440 research outputs found
Contribution of animal source foods in improving diet quality for children in the developing world
Carbonized blood deposited on fibres during 810, 940 and 1,470 nm endovenous laser ablation: thickness and absorption by optical coherence tomography
Steady and Stable: Numerical Investigations of Nonlinear Partial Differential Equations
Excerpt: Mathematics is a language which can describe patterns in everyday life as well as abstract concepts existing only in our minds. Patterns exist in data, functions, and sets constructed around a common theme, but the most tangible patterns are visual. Visual demonstrations can help undergraduate students connect to abstract concepts in advanced mathematical courses. The study of partial differential equations, in particular, benefits from numerical analysis and simulation
Quantifying Entanglement Production of Quantum Operations
The problem of entanglement produced by an arbitrary operator is formulated
and a related measure of entanglement production is introduced. This measure of
entanglement production satisfies all properties natural for such a
characteristic. A particular case is the entanglement produced by a density
operator or a density matrix. The suggested measure is valid for operations
over pure states as well as over mixed states, for equilibrium as well as
nonequilibrium processes. Systems of arbitrary nature can be treated, described
either by field operators, spin operators, or any other kind of operators,
which is realized by constructing generalized density matrices. The interplay
between entanglement production and phase transitions in statistical systems is
analysed by the examples of Bose-Einstein condensation, superconducting
transition, and magnetic transitions. The relation between the measure of
entanglement production and order indices is analysed.Comment: 20 pages, Revte
Limitations to sharing entanglement
We discuss limitations to sharing entanglement known as monogamy of
entanglement. Our pedagogical approach commences with simple examples of
limited entanglement sharing for pure three-qubit states and progresses to the
more general case of mixed-state monogamy relations with multiple qudits.Comment: Pedagogical review article on monogamy and polygamy of entanglemen
Classical Logical versus Quantum Conceptual Thought: Examples in Economics, Decision theory and Concept Theory
Inspired by a quantum mechanical formalism to model concepts and their
disjunctions and conjunctions, we put forward in this paper a specific
hypothesis. Namely that within human thought two superposed layers can be
distinguished: (i) a layer given form by an underlying classical deterministic
process, incorporating essentially logical thought and its indeterministic
version modeled by classical probability theory; (ii) a layer given form under
influence of the totality of the surrounding conceptual landscape, where the
different concepts figure as individual entities rather than (logical)
combinations of others, with measurable quantities such as 'typicality',
'membership', 'representativeness', 'similarity', 'applicability', 'preference'
or 'utility' carrying the influences. We call the process in this second layer
'quantum conceptual thought', which is indeterministic in essence, and contains
holistic aspects, but is equally well, although very differently, organized
than logical thought. A substantial part of the 'quantum conceptual thought
process' can be modeled by quantum mechanical probabilistic and mathematical
structures. We consider examples of three specific domains of research where
the effects of the presence of quantum conceptual thought and its deviations
from classical logical thought have been noticed and studied, i.e. economics,
decision theory, and concept theories and which provide experimental evidence
for our hypothesis.Comment: 14 page
Time-of-arrival distributions from position-momentum and energy-time joint measurements
The position-momentum quasi-distribution obtained from an Arthurs and Kelly
joint measurement model is used to obtain indirectly an ``operational''
time-of-arrival (TOA) distribution following a quantization procedure proposed
by Kocha\'nski and W\'odkiewicz [Phys. Rev. A 60, 2689 (1999)]. This TOA
distribution is not time covariant. The procedure is generalized by using other
phase-space quasi-distributions, and sufficient conditions are provided for
time covariance that limit the possible phase-space quasi-distributions
essentially to the Wigner function, which, however, provides a non-positive TOA
quasi-distribution. These problems are remedied with a different quantization
procedure which, on the other hand, does not guarantee normalization. Finally
an Arthurs and Kelly measurement model for TOA and energy (valid also for
arbitrary conjugate variables when one of the variables is bounded from below)
is worked out. The marginal TOA distribution so obtained, a distorted version
of Kijowski's distribution, is time covariant, positive, and normalized
Spiky strings and giant magnons on S5
Recently, classical solutions for strings moving in AdS5 x S5 have played an
important role in understanding the AdS/CFT correspondence. A large set of them
were shown to follow from an ansatz that reduces the solution of the string
equations of motion to the study of a well-known integrable 1-d system known as
the Neumann-Rosochatius (NR) system. However, other simple solutions such as
spiky strings or giant magnons in S5 were not included in the NR ansatz. We
show that, when considered in the conformal gauge, these solutions can be also
accomodated by a version of the NR-system. This allows us to describe in detail
a giant magnon solution with two additional angular momenta and show that it
can be interpreted as a superposition of two magnons moving with the same
speed. In addition, we consider the spin chain side and describe the
corresponding state as that of two bound states in the infinite SU(3) spin
chain. We construct the Bethe ansatz wave function for such bound state.Comment: 33 pages, LaTeX, 2 figures. v2: minor corrections, v3: minor
corrections, figures enlarge
外国語を教えるということ(SOLAC発足10周年記念特別寄稿エッセー)
Contains fulltext :
153048.pdf (publisher's version ) (Closed access)BACKGROUND: To describe functioning and health of lymphedema patients and to identify their most common problems using the International Classification of Functioning, Disability and Health (ICF) as part of the preparatory studies for the development of ICF Core Sets for lymphedema. METHODS: Cross-sectional study in a population of lymphedema patients (n = 200), undergoing treatment in a Dutch lymphedema-specialized hospital. The second-level categories of the ICF were used to collect information on patients' problems in daily functioning. RESULTS: The mean age of the study group was 56 years (22-84). In total 78.5% of the patients were female. The most frequent mentioned items were: In the Body Functions component: muscle power and mobility of joints, in the Activities and Participation component: doing housework, and changing and maintaining a body position, in the Environmental Factors: Health professionals, who can act as both facilitators and barriers. Interestingly, patients assessed their health more positively than health professionals do. CONCLUSION: By using the ICF, a considerable part of the broad spectrum of problems in functioning of lymphedema patients was reported
Microscopic description of d-wave superconductivity by Van Hove nesting in the Hubbard model
We devise a computational approach to the Hubbard model that captures the
strong coupling dynamics arising when the Fermi level is at a Van Hove
singularity in the density of states. We rely on an approximate degeneracy
among the many-body states accounting for the main instabilities of the system
(antiferromagnetism, d-wave superconductivity). The Fermi line turns out to be
deformed in a manner consistent with the pinning of the Fermi level to the Van
Hove singularity. For a doping rate , the ground state is
characterized by d-wave symmetry, quasiparticles gapped only at the
saddle-points of the band, and a large peak at zero momentum in the d-wave
pairing correlations.Comment: 4 pages, 2 Postscript figure
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