arXiv subjects

Haibo Li

Publications and source records attributed to Haibo Li.

45 records · Page 3Linked to original sources

arXiv2015

Leveraging the Power of Gabor Phase for Face Identification: A Block Matching Approach

Different from face verification, face identification is much more demanding. To reach comparable performance, an identifier needs to be roughly N times better than a verifier. To expect a breakthrough in face identification, we need a fresh look at the fundamental building blocks of face recognition. In this paper we focus on the selection of a suitable signal representation and better matching strategy for face identification. We demonstrate how Gabor phase could be leveraged to improve the performance of face identification by using the Block Matching method. Compared to the existing approaches, the proposed method features much lower algorithmic complexity: face images are only filtered by a single-scale Gabor filter pair and the matching is performed between any pairs of face images at hand without involving any training process. Benchmark evaluations show that the proposed approach is totally comparable to and even better than state-of-the-art algorithms, which are typically based on more features extracted from a large set of Gabor faces and/or rely on heavy training processes.

cs.CV↗

arXiv2014

Stability of Numerical Methods for Jump Diffusions and Markovian Switching Jump Diffusions

This work focuses on stability analysis of numerical solutions to jump diffusions and jump diffusions with Markovian switching. Due to the use of Poisson processes, using asymptotic expansions as in the usual approach of treating diffusion processes does not work. Different from the existing treatments of Euler-Maurayama methods for solutions of stochastic differential equations, we use techniques from stochastic approximation. We analyze the almost sure exponential stability and exponential $p$-stability. The benchmark test model in numerical solutions, namely, one-dimensional linear scalar jump diffusion is examined first and easily verifiable conditions are presented. Then Markovian regime-switching jump diffusions are dealt with. Moreover, analysis on stability of numerical methods for linearizable and multi-dimensional jump diffusions is carried out.

math.OC↗

arXiv2013

Study on the properties of the coupling constants of $J/ψ\rightarrow VP$ decays

Basing on the branching fractions of J/ψ\to VP from different experiments, we investigate on the properties of the coupling constants of J/ψ\to VP decays with a model-dependent approach. We find that the octet coupling constant, g_8, of strong interaction is about twice larger than that of the singlet coupling constant g_1; the electromagnetic breaking parameters g^i_E are larger than the mass breaking parameters g^i_M, moreover, the three parameters of electromagnetic effect are about equal, but the three parameters of mass effect are obviously different and their uncertainties are also large; and the phase angle between strong and electromagnetic interaction is in the range of 70^{\circ} \sim 80^{\circ}. It deepens our understanding of the coupling constant of J/ψ\to VP decays.

hep-ph↗

arXiv2011

Strong Predictor-Corrector Euler-Maruyama Methods for Stochastic Differential Equations with Markovian Switching

In this paper numerical methods for solving stochastic differential equations with Markovian switching (SDEwMSs) are developed by pathwise approximation. The proposed family of strong predictor-corrector Euler-Maruyama methods is designed to overcome the propagation of errors during the simulation of an approximate path. This paper not only shows the strong convergence of the numerical solution to the exact solution but also reveals the order of the error under some conditions on the coefficient functions. A natural analogue of $p$-stability criterion is studied. Numerical examples are given to illustrate the computational efficiency of the new predictor-corrector Euler-Maruyama approximation.

math.NA↗

arXiv2006

Study of Scalar Mesons at BES-II

Recent results from BES-II experiment on hadron spectroscopy using $\jpsi$ and $ψ^\prime$ data samples collected in $e^+e^-$ annihilation are presented, including study of the scalar particles in $\jpsi$ radiative and hadronic decays, the observation of X(1810) in $J/ψ\to γϕω$, as well as pair productions of scalars in $χ_{c0}$ hadronic decays.

hep-ex↗

arXiv2006

Clean Prediction of \CP violating processes $ψ$, $ϕ$ and $Υ(1S)$ decay to KsKs and KLKL

The ratio of $K_S K_S$ ($K_L K_L$) and $K_S K_L$ production rates is calculated by considering $K^0 - K^0bar$ oscillation in $J/ψ\to K^0K^0bar$ decay. The theoretical uncertainty due to strong interaction in $J/ψ$ decay is completely canceled in the ratio, therefore, the absolute branching fractions of the \CP violating processes of $J/ψ\to K_S K_S $ and $K_L K_L$ can be cleanly and model-independently determined in case that $J/ψ\to K_S K_L$ decay is precisely measured. In the future $τ$-Charm factory, the expected \CP violating process of $J/ψ\to K_S K_S $ should be reached. It is important to measure $J/ψ$ to $K_S K_S$ and K_S K_L decays simultaneously, so that many systematic errors will be canceled. More precise measurements are suggested to examine the predicted isospin relation in $J/ψ\to KKbar$ decays. All results can be extended to decays of other vector quarkonia, $ϕ$, $ψ(2S)$ and $Υ(1S)$ and so on.

hep-ph↗

arXiv2006

Proposal of Direct Search for Strongly Bound States of ppbar, npbar Systems with High Intensity and Collective pbar beam

In this letter, we discuss the possibility to look for the direct evidence of the existence of the ppbar and npbar bound states. Measurement of the single γray from the ppbar and npbar systems at rest can directly confirm whether the X(1860) and X(1835) are the resonances which are strongly coupled to ppbar. In addition to the neutral candidate, a charged resonance $X^-$ is also proposed to be searched for in npbar channel. We find that the data from the Crystal Barrel experiment at LEAR/CERN can be used to confirm the X(1835) observed by BES Collaboration. The possibility of measuring the $γ$ spectrum below 100 MeV at the new experiment with cold high intensity $\pbar$ beam at GSI is discussed. These new techniques can be used to probe the structure of the X(1860) and X(1835) in the future.

hep-ex↗

arXiv2006

Charm Physics with BES-III at BEPC-II

We report on the charm physics potential at BES-III at BEPC-II which will make significant contribution to quark flavor physics this decade. The charm physics program will include studies of leptonic, semileptonic and hadronic charm decays, and tests for physics beyond the Standard Model. Event samples of the order of 30 million $\DD$ pairs, 2 million $\DspDsm$ pairs at threshold and $10\times 10^9$ $J/ψ$ decays will be produced with one year design luminosity. High precision charm data will enable us to validate forthcoming Lattice QCD calculations at the few percent level. These can then be used to make precise measurements of CKM elements, $V_{cd}$, $V_{cs}$, $V_{ub}$, $V_{cb}$ and $V_{ts}$, which are useful to improve the accuracy of test of the CKM unitarity.

hep-ex↗

arXiv2004

Constraints on the CKM angle alpha in the B --> rho rho decays

Using a data sample of 122 million Upsilon(4S) -> BBbar decays collected with BaBar detector at the PEP-II asymmetric B factory at SLAC, we measure the time-dependent-asymmetry parameters of the longitudinally polarized component in the B0 -> rho^+ rho^- decay as C_L = -0.23 +/- 0.24 (stat) +/- 0.14 (syst) and S_L = -0.19 +/- 0.33 (stat) +/- 0.11 (syst). The B0 -> rho0 rho0 decay mode is also searched for in a data sample of about 227 million BBbar pairs. No significant signal is observed, and an upper limit of 1.1 * 10-6 (90% C.L.) on the branching fraction is set. The penguin contribution to the CKM angle $α$ uncertainty is measured to be 11 degree. All results are preliminary.

hep-ex↗