206 research outputs found

    Salient Object Detection Based on Background Feature Clustering

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    Automatic estimation of salient object without any prior knowledge tends to greatly enhance many computer vision tasks. This paper proposes a novel bottom-up based framework for salient object detection by first modeling background and then separating salient objects from background. We model the background distribution based on feature clustering algorithm, which allows for fully exploiting statistical and structural information of the background. Then a coarse saliency map is generated according to the background distribution. To be more discriminative, the coarse saliency map is enhanced by a two-step refinement which is composed of edge-preserving element-level filtering and upsampling based on geodesic distance. We provide an extensive evaluation and show that our proposed method performs favorably against other outstanding methods on two most commonly used datasets. Most importantly, the proposed approach is demonstrated to be more effective in highlighting the salient object uniformly and robust to background noise

    A novel scheme on multi-channel mechanical fault signal diagnosis based on augmented quaternion singular spectrum analysis

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    In this paper, a novel multi-channel mechanical failure signal classification method based on augmented quaternion singular spectrum analysis (AQSSA) is proposed. Quaternion is used to couple four channels signal, and the quaternion trajectory matrixes can be developed as augmented quaternion matrix by using the feature of the quaternion. The singular value sequence including characteristic information can be extracted by quaternion singular value decomposition (QSVD) of the augmented trajectory matrix using its covariance matrix. The method of traditional singular spectrum analysis (SSA) can only analyze the single channel signal, however, AQSSA can fully use the correlation of multi-channel and reduce the loss of the effective information. Additionally, the main singular values are defined by some methods such as difference spectrum aimed, which has the limitation that major singular values can’t be obtained under the high background noise. Thus, a concept of partial mean of singular value sequence is proposed, and it can be set as the standard of evaluating the trend of singular value sequence. In order to testify the performance of the proposed method, the numerical simulation signal and the fault vibration signal of bearing are simultaneously adopted to verify its effectiveness. The results indicate that the effectiveness of mechanical fault classification by the proposed method is superior to the traditional SSA method and the method of permutation entropy

    Zerumbone decreases BACH1 levels by upregulating miR- 708 to inhibit breast cancer cell proliferation and invasion

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    Purpose: To investigate the potential mechanism by which zerumbone suppresses breast cancer (BC) cells.Methods: Cell viability and Transwell assays were performed to assess the effect of zerumbone on BC cell growth. The downstream target of zerumbone was determined using quantitative polymerase chain reaction assays and immunoblotting. Cell viability assays and immunoblotting were conducted to detect if zerumbone had any effect on BACH1 (BTB domain and CNC homolog 1) expression.Results: Zerumbone suppressed the proliferation, migration, and invasion of BC cells. It also upregulated the expression of microRNA (miR)-708 and, hence, suppressed BACH1 expression. Furthermore, zerumbone suppressed the proliferation and invasion of BC cells by promoting miR-708expression and suppressing BACH1.Conclusion: The findings help clarify the anti-tumor mechanism of zerumbone and provide theoretical and therapeutic bases for the anti-tumor effects of Chinese herbal medicine. Keywords: Breast cancer, Zerumbone, Cell invasion, MiR-708, BACH

    N′-(4-Hydr­oxy-3-methoxy­benzyl­idene)acetohydrazide monohydrate

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    In the title compound, C10H12N2O3·H2O, the Schiff base mol­ecule is approximately planar [within 0.189 (1) Å]. The inter­planar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, mol­ecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydr­oxy H atom deviates from the 4-hydr­oxy-3-methoxy­phenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R 1 2(4) motif. A weak C—H⋯π inter­action is also present

    N′-(3,4-Dihydroxy­benzyl­idene)acetohydrazide

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    In the title compound, C9H10N2O3, the Schiff base mol­ecule is approximately planar, the dihedral angle between the benzene ring and the acetohydrazide group (r.m.s. deviation = 0.034 Å) being 8.81 (7)°. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, mol­ecules are linked into a three-dimensional network by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds

    (E)-Methyl N′-(2-furylmethyl­ene)­hydrazinecarboxyl­ate

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    The title compound, C7H8N2O3, crystallizes with two independent but essentially identical mol­ecules in the asymmetric unit. Each mol­ecule adopts a trans configuration with respect to the C=N bond. The hydrazinecarboxyl­ate group is twisted from the furan ring by 7.78 (13)° in one mol­ecule and by 7.01 (17)° in the other. In the crystal structure, mol­ecules are linked into chains running along [010] by bifurcated N—H⋯(N,O) and N—H⋯O hydrogen bonds. In addition, weak C—H⋯O inter­actions and an O⋯C short contact [2.896 (3) Å] are observed

    Prolonged dual antiplatelet therapy in patients with non-ST-segment elevation myocardial infarction: 2-year findings from EPICOR Asia.

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    BACKGROUND: Patients with non-ST-segment elevation myocardial infarction (NSTEMI) have a generally poor prognosis and antithrombotic management patterns (AMPs) used post-acute coronary syndrome (ACS) remain unclear. Duration of dual antiplatelet therapy (DAPT) and patient characteristics was evaluated in NSTEMI patients enrolled in EPICOR Asia. HYPOTHESIS: Patients stopping DAPT early may benefit from more intensive monitoring. METHODS: EPICOR Asia was a prospective, real-world, primary data collection, cohort study in adults with an ACS, conducted in eight countries/regions in Asia, with 2 year follow-up. Eligible patients were hospitalized within 48 hours of symptom onset and survived to discharge. We describe AMPs and baseline characteristics in NSTEMI patients surviving ≥12 months with DAPT duration ≤12 and > 12 months post-discharge. Clinical outcomes (composite of death, myocardial infarction, and stroke; and bleeding) were also explored. RESULTS: At discharge, 90.8% of patients were on DAPT (including clopidogrel, 99%). At 1- and 2-year follow-up, this was 79.2% and 60.0%. Patients who stopped DAPT ≤12 months post-discharge tended to be older, female, less obese, have prior cardiovascular disease, and have renal dysfunction. While causality cannot be inferred, the incidence of the composite endpoint over the subsequent 12 months was 10.6% and 3.1% with shorter vs longer use of DAPT, and mortality risk over the same period was 8.4% and 1.6%. CONCLUSIONS: Over 90% of NSTEMI patients were discharged on DAPT, with 60% on DAPT at 2 years. Patients stopping DAPT early were more likely to have higher baseline risk and may therefore benefit from more intensive monitoring during long-term follow-up

    (E)-Methyl N′-(2-hydr­oxy-3-methoxy­benzyl­idene)hydrazinecarboxyl­ate

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    The title compound, C10H12N2O4, adopts a trans configuration with respect to the C=N double bond. The non-H atoms of the mol­ecule are essentially coplanar, with a maximum deviation of 0.015 (2) Å. An intra­molecular O—H⋯N inter­action is observed. In the crystal structure, the mol­ecules are linked into a two-dimensional network parallel to the ac plane by N—H⋯O hydrogen bonds involving the meth­oxy O atom and by two C—H⋯O hydrogen bonds involving the carbonyl O atom. In addition, an intermolecular C—H⋯π inter­action is observed

    A simple all-fiber comb filter based on the combined effect of multimode interference and Mach-Zehnder interferometer

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    A polarization-dependent all-fiber comb filter based on a combination effect of multimode interference and Mach-Zehnder interferometer was proposed and demonstrated. The comb filter was composed with a short section of multimode fiber (MMF) fusion spliced with a conventional single mode fiber on the one side and a short section of a different type of optical fiber on the other side. The second type of optical fiber is spliced to the MMF with a properly designed misalignment. Different types and lengths of fibers were used to investigate the influence of fiber types and lengths on the performance of the comb filter. Experimentally, several comb filters with free spectral range (FSR) values ranging from 0.236 to 1.524 nm were achieved. The extinction ratio of the comb filter can be adjusted from 6 to 11.1 dB by varying polarization states of the input light, while maintaining the FSR unchanged. The proposed comb filter has the potential to be used in optical dense wavelength division multiplexing communication systems
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