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Search Results: 1 - 10 of 329371 matches for " V. R. Meenakshi "
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Fast DOA estimation using wavelet denoising on MIMO fading channel
A. V. Meenakshi,V. Punitham,R. Kayalvizhi,S. Asha
Mathematics , 2011,
Abstract: This paper presents a tool for the analysis, and simulation of direction-of-arrival (DOA) estimation in wireless mobile communication systems over the fading channel. It reviews two methods of Direction of arrival (DOA) estimation algorithm. The standard Multiple Signal Classification (MUSIC) can be obtained from the subspace based methods. In improved MUSIC procedure called Cyclic MUSIC, it can automatically classify the signals as desired and undesired based on the known spectral correlation property and estimate only the desired signal's DOA. In this paper, the DOA estimation algorithm using the de-noising pre-processing based on time-frequency conversion analysis was proposed, and the performances were analyzed. This is focused on the improvement of DOA estimation at a lower SNR and interference environment. This paper provides a fairly complete image of the performance and statistical efficiency of each of above two methods with QPSK signal.
Hydro- Chemical Evolution of Palk Strait Region, Bay of Bengal
chinavenkataraman govindasamy,Mani Arulpriya,Packiasamy Ruban,V. R. Meenakshi
Journal of Tropical Life Science , 2012,
Abstract: Present analysis was carried out the physico- chemical parameters of two stations such as Thondi and Soliyakudi in the southeast Palk Strait region during the monsoon and post monsoon seasons (November 2008 – March 2009). High temperature (31 C) and salinity (35%o) was recorded in the month of March (post monsoon). Dissolved oxygen content was high (5.2 O2 mg. l-1) during in the monsoonal season. Compared with other nutrients such as NO3, NO2 and SiO2, the total phosphorous concentration was high in both the stations during monsoonal season. In general concentrations of all the nutrients were high in the station I during monsoon season (November and December) which could be due to the addition of nutrients through the sewage, agricultural and land run off.
Fast DOA estimation using wavelet denoising on MIMO fading channel
A.V. Meenakshi,V.Punitham,,R.Kayalvizhi,S.Asha
International Journal of Multimedia & Its Applications , 2011,
Abstract: This paper presents a tool for the analysis, and simulation of direction-of-arrival (DOA) estimation inwireless mobile communication systems over the fading channel. It reviews two methods of Direction ofarrival (DOA) estimation algorithm. The standard Multiple Signal Classification (MUSIC) can be obtainedfrom the subspace based methods. In improved MUSIC procedure called Cyclic MUSIC, it canautomatically classify the signals as desired and undesired based on the known spectral correlationproperty and estimate only the desired signal’s DOA. In this paper, the DOA estimation algorithm usingthe de-noising pre-processing based on time-frequency conversion analysis was proposed, and theperformances were analyzed. This is focused on the improvement of DOA estimation at a lower SNR andinterference environment. This paper provides a fairly complete image of the performance and statisticalefficiency of each of above two methods with QPSK signal.
Performance Analysis of Proprietary and Non-Proprietary Software
R. Thirumalai Selvi,R.Meenakshi,N. V. Balasubramanian,George T. Manohar
Lecture Notes in Engineering and Computer Science , 2008,
Abstract:
Improving Prediction Accuracy in Context Aware Smart Homes Using K-Markov Model
A.S. Meenakshi Sundaram,M. Mahesh Babu,C. Manikandan,V. Rhymend Uthariaraj,R. Shriram
International Journal of Soft Computing , 2012,
Abstract: Context awareness is a term that refers to knowledge of where, when and what the user does. The study implements all the above forms of context awareness, using only RFIDs in contrast to various expensive technologies like video/audio sensing, pressure pads etc. The paper implements the next room prediction of users based on Fuzzy Timed K-Markov model. Various values of K have been used and the optimal value is suggested. The study also models the uncertainty of user behavior recognition using Bayesian Belief Networks (BBNs) and predicts the user`s action using negative reinforcement learning technique. Unlike in previous models where the implementations invariably had the users wear the tags, or the Bracelet readers, but, we use a combination of both as it seemed to help us derive hierarchical contextual information, that is, the context changes that accompany people interacting with each other. The model is also unobtrusive during the learning period. The study in all, aims to realize a context aware Ambient Intelligent system in Smart Home though RFIDs.
Performance comparison of wavelet denoising based fast DOA estimation of MIMO OFDM system over Rayleigh Fading Channel
A.V.Meenakshi,R.Kayalvizhi,S.Asha
International Journal of Multimedia & Its Applications , 2012,
Abstract: This paper presents a tool for the analysis, and simulation of direction-of-arrival estimation for MIMO OFDM signal over the Rayleigh fading channel. The performance of the proposed technique is tested for wavelet denoising based CYCLIC MUSIC algorithm. Simulation results demonstrate that the proposed system not only has good ability of suppressing interference, but also significantly improves the DOA estimation of the system. In this paper, it is proposed to find DOA of the received MIMO OFDM signal, and the performances are analyzed using matlab simulation by the Monte Carlo computer iteration. This paper provides a fairly complete image of the performance and statistical efficiency with QPSK signal model for coherent system at a lower SNR(18dB) and interference environment.
Drug Utilization Study in Outpatient Ophthalmology Department of Government Medical College Jammu
Meenakshi Nehru, K. Kohli, B. Kapoor, P. Sadhotra, V. Chopra, R. Sharma
JK Science : Journal of Medical Education & Research , 2005,
Abstract: The present study was undertaken to assess the patterns of prescription and drug utilization bymeasuring WHO delineated drug use indicators. This study was conducted in the PostgraduateDepartment of Pharmacology and Therapeutics in collaboration with the Postgraduate Departmentof Ophthalmology Govt. Medical College Hospital, Jammu. Total number of prescriptions analyzedwere 440 , in which total of 822 drugs were prescribed. Analysis of the prescriptions showed thataverage number of drugs per prescription was 1.87. The maximum number of drugs prescribed werein the form of eye drops (66.18%), followed by ointments (16%), capsules (9.5%), tablet (6.57%),syrup (0.73%), injection (0.73%) and lotion (0.24%). The dosage form was indicated for 94%,frequency of drug administration for 98% drugs and duration of treatment for only 75% of the drugsprescribed. The number of antibiotics prescribed was 266 (32.26%), out of these 160 (60.15%)antibiotics prescribed in the form of drops, 100 (37.59%) as ointment and 6 (2.26%) orally. Numberof encounters with anti-inflammatory and antiallergic drugs was 92 (11.2%), mydriatics and cycloplegics64(7.9%), miotics 20 (2.4%), multivitamins 58 (7.05%) andothers used were lubricant and miscellaneouseye drops 322 (40%). Common prescription writing errors were minimum and there was no evidence ofpolypharmacy. However, duration of treatment and prescribing by generic name was very low.
Enhanced Magnetic Anisotropy of Mn12-acetate
D. M. Seo,V. Meenakshi,W. Teizer,H. Zhao,K. R. Dunbar
Physics , 2005, DOI: 10.1016/j.jmmm.2005.06.005
Abstract: Thin films of the Single Molecule Magnet (Mn12-acetate) have been fabricated on a Si-substrate by the Dip-and-Dry method, a simple and robust technique. Atomic force microscopy and X-ray photoelectron spectroscopy characterizations reveal that homogeneous, thin films of a few molecular layers with smoothness at the molecular level are deposited. Significant changes in magnetic properties of Mn12-acetate exposed to the same solvent were observed in zero-field-cooled and field-cooled magnetization, as well as ac-susceptibility measurements. The blocking temperature was found to increase to TB > 10 K at low magnetic fields, indicating an enhanced magnetic anisotropy.
Mn12-acetate film pattern generated by photolithography methods
K. Kim,D. M. Seo,J. Means,V. Meenakshi,W. Teizer,H. Zhao,K. R. Dunbar
Physics , 2004, DOI: 10.1063/1.1808492
Abstract: We demonstrate a straightforward way to lithographically fabricate Mn12-acetate (Mn12O12(CH3COO)16(H2O)4 2CH3COOH 4H2O) thin film patterns on Si/SiO2 surfaces, a significant step in light of the chemical volatility of this organic complex. Atomic force microscopy (AFM) images of the film patterns allow the determination of the pattern dimensions. X-ray photoelectron spectroscopy (XPS) data indicate that the patterned material is the intact Mn12-acetate complex. Magnetic measurements of the Mn12-acetate film confirm that the film properties are reminiscent of crystalline Mn12-acetate, suggesting that this approach can be used to fabricate lithographically patterned devices of Mn12-acetate.
Films of Mn12-acetate by Pulsed Laser Evaporation
V. Meenakshi,W. Teizer,D. G. Naugle,H. Zhao,K. R. Dunbar
Physics , 2004, DOI: 10.1016/j.ssc.2004.08.019
Abstract: Films of the molecular nanomagnet, Mn12-acetate, have been deposited using pulsed laser deposition and a novel variant, matrix assisted pulsed laser evaporation. The films have been characterized by X-ray photoelectron spectroscopy, mass spectrometry and magnetic hysteresis. The results indicate that an increase in laser energy and/or pulse frequency leads to fragmentation of Mn12, whereas its chemical and magnetic integrity is preserved at low laser energy (200 mJ). This technique allows the fabrication of patterned thin film systems of molecular nanomagnets for fundamental and applied experiments.
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