158 research outputs found
Design of ternary signals for MIMO identification in the presence of noise and nonlinear distortion
A new approach to designing sets of ternary periodic signals with different periods for multi-input multi-output system identification is described. The signals are pseudo-random signals with uniform nonzero harmonics, generated from Galois field GF(q), where q is a prime or a power of a prime. The signals are designed to be uncorrelated, so that effects of different inputs can be easily decoupled. However, correlated harmonics can be included if necessary, for applications in the identification of ill-conditioned processes. A design table is given for q les 31. An example is presented for the design of five uncorrelated signals with a common period N = 168 . Three of these signals are applied to identify the transfer function matrix as well as the singular values of a simulated distillation column. Results obtained are compared with those achieved using two alternative methods
Role of DNA methylation in head and neck cancer
Head and neck cancer (HNC) is a heterogenous and complex entity including diverse anatomical sites and a variety of tumor types displaying unique characteristics and different etilogies. Both environmental and genetic factors play a role in the development of the disease, but the underlying mechanism is still far from clear. Previous studies suggest that alterations in the genes acting in cellular signal pathways may contribute to head and neck carcinogenesis. In cancer, DNA methylation patterns display specific aberrations even in the early and precancerous stages and may confer susceptibility to further genetic or epigenetic changes. Silencing of the genes by hypermethylation or induction of oncogenes by promoter hypomethylation are frequent mechanisms in different types of cancer and achieve increasing diagnostic and therapeutic importance since the changes are reversible. Therefore, methylation analysis may provide promising clinical applications, including the development of new biomarkers and prediction of the therapeutic response or prognosis. In this review, we aimed to analyze the available information indicating a role for the epigenetic changes in HNC
Search for an invisible muon philic scalar or vector via decay at BESIII
A light scalar or vector particles have been introduced as a
possible explanation for the anomaly and dark matter phenomena.
Using \jpsi events collected by the BESIII
detector, we search for a light muon philic scalar or vector in
the processes with invisible decays. No
obvious signal is found, and the upper limits on the coupling
between the muon and the particles are set to be between
and for the mass in the range
of ~MeV at 90 confidence level.Comment: 9 pages 7 figure
First Observation of a Three-Resonance Structure in {non-open} Charm Hadrons
We report the measurement of the cross sections for
{nOCH} (nOCH stands for non-open charm hadrons) with
improved precision at center-of-mass energies from 3.645 to 3.871 GeV. We
observe for the first time a three-resonance structure in the energy-dependent
lineshape of the cross sections, which are , and with significances of ,
, and , respectively. The is observed
for the first time. We found two solutions in analysis of the cross sections.
For solution I [solution II], we measure the mass, the total width and the
product of electronic width and nOCH decay branching fraction to be [] MeV/, [] MeV, and [] eV for the , respectively. In addition, we
measure the branching fractions {nOCH} for the first time, and {nOCH}. Moreover, we determine the open-charm (OC) branching fraction
{OC}, which supports the interpretation of as an OC pair molecular state, but contained a simple four-quark state
component. The first uncertainties are from fits to the cross sections, and the
second are systematic
Measurement of the cross sections from 2.000 to 3.080 GeV
Based on collision data collected at center-of-mass energies
from 2.000 to 3.080 GeV by the BESIII detector at the BEPCII collider, a
partial wave analysis is performed for the process . The results allow the Born cross sections of the process
, as well as its subprocesses
and to be
measured. The Born cross sections for are consistent with previous measurements by BaBar and SND,
but with substantially improved precision. The Born cross section lineshape of
the process is consistent with a vector
meson state around 2.2 GeV with a statistical significance of 3.2. A
Breit-Wigner fit determines its mass as
and its width as
, where the first uncertainties are
statistical and the second ones are systematic, respectively
Study of at from 2.00 to 3.08 GeV at BESIII
With the data samples taken at center-of-mass energies from 2.00 to 3.08 GeV
with the BESIII detector at the BEPCII collider, a partial wave analysis on the
process is performed. The Born
cross sections for and its
intermediate processes and are
measured as functions of . The results for
are consistent with previous
results measured with the initial state radiation method within one standard
deviation, and improve the uncertainty by a factor of ten. By fitting the line
shapes of the Born cross sections for the and
, a structure with mass and
width is observed with a significance of
, where the first uncertainties are statistical and the second ones
are systematic. This structure can be intepreteted as an excited
state
A coupled-channel analysis of the lineshape with BESIII data
We perform a study of the lineshape using the data samples of
, and collected with the BESIII detector. The effects of the coupled-channels
and the off-shell are included in the parameterization of the
lineshape. The lineshape mass parameter is obtained to be MeV. Two poles are found on the first and second Riemann
sheets corresponding to the branch cut. The pole location on
the first sheet is much closer to the threshold than the
other, and is determined to be MeV above the
threshold with an imaginary part
MeV
Amplitude analysis and branching fraction measurement of the decay
Using 2.93 of collision data collected with the
BESIII detector at the center-of-mass energy 3.773\,GeV, we perform the first
amplitude analysis of the decay and determine the
relative magnitudes and phases of different intermediate processes. The
absolute branching fraction of is measured to be
. The dominant intermediate
processes are and , with branching fractions of and , respectively
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