Effect of Vowel Context on the Recognition of Initial Consonants in Kannada

Mohan Kumar Kalaiah,Jayashree S Bhat 대한청각학회 2017 Journal of Audiology & Otology Vol.21 No.3

Background and Objectives: The present study was carried out to investigate the effect ofvowel context on the recognition of Kannada consonants in quiet for young adults. Subjectsand Methods: A total of 17 young adults with normal hearing in both ears participatedin the study. The stimuli included consonant-vowel syllables, spoken by 12 native speakersof Kannada. Consonant recognition task was carried out as a closed-set (fourteen-alternativeforced-choice). Results: The present study showed an effect of vowel context on theperception of consonants. Maximum consonant recognition score was obtained in the /o/vowel context, followed by the /a/ and /u/ vowel contexts, and then the /e/ context. Poorestconsonant recognition score was obtained in the vowel context /i/. Conclusions: Vowel contexthas an effect on the recognition of Kannada consonants, and the vowel effect wasunique for Kannada consonants.

Effect of ethylenediamine tetra acetic acid additive on the nucleation kinetics and growth aspects of L-arginine phosphate single crystals

Kumar, R.Mohan,Babu, D.Rajan,Ravi, G.,Jayavel, R. The Korea Association of Crystal Growth 2003 韓國結晶成長學會誌 Vol.13 No.4

Pure and Ethylenediaminetetraacetic acid (EDTA) doped L-arginine phosphate (LAP) single crystals were grown from the aqueous solution by temperature lowering method. The effect of EDTA additive on the solubility and metastable zone width of LAP solution has been investigated. Addition of EDTA has enhanced the metastable zone width of LAP and hence bulk crystals could be grown. The growth rate along the [100] direction increases with EDTA additive. Powder X-ray diffraction and FTIR studies reveal the absence of EDTA in the lattice of LAP, This reveals that the addition of EDTA to LAP doesn't influence the crystallinity. However, the transmittance and NLO properties significantly increase with EDTA additive and hence bulk LAP crystals are useful for laser fusion experiments.

Resource-efficient load-balancing framework for cloud data center networks

Kumar, Jitendra,Singh, Ashutosh Kumar,Mohan, Anand Electronics and Telecommunications Research Instit 2021 ETRI Journal Vol.43 No.1

Cloud computing has drastically reduced the price of computing resources through the use of virtualized resources that are shared among users. However, the established large cloud data centers have a large carbon footprint owing to their excessive power consumption. Inefficiency in resource utilization and power consumption results in the low fiscal gain of service providers. Therefore, data centers should adopt an effective resource-management approach. In this paper, we present a novel load-balancing framework with the objective of minimizing the operational cost of data centers through improved resource utilization. The framework utilizes a modified genetic algorithm for realizing the optimal allocation of virtual machines (VMs) over physical machines. The experimental results demonstrate that the proposed framework improves the resource utilization by up to 45.21%, 84.49%, 119.93%, and 113.96% over a recent and three other standard heuristics-based VM placement approaches.

Electrochemical studies on two-dimensional ZnInO nanoplates for organic–inorganic hybrid photodiode related applications

Mohan Kumar, G.,Madhan Kumar, A.,Ilanchezhiyan, P.,Kang, T.W. Elsevier 2015 JOURNAL OF ALLOYS AND COMPOUNDS Vol.619 No.-

<P><B>Abstract</B></P> <P>An ultra low cost route has been established to fabricate organic–inorganic hybrid <I>p</I> <I>–</I> <I>n</I> junctions <I>via</I> chemical <I>in-situ</I> polymerization of organic monomers on traditionally drop casted inorganic deposits. In this regard, ZnInO nanoplate-like structures were synthesized through a facile solution based chemical approach and their structural property was studied using X-ray diffraction patterns. The nature of charge carriers and donor density in ZnInO made electrodes were studied using electrochemical impedance spectroscopy. The dissemination of polymer matrices on the ZnInO nanoplates was examined through scanning electron microscopy. The current–voltage characteristics obtained across the polypyrrole/ZnInO made hybrid structures revealed an improved rectifying behaviour under illuminated conditions. The mechanism behind the drastic decrease in resistance values that substantiates the improved electron transfer characteristics across the organic–inorganic structures was studied through cyclic voltammetric measurements.</P>

Cortical Auditory Event Related Potentials (P300) for Frequency Changing Dynamic Tones

Mohan Kumar Kalaiah,Usha Shastri 대한청각학회 2016 Journal of Audiology & Otology Vol.20 No.1

Background and Objectives: P300 has been studied with a variety of stimuli. However, the nature of P300 has not been investigated for deviant stimuli which change its characteristics from standard stimuli after a period of time from onset. Subjects and Methods: Nine young adults with normal hearing participated in the study. The P300 was elicited using an oddball paradigm, the probability of standard and deviant stimuli was 80% and 20% respectively. Six stimuli were used to elicit P300, it included two pure-tones (1,000 Hz and 2,000 Hz) and four tone-complexes (tones with frequency changes). Among these stimuli, 1,000 Hz tone served as standard while others served as deviant stimuli. The P300 was recorded in five separate blocks, with one of the deviant stimuli as target in each block. Electroencephalographic was recorded from electrode sites Fz, Cz, C3, C4, and Pz. Latency and amplitude of components of the cortical auditory evoked potentials were measured at Cz. Results: Waveforms obtained in the present study shows that, all the deviant stimuli elicited obligatory P1-N1-P2 for stimulus onset. 2,000 Hz deviant tone elicited P300 at a latency of 300 ms. While, tone-complexes elicited acoustic change complex (ACC) for frequency changes and finally elicited P300 at a latency of 600 ms. In addition, the results showed shorter latency and larger amplitude ACC and P300 for rising tone-complexes compared to falling tone-complexes. Conclusions: Tone-complexes elicited distinct waveforms compared to 2,000 Hz deviant tone. Rising tone-complexes which had an increase in frequency elicited shorter latency and larger amplitude responses, which could be attributed to perceptual bias for frequency changes.

Solution processed n-In2O3nanostructures for organic-inorganic hybrid p-n junctions

Kumar, G. Mohan,Kumar, A. Madhan,Ilanchezhiyan, P.,Kang, T. W. The Royal Society of Chemistry 2014 Nanoscale Vol.6 No.19

<P>Solution processed organic-inorganic bulk hybrid heterostructures are nowadays considered as the most promising elements to perform efficient optoelectronic functions. In this regard, In2O3 based hybrid heterostructures were fabricated using polypyrrole and their role as efficient interfacial layers was studied using polypyrrole/ZnO nanowires. The In2O3 nanostructures were synthesized through a facile wet chemical approach at an average scale of less than 10 nm in cubic phase. The presence of O and In related defects was studied through emission spectra; these were also found to exhibit their predominance in Raman measurements. The n-type characteristics and donor density value of around 1020 cm-3 were evaluated for the In2O3 specimens via Mott-Schottky plots. The role of In2O3 nanostructures as active/interfacial layers was then studied using the current-voltage characteristics obtained across the hybrid heterostructures made of polypyrrole/In2O3, polypyrrole/ZnO and polypyrrole/In2O3/ZnO. Organic-inorganic p-n diodes were obtained via in situ chemical polymerization, drop casting and hydrothermal routes. Cyclic voltammograms and Nyquist plots were used to study the reduction mechanism taking place in the nanostructures that actually results with the formation of metallic In, which plays a vital role in establishing the required conduction electrons. The same has been reasoned for the improved rectification characteristics observed across the diodes.</P>

High performance photodiodes based on chemically processed Cu doped SnS₂ nanoflakes

Mohan Kumar, G.,Xiao, Fu,Ilanchezhiyan, P.,Yuldashev, Sh.,Madhan Kumar, A.,Cho, H.D.,Lee, D.J.,Kang, T.W. Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.455 No.-

<P><B>Abstract</B></P> <P>In this work, Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized through a simple hydrothermal method. The influence of Cu doping on the structural, optical and electrical properties of SnS<SUB>2</SUB> were investigated in detail. Optical properties explores the Cu doping in SnS<SUB>2</SUB> crystal lattice to result with a red-shift in absorption spectrum, which benefits visible-light absorption. Photodiodes were further fabricated by spin coating Cu doped SnS<SUB>2</SUB> nanoflakes on p-type silicon (Si). Electrical and photoelectrical parameters of Cu doped SnS<SUB>2</SUB> nanoflakes were determined by studying their impedance and current–voltage (I–V) characteristics, respectively. The diodes were found to exhibit excellent rectifying behavior and good sensitivity on par to pristine photodiodes. Impedance results identified the resistance of device to reduce considerably on Cu doping. The enhanced photoelectrical properties of the heterojunctions has been ascribed to Cu ions, which act as effective dopant and contribute to the varied carrier concentration in SnS<SUB>2</SUB>. Finally the obtained results suggest the potential of Cu-doped SnS<SUB>2</SUB> for application in photodetection and sensors applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu doped SnS<SUB>2</SUB> nanoflakes were synthesized in hexagonal phase. </LI> <LI> Nature of charge carriers/carrier density was determined using Mott-Schottky plots. </LI> <LI> Photodiode based on Cu doped SnS<SUB>2</SUB> nanoflakes were fabricated on p-Si substrate. </LI> <LI> Photodiode revealed improved photocurrent and responsitivity values under illumination. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Numerical analysis of pressure drop and temperature in a hairpin heat exchanger with different shell and tube bank arrangements

Mohan Kumar Dey,Nanjundan Parthasarathy,이연원 한국마린엔지니어링학회 2020 한국마린엔지니어링학회지 Vol.44 No.4

In this numerical study, the hairpin type shell and tube heat exchanger is analyzed for heating the cryogenic liquefied natu-ral gas (LNG). The cryogenic LNG is passed through the tube side and is heated by the hot water on the shell side of the hairpin heat exchanger. In order to increase the performance of the heat exchanger, maximum heat needs to be extracted from the hot water and transferred to the LNG stream. Thus, different arrangement of shell and tube sides of the hairpin heat exchanger are used to study the pressure drop in the hot water and to increase the temperature of the LNG. The effects of horizontal and vertical baffles orientation, staggered and aligned tube bank arrangements, baffles number (6, 8, 10 and 12), and baffles cut percentages were used to analyze the pressure drop and temperature difference in the exchanger. The results show that the pressure drop is decreased and the tube outlet temperature is increased in the heat exchanger for the percentage of baffle cut changes from 22.5% to 37.5%. Also, increasing the number of baffles increases both the temperature and pressure drop in the hairpin heat exchanger. Furthermore, comparing horizontal and vertical baffle orientation, pressure drop is always lower and LNG outlet temperature is always higher in the horizontal baffle orientation for both tube bank arrangement systems. However, in the horizontal baffle orientation the pressure drop for staggered tube bank arrangement is smaller than that of aligned tube bank arrangement, but the temperature of aligned tube bank is higher compared to the staggered tube bank arrangement.

Role of Active Listening and Listening Effort on Contralateral Suppression of Transient Evoked Otoacousic Emissions

Mohan Kumar Kalaiah,Nikhitha B Theruvan,Kaushlendra Kumar,Jayashree S Bhat 대한청각학회 2017 Journal of Audiology & Otology Vol.21 No.1

Background and Objectives: The present study aimed to investigate the effect of active listening and listening effort on the contralateral suppression of transient evoked otoacoustic emissions (CSTEOAEs). Subjects and Methods: Twenty eight young adults participated in the study. Transient evoked otoacoustic emissions (TEOAEs) were recorded using ‘linear’ clicks at 60 dB peSPL, in three contralateral noise conditions. In condition 1, TEOAEs were obtained in the presence of white noise in the contralateral ear. While, in condition 2, speech was embedded into white noise at +3, -3, and -9 dB signal-tonoise ratio (SNR) and delivered to the contralateral ear. The SNR was varied to investigate the effect of listening effort on the CSTEOAE. In condition 3, speech was played backwards and embedded into white noise at -3 dB SNR. The conditions 1 and 3 served as passive listening condition and the condition 2 served as active listening condition. In active listening condition, the participants categorized the words in to two groups (e.g., animal and vehicle). Results: CSTEOAE was found to be largest in the presence of white noise, and the amount of CSTEOAE was not significantly different between active and passive listening conditions (condition 2 and 3). Listening effort had an effect on the CSTEOAE, the amount of suppression increased with listening effort, when SNR was decreased from +3 dB to -3 dB. However, when the SNR was further reduced to -9 dB, there was no further increase in the amount of CSTEOAE, instead there was a reduction in the amount of suppression. Conclusions: The findings of the present study show that listening effort might affect CSTEOAE.

Electrical property studies on chemically processed polypyrolle/aluminum doped ZnO based hybrid heterostructures

Mohan Kumar, G.,Ilanchezhiyan, P.,Madhan Kumar, A.,Yuldashev, Sh.U.,Kang, T.W. Elsevier 2016 Chemical physics letters Vol.649 No.-

<P>A hybrid structure based on p-type polypyrolle (PPy) and n-type aluminum (Al) doped ZnO nanorods was successfully constructed. The effect of Al doping on material properties of wurtzite structured ZnO were studied using several analytical techniques. To establish the desired hybrid structure, pyrrole monomers were polymerized on hydrothermally grown Al doped ZnO nanorods by chemical polymerization. The current-voltage characteristics on the fabricated PPy/A1 doped ZnO heterostructures were found to exhibit excellent rectifying characteristics under dark and illumination conditions. The obtained results augment the prescribed architecture to be highly suitable for high-sensitivity optoelectronic applications. (C) 2016 Elsevier B.V. All rights reserved.</P>