716 research outputs found
Who guards the guardians of monetary stability and financial stability? That is the key question behind the debate about the accountability of the Bank of England
Rosa Lastra unpicks the debate surrounding the accountability of the increasingly powerful Bank of England. She argues that the Bank of England should be made accountable to Parliament, and calls for a better understanding of how we should assess the Bank’s role in creating financial stability
Entanglement properties in the Inhomogeneous Tavis-Cummings model
In this work we study the properties of the atomic entanglement in the
eigenstates spectrum of the inhomogeneous Tavis-Cummings Model. The
inhomogeneity is present in the coupling among the atoms with quantum
electromagnetic field. We calculate analytical expressions for the concurrence
and we found that this exhibits a strong dependence on the inhomogeneity.Comment: 5 pages, 5 figure
Phonon-induced entanglement dynamics of two donor-based charge quantum bits
The entanglement dynamics of a pair of donor-based charge qubits is obtained
in analytical form. The disentanglement is induced by off resonant scattering
of acoustical phonons in the semiconductor host. According to our results a
rather unusual recovery of entanglement occurs that depends on the geometrical
configuration of the qubits. In addition, for large times a non-vanishing
stationary entanglement is predicted. For the cases of one and two initial
excitations a simple kinetic interpretation allows for an adequate analysis of
the observed dynamics. Our results also reveal a direct relation between the
disentanglement rate and the inter-donor decoherence rates
Towards an analytical description of active microswimmers in clean and in surfactant-covered drops
Geometric confinements are frequently encountered in the biological world and
strongly affect the stability, topology, and transport properties of active
suspensions in viscous flow. Based on a far-field analytical model, the
low-Reynolds-number locomotion of a self-propelled microswimmer moving inside a
clean viscous drop or a drop covered with a homogeneously distributed
surfactant, is theoretically examined. The interfacial viscous stresses induced
by the surfactant are described by the well-established Boussinesq-Scriven
constitutive rheological model. Moreover, the active agent is represented by a
force dipole and the resulting fluid-mediated hydrodynamic couplings between
the swimmer and the confining drop are investigated. We find that the presence
of the surfactant significantly alters the dynamics of the encapsulated swimmer
by enhancing its reorientation. Exact solutions for the velocity images for the
Stokeslet and dipolar flow singularities inside the drop are introduced and
expressed in terms of infinite series of harmonic components. Our results offer
useful insights into guiding principles for the control of confined active
matter systems and support the objective of utilizing synthetic microswimmers
to drive drops for targeted drug delivery applications.Comment: 19 pages, 7 figures. Regular article contributed to the Topical Issue
of the European Physical Journal E entitled "Physics of Motile Active Matter"
edited by Gerhard Gompper, Clemens Bechinger, Holger Stark, and Roland G.
Winkle
A first step to accelerating fingerprint matching based on deformable minutiae clustering
Fingerprint recognition is one of the most used biometric
methods for authentication. The identification of a query fingerprint requires
matching its minutiae against every minutiae of all the fingerprints
of the database. The state-of-the-art matching algorithms are costly, from
a computational point of view, and inefficient on large datasets. In this
work, we include faster methods to accelerating DMC (the most accurate
fingerprint matching algorithm based only on minutiae). In particular,
we translate into C++ the functions of the algorithm which represent the
most costly tasks of the code; we create a library with the new code and
we link the library to the original C# code using a CLR Class Library
project by means of a C++/CLI Wrapper. Our solution re-implements
critical functions, e.g., the bit population count including a fast C++
PopCount library and the use of the squared Euclidean distance for calculating
the minutiae neighborhood. The experimental results show a
significant reduction of the execution time in the optimized functions of
the matching algorithm. Finally, a novel approach to improve the matching
algorithm, considering cache memory blocking and parallel data processing,
is presented as future work.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Quantum recoil effects in finite-time disentanglement of two distinguishable atoms
Starting from the requirement of distinguishability of two atoms by their
positions, it is shown that photon recoil has a strong influence on finite-time
disentanglement and in some cases prevents its appearance. At near-field inter
atomic distances well localized atoms, with maximally one atom being initially
excited, may suffer disentanglement at a single finite time or even at a series
of equidistant finite times, depending on their mean inter atomic distance and
their initial electronic preparation.Comment: 13 pages, 1 figure, submitted to Physical Review on august 2
Web based system architecture for long pulse remote experimentation
Remote experimentation (RE) methods will be essential in next generation fusion devices. Requirements for long pulse RE will be: on-line data visualization, on-line data acquisition processes monitoring and on-line data acquisition systems interactions (start, stop or set-up modifications). Note that these methods are not oriented to real-time control of fusion plant devices.
INDRA Sistemas S.A., CIEMAT (Centro de Investigaciones Energéticas Medioambientales y Tecnológicas) and UPM (Universidad Politécnica de Madrid) have designed a specific software architecture for these purposes. The architecture can be supported on the BeansNet platform, whose integration with an application server provides an adequate solution to the requirements. BeansNet is a JINI based framework developed by INDRA, which makes easy the implementation of a remote experimentation model based on a Service Oriented Architecture. The new software architecture has been designed on the basis of the experience acquired in the development of an upgrade of the TJ-II remote experimentation system
Efectos del tráfico del tractor sobre la distribución de la compactación del suelo y los rendimientos de trigo en España
395-403The general objective of this paper was to quantify the changes in the physical properties of an Aridisol soil and the effect on wheat yield due to agricultural tractors traffic in the Vélez Blanco District, Almería Spain. Parameters measured were cone index (CI) in the 0-600 mm depth profile, bulk density (BD) and rut depth; the variable wheat yields (WY) was measured too. The traffic treatments applied were: 0 (control plot), 1, 3, 5, and 7 tractor passes in the same tracks. Each experimental plot was trafficked with two tractors, one light (60 kN) and one heavy (80 kN). In topsoil (0-200 mm), up to five passes of the heavy (HT) and light tractors (LT), as in one and three passes, the BD and CI values responded to the ground pressure being higher in absolute value for LT. For the 200 to 400 mm depth range HT caused higher CI (1,570 to 2,200 kPa) and BD (1.38 to 1.68 Mg m-3) values than LT. Eight months later, WY was evaluated in tractor's track areas and decreases in the range of 18-38 percent, were measured. For seven passes the applications of total loads of 80 and 60 kN increased BD up to 1.5 Mg m-3 at depths of 200-600 mm. Although soil had high bulk density prior to traffic treatments, a significant increment of subsoil compaction still occurred due to the high traffic intensities applied
Calculation of quantum discord for qubit-qudit or N qubits
Quantum discord, a kind of quantum correlation, is defined as the difference
between quantum mutual information and classical correlation in a bipartite
system. It has been discussed so far for small systems with only a few
independent parameters. We extend here to a much broader class of states when
the second party is of arbitrary dimension d, so long as the first, measured,
party is a qubit. We present two formulae to calculate quantum discord, the
first relating to the original entropic definition and the second to a recently
proposed geometric distance measure which leads to an analytical formulation.
The tracing over the qubit in the entropic calculation is reduced to a very
simple prescription. And, when the d-dimensional system is a so-called X state,
the density matrix having non-zero elements only along the diagonal and
anti-diagonal so as to appear visually like the letter X, the entropic
calculation can be carried out analytically. Such states of the full bipartite
qubit-qudit system may be named "extended X states", whose density matrix is
built of four block matrices, each visually appearing as an X. The optimization
involved in the entropic calculation is generally over two parameters, reducing
to one for many cases, and avoided altogether for an overwhelmingly large set
of density matrices as our numerical investigations demonstrate. Our results
also apply to states of a N-qubit system, where "extended X states" consist of
(2^(N+2) - 1) states, larger in number than the (2^(N+1) - 1) of X states of N
qubits. While these are still smaller than the total number (2^(2N) - 1) of
states of N qubits, the number of parameters involved is nevertheless large. In
the case of N = 2, they encompass the entire 15-dimensional parameter space,
that is, the extended X states for N = 2 represent the full qubit-qubit system.Comment: 6 pages, 1 figur
An adaptation of meaning-centered psychotherapy integrating "essential care": A pilot study
Introduction There is a growing interest in the emotional state of cancer patients. The main objective of this pilot study is to assess the feasibility, acceptability, and preliminary efficacy of Meaning-Centered Psychotherapy and Essential Care (MCP-EC) in patients with advanced cancer compared with usual psychological support. We define "Essential Care"as the promotion of patient care and self-care through the recall of good care experiences and discussion of the concepts: responsibility, self-compassion, kindness, and attitude. Method Pilot, single-center, and prospective study of 30 patients with advanced cancer and emotional distress. Our adaptation consisted in three session Meaning-Centered Psychotherapy-Palliative Care, plus a fourth session named "Essential Care". The study was carried out in two phases. First, 20 patients were randomized to one of the two arms: individual MCP-EC (experimental, n = 10) or usual psychological supportive (control, n = 10). In a second phase, 10 patients were assigned consecutively to Group MCP-EC (n = 10). All patients were evaluated at baseline (pre-) and post-intervention with questionnaires for sociodemographic data and clinical scales. Results Nineteen patients completed the 4 sessions of MCP-EC, 9 individual format and 10 group format. Usual supportive intervention was delivered to 10 control patients. Total 28 patients completed pre- and post-treatment evaluations. There were no pre- vs. post-differences in the evaluations of the control group. In the experimental group, significant pre- vs. post-differences were found in EQ-5D-3L, HADS, FACIT, DM, HAI, SCS-SF, and TD questionnaires. These results indicated that MCP-EC reduced anxiety and depression symptoms, hopelessness, demoralization, as well as increased spiritual well-being and sense of meaning. Participants were satisfied and found the MCP-EC intervention positively. Conclusions This pilot study suggests that the MCP-EC has feasibility, acceptability, and preliminary efficacy reducing the emotional distress in advanced cancer patients. Larger studies are warranted to clarify the strengths and limitations of this psychotherapy. © The Author(s), 2021. Published by Cambridge University Press
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