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A Study on the Transmission Dynamics of the Omicron Variant of COVID-19 Using Nonlinear Mathematical Models 被引量:1
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作者 S.Dickson S.Padmasekaran +2 位作者 Pushpendra Kumar Kottakkaran Sooppy Nisar Hamidreza Marasi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2265-2287,共23页
This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected ones.The significant delay... This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected ones.The significant delays eventually resulted in the pandemic’s containment.To ensure the safety of the host population,this concept integrates quarantine and the COVID-19 vaccine.We investigate the stability of the proposed models.The fundamental reproduction number influences stability conditions.According to our findings,asymptomatic cases considerably impact the prevalence of Omicron infection in the community.The real data of the Omicron variant from Chennai,Tamil Nadu,India,is used to validate the outputs. 展开更多
关键词 Omicron local stability reproduction number steady states global stability
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Predictive-Analysis-based Machine Learning Model for Fraud Detection with Boosting Classifiers
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作者 M.Valavan S.Rita 《Computer Systems Science & Engineering》 SCIE EI 2023年第4期231-245,共15页
Fraud detection for credit/debit card,loan defaulters and similar types is achievable with the assistance of Machine Learning(ML)algorithms as they are well capable of learning from previous fraud trends or historical... Fraud detection for credit/debit card,loan defaulters and similar types is achievable with the assistance of Machine Learning(ML)algorithms as they are well capable of learning from previous fraud trends or historical data and spot them in current or future transactions.Fraudulent cases are scant in the comparison of non-fraudulent observations,almost in all the datasets.In such cases detecting fraudulent transaction are quite difficult.The most effective way to prevent loan default is to identify non-performing loans as soon as possible.Machine learning algorithms are coming into sight as adept at handling such data with enough computing influence.In this paper,the rendering of different machine learning algorithms such as Decision Tree,Random Forest,linear regression,and Gradient Boosting method are compared for detection and prediction of fraud cases using loan fraudulent manifestations.Further model accuracy metric have been performed with confusion matrix and calculation of accuracy,precision,recall and F-1 score along with Receiver Operating Characteristic(ROC)curves. 展开更多
关键词 Random forest decision tree logistic regression machine Learning gradient boosting method confusion matrix
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Real-Time Data Transmission with Data Carrier Support Value in Neighbor Strategic Collection in WSN
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作者 S.Ponnarasi T.Rajendran 《Computers, Materials & Continua》 SCIE EI 2023年第6期6039-6057,共19页
An efficient trust-aware secure routing and network strategy-based data collection scheme is presented in this paper to enhance the performance and security of wireless sensor networks during data collection.The metho... An efficient trust-aware secure routing and network strategy-based data collection scheme is presented in this paper to enhance the performance and security of wireless sensor networks during data collection.The method first discovers the routes between the data sensors and the sink node.Several factors are considered for each sensor node along the route,including energy,number of neighbours,previous transmissions,and energy depletion ratio.Considering all these variables,the Sink Reachable Support Measure and the Secure Communication Support Measure,the method evaluates two distinct measures.The method calculates the data carrier support value using these two metrics.A single route is chosen to collect data based on the value of data carrier support.It has contributed to the design of Secure Communication Support(SCS)Estimation.This has been measured according to the strategy of each hop of the route.The suggested method improves the security and efficacy of data collection in wireless sensor networks.The second stage uses the two-fish approach to build a trust model for secure data transfer.A sim-ulation exercise was conducted to evaluate the effectiveness of the suggested framework.Metrics,including PDR,end-to-end latency,and average residual energy,were assessed for the proposed model.The efficiency of the suggested route design serves as evidence for the average residual energy for the proposed framework. 展开更多
关键词 Data carrier support data collection neighbor strategy secure routing wireless sensor network
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Dual antidiabetic and antihypertensive activity of fucoxanthin isolated from Sargassum wightii Greville in in vivo rat model
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作者 Vijayan Raji Chitra Loganathan +1 位作者 Thiyagarajan Ramesh Palvannan Thayumanavan 《Food Science and Human Wellness》 SCIE CSCD 2023年第5期1693-1700,共8页
In a previous study from our laboratory, fucoxanthin purified from brown algae, Sargassum wightii Greville has found to exhibit antioxidant activity and inhibition of angiotensin-I-converting enzyme(ACE)in vitro. The ... In a previous study from our laboratory, fucoxanthin purified from brown algae, Sargassum wightii Greville has found to exhibit antioxidant activity and inhibition of angiotensin-I-converting enzyme(ACE)in vitro. The present study aims in understanding the protective effect of fucoxanthin purified from S. wightii against diabetes with hypertension in in vivo. Diabetes and hypertension were induced in rat by streptozotocin and sodium chloride treatment, respectively. In diabetes with hypertension rat, the blood pressure was increased along with hyperglycemia. Administration of fucoxanthin significantly reduced the blood pressure and ACE activity in diabetes with hypertension rat. Furthermore, administration of fucoxanthin significantly reduced the hyperglycemic state. The activity of various enzymes in the liver(hexokinase, glucose-6-phosphate dehydrogenase, glucose-6-phosphatase and fructose-1,6-phosphatase)and serum(creatine kinase)were normalized to that of control level. The level of glycogen, glycoprotein component and lipid profile were equivalent to control level by fucoxanthin administration in diabetes with hypertension rats. Fucoxanthin ameliorated the oxidative stress by preserving the endogenous antioxidant levels in diabetes with hypertension rats. Also, the pancreatic histological integrity was similar to that of control level in diabetes with hypertension rats by fucoxanthin treatment. Altogether, fucoxanthin showed dual antidiabetic and antihypertensive activity in vivo. 展开更多
关键词 FUCOXANTHIN Diabetes HYPERTENSION Oxidative stress Angiotensin-I-converting enzyme
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Improving QoS Using Mobility-Based Optimized Multipath Routing Protocol in MANET
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作者 S.J.Sangeetha T.Rajendran 《Computer Systems Science & Engineering》 SCIE EI 2023年第7期1169-1181,共13页
Mobile Ad-hoc Networks(MANETs)connect numerous nodes to communicate data from the sender node to the target node.Due to the lack of an infrastructure network,mobile nodes communicate through wireless without an access... Mobile Ad-hoc Networks(MANETs)connect numerous nodes to communicate data from the sender node to the target node.Due to the lack of an infrastructure network,mobile nodes communicate through wireless without an access point.MANET does not have a centralized controller and has a dynamic network topology,which increases link failure and energy consumption resulting in excessive path delay,loss of Quality of service(QoS),and reduced throughput during data communication.Congestion is a significant problem when the QoS of the link carrying the data is degraded.Routing is one of the vital challenges of MANET due to the very dynamic and distributed nature of MANET.This article introduces a Mobility-Based Optimized Multipath Routing Protocol(MBOMRP)and an Efficient Reliable Link-State Transmission(ERLST)algorithm to overcome these problems.The proposed Mobility-Based Optimized Multipath Routing Protocol(MBOMRP)is utilized for route discovery and maintenance to efficiently avoid traffic and sleeping nodes.ERLST algorithm is used for efficient data transmission to increase QoS measurement parameters like throughput,Packet Delivery Ratio(PDR),and minimize the latency performance.The proposed MBOMRP-ERLST algorithm improves data communication network lifetime,avoids link failures,and provides efficient results compared with previous algorithms. 展开更多
关键词 MANET QOS link failure improve data communication avoid traffic network lifetime MBOMRP-ERLST
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Role based access control design using Triadic concept analysis 被引量:7
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作者 Ch.Aswani Kumar S.Chandra Mouliswaran +1 位作者 LI Jin-hai C.Chandrasekar 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第12期3183-3191,共9页
Role based access control is one of the widely used access control models.There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics... Role based access control is one of the widely used access control models.There are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics,and Ontology for representing access control mechanism.However,while using FCA,investigations reported in the literature so far work on the logic that transforms the three dimensional access control matrix into dyadic formal contexts.This transformation is mainly to derive the formal concepts,lattice structure and implications to represent role hierarchy and constraints of RBAC.In this work,we propose a methodology that models RBAC using triadic FCA without transforming the triadic access control matrix into dyadic formal contexts.Our discussion is on two lines of inquiry.We present how triadic FCA can provide a suitable representation of RBAC policy and we demonstrate how this representation follows role hierarchy and constraints of RBAC on sample healthcare network available in the literature. 展开更多
关键词 基于角色的访问控制 三位一体 控制设计 访问控制模型 访问控制机制 RBAC 形式概念分析 网络文献
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Landslide Hazard Zonation Mapping in Ghat Road Section of Kolli Hills, India 被引量:3
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作者 Siddan ANBAZHAGAN Veerappan RAMESH 《Journal of Mountain Science》 SCIE CSCD 2014年第5期1308-1325,共18页
Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation ma... Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation mapping on 1:50,000 scale along ghat road section of Kolli hills using a Landslide Hazard Evaluation Factor(LHEF) rating scheme. The landslide hazard zonation map has been prepared by overlaying the terrain evaluation maps with facet map of the study area. The terrain evaluation maps include lithology, structure, slope morphometry, relative relief, land use and land cover and hydrogeological condition. The LHEF rating scheme and the Total Estimated Hazard(TEHD) were calculated as per the Bureau of Indian Standard(BIS) guidelines(IS: 14496(Part-2) 1998) for the purpose of preparation of Landslide Hazard Zonation(LHZ) map in mountainous terrains. The correction due to triggering factors such as seismicity, rainfall and anthropogenic activities were also incorporated with Total Estimated Hazard to get final corrected TEHD. The landslide hazard zonation map was classified as the high, moderate and low hazard zones along the ghat road section based on corrected TEHD. 展开更多
关键词 山体滑坡 灾害区划 路段 印度 映射 丘陵地形 评价因子 水文地质条件
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Seasonal variations of phytoplankton diversity in the Coleroon coastal waters,southeast coast of India 被引量:3
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作者 Thillai Rajasekar K Rajkumar M +2 位作者 SUN Jun Ashok Prabu V Perumal P 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第5期97-108,共12页
The results of an investigation carried out during June 2005 to May 2007 on physico-chemical parameters,species composition and community structure of phytoplankton including Chlorophyll a(Chl-a) at the Coleroon coa... The results of an investigation carried out during June 2005 to May 2007 on physico-chemical parameters,species composition and community structure of phytoplankton including Chlorophyll a(Chl-a) at the Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(℃) varied from 25.1 to 30.1 and from 24.5 to 28.5 respectively.Salinity values varied from 6 to 28.5 and the pH ranged between 7.0 and 8.3.Variation in dissolved oxygen content was from 3.1 to 7.5 mg/dm^3 while the light extinction coefficient values(LEC) ranged between 3.1 and 10.1 cm.The ranges of inorganic nutrients(μmol/dm^3) viz.,nitrate,nitrite,phosphate and silicate were 10.1-23.4,1.2-8.9,0.2-3.1 and 55-125,respectively.The ranges of Chlorophyll a(μg/dm-3) values was 2.0-7.5.Presently,124 phytoplankton species representing different classes viz:Bacillariophyceae(77),Dinophyceae(19),Cyanophyceae(15),Chlorophyceae(10) and Chrysophyceae(3) were recorded.The phytoplankton cell abundance varied from 0.290 to 111.662 cells/cm-3,with peak diversity(3.38 bits/ind.) during summer season.The maximum abundance was found during summer season coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Canonical Correspondence Analysis(CCA) was applied in this paper for discriminating environmental factors having effect on phytoplankton community at species level.Coleroon coastal water is subjected to long term fluctuations in physico-chemical parameters depending upon the seasonal tidal amplitude and freshwater influx resulting in a continuous exchange of organic,inorganic,plant and animal matters. 展开更多
关键词 physico-chemical parameters PHYTOPLANKTON species composition ABUNDANCE DIVERSITY Coleroon coastal waters
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High resolution facies architecture and digital outcrop modeling of the Sandakan formation sandstone reservoir, Borneo:Implications for reservoir characterization and flow simulation 被引量:3
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作者 Numair A.Siddiqui Mu.Ramkumar +4 位作者 Abdul Hadi A.Rahman Manoj J.Mathew M.Santosh Chow W.Sum David Menier 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第3期957-971,共15页
Advances in photogrammetry have eased the acquisition of high-resolution digital information from outcrops, enabling faster, non-destructive data capturing and improved reservoir modeling. Geocellular models for flow ... Advances in photogrammetry have eased the acquisition of high-resolution digital information from outcrops, enabling faster, non-destructive data capturing and improved reservoir modeling. Geocellular models for flow dynamics with in the virtual outcrop in siliciclastic deposits at different sets of sandstone facies architecture remain, however, a challenge. Digital maps of bedding, lithological contrast, spatial-temporal variations of bedding and permeability characteristics make it more easy to understand flow tortuosity in a particular architecture. An ability to precisely model these properties can improve reservoir characterization and flow modeling at different scales. Here we demonstrate the construction of realistic 2 D sandstone facies based models for a pragmatic simulation of flow dynamics using a combination of digital point clouds dataset acquired from LiDAR and field investigation of the Sandakan Formation, Sabah, Borneo.Additionally, we present methods for enhancing the accuracy of outcrop digital datasets for producing high resolution flow simulation. A well-exposed outcrop from the Sandakan Formation, Sabah, northwest Borneo having a lateral extent of 750 m was chosen in order to implement our research approach. Sandstone facies and its connectivity are well constrained by outcrop observations, data from air-permeability measurements, bilinear interpolation of permeability, grid construction and water vector analysis for flow dynamics.These proportions were then enumerated in terms of static digital outcrop model(DOM) and facies model based on sandstone facies bedding characteristics. Flow simulation of water vector analysis through each of the four sandstone facies types show persistent spatial correlation of permeability that align with either cross-bedded orientation or straight with more dispersion high quality sandstone(porosity 21.25%-41.2%and permeability 1265.20-5986.25 mD) and moderate quality sandstone(porosity 10.44%-28.75% and permeability 21.44-1023.33 mD). Whereas, in more heterolithic sandstone(wavy-to flaser-bedded and bioturbated sandstone), lateral variations in permeability show spatially non-correlated patterns over centimeters to tens of meters with mostly of low quality sandstone(porosity 3.4%-12.31% and permeability < 1 mD to 3.21 mD). These variations reflect the lateral juxtaposition in flow dynamics. It has also been resulted that the vertical connectivity and heterogeneities in terms of flow are mostly pragmatic due to the interconnected sandstone rather than the quality of sandstone. 展开更多
关键词 SILICICLASTIC SANDSTONE FACIES Connectivity HETEROGENEITY DIGITAL outcrop model Flow dynamics
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铬解毒机制诱导香根草的生长和抗氧化反应(英文) 被引量:3
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作者 Manikdanan RAJENDRAN 安文慧 +4 位作者 李伟展 Venkatachalam PERUMAL 吴川 Shivendra Vikram SAHI Santosh Kumar SARKAR 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第2期489-500,共12页
本文研究了铬(Cr)对香根草(Chrysopogon zizanioides)生长以及抗氧化防御酶活性的影响,探讨其对Cr的解毒机制。在50 mg/L Cr处理条件下,植物地上部分和地下部分的生长量分别降低了36.8%和45.0%;Cr在植物地下部分的积累量(9807μg/g干重... 本文研究了铬(Cr)对香根草(Chrysopogon zizanioides)生长以及抗氧化防御酶活性的影响,探讨其对Cr的解毒机制。在50 mg/L Cr处理条件下,植物地上部分和地下部分的生长量分别降低了36.8%和45.0%;Cr在植物地下部分的积累量(9807μg/g干重)大于地上部分的积累量(8730μg/g干重)。随着Cr添加量的增加,光合色素和丙二醛含量增加,在30 mg/L Cr处理条件下含量达到最高,之后,随着Cr处理浓度的增加略有下降;同时,抗氧化防御酶(超氧化物歧化酶、过氧化氢酶和过氧化物酶)的活性显著提高,在较高浓度Cr处理下略有下降。同工酶结果显示在高浓度Cr处理下,超氧化物歧化酶、过氧化氢酶和过氧化物酶的条带强度降低。目前研究结果表明,高浓度Cr导致活性氧过量产生,从而增加了对香根草的氧化损伤,而光合色素、丙二醛、抗氧化酶含量的增加表明香根草对Cr有潜在的耐性机制。结果表明,香根草具有对Cr的解毒机制,并可以积累高浓度的Cr。本文为更深入地研究根草对Cr的解毒机制提供了依据。 展开更多
关键词 Chrysopogon zizanioides 解毒机制 抗氧化酶 植物修复
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Antioxidant and hepatoprotective effects of Hypsizygus ulmarius polysaccharide on alcoholic liver injury in rats 被引量:6
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作者 Sudha Govindan Angu Jayabal +1 位作者 Jayasakthi Shanmugam Prasanna Ramani 《Food Science and Human Wellness》 SCIE 2021年第4期523-535,共13页
Hypsizygus ulmarius polysaccharide(HUP)is a water-soluble polysaccharide obtained by hot water extraction,followed by precipitation and deproteinization.The characteristics of HUP,antioxidant activity and liver protec... Hypsizygus ulmarius polysaccharide(HUP)is a water-soluble polysaccharide obtained by hot water extraction,followed by precipitation and deproteinization.The characteristics of HUP,antioxidant activity and liver protection against alcohol-induced liver damage were studied.Structural characteristics indicate that the HUP is a pyran-type polysaccharide with a molecular weight of 2076 Da.In antioxidant scavenging assay,HUP showed moderate DMPD radical scavenging activity,cupric ion reducing antioxidant capacity and inhibitory effect against lipid peroxidation in a dose-dependent manner.Regarding in vivo hepatoprotective activity,compared with the ethanol induction group,pre-treatment of low and high doses of HUP signifi cantly reduced the behaviours of serum enzymes,lowered the levels of hepatic oxidative stress markers,restored the levels of biochemical constituents,enhanced the levels of liver and serum enzymatic antioxidants and non-enzymatic antioxidants,and improved the serum lipid levels of alcohol-intoxicated rats.The hepatoprotective effect of HUP was comparable to positive control silymarin.Besides,HUP pre-treatment signifi cantly normalized the histopathological changes induced by ethanol.The results indicate that HUP could be used as a functional food and may protect the biological system from oxidative stress through its antioxidant activity,thus having a signifi cant protective effect on acute alcoholic liver injury. 展开更多
关键词 Hypsizygus ulmarius polysaccharide Antioxidant activity Hepatoprotective behaviour Ethanol consumption Liver damage
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High Ba-Sr adakitic charnockite suite from the Nagercoil Block,southern India:Vestiges of Paleoproterozoic arc and implications for Columbia to Gondwana 被引量:2
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作者 Pin Gao M.Santosh +2 位作者 Cheng-Xue Yang Sanghoon Kwon Mu.Ramkumar 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第3期577-596,共20页
The Nagercoil block is the southernmost crustal segment of the Southern Granulite Terrane(SGT)in India and is mainly composed of charnockitic rocks and felsic gneisses(charnockite suite).In this study,we present petro... The Nagercoil block is the southernmost crustal segment of the Southern Granulite Terrane(SGT)in India and is mainly composed of charnockitic rocks and felsic gneisses(charnockite suite).In this study,we present petrologic,geochemical,zircon U-Pb,REE,and Hf isotopic studies on the charnockites and leucogneiss from the Nagercoil block.Based on field investigations and petrologic studies,the charnockites can be divided into garnet-bearing and garnet-absent anhydrous granulite facies rocks with orthopyroxene.The charnockites and leucogneiss show transition from adakites to non-adakitic magmatic rocks,with enrichment in LREEs(light rare earth elements)and LILEs(large ion lithophile elements),and depletion in HREEs(heavy rare earth elements)and HFSEs(high field strength elements).Some of the charnockites and the leucogneiss show typical HSA(high silica adakite)characters,(high SiO_(2),Al_(2)O_(3),Ba-Sr,La/Yb,and Sr/Y).The HSA is considered to have formed from the interaction of slab derived melts and peridotitic mantle wedge.The high Ba-Sr features were possibly inherited from subducted oceanic crust melting under high thermal gradient during Precambrian.The magmas were underplated and subjected to fractional crystallization.Zircon grains from the charnockite and leucogneiss show zoned magmatic cores surrounded by structureless metamorphic rims.Magmatic zircon grains from the charnockites show ages ranging from 1983±8.8 Ma to 2046±14 Ma,and the metamorphic domains show an age range of 502±14 Ma to 547±8.7 Ma.Zircon from the leucogneiss yielded magmatic and metamorphic ages of 1860±20 Ma and 575.6±8.8 Ma.Both charnockites and leucogneiss show two prominent age peaks at 1987 Ma and 568 Ma.The REE data of the zircon grains show LREE depletion and HREE enrichment,with the metamorphic grains showing more depletion in HREE.Zircon Hf isotopic data of the magmatic cores of zircon grains from the charnockite yieldedε_(Hf)(t)values from-1.17 to 0.46 with T_(DM)and T_(DM)~C and age peaks at 2392 Ma and 2638 Ma,suggesting Neoarchean to Paleoproterozoic juvenile sources.We suggest that the high Ba-Sr adakitic charnockite suite from the Nagercoil block formed in a Paleoproterozoic magmatic arc setting during the assembly of the Columbia supercontinent,and underwent high-grade metamorphism associated with the amalgamation of the Gondwana supercontinent during the late Neoproterozoic-Cambrian.Our study provides new insights into the vestiges of Columbia fragments within the Gondwana assembly with two distinct cycles of crustal evolution. 展开更多
关键词 CHARNOCKITE Adakitic rocks High Ba-Sr granitoids Geochemistry and zircon geochronology Nagercoil block Columbia and Gondwana supercontinents
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用棉籽壳制备的碳纤维去除饮用水中的氟化物:动力学评价(英文) 被引量:1
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作者 Rajan Mariappan Raj Vairamuthu Alagumuthu Ganapathy 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第4期710-721,共12页
Chemically activated cotton nut shell carbons(CTNSCs)were prepared by different chemicals and they were used for the removal of fluoride from aqueous solution.Effects of adsorption time,adsorbent dose,p H of the solut... Chemically activated cotton nut shell carbons(CTNSCs)were prepared by different chemicals and they were used for the removal of fluoride from aqueous solution.Effects of adsorption time,adsorbent dose,p H of the solution,initial concentration of fluoride,and temperature of the solution were studied with equilibrium,thermodynamics and kinetics of the adsorption process by various CTNSC adsorbents.It showed that the chemically activated CTNSCs can effectively remove fluoride from the solution.The adsorption equilibrium data correlate well with the Freundlich isotherm model.The adsorption of fluoride by the chemically activated CTNSC is spontaneous and endothermic in nature.The pseudo first order,pseudo second order and intra particle diffusion kinetic models were applied to test the experimental data.The pseudo second order kinetic model provided a better correlation of the experimental data in comparison with the pseudo-first-order and intra particle diffusion models.A mechanism of fluoride adsorption associating chemisorption and physisorption processes is presented allowing the discussion of the variations in adsorption behavior between these materials in terms of specific surface area and porosity.These data suggest that chemically activated CTNSCs are promising materials for fluoride sorption. 展开更多
关键词 氟化物污染 动力学模型 化学活化 FREUNDLICH方程 果壳 棉花 饮用水 吸附时间
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Improved Rough Set Algorithms for Optimal Attribute Reduct 被引量:1
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作者 C.Velayutham K.Thangavel 《Journal of Electronic Science and Technology》 CAS 2011年第2期108-117,共10页
Feature selection(FS) aims to determine a minimal feature(attribute) subset from a problem domain while retaining a suitably high accuracy in representing the original features. Rough set theory(RST) has been us... Feature selection(FS) aims to determine a minimal feature(attribute) subset from a problem domain while retaining a suitably high accuracy in representing the original features. Rough set theory(RST) has been used as such a tool with much success. RST enables the discovery of data dependencies and the reduction of the number of attributes contained in a dataset using the data alone,requiring no additional information. This paper describes the fundamental ideas behind RST-based approaches,reviews related FS methods built on these ideas,and analyses more frequently used RST-based traditional FS algorithms such as Quickreduct algorithm,entropy based reduct algorithm,and relative reduct algorithm. It is found that some of the drawbacks in the existing algorithms and our proposed improved algorithms can overcome these drawbacks. The experimental analyses have been carried out in order to achieve the efficiency of the proposed algorithms. 展开更多
关键词 Data mining entropy based reduct Quickreduct relative reduct rough set selection of attributes
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Hierarchical delineation and multivariate statistical discrimination of chemozones of the Cauvery Basin,south India:Implications on spatio-temporal scales of stratigraphic correlation 被引量:1
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作者 RAMKUMAR Mu. BERNER Z. STBEN D. 《Petroleum Science》 SCIE CAS CSCD 2010年第4期435-447,共13页
Success in locating oil pools in the Cauvery Basin,south India had been found to be based on the ability to delineate precisely the stratigraphic traps resulting from frequent sea level changes.However,recognition and... Success in locating oil pools in the Cauvery Basin,south India had been found to be based on the ability to delineate precisely the stratigraphic traps resulting from frequent sea level changes.However,recognition and delineation of them in terms of depositional units through conventional stratigraphic methods have been elusive owing to the limitations of such methods and lack of unified stratigraphic markers that could be traced at regional and basinal scale.This paper attempts to recognize depositional units in terms of chemozones,chronologic and lithostratigraphic units by assigning distinct geochemical signatures.Geochemical signatures were assigned through hierarchical delineation and discriminant function analysis.It is observed that individual depositional units could be recognized statistically with whole-rock geochemical composition.The strata under study show two second order chemozones comprising six major chemozones that in turn correspond to third order sea level cycles and minor chemozones at the scale of fourth order and/or further shorter sea level cycles.The geochemical signatures showed 100% distinctness between sample populations categorized according to chronostratigraphy and lithostratigraphy.The durations of these stratigraphic units range from 18 million years to less than a million years and indicate distinct geochemical compositional change at different time slices.By implication and also due to the close correspondence between sea level variations reported from this basin and global sea level cycles,it is suggested that recognition and correlation of individual depositional units with distal counterparts could be made accurately.Implication of these results is that stratigraphic units,at varying scales either temporally or spatially,could be assigned with unique geochemical signature,with which accurate prediction and correlation of similar units elsewhere is possible with measurable accuracy. 展开更多
关键词 CHEMOSTRATIGRAPHY statistical discrimination petroleum exploration stratigraphic correlation
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Bloom Forming Species of Phytoplankton in Two Coastal Waters in the Southeast Coast of India 被引量:1
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作者 K. Thillai Rajasekar M. Rajkumar +2 位作者 SUN Jun V. Ashok Prabu E Perumal 《Journal of Ocean University of China》 SCIE CAS 2010年第3期265-272,共8页
The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters(Southeast coast of India) are ... The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(℃) varied from 25.1 to 30.1 and 24.5 to 28.5,respectively,in the former waters and from 25.5 to 31.2 and 25.0 to 29.3 in the latter waters.The respective salinities varied from 6.0 to 28.5 and 5.0 to 33.1 and the respective pH ranged between 7.0 and 8.3 and 7.2 and 8.3.Correspondingly,the dissolved oxygen content varied from 3.1 to 7.5 and 3.1 to 7.9 mgL-1 while the light extinction coefficient(LEC) values ranged between 3.1 and 10.1 and 1.8 and 11.0.The content ranges of inorganic nutrients,i.e.,nitrate,nitrite,phosphate and silicate(μmolL-1),in the Parangipettai and Coleroon coastal waters were:6.5-27.0;1.0-8.9;0.1-3.0 and 15.0-140 and 10.1-23.4;1.2-8.9;0.2-3.1 and 55-125 respectively.The chlorophyll a contents in both waters ranged from 2.0-7.5 μgL-1.Presently,124 phytoplankton species representing different classes were recorded in the Coleroon coast,viz,Bacillariophyceae(77);Dinophyceae(19);Cyanophyceae(15);Chlorophyceae(10) and Chrysophyceae(3),whereas 117 phytoplankton species were recorded in the Parangipettai coast,viz,Bacillariophyceae(66);Dinophyceae(22);Cyanophyceae(19);Chlorophyceae(7) and Chrysophyceae(3).The phytoplankton cell abundance in the Parangipettai and Coleroon coastal waters varied from 290 to 111662 and 140 to 132 757 cells L-1,respectively,with peak diversity(3.38 and 3.52 bits ind-1.) recorded in summer.The maximum abundance occurred in summer coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Totally 31 and 24 species of phytoplankton were found to be bloom-forming in the Parangipettai and Coleroon coastal waters,respectively.Presently Trichodesmium bloom was also observed,which appeared at the 10 fathom level of the coastal water and quickly spread to the marine zone of the Vellar estuary and near the mouth region of the mangrove waters.The Parangipettai and Coleroon coastal waters are subject to long term fluctuations in physico-chemical conditions depending upon the seasonal tidal range and freshwater influx,resulting in a continuous exchange of organic,inorganic,plant and animal matters. 展开更多
关键词 沿海水域 植物种类 东南沿海 印度 晶状体上皮细胞 浮游植物 物理化学条件 亚硝酸盐
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Rice Husk Templated Mesoporous ZnO Nanostructures for Ethanol Sensing at Room Temperature 被引量:2
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作者 M. Chitra K. Uthayarani +3 位作者 N. Raj asekaran N. Neelakandeswari E. K. Girija D. Pathinettam Padiyan 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第7期202-205,共4页
Mesoporous zinc oxide nanostructures are successfully synthesized via the sol-gel route by using a rice husk as the template for ethanol sensing at room temperature. The structure and morphology of the nanostructures ... Mesoporous zinc oxide nanostructures are successfully synthesized via the sol-gel route by using a rice husk as the template for ethanol sensing at room temperature. The structure and morphology of the nanostructures are characterized by x-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and nitrogen adsorption-desorption analyses. The mechanism for the growth of zinc oxide nanostructures over the biotemplate is proposed. SEM and TEM observations also reveal the formation of spherical zinc oxide nanoparticles over the interwoven fibrous network. Multiple sized pores having pore diameter ranging from 10- 4Ohm is also evidenced from the pore size distribution plot. The larger surface area and porous nature of the material lead to high sensitivity (40.93% for 300 ppm of ethanol), quick response (42s) and recovery (40 s) towards ethanol at 30014. The porous nature of the interwoven fibre-like network affords mass transportation of ethanol vapor, which results in faster surface accessibility, and hence it acts as a potential candidate for ethanol sensing at room temperature. 展开更多
关键词 ZNO Rice Husk Templated Mesoporous ZnO Nanostructures for Ethanol Sensing at Room Temperature
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Propagation of an electromagnetic soliton in an anisotropic biquadratic ferromagnetic medium 被引量:2
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作者 L.Kavitha M.Saravanan D.Gopi 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期275-281,共7页
Information storage technology based on anisotropic ferromagnets with sufficiently high magneto-optical effects has received much attention in recent years.Magneto-optical recording combines the merits of magnetic and... Information storage technology based on anisotropic ferromagnets with sufficiently high magneto-optical effects has received much attention in recent years.Magneto-optical recording combines the merits of magnetic and optical techniques.We investigate the magneto-optical effects on a biquadratic ferromagnet and show that the dynamics of the system are governed by a perturbed nonlinear Schro¨dinger equation.The evolutions of amplitude and velocity of the soliton are found to be time independent,thereby admitting the lossless propagation of the electromagnetic soliton in the medium,which may have potential applications in soliton based optical communication systems.We also exploit the role of perturbation,which has a significant impact on the propagation of an electromagnetic soliton. 展开更多
关键词 solitons classical spin models Maxwell equations nonlinear dynamics
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Mapping of hard rock aquifer system and artificial recharge zonation through remote sensing and GIS approach in parts of Perambalur District of Tamil Nadu, India 被引量:1
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作者 A Muthamilselvan N Rajasekaran R Suresh 《Journal of Groundwater Science and Engineering》 2019年第3期264-281,共18页
Mapping of hard rock aquifer system and artificial recharge zonation were carried out in an area of 325 km^2 in parts of the Perambalur District,Tamil Nadu,India.This district has been declared as one of the over-expl... Mapping of hard rock aquifer system and artificial recharge zonation were carried out in an area of 325 km^2 in parts of the Perambalur District,Tamil Nadu,India.This district has been declared as one of the over-exploited regions in Tamil Nadu by the Central Groundwater Board.To raise the groundwater level,suitable recharge zones were identified and artificial recharge structures are suggested using geomatics technology in the present study.To this end,various thematic maps concerning lithology,soil,geomorphology,land use,land cover,slope,lineament,lineament density,drainage,drainage density and groundwater depth level were prepared.Fissile hornblende gneiss(244 km^2)covered most of the study area followed by charnockites(68 km^2).Structural hills and rocky pediments characterize the major geomorphological features in the targeted area,and are followed by deep moderated pediments.The area is mostly used as crop and fallow land,followed by scrub land and deciduous forest.In the study area,the slopes are predominantly very gentle(142 km^2)and nearly level(66 km^2)ones.Besides,Groundwater level data of 58 wells have been generated,in which the minimum and maximum depth were 3 and 28 m respectively.Integration under the GIS environment has been carried out using all the thematic layers to identify the groundwater prospect zone through the introduction of weight and rank methods.Integrated output performances were classified into very poor,poor,moderate,good and excellent categories.All these classes were further divided into two groups as suitable and non-suitable area for the selection of recharge sites.Hard rock fractures were mapped as lineaments from satellite images,and besides that,rose diagram was also generated to find out the trend of the fracture.Furthermore,fracture data of 146 numbers have been collected using Brunton compass to generate rose diagram and were correlated with the rose diagram derived from lineaments.The present study significantly brought up a few areas such as Ammapalayam,Melapuliyur,Senjeri and around Siruvachur for artificial recharge. 展开更多
关键词 HARD rock AQUIFER Artificial RECHARGE Remote sensing and GIS GROUNDWATER level
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Evaluation of eco-friendly coagulant from <i>Trigonella foenum-graecum</i>seed 被引量:1
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作者 Chitteti Ramamurthy Malige Uma Maheswari +3 位作者 Natarajan Selvaganabathy Muthuvel Suresh Kumar Venugopal Sujatha Chinnasamy Thirunavukkarasu 《Advances in Biological Chemistry》 2012年第1期58-63,共6页
The ability of seed extracts of Trigonella foenum-graecum (T. foenum-graecum) and Cuminum cyminum (C. cyminum) to act as natural coagulants was tested using natural turbid water. Seed extracts were prepared using dist... The ability of seed extracts of Trigonella foenum-graecum (T. foenum-graecum) and Cuminum cyminum (C. cyminum) to act as natural coagulants was tested using natural turbid water. Seed extracts were prepared using distilled water and NaCl (0.5 M and 1.0 M) solution. Only 1.0 M NaCl extract of T. foenum-graecum had coagulation capability and did not depend on pH values. Further it showed that natural coagulant obtained from T. foenum-graecum is temperature (upto 100?C) and pH stable (pH 4.0 - 10.0). Extract of C. cyminum had very minimal (16 ± 2) coagulation property. The seed extract of T. foenum-graecum showed about 80% coagulation properties, where as the best known natural coagulants such as Strychnos potatorum and Moringa oleifera, and chemical coagulant such as Al2(SO4)3 showed around 90%, 65% and 95% respectively, which are used as standards for the present study. When compared with pond water, T. foenum-graecum extract treated water shows decrease in alkalinity, turbidity, KMnO4 demand and total coli-form. This study reveals that seed extract of T. foenum-graecum can be used as natural water coagulant. 展开更多
关键词 Natural COAGULANTS Water PURIFIER T. foenum-graecum FENUGREEK
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