6,809 research outputs found
ZOOpt: Toolbox for Derivative-Free Optimization
Recent advances of derivative-free optimization allow efficient approximating
the global optimal solutions of sophisticated functions, such as functions with
many local optima, non-differentiable and non-continuous functions. This
article describes the ZOOpt (https://github.com/eyounx/ZOOpt) toolbox that
provides efficient derivative-free solvers and are designed easy to use. ZOOpt
provides a Python package for single-thread optimization, and a light-weighted
distributed version with the help of the Julia language for Python described
functions. ZOOpt toolbox particularly focuses on optimization problems in
machine learning, addressing high-dimensional, noisy, and large-scale problems.
The toolbox is being maintained toward ready-to-use tool in real-world machine
learning tasks
Numerical investigation of airborne infection in naturally ventilated hospital wards with central-corridor type
Cramer-Rao Bound Optimization for Active RIS-Empowered ISAC Systems
Integrated sensing and communication (ISAC), which simultaneously performs
sensing and communication functions using the same frequency band and hardware
platform, has emerged as a promising technology for future wireless systems.
However, the weak echo signal received by the low-sensitivity ISAC receiver
severely limits the sensing performance. Active reconfigurable intelligent
surface (RIS) has become a prospective solution by situationally manipulating
the wireless propagations and amplifying the signals. In this paper, we
investigate the deployment of active RIS-empowered ISAC systems to enhance
radar echo signal quality as well as communication performance. In particular,
we focus on the joint design of the base station (BS) transmit precoding and
the active RIS reflection beamforming to optimize the parameter estimation
performance in terms of Cramer-Rao bound (CRB) subject to the service users'
signal-to-interference-plus-noise ratio (SINR) requirements. An efficient
algorithm based on block coordinate descent (BCD), semidefinite relaxation
(SDR), and majorization-minimization (MM) is proposed to solve the formulated
challenging non-convex problem. Finally, simulation results validate the
effectiveness of the developed algorithm and the potential of employing active
RIS in ISAC systems to enhance direct-of-arrival (DoA) estimation performance.Comment: 30 pages, 9 figures, submitted to IEEE journa
Predicted and decay modes of the charmoniumlike
In this work, we predict the light hadronic decay channels
and when treating the
as a vector charmonium state. By the hadronic loop mechanism, the
branching ratios of the and
processes are calculated. In addition, we discuss the possibility of carrying
out the search for the signal of the through
and channels from the annihilation. Assuming
exist in and channel, we
also present the time-like electromagnetic form factors (EMFFs) at
.Comment: 8 pages, 9 figures and 2 table
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