Polarisation independent resistively loaded frequency selective surface absorber with optimum oblique incidence performance

This study presents the design of a thin electromagnetic absorber which exhibits radar backscatter suppression that is independent of the wave polarisation at large incidence angles. The structure consists of a metal backed printed frequency selective surface (FSS), with resistors placed across narrow gaps inserted in the middle of each of the four sides of the conductor loops. The geometry of the periodic array and the value of the vertical and horizontal resistor pairs are carefully chosen to present a real impedance of 377 Ω at the centre operating frequency for both TE and TM polarised waves. Angular sensitivity and reflectivity bandwidth have been investigated for FSS absorber designs with thicknesses of 1, 2 and 3 mm. Each of the three structures was optimised to work at a centre frequency of 10 GHz and an incident angle of 45°. The design methodology is verified by measuring the radar backscatter suppression from a 3 mm (l / 10) thick screen in the frequency range 8–12 GHz. The absorber construction was simplified by filling the four metal gaps in each unit cell with shielding paint, and selecting the ink thickness to give the two required surface resistance values.

Polarization Distortion as a Means for Securing Wireless Communication

This paper presents a simple polarization encoding strategy that operates using only single element dual port transmit and receive antennas in such a way that selective spatial scrambling of QPSK data can be effected. The key transmitter and receiver relationships needed for this operation to occur are derived. The system is validated using a cross dipole antenna arrangement. Unlike all previously reported physical layer wireless solutions the approach developed in this paper transfers the security property to the receive side resulting in very simple transmit and receive side architectures thus avoiding the need for near field modulated array technology. In addition the scheme permits, for the first time, multiple spatially separated secured receive sites to operate in parallel.

Chan ceist duit a bhás go bráth: 'An Lon Dubh Báite'

This article discusses an enigmatic poem by the 18th century Gaelic poet Séamas Mac Cuarta, and three subsequent translations into English. The poem is written in the 'Trí Rann agus Amhrán' form, reminiscent of the English sonnet.

From Boys to Men Overview and Recommendations

The From Boys to Men Project was funded by the Economic and Social Research
Council to explore why some boys become domestic abuse perpetrators when
others do not. In so doing, it sought to establish what more could be done to
reduce the number of young men who become perpetrators. The study
involved three phases of data collection including: Phase 1 - a survey of 1203
school children aged 13-14; Phase 2 - focus groups with 69 young people aged
13-19; and Phase 3 - life history interviews with 30 young men, aged 16-21,
who had experienced domestic abuse as victims, perpetrators or witnesses.
Reports on all stages of the project are freely available on our website
www.boystomenproject.com.
This report provides a brief overview of what we found and what
recommendations follow from the project’s findings.

Robust bimodal person identification using face and speech with limited training data and corruption of both modalities

This paper presents a novel method of audio-visual fusion for person identification where both the speech and facial modalities may be corrupted, and there is a lack of prior knowledge about the corruption. Furthermore, we assume there is a limited amount of training data for each modality (e.g., a short training speech segment and a single training facial image for each person). A new representation and a modified cosine similarity are introduced for combining and comparing bimodal features with limited training data as well as vastly differing data rates and feature sizes. Optimal feature selection and multicondition training are used to reduce the mismatch between training and testing, thereby making the system robust to unknown bimodal corruption. Experiments have been carried out on a bimodal data set created from the SPIDRE and AR databases with variable noise corruption of speech and occlusion in the face images. The new method has demonstrated improved recognition accuracy.

Crossing the Threshold: Mysticism, Liminality, and Remedios Varo’s Bordando el manto terrestre (1961–2)

In this article we propose to take up the question of the painter’s work in connection with liminality more explicitly. We will argue that the limen Varo’s heroines cross is a psychological one that takes them through a process culminating in a rebirth of the self, and that to the extent they are in-between identities and involved in a process of initiation, they can be considered liminars (Turner). We will also argue that in order to develop this theme, which culminates in her most autobiographical work, the triptych Bordando el manto terrestre (1961–2), the artist needed to find a way conceptually to bridge surrealism and her interest in mysticism. She would have found a sympathetic approach in Jung, one of the founders of psychoanalysis, who turned explicitly to the question of religion in the troubled thirties, though, as we shall see, she revised his androcentric approach. We will suggest that Jung’s writing helped the artist make a transition from surrealism to esoteric spirituality.