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Traditional noise reduction methods usually are based on the assumption that the short-term statistical distributions of speech and noise are different. Differently from that assumption, we have proposed a noise reduction method based on the assumption that the temporal modulations of noise and speech are different. Two steps are used in the proposed algorithm: one is the temporal modulation contrast...
In this paper, we propose a two-step processing algorithm which adaptively normalizes the temporal modulation of speech to extract robust speech feature for automatic speech recognition systems. The first step processing is to normalize the temporal modulation contrast (TMC) of the cepstral time series for both clean and noisy speech. The second step processing is to smooth the normalized temporal...
Chinese is a tonal language. It has both lexical tones and intonation. The fundamental frequency (F0) contours thereby consist of tone and intonation components. This paper presents an approach to modeling the two components in separate ways and combining them to form the final F0 contours based on a functional F0 model. We analyze tonal patterns as sparse target points (tonal F0 peaks and valleys)...
In this paper, we proposed a robust speech feature extraction algorithm for automatic speech recognition which reduced the noise effect in the temporal modulation domain. The proposed algorithm has two steps to deal with the time series of cepstral coefficients. The first step adopted a modulation contrast normalization to normalize the temporal modulation contrast of both clean and noisy speech to...
Modulation of speaking tone in frequency can make speech interesting and convey subtle meaning in communication. We present a frequency modulation (FM) technique for prosodic modification to consider communicative speech synthesis. This technique provides a mathematical formulation for representing speaking tone and manipulating FM in a unified framework. Two experiments are conducted with a text-to-speech...
For polarization-independent and low-crosstalk switching operation a Mach-Zehnder interferometer (MZI) type photonic switch using Multi-mode interference (MMI) couplers, an optimal structure was investigated. As a result, the combination of high-mesa and middle-mesa waveguides was found to realize low-crosstalk of -30 dB and polarization-independent semiconductor high-speed photonic switch.
We proposed a novel multiport photonic switch in which an input light can be divided into any arbitrary outputs of a multimode interference (MMI) 4times4 coupler, by introducing central modulation regions in MMI waveguide.
We fabricated an InAlGaAs/InAlAs /InP semiconductor photonic switch with a Mach-Zehnder interferometer (MZI) and multi-mode interference (MMI) couplers for low-power consumption operation. As a result, low-current and high-seed switching operation was attained with as low as 3.5 mA and nano-second order experimentally.
Todaypsilas access network is migrating towards broadband IP, fixed/mobile convergence and service convergence. Thus, the next generation access network (NGAN) requires a converged optical/wireless access network infrastructure, other than the existing architecture that connect to the cellular, broadband wireless, and optical access networks separately, which complicate the network and increase the...
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