Sonic Places: In Conversation with Peter Cusack

In this interview, Recomposing the City co-directors Sarah Lappin and Gascia Ouzounian talk with Peter Cusack about his recent work, reflecting in particular on relationships between sound, sound art, planning processes and urban communities. Cusack, a field recordist and sound artist, has been a leading figure in acoustic ecology and soundscape studies for more than two decades

MSGR-based Low Latency Complex Matrix Inversion Architecture

This paper presents a matrix inversion architecture based on the novel Modified Squared Givens Rotations (MSGR) algorithm, which extends the original SGR method to complex valued data, and also corrects erroneous results in the original SGR method when zeros occur on the diagonal of the matrix either initially or during processing. The MSGR algorithm also avoids complex dividers in the matrix inversion, thus minimising the complexity of potential real-time implementations. A systolic array architecture is implemented and FPGA synthesis results indicate a high-throughput low-latency complex matrix inversion solution. © 2008 IEEE.

How crucial is back gate misalignment/oversize in double gate MOSFETs for ultra-low-voltage analog/rf applications?

In the present work, by investigating the influence of source/drain (S/D) extension region engineering (also known as gate-underlap architecture) in planar Double Gate (DG) SOI MOSFETs, we offer new design insights to achieve high tolerance to gate misalignment/oversize in nanoscale devices for ultra-low-voltage (ULV) analog/rf applications. Our results show that (i) misaligned gate-underlap devices perform significantly better than DC devices with abrupt source/drain junctions with identical misalignment, (ii) misaligned gate underlap performance (with S/D optimization) exceeds perfectly aligned DG devices with abrupt S/D regions and (iii) 25% back gate misalignment can be tolerated without any significant degradation in cut-off frequency (f(T)) and intrinsic voltage gain (A(VO)). Gate-underlap DG devices designed with spacer-to-straggle ratio lying within the range 2.5 to 3.0 show best tolerance to misaligned/oversize back gate and indeed are better than self-aligned DG MOSFETs with non-underlap (abrupt) S/D regions. Impact of gate length and silicon film thickness scaling is also discussed. These results are very significant as the tolerable limit of misaligned/oversized back gate is considerably extended and the stringent process control requirements to achieve self-alignment can be relaxed for nanoscale planar ULV DG MOSFETs operating in weak-inversion region. The present work provides new opportunities for realizing future ULV analog/rf design with nanoscale gate-underlap DG MOSFETs. (C) 2008 Elsevier Ltd. All rights reserved.

Impact of gate-source/drain channel architecture on the performance of an operational transconductance amplifier (OTA)

In this work, we report on the significance of gate-source/drain extension region (also known as underlap design) optimization in double gate (DG) FETs to improve the performance of an operational transconductance amplifier (OTA). It is demonstrated that high values of intrinsic voltage gain (A(VO_OTA)) > 55 dB and unity gain frequency (f(T_OTA)) similar to 57 GHz in a folded cascode OTA can be achieved with gate-underlap channel design in 60 nm DG MOSFETs. These values correspond to 15 dB improvement in A(VO_OTA) and three fold enhancement in f(T_OTA) over a conventional non-underlap design. OTA performance based on underlap single gate SOI MOSFETs realized in ultra-thin body (UTB) and ultra-thin body BOX (UTBB) technologies is also evaluated. A(VO_OTA) values exhibited by a DG MOSFET-based OTA are 1.3-1.6 times higher as compared to a conventional UTB/UTBB single gate OTA. f(T_OTA) values for DG OTA are 10 GHz higher for UTB OTAs whereas a twofold improvement is observed with respect to UTBB OTAs. The simultaneous improvement in A(VO_OTA) and f(T_OTA) highlights the usefulness of underlap channel architecture in improving gain-bandwidth trade-off in analog circuit design. Underlap channel OTAs demonstrate high degree of tolerance to misalignment/oversize between front and back gates without compromising the performance, thus relaxing crucial process/technology-dependent parameters to achieve 'idealized' DG MOSFETs. Results show that underlap OTAs designed with a spacer-to-straggle (s/sigma) ratio of 3.2 and operated below a bias current (IBIAS) of 80 mu A demonstrate optimum performance. The present work provides new opportunities for realizing future ultra-wide band OTA design with underlap DG MOSFETs.

Turbo-BLAST: Performance evaluation in correlated Rayleigh-Fading environment

Recent theoretical investigations of spatially correlated multitransmit and multireceive (MTMR) links show that not only independently and identically distributed links, but also spatially correlated links can offer linear capacity growth with increasing number of transmit and receive antennas. In this paper, we explore the suitability of the turbo-BLAST architecture in correlated Rayleigh-fading MTMR environments. In particular, for an MTMR system with a large number of receive antennas, a near optimal performance can be achieved by the turbo-BLAST architecture in spatially and temporarily correlated Rayleigh-fading environments. The performance of turbo-BLAST, in terms of both bit-error rate and spectral efficiency, is analyzed empirically in indoors and correlated outdoor environments.

A versatile content addressable memory architecture

In this paper, a novel configurable content addressable memory (CCAM) cell is proposed, to increase the flexibility of embedded CAMs for SoC employment. It can be easily configured as a Binary CAM (BiCAM) or Ternary CAM (TCAM) without significant penalty of power consumption or searching speed. A 64x128 CCAM array has been built and verified through simulation. ©2007 IEEE.

Reconfigurable full-search video motion estimation architecture

In this paper, a new reconfigurable multi-standard architecture is introduced for integer-pixel motion estimation and a standard-cell based chip design study is presented. This has been designed to cover most of the common block-based video compression standards, including MPEG-2, MPEG-4, H.263, H.264, AVS and WMV-9. The architecture exhibits simpler control, high throughput and relative low hardware cost and highly competitive when compared with excising designs for specific video standards. It can also, through the use of control signals, be dynamically reconfigured at run-time to accommodate different system constraint such as the trade-off in power dissipation and video-quality. The computational rates achieved make the circuit suitable for high end video processing applications. Silicon design studies indicate that circuits based on this approach incur only a relatively small penalty in terms of power dissipation and silicon area when compared with implementations for specific standards.

Defending the Irish Border: The Map of Watchful Architecture

This chapter offers an analysis of a map of the Irish border. The Map of Watchful Architecture charts the history of defensive structures in the border region.

The Making of Modern Turkish Architecture

This is the introductory essay of ARCAM’s (Architectuurcentrum Amsterdam) “Turkey Today: Contemporary Turkish Architecture in Turkey and the Netherlands” Exhibit, which took place in September-November 2004 in Amsterdam, The Netherlands. The author also consulted the curators.

Shifting Ground:Beyond National Architecture

The Irish Pavilion at the Venice Architecture Biennale 2012 charts a position for Irish architecture in a global culture where the modes of production of architecture are radically altered. Ireland is one of the most globalised countries in the world, yet it has developed a national culture of architecture derived from local place as a material construct. We now have to evolve our understanding in the light of the globalised nature of economic processes and architectural production which is largely dependent on internationally networked flows of products, data, and knowledge. We have just begun to represent this situation to ourselves and others. How should a global architecture be grounded culturally and philosophically? How does it position itself outside of shared national reference points?
heneghan peng architects were selected as participants because they are working across three continents on a range of competition-winning projects. Several of these are in sensitive and/or symbolic sites that include three UNESCO World Heritage sites, including the Grand Egyptian Museum in Cairo, the Giants Causeway Visitor Centre in Northern Ireland, and the new Rhine Bridge near Lorelei.
Our dialogue led us to discussing the universal languages of projective geometry and number are been shared by architects and related professionals. In the work of heneghan peng, the specific embodiment of these geometries is carefully calibrated by the choice of materials and the detailed design of their physical performance on site. The stone facade of the Giant’s Causeway Visitor Centre takes precise measure of the properties of the volcanic basalt seams from which it is hewn. The extraction of the stone is the subject of the pavilion wall drawings which record the cutting of stones to create the façade of the causeway centre.
We also identified water as an element which is shared across the different sites. Venice is a perfect place to take measure of this element which suggests links to another site – the Nile Valley which was enriched by the annual flooding of the River Nile. An ancient Egyptian rod for measuring the water level of the Nile inspired the design of the Nilometre - a responsive oscillating bench that invites visitors to balance their respective weights. This action embodies the ways of thinking that are evolving to operate in the globalised world, where the autonomous architectural object is dissolving into an expanded field of conceptual rules and systems. The bench constitutes a shifting ground located in the unstable field of Venice. It is about measurement and calibration of the weight of the body in relation to other bodies; in relation to the site of the installation; and in relation to water. The exhibit is located in the Artiglierie section of the Arsenale. Its level is calibrated against the mark of the acqua alta in the adjacent brickwork of the building which embodies a liminal moment in the fluctuating level of the lagoon.
The weights of bodies, the level of water, changes over time, are constant aspects of design across cultures and collectively they constitute a common ground for architecture - a ground shared with other design professionals. The movement of the bench required complex engineering design and active collaboration between the architects, engineers and fabricators. It is a kind of prototype – a physical object produced from digital data that explores the mathematics at play – the see-saw motion invites the observer to become a participant, to give it a test drive. It shows how a simple principle can generate complex effects that are difficult to predict and invites visitors to experiment and play with them.

The Map of Watchful Architecture

The international border between Northern Ireland and the South (the Republic of Ireland) came into being in 1922, but there are many important historical antecedents to the notion and expression of spatial separation in this borderland. The author identifies historical precedents and links them to recent defensive features in order to generate a 'map of watchful architecture' that includes recent and much older elements.