15 results on '"Kumar, A. Sendil"'
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2. Tailoring the properties of spray deposited V2O5 thin films using swift heavy ion beam irradiation
- Author
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Rathika, R., Kovendhan, M., Joseph, D. Paul, Pachaiappan, Rekha, Kumar, A. Sendil, Vijayarangamuthu, K., Venkateswaran, C., Asokan, K., and Jeyakumar, S. Johnson
- Published
- 2020
- Full Text
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3. 200 MeV Ag15+ ion beam irradiation induced modifications in spray deposited MoO3 thin films by fluence variation
- Author
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Rathika, R., Kovendhan, M., Joseph, D. Paul, Vijayarangamuthu, K., Kumar, A. Sendil, Venkateswaran, C., Asokan, K., and Jeyakumar, S. Johnson
- Published
- 2019
- Full Text
- View/download PDF
4. Spontaneous exchange bias effect in superparamagnetic LaFeO3 nanoparticles
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Kumar, A. Sendil and Bhatnagar, Anil K
- Published
- 2017
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5. Signal Conducting System with Effective Optimization Using Deep Learning for Schizophrenia Classification.
- Author
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Divya, V., Kumar, S. Sendil, Krishnan, V. Gokula, and Kumar, Manoj
- Subjects
SIGNAL processing ,DEEP learning ,ELECTROENCEPHALOGRAPHY ,DIAGNOSIS of schizophrenia ,CONVOLUTIONAL neural networks - Abstract
Signal processing based research was adopted with Electroencephalogram (EEG) for predicting the abnormality and cerebral activities. The proposed research work is intended to provide an automatic diagnostic system to determine the EEG signal in order to classify the brain function which shows whether a person is affected with schizophrenia or not. Early detection and intervention are vital for better prognosis. However, the diagnosis of schizophrenia still depends on clinical observation to date. Without reliable biomarkers, schizophrenia is difficult to detect in its early phase and hence we have proposed this idea. In this work, the EEG signal series are divided into non-linear feature mining, classification and validation, and t-test integrated feature selection process. For this work, 19-channel EEG signals are utilized from schizophrenia class and normal pattern. Here, the datasets initially execute the splitting process based on raw 19-channel EEG into 6250 sample point's sequences. With this process, 1142 features of normal and schizophrenia class patterns can be obtained. In other hand, 157 features from each EEG patterns are utilized based on Non-linear feature extraction process where 14 principal features can be identified in terms of considering the essential features. At last, the Deep Learning (DL) technique incorporated with an effective optimization technique is adopted for classification process called a Deep Convolutional Neural Network (DCNN) with mayfly optimization algorithm. The proposed technique is implemented into the platform of MATLAB in order to obtain better results and is analyzed based on the performance analysis framework such as accuracy, Signal to Noise Ratio (SNR), Mean Square Error, Normalized Mean Square Error (NMSE) and Loss. Through comparison, the proposed technique is proved to a better technique than other existing techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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6. A Rare Case of Pediatric Intraparenchymal Epidermoid Cyst: Case Report and Review of Literature
- Author
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Kannan, Satish, Kumar, A. Sendil, and Syamala, S.
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intraparenchymal ,pediatric ,integumentary system ,otorhinolaryngologic diseases ,Case Report ,Epidermoid cysts ,respiratory system ,neoplasms ,respiratory tract diseases - Abstract
Epidermoid cysts are slow-growing benign tumors that represent less than 1–2% of all intracranial tumors. They are even rarer in supratentorial intraparenchymal location accounting for 2% of all intracranial epidermoid cysts. We present a rare case of pediatric supratentorial intraparenchymal epidermoid cyst with its variable radiographic features, surgical management, histopathology, and a review of the literature.
- Published
- 2018
7. Tailoring the properties of spray deposited V2O5thin films using swift heavy ion beam irradiation
- Author
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Rathika, R., Kovendhan, M., Joseph, D. Paul, Pachaiappan, Rekha, Kumar, A. Sendil, Vijayarangamuthu, K., Venkateswaran, C., Asokan, K., and Jeyakumar, S. Johnson
- Abstract
Swift heavy ion (SHI) beam irradiation can generate desirable defects in materials by transferring sufficient energy to the lattice that favours huge possibilities in tailoring of materials. The effect of Ag15+ion irradiation with energy 200 MeV on spray deposited V2O5thin films of thickness 253 nm is studied at various ion doses from 5 × 1011to 1 × 1013ions/cm2. The XRD results of pristine film confirmed orthorhombic structure of V2O5and its average crystallite size was found to be 20 nm. The peak at 394 cm−1in Raman spectra confirmed O–V–O bonding of V2O5, whereas 917 cm−1arise because of distortion in stoichiometry by a loss of oxygen atoms. Raman peaks vanished completely above the ion fluence of 5 × 1012ions/cm2. Optical studies by UV–Vis spectroscopy shows decrement in transmittance with an increase in ion fluence up to 5 × 1012ions/cm2. The red shift is observed both in the direct and indirect band gaps until 5 × 1012ions/cm2. The surface topography of the pristine film revealed sheath like structure with randomly distributed spherical nano-particles. The roughness of film decreased and the density of spherical nanoparticles increased upon irradiation. Irradiation improved the conductivity significantly for fluence 5 × 1011ions/cm2due to band gap reduction and grain growth.
- Published
- 2020
- Full Text
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8. 200 MeV Ag15+ion beam irradiation induced modifications in spray deposited MoO3thin films by fluence variation
- Author
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Rathika, R., Kovendhan, M., Joseph, D. Paul, Vijayarangamuthu, K., Kumar, A. Sendil, Venkateswaran, C., Asokan, K., and Jeyakumar, S. Johnson
- Abstract
Spray deposited Molybdenum trioxide (MoO3) thin film of thickness nearly 379 nm were irradiated with 200 MeV Ag15+ion beam at different fluences (Ø) of 5 × 1011, 1 × 1012, 5 × 1012and 1 × 1013ions/cm2. The X-ray diffraction (XRD) pattern of the pristine film confirms orthorhombic structure and the crystallinity decreased after irradiation with the fluence of 5 × 1011ions/cm2due to irradiation induced defects and became amorphous at higher fluence. In pristine film, Raman modes at 665, 820, 996 cm−1belong to Mo–O stretching, 286 cm−1belong to Mo–O bending mode and those below 200 cm−1are associated with lattice modes. Raman peak intensities decreased upon irradiation and vanished completely for the ion fluence of 5 × 1012ions/cm2. The percentage of optical transmittance of pristine film was nearly 40%, while for irradiated films it decreased significantly. Red shift was observed for both the direct and indirect band gaps. The pristine film surface had densely packed rod like structures with relatively less porosity. Surface roughness decreased significantly after irradiation. The electrical transport properties were also studied for both the pristine and irradiated films by Hall effect. The results are discussed.
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- 2019
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9. Magnetism from Fe2O3 nanoparticles embedded in amorphous SiO2 matrix.
- Author
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Kumar, A. Sendil and Bhatnagar, Anil K.
- Subjects
MAGNETISM ,FERRIC oxide ,SILICA ,NANOPARTICLES ,MICROSTRUCTURE - Abstract
Fe
2 O3 nanoparticles are embedded in amorphous SiO2 matrix by coprecipitation method with varying concentrations. Conditions are optimized to get almost monodispersed Fe2 O3 nanoparticles with high chemical stability. Microstructure of synthesized nanoparticles is well characterized and found that Fe2 O3 is in nanocrystalline form and embedded uniformly in amorphous SiO2 matrix. Enhanced surface reactivity is found for nanoparticles which influences physical properties of the SiO2 supported Fe2 O3 system due to adsorption. In oxide nanoparticles, significant number of defect sites at the surface is expected but when supported medium such as SiO2 it reduces this defect concentration. Field- and temperature-dependent magnetisation studies on these samples show superparamagnetic behaviour. Superparamagnetic behaviour is seen in all the concentration systems but the coercivity observed in the lower concentration systems is found to be anomalous compared to that of higher concentrations. The observed magnetic behaviour comes from either unsaturated bond existing due to the absence of anions at the surface of nanoparticles or reconstruction of atomic orbitals taking place at interface of Fe2 O3 - SiO2 system. [ABSTRACT FROM AUTHOR]- Published
- 2018
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10. Small business behavior: development and test of a multivariate model
- Author
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Kumar, E. Sendil, Chhokar, Jagdeep S., Misra, Sasi B., and Ramnarayan, S.
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Performance networking behaviour ,Small business - Abstract
Small businesses have been the subject of research interest in at least three independent fields of inquiry: economics, entrepreneurship, and life cycle theory. However, a review of the literature indicates: (1) the absences of theory to explain small firm behavior; and, (2) little knowledge about what differentiates high performing small firms from their low performing counterparts. In the light of these gaps, the study converged on the broad objective of development and testing a model of small business behavior which embraced five research questions: (1) How do environmental characteristics influence the structures, strategies, networking behavior and performance of small business? (2) Is networking a significant explanatory of small business performance? (3) How does management of small business influence performance? (4) Does an entrepreneurial orientation contribute to high performance? (5) Does fit among the environmental elements and characteristics explains performance differences of small businesses? The study, adopting a survey design collected data from 126 small manufacturing firms in three states: Gujarat, Maharashtra, and Tamil Nadu. For each firm the owner/entrepreneur responded to a questionnaire designed for the study. Psychometric properties of the measures employed in the investigation were assessed through item analyses and moderated multiple regression analyses. Structural equation modeling was attempted to uncover preliminary relationships through the major constructs in the research framework. Some of the significant findings among others include: • In environments characterized by low efficiency, firms adopting differentiation strategies report higher performance than firms following cost leadership or focus strategies. • The interaction of environmental opportunity and uncertainty is positively associated with customer and supplier networking. While environmental uncertainty is positively associated with customer and supplier networking, under added conditions of high environmental opportunity, firms apparently have a greater impetus to engage in networking behavior. • High environmental opportunity is positively associated with personal networking. When high opportunity is perceived in the environment, firms attempt to exploit the opportunity through personal networking. • The interaction of environmental opportunity and uncertainty is positively related to organizational innovativeness. Environmental uncertainty is unrelated to organizational innovativeness; however, under added conditions of high environmental opportunity, there is stimulus to reduce uncertainty and unpredictability through increased innovative behavior. • The interaction of environmental opportunity and inefficiency is positively related to organizational innovativeness. Again environmental opportunity is unrelated to organizational innovativeness; however, under added conditions of low environmental efficiency, there is a clear proclivity for innovative behavior. • Environmental opportunity is positively related to firm performance. This is consistent with the normative organization theory literature which posits that under conditions of high environmental munificence (i.e., high growth potential, resource abundance, infrastructure availability etc.) performance of firms is likely to be higher than conditions of environmental scarcity. • Innovative differentiation is positively related to the use of formal systems in the organization, but unrelated to the extent to which rules are employed. This is contrary to the behavior of large organizations where it is found that in general, innovative differentiation is related to organic structures characterized by few rules and systems, i.e., low levels of formalization. However, in the present study the finding that innovative differentiation is positively associated with systems but unrelated to rules and procedures suggests that small firms will benefit from the creation and maintenance of good systems regardless of the type of business strategy pursued. • Cost leadership strategy is strongly related to both rules and systems in the organization. This finding is consistent with the literature. Cost leadership strategy is associated with cost cutting, and reliance on monitoring and control systems geared to maximize efficiency all of which point to existence of organizational relationship and transactions bound through strong rules and systems. • Personal networking is positively associated with proactiveness and competitive aggressiveness. Proactiveness and competitive aggressiveness are two critical dimensions of firms’ entrepreneurial orientation. Therefore, strong entrepreneurial orientation related to personal networking suggests that the latter may also be an important dimension of entrepreneurial behavior. • Personal networking is positively associated with both profitability and competitive performance. Personal networking has direct positive relationship with both dimensions of performance suggesting that small firm owner/managers who engage in networking behaviors consistently report higher performance than their counterpart who do not engage in networking. Some of the implications include: • The study has found preliminary support for the fit/congruence perspective of organization theory. This perspective posits that high performance is engendered through fit between environment, and organizational elements. The prescription for organization theorists and researchers working under the rubric of this perspective is to investigate the unique configuration of design elements which result in high performance. In the case of small firm behavior the present finding is an important step toward grounded theory-building. This will help in moving towards the ultimate goal of a theory of small business management. • The study has found support for the assertion of a small but burgeoning stream of literature that networking is a critical factor explaining the success of small and entrepreneurial firms. Given this finding small firm owner/managers may find it useful to develop networks which will not only help in reducing supply and demand side uncertainties but also aid in meeting the numerous regulatory requirements, obtaining clearances, accessing distribution channels, obtaining finance and so on. • Science, networking has emerged as an important variable explaining small business performance, it may be useful for small industry associations to devote efforts to providing the services that the entrepreneurs obtain through networks. This will help reduce the time spent by entrepreneurs obtain through networks. This will help reduce the time spent by entrepreneurs on such boundary management activities. The study concludes with a discussion of the study limitations and several pointers to future research.
- Published
- 1999
11. catena-Poly[ammonium (cadmium-tri-μ-thiocyanato-κ4S:N;κ2N:S)–1,4,10,13,16-hexaoxacyclooctadecane (1/1)]
- Author
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Ramesh, V., primary, Rajarajan, K., additional, Kumar, K. Sendil, additional, Subashini, A., additional, and NizamMohideen, M., additional
- Published
- 2012
- Full Text
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12. Magnetic and ferroelectric properties of Fe doped SrTiO3-δfilms
- Author
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Kumar, A Sendil, primary, Suresh, P, additional, Kumar, M Mahesh, additional, Srikanth, H, additional, Post, M L, additional, Sahner, Kathy, additional, Moos, Ralf, additional, and Srinath, S, additional
- Published
- 2010
- Full Text
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13. The eschar of scrub typhus
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Sivabalan So and Kumar D. Sendil
- Subjects
medicine.medical_specialty ,business.industry ,Pediatrics, Perinatology and Child Health ,medicine ,Scrub typhus ,Eschar ,medicine.symptom ,medicine.disease ,business ,Dermatology ,Typhus - Published
- 2010
14. Exchange bias effect in Ti doped nanocrystalline SrFeO3-δ.
- Author
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Kumar, A. Sendil and Srinath, S.
- Subjects
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ION exchange (Chemistry) , *NANOCRYSTALS , *TITANIUM , *DOPED semiconductors , *MAGNETIZATION - Abstract
Materials of Ti doped nanocrystalline SrFeO3-δ were synthesized through solid state reaction. Detailed magnetization measurements were carried out in zero field cooled (ZFC) and field cooled (FC) conditions. Compounds of SrFe1-xTixO3-δ (x = 0.1 to 0.3) are found to be spin glass and parent compound is a helical antiferromagnet. Non magnetic Ti4+ reduces the strength of exchange interactions and the curvature of hysteresis is changed towards concave nature. Exchange bias is observed below the peak temperature (irreversibility in magnetization (TIrr)) in ZFC-FC of SrFe1-xTixO3-δ (x = 0 to 0.3). The coercivity and exchange bias field values are found to be decreases with increase in temperature. Observed exchange bias effect is attributed to competition between antiferromagnetic superexchange and ferromagnetic double exchange interactions. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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15. Exchange bias effect in Ti doped nanocrystalline SrFeO3-δ.
- Author
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Kumar, A. Sendil and Srinath, S.
- Subjects
ION exchange (Chemistry) ,NANOCRYSTALS ,TITANIUM ,DOPED semiconductors ,MAGNETIZATION - Abstract
Materials of Ti doped nanocrystalline SrFeO
3-δ were synthesized through solid state reaction. Detailed magnetization measurements were carried out in zero field cooled (ZFC) and field cooled (FC) conditions. Compounds of SrFe1-x TixO3-δ (x = 0.1 to 0.3) are found to be spin glass and parent compound is a helical antiferromagnet. Non magnetic Ti4+ reduces the strength of exchange interactions and the curvature of hysteresis is changed towards concave nature. Exchange bias is observed below the peak temperature (irreversibility in magnetization (TIrr)) in ZFC-FC of SrFe1-x TixO3-δ (x = 0 to 0.3). The coercivity and exchange bias field values are found to be decreases with increase in temperature. Observed exchange bias effect is attributed to competition between antiferromagnetic superexchange and ferromagnetic double exchange interactions. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
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