499 research outputs found
Computer Technology in Network Society
With the continuous development of society, computer technology hinders all aspects of social life, and information shows an inseparable relationship. With the help of reasonable use of computer technology, the speed of information processing is significantly improved, and the transmission and identification of information are further promoted. The continuous advancement of computer technology has contributed to the rapid expansion of its influence. From the objective point of view, the computer technology in play its advantages at the same time, once the use of unscientific, will also form a certain negative impact. Therefore, it is necessary to discuss the computer technology from many angles
Well-posedness of the discrete nonlinear Schr\"odinger equations and the Klein-Gordon equations
The primary objective of this paper is to investigate the well-posedness
theories associated with the discrete nonlinear Schr\"odinger equation and
Klein-Gordon equation. These theories encompass both local and global
well-posedness, as well as the existence of blowing-up solutions for large and
irregular initial data.
The main results of this paper presented in this paper can be summarized as
follows:
1. Discrete Nonlinear Schr\"odinger Equation: We establish global
well-posedness in spaces for all , regardless of
whether it is in the defocusing or focusing cases.
2. Discrete Klein-Gordon Equation (including Wave Equation): We demonstrate
local well-posedness in spaces for all .
Furthermore, in the defocusing case, we establish global well-posedness in
spaces for any . In contrast, in the focusing
case, we show that solutions with negative energy blow up within a finite time
A Chemical Study of Nine Star-forming Regions with Evidence of Infall Motion
The study of the physical and chemical properties of gas infall motion in the
molecular clumps helps us understand the initial stages of star formation. We
used the FTS wide-sideband mode of the IRAM 30-m telescope to observe nine
infall sources with significant double peaked blue line profile. The
observation frequency range are 83.7 - 91.5 GHz and 99.4 - 107.2 GHz. We have
obtained numbers of molecular line data. Using XCLASS, a total of 7 to 27
different molecules and isotopic transition lines have been identified in these
nine sources, including carbon chain molecules such as CCH, c-C3H2 and HC3N.
According to the radiation transfer model, we estimated the rotation
temperatures and column densities of these sources. Chemical simulations
adopting a physical model of HMSFRs are used to fit the observed molecular
abundances. The comparison shows that most sources are in the early HMPO stage,
with the inner temperature around several ten K
Hardware-in-the-Loop Simulation for Evaluating Communication Impacts on the Wireless-Network-Controlled Robots
More and more robot automation applications have changed to wireless
communication, and network performance has a growing impact on robotic systems.
This study proposes a hardware-in-the-loop (HiL) simulation methodology for
connecting the simulated robot platform to real network devices. This project
seeks to provide robotic engineers and researchers with the capability to
experiment without heavily modifying the original controller and get more
realistic test results that correlate with actual network conditions. We
deployed this HiL simulation system in two common cases for
wireless-network-controlled robotic applications: (1) safe multi-robot
coordination for mobile robots, and (2) human-motion-based teleoperation for
manipulators. The HiL simulation system is deployed and tested under various
network conditions in all circumstances. The experiment results are analyzed
and compared with the previous simulation methods, demonstrating that the
proposed HiL simulation methodology can identify a more reliable communication
impact on robot systems.Comment: 6 pages, 11 figures, to appear in 48th Annual Conference of the
Industrial Electronics Society IECON 2022 Conferenc
Hamiltonian Switching Control of Noisy Bipartite Qubit Systems
We develop a Hamiltonian switching ansatz for bipartite control that is
inspired by the Quantum Approximate Optimization Algorithm (QAOA), to mitigate
environmental noise on qubits. We illustrate the approach with application to
the protection of quantum gates performed on i) a central spin qubit coupling
to bath spins through isotropic Heisenberg interactions, ii) superconducting
transmon qubits coupling to environmental two-level-systems (TLS) through
dipole-dipole interactions, and iii) qubits coupled to both TLS and a Lindblad
bath. The control field is classical and acts only on the system qubits. We use
reinforcement learning with policy gradient (PG) to optimize the Hamiltonian
switching control protocols, using a fidelity objective defined with respect to
specific target quantum gates. We use this approach to demonstrate effective
suppression of both coherent and dissipative noise, with numerical studies
achieving target gate implementations with fidelities over 0.9999 (four nines)
in the majority of our test cases and showing improvement beyond this to values
of 0.999999999 (nine nines) upon a subsequent optimization by Gradient Ascent
Pulse Engineering (GRAPE). We analyze how the control depth, total evolution
time, number of environmental TLS, and choice of optimization method affect the
fidelity achieved by the optimal protocols and reveal some critical behaviors
of bipartite control of quantum gates.Comment: 22 pages, 9 figures, 4 tables. Appendices: 7 pages, 2 figures, 1
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