802 research outputs found
Observation of sub-Doppler absorption in the /Lambda-type three-level Doppler-broadened cesium system
Thanks to the atomic coherence in coupling laser driven atomic system,
sub-Doppler absorption has been observed in Doppler-broadened cesium vapor cell
via the /Lambda-type three-level scheme. The linewidth of the sub-Doppler
absorption peak become narrower while the frequency detuning of coupling laser
increases. The results are in agreement with the theoretical prediction by G.
Vemuri et al.[PRA,Vol.53(1996) p.2842].Comment: 12 pages, 5 figures, to appear on Applied Physics
Perturbations of Dirac operators
We study general conditions under which the computations of the index of a
perturbed Dirac operator localize to the singular set of the
bundle endomorphism in the semi-classical limit . We show how
to use Witten's method to compute the index of by doing a combinatorial
computation involving local data at the nondegenerate singular points of the
operator . In particular, we provide examples of novel deformations of the
de Rham operator to establish new results relating the Euler characteristic of
a spin manifold to maps between its even and odd spinor bundles. The
paper contains a list of the current literature on the subject.Comment: 34 pages, improved results, new applications, literature list update
Brief Report of an Artificial Rearing Method for Paragus quadri-fasciatus Meigen
The four-striped small syrphid fly, Paragus quadri-fasciatus Meigen, is one important kind of natural enemy of aphids. Since 1983 we have studied the utilization of this natural enemy. We selected perennial grasses (of two to three years life span), which host aphids. In the first year we planted the above-mentioned grasses and in the second year we raised the syrphid fly. Details of the method are described as follows.Originating text in Chinese.Citation: Gao, Junfeng, Zhang, Li, Zhang, Shubin, Qin, Bo. (1992). Brief Report of an Artificial Rearing Method for Paragus quadri-fasciatus Meigen. Natural Enemies of Insects, 14(4), 188-190
Sign-changing solutions for a Schrödinger-Kirchhoff-Poisson system with 4-sublinear growth nonlinearity
In this paper we consider the following Schrödinger–Kirchhoff–Poisson-type system where Ω is a bounded smooth domain of R3 , a > 0, b ≥ 0 are constants and λ is a positive parameter. Under suitable conditions on Q(x) and combining the method of invariant sets of descending flow, we establish the existence and multiplicity of signchanging solutions to this problem for the case that 2 < p < 4 as λ sufficiently small. Furthermore, for λ = 1 and the above assumptions on Q(x), we obtain the same conclusions with 2 < p < 12 5
DynLight: Realize dynamic phase duration with multi-level traffic signal control
Adopting reinforcement learning (RL) for traffic signal control (TSC) is
increasingly popular, and RL has become a promising solution for traffic signal
control. However, several challenges still need to be overcome. Firstly, most
RL methods use fixed action duration and select the green phase for the next
state, which makes the phase duration less dynamic and flexible. Secondly, the
phase sequence of RL methods can be arbitrary, affecting the real-world
deployment which may require a cyclical phase structure. Lastly, the average
travel time and throughput are not fair metrics to evaluate TSC performance. To
address these challenges, we propose a multi-level traffic signal control
framework, DynLight, which uses an optimization method Max-QueueLength (M-QL)
to determine the phase and uses a deep Q-network to determine the duration of
the corresponding phase. Based on DynLight, we further propose DynLight-C which
adopts a well-trained deep Q-network of DynLight and replace M-QL with a
cyclical control policy that actuates a set of phases in fixed cyclical order
to realize cyclical phase structure. Comprehensive experiments on multiple
real-world datasets demonstrate that DynLight achieves a new state-of-the-art.
Furthermore, the deep Q-network of DynLight can learn well on determining the
phase duration and DynLight-C demonstrates high performance for deployment.Comment: 9 pages, 9 figure
A Review of Sequential Decision Making via Simulation
Optimization via simulation has been well established to find optimal
solutions and designs in complex systems. However, it still faces modeling and
computational challenges when extended to the multi-stage setting. This survey
reviews the models and methodologies of single-stage optimization via
simulation and multi-stage stochastic programming. These are necessary
theoretical components to push forward the development of sequential decision
making via simulation. We identify the key challenge of sequential decision
making via simulation as the appropriate modeling of the stage-wise value
function, for which we survey the state-of-the-art meta-models and their
potential solution algorithms
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