City University London

About: City University London is a education organization based out in London, United Kingdom. It is known for research contribution in the topics: Population & Health care. The organization has 5735 authors who have published 17285 publications receiving 453290 citations.

Real-time frequency and harmonic evaluation using artificial neural networks

Abstract: With increasing harmonic pollution in the power system, real-time monitoring and analysis of harmonic variations have become important. Because of limitations associated with conventional algorithms, particularly under supply-frequency drift and transient situations, a new approach based on nonlinear least-squares parameter estimation has been proposed as an alternative solution for high-accuracy evaluation. However, the computational demand of the algorithm is very high and it is more appropriate to use Hopfield type feedback neural networks for real-time harmonic evaluation. The proposed neural network implementation determines simultaneously the supply-frequency variation, the fundamental-amplitude/phase variation as well as the harmonics-amplitude/phase variation. The distinctive feature is that the supply-frequency variation is handled separately from the amplitude/phase variations, thus ensuring high computational speed and high convergence rate. Examples by computer simulation are used to demonstrate the effectiveness of the implementation. A set of data taken on site was used as a real application of the system.

The European study of assisted reproduction families: the transition to adolescence

Abstract: BACKGROUND: Findings are presented of the second phase of a European longitudinal study of families created by assisted reproduction. The present investigation reports on data obtained during the child’s transition to adolescence. METHODS: A total of 102 IVF families, 94 donor insemination (DI) families, 102 adoptive families, and 102 families with a naturally conceived child were compared on standardized interview and questionnaire measures of parenting and children’s psychological well-being. RESULTS: The assisted reproduction families were similar to the adoptive and natural conception families for many of the measures of the quality of parent–child relationships. To the extent that differences were found between the assisted reproduction families and the other family types, these reflected mainly more positive functioning among the assisted reproduction families, with the possible exception of the overinvolvement with their children of a small proportion of assisted reproduction mothers and fathers. The assisted reproduction children were functioning well and did not differ from the adoptive or naturally conceived children on any of the measures of psychological adjustment. However, only 8.6% had been told about their genetic origins. CONCLUSIONS: IVF and DI families with an early adolescent child appear to be functioning well.

The Brexit Botnet and User-Generated Hyperpartisan News:

Abstract: In this article, we uncover a network of Twitterbots comprising 13,493 accounts that tweeted the United Kingdom European Union membership referendum, only to disappear from Twitter shortly after the ballot. We compare active users to this set of political bots with respect to temporal tweeting behavior, the size and speed of retweet cascades, and the composition of their retweet cascades (user-to-bot vs. bot-to-bot) to evidence strategies for bot deployment. Our results move forward the analysis of political bots by showing that Twitterbots can be effective at rapidly generating small- to medium-sized cascades; that the retweeted content comprises user-generated hyperpartisan news, which is not strictly fake news, but whose shelf life is remarkably short; and, finally, that a botnet may be organized in specialized tiers or clusters dedicated to replicating either active users or content generated by other bots.