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Fuzzy Decision-Based Clustering for Efficient Data Aggregation in Mobile UWSNs
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作者 Aadil Mushtaq Pandith Manni kumar +5 位作者 naveen kumar Nitin Goyal Sachin Ahuja Yonis Gulzar Rashi Rastogi Rupesh Gupta 《Computers, Materials & Continua》 2025年第4期259-279,共21页
Underwater wireless sensor networks(UWSNs)rely on data aggregation to streamline routing operations by merging information at intermediate nodes before transmitting it to the sink.However,many existing data aggregatio... Underwater wireless sensor networks(UWSNs)rely on data aggregation to streamline routing operations by merging information at intermediate nodes before transmitting it to the sink.However,many existing data aggregation techniques are designed exclusively for static networks and fail to reflect the dynamic nature of underwater environments.Additionally,conventional multi-hop data gathering techniques often lead to energy depletion problems near the sink,commonly known as the energy hole issue.Moreover,cluster-based aggregation methods face significant challenges such as cluster head(CH)failures and collisions within clusters that degrade overall network performance.To address these limitations,this paper introduces an innovative framework,the Cluster-based Data Aggregation using Fuzzy Decision Model(CDAFDM),tailored for mobile UWSNs.The proposed method has four main phases:clustering,CH selection,data aggregation,and re-clustering.During CH selection,a fuzzy decision model is utilized to ensure efficient cluster head selection based on parameters such as residual energy,distance to the sink,and data delivery likelihood,enhancing network stability and energy efficiency.In the aggregation phase,CHs transmit a single,consolidated set of non-redundant data to the base station(BS),thereby reducing data duplication and saving energy.To adapt to the changing network topology,the re-clustering phase periodically updates cluster formations and reselects CHs.Simulation results show that CDAFDM outperforms current protocols such as CAPTAIN(Collection Algorithm for underwater oPTical-AcoustIc sensor Networks),EDDG(Event-Driven Data Gathering),and DCBMEC(Data Collection Based on Mobile Edge Computing)with a packet delivery ratio increase of up to 4%,an energy consumption reduction of 18%,and a data collection latency reduction of 52%.These findings highlight the framework’s potential for reliable and energy-efficient data aggregation mobile UWSNs. 展开更多
关键词 CLUSTERING data aggregation data collection fuzzy model MONITORING UWSN
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Endoscopic management for gastrointestinal leaks,perforations,and fistulae:Technical tips and outcomes
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作者 Chhagan L Birda Jahnvi Dhar +8 位作者 naveen kumar Shubhra Mishra Giuseppe Dell'Anna Cherring Tandup Satish S Nagaraj Stefano F Crinò Vikramjit Mitra Zaheer Nabi Jayanta Samanta 《World Journal of Gastrointestinal Endoscopy》 2025年第12期10-30,共21页
Gastrointestinal(GI)tract defects can be classified into three distinct entities:Leak,perforation,and fistula.Each arises from different mechanisms and is managed accordingly.Leaks occur most often after surgery,while... Gastrointestinal(GI)tract defects can be classified into three distinct entities:Leak,perforation,and fistula.Each arises from different mechanisms and is managed accordingly.Leaks occur most often after surgery,while perforations arise due to flexible endoscopic maneuvers.Fistulae arise from a variety of mechanisms,including specific disease states.Endoscopic management is vital in treating such defects if the region of interest can be accessed with the appropriate endoscopic accessories.The primary goal of endoscopic therapy is to interrupt the flow of luminal contents across a GI defect.Considering the proper endoscopic approach to luminal closure,several basic principles must be considered.Outcomes are dependent on the size and exact location of the leak/fistula,as well as the viability of the surrounding tissue.Almost all complex leaks and fistulae must be approached in a multidisciplinary manner,collaborating with colleagues in nutrition,radiology,and surgery.With advances in technology,a myriad of devices and accessories are available that allow a tailored approach.In this review,we discuss these modalities,provide technical tips,and review published outcomes data regarding each approach,as well as practical considerations for the successful closure of these defects. 展开更多
关键词 LEAK Clip Metal stent Endoscopy Surgery IATROGENIC
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Electronic modulation of MOF-engineered bimetallic phosphides for cost-effective ampere-level water splitting and continuous hydrogen production via supercapacitor integration
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作者 Mohd Afshan naveen kumar +9 位作者 Subhabrata Das Harini E.M Daya Rani Soumyadip Sharangi Mansi Pahuja Shumile Ahmed Siddiqui Seema Rani Nikita Chaudhary Chandan Bera Kaushik Ghosh 《Journal of Energy Chemistry》 2025年第9期221-238,I0008,共19页
Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction ... Engineering a phosphide-based multifunctional heterostructure with high redox activity,stability,and efficient charge kinetics for both supercapacitors and water splitting remains challenging due to sluggish reaction kinetics and structural instability.This study overcomes these challenges by implementing a rapid,energy-efficient approach to develop a MOF-modulated MnP@Cu_(3)P heterostructure via a hydrothermal process followed by high-temperature phosphorization.The heterostructure demonstrates superior redox activity with enhanced stability and improved charge kinetics achieving a high specific capacity of 1131 C g^(-1)as supported by density functional theory findings of increased DOS near the Fermi level.The flexible supercapacitor achieves a peak energy density of 99.20 Wh kg^(-1)and power density of 15.40 kW kg^(-1).Simultaneously,it shows exceptional hydrogen evolution reaction performance with an overpotential of η_(10)=44 mV and η_(1000)=225 mV,attributed to electron transfer from Cu to Mn via P bridging,which shifts the active centers from Mn and Cu sites to the P site,confirmed by lowestΔG_(H)^(*)value of-0.16 eV.The overall water-splitting in full-cell electrocatalyzer delivers cell voltage of E_(20)=1.48 V and E_(1000)=1.88 V and setting a new standard in solar-to-hydrogen efficiency of 20.02%.The electrolyzer cell maintained prolonged stability at industrial-scale current densities of 1.0 A cm^(-2)under alkaline electrolysis achieving an estimated hydrogen production cost of INR 146.7 or US$1.67per kilogram aligning with the cost target of $2/kg by 2026 established by the Clean Hydrogen Electrolysis Program,U.S.department of energy.Furthermore,real-phase demonstration highlights the uninterrupted hydrogen production till 6-minutes via connecting this electrocatalyzer with photovoltaic-charged supercapacitors effectively addressing solar intermittency and gas fluctuations challenges in water-electrolysis. 展开更多
关键词 Bimetallic phosphides Interface engineering Hybrid supercapacitors Solar-to-hydrogen conversion Ampere level current density
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Strategy and Future Prospects to Develop Room-Temperature-Recoverable NO2 Gas Sensor Based on Two-Dimensional Molybdenum Disulfide 被引量:11
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作者 Abhay V.Agrawal naveen kumar Mukesh kumar 《Nano-Micro Letters》 SCIE EI CAS CSCD 2021年第2期305-362,共58页
Nitrogen dioxide(NO2),a hazardous gas with acidic nature,is continuously being liberated in the atmosphere due to human activity.The NO2 sensors based on traditional materials have limitations of high-temperature requ... Nitrogen dioxide(NO2),a hazardous gas with acidic nature,is continuously being liberated in the atmosphere due to human activity.The NO2 sensors based on traditional materials have limitations of high-temperature requirements,slow recovery,and performance degradation under harsh environmental conditions.These limitations of traditional materials are forcing the scientific community to discover future alternative NO2 sensitive materials.Molybdenum disulfide(MoS2)has emerged as a potential candidate for developing next-generation NO2 gas sensors.MoS2 has a large surface area for NO2 molecules adsorption with controllable morphologies,facile integration with other materials and compatibility with internet of things(IoT)devices.The aim of this review is to provide a detailed overview of the fabrication of MoS2 chemiresistance sensors in terms of devices(resistor and transistor),layer thickness,morphology control,defect tailoring,heterostructure,metal nanoparticle doping,and through light illumination.Moreover,the experimental and theoretical aspects used in designing MoS2-based NO2 sensors are also discussed extensively.Finally,the review concludes the challenges and future perspectives to further enhance the gas-sensing performance of MoS2.Understanding and addressing these issues are expected to yield the development of highly reliable and industry standard chemiresistance NO2 gas sensors for environmental monitoring. 展开更多
关键词 MOS2 NO2 gas sensors Light illumination HETEROJUNCTION
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Relative active tectonics evaluation using geomorphic and drainage indices, in Dadra and Nagar Haveli, western India 被引量:6
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作者 naveen kumar Rakesh K.Dumka +1 位作者 Kapil Mohan Sumer Chopra 《Geodesy and Geodynamics》 CSCD 2022年第3期219-229,共11页
The present study area,Dadra and Nagar Haveli,contains several lineaments and traces of active faults.The various aspect of the geomo rphic analysis,i.e.,stream length(SL) gradient,hypsometric integral(HI),basin shape... The present study area,Dadra and Nagar Haveli,contains several lineaments and traces of active faults.The various aspect of the geomo rphic analysis,i.e.,stream length(SL) gradient,hypsometric integral(HI),basin shape(BS),valley floor(VF),have been applied to evaluate the relative index of active tectonics(RIAT) of the Damanganga watershed.The high and low zones of tectonic activity have been identified based on the geomorphic analysis of the watershed.After evaluation of all indices,three classes,class IIhigh(1.3 ≤RIAT <1.5),class Ⅲ-moderate(1.5 ≤RIAT <1.8),and class Ⅳ-low(1.8 ≤RIAT),have been obtained to outline the degree/gradation of comparative tectonic activities in the study area.The appraised outcome of the RIAT dispersal is also well reinforced by the geomorphic evidence in the field.The collective outcomes of geomorphic evidence,such as stream deflection and analysis of lineament,deflection of streams,and geomorphic indices,conceal that the Damanganga watershed is affected by tectonic activity. 展开更多
关键词 Active tectonics Geomorphic indices Relative index of active tectonics(RIAT) Drainage indices
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Antitubercular therapy in patients with cirrhosis:Challenges and options 被引量:3
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作者 naveen kumar Chandan kumar Kedarishetty +2 位作者 Sachin kumar Vikas Khillan Shiv kumar Sarin 《World Journal of Gastroenterology》 SCIE CAS 2014年第19期5760-5772,共13页
Tuberculosis(TB)has been a human disease for centuries.Its frequency is increased manyfold in patients with liver cirrhosis.The gold standard of TB management is a 6-mo course of isoniazid,rifampicin,pyrazinamide and ... Tuberculosis(TB)has been a human disease for centuries.Its frequency is increased manyfold in patients with liver cirrhosis.The gold standard of TB management is a 6-mo course of isoniazid,rifampicin,pyrazinamide and ethambutol.Although good results are seen with this treatment in general,the management of patients with underlying cirrhosis is a challenge.The underlying depressed immune response results in alterations in many diagnostic tests.The tests used for latent TB have many flaws in this group of patients.Three of four first-line antitubercular drugs are hepatotoxic and baseline liver function is often disrupted in patients with underlying cirrhosis.Frequency of hepatotoxicity is increased in patients with liver cirrhosis,frequently leading to severe liver failure.There are no established guidelines for the treatment of TB in relation to the severity of liver disease.There is no consensus on the frequency of liver function tests required or the cutoff used to define hepatotoxicity.No specific treatment exists for prevention or treatment of hepatotoxicity,making monitoring even more important.A high risk of multidrug-resistant TB is another major worry due to prolonged and interrupted treatment. 展开更多
关键词 Antitubercular therapy Drug hepatotoxicity Multidrug-resistant tuberculosis Immune dysfunction
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Atypical respiratory complications of dengue fever 被引量:1
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作者 naveen kumar AK Gadpayle Deepshikha Trisal 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第10期839-840,共2页
In last decade,dengue has emerged as one of the most important vector born disease.With increasing cases,uncommon presentations and complications are now commonly recognized.Here,we report two cases of rare pattern of... In last decade,dengue has emerged as one of the most important vector born disease.With increasing cases,uncommon presentations and complications are now commonly recognized.Here,we report two cases of rare pattern of respiratory involvement in dengue:acute respiratory distress syndrome and bronchiolitis with respiratory failure. 展开更多
关键词 RESPIRATORY COMPLICATION Acute RESPIRATORY DISTRESS syndrome VIRAL BRONCHIOLITIS
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Temperature effect on the dynamic adsorption of anionic surfactants and alkalis to silica surfaces 被引量:1
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作者 Marco Masulli Zi-Long Liu +3 位作者 Feng-Zhi Guo Xue Li Ernst J.RSudholter naveen kumar 《Petroleum Science》 SCIE CAS CSCD 2022年第4期1866-1876,共11页
Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR).Here,we investigated the adsorption behaviors of anionic surfactants and alkali... Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR).Here,we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D).The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS)surfactant can be quantitatively described by the thermodynamics parameters of micellization,showing a mainly entropy-driven process.AAS adsorption was mediated under varying temperature conditions,by divalent cations for bridging effect,monovalent cations competitive for adsorption sites but not giving cation bridging,pH regulation of deprotonated sites of silica,presence of alkoxy groups in the surfactants,and synergistic effect of surfactant coinjection.The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3)had capability of the sequestration of the divalent ions,whose addition would reduce AAS adsorption.The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers,with a likely compact bilayer followed by disorganized and unstable further layering.The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies. 展开更多
关键词 TEMPERATURE SURFACTANT ALKALI ADSORPTION Enhanced oil recovery
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Blockchain Economics and Marketing 被引量:1
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作者 Frank T. Lorne Sriram Daram +3 位作者 Rutha Frantz naveen kumar Athif Mohammed Amit Muley 《Journal of Computer and Communications》 2018年第12期107-117,共11页
Blockchain as a supporting platform for various cryptocurrencies is a technology that will not sell by itself, meaning that its success could not be built on technical efficiency of an algorithm alone. Understanding t... Blockchain as a supporting platform for various cryptocurrencies is a technology that will not sell by itself, meaning that its success could not be built on technical efficiency of an algorithm alone. Understanding the real economic problems that the technology should aim at solving is a first step towards identifying the marketing beachheads for the technology. The branding of any blockchain can be categorized under an economic framework pointing to the types that have the potentials of being sustainable and disruptive. Selection of appropriate beachheads, verticals, services etc. should aim to promote the exchange of real goods and services, and/or the utilization the accounting/data advantage of the technology. 展开更多
关键词 TRANSACTION COSTS Cryptoeconomics MARKETING
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Treating morbid obesity in cirrhosis: A quest of holy grail
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作者 naveen kumar Narendra Singh Choudhary 《World Journal of Hepatology》 CAS 2015年第28期2819-2828,共10页
The problem of obesity is increasing worldwide in epidemic proportions; the situation is similarly becoming more common in patients with cirrhosis which negatively affect the prognosis of disease and also makes liver ... The problem of obesity is increasing worldwide in epidemic proportions; the situation is similarly becoming more common in patients with cirrhosis which negatively affect the prognosis of disease and also makes liver transplantation difficult especially in the living donor liver transplantation setting where low graft to recipientweight ratio negatively affects survival. Treatment of obesity is difficult in cirrhosis due to difficulty in implementation of lifestyle measures, limited data on safety of anti-obesity drugs and high risk of surgery. Currently approved anti-obesity drugs have limited data in patients with cirrhosis. Bariatric surgery remains an option in selected compensated cirrhotic patients. Endoscopic interventions for obesity are emerging and are quite promising in patients with cirrhosis as these are minimally invasive. In present review, we briefly discuss various modalities of weight reduction in obese patients and their applicability in patients with cirrhosis. 展开更多
关键词 OBESITY Intragastric BALLOON Antiobesitydrugs BARIATRIC surgery CIRRHOSIS
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Technologically Advanced Reusable 3D Face Shield for Health Workers Confronting COVID19
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作者 Rajesh kumar Kaushal naveen kumar +4 位作者 Vinay Kukreja Fahd S.Alharithi Ahmed H.Almulihi Arturo Ortega Mansilla Shikha Rani 《Computers, Materials & Continua》 SCIE EI 2022年第8期2565-2579,共15页
The probability of medical staff to get affected from COVID19 is much higher due to their working environment which is more exposed to infectious diseases.So,as a preventive measure the body temperature monitoring of ... The probability of medical staff to get affected from COVID19 is much higher due to their working environment which is more exposed to infectious diseases.So,as a preventive measure the body temperature monitoring of medical staff at regular intervals is highly recommended.Infrared temperature sensing guns have proved its effectiveness and therefore such devices are used to monitor the body temperature.These devices are either used on hands or forehead.As a result,there are many issues in monitoring the temperature of frontline healthcare professionals.Firstly,these healthcare professionals keep wearing PPE(Personal Protective Equipment)kits during working hours and as a result it would be very difficult to monitor their body temperature.Secondly,these healthcare professionals also wear face shields and in such cases monitoring temperature by exposing forehead needs removal of face shield.Doing so after regular intervals is surely uncomfortable for healthcare professionals.To avoid such issues,this paper is disclosing a technologically advanced face shield equipped with sensors capable of monitoring body temperature instantly without the hassle of removing the face shield.This face shield is integrated with a built-in infrared temperature sensor.A total of 10 such face shields were printed and assembled within the university lab and then handed over to a group of ten members including faculty and students of nursing and health science department.This sequence was repeated four times and as a result 40 healthcare workers participated in the study.Thereafter,feedback analysis was conducted on questionnaire data and found a significant overall mean score of 4.59 out of 5 which indicates that the product is effective and worthy in every facet.Stress analysis is also performed in the simulated environment and found that the device can easily withstand the typically applied forces.The limitations of this product are difficulty in cleaning the product and comparatively high cost due to the deployment of electronic equipment. 展开更多
关键词 Temperature sensing face shield electronic 3D face shield IoT enabled face-shield
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Multiple tendons of the additional belly of flexor pollicis longus in the carpal tunnel: Embryological perspective and their clinical significance
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作者 Ravindra Swamy Shantakumar Srinivasa Rao Sirasanagandla +3 位作者 Satheesha Badagabettu Nayak Mohandas Rao Kappettu Gadahad Shiroor Nagabhushan Somayaji naveen kumar 《Forensic Medicine and Anatomy Research》 2013年第4期70-73,共4页
Although the flexor pollicis longus is known to show the additional head of the origin, the occurrence of its additional tendons in the carpal tunnel are seldom reported. The presence of such additional tendons in the... Although the flexor pollicis longus is known to show the additional head of the origin, the occurrence of its additional tendons in the carpal tunnel are seldom reported. The presence of such additional tendons in the carpal tunnel cannot be overlooked during the radiological and surgical procedures in this region. Herein, we report a rare case of additional muscle belly of flexor pollicis longus. The additional muscle belly after a short course divided into three tendons. All three tendons entered the carpal tunnel along with flexor pollicis longus, passing deep to the flexor retinaculum. Within the carpal tunnel, two of these tendons fused and terminated by merging with the undersurface of the flexor retinaculum. The third tendon terminated by joining the flexor digitorum superficialis tendon for the index finger, in the palm. An additional slip of the first lumbrical muscle took origin from the third tendon of the additional muscle belly of flexor pollicis longus. Further, the embryological basis and clinical significance of current case is discussed. 展开更多
关键词 FLEXOR Pollicis Longus Additional MUSCLE Belly FLEXOR RETINACULUM CARPAL TUNNEL First Lumbrical
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S-,N-and C-doped ZnO as semiconductor photocatalysts:A review 被引量:3
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作者 Vijaya kumarI Anuj MITTAL +2 位作者 Jitender JINDAL Suprabha YADAV naveen kumar 《Frontiers of Materials Science》 SCIE CSCD 2019年第1期1-22,共22页
In the past few decades,many novel non-metal doped ZnO materials have developed hasty interest due to their adaptable properties such as low recombination rate and high activity under the solar light exposure.In this ... In the past few decades,many novel non-metal doped ZnO materials have developed hasty interest due to their adaptable properties such as low recombination rate and high activity under the solar light exposure.In this article,we compiled recent research advances in non-metal(S,N,C)doped ZnO,emphasizing on the related mechanism of catalysis and the effect of non-metals on structural,morphological,optical and photocatalytic characteristics of ZnO.This review will enhance the knowledge about the advancement in ZnO and will help in synthesizing new ZnO-based materials with modified structural and photocatalytic properties. 展开更多
关键词 DEGRADATION recombination MECHANISM PHOTOCATALYST POLLUTANT
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Security Attacks in Named Data Networking: A Review and Research Directions 被引量:1
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作者 naveen kumar Ashutosh kumar Singh +1 位作者 Abdul Aleem Shashank Srivastava 《Journal of Computer Science & Technology》 SCIE EI CSCD 2019年第6期1319-1350,共32页
Contents such as audios,videos,and images,contribute most of the Internet traffic in the current paradigm.Secure content sharing is a tedious issue.The existing security solutions do not secure data but secure the com... Contents such as audios,videos,and images,contribute most of the Internet traffic in the current paradigm.Secure content sharing is a tedious issue.The existing security solutions do not secure data but secure the communicating endpoints.Named data networking(NDN)secures the data by enforcing the data publisher to sign the data.Any user can verify the data by using the public key of the publisher.NDN is resilient to most of the probable security attacks in the TCP/IP model due to its new architecture.However,new types of attacks are possible in NDN.This article surveys the most significant security attacks in NDN such as interest flooding attacks,cache privacy attacks,cache pollution attacks,and content poisoning attacks.Each attack is classified according to their behavior and discussed for their detection techniques,countermeasures,and the affected parameters.The article is an attempt to help new researchers in this area to gather the domain knowledge of NDN.The article also provides open research issues that could be addressed by researchers. 展开更多
关键词 named data networking(NDN) interest flooding attack cache privacy attack cache pollution attack content poisoning attack
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Bibliometric analysis of Blockchain in the healthcare domain 被引量:1
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作者 Shilpi Garg Rajesh kumar Kaushal +1 位作者 naveen kumar Anshul Verma 《Intelligent and Converged Networks》 EI 2023年第4期305-312,共8页
As an innovation,Blockchain has transformed numerous industries and sparked the interest of the research community due to its abundance of benefits,opening up diverse research routes in the healthcare sector in the la... As an innovation,Blockchain has transformed numerous industries and sparked the interest of the research community due to its abundance of benefits,opening up diverse research routes in the healthcare sector in the last decade.With Health 4.0 becoming ubiquitous in the healthcare industry,end-user transactions are being carried out on a decentralized network,making Blockchain profitable to meet the demands of the modern healthcare sector.Therefore,a detailed analysis of Blockchain is very crucial.This study emphasizes the evolution of science and the preliminary research of Blockchain in healthcare through bibliometric analysis.All the data are extracted from the Scopus database,and the VOSviewer tool is used for analysis.A total of 1152 Scopus articles published between 2018 and 2022 are examined.Results reveal that in 2022,the field of Blockchain experienced a notable increment in the number of publications and a significant growth rate.IEEE Access became well known in this field and had a large number of citations.It is observed that China and India are the leading countries in terms of publications on Blockchain.This study offers a number of recommendations that amateur and professional researchers can use as a benchmark before commencing a Blockchain investigation in the future. 展开更多
关键词 Blockchain BIBLIOMETRIC healthcare VOSviewer
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A square lattice topology coordination network that exhibits highly selectiveC_(2)H_(2)/CO_(2)separation performance 被引量:1
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作者 naveen kumar Soumya Mukherjee +8 位作者 Andrey A.Bezrukov Matthias Vandichel Mohana Shivanna Debobroto Sensharma Alankriti Bajpai Victoria Gascón Ken‐ichi Otake Susumu Kitagawa Michael J.Zaworotko 《SmartMat》 2020年第1期48-55,共8页
C_(2)H_(2)/CO_(2)separation is an industrially important process that remains challenging because of the similar physicochemical properties of C_(2)H_(2)and CO_(2).We herein report that the new square lattice(sql)coor... C_(2)H_(2)/CO_(2)separation is an industrially important process that remains challenging because of the similar physicochemical properties of C_(2)H_(2)and CO_(2).We herein report that the new square lattice(sql)coordination network[Cu(bipy‐xylene)2(NO3)2]n,sql‐16‐Cu‐NO3,16=bipy‐xylene=4,4′‐(2,5‐dimethyl‐1,4‐phenylene)dipyridine,exists in at least three forms,as‐synthesised(α),activated(α′)and hydrated(β).The activated phase,sql‐16‐Cu‐NO3‐α′,is an ultramicroporous material that exhibits high selectivity towards C_(2)H_(2)over CO_(2)as revealed by dynamic gas breakthrough experiments(1:1,C_(2)H_(2)/CO_(2))that afforded 99.87%pure CO_(2)in the effluent stream.The separation selectivity at 298 K and 1 bar,78,is the third best value yet reported for C_(2)H_(2)selective physisorbents whereas the mid‐loading performance sets a new benchmark.The performance of sql‐16‐Cu‐NO3‐α′is attributed to a new type of C_(2)H_(2)binding site in which CH···ONO2 interactions enable moderately strong sorbent‐sorbate binding(Qst(C_(2)H_(2))=38.6 kJ/mol)at low loading.Conversely,weak CO_(2)binding(Qst(CO_(2))=25.6 kJ/mol)at low loading means that(ΔQst)AC[Qst(C_(2)H_(2))–Qst(CO_(2))]is 13 kJ/mol at low coverage and 11.4 kJ/mol at mid‐loading.Analysis of in situ powder X‐ray diffraction and modelling experiments provide insight into the sorption properties and high C_(2)H_(2)/CO_(2)separation performance of sql‐16‐Cu‐NO3‐α′. 展开更多
关键词 ACETYLENE ADSORPTION coordination networks crystal engineering ultramicroporosity
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Design and optimization analysis of dual material gate on DG-IMOS
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作者 Sarabdeep Singh Ashish Ramant naveen kumar 《Journal of Semiconductors》 EI CAS CSCD 2017年第12期48-55,共8页
An impact ionization MOSFET (IMOS) is evolved for overcoming the constraint of less than 60 mV/decade sub-threshold slope (SS) of conventional MOSFET at room temperature. In this work, first, the device performanc... An impact ionization MOSFET (IMOS) is evolved for overcoming the constraint of less than 60 mV/decade sub-threshold slope (SS) of conventional MOSFET at room temperature. In this work, first, the device performance of the p-type double gate impact ionization MOSFET (DG-IMOS) is optimized by adjusting the device design parameters. The adjusted parameters are ratio of gate and intrinsic length, gate dielectric thickness and gate work function. Secondly, the DMG (dual material gate) DG-IMOS is proposed and investigated. This DMG DG-IMOS is further optimized to obtain the best possible performance parameters. Simulation results reveal that DMG DG-IMOS when compared to DG-IMOS, shows better IoN, ION/IoFF ratio, and RF parameters. Results show that by properly tuning the lengths of two materials at a ratio of 1.5 in DMG DG-IMOS, optimized perform- ance is achieved including ION/IoFF ratio of 2.87 × 10^9 A/μm with/ON as 11.87 × 10^-4 A/μm and transconductance of 1.06× 10^-3 S/μm. It is analyzed that length of drain side material should be greater than the length of source side material to attain the higher transconductance in DMG DG-IMOS. 展开更多
关键词 impact ionization MOSFET (IMOS) avalanche breakdown sub-threshold slope dual material gate (DMG) BIOSENSOR
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Finite-size-effect on a very large length scale in NBT-based lead-free piezoelectrics
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作者 Anupam Mishra Dipak kumar Khatua +3 位作者 Gobinda Das Adhikary naveen kumar Uma Shankar Rajeev Ranjany 《Journal of Advanced Dielectrics》 CAS 2019年第5期35-41,共7页
Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer applications.We have examined the role of grain size ... Na_(0.5)Bi_(0.5)TiO_(3)-based lead-free piezoelectrics are considered for potential replacement of the lead-based commercial piezoceramics in high-power transducer applications.We have examined the role of grain size in influencing the structural-polar inhomogeneity of stoichiometric and off-stoichiometric Na_(0.5)Bi_(0.5)TiO_(3)(NBT),and its morphotropic-phase-boundary(MPB)derivative 0.94Na_(0.5)Bi_(0.5)TiO_(3)-0.06BaTiO_(3)(NBT-6BT).Our study reveals that size effect comes into play in these systems on a very large length scale(on the scale of microns)considerably affecting its global structure and properties. 展开更多
关键词 Lead-free piezoelectrics Na_(0.5)Bi_(0.5)TiO_(3) size effect crystal structure depolarization temperature
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Comprehensive evaluation of key management hierarchies for outsourced data
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作者 naveen kumar Anish Mathuria 《Cybersecurity》 CSCD 2019年第1期150-166,共17页
Key management is an essential component of a cryptographic access control system with a large number of resources.It manages the secret keys assigned to the system entities in such a way that only authorized users ca... Key management is an essential component of a cryptographic access control system with a large number of resources.It manages the secret keys assigned to the system entities in such a way that only authorized users can access a resource.Read access control allows read access of a resource by the authorized users and disallows others.An important objective of a key management is to reduce the secret key storage with each authorized user.To this end,there exist two prominent types of key management hierarchy with single key storage per user used for read access control in data outsourcing scenario:user-based and resource-based.In this work,we analyze the two types of hierarchy with respect to static hierarchy characteristics and dynamic operations such as adding or revoking user authorization.Our analysis shows that the resource-based hierarchies can be a better candidate which is not given equal emphasis in the literature.A new heuristic for minimizing the key management hierarchy is introduced that makes it practical in use even for a large number of users and resources.The performance evaluation of dynamic operations such as adding or revoking a user’s read subscription is shown experimentally to support our analytical results. 展开更多
关键词 Key management hierarchy Data outsourcing Access control
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Comprehensive evaluation of key management hierarchies for outsourced data
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作者 naveen kumar Anish Mathuria 《Cybersecurity》 2018年第1期425-441,共17页
Key management is an essential component of a cryptographic access control system with a large number of resources.It manages the secret keys assigned to the system entities in such a way that only authorized users ca... Key management is an essential component of a cryptographic access control system with a large number of resources.It manages the secret keys assigned to the system entities in such a way that only authorized users can access a resource.Read access control allows read access of a resource by the authorized users and disallows others.An important objective of a key management is to reduce the secret key storage with each authorized user.To this end,there exist two prominent types of key management hierarchy with single key storage per user used for read access control in data outsourcing scenario:user-based and resource-based.In this work,we analyze the two types of hierarchy with respect to static hierarchy characteristics and dynamic operations such as adding or revoking user authorization.Our analysis shows that the resource-based hierarchies can be a better candidate which is not given equal emphasis in the literature.A new heuristic for minimizing the key management hierarchy is introduced that makes it practical in use even for a large number of users and resources.The performance evaluation of dynamic operations such as adding or revoking a user’s read subscription is shown experimentally to support our analytical results. 展开更多
关键词 Key management hierarchy Data outsourcing Access control
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