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匹配条件: “Chitra V” ,找到相关结果约130520条。
Extending the Network Lifetime of Wireless Sensor Networks Using Residual Energy Extraction—Hybrid Scheduling Algorithm  [PDF]
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2010, DOI: 10.4236/ijcns.2010.31015
Abstract: Wireless sensor networks (WSNs) are mostly deployed in a remote working environment, since sensor nodes are small in size, cost-efficient, low-power devices, and have limited battery power supply. Because of limited power source, energy consumption has been considered as the most critical factor when designing sensor network protocols. The network lifetime mainly depends on the battery lifetime of the node. The main concern is to increase the lifetime with respect to energy constraints. One way of doing this is by turning off redun-dant nodes to sleep mode to conserve energy while active nodes can provide essential k-coverage, which improves fault-tolerance. Hence, we use scheduling algorithms that turn off redundant nodes after providing the required coverage level k. The scheduling algorithms can be implemented in centralized or localized schemes, which have their own advantages and disadvantages. To exploit the advantages of both schemes, we employ both schemes on the network according to a threshold value. This threshold value is estimated on the performance of WSN based on network lifetime comparison using centralized and localized algorithms. To extend the network lifetime and to extract the useful energy from the network further, we go for compromise in the area covered by nodes.
Wound healing and anti-oxidant activities of the fruit pulp of limonia acidissima linn (rutaceae) in rats
K Ilango, V Chitra
Tropical Journal of Pharmaceutical Research , 2010,
Abstract: Purpose: The fruits of Limonia acidissima Linn are used traditionally in India for the treatment of tumours, asthma, wounds, cardiac debility and hepatitis. The purpose of the present study was to evaluate the wound healing activity of the methanol extract of its fruit pulp (MELA) in incision, excision and dead-space wound models. Methods: Albino rats of either sex were divided into four groups, viz, wounded control, wounded rats administered standard drug, nitrofurazone (2 %), and wounded rats administered MELA 200 and 400 mg/kg, respectively. In incision wound model, wound breaking strength and epithelization period were evaluated, while in excision wound model, wound contraction was studied. In dead-space wound model, granulation tissue dry weight, hydroxyproline levels in dry granulation tissue, as well as superoxide dismutase (SOD) and catalase levels in wet granulation tissue were estimated. Granulation tissue was subjected to histopathological examination in order to determine whether there was healing by formation of collagen in the wound tissue in extract-treated animals. Results: Increased wound breaking strength, decreased epithelization period, increased wound contraction, increased granulation tissue weight and hydroxyproline concentration were observed in the various groups, compared with the control group. Also, increased activity of anti-oxidant enzymes, i.e., higher SOD and catalase levels, were seen in extract-treated groups when compared to controls. Wound healing activity was statistically significant (p < 0.001) in animals treated with 400 mg/kg of the extract. Conclusion: The methanol extract of L. acidissima possesses significant dose-dependant wound healing and anti-oxidant activities; this supports traditional claims for the plant as a wound healer.
Hepatoprotective and antioxidant activities of fruit pulp of limonia acidissima linn
k Ilango, V Chitra
International Journal of Health Research , 2009,
Abstract: Purpose: To investigate the possible hepatoprotective and antioxidant activities of methanolic extract of fruit pulp of Limonia acidissima Linn (MELA) against carbon tetra chloride (CCl4) induced liver damage in rats. Methods: 200 and 400 mg/kg p.o doses of MELA was administered to group of animals for 10 days. Silymarin (100mg/kg) served as a standard and carbon tetrachloride at a dose of 0.5 ml/kg i.p was used to induce liver damage. The various hepatic biochemical parameters like aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total protein (TP), total bilirubin (TB), gamma glutamyl transferase (GGT) and in vivo antioxidant biochemical parameters like super oxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione (GSH) levels were evaluated to determine the hepatoprotective and antioxidant activity. Results: Significant dose dependant hepatoprotective effect of both doses of MELA was observed (p<0.001). The fruit extract significantly restored the antioxidant enzyme level in the liver cells. Conclusion: MELA exhibited significant dose dependant protective effect against CCl4 induced liver damage which can be mainly attributed to the antioxidant property of the extract. This study rationalized the ethno-medicinal use of the plant for curing hepatic injuries.
Variability and association among fruit traits in palmyrah (Borassus flabellifer L.)
V. Ponnuswami* and S. Chitra
Electronic Journal of Plant Breeding , 2011,
Abstract: One hundred and twenty nine palmyrah genotypes were collected from various parts of India and Fruit characterization wasdone.. Variability parameters indicated that high variability exist for fruit weight (g) and weight of shreds (g). Moderatevariability was observed for weight of seed. Low variability was observed for fruit length (cm), fruit diameter (cm), length ofseed (cm), circumference of seed and weight of flesh (g). Hence all the characters except seed weight are good for furtherimprovement through selection. The correlation studies for eight fruit characters indicated that all traits namely fruit weight (g),fruit length (cm), fruit diameter (cm), weight of seed (g), length of seed (cm), circumference of seed, weight of flesh (g) andweight of shreds (g) had significant and positive correlation. Hence simultaneous selection is possible for all these traits inPalmyrah.
Genotypic variation and hierarchical clustering of Palmyrah (Borassus flabellifer L.)
V. Ponnuswami and S. Chitra
Electronic Journal of Plant Breeding , 2011,
Abstract: The genotypic divergence and hierarchical clustering based on morphological, fruit and seed traits was studied in 48 palmyrah genotypes of diverse genetic background. Significant differences were recorded for morphological, fruit and seed characters among genotypes. Highest variability was observed in fruit weight followed by Neera yield and Tree height. Multivariate hierarchical cluster analysis was done to classify genotypes according to their degree of similarity in morphological, fruit seed and pooled traits.
International Journal of Machine Intelligence , 2011,
Abstract: Data authentication and data security are the primary requirement in present day communication system. In image processing, data authentication is implemented using watermarking technique. Recently several watermarking techniques have been proposed. The drawback of these techniques is less robustness, less fidelity and degradation in image quality. Watermarking applications are used in copyright protection, broadcast monitoring, usage control, and this work is implemented for copyright protection using singular value decomposition (SVD) technique. In this technique, the singular values of watermark image are embedded into singular values of host image to get watermarked image. Singular value decomposition (SVD based watermarking techniques is implemented for gray scale and color image of different sizes and the comparative analysis is made based on the results produced when the image is subjected to different types of attacks.
Inhibitory effect of Datura innoxia on the enzymatic activities of the anthracnose fungus Colletotrichum capsici in vitro
Indian Phytopathology , 2012,
Maternal and fetal outcome of dengue fever in pregnancy
T.V. Chitra , Seetha Panicker
Journal of Vector Borne Diseases , 2011,
Abstract: Background & objectives: As adult dengue fever increases it also affects women with pregnancy. Dengue feveris mainly treated conservatively. However, complications like pre-eclampsia, pre-term labour, increased risk ofcaesarean section and fetal transmission have been noted. During dengue epidemic in our region we noted manywomen with dengue fever and observed certain different problems.Methods: A retrospective analysis of all pregnant women admitted in obstetric ward with dengue fever over aperiod of 18 months was done.Results: The striking feature observed was the presence of severe thrombocytopenia in 78.57% of the studypopulation. In addition, coexistence of other vector borne diseases was also noted.Conclusion: Most cases only require conservative treatment. Only women who went into labour required platelettransfusion. Outcome seemed to correlate with gestational age of occurrence of dengue fever
Phase synchronization in an array of driven Josephson junctions
Chitra R. N.,V. C. Kuriakose
Physics , 2008, DOI: 10.1063/1.2889167
Abstract: We consider an array of N Josephson junctions connected in parallel and explore the condition for chaotic synchronization. It is found that the outer junctions can be synchronized while they remain uncorrelated to the inner ones when an external biasing is applied. The stability of the solution is found out for the outer junctions in the synchronization manifold. Symmetry considerations lead to a situation wherein the inner junctions can synchronize for certain values of parameter. In the presence of a phase difference between the applied fields, all the junctions exhibit phase synchronization. It is also found that chaotic motion changes to periodic in the presence of phase differences.
Phase effects on synchronization by dynamical relaying in delay-coupled systems
Chitra R Nayak,V. C. Kuriakose
Physics , 2007,
Abstract: Synchronization in an array of mutually coupled systems with a finite time-delay in coupling is studied using Josephson junction as a model system. The sum of the transverse Lyapunov exponents is evaluated as a function of the parameters by linearizing the equation about the synchronization manifold. The dependence of synchronization on damping parameter, coupling constant and time-delay is studied numerically. The change in the dynamics of the system due to time-delay and phase difference between the applied fields is studied. The case where a small frequency detuning between the applied fields is also discussed.

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