Assembling Micron/Nanoscale Electronic Components using Optoelectronic Tweezers

The aim of this work is to develop a new method with the potential to revolutionise the process of assembling electronic components into circuits. We aim to produce a step change in the size of the smallest components that can be handled from the current smallest standard component size of 400×200 microns (0402 metric) down to components a few microns across and even nanostructured components (based upon graphene, nanowires or nanotubes, for example). This will be accomplished by developing a radically new assembly strategy based on a touch-less manipulation technique known as optoelectronic tweezers (OET). We have demonstrated the use of OET to manipulate conductive silver nanowires into different patterns. A proof-ofconcept demonstration was also made to quantify the feasibility of using OET to manipulate silver nanowires to form a conductive metal path between two electrodes

Hoodsquare: Modeling and Recommending Neighborhoods in Location-based Social Networks

Information garnered from activity on location-based social networks can be harnessed to characterize urban spaces and organize them into neighborhoods. In this work, we adopt a data-driven approach to the identification and modeling of urban neighborhoods using location-based social networks. We represent geographic points in the city using spatio-temporal information about Foursquare user check-ins and semantic information about places, with the goal of developing features to input into a novel neighborhood detection algorithm. The algorithm first employs a similarity metric that assesses the homogeneity of a geographic area, and then with a simple mechanism of geographic navigation, it detects the boundaries of a city's neighborhoods. The models and algorithms devised are subsequently integrated into a publicly available, map-based tool named Hoodsquare that allows users to explore activities and neighborhoods in cities around the world. Finally, we evaluate Hoodsquare in the context of a recommendation application where user profiles are matched to urban neighborhoods. By comparing with a number of baselines, we demonstrate how Hoodsquare can be used to accurately predict the home neighborhood of Twitter users. We also show that we are able to suggest neighborhoods geographically constrained in size, a desirable property in mobile recommendation scenarios for which geographical precision is key.Comment: ASE/IEEE SocialCom 201

Hazing Iran: Satellite Imagery, Human Rights, and City as Camp

As perhaps most obviously evidenced in the political maneuverings that led up to the second Gulf War in 2003, the use of satellite imagery to document spatial terrain is often, and almost instantly, politicized. In the two images presented here, this politicization takes on a two-way relationship and is open to contrasting and inevitably dualistic readings. One way of describing their relationship is as "Target" and "Aftermath". On the left, we have an image of the nuclear plant near the Iranian city of Qom, annotated in this version by the US security services to highlight 'suspicious' activity said to evidence the nuclear ambitions of the Iranian government. On the right, we are presented with an image of Tehran under heavy smog in 2013 released by the Iranian government itself. Although the official Iranian explanation for this smog is the general population density and industrialization of the city, it has now been acknowledged, or is at least extensively argued, that the pollution it documents is a direct result of the economic sanctions imposed by the United States in 2010 that banned the sale of refined fuel to the country. Facing a major energy crisis that would completely stall the economy, the Iranian government opted to produce a "bathtub mix" of far inferior quality oil that has been releasing deadly exhaust into the already dense air of Iran for the past three years. The "Target", as the first image shows, is Iran's nuclear program, which lies at the crux of complicated historical animosities currently evident between the US and Iranian governments. Taken at very high resolution (2.5 meters per pixel) from outer space, the image presents itself as tunnel-vision precision — each point is a piece of data and each piece of data details coordinates, date, and time. It is on the back of such supposed satellite precision that the crippling economic sanctions of the US's policy of containment are justified. However, the aftermath of these sanctions has not been the cessation of Iran's nuclear program, but rather the suffocation of Tehran. Indeed, it has been argued that the inhabitants of Tehran are almost literally "choking to death". By the standards of the sanctions' purported aims, the result seems more an egregious misfire than a successful piece of foreign policy. The reality behind these images and their conflicting ascribed narratives is far from clear. The effects on the people of Iran are also not only equally unclear, they are deliberately hazed. Employing Giorgio Agamben's notions of the abstraction of the citizen to 'bare life' and its corollary of the 'Camp' as the 'Nomos' of the Modern, this paper attempts to decipher these images, their politicized readings, and the way in which the sites of human life in and near their locations – the occupants of the city of Qom in the first instance and those of Tehran in the second – have been conspicuously erased. It will argue that this visual erasure from spatial representation has fundamental implications for the human rights of the inhabitants of these cities and, by extension, Iran and a politicized world more generally. In doing so, it will suggest that as spaces and places of political conflict are ever more frequently presented through the medium of the satellite image, a deeply politicized reading of their structures, narratives and spatial representative techniques becomes ever more important