872 research outputs found
Propagation of singularities for Schr\"odinger equations with modestly long range type potentials
In a previous paper by the second author, we discussed a characterization of
the microlocal singularities for solutions to Schr\"odinger equations with long
range type perturbations, using solutions to a Hamilton-Jacobi equation. In
this paper we show that we may use Dollard type approximate solutions to the
Hamilton-Jacobi equation if the perturbation satisfies somewhat stronger
conditions. As applications, we describe the propagation of microlocal
singularities for when the potential is asymptotically
homogeneous as , where is our Schr\"odinger operator, and
is the free Schr\"odinger operator, i.e., . We
show shifts the wave front set if the potential is
asymptotically homogeneous of order 1, whereas is smoothing
if is asymptotically homogenous of order
Deterministic photon-photon (SWAP)^{1/2} gate using a lambda system
We theoretically present a method to realize a deterministic photon-photon
(SWAP)^{1/2} gate using a three-level lambda system interacting with single
photons in reflection geometry. The lambda system is used completely passively
as a temporary memory for a photonic qubit; the initial state of the lambda
system may be arbitrary, and active control by auxiliary fields is unnecessary
throughout the gate operations. These distinct merits make this entangling gate
suitable for deterministic and scalable quantum computation.Comment: 7 pages, 4 figure
階層ベイズモデルを利用した実行可能な健康改善プランを提案するAI技術の開発
京都大学新制・課程博士博士(人間健康科学)甲第24539号人健博第110号新制||人健||8(附属図書館)京都大学大学院医学研究科人間健康科学系専攻(主査)教授 木下 彩栄, 教授 中尾 恵, 教授 中山 健夫学位規則第4条第1項該当Doctor of Human Health SciencesKyoto UniversityDFA
Application of Quantum Annealing to Nurse Scheduling Problem
Quantum annealing is a promising heuristic method to solve combinatorial
optimization problems, and efforts to quantify performance on real-world
problems provide insights into how this approach may be best used in practice.
We investigate the empirical performance of quantum annealing to solve the
Nurse Scheduling Problem (NSP) with hard constraints using the D-Wave 2000Q
quantum annealing device. NSP seeks the optimal assignment for a set of nurses
to shifts under an accompanying set of constraints on schedule and personnel.
After reducing NSP to a novel Ising-type Hamiltonian, we evaluate the solution
quality obtained from the D-Wave 2000Q against the constraint requirements as
well as the diversity of solutions. For the test problems explored here, our
results indicate that quantum annealing recovers satisfying solutions for NSP
and suggests the heuristic method is sufficient for practical use. Moreover, we
observe that solution quality can be greatly improved through the use of
reverse annealing, in which it is possible to refine a returned results by
using the annealing process a second time. We compare the performance NSP using
both forward and reverse annealing methods and describe how these approach
might be used in practice.Comment: 20 pages, 13 figure
Anticancer and antimetastatic effects of cordycepin, an active component of Cordyceps sinensis
AbstractCordyceps sinensis, a fungus that parasitizes on the larva of Lepidoptera, has been used as a valued traditional Chinese medicine. We investigated the effects of water extracts of Cordyceps sinensis (WECS), and particularly focused on its anticancer and antimetastatic actions. Based on in vitro studies, we report that WECS showed an anticancer action, and this action was antagonized by an adenosine A3 receptor antagonist. Moreover, this anticancer action of WECS was promoted by an adenosine deaminase inhibitor. These results suggest that one of the components of WECS with an anticancer action might be an adenosine or its derivatives. Therefore, we focused on cordycepin (3′-deoxyadenosine) as one of the active ingredients of WECS. According to our experiments, cordycepin showed an anticancer effect through the stimulation of adenosine A3 receptor, followed by glycogen synthase kinase (GSK)-3β activation and cyclin D1 suppression. Cordycepin also showed an antimetastatic action through inhibiting platelet aggregation induced by cancer cells and suppressing the invasiveness of cancer cells via inhibiting the activity of matrix metalloproteinase (MMP)-2 and MMP-9, and accelerating the secretion of tissue inhibitor of metalloproteinase (TIMP)-1 and TIMP-2 from cancer cells. In conclusion, cordycepin, an active component of WECS, might be a candidate anticancer and antimetastatic agent
Broadband coherent Raman scattering spectroscopy at 50,000,000 spectra/s
Raman scattering spectroscopy is widely used as an analytical technique in
various fields, but its measurement process tends to be slow due to the low
scattering cross-section. In the last decade, various broadband coherent Raman
scattering spectroscopy techniques have been developed to address this
limitation, achieving a measurement rate of about 100 kSpectra/s. Here, we
present a significantly increased measurement rate of 50 MSpectra/s, which is
500 times higher than the previous state-of-the-art, by developing time-stretch
coherent Raman scattering spectroscopy. Our newly-developed system, based on a
mode-locked Yb fiber laser, enables highly-efficient broadband excitation of
molecular vibrations via impulsive stimulated Raman scattering with an
ultrashort femtosecond pulse and sensitive time-stretch detection with a
picosecond probe pulse at a high repetition rate of the laser. As a
proof-of-concept demonstration, we measure broadband coherent Stokes Raman
scattering spectra of organic compounds covering the molecular fingerprint
region from 200 to 1,200 cm-1. This high-speed broadband vibrational
spectroscopy technique holds promise for unprecedented measurements of
sub-microsecond dynamics of irreversible phenomena and extremely
high-throughput measurements
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