5,395 research outputs found
Interacting heavy fermions in a disordered optical lattice
We have theoretically studied the effect of disorder on ultracold
alkaline-earth atoms governed by the Kondo lattice model in an optical lattice
via simplified double-well model and hybridization mean-field theory.
Disorder-induced narrowing and even complete closure of hybridization gap have
been predicted and the compressibility of the system has also been investigated
for metallic and Kondo insulator phases in the presence of the disordered
potential. To make connection to the experimental situation, we have
numerically solved the disordered Kondo lattice model with an external harmonic
trap and shown both the melting of Kondo insulator plateau and an
compressibility anomaly at low-density
Cyclotron Dynamics of a Kondo Singlet in a Spin-Orbit-Coupled Alkaline-Earth Atomic Gas
We propose a scheme to investigate the interplay between Kondo-exchange
interaction and quantum spin Hall effect with ultracold fermionic
alkaline-earth atoms trapped in two-dimensional optical lattices using
ultracold collision and laser-assisted tunneling. In the strong Kondo-coupling
regime, though the loop trajectory of the mobile atom disappears, collective
dynamics of an atom pair in two clock states can exhibit an unexpected
spin-dependent cyclotron orbit in a plaquette, realizing the quantum spin Hall
effect of the Kondo singlet. We demonstrate that the collective cyclotron
dynamics of the spin-zero Kondo singlet is governed by an effective
Harper-Hofstadter model in addition to second-order diagonal tunneling
Twinkle: A fast resource provisioning mechanism for internet services
A key benefit of Amazon EC2-style cloud computing service is the ability to instantiate a large number of virtual machines (VMs) on the fly during flash crowd events. Most existing research focuses on the policy decision such as when and where to start a VM for an application. In this paper, we study a different problem: how can the VMs and the applications inside be brought up as quickly as possible? This problem has not been solved satisfactorily in existing cloud services. We develop a fast start technique for cloud applications by restoring previously created VM snapshots of fully initialized application. We propose a set of optimizations, including working set estimation, demand prediction, and free page avoidance, that allow an application to start running with only partially loaded memory, yet without noticeable performance penalty during its subsequent execution. We implement our system, called Twinkle, in the Xen hypervisor and employ the two-dimensional page walks supported by the latest virtualization technology. We use the RUBiS and TPC-W benchmarks to evaluate its performance under flash crowd and failure over scenarios. The results indicate that Twinkle can provision VMs and restore the QoS significantly faster than the current approaches.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000297374700146&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Computer Science, Hardware & ArchitectureComputer Science, Theory & MethodsEngineering, Electrical & ElectronicTelecommunicationsEICPCI-S(ISTP)1
Opinion dynamics on directed small-world networks
In this paper, we investigate the self-affirmation effect on formation of
public opinion in a directed small-world social network. The system presents a
non-equilibrium phase transition from a consensus state to a disordered state
with coexistence of opinions. The dynamical behaviors are very sensitive to the
density of long-range interactions and the strength of self-affirmation. When
the long-range interactions are sparse and individual generally does not insist
on his/her opinion, the system will display a continuous phase transition, in
the opposite case with high self-affirmation strength and dense long-range
interactions, the system does not display a phase transition. Between those two
extreme cases, the system undergoes a discontinuous phase transition.Comment: 6 pages, 5 figure
Study on Administrative and Educational Measures of China Urban Public Fire Safety Education
AbstractTo provide basis of scientific research for administrative and educational measures of China urban public fire safety education in and to ensure its effective implementation, the present situation and problems of China urban public fire safety education are investigated. Based on the research on forming process of public fire safety quality, the requirements of public fire safety education and the efficient education measures are studied. The present management and implement system and its problems of China urban public fire safety education are analyzed, based on a developed information system of public fire safety education and management, a suggested administrative system, enforcement mechanism and implement scheme of public fire safety education measures are proposed in this paper to provide guidance in reforming administrative and educational measures of China urban public fire safety education so as to change the situation of “activities of fire safety education years after years resulting in no improvement of fire safety quality of the public” and make true contribution to improving public fire safety quality in China
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