Ignorance is bliss: General and robust cancellation of decoherence via no-knowledge quantum feedback

A "no-knowledge" measurement of an open quantum system yields no information about any system observable; it only returns noise input from the environment. Surprisingly, performing such a no-knowledge measurement can be advantageous. We prove that a system undergoing no-knowledge monitoring has reversible noise, which can be cancelled by directly feeding back the measurement signal. We show how no-knowledge feedback control can be used to cancel decoherence in an arbitrary quantum system coupled to a Markovian reservoir that is being monitored. Since no-knowledge feedback does not depend on the system state or Hamiltonian, such decoherence cancellation is guaranteed to be general, robust and can operate in conjunction with any other quantum control protocol. As an application, we show that no-knowledge feedback could be used to improve the performance of dissipative quantum computers subjected to local loss.Comment: 6 pages + 2 pages supplemental material, 3 figure

Teledesic Global Wireless Broadband Network: Space Infrastructure Architecture, Design Features and Technologies

The Teledesic satellites are a new class of small satellites which demonstrate the important commercial benefits of using technologies developed for other purposes by U.S. National Laboratories. The Teledesic satellite architecture, subsystem design features, and new technologies are described. The new Teledesic satellite manufacturing, integration, and test approaches which use modern high volume production techniques and result in surprisingly low space segment costs are discussed. The constellation control and management features and attendant software architecture features are addressed. After briefly discussing the economic and technological impact on the USA commercial space industries of the space communications revolution and such large constellation projects, the paper concludes with observations on the trend toward future system architectures using networked groups of much smaller satellites

Tectonic: a networked, generative and interactive, conducting environment for iPad

This paper describes the concept, implementation and context of Tectonic: Rodinia for four realtime composer-conductoors and ensemble. In this work, an addition to the reqertoire of the Decibel Scoreplayer, iPads art networked together using the bonjour protocol to manage connectivity over the network. Unlike previous Scoreplayer works, Rodinia combines conductor view control interfaces, performer view notation interfaces and an audience view overview interface, separately identified by manual connection and yet mutually interactive. Notation is communicated to an ensemble via scores independently generated in realtime in each performer view and amalgamated schematically in the :audience view interface. Interaction in the work is enacted through a collision avoidant algorithm that modifies the choices of each conductor by deflecting the streams of notation according to evaluation of the Mass and proximity to other streams, reflecting the concept of shifting Tectonic plates that crush and reform each other\u27s placement

Improved hydrogen gas production in microbial electrolysis cells using inexpensive recycled carbon fibre fabrics

Growing energy demands of wastewater treatment have made it vital for water companies to develop less energy intensive processes for treating wastewater if net zero emissions are to be achieved by 2050. Microbial electrolysis cells (MECs) have the potential to do this by treating water and producing renewable hydrogen gas as a product, but capital and operational costs have slowed their deployment. By using recycled carbon fibre mats, commercially viable MECs can brought closer to reality, where recycled carbon fibre anode MECs treating real wastewater (normalised ~3100 L d−1) were producing 66.77 L H2 d−1 while graphite felt anode MECs produced 3.65 L H2 d−1 per 1 m3 reactor, anodes costing £5.53 m−2 and £88.36 m−2 respectively, resulting in a total anode cost saving of 93%. This could incentivise the development of larger pilot systems, opening the door for generating greater value and a more sustainable wastewater treatment industry

The effect of alternate schooling on the self-concept

In teaching, traditionally the nature of the learner has had little to do wi th what we decided to teach him (Weinstein, 1974). Existential psychology has taken a more individual view of behavior. the existential researcher cannot see the person from outside that person\u27s world. He makes an effort to see the person\u27s world as that person sees it. Existential psychology has attacked the idea of interpreting individual behavior in terms of abstract general laws Each person is dealt with as a unique person. (May,, 1958