7,221 research outputs found

    A Speech Recognition System Based Improved Algorithm of Dual-template HMM

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    AbstractThe hidden Markov (HMM) and speech recognition algorithm based this model were studied in the paper. In addition the model and recognition algorithm of HMM got be improved based on the traditional the HMM. In the process of modeling, through the training of multiple observe sequence to achieve the recognition of non-specific people, and according to the different number of HMM states to establish the double-template of rough and high precision, and through the second matching algorithm to achieve higher recognition rate. A speech recognition system combined MFCC parameters and HMM algorithm was constructed based improved HMM algorithm. Experimental result shown the speech recognition rate of large vocabulary of non-specific people was greatly improved

    High-Order Topological Phase Diagram Revealed by Anomalous Nernst Effect in Janus ScClI Monolayer

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    Higher-order topological properties of two-dimensional(2D) magnetic materials have recently been proposed. In 2D ferromagnetic Janus materials, we find that ScClI is a second-order topological insulator (SOTI). By means of a multi-orbital tight-binding model, we analyze the orbital contributions of higher-order topologies. Further, we give the complete high-order topological phase diagram of ScClI, based on the external field modulation of the magneto-valley coupling and energy levels. 2D ScClI has a pronounced valley polarization, which causes different insulating phases to exhibit completely different anomalous Nernst conductance. As a result, we use the matched anomalous Nernst effect to reveal the topological phase transition process of ScClI. We utilize the characteristics of valley electronics to link higher-order topological materials with the anomalous Nernst effect, which has potential implications for high-order topological insulators and valley electronics.Comment: 6 pages, 3 page

    Blood-Oxygenation-Level-Dependent-(BOLD-) Based R2′ MRI Study in Monkey Model of Reversible Middle Cerebral Artery Occlusion

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    Objective. To investigate the value of BOLD-based reversible transverse relaxation rate (R2′) MRI in detecting ischemic penumbra (IP) in a monkey model of reversible middle cerebral artery occlusion (MCAO) and time evolution of relative R2′ (rR2′) in infarcted core, IP, and oligemia. Materials and Methods. 6 monkeys were used to make MCAO by the microcatheter method. MR scans were performed at 0 h (1 h after MCAO), 1 h, 3 h, 6 h, 12 h, 24 h, and 48 h after reperfusion. R2′ was calculated using quantitative T2 and T2* maps. Ischemic area was subdivided into infracted core, IP and oligemia. rR2′ was calculated respectively. Results. Reversible MCAO model for 4/6 monkeys was made successfully. rR2′ values were significantly different at each time point, being highest in oligemia followed by IP and infarcted core (P < .05). With reperfusion time evolution, rR2′ in infarcted core showed a decreased trend: sharply decreased within 6 hours and maintained at 0 during 6–48 hours (P < .05). rR2′ values in IP and oligemia showed similar increased trend: sharply increased within 6 hours, maintained a plateau during 6–24 hours, and slightly increased until 48 hours. Conclusion. BOLD-based R2′ MRI can be used to describe changes of cerebral oxygen extract in acute ischemic stroke, and it can provide additional information in detecting IP. The time evolution rR2′ in infarcted core, IP, and oligemia is in accordance with the underlying pathophysiology
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