An automatic COLREGs-compliant obstacle avoidance system for an unmanned surface vehicle

Unmanned surface vehicles are becoming increasingly vital tools in a variety of maritime applications. Unfortunately, their usability is severely constrained by the lack of a reliable obstacle detection and avoidance system. In this article, one such experimental platform is proposed, which performs obstacle detection, risk assessment and path planning (avoidance) tasks autonomously in an integrated manner. The detection system is based on a vision-LIDAR (light detection and ranging) system, whereas a heuristic path planner is utilised. A unique property of the path planner is its compliance with the marine collision regulations. It is demonstrated through hardware-in-the-loop simulations that the proposed system can be useful for both uninhabited and manned vessels.

A statistical process control approach for automatic anti-islanding detection using synchrophasors

Anti-islanding protection is becoming increasingly important due to the rapid installation of distributed generation from renewable resources like wind, tidal and wave, solar PV, bio-fuels, as well as from other resources like diesel. Unintentional islanding presents a potential risk for damaging utility plants and equipment connected from the demand side, as well as to public and personnel in utility plants. This paper investigates automatic islanding detection. This is achieved by deploying a statistical process control approach for fault detection with the real-time data acquired through a wide area measurement system, which is based on Phasor Measurement Unit (PMU) technology. In particular, the principal component analysis (PCA) is used to project the data into principal component subspace and residual space, and two statistics are used to detect the occurrence of fault. Then a fault reconstruction method is used to identify the fault and its development over time. The proposed scheme has been used in a real system and the results have confirmed that the proposed method can correctly identify the fault and islanding site.

Who was Andrea? Writing Oneself as a Feminist Icon

This article explores the construction of Andrea Dworkin as a public persona, or a ‘feminist icon’, revered by some and demonized by others. It argues that in both her fiction and non-fiction, Dworkin engaged in a process of writing herself as an exceptional woman, a ‘feminist militant’ as she describes herself in the subheading of her 2002 memoir, Heartbreak. The article illustrates Dworkin’s autobiographical logic of exceptionalism by comparing the story told in Heartbreak to the story of Dworkin’s major novel, Mercy, which features a heroine, Andrea, who shares Dworkin’s name and significant biographical details. While Dworkin has insisted that Mercy is not an autobiographical novel, the author undertakes a reading here of Mercy as the story of Dworkin if she had not become the feminist icon of her own and others’ construction. In Mercy, Andrea unsuccessfully attempts to escape the silent, victimized status that Dworkin has insistently argued is imposed upon women. In her repeated victimization, Andrea functions for Dworkin as an ‘everywoman’ who both embodies Dworkin’s world-view and highlights how Dworkin’s own biography exists in tension with some of her central assumptions about women, gender and contemporary society.