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The structure of a neutron-rich F-25 nucleus is investigated by a quasifree (p, 2p) knockout reaction at 270A MeV in inverse kinematics. The sum of spectroscopic factors of pi 0d(5/2) orbital is found to be 1.0 +/- 0.3. However, the spectroscopic factor with residual O-24 nucleus being in the ground state is found to be only 0.36 +/- 0.13, while those in the excited state is 0.65 +/- 0.25. The result shows that the O-24 core of F-25 nucleus significantly differs from a free O-24 nucleus, and the core consists of similar to 35% O-24(g.s.). and similar to 65% excited O-24. The result may infer that the addition of the 0d(5/2) proton considerably changes neutron structure in F-25 from that in O-24, which could be a possible mechanism responsible for the oxygen dripline anomaly.

The paper addresses a robust wavelet-based speech enhancement for automatic speech recognition in reverberant and noisy conditions. We propose a novel scheme in improving the speech, late reflection, and noise power estimates from the observed contaminated signal. The improved estimates are used to calculate theWiener gain in filtering the late reflections and additive noise. In the proposed scheme, optimization of the wavelet family and its parameters is conducted using an acoustic model (AM). In the offline mode, the optimal wavelet family is selected separately for the speech, late reflections, and background noise based on the AM likelihood. Then, the parameters of the selected wavelet family are optimized specifically for each signal subspace. As a result we can use a wavelet sensitive to the speech, late reflection, and the additive noise, which can independently and accurately estimate these signals directly from an observed contaminated signal. For speech recognition, the most suitable wavelet is identified from the pre-stored wavelets, and wavelet-domain filtering is conducted to the noisy and reverberant speech signal. Experimental evaluations using real reverberant data demonstrate the effectiveness and robustness of the proposed method.