the various depositions; (2) generating the alternate maximally consistent set of beliefs; (3) estimating the degree of reliability of the various informants; and (4) estimating the degree of credibility of the various evidences. The solution of the case is searched among the various possible plots compatible with the maximally consistent set of beliefs retained by the system as the most believable one.     

PROTEOLYTIC ACTIVITY OF LACTOBACILLUS SAKEI, LACTOBACILLUS FARCIMINIS AND LACTOBACILLUS PLANTARUM ON SARCOPLASMIC PROTEINS OF PORK LEAN

The aim of this study was to assess the proteolytic activity of Lactobacillus sakei (DSM 6333), L. plantarum (B21), and to a lesser extent, L. farciminis (DSM 20184) on meat sarcoplasmic proteins. The protein composition was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and capillary electrophoresis after incubation of meat extract inoculated with bacteria. All strains showed proteolytic activity: a band about 94 kDa disappeared in samples inoculated with L. farciminis and L. plantarum and strongly decreased in those inoculated with L. sakei. The intensity of the bands with a molecular weight between 94 and 38 kDa decreased in all samples. Capillary electrophoresis analysis ascertained the disappearance of the fractions corresponding to 8.64 and 8.66 min retention time in all samples. The bands corresponding to 94 kDa and 38 kDa were, respectively, identified as glycogen phosphorylase muscle isoform and glyceraldehyde 3-phosphate dehydrogenase, by in situ digestion of protein gel bands and peptide map analysis using Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS).     

TEST PROCEDURE FOR VERY HIGH SPEED SPINDLE MOTORS

Abstract

In the last ten years, the new power electronic devices and the new control techniques have allowed to open new application fields for adjustable speed/torque electrical drives. Although the traditional dc drives keep still the market supremacy, the new ac drives have performance really attractive and some additional benefits due to the machine structure and to the maintenance costs. Usually, ac drives use induction or brushless motors and the power amplifiers are driven by variable voltage/frequency in order to obtain variable speed. The authors deal with induction motors fed by non conventional supplies at very high frequency. In order to evaluate the total motor losses and the single items, a test bench with a synchronous machine capable to work up to 2 kHz with sinusoidal output voltage has been set up. As a consequence, an induction motor equivalent circuit with parameters depending on the frequency has been proposed. Today, the empirical procedure is that to use for high frequency applications shelf motors derated of a factor 10 to 20 % in order to keep into account the extra harmonic losses. On the other hand, the authors propose to design ‘ad hoc’ the motors for six-steps continuous operation in order to get about the same efficiency of standard motors. The new proposed motor equivalent circuit together with the test procedure seem to be a practical tool in order to aid the new motor design.     

LOSS ITEMS EVALUATION IN INDUCTION MOTORS FED By SIX-STEP VSI

ABSTRACT

At present time, induction motors are widely supplied from several types of solid-state adjustable voltage-frequency controllers with a wide range of operating features. However, in any case, the motor has to be derated for the harmonic effects due to the non-sinusoidal nature of the supply voltage. The authors propose a simple method based on the no-load and short circuit test in order to get the useful machine parameters to adopt in equivalent circuit model for the losses evaluation. Complete experimental results are reported and the comparison between six-step and sinusoidal supplies are summarized.