Browsing by Author "Rao, P."

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    Dravidian language classification from speech signal using spectral and prosodic features
    (2017) Koolagudi, S.G.; Bharadwaj, A.; Srinivasa, Murthy, Y.V.; Reddy, N.; Rao, P.
    The interesting aspect of the Dravidian languages is a commonality through a shared script, similar vocabulary, and their common root language. In this work, an attempt has been made to classify the four complex Dravidian languages using cepstral coefficients and prosodic features. The speech of Dravidian languages has been recorded in various environments and considered as a database. It is demonstrated that while cepstral coefficients can indeed identify the language correctly with a fair degree of accuracy, prosodic features are added to the cepstral coefficients to improve language identification performance. Legendre polynomial fitting and the principle component analysis (PCA) are applied on feature vectors to reduce dimensionality which further resolves the issue of time complexity. In the experiments conducted, it is found that using both cepstral coefficients and prosodic features, a language identification rate of around 87% is obtained, which is about 18% above the baseline system using Mel-frequency cepstral coefficients (MFCCs). It is observed from the results that the temporal variations and prosody are the important factors needed to be considered for the tasks of language identification. 2017, Springer Science+Business Media, LLC.
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    Dravidian language classification from speech signal using spectral and prosodic features
    (Springer New York LLC barbara.b.bertram@gsk.com, 2017) Koolagudi, S.G.; Bharadwaj, A.; Vishnu Srinivasa Murthy, Y.V.; Reddy, N.; Rao, P.
    The interesting aspect of the Dravidian languages is a commonality through a shared script, similar vocabulary, and their common root language. In this work, an attempt has been made to classify the four complex Dravidian languages using cepstral coefficients and prosodic features. The speech of Dravidian languages has been recorded in various environments and considered as a database. It is demonstrated that while cepstral coefficients can indeed identify the language correctly with a fair degree of accuracy, prosodic features are added to the cepstral coefficients to improve language identification performance. Legendre polynomial fitting and the principle component analysis (PCA) are applied on feature vectors to reduce dimensionality which further resolves the issue of time complexity. In the experiments conducted, it is found that using both cepstral coefficients and prosodic features, a language identification rate of around 87% is obtained, which is about 18% above the baseline system using Mel-frequency cepstral coefficients (MFCCs). It is observed from the results that the temporal variations and prosody are the important factors needed to be considered for the tasks of language identification. © 2017, Springer Science+Business Media, LLC.
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    Interfacial bonding of plasma-coated hydroxyapatite on titanium and Ti-6AI-4V
    (2018) Kotian, R.; Rao, P.; Madhyastha, P.
    Aim: The study aimed to understand the interfacial bonding and diffusion of elements between substrate metal and HA-coated titanium implants in different plasma gas atmosphere. Materials and methods: Commercially pure titanium and Ti-6Al-4V substrate metals were coated with hydroxyapatite by plasma spray in plasma gas atmospheres of argon, argon/ hydrogen, nitrogen, and nitrogen/hydrogen. The microstructure and interfacial bonding between the metal substrate and HA coating were studied by scanning electron microscopy, energy dispensive X-ray analysis (EDAX), and X-ray diffraction. Results: The analyses of the coatings obtained showed a different microstructural pattern of HA and diffusion of elements across the interface of metal and HA coating and chemical bonding for all plasma gas atmospheres. Conclusion: The plasma-coating atmosphere influences the microstructure and crystallization of HA. Diffusion of elements from metal substrate to HA coating and coating to metal surface indicate chemical bonding between the metal and coating in addition to usual mechanical bonding. Clinical significance: Bonding between the metal substrate and HA coating play a significant role in the stability of the dental implant. In addition to mechanical bonding, the plasma coated implants show some amount of chemical bonding at the interface. 2018, Jaypee Brothers Medical Publishers (P) Ltd. All rights reserved.
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    Interfacial bonding of plasma-coated hydroxyapatite on titanium and Ti-6AI-4V
    (Jaypee Brothers Medical Publishers (P) Ltd 4838/24 Ansari Road, Daryaganj New Delhi 110 002, 2018) Kotian, R.; Rao, P.; Madhyastha, P.
    Aim: The study aimed to understand the interfacial bonding and diffusion of elements between substrate metal and HA-coated titanium implants in different plasma gas atmosphere. Materials and methods: Commercially pure titanium and Ti-6Al-4V substrate metals were coated with hydroxyapatite by plasma spray in plasma gas atmospheres of argon, argon/ hydrogen, nitrogen, and nitrogen/hydrogen. The microstructure and interfacial bonding between the metal substrate and HA coating were studied by scanning electron microscopy, energy dispensive X-ray analysis (EDAX), and X-ray diffraction. Results: The analyses of the coatings obtained showed a different microstructural pattern of HA and diffusion of elements across the interface of metal and HA coating and chemical bonding for all plasma gas atmospheres. Conclusion: The plasma-coating atmosphere influences the microstructure and crystallization of HA. Diffusion of elements from metal substrate to HA coating and coating to metal surface indicate chemical bonding between the metal and coating in addition to usual mechanical bonding. Clinical significance: Bonding between the metal substrate and HA coating play a significant role in the stability of the dental implant. In addition to mechanical bonding, the plasma coated implants show some amount of chemical bonding at the interface. © 2018, Jaypee Brothers Medical Publishers (P) Ltd. All rights reserved.
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    Numerical investigation on wave transmission characteristics of perforated and non-perforated pile breakwater
    (Institute of Physics Publishing helen.craven@iop.org, 2019) Rao, N.; Rao, P.; Nayak, K.; Kishor Pal, S.; Hunasanahally Sathyanarayana, A.; Suvarna, P.; Umesh, U.
    Dock operations, harbouring and many other port activities demand tranquil water condition. This makes breakwater structures more than essential in coastal engineering applications. For zero wave action, rubble mound or vertical wall breakwaters are used, and for small docks and shores, piles can be used as efficient breakwaters. The permeability of pile breakwaters also aides in keeping the shores clean as there is water circulation and keeps the interferences caused due to littoral drift to the minimum. Numerical study on the single row pile breakwater is carried out using an open source computational fluid dynamics (CFD) software REEF3D. Interaction of waves with non-porous pile breakwater is simulated in a three-dimensional numerical wave tank using REEF3D and resulted transmission coefficient is validated using the physical model studies as reported by Subba Rao et al. (1999). Further, the efficiency of porous piles over non-porous piles is studied by simulating wave conditions by varying wave height, wave period, water depth and percentage porosity of the piles. It has been observed from the present study that porous piles are more efficient in wave attenuation compared to non-porous piles. The reason is that perforations increase turbulence during wave interaction which results in a better wave attenuation. © Published under licence by IOP Publishing Ltd.
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    Polymer Quenchants for Industrial Heat Treatment
    (CRC Press, 2016) Prabhu, K.; Nayak, V.; Rao, P.
    Flux During Quenching 732 25.12 Application of Polymeric Quenchants in Heat Treatment of Steels 734 25.13 Application of Polymeric Quenchants in Heat Treatment of Aluminum Alloys 736 25.14 Summary 738 References 739 during the quench process. Generally, a liquid quench medium is commonly used to facilitate/control the heat transfer during quenching. The most commonly used quenchants in industries worldwide is water followed by oils. On immersion quenching in these liquids, the metal experiences three typical stages of quenching: vapor stage, nucleate boiling stage, and the convective cooling stage. However, the severity of cooling and the duration of the stages in both classes are very much different. Water, because of its severe nature of cooling, provides ample, or exceeds, mechanical properties over that which is required. Moreover, in many circumstances, such as cooling of complex objects or high-alloyed steels, it causes undue distortion, residual stresses, and, in the most severe case, crack formation. Oils, by their very viscous nature, deliver lower cooling performance and reduces is the propensity towards distortion and cracking. The low quench severity of oils results in reduced properties. These limitations compelled the quenchant suppliers to develop polymer quench media that offer the benefit of both water and oils. © 2017 by Taylor and Francis Group, LLC.