Decoherence of a single-ion qubit immersed in a spin-polarized atomic bath

We report on the immersion of a spin-qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the possibility of a precise microscopic description, which allows us to understand dynamics and decoherence from first principles. We observe the spin dynamics of the qubit and measure the decoherence times (T1 and T2), which are determined by the spin-exchange interaction as well as by an unexpectedly strong spin-nonconserving coupling mechanism

Myocardium wall thickness transducer and measuring method

A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described

Semantic modelling of user interests based on cross-folksonomy analysis

The continued increase in Web usage, in particular participation in folksonomies, reveals a trend towards a more dynamic and interactive Web where individuals can organise and share resources. Tagging has emerged as the de-facto standard for the organisation of such resources, providing a versatile and reactive knowledge management mechanism that users find easy to use and understand. It is common nowadays for users to have multiple profiles in various folksonomies, thus distributing their tagging activities. In this paper, we present a method for the automatic consolidation of user profiles across two popular social networking sites, and subsequent semantic modelling of their interests utilising Wikipedia as a multi-domain model. We evaluate how much can be learned from such sites, and in which domains the knowledge acquired is focussed. Results show that far richer interest profiles can be generated for users when multiple tag-clouds are combine

Navigating the city: dialectics of everyday urbanism

How might we conceptualise and research everyday urbanism? By examining the making of everyday life in a low-income neighbourhood in Uganda, we argue that a dialectics of everyday urbanism is a useful approach for understanding urban poverty. This dialectical approach examines how marginalised urban dwellers navigate the city in the relative absence of formal infrastructure systems, service provision and state welfare, and in turn exceed those limitations through forging connections, capacities and opportunities. We reveal the ‘social infrastructures’ that people put together to sustain life, as well as the limits of and placed on these infrastructures, from the legacies of structural adjustment to ongoing forms of demolition and disinvestment. We identify a set of practices that operate alongside social infrastructure – ‘coordination’, ‘consolidation’ and ‘speculation’ – important in the composition of everyday urban life. In doing so, we reflect on how we might research the dialectics of everyday urbanism, and here a ‘follow-along participant observation’ (FAPO) methodology has significant potential. Our arguments emerge from research with residents in Kampala, but open out questions for how we conceive and research everyday life and urban infrastructure more generally

Flattening the World of Legal Services? The Ethical and Liability Minefields of Offshoring Legal and Law-Related Services

This article examines offshore outsourcing of legal and law-related services as the newest twist in the international market for legal services. We consider the impact of offshore outsourcing on the profession generally and analyze the ethical issues raised by offshore outsourcing, both as it exists today and as the practice may develop in the future. The article begins by situating offshore outsourcing in the framework of relationships created in the context of delivery of legal services. This framework is used, in turn, to construct a structure of analysis for the ethical implications of offshore outsourcing. Lawyers who outsource to offshore providers must conduct an investigation to ensure that the referral is appropriate. We also consider the potential reputation and economic benefits and disadvantages to law firms and legal departments in outsourcing offshore. We find that offshore outsourcing creates new opportunities for non-U.S. lawyers without putting them on equal footing with lawyers trained and licensed in the U.S. Instead, as with many aspects of globalization, offshore outsourcing emphasizes the divisions already present in the legal profession

Flattening the World of Legal Services? The Ethical and Liability Minefields of Offshoring Legal and Law-Related Services

This article examines offshore outsourcing of legal and law-related services as the newest twist in the international market for legal services. We consider the impact of offshore outsourcing on the profession generally and analyze the ethical issues raised by offshore outsourcing, both as it exists today and as the practice may develop in the future. The article begins by situating offshore outsourcing in the framework of relationships created in the context of delivery of legal services. This framework is used, in turn, to construct a structure of analysis for the ethical implications of offshore outsourcing. Lawyers who outsource to offshore providers must conduct an investigation to ensure that the referral is appropriate. We also consider the potential reputation and economic benefits and disadvantages to law firms and legal departments in outsourcing offshore. We find that offshore outsourcing creates new opportunities for non-U.S. lawyers without putting them on equal footing with lawyers trained and licensed in the U.S. Instead, as with many aspects of globalization, offshore outsourcing emphasizes the divisions already present in the legal profession

Sample-Efficient Model-Free Reinforcement Learning with Off-Policy Critics

Value-based reinforcement-learning algorithms provide state-of-the-art results in model-free discrete-action settings, and tend to outperform actor-critic algorithms. We argue that actor-critic algorithms are limited by their need for an on-policy critic. We propose Bootstrapped Dual Policy Iteration (BDPI), a novel model-free reinforcement-learning algorithm for continuous states and discrete actions, with an actor and several off-policy critics. Off-policy critics are compatible with experience replay, ensuring high sample-efficiency, without the need for off-policy corrections. The actor, by slowly imitating the average greedy policy of the critics, leads to high-quality and state-specific exploration, which we compare to Thompson sampling. Because the actor and critics are fully decoupled, BDPI is remarkably stable, and unusually robust to its hyper-parameters. BDPI is significantly more sample-efficient than Bootstrapped DQN, PPO, and ACKTR, on discrete, continuous and pixel-based tasks. Source code: https://github.com/vub-ai-lab/bdpi.Comment: Accepted at the European Conference on Machine Learning 2019 (ECML

Flattening the World of Legal Services? The Ethical and Liability Minefields of Offshoring Legal and Law-Related Services

This article examines offshore outsourcing of legal and law-related services as the newest twist in the international market for legal services. We consider the impact of offshore outsourcing on the profession generally and analyze the ethical issues raised by offshore outsourcing, both as it exists today and as the practice may develop in the future. The article begins by situating offshore outsourcing in the framework of relationships created in the context of delivery of legal services. This framework is used, in turn, to construct a structure of analysis for the ethical implications of offshore outsourcing. Lawyers who outsource to offshore providers must conduct an investigation to ensure that the referral is appropriate. We also consider the potential reputation and economic benefits and disadvantages to law firms and legal departments in outsourcing offshore. We find that offshore outsourcing creates new opportunities for non-U.S. lawyers without putting them on equal footing with lawyers trained and licensed in the U.S. Instead, as with many aspects of globalization, offshore outsourcing emphasizes the divisions already present in the legal profession