31,493 research outputs found
Three-generation neutrino oscillations in curved spacetime
Three-generation MSW effect in curved spacetime is studied and a brief
discussion on the gravitational correction to the neutrino self-energy is
given. The modified mixing parameters and corresponding conversion
probabilities of neutrinos after traveling through celestial objects of
constant densities are obtained. The method to distinguish between the normal
hierarchy and inverted hierarchy is discussed in this framework. Due to the
gravitational redshift of energy, in some extreme situations, the resonance
energy of neutrinos might be shifted noticeably and the gravitational effect on
the self-energy of neutrino becomes significant at the vicinities of spacetime
singularities.Comment: 25 pages, 5 figures, 2 tables. Some changes are made according to
referee's suggestions. The final version is to be published at Nuclear
Physics
Distributed Collaborative Monitoring in Software Defined Networks
We propose a Distributed and Collaborative Monitoring system, DCM, with the
following properties. First, DCM allow switches to collaboratively achieve flow
monitoring tasks and balance measurement load. Second, DCM is able to perform
per-flow monitoring, by which different groups of flows are monitored using
different actions. Third, DCM is a memory-efficient solution for switch data
plane and guarantees system scalability. DCM uses a novel two-stage Bloom
filters to represent monitoring rules using small memory space. It utilizes the
centralized SDN control to install, update, and reconstruct the two-stage Bloom
filters in the switch data plane. We study how DCM performs two representative
monitoring tasks, namely flow size counting and packet sampling, and evaluate
its performance. Experiments using real data center and ISP traffic data on
real network topologies show that DCM achieves highest measurement accuracy
among existing solutions given the same memory budget of switches
Distinguish Coding And Noncoding Sequences In A Complete Genome Using Fourier Transform
A Fourier transform method is proposed to distinguish coding and non-coding sequences in a complete genome based on a number sequence representation of the DNA sequence proposed in our previous paper (Zhou et al., J. Theor. Biol. 2005) and the imperfect periodicity of 3 in protein coding sequences. The three parameters P_x(S) (1), P_x(S) (1/3) and P_x(S) (1/36) in the Fourier transform of the number sequence representation of DNA sequences are selected to form a three-dimensional parameter space. Each DNA sequence is then represented by a point in this space. The points corresponding to coding and non-coding sequences in the complete genome of prokaryotes are seen to be divided into different regions. If the point (P_x(�ar S) (1), Px(�ar S) (1/3), P_x(�ar S) (1/36)) for a DNA sequence is situated in the region corresponding to coding sequences, the sequence is distinguished as a coding sequence; otherwise, the sequence is classified as a noncoding one. Fisher's discriminant algorithm is used to study the discriminant accuracy. The average discriminant accuracies pc, pnc, qc and qnc of all 51 prokaryotes obtained by the present method reach 81.02%, 92.27%, 80.77% and 92.24% respectively
Calculation of the Branching Ratio of in PQCD
The branching ratio of is re-evaluated in the PQCD approach.
In this theoretical framework all the phenomenological parameters in the
wavefunctions and Sudakov factor are priori fixed by fitting other experimental
data, and in the whole numerical computations we do not introduce any new
parameter. Our results are consistent with the upper bounds set by the Babar
and Belle measurements.Comment: 12 pages, 1 figure, version to appear in Phys. Rev.
A Mutual Information Based Sequence Distance For Vertebrate Phylogeny Using Complete Mitochondrial Genomes
Traditional sequence distances require alignment. A new mutual information based sequence distance without alignment is defined in this paper. This distance is based on compositional vectors of DNA sequences or protein sequences from complete genomes. First we establish the mathematical foundation of this distance. Then this distance is applied to analyze the phylogenetic relationship of 64 vertebrates using complete mitochondrial genomes. The phylogenetic tree shows that the mitochondrial genomes are separated into three major groups. One group corresponds to mammals; one group corresponds to fish; and the last one is Archosauria (including birds and reptiles). The structure of the tree based on our new distance is roughly in agreement in topology with the current known phylogenies of vertebrates
Type-Aware Decomposed Framework for Few-Shot Named Entity Recognition
Despite the recent success achieved by several two-stage prototypical
networks in few-shot named entity recognition (NER) task, the overdetected
false spans at the span detection stage and the inaccurate and unstable
prototypes at the type classification stage remain to be challenging problems.
In this paper, we propose a novel Type-Aware Decomposed framework, namely
TadNER, to solve these problems. We first present a type-aware span filtering
strategy to filter out false spans by removing those semantically far away from
type names. We then present a type-aware contrastive learning strategy to
construct more accurate and stable prototypes by jointly exploiting support
samples and type names as references. Extensive experiments on various
benchmarks prove that our proposed TadNER framework yields a new
state-of-the-art performance. Our code and data will be available at
https://github.com/NLPWM-WHU/TadNER.Comment: Accepted to the Findings of EMNLP 2023, camera ready versio
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