Speech reconstruction using a deep partially supervised neural network

Statistical speech reconstruction for larynx-related dysphonia has achieved good performance using Gaussian mixture models and, more recently, restricted Boltzmann machine arrays, however deep neural network-based systems have been hampered by the limited amount of training data available from individual voice-loss patients. We propose a novel deep neural network structure that allows a partially supervised training approach on spectral features from smaller datasets, yielding very good results compared to the current state-of-the-art

High prevalence of a globally disseminated hypervirulent clone, Staphylococcus aureus CC121, with reduced vancomycin susceptibility in community settings in China

Objectives: Most vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) are derived from hospital-associated MRSA due to treatment failure; however, the prevalence of hVISA/VISA in community settings remains unclear. Methods: Four hundred and seventy-six community-associated isolates were collected between 2010 and 2011 during national surveillance for antimicrobial resistance in 31 county hospitals across China. Drug susceptibility evaluation and mecA detection were performed by using broth microdilution and PCR analysis, respectively. hVISA/VISA were identified by using macro-Etest and a modified population analysis profile (PAP)-AUC method. The genetic features of all hVISA/VISA isolates were genotyped. Results: Among 476 isolates, MRSA and MSSA accounted for 19.7% (n = 94) and 80.3% (n = 382), respectively. Two VISA and 36 hVISA isolates were identified by PAP-AUC testing. The VISA isolates and 29 of the hVISA isolates were MRSA. The proportion of hVISA/VISA was significantly higher in MRSA (30.9%) than in MSSA (1.8%). The hVISA/VISA isolates were assigned to 18 STs classified into seven clonal complexes (CCs). CC121 (n = 12) followed by ST239 (n = 11) was the most prevalent hVISA/VISA clone. All ST239-hVISA/VISA were MRSA, while 12 CC121-hVISA isolates included 6 MSSA and 6 MRSA isolates. SCCmec III was predominant among MRSA-hVISA/VISA isolates. agr I and agr IV were detected in ST239 and CC121, respectively. All except two strains were positive for Panton-Valentine leucocidin genes. Conclusions: To the best of our knowledge, this is the first report of CC121 as a prevalent hVISA clone in community settings, highlighting the necessity of surveillance and stricter infection control measures for this globally disseminated lineage

Reconstruction of Phonated Speech from Whispers Using Formant-Derived Plausible Pitch Modulation

Whispering is a natural, unphonated, secondary aspect of speech communications for most people. However, it is the primary mechanism of communications for some speakers who have impaired voice production mechanisms, such as partial laryngectomees, as well as for those prescribed voice rest, which often follows surgery or damage to the larynx. Unlike most people, who choose when to whisper and when not to, these speakers may have little choice but to rely on whispers for much of their daily vocal interaction. Even though most speakers will whisper at times, and some speakers can only whisper, the majority of today’s computational speech technology systems assume or require phonated speech. This article considers conversion of whispers into natural-sounding phonated speech as a noninvasive prosthetic aid for people with voice impairments who can only whisper. As a by-product, the technique is also useful for unimpaired speakers who choose to whisper. Speech reconstruction systems can be classified into those requiring training and those that do not. Among the latter, a recent parametric reconstruction framework is explored and then enhanced through a refined estimation of plausible pitch from weighted formant differences. The improved reconstruction framework, with proposed formant-derived artificial pitch modulation, is validated through subjective and objective comparison tests alongside state-of-the-art alternatives

Optimal input potential functions in the interacting particle system method

The assessment of the probability of a rare event with a naive Monte-Carlo method is computationally intensive, so faster estimation methods, such as variance reduction methods, are needed. We focus on one of these methods which is the interacting particle (IPS) system method. The method requires to specify a set of potential functions. The choice of these functions is crucial, because it determines the magnitude of the variance reduction. So far, little information was available on how to choose the potential functions. To remedy this, we provide the expression of the optimal potential functions minimizing the asymptotic variance of the estimator of the IPS method

Reconstruction of Continuous Voiced Speech from Whispers

Whispers are an important secondary vocal communications mechanism, that can be necessary for communicating private information and which are an integral aspect of natural human- to-human dialogue. Furthermore, they may be the primary com- munications method of those suffering from certain forms of aphonia, such as laryngectomees. This paper considers the con- version of continuous whispers to natural-sounding speech, and proposes a new reconstruction method based upon the synthesis of individual formants as excitation source, followed by artifi- cial glottal modulation. Early results show that the proposed method can improve quality and intelligibility over the original whispers when evaluated using continuous speech. It requires neither apriori nor speaker-dependent information, is of rela- tively low-complexity and suitable for real-time processing

Reconstruction of pitch for whisper-to-speech conversion of Chinese

Whispers are a common and necessary secondary vocal communications mechanism for natural human-to-human dialogue. They are also the primary communications mechanism for many suffering from aphonia, such as laryngectomees. For typical speakers, whispering is a predominantly contextual activity, prompted by either the sensitive nature of information being conveyed or in response to environmental considerations. Given the importance of whispers, especially for tonal languages like Chinese, and the fact that many communications systems assume vocalised speech, much work has been directed towards the conversion of whispers into natural sounding speech. Since pitch information is largely absent in whispers, it is this key f0 information which needs to be supplied during the regeneration process, and which is the focus of much research. GMM-based reconstruction techniques have proven effective at whisper reconstruction, and some recent work has proposed the use of artificial pitch derived from formant harmonics as an alternative. This paper describes a new formulation of the formant-harmonic f0 method, and compares this directly against a novel GMM-based f0 estimator, as well as known correct pitch excitation for parallel utterances

Characteristics and Time-Space Evolution of Mining Stress in High Stope

Due to the lack of relevant investigation research on the evolution of mining stress in high stope of metal mines, the understanding of how to ensure the safety during mining process is not clear at all. In this paper, by monitoring the mining-induced pressure of the surrounding rock in the 16-2# stope of Lilou Iron Mine, the evolution of the mining-induced pressure of the subsequent filling and mining method of the high-stage empty field is obtained. The study shows that there are three stages of pressure change in the second-step stope of Lilou Iron Mine: I (stress rising stage), II (stable stage), and III (pressure relief stage), and the mining stress in the surrounding rock is transferred from the top to bottom. The stress transfer model of stope is proposed, and the variation of vertical stress versus the depth is fitted; the four horizontal sections are fitted, respectively. By establishing the three-dimensional numerical model and distributed excavation simulation, the time-space evolution of mining stress is obtained and compared with the in-site measuring result. The two results show high consistency, and the effectiveness of numerical simulation is verified

Drift-off warning limits for deepwater drilling platform/riser coupling system

The drift-off dynamic model of deepwater drilling platform and riser coupling system was established. An analysis method on drift-off warning limits of deepwater drilling platform and riser coupling system was proposed, and a deepwater drilling platform/riser system was taken for case study. The analysis model of deepwater riser, wellhead and conductor coupling system and the drift-off dynamic model of platform were established respectively. The drift-off dynamic solver of deepwater platform was developed. The coupling dynamic characteristics and coupling effect of the deepwater drilling platform and riser system were analyzed in combination with example, and the analysis method for drift-off warning limits was described. The results show that: the riser load acting on platform plays a driving role in the platform drift-off in the initial drift-off stage, and begins to inhibit the platform drift-off gradually as the drift-off displacement increases; During the platform drift-off, the transient response speed of upper riser parameters is high, while the transient response of lower riser parameters presents an obvious hysteresis effect; As the current speed increases or water depth decreases, the drift-off warning limits of deepwater drilling platform/riser coupling system decrease and the deepwater drilling riser should be disconnected earlier. Key words: deepwater drilling, drilling platform, riser, drift-off dynamic model, drift-off warning limit