1,073 research outputs found

    Rhythm-Flexible Voice Conversion without Parallel Data Using Cycle-GAN over Phoneme Posteriorgram Sequences

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    Speaking rate refers to the average number of phonemes within some unit time, while the rhythmic patterns refer to duration distributions for realizations of different phonemes within different phonetic structures. Both are key components of prosody in speech, which is different for different speakers. Models like cycle-consistent adversarial network (Cycle-GAN) and variational auto-encoder (VAE) have been successfully applied to voice conversion tasks without parallel data. However, due to the neural network architectures and feature vectors chosen for these approaches, the length of the predicted utterance has to be fixed to that of the input utterance, which limits the flexibility in mimicking the speaking rates and rhythmic patterns for the target speaker. On the other hand, sequence-to-sequence learning model was used to remove the above length constraint, but parallel training data are needed. In this paper, we propose an approach utilizing sequence-to-sequence model trained with unsupervised Cycle-GAN to perform the transformation between the phoneme posteriorgram sequences for different speakers. In this way, the length constraint mentioned above is removed to offer rhythm-flexible voice conversion without requiring parallel data. Preliminary evaluation on two datasets showed very encouraging results.Comment: 8 pages, 6 figures, Submitted to SLT 201

    A unique seasonal pattern in dissolved elemental mercury in the South China Sea, a tropical and monsoon-dominated marginal sea

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    Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 40 (2013): 167–172, doi:10.1029/2012GL054457.A unique seasonal pattern in dissolved elemental mercury (DEM) was observed in the tropical monsoon-dominated South China Sea (SCS). The DEM concentration varied seasonally, with a high in summer of 160 ± 40 fM (net evasion 580 ± 120 pmol m−2 d−1, n = 4) and a low in winter of 60 ± 30 fM (net invasion −180 ± 110, n = 4) and showed a positive correlation with sea surface temperature (SST). The elevated DEM concentration in summer appears mainly abiologically driven. In winter, the SCS acts as a sink of atmosphere Hg0 as a result of low SST and high wind of the year, enhanced vertical mixing, and elevated atmospheric gaseous elemental mercury. Annually, the SCS serves as a source of Hg0 to the atmosphere of 300 ± 50 pmol m−2 d−1 (385 ± 64 kmol Hg yr−1, ~2.6% of global emission in ~1% of global ocean area), suggesting high regional Hg pollution impacts from the surrounding Mainland (mostly China).Support was provided by the National Science Council through grants NSC 97-2745-M-002- 001-;98(99,100)-2611-M-002-013(014,004) and from the College of Science, National Taiwan University under the “Drunken Moon Lake Scientific Integrated Scientific Research Platform” grant, NTU 101R3252, as well as through the U.S. National Science Foundation under grant OCE-1132515 and 0928191.2013-07-1

    Interactions Between Reinforcement Corrosion and Chloride Ion Diffusion in Mortar

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    This study explored the diffusion of the chloride ions influenced by the reinforcement corrosion in the mortar. It is believed that, during the corroding process, a small current is generated at the surface of the reinforcement. Such current is supposed to influence the diffusion of the chloride ions, but the relationship between both was not well studied in the literature. In this study, the corroded reinforcements were prepared by applied currents. Reinforced mortar specimens with w/c of 0.6 were then prepared and cured by either salt or fresh water. Results showed that the chloride ion distribution was likely associated with the reinforcement corrosion. During the early hydration, the chloride ions were attracted by the reinforcement corrosion in the specimens prepared with fresh water and cured in salt water. The concentration of the chloride ions near the surface of the reinforcement was increased with the increases of the charging time during the preparation for the corroded reinforcement. On the contrary, the chloride ions were likely bound in those specimens prepared with salt water and cured by saturated lime water. The concentration of the chloride ions near the surface of the reinforcement was higher than those near the outer surface. However, such influencing effects were not clear in the long term, possibly due to the hydration. The results of this study show that the reinforcement corrosion have influences on the diffusion of the chloride ions and such effect should be considered during the refinement of the traditional chloride ion diffusion models

    Therapeutic Applications and Mechanisms of YC-1: A Soluble Guanylate Cyclase Stimulator

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    Nitric oxide (NO) is an essential endogenous vasodilator to maintain vascular homeostasis, whose effects are mainly mediated by NO-dependent soluble guanylate cyclase (sGC) which catalyzes the synthesis of cyclic guanosine monophosphate (cGMP), a critical mediator of vascular relaxation. YC-1, a novel NO-independent sGC stimulator, was first introduced as an inhibitor of platelet aggregation and thrombosis. Accumulating studies revealed that YC-1 has multiple medication potentials to use for a broad spectrum of diseases ranging from cardiovascular diseases to cancers. In contrast to NO donors, YC-1 has a more favorable safety profile and low medication tolerance. In this chapter, we introduce canonical and pathological roles of NO, review activations, and regulatory mechanisms of YC-1 on NO-independent sGC/cGMP pathway and present the potential pharmacological applications and molecular mechanisms of YC-1

    Space Net Optimization

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    Most metaheuristic algorithms rely on a few searched solutions to guide later searches during the convergence process for a simple reason: the limited computing resource of a computer makes it impossible to retain all the searched solutions. This also reveals that each search of most metaheuristic algorithms is just like a ballpark guess. To help address this issue, we present a novel metaheuristic algorithm called space net optimization (SNO). It is equipped with a new mechanism called space net; thus, making it possible for a metaheuristic algorithm to use most information provided by all searched solutions to depict the landscape of the solution space. With the space net, a metaheuristic algorithm is kind of like having a ``vision'' on the solution space. Simulation results show that SNO outperforms all the other metaheuristic algorithms compared in this study for a set of well-known single objective bound constrained problems in most cases.Comment: 12 pages, 6 figure

    Semantic Frame-based Statistical Approach for Topic Detection

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    Anthropomorphism of AI-based Intelligent Customer Service, and Its Affective and Behavioral Consequences

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    Recently, as many users turn to social media to interact with service providers, organizations apply Artificial intelligence (AI) to improve the efficiency and effectiveness of the operation. This type of customer service system is called intelligent customer service (ICS) which one of the most commonly adopted tools is chatbot. Since chatbot is AI-empowered, whether this system can effectively interact with customers and solve their problems is critical. However, the quality of ICS has received significant attention recently, and a lack of systematic study on the outcomes of anthropomorphism leaves this question unanswered in an ICS context. Based on a cognitive-affective-behavioral framework, this study attempts to understand whether anthropomorphism can promote desired behaviors (including usage and citizen-ship behaviors) through enhancing affective out-comes, such as satisfaction and identity. Data collected from 183 chatbot-ICS users, this study illustrates how anthropomorphism can increase quality, enhance satisfaction and identity. Furthermore, we also show that satisfaction and identity lead to further usage and citizenship behaviors. This highlights the importance of increasing anthropomorphism for the chatbot-ICS

    Fluoroquinolones are associated with delayed treatment and resistance in tuberculosis: a systematic review and meta-analysis

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    SummaryBackgroundCurrent guidelines for treating community-acquired pneumonia recommend the use of fluoroquinolones for high-risk patients. Previous studies have reported controversial results as to whether fluoroquinolones are associated with delayed diagnosis and treatment of pulmonary tuberculosis (TB) and the development of fluoroquinolone-resistant Mycobacterium tuberculosis. We performed a systematic review and meta-analysis to clarify these issues.MethodsThe following databases were searched through September 30, 2010: PubMed, EMBASE, CINAHL, Cochrane Library, Web of Science, BIOSIS Previews, and the ACP Journal Club. We considered studies that addressed the issues of delay in diagnosis and treatment of TB and the development of resistance.ResultsNine eligible studies (four for delays and five for resistance issues) were included in the meta-analysis from the 770 articles originally identified in the database search. The mean duration of delayed diagnosis and treatment of pulmonary TB in the fluoroquinolone prescription group was 19.03 days, significantly longer than that in the non-fluoroquinolone group (95% confidence interval (CI) 10.87 to 27.18, p<0.001). The pooled odds ratio of developing a fluoroquinolone-resistant M. tuberculosis strain was 2.70 (95% CI 1.30 to 5.60, p=0.008). No significant heterogeneity was found among studies in the meta-analysis.ConclusionsEmpirical fluoroquinolone prescriptions for pneumonia are associated with longer delays in diagnosis and treatment of pulmonary TB and a higher risk of developing fluoroquinolone-resistant M. tuberculosis

    UNDERSTANDING COMPETITIVE PERFORMANCE OF SOFTWARE-AS-A-SERVICE (SAAS)—THE COMPETITIVE DYNAMICS PERSPECTIVE

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    Understanding the antecedents and consequences of a firm’s agility in cloud software applications is important. This papers draws on the competitive dynamics perspective to develop a model that explains the relationships between collaboration with vendors, agility, and competitive performance in software-as-a-service (SaaS) context. Collaboration reflects a firm’s ability to leverage interfirm resources, characterized as knowledge sharing and process alignment. Agility is measured by a firm’s strategy-oriented agility and service-oriented agility. This study also investigates the moderating effect of environmental turbulence. The proposed hypotheses are supported by the empirical data. The results show that competitive performance is affected by ability, which, in turn, is impacted by collaboration. Environmental turbulence positively moderates the relationship between agility and performance. Finally, we discuss the implications of our results
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