Recognize Tone Languages Using Pitch Information

An innovative method for speech recognition of tone languages is reported. By definition, the tone of a syllable is determined by the pitch contour of the entire syllable. We propose that the pitch information on the main vowel of a syllable is sufficient to determine the tone of that syllable. Therefore, to recognize tone languages, only main vowels are needed to associate with tones. The number of basic phonetic units required to recognize tone languages is greatly reduced. We then report experimental results on Cantonese and Mandarin. In both cases, using the main vowel method, while the number of phonemes and the quantity of training data are substantially reduced, the decoding accuracy is improved over other methods. Possible applications of the new method to other tone languages, including Thai, Vietnamese, Japanese, Swedish, and Norwegian are discussed

Nanoplate-Built ZnO Hollow Microspheres Decorated with Gold Nanoparticles and Their Enhanced Photocatalytic and Gas-Sensing Properties

Hierarchical porous ZnO microspheres decorated with gold nanoparticles (AuNPs) were successfully synthesized by a facile solvothermal route. The hierarchical ZnO superstructure was constructed of interconnected nanoplates with numerous voids. Photoluminescence, X-ray photoelectron spectroscopy, and electron paramagnetic resonance measurements demonstrated that the main defects were oxygen vacancies (<i>V</i>_O^•) with minor interstitial oxygen (O_i^–) in the hierarchical ZnO hollow microspheres. The as-prepared hierarchical ZnO hollow microspheres and the AuNPs used to decorate them were examined for their photocatalytic degradation ability and as gas sensors. The photodegradation results demonstrated that the degradation rate constant on rhodamine B for undecorated ZnO microspheres was 0.43 min^–1, which increased to 1.76 min^–1 for AuNP-decorated ZnO microspheres. The AuNP-functionalized ZnO microspheres displayed superior sensing properties, with a 3-fold enhancement in their gas response to 1 ppb of dibutyl phthalate