Design and implementation of fast output sampling feedback control for shape memory alloy actuated structures

Dhanalakshmi, K.,Umapathy, M.,Ezhilarasi, D.,Bandyopadhyay, B. Techno-Press 2011 Smart Structures and Systems, An International Jou Vol.8 No.4

This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of $Simulink^{TM}$ modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

Effect of ethanolic extract of some anti-asthmatic herbs on clonidine and haloperidol-induced catalepsy in mice

Dhanalakshmi, S.,Khaserao, S.S.,Kasture, S.B. Kyung Hee Oriental Medicine Research Center 2004 Oriental pharmacy and experimental medicine Vol.4 No.2

The ethanolic extract of some medicinal plants having anti-asthmatic activity such as Solanum xanthocarpum, Curcuma longa, Glycyrrhiza glabra, Piper longum, A. vasica, A. lebbeck, and Tinospora cordifolia was evaluated for antihistaminic and anti-cataleptic activity. The aqueous solution of ethanolic extract of S. xanthocarpum and G. glabra potentiated histamine-induced tracheal chain contractions. Whereas, C. longa, P. longum, and T. cordifolia, and A. lebbeck were without any significant effect on histamine. Only A. vasica inhibited histamine-induced tracheal chain contraction. G. glabra per se produced contraction of the tracheal chain, which was blocked by pretreatment with atropine. Single dose of S. xanthocarpum potentiated clonidine-induced catalepsy but on repeated doses (once in a day for 3 days) inhibited catalepsy. Pretreatment with ethanolic extract of C. longa, P. longum, T. cordifolia inhibited catalepsy whereas G. glabra and A. lebbeck significantly potentiated clonidine-induced catalepsy. None of the extracts inhibited haloperidol-induced catalepsy. Thus the extracts having antihistaminic activity or mast cell stabilizing activity inhibited clonidineinduced catalepsy.

Enhanced Ferromagnetic Order in Mn Doped BiFeO₃—Ni_0.5Zn_0.5Fe₂O₄ Multiferroic Composites

Dhanalakshmi, B.,Rao, P. S. V. Subba,Rao, B. Parvatheeswara,Kim, CheolGi American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.10

<P>Multiferroic composites of 0.5 BiFeO3-0.5Ni(0.5)Zn(0.5)Fe(2)O(4) and 0.5Bi(0.95)Mn(0.05)FeO(3)-0.5 Ni0.5Zn0.5Fe2O4 were prepared by combining sol-gel autocombustion and solid state methods. X-ray diffraction analysis of the composites reveals that the samples are formed as di-phase compounds while retaining the spinel phase for the Ni-Zn ferrite and perovskite phase for the Bi-ferrite. Fourier transform infrared spectroscopy measurements on the composites confirm their structures with the presence of Fe-O and Bi-O bonds. Dielectric measurements on the composites were used to discuss about the possible polarization/conduction mechanisms, phase transitions and magnetoelectric coupling. Room temperature ferroelectric and magnetic hysteresis loop studies on the samples ensure that the Mn doped composite exhibits enhanced remnant polarization as well as saturation magnetization compared to the undoped composite. Moreover, the Mn doping has further translated the composite into magnetically softened with coercivity almost close to zero. The obtained improvements in the dielectric and multiferroic properties of the composites are attributed to the corresponding structural modifications brought about by the Mn doping.</P>

Combined spatial temporal based In-loop filter for scalable extension of HEVC

Dhanalakshmi. A,Nagarajan G. 한국통신학회 2020 ICT Express Vol.6 No.4

Deep learning plays a major role in the present video processing tools and algorithms. To​ alleviate the limitations of present in-loop filters in the scalable extension of HEVC (SHVC), a combined residual network (CResNet) in-loop filtering is proposed in this paper. The proposed CResNet in-loop filter exploits layer information available in the spatial temporal domain to restrain the visual artifacts like blocking and ringing. Particularly, the block information related to current and co-located blocks of the spatial and temporal base layer reference frames are considered to optimize the in-loop filtering. The proposed architecture has four convolution layers at the base layer and two convolution layers at the enhancement layer that significantly reduces the coding complexity and memory. Additionally to completely train the input content and also to enhance the in-loop filter performance, the on/off level control flag for coding tree Unit (CTU) is sensed using rate distortion optimization (RDO) approach. The experimental results demonstrate that the proposed architecture provides up to 6.2% to 7.2% reduction in bit rate and 1.01 dB improvement in PSNR compared to the standard SHVC codec.

SHVC performance enhancement using superior step search algorithm

Dhanalakshmi. A,Nagarajan G.,Balaji. L 한국통신학회 2019 ICT Express Vol.5 No.3

The SHVC (Scalable High Efficiency Video Coding) standard developed as an extension to H.265 HEVC (High Efficiency Video Coding) that focus on data transmission over heterogeneous network with wide scalability. In this paper a Superior Step Search (SSS) algorithm is proposed to enhance the PSNR performance along with coding efficiency without much increase in the computational complexity. The proposed SSS algorithm performs dynamic search to predict the best matching block using a fine search pattern. Simulation results show 0.5% average increased performance in PSNR and 32% coding efficiency in Bit rate when compared with the SHM reference software.

A review of emergent intelligent systems for the detection of Parkinson’s disease

Samiappan Dhanalakshmi,Ramesh Sai Maanasaa,Ramesh Sai Maalikaa,Ramalingam Senthil 대한의용생체공학회 2023 Biomedical Engineering Letters (BMEL) Vol.13 No.4

Parkinson’s disease (PD) is a neurodegenerative disorder affecting people worldwide. The PD symptoms are divided intomotor and non-motor symptoms. Detection of PD is very crucial and essential. Such challenges can be overcome by applyingartificial intelligence to diagnose PD. Many studies have also proposed the implementation of computer-aided diagnosisfor the detection of PD. This systematic review comprehensively analyzed all appropriate algorithms for detecting andassessing PD based on the literature from 2012 to 2023 which are conducted as per PRISMA model. This review focused onmotor symptoms, namely handwriting dynamics, voice impairments and gait, multimodal features, and brain observationusing single photon emission computed tomography, magnetic resonance and electroencephalogram signals. The significantchallenges are critically analyzed, and appropriate recommendations are provided. The critical discussion of this reviewarticle can be helpful in today's PD community in such a way that it allows clinicians to provide proper treatment and timelymedication.

Design and implementation of fast output sampling feedback control for shape memory alloy actuated structures

K. Dhanalakshmi,M. Umapathy,D. Ezhilarasi,B. Bandyopadhyay 국제구조공학회 2011 Smart Structures and Systems, An International Jou Vol.8 No.4

This paper presents the design and experimental evaluation of fast output sampling feedback controller to minimize structural vibration of a cantilever beam using Shape Memory Alloy (SMA) wires as control actuators and piezoceramics as sensor and disturbance actuator. Linear dynamic models of the smart cantilever beam are obtained using online recursive least square parameter estimation. A digital control system that consists of Simulink modeling software and dSPACE DS1104 controller board is used for identification and control. The effectiveness of the controller is shown through simulation and experimentation by exciting the structure at resonance.

Computational Analysis of Apolipophorin-III in Hyphantria cunea

Chandrasekar R.,Dhanalakshmi R.,Krishnan M.,Kim H. J.,Jeong H. C.,Seo S. J. Korean Society of Sericultural Science 2005 International Journal of Industrial Entomology Vol.10 No.1

Recently a cDNA clone of apoLp-III from Hyphantria cunea was isolated and subjected to computational analysis to compare with other available sequences. Multiple sequence alignments were carried out using the amino acid sequences of apoLp-III from six insects. It was found that the H. cunea apoLp-III has relatively high sequence identities to Spodoptera litura ($69.5\%$), Manduca sexta ($66.8\%$), Galleria mellonella ($65.1\%$), Bombyx mori N4 ($54.3\%$) but less identity to Locusta migratoria ($18.3\%$). The amino acid composition was compared with other insects using EXPASY tools; it shows that alanine (Ala), glutamine (Gln), leucine (Leu) and lysine (Lys) are the major amino acid components of apoLp-III in H. cunea as well as other lepidopterans. Homology modeling performed using PSI-BLAST (PDB template M. sexta) reveals that the apoLp-III molecules consist of five, long amphipathic alpha helical bundles with short loops connecting the helices and shows homology with other insects. Phylogenetic analysis shows that the orthopteran apoLp-III represented by locust was most distantly related to the lepidopteran insects.

Spin Route Flipping in FeCo/RR-P3HT/ NiFe Organic Spin-Valve Device.

Manikandan Gunasekaran,Dhanalakshmi Dhandapani,Manivel Raja Muthuvel 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.2

An organic semiconductor (OSC) is a potential material in spintronics which is posses a long spin diff usion length due toits low spin-orbit coupling and hyperfi ne interaction. Among the OSC P3HT that already exists, in spintronic devices. Inthis report, An organic spin valve (OSV) device was fabricated using Regioregular Poly 3-hexylthiophene-2,5- diyl (RRP3HT). The RR-P3HT was used as a spacer layer, with FeCo and NiFe used as bottom and top electrodes, respectively. The device magnetoresistance (MR) was observed to be a positive MR of 2.9% at 50 K while negative MR of 0.6, 0.4,and 0.014% were observed at 150, 200, and 300 K, respectively. Observed AMR is positive at room temperature for Fecoand NiFe single layer as 0.08 and 0.18%, respectively. The magnetic electrodes were prepared using Ultra High VacuumDC magnetron sputtering, and RR-P3HT was prepared using a spin coater. The magnetic properties of the device werestudied by vibrating sample magnetometer (VSM) analysis. The VSM results conclude that both electrodes are magneticmaterials with diff erent coercive forces. The FeCo and NiFe, both electrodes crystal structures were analyzed from GracingIncidence X-Ray Diff raction (GI-XRD) using Cobalt K alpha. FeCo and NiFe were the Body-Centered Cubic crystalstructures, and the electrode’s JCPDS card numbers are 50–0795 and 37–0474, respectively.

Structural and Magnetic Characterizations of Ni—Zn—Co Ferrite Nanoparticles Synthesized by Sol—Gel Autocombustion Method

Ramesh, S.,Dhanalakshmi, B.,Sekhar, B. Chandra,Rao, P. S. V. Subba,Rao, B. Parvatheeswara,Kim, CheolGi American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.10

<P>Cobalt substituted Ni-Zn ferrite nanoparticles with the formula, Ni0.4Zn0.6-xCoxFe2O4, where x varies from 0.00 to 0.25 in steps of 0.05, were prepared by sol-gel autocombustion method and analyzed for their structural and magnetic properties. The synthesized nanoparticles were subjected to X-ray analysis, transmission electron microscopy, Fourier transform infrared spectroscopy, thermal analysis and magnetic measurements. The X-ray patterns confirm cubic spinel structures with the crystallite sizes in the range from 31.72 nm to 36.87 nm. The particle sizes estimated using electron micrographs are in good agreement with the crystallite sizes obtained from the X-ray data. Infrared data confirms the spinel structure by showing Fe-A-O and Fe-B-O stretching vibrations while the thermal data hints at a slight weight gain due to oxidation. The obtained magnetic data suggests a marginal increase in saturation magnetization with the Co substitution at x = 0.10 and 0.25. The results are analyzed in terms of the compositional and structural modifications, and it was found that the variation of magnetic moment was governed by a corresponding change in the oxygen positional parameter in these materials.</P>