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An enhanced cosine-based visual technique for the robust tweets data clustering

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International Journal of Intelligent Computing and Cybernetics 2021年第2期14卷 170-184页

作者： Narasimhulu K. Meena Abarna K.T. sivakumar B. Annamalai University ChidambaramIndiaand Rajeev Gandhi Memorial College of Engineering and Technology NandyalIndia

Purpose-The purpose of the paper is to study multiple viewpoints which are required to access the more informative similarity features among the tweets documents,which is useful for achieving the robust tweets data clustering ***/methodology/approach-Let“N”be the number of tweets documents for the topics *** texts,punctuations and other symbols are removed,tokenization and stemming operations are performed in the initial tweets pre-processing ***-of-features are determined for the tweets;later tweets are modelled with the obtained bag-of-features during the process of topics *** of topics features are extracted for every tweet *** set of topics features of N documents are treated as *** key idea of the proposed work is to use multi-viewpoints in the similarity features *** following figure illustrates multi-viewpoints based cosine similarity computation of the five tweets documents(here N 55)and corresponding documents are defined in projected space with five viewpoints,say,v_(1),v_(2),v_(3),v4,and *** example,similarity features between two documents(viewpoints v_(1),and v_(2))are computed concerning the other three multi-viewpoints(v_(3),v4,and v5),unlike a single viewpoint in traditional cosine ***-Healthcare problems with tweets *** models play a crucial role in the classification of health-related tweets with finding topics(or health clusters)instead of finding term frequency and inverse document frequency(TF-IDF)for unlabelled ***/value-Topic models play a crucial role in the classification of health-related tweets with finding topics(or health clusters)instead of finding TF-IDF for unlabelled tweets.

关键词： Tweets data clustering Topic models TF-IDF Similarity features Visual technique VAT cVAT MVCS-VAT

TbF3 nanoparticles as dual-mode contrast agents for ultrahigh field magnetic resonance imaging and X-ray computed tomography

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Nano Research 2016年第4期9卷 1135-1147页

作者： Xiaoyu Zheng Yanjie Wang Lingdong Sun Naixiu Chen Lindong Li Shuo Shi sivakumar Malaisamy Chunhua Yan Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and Applications PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry College of Chemistry and Molecular Engineering Peking University Beijing 10087 I China

Considering the development of magnetic resonance imaging （MRI） under ultrahigh magnetic field （〉3 T）, the exploration of novel contrast agents （CAs） for ultrahigh field MRI is urgently needed. Herein, we report polyethyleneimine （PEI）-coated TbF3 nanoparticles （NPs）, which were synthesized by a facile solvothermal method, as potential dual-mode CAs for ultrahigh field MRI and X-ray computed tomography （CT）. Owing to their strong paramagnetism, the TbF3 NPs showed excellent transverse relaxivity （395.77 mM-l.s-1） and negligible longitudinal relaxivity under an ultrahigh magnetic field （7 T） with a great potential as a T2-weighted MRI contrast agent. Furthermore, by comparison with the clinically used CT CAs （iohexol）, the TbF3 NPs showed superior X-ray attenuation ability. The practical application for T2-weighted MRI and CT imaging was demonstrated with an animal model. Moreover, cell cytotoxicity and in vivo toxicity assessments implied the low toxicity of TbF3 NPs. In summary the above results indicate that TbF3 NPs are promising candidates for ultrahigh field MRI and CT dual-mode imaging.

关键词： nanoparticle TbF3,magnetic resonance imaging (MRI),computed tomography(CT),contrast agent

Combustion performance of hybrid rocket fuels loaded with MgB_(2)and carbon black additives

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Propulsion and Power Research 2023年第2期12卷 212-226页

作者： Yash Pal Sasi Kiran Palateerdham Sri Nithya Mahottamananda Subha sivakumar Antonella Ingenito School of Aeronautical Sciences Hindustan Institute of Technology and ScienceChennai 603103India School of Aerospace Engineering University of Rome“La Sapienza”00138RomeItaly Department of Aerospace Engineering BS Abdur Rahman Crescent Institute of Science&TechnologyChennai 600048India

Paraffin-based fuel has a great potential for several innovative missions,including space tourism,due to its safety,low environmental impact,high performance and low *** the fact that liquefying solid fuels increases the regression rate of hybrid rocket motors,incorporating energetic materials into solid fuel can still improve the *** objective and scope of this study is to increase the performance characteristics of the paraffin-based fuel by using magnesium diboride(MgB_(2))and carbon black(CB)*** cylindricalport fuel grains were manufactured with various additives percentages in mass(wt%:CB-2%and MgB_(2)-10%)and tested using a laboratory-scale ballistic hybrid motor under gaseous *** mechanical performance results revealed that adding CB and MgB_(2) improved the ultimate strength and elastic modulus of paraffin-based *** addition of these fillers increased the hardness of fuel by developing a strong interaction in the paraffin ***(TG)results showed that CB inclusion improved the thermal stability of the paraffin *** average regression rates of fuels loaded with CB and MgB_(2) were 32%and 52%higher than those of unmodified paraffin wax,*** characteristic velocity efficiency was found in the range of 68%e79%at an O/F ratio of *** MgB_(2) oxidation/combustion in the paraffin matrix was described by a four-step oxidation process ranging from 473 K to 1723 ***,a combustion model of MgB_(2) in the paraffin matrix was proposed,and four-step oxidation processes were discussed in detail.

关键词： Hybrid rocket Paraffin wax Regression rate Magnesium diboride Mechanical properties

Can the Grain-for-Green Program Really Ensure a Low Sediment Load on the Chinese Loess Plateau?

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Engineering 2019年第5期5卷 855-864页

作者： Pengcheng Sun Yiping Wu Zhifeng Yang Bellie sivakumar Linjing Qiu Shuguang Liu Yanpeng Cai Department of Earth and Environmental Science School of Human Settlements and Civil EngineeringXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China School of Civil and Environmental Engineering The University of New South WalesSydneyNSW 2052Australia Department of Land Air and Water ResourcesUniversity of CaliforniaDavisCA 95616USA Department of Civil Engineering Indian Institute of Technology BombayMumbai 400076India National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China Central South University of Forestry and TechnologyChangsha 410004China

The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow *** the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment ***,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess *** investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this *** results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological *** increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large *** finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.

关键词： Discharge–sediment relationship Ecological restoration Loess hilly region Sediment load Sediment rating parameters

MIoT Based Skin Cancer Detection Using Bregman Recurrent Deep Learning

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Computers, Materials & Continua 2022年第12期73卷 6253-6267页

作者： Nithya Rekha sivakumar Sara Abdelwahab Ghorashi Faten Khalid Karim Eatedal Alabdulkreem Amal Al-Rasheed Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11671Saudi Arabia Department of Information Systems College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11671Saudi Arabia

Mobile clouds are the most common medium for aggregating,storing,and analyzing data from the medical Internet of Things(MIoT).It is employed to monitor a patient’s essential health signs for earlier disease diagnosis and *** the various disease,skin cancer was the wide variety of cancer,as well as enhances the endurance *** recent years,many skin cancer classification systems using machine and deep learning models have been developed for classifying skin tumors,including malignant melanoma(MM)and other skin ***,accurate cancer detection was not performed with minimum time *** order to address these existing problems,a novel Multidimensional Bregman Divergencive Feature Scaling Based Cophenetic Piecewise Regression Recurrent Deep Learning Classification(MBDFS-CPRRDLC)technique is introduced for detecting cancer at an earlier *** MBDFS-CPRRDLC performs skin cancer detection using different layers such as input,hidden,and output for feature selection and *** patient information is composed of *** patient information was stored in mobile clouds server for performing predictive *** collected data are sent to the recurrent deep learning *** the first hidden layer,the feature selection process is carried out using the Multidimensional Bregman Divergencive Feature Scaling technique to find the significant features for disease identification resulting in decreases time *** by,the disease classification is carried out in the second hidden layer using cophenetic correlative piecewise regression for analyzing the testing and training *** process is repeatedly performed until the error gets *** this way,disease classification is accurately performed with higher *** evaluation is carried out for factors namely Accuracy,precision,recall,F-measure,as well as cancer detection time,by the amount of patient *** observed result confirms that the pr

关键词： MIoT skin cancer detection recurrent deep learning classification multidimensional bregman divergencive scaling cophenetic correlative piecewise regression

EfficientNetV2 Model for Plant Disease Classification and Pest Recognition

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Computer Systems Science & Engineering 2023年第5期45卷 2249-2263页

作者： R.S.Sandhya Devi V.RVijay Kumar P.sivakumar Department of EEE Kumaraguru College of TechnologyCoimbatore641049India Department of Electronics and Communication Engineering Anna University Regional CampusCoimbatore641046India Department of EEE PSG College of TechnologyCoimbatore641004India

Plant disease classification and prevention of spreading of the disease at earlier stages based on visual leaves symptoms and Pest recognition through deep learning-based image classification is in the forefront of *** perform the investigation on Plant and pest classification,Transfer Learning(TL)approach is used on *** requires limited labelled data and shorter training ***,the limitation of TL is the pre-trained model network’s topology is static and the knowledge acquired is detrimentally overwriting the old ***-V2 is a Convolutional Neural Network(CNN)model with significant high speed learning rates across variable sized *** model employs a form of progressive learning mechanism which expands the network topology gradually over the course of training process improving the model’s learning *** provides a better interpretability of the model’s understanding on the test *** these insights,our work investigates the effectiveness of EfficienetV2 model trained on a class imbalanced dataset for plant disease classification and pest recognition by means of combining TL and progressive learning *** Progressive Learning for TL(PL-TL)is used in our work consisting of 38 classes of PlantVillage dataset of crops and fruit species,5 classes of cassava leaf diseases and another dataset with around 102 classes of crop pest images downloaded from popular dataset platforms,though it is not a benchmark *** test the predictability rate of the model in classifying leaf diseases with similar visual symptoms,Mix-up data augmentation technique is used at the ratio of 1:4 on corn and tomato classes which has high probability of misinterpretation of disease ***,the paper compares the TL approach performed on the above mentioned three types of data set using well established CNN based Inceptionv3,and Vision Transformer a non-CNN *** clearly depicts that EfficientNetV2 has an out

关键词： Image classification transfer learning efficientNetV2 mix-up data augmentation inception V3

Modelling and Coordinated Control of Grid Connected Photovoltaic,Wind Turbine Driven PMSG,and Energy Storage Device for a Hybrid DC/AC Microgrid

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Protection and Control of Modern Power Systems 2023年第1期8卷 180-193页

作者： Prabhakaran Koothu Kesavan Umashankar Subramaniam Dhafer Jaber Almakhles sivakumar Selvam Renewable Energy Laboratory the Department of Electrical EngineeringPrince Sultan UniversityRiyadh11586Saudi Arabia 不详

In a DC/AC microgrid system,the issues of DC bus voltage regulation and power sharing have been the subject of a significant amount of ***-tion of renewable energy into the grid involves multiple converters and these are vulnerable to perturbations caused by transient *** enhance the flexibility and controllability of the grid connected converter(GCC),this paper proposes a common DC bus voltage maintenance and power sharing control strategy of a GCC for a DC/AC microgrid.A maximum power point tracking algorithm is employed to enhance the power delivered by the wind turbine and photovoltaic *** proposed control strategy consists of primary and secondary *** the primary layer control,the DC bus voltage is regulated by the *** the secondary layer,the DC bus voltage is maintained by the energy storage *** ensures reliable power for local loads during grid failures,while power injection to the grid is controlled by an en-ergy management algorithm followed by reference gen-eration of inductor current in the *** proposed control strategy operates in different modes of DC voltage regulation,power injection to the grid and a hybrid op-erating *** provides wide flexible control and en-sures the reliable operation of the *** pro-posed and conventional techniques are compared for a 15.8 kW DC/AC microgrid system using the MATLAB/Simulink *** simulation results demonstrate the transient behaviour of the system in different operating *** proposed control technique is twice as fast in its transient response and produces less oscillation than the conventional *** Terms—Wind energy,photovoltaic energy,DC/AC microgrid,battery energy storage system,co-ordinated control.

关键词： Wind energy photovoltaic energy DC/AC microgrid battery energy storage system co-ordinated control

Statistical optimization and anticancer activity of a red pigment isolated from Streptomyces sp. PM4

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Asian Pacific Journal of Tropical Biomedicine 2013年第8期3卷 650-656页

作者： Valliappan Karuppiah Chandramohan Aarthi Kannan sivakumar Lakshmanan Kannan CAS in Marine Biology Faculty of Marine SciencesAnnamalai UniversityParangipettai 608502Tamil NaduIndia Marine Biotechnology Laboratory State Key Laboratory of Microbial Metabolism and School of Life Sciences and BiotechnologyShanghai Jiao TongUniversityShanghai 200240P.R. China

Objective:To enhance the pigment production ***4 for evaluating its anticancer ***:Response surface methodology was employed to enhance the production of red pigment *** pigment was purified and evaluated for the anticancer activity against HT1080,Hep2,HeLa and MCF7 cell lines by MTT ***:Based on the response surface methodology,it could be concluded that maltose (4.06 g),peptone (7.34 g),yeast extract(4.34 g)and tyrosine(2.89 g)were required for the maximum production of pigment(1.68 g/L)by *** of the medium with the above tested features increased the pigment yield by 4.6 *** showed the potential anticancer activity against HT1080,HEp-2,HeLa and MCF-7cell lines with the IC50value of 18.5,15.3,9.6 and 8.5 ***:The study revealed that the maximum amount of pigment could be produced to treat cancer.

关键词： Streptomyces Pigment Response surface methodology Anticancer activity

Experimental investigation and ANN modeling on improved performance of an innovative method of using heave response of a non-floating object for ocean wave energy conversion

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Frontiers in Energy 2013年第3期7卷 279-287页

作者： Srinivasan CHANDRASEKARAN Arunachalam AMARKARTHIK Karuppan sivakumar Dhanasekaran SELVAMUTHUKUMARAN Shaji SIDNEY Department of Ocean Engineering Indian Institute of TechnologyMadras Chennai 600036 India Department of Mechanical Engineering Bannari Amman Institute ofTechnology TamilNadu 638401 India

To convert wave energy into usable forms of energy by utilizing heaving body, heaving bodies （buoys） which are buoyant in nature and float on the water surface are usually used. The wave exerts excess buoyancy force on the buoy, lifting it during the approach of wave crest while the gravity pulls it down during the wave trough. A hydraulic, direct or mechanical power takeoff is used to convert this up and down motion of the buoy to produce usable forms of energy. Though using a floating buoy for harnessing wave energy is conventional, this device faces many challenges in improving the overall conversion efficiency and survivability in extreme conditions. Up to the present, no studies have been done to harness ocean waves using a non-floating object and to find out the merits and demerits of the system. In the present paper, an innovative heaving body type of wave energy converter with a non-floating object was proposed to harness waves. It was also shown that the conversion efficiency and safety of the proposed device were significantly higher than any other device proposed with floating buoy. To demonstrate the improvements, experiments were conducted with non- floating body for different dimensions and the heave response was noted. Power generation was not considered in the experiment to observe the worst case response of the heaving body. The device was modeled in artificial neural network （ANN）, the heave response for various parameters were predicted, and compared with the experimental results. It was found that the ANN model could predict the heave response with an accuracy of 99%.

关键词： ocean wave energy point absorbers heaving body non-floating object heave response ratio artificial neural network (ANN)