Aircraft rotor blade with passive tuned tab

A structure for reducing vibratory airloading in a rotor blade with a leading edge and a trailing edge includes a cut out portion at the trailing edge. A substantially wedge shaped cross section, inertially deflectable tab, also with a leading edge and a trailing edge is pivotally mounted in the cut out portion. The trailing edge of the tab may move above and below the rotor blade. A torsion strap applies force against the tab when the trailing edge of the tab is above and below the rotor blade. A restraining member is slidably movable along the torsion strap to vary torsional biasing force supplied by the torsion bar to the tab. A plurality of movable weights positioned between plates vary a center of gravity of the tab. Skin of the tab is formed from unidirectional graphite and fiberglass layers. Sliders coupled with a pinned degree of freedom at rod eliminate bending of tab under edgewise blade deflection

Enhanced fault-tolerant quantum computing in dd-level systems

Error correcting codes protect quantum information and form the basis of fault tolerant quantum computing. Leading proposals for fault-tolerant quantum computation require codes with an exceedingly rare property, a transverse non-Clifford gate. Codes with the desired property are presented for $d$-level, qudit, systems with prime $d$. The codes use $n=d-1$ qudits and can detect upto $\sim d/3$ errors. We quantify the performance of these codes for one approach to quantum computation, known as magic state distillation. Unlike prior work, we find performance is always enhanced by increasing $d$.Comment: Author's final copy. Changes includes correction to plot in figure

'Really on the ball': exploring the implications of teachers' PE-CPD experience

Continuing professional development (CPD) is currently high on the Scottish Education agenda. Recent curriculum reform in Scotland, with the introduction of Curriculum for Excellence, places physical education (PE) at the forefront for its role in directly supporting learners' mental, emotional, social and physical well-being. This emphasis on PE, along with concerns about the health of the nation, has resulted in a nationwide initiative providing non-specialist teachers of primary PE with the opportunity to develop a specialism in the subject through government-funded CPD programmes at postgraduate level. Using Knowles' andragogical model as a framework, this paper reports data from a larger research study that evaluated a Scottish PE-CPD initiative. This paper comprises a single case holistic study investigating the impact and implications of a PE-CPD programme through the professional learning journeys, from the outset until completion, of four teachers: a nursery teacher, a class teacher, a cluster cover teacher and a PE specialist who participated in the programme. Data were collected over one academic year using two-stage questionnaire interviews and were analysed thematically with special attention given to the emerging general themes to achieve a holistic understanding of the case. Study findings endorse the positive impact of using the andragogical model of adult learning combined with the literature-supported characteristics of effective PE-CPD programmes. Teachers' perspectives on their CPD experiences, integration of acquired learning into working contexts and teaching post-PE-CPD were then examined to determine the next steps. This led to critical reflection on the implications of the findings for the teachers' ongoing professional development. We then challenged the role that university providers play in supporting teachers' lifelong learning. Instead, we suggest new school-university partnerships and alternative ways to support capacity building and lifelong learning towards a sustainable transformational change in Scotland's primary PE

Specifying attracting cycles for Newton maps of polynomials

We show that for any set of n distinct points in the complex plane, there exists a polynomial p of degree at most n+1 so that the corresponding Newton map, or even the relaxed Newton map, for p has the given points as a super-attracting cycle. This improves the result due to Plaza and Romero (2011), which shows how to find such a polynomial of degree 2n. Moreover we show that in general one cannot improve upon degree n+1. Our methods allow us to give a simple, constructive proof of the known result that for each cycle length n at least 2 and degree d at least 3, there exists a polynomial of degree d whose Newton map has a super-attracting cycle of length n.Comment: 18 pages, 2 figure

Distributed quantum information processing with minimal local resources

We present a protocol for growing graph states, the resource for one-way quantum computing, when the available entanglement mechanism is highly imperfect. The distillation protocol is frugal in its use of ancilla qubits, requiring only a single ancilla qubit when the noise is dominated by one Pauli error, and two for a general noise model. The protocol works with such scarce local resources by never post-selecting on the measurement outcomes of purification rounds. We find that such a strategy causes fidelity to follow a biased random walk, and that a target fidelity is likely to be reached more rapidly than for a comparable post-selecting protocol. An analysis is presented of how imperfect local operations limit the attainable fidelity. For example, a single Pauli error rate of 20% can be distilled down to $\sim 10$ times the imperfection in local operations.Comment: 4 pages of main paper with an additional 1 page appendix, 5 figures. Please contact me with any comment

Gaussification and entanglement distillation of continuous variable systems: a unifying picture

Distillation of entanglement using only Gaussian operations is an important primitive in quantum communication, quantum repeater architectures, and distributed quantum computing. Existing distillation protocols for continuous degrees of freedom are only known to converge to a Gaussian state when measurements yield precisely the vacuum outcome. In sharp contrast, non-Gaussian states can be deterministically converted into Gaussian states while preserving their second moments, albeit by usually reducing their degree of entanglement. In this work - based on a novel instance of a non-commutative central limit theorem - we introduce a picture general enough to encompass the known protocols leading to Gaussian states, and new classes of protocols including multipartite distillation. This gives the experimental option of balancing the merits of success probability against entanglement produced.Comment: 4 + 4 pages, final versio

Optimum satellite orbits for accurate measurement of the earth's radiation budget, summary

The optimum set of orbit inclinations for the measurement of the earth radiation budget from spacially integrating sensor systems was estimated for two and three satellite systems. The best set of the two were satellites at orbit inclinations of 80 deg and 50 deg; of three the inclinations were 80 deg, 60 deg and 50 deg. These were chosen on the basis of a simulation of flat plate and spherical detectors flying over a daily varying earth radiation field as measured by the Nimbus 3 medium resolution scanners. A diurnal oscillation was also included in the emitted flux and albedo to give a source field as realistic as possible. Twenty three satellites with different inclinations and equator crossings were simulated, allowing the results of thousand of multisatellite sets to be intercompared. All were circular orbits of radius 7178 kilometers

Bound States for Magic State Distillation in Fault-Tolerant Quantum Computation

Magic state distillation is an important primitive in fault-tolerant quantum computation. The magic states are pure non-stabilizer states which can be distilled from certain mixed non-stabilizer states via Clifford group operations alone. Because of the Gottesman-Knill theorem, mixtures of Pauli eigenstates are not expected to be magic state distillable, but it has been an open question whether all mixed states outside this set may be distilled. In this Letter we show that, when resources are finitely limited, non-distillable states exist outside the stabilizer octahedron. In analogy with the bound entangled states, which arise in entanglement theory, we call such states bound states for magic state distillation.Comment: Published version. This paper builds on a theorem proven in "On the Structure of Protocols for Magic State Distillation", arXiv:0908.0838. These two papers jointly form the content of a talk entitled "Neither Magical nor Classical?", which was presented at TQC 2009, Waterlo