Electrical energy metering: Some challenges of the European Directive on Measuring Instruments (MID)

The introduction of static electric energy meter together with voltage and current distortions in the electric networks are revolutionizing the measurement of the electrical energy. Several questions and studies are proposed in the scientific literature concerning with metrological and reliability aspects of the actual electrical energy measurement. The European Directive on Measuring Instruments (MID) represents a different spin on setting the performance and safety requirements for those meters. The International Organization of Legal Metrology (OIML) has published the document D11 discussing recommendations for legislation to meet the MID. An OIML technical committee is drafting the recommendation (IR46) that would give regulatory bodies an easily-adoptable set of requirements and tests to meet the requirements of the MID. With the introduction of the MID directive, the actual discussion involves aspects as the metrological characterization of the meters. The paper proposes an analysis of the test settings imposed by the actual MID-harmonized standards, regarding the electric energy metering. The aim is to check the presence of degree of freedom in the test settings that could compromise both result reliability and the compliance/non-compliance of a given apparatus.     

Accurate neural model identification of measurement devices

A neural approach to modeling measurement devices is presented. This approach allows the usual components of a measurement apparatus (transducers, filters, amplifiers, analog-to-digital converters, etc.) to be easily modeled by means of suitably trained artificial neural networks. Two applications regarding analog and mixed analog/digital devices are reported, highlighting the peculiarity of this approach and the accuracy that can be obtained.     

Determinants of consensus estimates: Attribution, salience, and representativeness.

Five experiments examined the effects of attribution, salience, and representativeness of a target person's behavior on consensus bias—the tendency to generalize from the target's behavior to the behavior of the group. Ss were 762 undergraduates. Exp I showed that actors and observers induced to make a situational attribution for a behavior perceived this behavior as more common than did those induced to make a dispositional attribution. Exps II and III showed that observers perceived salient behavior as more common in the group than nonsalient behavior. Exps IV and V showed that observers were more likely to generalize from the behavior of a representative target than from the behavior of a nonrepresentative target. It is concluded that attributes of the target's behavior exercise strong influence on consensus estimates. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A neural network approach for identification and fault diagnosis ondynamic systems

The possibilities offered by neural networks for system identification and fault diagnosis problems in dynamic systems are investigated. In particular, an original “neural” procedure is illustrated: its sensitivity and response time enable it to be used in on-line fault diagnosis applications. Some examples are also reported. Even though they pertain to a simple linear dynamic system, these examples highlight the general applicability and advantages of a neural approach     

Dyad rapport and the accuracy of its judgment across situations: A lens model analysis.

Ecology of rapport and its perception within 2 contexts (i.e., adversarial and cooperative) were examined from a Brunswikian perspective. A lens model analysis determined (a) which observable cues were indicative of rapport, (b) whether observer judgments covaried with such cues, and (c) whether observers could assess accurately the rapport between opposite-sex interactants. Whereas the manifestation of rapport was context specific, judgment policies used by observers were not. Rapport judgments were driven by target expressivity regardless of social context. Results suggest an "expressivity halo" in behavioral stream judgments that is analogous to the physical attractiveness halo found in judgments made from still photos. Finally, social perception accuracy was higher in the cooperative context where rapport was more strongly associated with target expressivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synchrony, pseudosynchrony, and dissynchrony: Measuring the entrainment process in mother-infant interactions.

We examined a new method for studying synchrony (i.e., the coordination of movement between individuals in social interactions) in two studies. Raters viewed video clips of interactions and judged the level of synchrony occurring between a mother and a 14-month-old child. Some of the video clips were genuine interactions, but most were pseudointeractions artificially constructed from the genuine interactions via split-screen editing techniques. For mothers interacting with their own children, genuine synchrony was significantly higher than pseudosynchrony, a difference that increased with time. When mothers interacted with an unfamiliar child, however, genuine synchrony was not higher than pseudosynchrony. In fact, mothers with unfamiliar children showed a state of dissynchrony (levels of genuine synchrony significantly lower than levels of pseudosynchrony). Our results suggest that synchrony can be reliably rated, thus allowing future investigations to include such measurements when studying social interaction processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement problems arising from the use of a recursive algorithmfor model identification of electrical systems

The use of parameter estimation techniques in practical applications requires accurate analysis of the associated measurement and computation problems. With reference to an already proposed model identification procedure, the authors deal with the experimental tests carried out in order to highlight problems and to find the most appropriate solutions. In particular, a synchronization method is described, and some suggestions concerning the optimal working conditions of all the necessary devices are reported     

Characterization of an eddy-current-based system for nondestructivetesting

A low-cost probe for nondestructive testing of conductive materials was set up and tested. It is based on the measurement of the magnetic field produced by eddy currents (ECs) and perturbed by the presence of cracks. The magnetic sensor used, characterized by the authors in a previous work, gives an output that, suitably processed, allow both the amplitude and phase of the magnetic field to be measured. The preliminary tests reported confirm the suitability of the proposed probe for detecting cracks and correctly identifying their direction and depths     

On-line fault detection and diagnosis obtained by implementingneural algorithms on a digital signal processor

A measurement instrument for on-line fault detection and diagnosis is proposed. It is based on the implementation of a neural network algorithm on a processor specialized in digital signal processing and provided with suitable data acquisition and generation units. Two specific implementations are detailed. The former uses the neural-network to simulate on-line the correct system behavior, thus allowing the fault detection to be achieved by comparing the neural network output with the measured one. The latter uses the neural network to classify on-line the system as correct or faulty, thus allowing the fault detection and diagnosis to be achieved simultaneously. These two implementations are applied to detect on-line and diagnose faults on a real system in order to point out different fields of application and to highlight the performance of the measurement apparatus