9,105 research outputs found
A Dual Hesitant Fuzzy Multigranulation Rough Set over Two-Universe Model for Medical Diagnoses
In medical science, disease diagnosis is one of the difficult tasks for medical experts who are confronted with challenges in dealing with a lot of uncertain medical information. And different medical experts might express their own thought about the medical knowledge base which slightly differs from other medical experts. Thus, to solve the problems of uncertain data analysis and group decision making in disease diagnoses, we propose a new rough set model called dual hesitant fuzzy multigranulation rough set over two universes by combining the dual hesitant fuzzy set and multigranulation rough set theories. In the framework of our study, both the definition and some basic properties of the proposed model are presented. Finally, we give a general approach which is applied to a decision making problem in disease diagnoses, and the effectiveness of the approach is demonstrated by a numerical example
High brightness fully coherent X-ray amplifier seeded by a free-electron laser oscillator
X-ray free-electron laser oscillator (XFELO) is expected to be a cutting edge
tool for fully coherent X-ray laser generation, and undulator taper technique
is well-known for considerably increasing the efficiency of free-electron
lasers (FELs). In order to combine the advantages of these two schemes, FEL
amplifier seeded by XFELO is proposed by simply using a chirped electron beam.
With the right choice of the beam parameters, the bunch tail is within the gain
bandwidth of XFELO, and lase to saturation, which will be served as a seeding
for further amplification. Meanwhile, the bunch head which is outside the gain
bandwidth of XFELO, is preserved and used in the following FEL amplifier. It is
found that the natural "double-horn" beam current as well as residual energy
chirp from chicane compressor are quite suitable for the new scheme. Inheriting
the advantages from XFELO seeding and undulator tapering, it is feasible to
generate nearly terawatt level, fully coherent X-ray pulses with unprecedented
shot-to-shot stability, which might open up new scientific opportunities in
various research fields.Comment: 8 pages, 8 figure
QCD radiative correction to color-octet inclusive production at B Factories
In nonrelativistic Quantum Chromodynamics (NRQCD), we study the
next-to-leading order (NLO) QCD radiative correction to the color-octet
inclusive production at B Factories. Compared with the leading-order
(LO) result, the NLO QCD corrections are found to enhance the short-distance
coefficients in the color-octet production by a factor of about 1.9. Moreover, the
peak at the endpoint in the energy distribution predicted at LO can be
smeared by the NLO corrections, but the major color-octet contribution still
comes from the large energy region of . By fitting the latest data of
observed by Belle, we
find that the values of color-octet matrix elements are much smaller than
expected earlier by using the naive velocity scaling rules or extracted from
fitting experimental data with LO calculations. As the most stringent
constraint by setting the color-singlet contribution to be zero in
, we get an upper limit of the
color-octet matrix element, at NLO in .Comment: 18 pages, 8 figure
- β¦