检索结果-南通市图书馆

Cross-Tier Interference mitigation in 3D HetNets for LTE and Wi-Fi Access

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Intelligent Automation & Soft Computing 2023年第1期35卷 1211-1227页

作者： m.rekha m.Bhuvaneswari Department of Electronics and Communication Engineering Dhanalakshmi Srinivasan Engineering College(Autonomous)Perambalur621212Tamil NaduIndia Department of Electronics and Communication Engineering Anna University BIT campusTiruchirappalli620024Tamil NaduIndia

Due to the unprecedented rate of transformation in thefield of wireless communication industry,there is a need to prioritise the coverage,network power and throughput as *** Heterogeneous Networks(HetNets)the low power node inclusion like Femto and Pico cells creates a network of multi-Tier(m-Tier)which is regarded as the most significant strategy for enhancing the coverage,throughput,4G Long Term Evolution(LTE)*** work mainly focuses on m-Tier 3D Heterogeneous Networks Energy Efficiency(EE)based Carrier Aggregation(CA)scheme for streaming real-time huge data like ***,m-Tier 3D HetNets scheme was made for investigating Signal to Noise Interference Ratio(SNIR)on assessing the collective Pico-tier and Femto-tier ***,the scheme of channel allocation is scrutinised so as to esti-mate throughput from the multiple ***,with the use of CA technique,the problem of energy efficiency for m-Tier 3D Heterogeneous Network(HetNet)in relation to energy metrics and throughput was evaluated with the use of LTE and Wireless Fidelity(Wi-Fi)*** simulation is carried out in a mATLAB setting,and the outcomes reveal a huge impact on *** simulation is carried in terms of EE,transmission time,throughput,packet success rate,convergence probability,and coverage *** analysis from simu-lation shows that on improving the output of the device,interference among small cell base stations is reduced on increasing *** outcomes attained aid in the effective creation of m-Tier 3D HetNets for enhancing EE by employing multi-Stream Carrier Aggregation(mSCA)in HetNets.

关键词： Heterogeneous networks multi-tier 3D HetNets energy efficiency carrier aggregation LTE Wi-Fi

Catalytic activity of manganese oxide supported on alumina in the synthesis of quinoxalines

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2013年第4期7卷 415-421页

作者： rekha m. Kathyayini H Nagaraju N Catalysis Research Laboratory St Joseph's College Post Graduate and Research Centre Bangalore 560027 India Centre for Emerging Technologies Global Campus Jain University Bangalore 562112 India

Two catalysts, alumina and manganese oxide supported on alumina, have been prepared by calcination and precipitation-impregnation methods, respectively. The catalysts are characterised by the following techniques： Brunner-Emmett-Teller-N2 adsorption-desorption for sur- face area, temperature programmed desorption of NH3 and n-butyl amine back titration methods for surface acidity, powder X-ray diffraction for textural properties, and Fourier transform infrared spectroscopy for the anionic radicals. The catalytic activity has been determined under heterogeneous conditions in the condensation reaction between o-phenylenediamine and benzil. The product purity is checked by thin-layer chromatography and melting point. The products are also analysed by LC-mS and 1H-NmR techniques. The yields of the products have been found to be good and catalysts exhibited excellent recyclability. The effect of changing the reaction para- meters such as temperature, reaction time, amount of the catalyst, nature of solvent and molar ratio of reactants on the yield of the product has been studied. The surface acidity of the catalysts plays an important role in activating the reaction.

关键词： alumina manganese oxide deposited onalumina quinoxaline synthesis

Big Data Analytics Using Swarm-Based Long Short-Term memory for Temperature Forecasting

在线全文

学校读者我要写书评

暂无评论

Computers, materials & Continua 2022年第5期71卷 2347-2361页

作者： malini m.Patil P.m.rekha Arun Solanki Anand Nayyar Basit Qureshi JSS Academy of Technical Education Bengaluru560060India Gautam Buddha University Greater Noida201312India Graduate School Duy Tan UniversityDa Nang550000Vietnam Faculty of Information Technology Duy Tan UniversityDa Nang550000Vietnam College of Computer&Info Sc Prince Sultan UniversitySaudi Arabia

In the past few decades,climatic changes led by environmental pollution,the emittance of greenhouse gases,and the emergence of brown energy utilization have led to global *** warming increases the Earth’s temperature,thereby causing severe effects on human and environmental conditions and threatening the livelihoods of millions of *** warming issues are the increase in global temperatures that lead to heat strokes and high-temperature-related diseases during the summer,causing the untimely death of thousands of *** forecast weather conditions,researchers have utilized machine learning algorithms,such as autoregressive integrated moving average,ensemble learning,and long short-term memory *** techniques have been widely used for the prediction of *** this paper,we present a swarm-based approach called Cauchy particle swarm optimization(CPSO)to find the hyperparameters of the long shortterm memory(LSTm)*** hyperparameters were determined by minimizing the LSTm validationmean square error *** optimized hyperparameters of the LSTm were used to forecast the temperature of Chennai *** proposed CPSO-LSTm model was tested on the openly available 25-year Chennai temperature *** experimental evaluation on mATLABR2020a analyzed the root mean square error rate and mean absolute error to evaluate the forecasted *** proposed CPSO-LSTm outperforms the traditional LSTm algorithm by reducing its computational time to 25 min under 200 epochs and 150 hidden neurons during *** proposed hyperparameter-based LSTm can predict the temperature accurately by having a root mean square error(RmSE)value of 0.250 compared with the traditional LSTm of 0.35 RmSE.

关键词： Climatic change big data temperature forecasting swarm intelligence deep learning

Design and development of a plastic scintillator based whole body β/γ contamination monitoring system

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2021年第5期32卷 33-42页

作者： Vaishali m.Thakur Amit Jain P.Ashokkumar rekha Anilkumar Pravin Sawant Probal Chaudhury L.m.Chaudhari Radiation Safety Systems Division Bhabha Atomic Research CentreMumbai 400085India Health Physics Division Bhabha Atomic Research CentreMumbai 400085India Department of Physics Nowrosjee Wadia CollegePuneMaharashtra 411001India

Plastic scintillation detectors based whole body β/γ contamination monitors are developed for use in radiation *** microcontroller-based multi-detector system uses 13 plastic scintillator detectors,with minimized dead detection zones,monitoring the whole body,and conforming to the contamination limit prescribed by the regulatory *** system has the features for monitoring hands,feet,head,and faceβ/γusing contamination monitors and portal exit *** can detect gamma sources at a dose rate of 10 n Gyh^(-1).The system is calibrated using b sources^(90)Sr/^(90)Y,^(204)Tl,and^(36)Cl,and the efficiency is found to be 29%,22%,and 18%,***β/γcontaminationis0.15 Bqcm^(-2),which is significantly less than the minimum detection objectives on head,face,hands,and feet.

关键词： Plastic scintillation detector Contamination monitor microcontroller minimum Detection Objective(mDO) minimum Detection Concentration(mDC)

Surrogate measures to Assess mobility of People as a Resilience Indicator in Disaster management: An Exploratory Study in Southeastern Sri Lanka

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2020年第1期11卷 13-31页

作者： A.m.Aslam Saja melissa Teo Ashantha Goonetilleke Abdul m.Ziyath K.W.G.rekha Nianthi Science and Engineering Faculty Queensland University of Technology(QUT)BrisbaneQLD 4001Australia Faculty of Arts University of PeradeniyaPeradeniya 20400Sri Lanka Faculty of Engineering South Eastern University of Sri LankaOluvil 32360Sri Lanka

Understanding social resilience can assist in the formulation of disaster management policies to help communities better prepare for, respond to, and recover from disasters. However, direct social resilience measurement methods such as household surveys are not always a practical option as they are a time-and resource-exhaustive process. Existing measures mainly utilize publicly available census data, which often provide a poor and outdated assessment of current social resilience status. Another limitation includes a failure to capture multiple facets of indicators that are process-oriented and dynamic in nature such as mobility of people. These challenges can be addressed by employing a surrogate approach. Surrogates are alternative measures to depict the target indicator. The surrogate approach can capture key facets of a target indicator, which can be used as potential measures for the target indicator. A framework to conceptualize the surrogate approach is presented, and operationalized using a case study approach on the southeastern coast of Sri Lanka to identify surrogates to measure mobility of people as a resilience indicator. Six higher-order themes were identi-fied as potential surrogates to measure mobility of people in a disaster context. The approach proposed to methodically identify potential surrogates and their measurement protocols can help to improve the current knowledge base and understanding of complex interrelationships of social resilience.

关键词： Community resilience Resilience characteristics Resilience indicators Resilience measurements Social resilience Sri Lanka

An Enhanced Security System Using Blockchain Technology for Strong FmC Relationship

在线全文

学校读者我要写书评

暂无评论

Intelligent Automation & Soft Computing 2023年第1期35卷 111-128页

作者： K.meenakshi K.Sashi rekha Department of Computer Science and Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical SciencesChennaiIndia

Blockchain technology is a shared database of logs of all consumer transactions which are registered on all machines on a *** transactions in the system are carried out by consensus processes and to preserve confidentiality all thefiles contained cannot be *** technology is the fundamental software behind digital currencies like Bitcoin,which is common in the *** computing is a method of using a network of external machines to store,monitor,and process information,rather than using the local computer or a local personal *** software is currently facing multiple problems including lack of data protection,data instability,and *** paper aims to give the highest security for multiple user environments in cloud for storing and accessing the data in *** users who are legitimate are only allowed for storing and accessing the data as like a secured block chain *** like the Blockchain which does not require a centralized system for transactions,the proposed system is also independent on centralized network *** decentralized system is developed in such a way to avoid *** system enables the fabricator to spend less or null resources to perform the validations for its direct operated *** ensures the product fabricator to avoid the circulation of its duplicate *** customer as an end-user is also ensured to have only the genuine products from the *** Fabricator(F),merchant(m)and consumer(C)forms an interconnected triangular structure without allowing any counterfeiting agents in their secured cloud *** pro-posed approach provides the stability in the security system of the cloud using the chaining mechanism within different blocks at each *** takes roughly 4.7,6.2,and 7.5 ms,respectively,to register each node in the proposed system for 5,10,and 15 *** overall registration time for each scenario is 11.9,26.2,and 53.1 ms,despite the fact th

关键词： Blockchain bitcoin customer merchant data protection digital currencies transaction

Analysis of Carbaryl Pesticide Residues in Environmental Samples with Spectrophotometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2006年第8期24卷 1095-1100页

作者： rekha, Dasari SUVARDHAN, Kanchi KUmAR, Kailasa Suresh JAYARAJ, Bellum CHIRANJEEVI, Pattium Department of mathematics Sri Venkateswara University Tirupati-517502 A.P. INDIA Environmental monitoring Laboratories Department of Chemistry Sri Venkateswara University Tirupati-517502. A.P. INDIA

A facile, rapid and sensitive spectrophotometric method was developed for the determination of carbaryl in its formulations, water and grain （rice and wheat） samples with newly synthesised reagent. The proposed method was based on the alkaline hydrolysis of carbaryl pesticide and thus resulted 1-naphthol was coupled with diazotised 4,4＇-methylene-bis-m-nitroaniline in basic medium （pH 9） to give red colored product having λmax 480 nm for diazonium method （Dm） or 1-naphthol reacts with 4,4＇-methylene-bis-m-nitroaniline in the presence of oxidising agent potassium dichromate （K2Cr2O7） to give red colored product having λmax 510 nm for oxidation method （Om）. The formation of colored derivatives with the coupling agent is instantaneous and stable for 48 h （Dm） and 32 h （Om） respectively. Beer＇s law was obeyed in the concentration range of 0.2--10.0 μg·mL ^-1 for Dm and 0.2--0.150 μg·mL^-1 for Om. The proposed methods are sensitive, easy to operate and permitted for the determination of carbaryl with detection limits of 0.028 μg·mL^-1 for Dm and 0.024 μg·mL^-1 for Om respectively. The experimental results indicate that the procedure can eliminate the fundamental interferences caused by other pesticides and non-target ions, which made the methods more sensitive and selective. The method was applicable to the determination of carbaryl residue in water and food grain samples up to μg level.

关键词： carbaryl 4,4'-methylene-bis-m-nitroaniline. diazotisation method (Dm) oxidation method (Om),spectrophotometry water and grain samples

Design and analysis of high birefringence and nonlinearity with small confinement loss photonic crystal fiber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Optoelectronics 2019年第2期12卷 165-173页

作者： rekha SAHA md.mahbub HOSSAIN md. Ekhlasur RAHAmAN Himadri Shekhar mONDAL Electronics and Communication Engineering Discipline Khulna UniversityKhulna 9208Bangladesh

High birefringence with low confinement loss photonic crystal fiber (PCF) has significant advantages in the field of sensing, dispersion compensation devices, nonlinear applications, and polarization filter. In this report, two different models of PCFs are presented and compared. Both the models contain five air holes rings with combination of circular and elliptical air holes arrangement. moreover, the elliptical shaped air holes polarization and the third ring air holes rotational angle are varied. To examine different guiding characteristics, finite element method (FEm) with perfectly matched layer (PmL) absorbing boundary condition is applied from 1.2 to 1.8 |im wavelength range. High birefringence, low confinement loss, high nonlinearity, and moderate disper-sion values are successfully achieved in both the PCFs models. Numeric analysis shows that model-1 gives higher birefringence (2.75 ×10^-2) and negative dispersion (-540.67 ps/(nm ·km)) at 1.55 |im wavelength. However, model-2 gives more small confinement loss than model-1 at the same wavelength. In addition, the proposed design demonstrates the variation of rotation angle has great impact to enhance guiding properties especially the birefringence.

关键词： birefringence dispersion polarization main-taining photonic crystal fiber (PCF) polarization-selective devices polarization

氧化铝和氧化锆催化剂上2-取代苯并咪唑和1,5-二取代苯并二氮的合成(英文)

在线全文

学校读者我要写书评

暂无评论

催化学报 2012年第3期33卷 439-446页

作者： m. rekha A. HAmZA B. R. VENUGOPAL N. NAGARAJU Catalysis Research Laboratory St. Joseph's College and Research Centre 39 Lalbagh Road Shanthinagar Bangalore 560 027 India Laboratory of Chemistry and Electrochemistry of Surfaces Facultés Universitaires Notre-Dame de la Paix Rue de Bruxelles 61 B-5000 Namur Belgium

In this study, alumina, zirconia, manganese oxide/alumina, and manganese oxide/zirconia have been investigated for their catalytic activity in the condensation reaction between o-phenylenediamine and an aldehyde or a ketone to synthesise 2-substituted benzimidazoles and 1,5-disubstituted benzodiazepines respectively. Surface area, surface acidity, and morphology of the catalysts have been analysed and correlated with their catalytic activity. The isolated yields of 2-substituted benzimidazoles and 1,5-disubstituted benzodiazepines are in the range of 30% to 95%. A good correlation between the amount of surface acid sites as well as the surface morphology of the catalysts and the catalytic activity has been observed. This method has been found to be simple and economical. The solid supports could be regenerated and reused without much loss in their activity. Further, the solid supports have been also found to be effective as general catalysts in the condensation of o-phenylenediamine with other substituted aldehydes and ketones.

关键词：取代苯并咪唑锆催化剂二取代苯氧化铝合成药物催化活性氮