Max-margin Metric Learning for Speaker Recognition

Probabilistic linear discriminant analysis (PLDA) is a popular normalization approach for the i-vector model, and has delivered state-of-the-art performance in speaker recognition. A potential problem of the PLDA model, however, is that it essentially assumes Gaussian distributions over speaker vectors, which is not always true in practice. Additionally, the objective function is not directly related to the goal of the task, e.g., discriminating true speakers and imposters. In this paper, we propose a max-margin metric learning approach to solve the problems. It learns a linear transform with a criterion that the margin between target and imposter trials are maximized. Experiments conducted on the SRE08 core test show that compared to PLDA, the new approach can obtain comparable or even better performance, though the scoring is simply a cosine computation

Anomaly of zero-bias conductance peaks in ferromagnet/d-wave superconductor junctions

The Blonder-Tinkham-Klapwijk approach is applied to studying spin-polarized quasiparticle transport in ferromagnet (FM)/d-wave superconductor (SC) junctions by taking into account the roughness of the interfacial barrier, broken time-reversal symmetry (BTRS) states near the surface of the SC, and exchange interactions in the FM. It is shown that (1) the exchange splitting in the FM decreases the height of the zero-bias conductance peak (ZBCP) and may induce a zero-bias conductance dip (ZBCD), (2) the presence of the BTRS states in the SC may make the ZBCP split into two peaks, and (3) the interface roughness obstructs the ZBCP splitting and decreases the height of the ZBCP. The calculated results can account for the ZBCD observed experimentally in La 2/3Ba 1/3MnO 3/DyBa 2Cu 3O 7 and La 2/3Ba 1/3MnO 3/YBa 2Cu 3O 7-δ junctions.published_or_final_versio

On the Gamma-Ray Emission of the Andromeda Galaxy M31

Using the $\gamma$-ray data obtained with the Large Area Telescope (LAT) onboard {\it the Fermi Gamma-ray Space Telescope (Fermi)} for $\sim$14 years, we examine the high energy emission emanating from the center of the Andromeda Galaxy M31. Different from previously reported results, which show a seemingly extended source, we instead find two individual point sources, one consistent with being at the center and one 0\fdg4 south-east of the center. The emission of the former is well described using a Log-Parabola model, similar to those of previous studies, and that of the latter can be fitted with a power law. We discuss the possible origins for the two sources. M31's central source, now consistent with being a point source, necessitates a revisit of its previously discussed originations with this new property taken into consideration, in particular those cosmic rays or dark matter scenarios involving extended source distributions. The SE source appears to have a projected distance of $\sim$6\,kpc from M31's center, and the investigation is required as to whether it is a source locally associated with M31, or is instead a background extra-galactic one.Comment: 6 pages, 2 figures, 2 tables, accepted for publication in ApJ

NLO fragmentation functions for a quark into a spin-singlet quarkonium: Same flavor case

In the paper, we calculate the fragmentation functions for $c \to \eta_c$ and $b \to \eta_b$ up to next-to-leading-order (NLO) QCD accuracy. The ultraviolet divergences in the real corrections are removed through operator renormalization under the modified minimal subtraction scheme. We then obtain the fragmentation functions $D_{c \to \eta_c}(z,\mu_F)$ and $D_{b \to \eta_b}(z,\mu_F)$ up to NLO QCD accuracy, which are presented as figures and fitting functions. The numerical results show that the NLO corrections are significant. The sensitives of the fragmentation functions to the renormalization scale and the factorization scale are analyzed explicitly.Comment: 18 pages, 7 figure

Comparison of capecitabine and tegafur/gimeracil/oteracil (S-1) in the treatment of advanced breast carcinoma in the elderly

Purpose: To analyse and compare the clinical effects and safety of capecitabine and tegafur/gimeracil/oteracil (S-1) in the treatment of advanced breast carcinoma.Methods: Eighty-four metastatic breast cancer elderly patients for whom first or second-line treatment had failed, were selected from among those admitted to the oncology ward of Binjiang People’s Hospital, China between January 2014 and June 2015. They were randomly divided into S-1 group (n =41) and capecitabine group (n = 41) and received varying doses of those drugs  according to body surface area. Clinical effects, progression-free survival, and incidence of adverse reactions were compared for the two groups following treatment.Results: Disease control rate (CR) in S-1 group was 55.6 %, much higher than 35.1 % observed for capecitabine group (p < 0.05). The disease control rate for the S-1 group was 93.7 %, also much higher than the 70.6 % found in capecitabine group. Survival analysis showed that the median survival times of the two groups did not differ significantly (p > 0.05). Furthermore, some adverse reactions such as myelosuppression and lack of strength, did not differ significantly between the two groups (p > 0.05), whereas others, including leukopenia, nausea and vomiting and hand-foot syndrome were more serious and frequent in capecitabine group than in S-1 group (p < 0.05).Conclusion: Monotherapy with S-1 is more effective than that with capecitabine. Adverse reactions are minimal for both drugs.Keywords: Breast carcinoma, Capecitabine, S-1, Adverse reactions,  Myelosuppression, Leukopenia, Hand-foot syndrom

Targeting Integrin-β1 Impedes Cytokine-Induced Osteoclast Differentiation: A Potential Pharmacological Intervention in Pathological Osteolysis

Purpose: To examine whether integrin-β1 is essential for osteoclast differentiation and function and if it can be targeted for pharmacological intervention in pathological osteolysis.Methods: Control and Integrin-β1 knockdown RAW 264.7 cells were treated with receptor activator of nuclear factor kappa-B (RANKL) or TNF-α and evaluated for osteoclast differentiation. Osteoclast differentiation and function were evaluated by marker protein analysis, tartrate-resistant acid phosphatase (TRAP) and resorption assays. Furthermore, downstream molecular signaling analysis was probed using small molecule inhibitors and blocking antibodies, and evaluated by immunoblotting.Results: Integrin-β1 knockdown cells showed reduced osteoclast differentiation following TNF-α treatment while no change was seen after RANKL treatment (p < 0.05). Immunoblot-based molecular signaling analysis showed involvement of MAPK kinase signaling in mediating TNF-α/integrin-β1- induced osteoclastogenesis. Finally, when MAPK kinase inhibitor (2.5 and 5 μM; p < 0.05) and integrin- β1 blocking antibody (2.5 and 5 μg/mL; p < 0.05) was used to specifically attenuate TNF-α induced osteoclastogenesis, no change was observed in RANKL-induced osteoclast formation.Conclusion: The data obtained highlight the role of integrin-β1 in TNF-α-induced osteoclastogenesis, but not in RANKL pathway. Given that, inflammatory cytokine secretions such as TNF-α are progressively implicated in pathological osteolysis, targeting this pathway may attenuate osteolysis in pathological bone tissues.Keywords: Osteoclast differentiation, Integrin-β1, Receptor activator of nuclear factor kappa-B, TNFalpha, Mitogen activated protein kinase, Cytokines, Skeletal diseas

Coherent quantum transport in ferromagnet/superconductor/ferromagnet structures

The Blonder-Tinkham-Klapwijk (BTK) approach is extended to study coherent quantum transport in ferromagnet/superconductor/ferromagnet (FM/SC/SM) double tunnel junctions. In order to guarantee current conservation it is necessary to simultaneously consider spin-polarized electron currents along one direction and spin-polarized hole currents along the opposite direction, and to determine self-consistently the chemical potential in SC. It is found that all the reflection and transmission coefficients'in BTK theory as well as conductance spectra oscillate with energy, exhibiting different behavior in the metallic and tunnel limits.published_or_final_versio

Analysis on vibrations and infrared absorption of uncooled microbolometer

The characteristics of vibrations in microbolometer had significant impact on the performances of its infrared absorption. Due to the complex architectures, leading to the unfavorable connection between the analysis of infrared absorption and vibrations. To solve this issue, a finite element analysis (FEA) method was designed to make better compatible with infrared absorption and vibrations, as well as the resonant frequency analysis was completed. A vanadium oxide (VO2) based microbolometer was designed, and the corresponding three-dimensional (3D) modeling was also built. By vibrations and resonant frequency FEA, mechanics and frequency characteristic were studied. 200 G, 500 G and 1000 G acceleration vibrations were loaded on the 3D model at Z axis, which perpendicular to the bridge-like structure. It shows that under 500 G acceleration vibration, the deformation of the model was small enough to ensure the resonant cavity maintained λ/4 which means a high IR absorption for the microbolometer. The first order modal frequency, the second order modal frequency and the third order modal frequency of the 3D model were also analyzed. Purpose of resonant frequency analyzing of microbolometer was to avoid devices work on this frequency result of failure. Finally, an uncooled infrared focal plane was fabricated, and the experimental data matched the simulation fitting results. Perfect performance in mechanical properties, IR absorption and imaging effect of experimental device indicating a shorter design cycle and low cost potential. The fast, efficient FEA design method enables simulating infrared absorption and vibrations together