The Analogue Computer as a Voltage-Controlled Synthesiser

This paper re-appraises the role of analogue computers within electronic and computer music and provides some pointers to future areas of research. It begins by introducing the idea of analogue computing and placing in the context of sound and music applications. This is followed by a brief examination of the classic constituents of an analogue computer, contrasting these with the typical modular voltage-controlled synthesiser. Two examples are presented, leading to a discussion on some parallels between these two technologies. This is followed by an examination of the current state-of-the-art in analogue computation and its prospects for applications in computer and electronic music

Ultrasonically Assisted Hammer-Action Penetrators in Planetary Regolith

This paper describes the effects of combining ultrasonic vibration with hammer-action style penetrators, such as the HP3 probe on the InSight mission. By synchronizing short pulses of vibration with the impact of the hammer, the number of hammer strikes required to reach a specified depth was reduced by over a third in some cases, depending on the sand and amplitude of vibration used. Additional investigations looked at comparing the performance of pure hammering with pure pulsing, allowing recommendations for operational procedures if this technology were to be taken forward in the future

Polynomial inequalities for non-commuting operators

We prove an inequality for polynomials applied in a symmetric way to non-commuting operators

Preparations for Variable-Gravity Regolith Penetration with an Ultrasonically-Active Probe

The set of experiments proposed in this paper intend to investigate the properties of ultrasonic penetration through granular materials in hypergravity. As part of ESA's 6 th 'Spin Your Thesis' campaign, the University of Glasgow will be allowed to use the Large Diameter Centrifuge at the ESTEC facilities in Noordwijk, Netherlands, to achieve these hypergravity conditions. This paper describes the progress of the design and manufacture of the experimental apparatus, analysis of structural integrity to insure the rig can be subjected to the rigors of hypergravity, and discussion of the anticipated results and implications

Multiplexed on-demand storage of polarization qubits in a crystal

A long-lived and multimode quantum memory is a key component needed for the development of quantum communication. Here we present temporally multiplexed storage of 5 photonic polarization qubits encoded onto weak coherent states in a rare-earth-ion doped crystal. Using spin refocusing techniques we can preserve the qubits for more than half a millisecond. The temporal multiplexing allows us to increase the effective rate of the experiment by a factor of 5, which emphasizes the importance of multimode storage for quantum communication. The fidelity upon retrieval is higher than the maximum classical fidelity achievable with qubits encoded onto single photons and we show that the memory fidelity is mainly limited by the memory signal-to-noise ratio. These results show the viability and versatility of long-lived, multimode quantum memories based on rare-earth-ion doped crystals

Quarterly Economic Commentary, Spring 2013

The Irish economy stabilised in broad terms in 2012, despite a challenging international context and ongoing difficulties in the eurozone in particular. Mainly due to a strong services exports performance, GDP grew by just under 1 per cent in 2012. GNP expanded by 3.4 per cent, although closer inspection reveals that this figure overstates the underlying growth activity (see FitzGerald, this issue). Domestic demand contracted once again, although the pace of contraction was much less severe than in any year since 2008. The unemployment rate averaged 14.7 per cent in 2012 while the fall in employment continued