4,046 research outputs found
A New Method for Multi-Bit and Qudit Transfer Based on Commensurate Waveguide Arrays
The faithful state transfer is an important requirement in the construction
of classical and quantum computers. While the high-speed transfer is realized
by optical-fibre interconnects, its implementation in integrated optical
circuits is affected by cross-talk. The cross-talk between densely packed
optical waveguides limits the transfer fidelity and distorts the signal in each
channel, thus severely impeding the parallel transfer of states such as
classical registers, multiple qubits and qudits. Here, we leverage on the
suitably engineered cross-talk between waveguides to achieve the parallel
transfer on optical chip. Waveguide coupling coefficients are designed to yield
commensurate eigenvalues of the array and hence, periodic revivals of the input
state. While, in general, polynomially complex, the inverse eigenvalue problem
permits analytic solutions for small number of waveguides. We present exact
solutions for arrays of up to nine waveguides and use them to design realistic
buses for multi-(qu)bit and qudit transfer. Advantages and limitations of the
proposed solution are discussed in the context of available fabrication
techniques
Deformation effects on a dispersion hardened alloys
Creep and creep rupture deformation and tensile tests of nickel alloy
CoachNet: The further development of a coordinated network for sport coaching in Europe
Leeds Metropolitan University (LMU), in partnership with the European Coaching Council (ECC), was successful in a bid to the European Commission under the Preparatory Action in the Field of Sport (EAC/18/2011). The project was designed to develop an innovative approach that would contribute to the strengthening of the organisation of sport in Europe as part of the āgood governance, strand of the EU Preparatory Action in the Field of Sport. The primary objective was to examine ways in which the organisation of coaching could be enhanced in Europe, with a particular focus on the greater involvement of coaches in decisionmaking. In exploring ways to maximise the āvoice of the coachā, the partnership between LMU and ECC was central to the project. ECC is the continental division of the International Council for Coaching Excellence (ICCE). Through its network, ECC was in a position to identify current organisational arrangements for coaching across Europe. LMU is a well established research and practice oriented university in the UK and played a lead role in coordinating the project and guiding the research methodology through its Sport Coaching and Physical Education (SCOPE) Research and Enterprise Centre. Varying arrangements for the development and management of coaching were observed through a study of European countries. Within this varied landscape, the representation of coaches was sporadic, ranging from no representative mechanism to a number of good practice examples that made provision for the tiered engagement of coaches depending on their role; sport and coaching status category. These examples included confederated models across sports; blended models across coaching status categories and single and multi-sport models for the engagement and representation of coaches. The study concluded that there is a need for a more considered approach to the involvement of coaches in decision-making, with a number of recommendations developed for consideration by member states and the European divisions of the International Federations. These recommendations proposed that the structure of ECC as the European arm of ICCE be reviewed, with the intention to more strongly engage organisations that have been established to represent the voice of coaches and leading to a re-structuring of the organisation. In this context, ICCE and ECC should play an even stronger advocacy, representative and action role in establishing coaching as a blended profession, which includes volunteer, part-time paid and full-time paid coaches. More coherent structures for the engagement of coaches in each sport and country are also recommended. This should occur as part of a wider commitment that the principle of listening to and hearing the voice of the coach should become more strongly embedded within the way in which sporting and related organisations operate. The EU is well placed to lead on this type of approach, ensuring the coaches are more fully engaged in social dialogue and in the process to further enhance the role of sport and coaching in Europe. Further research is also recommended on the nature, needs and demographics of the coaching workforce. All of these approaches need to be tempered with the realisation that coaches are individual decision-makers, operating in a wide variety of contexts and many of whom do not show a propensity for involvement in formal ārepresentativeā structures. The need for alternative methods to connect with and engage coaches was, therefore, identified. These include a more segmented approach to engaging with coaches, depending on their coaching role and status, as well as the utilisation of more informal modes of web-based communication to connect directly with coaches in their daily lives. In all existing and future scenarios, the key role of federations at the national and international level in seeking, activating and allocating financial and other resources to connect with and support their coaches was highlighted. The findings have been notified to ICCE for formal consideration, leading to changes in the ways in which the voice of the coach is more clearly represented within the work of the organisation. ICCE should continue to work closely with the EU Sport Unit to ensure that the recommendations of this report are implemented and evaluated on an on-going basis
Fast T2 Mapping with Improved Accuracy Using Undersampled Spin-echo MRI and Model-based Reconstructions with a Generating Function
A model-based reconstruction technique for accelerated T2 mapping with
improved accuracy is proposed using undersampled Cartesian spin-echo MRI data.
The technique employs an advanced signal model for T2 relaxation that accounts
for contributions from indirect echoes in a train of multiple spin echoes. An
iterative solution of the nonlinear inverse reconstruction problem directly
estimates spin-density and T2 maps from undersampled raw data. The algorithm is
validated for simulated data as well as phantom and human brain MRI at 3 T. The
performance of the advanced model is compared to conventional pixel-based
fitting of echo-time images from fully sampled data. The proposed method yields
more accurate T2 values than the mono-exponential model and allows for
undersampling factors of at least 6. Although limitations are observed for very
long T2 relaxation times, respective reconstruction problems may be overcome by
a gradient dampening approach. The analytical gradient of the utilized cost
function is included as Appendix.Comment: 10 pages, 7 figure
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