Ontology-based modeling of dynamic ubiquitous computing applications as evolving activity spheres

As the computer disappears in the environments surrounding our activities, the objects therein become augmented with sensors, actuators, processors, memories, wireless communication modules and they can receive, store, process and transmit information. In addition to objects, spaces also undergo a change towards becoming smart and eventually Ambient Intelligence (AmI) spaces. In order to model the way everyday activities are carried out within an AmI environment, we introduce the notion of “activity sphere”. In this paper, we are interested in the ontology-based representation of activity spheres from two different perspectives (as creators and as observers), as well as the modeling and control of the dynamic nature of activity spheres.     

An editing tool that manages device associations in an in-home environment

The forthcoming home environment will comprise numerous computationally enhanced artifacts that are autonomous, but interconnected via an invisible web of network-based services. The approach presented in this paper is to enable end users to make their own applications by linking such artifacts, which are treated as reusable components. A key requirement to achieve this is the availability of editing tools that meet the needs of different classes of users. A tool of this kind designed for end users is presented in this paper, together with the outcome of user evaluation sessions.     

SSR countermeasure impact on system induction-generator effect

Generalized transmission parameter equations are derived for the induction-generator (IG)-effect constraints on a system to which subsynchronous resonance (SSR) countermeasures of the active type are applied to control a torsional instability at a frequency that coincides with or is close to the synchronous complement of the electrical resonance frequency. The presence of the phenomenon under varying transmission topologies is analyzed, for typical system data, in a study carried out for two leading SSR remedial concepts: the dynamic stabilizer and the NGH scheme. IG-control by modulation phase angle in the stabilizer case and by a discrete capacitor discharge in the NGH scheme is postulated and analyzed     

Design and Commissioning of a Friction Welding Machine

An experimental lightweight linear friction welding machine was designed and commissioned. The machine was designed to explore higher frequencies of oscillation (up to 1 kHz) than those commercially available, for a number of different amplitudes of oscillation. During the commissioning stage problems related to rig stiffening were recognized and the operating envelope of the machine was identified. Important friction welding process parameters like stress and temperature are monitored to evaluate process development and weld integrity.     

The near-threshold high R-ratio fatigue crack growth characteristics of SA508 cl III reactor pressure vessel steel

This paper describes the effect of frequency and environment on the near-threshold fatigue crack growth behaviour of SA508 cl III reactor pressure vessel (RPV) steel. The study has shown that in the near-threshold regime microstructure and environment markedly affect fatigue crack growth behaviour. In an aqueous environment, fatigue crack growth behaviour became even more sensitive to microstructure, and the fatigue crack growth rate increased by a factor of four in the case of the 3 Hz test, while that for the 0·3 Hz test was increased by a factor of approximately sixteen. This environmental enhancement manifested itself in the form of intergranular failure. For the 0·3 Hz test the percentage intergranular failure decreased from 18% to <1% with an increase in ΔK level. The transition from microstructure-sensitive to microstructure-insensitive occurs when the cyclic plastic zone size is of the order of the prior austenite grain size.     

The influence of waveform on the fatigue crack growth behaviour of SA508 cl III RPV steel in various environments

This paper describes the effect of waveform, sinusoidal and positive sawtooth, on the fatigue crack growth behaviour of SA508 cl III RPV steel in various environments under ambient conditions. Positive sawtooth waveform consistently gave faster crack growth rates than sine waveform although the amount varied depending on the environment and in some cases frequency. Of the two basic mechanisms suggested for environmentally enhanced crack growth, namely, dissolution controlled and hydrogen induced cracking, the latter can more readily explain the results of the present investigation. The longer period of increasing tensile load for the positive sawtooth resulted in increased hydrogen transport to the region of greatest triaxial stress.     

Photon-number-resolving detection using time-multiplexing

Abstract

Detectors that can resolve photon number are needed in many quantum information technologies. In order to be useful in quantum information processing, such detectors should be simple, easy to use, and be scalable to resolve any number of photons, as the application may require great portability such as in quantum cryptography. Here we describe the construction of a time-multiplexed detector, which uses a pair of standard avalanche photodiodes operated in Geiger mode. The detection technique is analysed theoretically and tested experimentally using a pulsed source of weak coherent light.     

The evolution of objects into hyper-objects: will it be mostly harmless?

Objects may in the future become enhanced with new digital properties and information-communication capabilities, thus turning them into Hyper-Objects. This paper describes an approach towards defining Hyper-Objects, and examines to what extent their advance affects our existing lifestyle patterns.     

Silicon Carbide Varistor Competitiveness in EHV Sfries Capacitor Reinsertion

Developments attained during the last decade in the field of non-linear resistor technolong Save introduced EHV series capacitor fast reinsertion as an attractive application area. The recently evolved Zinc Oxide (ZNO) scheme challenges, in a 500 KV expansion project in Argentina, the older Silicon Carbide (SIC) dual-gap arrangement applied to the current series compensation. A comparative parametric study drawing the relative merits of both concepts is presented for single- and three-phase fault criteria. The economic outlook, derived from the application of proposed reinsertion branch cost functions to the respective varistor energy absorptions, is complemented by the calculation of the associated rotor accelerating power as a measure of system stability. The conclusions drawn are broadened by including the consideration of a hypothetic (closer to the generation) alternative capacitor location.     

Dispositional resistance to change: Measurement equivalence and the link to personal values across 17 nations.

The concept of dispositional resistance to change has been introduced in a series of exploratory and confirmatory analyses through which the validity of the Resistance to Change (RTC) Scale has been established (S. Oreg, 2003). However, the vast majority of participants with whom the scale was validated were from the United States. The purpose of the present work was to examine the meaningfulness of the construct and the validity of the scale across nations. Measurement equivalence analyses of data from 17 countries, representing 13 languages and 4 continents, confirmed the cross-national validity of the scale. Equivalent patterns of relationships between personal values and RTC across samples extend the nomological net of the construct and provide further evidence that dispositional resistance to change holds equivalent meanings across nations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)