15,137 research outputs found
Determination of mixing angle through decays
We study decays, the quark content of
and the mixing angle of and . We calculate not only the
factorizable contribution in QCD facorization scheme but also the
nonfactorizable hard spectator corrections in QCDF and pQCD approach. We get
consistent result with the experimental data of and
predict the branching ratio of . We suggest two ways
to determine mixing angle . Using the experimental
measured branching ratio of , we can get the
mixing angle with some theoretical uncertainties. We
suggest another way to determine mixing angle using both
of experimental measured decay branching ratios to avoid theoretical uncertainties.Comment: arXiv admin note: substantial text overlap with arXiv:0707.263
Designing the Right IT Services for the Bottom of the Pyramid
This article introduces ways to create proper IT services which can help organizations serve the emerging rural markets. The research is based on a two-year action research project which derives a framework for building IT services for the low-income consumers in the rural area of China. The framework is proposed to understand the characteristics that the consumers in the rural area use the IT services, especially in China. The framework helps IT companies and governmental agencies design and improve the IT services they provided to the emerging market
Online Tensor Learning: Computational and Statistical Trade-offs, Adaptivity and Optimal Regret
We investigate a generalized framework for estimating latent low-rank tensors
in an online setting, encompassing both linear and generalized linear models.
This framework offers a flexible approach for handling continuous or
categorical variables. Additionally, we investigate two specific applications:
online tensor completion and online binary tensor learning. To address these
challenges, we propose the online Riemannian gradient descent algorithm, which
demonstrates linear convergence and the ability to recover the low-rank
component under appropriate conditions in all applications. Furthermore, we
establish a precise entry-wise error bound for online tensor completion.
Notably, our work represents the first attempt to incorporate noise in the
online low-rank tensor recovery task. Intriguingly, we observe a surprising
trade-off between computational and statistical aspects in the presence of
noise. Increasing the step size accelerates convergence but leads to higher
statistical error, whereas a smaller step size yields a statistically optimal
estimator at the expense of slower convergence. Moreover, we conduct regret
analysis for online tensor regression. Under the fixed step size regime, a
fascinating trilemma concerning the convergence rate, statistical error rate,
and regret is observed. With an optimal choice of step size we achieve an
optimal regret of . Furthermore, we extend our analysis to the
adaptive setting where the horizon T is unknown. In this case, we demonstrate
that by employing different step sizes, we can attain a statistically optimal
error rate along with a regret of . To validate our theoretical
claims, we provide numerical results that corroborate our findings and support
our assertions
MiR-1/133 attenuates cardiomyocyte apoptosis and electrical remodeling in mice with viral myocarditis
Background: The role of miR-1 and miR-133 in regulating the expression of potassium and calcium ion channels, and mediating cardiomyocyte apoptosis in mice with viral myocarditis (VMC) is investigated herein.
Methods: Male Balb/c mice were randomly divided into groups: control group, VMC group, VMC + miR-1/133 mimics group, or VMC + miR-1/133 negative control (NC) group. VMC was induced with coxsackievirus B3 (CVB3). MiR-1/133 mimics ameliorated cardiac dysfunction in VMC mice and was compared to the VMC+NC group.
Results: Hematoxylin and eosin staining showed a well-arranged myocardium without inflammatory cell infiltration in the myocardial matrix of the control group. However, in the VMC and VMC+NC groups, the myocardium was disorganized and swollen with necrosis, and the myocardial matrix was infiltrated with inflammatory cells. These changes were alleviated by miR-1/133 mimics. TUNEL staining revealed decreased cardiomyocyte apoptosis in the VMC + miR-1/133 mimics group compared with the VMC group. In addition, miR-1/133 mimics up-regulated the expression of miR-1 and miR-133, the potassium channel genes Kcnd2 and Kcnj2, as well as Bcl-2, and down-regulated the expression of the potassium channel suppressor gene Irx5, L-type calcium channel subunit gene a1c (Cacna1c), Bax, and caspase-9 in the myocardium of VMC mice. MiR-1/133 also up-regulated the protein levels of Kv4.2 and Kir2.1, and down-regulated the expression of CaV1.2 in the myocardium of VMC mice.
Conclusions: MiR-1 and miR-133 decreased cardiomyocyte apoptosis by mediating the expression of apoptosis-related genes in the hearts of VMC mice
Scale-based surface understanding using diffusion smoothing
The research discussed in this thesis is concerned with surface understanding from the
viewpoint of recognition-oriented, scale-related processing based on surface curvatures and
diffusion smoothing. Four problems below high level visual processing are investigated:
1) 3-dimensional data smoothing using a diffusion process;
2) Behaviour of shape features across multiple scales,
3) Surface segmentation over multiple scales; and
4) Symbolic description of surface features at multiple scales.
In this thesis, the noisy data smoothing problem is treated mathematically as a boundary
value problem of the diffusion equation instead of the well-known Gaussian convolution,
In such a way, it provides a theoretical basis to uniformly interpret the interrelationships
amongst diffusion smoothing, Gaussian smoothing, repeated averaging and
spline smoothing. It also leads to solving the problem with a numerical scheme of unconditional
stability, which efficiently reduces the computational complexity and preserves the
signs of curvatures along the surface boundaries.
Surface shapes are classified into eight types using the combinations of the signs of
the Gaussian curvature K and mean curvature H, both of which change at different scale
levels. Behaviour of surface shape features over multiple scale levels is discussed in
terms of the stability of large shape features, the creation, remaining and fading of small
shape features, the interaction between large and small features and the structure of
behaviour of the nested shape features in the KH sign image. It provides a guidance for
tracking the movement of shape features from fine to large scales and for setting up a surface
shape description accordingly.
A smoothed surface is partitioned into a set of regions based on curvature sign
homogeneity. Surface segmentation is posed as a problem of approximating a surface up
to the degree of Gaussian and mean curvature signs using the depth data alone How to
obtain feasible solutions of this under-determined problem is discussed, which includes the
surface curvature sign preservation, the reason that a sculptured surface can be segmented
with the KH sign image alone and the selection of basis functions of surface fitting for
obtaining the KH sign image or for region growing.
A symbolic description of the segmented surface is set up at each scale level. It is
composed of a dual graph and a geometrical property list for the segmented surface. The
graph describes the adjacency and connectivity among different patches as the
topological-invariant properties that allow some object's flexibility, whilst the geometrical
property list is added to the graph as constraints that reduce uncertainty. With this organisation,
a tower-like surface representation is obtained by tracking the movement of
significant features of the segmented surface through different scale levels, from which a
stable description can be extracted for inexact matching during object recognition
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