Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes...Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.展开更多
Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidel...Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.展开更多
BACKGROUND Development of pericardial effusion in patients with left ventricular assist devices(LVADs)can be detrimental to health outcomes.This study aims to elucidate the prevalence and risk factors for pericardial ...BACKGROUND Development of pericardial effusion in patients with left ventricular assist devices(LVADs)can be detrimental to health outcomes.This study aims to elucidate the prevalence and risk factors for pericardial effusion in patients with LVADs.AIM To elucidate risk factors associated with the presence of pericardial effusion in patients with LVADs and compare the clinical outcomes of those with and without pericardial effusion.The secondary goal is to determine the incidence of pericardiocentesis and pericardial window placement in patients with LVADs experiencing pericardial effusion.METHODS Data were obtained from the National Inpatient Sample database between 2016 and 2018.Statistical analysis was performed using Pearsonχ2 test and multivariate logistic regression analysis to determine clinical outcomes of pericardial effusion and to identify variables associated with pericardial effusion in LVAD patients,respectively.RESULTS The prevalence of LVAD was 9850(0.01%)among total study patients(n=98112095).The incidence of pericardial effusion among LVAD patients was 640(6.5%).The prevalence of liver disease(26.6%vs 17.4%),chronic kidney disease(CKD;54.6%vs 49.4%),hypothyroidism(21.9%vs 18.1%),congestive heart failure(98.4%vs 96.5%),atrial fibrillation(Afib;58.59%vs 50.5%),coronary artery disease(CAD;11.7%vs 4.4%),dyslipidemia(31.3%vs 39.3%),and having undergone percutaneous coronary intervention(PCI;1.6%vs 0.7%)was higher in the pericardial effusion cohort vs the non-pericardial effusion cohort.Multivariate regression analysis demonstrated that CAD(OR=2.89)and PCI(OR=2.2)had the greatest association with pericardial effusion in patients with LVADs.These were followed by liver disease(OR=1.72),hypothyroidism(OR=1.2),electrolyte derangement(OR=1.2),Afib(OR=1.1),and CKD(OR=1.05).Among patients with LVADs,the median length of stay(33 days vs 27 days)and hospitalization cost(847525 USD vs 792616 USD)were significantly higher in the pericardial effusion cohort compared to the non-pericardial effusion cohort.There was no significant difference in mortality between cohorts.The prevalence of cardiac tamponade was 109(17.9%of LVAD patients with pericardial effusion).Ten(9.2%of LVAD patients with cardiac tamponade)patients underwent pericardiocentesis and 44(40.3%)received a pericardial window.CONCLUSION This study shows that liver disease,CKD,PCI,hypothyroidism,electrolyte derangement,Afib,and CAD had a significant association with pericardial effusion in LVAD patients.Hospitalization cost and length of stay were higher in the pericardial effusion group,but mortality was the same.展开更多
Border Gateway Protocol(BGP),as the standard inter-domain routing protocol,is a distance-vector dynamic routing protocol used for exchanging routing information between distributed Autonomous Systems(AS).BGP nodes,com...Border Gateway Protocol(BGP),as the standard inter-domain routing protocol,is a distance-vector dynamic routing protocol used for exchanging routing information between distributed Autonomous Systems(AS).BGP nodes,communicating in a distributed dynamic environment,face several security challenges,with trust being one of the most important issues in inter-domain routing.Existing research,which performs trust evaluation when exchanging routing information to suppress malicious routing behavior,cannot meet the scalability requirements of BGP nodes.In this paper,we propose a blockchain-based trust model for inter-domain routing.Our model achieves scalability by allowing the master node of an AS alliance to transmit the trust evaluation data of its member nodes to the blockchain.The BGP nodes can expedite the trust evaluation process by accessing a global view of other BGP nodes through the master node of their respective alliance.We incorporate security service evaluation before direct evaluation and indirect recommendations to assess the security services that BGP nodes provide for themselves and prioritize to guarantee their security of routing service.We forward the trust evaluation for neighbor discovery and prioritize the nodes with high trust as neighbor nodes to reduce the malicious exchange routing behavior.We use simulation software to simulate a real BGP environments and employ a comparative experimental research approach to demonstrate the performance evaluation of our trust model.Compared with the classical trust model,our trust model not only saves more storage overhead,but also provides higher security,especially reducing the impact of collusion attacks.展开更多
Lithium-sulfur(Li–S)battery has become one of the most promising next-generation electrical storage systems because of its exceptional energy density of 2600 Wh kg1.However,their commercialization is hindered by seve...Lithium-sulfur(Li–S)battery has become one of the most promising next-generation electrical storage systems because of its exceptional energy density of 2600 Wh kg1.However,their commercialization is hindered by several key obstacles,notably the polysulfide shuttle effect,poor electrical conductance of sulfur,and considerable volumetric change during cycling.This review addresses current advancements in microstructural innovations aimed at improving Li–S battery performance,focusing on modifying cathode materials.The strategies discussed primarily revolve around enhancing the conductivity of sulfur and effectively confining polysulfides to reduce the dissolving of lithium polysulfides in organic electrolytes.Key findings highlight the effectiveness of porous carbon structures and metal compounds in stabilizing polysulfides and enhancing electrochemical performances.Additionally,the roles of advanced synthesis techniques that facilitate the creation of hybrid cathodes with superior mechanical properties and cycling stability are summarized.By addressing the inherent limitations of traditional Li–S battery designs,these innovations pave the way for more efficient and reliable energy storage systems,positioning Li–S technology as a viable alternative to conventional lithium-ion batteries in future applications.展开更多
Data privacy leakage has always been a critical concern in cloud-based Internet of Things(IoT)systems.Dynamic Symmetric Searchable Encryption(DSSE)with forward and backward privacy aims to address this issue by enabli...Data privacy leakage has always been a critical concern in cloud-based Internet of Things(IoT)systems.Dynamic Symmetric Searchable Encryption(DSSE)with forward and backward privacy aims to address this issue by enabling updates and retrievals of ciphertext on untrusted cloud server while ensuring data privacy.However,previous research on DSSE mostly focused on single keyword search,which limits its practical application in cloud-based IoT systems.Recently,Patranabis(NDSS 2021)[1]proposed a groundbreaking DSSE scheme for conjunctive keyword search.However,this scheme fails to effectively handle deletion operations in certain circumstances,resulting in inaccurate query results.Additionally,the scheme introduces unnecessary search overhead.To overcome these problems,we present CKSE,an efficient conjunctive keyword DSSE scheme.Our scheme improves the oblivious shared computation protocol used in the scheme of Patranabis,thus enabling a more comprehensive deletion functionality.Furthermore,we introduce a state chain structure to reduce the search overhead.Through security analysis and experimental evaluation,we demonstrate that our CKSE achieves more comprehensive deletion functionality while maintaining comparable search performance and security,compared to the oblivious dynamic cross-tags protocol of Patranabis.The combination of comprehensive functionality,high efficiency,and security makes our CKSE an ideal choice for deployment in cloud-based IoT systems.展开更多
BACKGROUND Comorbid non-insulin-dependent diabetes mellitus(NIDDM)and stroke sign-ificantly contribute to mortality among older adults.This study examines age-adjusted mortality rates(AAMRs)and disparities by demograp...BACKGROUND Comorbid non-insulin-dependent diabetes mellitus(NIDDM)and stroke sign-ificantly contribute to mortality among older adults.This study examines age-adjusted mortality rates(AAMRs)and disparities by demographics,region,and age groups to identify trends and guide public health efforts.AIM To analyze trends in AAMRs due to comorbid NIDDM and stroke among older adults.The study aims to identify demographic,geographic,and age-related di-sparities to inform targeted public health strategies.METHODS Mortality data from the Centers for Disease Control records were analyzed.AAMRs per 100000 and annual per-centage changes(APCs)with 95%CI were calculated using Joinpoint Regression RESULTS Between 1999 and 2022,209001 deaths among adults aged 55+were attributed to comorbid NIDDM and stroke,with women accounting for 111481 and men 97520 deaths.Urban-rural disparities revealed distinct patterns,with a sharper rise in metropolitan areas post-2014(APC:8.6)as compared to non-metropolitan areas.Racial disparities were pronounced,particularly among the Asian/Pacific Islander population,with a steep increase post-2018(APC:17.6).Age-stratified analysis showed a marked rise in mortality for ages 55-64 and 85+from 2015 onwards(APC:14.3 and 13.5,respectively).Regional trends highlighted the West as having the highest AAMR(14.4),while the Northeast exhibited the lowest(7.0).State-level analysis showed West Virginia with the highest AAMR(18.7)and Nevada the lowest(3.8).CONCLUSION Rising mortality from comorbid NIDDM and stroke underscores increasing disparities across gender,race,age,and regions.Urgent,tailored interventions are required to mitigate these inequities.展开更多
Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transi...Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transition(MIT)region.Rh substitution of Ir is an effective method to induce hole doping into Sr_(3)Ir_(2)O_(7).However,the highest doping level reported in Sr_(3)(Ir_(1-x)Rh_(x))_(2)O_(7)single crystals was only around 3%,which is far from the MIT region.In this paper,we report the successful growth of single crystals of Sr3(Ir_(1-x)Rh_(x))_(2)O_(7)with a doping level of~9%.The samples have been fully characterized,demonstrating the high quality of the single crystals.Transport measurements have been carried out,confirming the tendency of MIT in these samples.The electronic structure has also been examined by angle-resolved photoemission spectroscopy(ARPES)measurements.Our results establish a platform to investigate the heavily hole doped Sr_(3)Ir_(2)O_(7) compound,which also provide new insights into the MIT with hole doping in this material system.展开更多
This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The j...This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The japonica rice was grown in controlled chamber conditions with and without P. formosus LWL1 under no stress （NS） and prolonged heat stress （HS） conditions. Endophytic association under NS and HS conditions significantly improved plant growth attributes, such as plant height, fresh weight, dry weight, and chlorophyll content. Furthermore, P. for- mosus LWL1 protected the rice plants from HS compared with controls, indicated by the lower endogenous level of stress-signaling compounds such as abscisic acid （25.71%） and jasmonic acid （34.57%） and the increase in total protein content （18.76%-33.22%）. Such fungal endophytes may be helpful for sustainable crop production under high environmental temperatures.展开更多
Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the e...Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants（Caralluma acutangula, Rhazya stricta, and Moringa peregrina） and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp.（6 isolates）, Alternaria sp.（2）, Bipolaris sp.（1）, and Cladosporium sp.（1） based on 18 S rD NA sequencing and phylogenetic analysis. The culture filtrates（CFs; 25%, 50%, and 100% concentrations） from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF（100%） of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry（GC/MS） analysis showed the highest indole acetic acid content（（54.31±0.21） μmol/L） in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.展开更多
A triplicate field experiment laid out in randomized complete block design was conducted to evaluate different humic acid (HA) application methods at Agricultural Research Farm, of KPK Agricultural University, Peshawa...A triplicate field experiment laid out in randomized complete block design was conducted to evaluate different humic acid (HA) application methods at Agricultural Research Farm, of KPK Agricultural University, Peshawar. Three methods of HA application: seed priming, foliar spray and soil application were included in the experiment. Humic acid application methods significantly affected pods plant-1, grains pod-1, 1000 grain weights, and grain yield whereas biological yield was not significantly affected by HA application methods. Humic acid application at the rate of 3 kg·ha-1 resulted in higher number of pods plant-1, thousand grain weights and grain yield, however it was statistically similar to the treatments where HA was soil applied at rate of 1 and 2 kg·ha-1, seed priming with 0% (water soaked), 1%, 2% HA solution and foliar spray with 0.01%, 0.05% and 0.1% of HA solution. It is concluded that HA application in all the three methods significantly enhances grain yield and yield components of mungbean.展开更多
Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and he...Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.展开更多
The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of C...The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of CuFe-Co ternary oxides was studied towards the complete catalytic oxidation of CO.The Cu-Fe-Co oxide thin films were deposited on copper grid mesh(CUGM)using one-step pulsed-spray evaporation chemical vapor deposition method.Crystalline structure and morphology analyses revealed nano-crystallite sizes and do me-top-like morphology.Synergistic effects between Cu,Fe and Co,which affect the surface Cu^2+,Fe^3+,Co^3+and chemisorbed oxygen species(O2 and OH)of thin films over the active support and thus result in better reducibility.The thin film catalysts supported on CUGM exhibited attractive catalytic activity compared to the te rnary oxides supported on ine rt grid mesh at a high gas hourly space velocity.Moreove r,the stability in time-on-stream of the ternary oxides on CUGM was evaluated in the CO oxidation for 30 h.The ad opted deposition strategy ofternary oxides on CUGM presents an excessive amount of adsorbed active oxygen species that play an impo rtant role in the complete CO oxidation.The catalysts supported on CUGM showed better catalytic conve rsion than that on inert grid mesh and some literature-reported noble metal oxides as well as transition metal oxides counterparts,revealing the beneficial effect of the CUGM suppo rt in the improvement of the catalytic performance.展开更多
Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services t...Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services to end-users.However,in fog computing(FC),attackers can behave as real fog nodes or end-users to provide malicious services in the network.The attacker acts as an impersonator to impersonate other legitimate users.Therefore,in this work,we present a detection technique to secure the FC environment.First,we model a physical layer key generation based on wireless channel characteristics.To generate the secret keys between the legitimate users and avoid impersonators,we then consider a Double Sarsa technique to identify the impersonators at the receiver end.We compare our proposed Double Sarsa technique with the other two methods to validate our work,i.e.,Sarsa and Q-learning.The simulation results demonstrate that the method based on Double Sarsa outperforms Sarsa and Q-learning approaches in terms of false alarm rate(FAR),miss detection rate(MDR),and average error rate(AER).展开更多
The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in cent...The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in central and peripheral lead-lead(Pb–Pb)and pp collisions at the Large Hadron Collider,are analyzed by the multi-component standard(Boltzmann–Gibbs,Fermi–Dirac,and Bose–Einstein)distributions.The obtained results from the standard distribution give an approximate agreement with the measured experimental data by the STAR,PHENIX,and ALICE Collaborations.The behavior of the effective(kinetic freeze-out)temperature,transverse flow velocity,and kinetic freeze-out volume for particles with different masses is obtained,which observes the early kinetic freezeout of heavier particles as compared to the lighter particles.The parameters of emissions of different particles are observed to be different,which reveals a direct signature of the mass-dependent differential kinetic freeze-out.It is also observed that the peripheral nucleus–nucleus(AA)and pp collisions at the same center-of-mass energy per nucleon pair are in good agreement in terms of the extracted parameters.展开更多
Security threats to smart and autonomous vehicles cause potential consequences such as traffic accidents,economically damaging traffic jams,hijacking,motivating to wrong routes,and financial losses for businesses and ...Security threats to smart and autonomous vehicles cause potential consequences such as traffic accidents,economically damaging traffic jams,hijacking,motivating to wrong routes,and financial losses for businesses and governments.Smart and autonomous vehicles are connected wirelessly,which are more attracted for attackers due to the open nature of wireless communication.One of the problems is the rogue attack,in which the attacker pretends to be a legitimate user or access point by utilizing fake identity.To figure out the problem of a rogue attack,we propose a reinforcement learning algorithm to identify rogue nodes by exploiting the channel state information of the communication link.We consider the communication link between vehicle-to-vehicle,and vehicle-to-infrastructure.We evaluate the performance of our proposed technique by measuring the rogue attack probability,false alarm rate(FAR),mis-detection rate(MDR),and utility function of a receiver based on the test threshold values of reinforcement learning algorithm.The results show that the FAR and MDR are decreased significantly by selecting an appropriate threshold value in order to improve the receiver’s utility.展开更多
We studied the effects of hardwood-derived biochar（BC） and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean（Glycine max（L.） Merr.） with respect to basic, macro- and micronutrient upta...We studied the effects of hardwood-derived biochar（BC） and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean（Glycine max（L.） Merr.） with respect to basic, macro- and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl（DPPH）-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC＋G. geotrichum-treated soybean plants. In comparison, the uptakes of macro- and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC＋G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents.展开更多
Cyber-physical wireless systems have surfaced as an important data communication and networking research area.It is an emerging discipline that allows effective monitoring and efficient real-time communication between...Cyber-physical wireless systems have surfaced as an important data communication and networking research area.It is an emerging discipline that allows effective monitoring and efficient real-time communication between the cyber and physical worlds by embedding computer software and integrating communication and networking technologies.Due to their high reliability,sensitivity and connectivity,their security requirements are more comparable to the Internet as they are prone to various security threats such as eavesdropping,spoofing,botnets,man-in-the-middle attack,denial of service(DoS)and distributed denial of service(DDoS)and impersonation.Existing methods use physical layer authentication(PLA),themost promising solution to detect cyber-attacks.Still,the cyber-physical systems(CPS)have relatively large computational requirements and require more communication resources,thus making it impossible to achieve a low latency target.These methods perform well but only in stationary scenarios.We have extracted the relevant features from the channel matrices using discrete wavelet transformation to improve the computational time required for data processing by considering mobile scenarios.The features are fed to ensemble learning algorithms,such as AdaBoost,LogitBoost and Gentle Boost,to classify data.The authentication of the received signal is considered a binary classification problem.The transmitted data is labeled as legitimate information,and spoofing data is illegitimate information.Therefore,this paper proposes a threshold-free PLA approach that uses machine learning algorithms to protect critical data from spoofing attacks.It detects the malicious data packets in stationary scenarios and detects them with high accuracy when receivers are mobile.The proposed model achieves better performance than the existing approaches in terms of accuracy and computational time by decreasing the processing time.展开更多
Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wirele...Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.展开更多
Non-Orthogonal Multiple Access(NOMA)has already proven to be an effective multiple access scheme for5th Generation(5G)wireless networks.It provides improved performance in terms of system throughput,spectral efficienc...Non-Orthogonal Multiple Access(NOMA)has already proven to be an effective multiple access scheme for5th Generation(5G)wireless networks.It provides improved performance in terms of system throughput,spectral efficiency,fairness,and energy efficiency(EE).However,in conventional NOMA networks,performance degradation still exists because of the stochastic behavior of wireless channels.To combat this challenge,the concept of Intelligent Reflecting Surface(IRS)has risen to prominence as a low-cost intelligent solution for Beyond 5G(B5G)networks.In this paper,a modeling primer based on the integration of these two cutting-edge technologies,i.e.,IRS and NOMA,for B5G wireless networks is presented.An in-depth comparative analysis of IRS-assisted Power Domain(PD)-NOMA networks is provided through 3-fold investigations.First,a primer is presented on the system architecture of IRS-enabled multiple-configuration PD-NOMA systems,and parallels are drawn with conventional network configurations,i.e.,conventional NOMA,Orthogonal Multiple Access(OMA),and IRS-assisted OMA networks.Followed by this,a comparative analysis of these network configurations is showcased in terms of significant performance metrics,namely,individual users'achievable rate,sum rate,ergodic rate,EE,and outage probability.Moreover,for multi-antenna IRS-enabled NOMA networks,we exploit the active Beamforming(BF)technique by employing a greedy algorithm using a state-of-the-art branch-reduceand-bound(BRB)method.The optimality of the BRB algorithm is presented by comparing it with benchmark BF techniques,i.e.,minimum-mean-square-error,zero-forcing-BF,and maximum-ratio-transmission.Furthermore,we present an outlook on future envisioned NOMA networks,aided by IRSs,i.e.,with a variety of potential applications for 6G wireless networks.This work presents a generic performance assessment toolkit for wireless networks,focusing on IRS-assisted NOMA networks.This comparative analysis provides a solid foundation for the development of future IRS-enabled,energy-efficient wireless communication systems.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12074358)the National Key Research and Development Program of China(Grant No.2024YFA1408103)+2 种基金the International Partnership Program of the Chinese Academy of Sciences(Grant No.123GJHZ2022035MI)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)the Fundamental Research Funds for the Central Universities(Grant No.WK3510000015)。
文摘Metal-insulator transition(MIT)in perovskite iridium oxides Sr_(n+1)IrnO_(3n+1)represents one of the most attractive phenomena exemplifying the cooperation of Coulomb interaction and spin-orbit coupling(SOC).MIT takes place when Sr_(n+1)IrnO_(3n+1)(n=1,2)is doped with carriers.While electron-doped Sr_(n+1)IrnO_(3n+1)(n=1,2)systems have been extensively investigated,hole-doped samples are still limited.Here,we report the first growth of Fe-doped(hole-doped)Sr_(3)Ir_(2)O_(7)single crystals[Sr_3(Ir_(1-x)Fe_x)_(2)O_(7)]with the doping level 0.1≤x≤0.28.An MIT behavior is observed at the doping level of x~0.16 from resistivity measurements.Electronic structures of Fe-doped Sr_(3)Ir_(2)O_(7)have been revealed by angle-resolved photoemission spectroscopy(ARPES)measurements.The evident energy shift of the band structure indicates higher hole-doping level as compared with Rh-doped Sr_(3)Ir_(2)O_(7).Our results demonstrate that Fe doping serves as an effective approach for heavily hole doping in Sr_(3)Ir_(2)O_(7),thereby offering a powerful strategy to modulate MIT in this material system.
文摘Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.
文摘BACKGROUND Development of pericardial effusion in patients with left ventricular assist devices(LVADs)can be detrimental to health outcomes.This study aims to elucidate the prevalence and risk factors for pericardial effusion in patients with LVADs.AIM To elucidate risk factors associated with the presence of pericardial effusion in patients with LVADs and compare the clinical outcomes of those with and without pericardial effusion.The secondary goal is to determine the incidence of pericardiocentesis and pericardial window placement in patients with LVADs experiencing pericardial effusion.METHODS Data were obtained from the National Inpatient Sample database between 2016 and 2018.Statistical analysis was performed using Pearsonχ2 test and multivariate logistic regression analysis to determine clinical outcomes of pericardial effusion and to identify variables associated with pericardial effusion in LVAD patients,respectively.RESULTS The prevalence of LVAD was 9850(0.01%)among total study patients(n=98112095).The incidence of pericardial effusion among LVAD patients was 640(6.5%).The prevalence of liver disease(26.6%vs 17.4%),chronic kidney disease(CKD;54.6%vs 49.4%),hypothyroidism(21.9%vs 18.1%),congestive heart failure(98.4%vs 96.5%),atrial fibrillation(Afib;58.59%vs 50.5%),coronary artery disease(CAD;11.7%vs 4.4%),dyslipidemia(31.3%vs 39.3%),and having undergone percutaneous coronary intervention(PCI;1.6%vs 0.7%)was higher in the pericardial effusion cohort vs the non-pericardial effusion cohort.Multivariate regression analysis demonstrated that CAD(OR=2.89)and PCI(OR=2.2)had the greatest association with pericardial effusion in patients with LVADs.These were followed by liver disease(OR=1.72),hypothyroidism(OR=1.2),electrolyte derangement(OR=1.2),Afib(OR=1.1),and CKD(OR=1.05).Among patients with LVADs,the median length of stay(33 days vs 27 days)and hospitalization cost(847525 USD vs 792616 USD)were significantly higher in the pericardial effusion cohort compared to the non-pericardial effusion cohort.There was no significant difference in mortality between cohorts.The prevalence of cardiac tamponade was 109(17.9%of LVAD patients with pericardial effusion).Ten(9.2%of LVAD patients with cardiac tamponade)patients underwent pericardiocentesis and 44(40.3%)received a pericardial window.CONCLUSION This study shows that liver disease,CKD,PCI,hypothyroidism,electrolyte derangement,Afib,and CAD had a significant association with pericardial effusion in LVAD patients.Hospitalization cost and length of stay were higher in the pericardial effusion group,but mortality was the same.
基金funded by the National Natural Science Foundation of China,grant numbers(62272007,62001007)the Natural Science Foundation of Beijing,grant numbers(4234083,4212018)The authors also extend their appreciation to King Khalid University for funding this work through the Large Group Project under grant number RGP.2/373/45.
文摘Border Gateway Protocol(BGP),as the standard inter-domain routing protocol,is a distance-vector dynamic routing protocol used for exchanging routing information between distributed Autonomous Systems(AS).BGP nodes,communicating in a distributed dynamic environment,face several security challenges,with trust being one of the most important issues in inter-domain routing.Existing research,which performs trust evaluation when exchanging routing information to suppress malicious routing behavior,cannot meet the scalability requirements of BGP nodes.In this paper,we propose a blockchain-based trust model for inter-domain routing.Our model achieves scalability by allowing the master node of an AS alliance to transmit the trust evaluation data of its member nodes to the blockchain.The BGP nodes can expedite the trust evaluation process by accessing a global view of other BGP nodes through the master node of their respective alliance.We incorporate security service evaluation before direct evaluation and indirect recommendations to assess the security services that BGP nodes provide for themselves and prioritize to guarantee their security of routing service.We forward the trust evaluation for neighbor discovery and prioritize the nodes with high trust as neighbor nodes to reduce the malicious exchange routing behavior.We use simulation software to simulate a real BGP environments and employ a comparative experimental research approach to demonstrate the performance evaluation of our trust model.Compared with the classical trust model,our trust model not only saves more storage overhead,but also provides higher security,especially reducing the impact of collusion attacks.
基金Songshan Lake Materials Laboratory(2022SLABFN26)National Natural Science Foundation of China(21773024).
文摘Lithium-sulfur(Li–S)battery has become one of the most promising next-generation electrical storage systems because of its exceptional energy density of 2600 Wh kg1.However,their commercialization is hindered by several key obstacles,notably the polysulfide shuttle effect,poor electrical conductance of sulfur,and considerable volumetric change during cycling.This review addresses current advancements in microstructural innovations aimed at improving Li–S battery performance,focusing on modifying cathode materials.The strategies discussed primarily revolve around enhancing the conductivity of sulfur and effectively confining polysulfides to reduce the dissolving of lithium polysulfides in organic electrolytes.Key findings highlight the effectiveness of porous carbon structures and metal compounds in stabilizing polysulfides and enhancing electrochemical performances.Additionally,the roles of advanced synthesis techniques that facilitate the creation of hybrid cathodes with superior mechanical properties and cycling stability are summarized.By addressing the inherent limitations of traditional Li–S battery designs,these innovations pave the way for more efficient and reliable energy storage systems,positioning Li–S technology as a viable alternative to conventional lithium-ion batteries in future applications.
基金supported in part by the Major Science and Technology Projects in Yunnan Province(202202AD080013)King Khalid University for funding this work through Large Group Project under grant number RGP.2/373/45.
文摘Data privacy leakage has always been a critical concern in cloud-based Internet of Things(IoT)systems.Dynamic Symmetric Searchable Encryption(DSSE)with forward and backward privacy aims to address this issue by enabling updates and retrievals of ciphertext on untrusted cloud server while ensuring data privacy.However,previous research on DSSE mostly focused on single keyword search,which limits its practical application in cloud-based IoT systems.Recently,Patranabis(NDSS 2021)[1]proposed a groundbreaking DSSE scheme for conjunctive keyword search.However,this scheme fails to effectively handle deletion operations in certain circumstances,resulting in inaccurate query results.Additionally,the scheme introduces unnecessary search overhead.To overcome these problems,we present CKSE,an efficient conjunctive keyword DSSE scheme.Our scheme improves the oblivious shared computation protocol used in the scheme of Patranabis,thus enabling a more comprehensive deletion functionality.Furthermore,we introduce a state chain structure to reduce the search overhead.Through security analysis and experimental evaluation,we demonstrate that our CKSE achieves more comprehensive deletion functionality while maintaining comparable search performance and security,compared to the oblivious dynamic cross-tags protocol of Patranabis.The combination of comprehensive functionality,high efficiency,and security makes our CKSE an ideal choice for deployment in cloud-based IoT systems.
文摘BACKGROUND Comorbid non-insulin-dependent diabetes mellitus(NIDDM)and stroke sign-ificantly contribute to mortality among older adults.This study examines age-adjusted mortality rates(AAMRs)and disparities by demographics,region,and age groups to identify trends and guide public health efforts.AIM To analyze trends in AAMRs due to comorbid NIDDM and stroke among older adults.The study aims to identify demographic,geographic,and age-related di-sparities to inform targeted public health strategies.METHODS Mortality data from the Centers for Disease Control records were analyzed.AAMRs per 100000 and annual per-centage changes(APCs)with 95%CI were calculated using Joinpoint Regression RESULTS Between 1999 and 2022,209001 deaths among adults aged 55+were attributed to comorbid NIDDM and stroke,with women accounting for 111481 and men 97520 deaths.Urban-rural disparities revealed distinct patterns,with a sharper rise in metropolitan areas post-2014(APC:8.6)as compared to non-metropolitan areas.Racial disparities were pronounced,particularly among the Asian/Pacific Islander population,with a steep increase post-2018(APC:17.6).Age-stratified analysis showed a marked rise in mortality for ages 55-64 and 85+from 2015 onwards(APC:14.3 and 13.5,respectively).Regional trends highlighted the West as having the highest AAMR(14.4),while the Northeast exhibited the lowest(7.0).State-level analysis showed West Virginia with the highest AAMR(18.7)and Nevada the lowest(3.8).CONCLUSION Rising mortality from comorbid NIDDM and stroke underscores increasing disparities across gender,race,age,and regions.Urgent,tailored interventions are required to mitigate these inequities.
基金supported by the USTC start-up fundthe National Natural Science Foundation of China(Grant Nos.12074358 and 12004363)+2 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.WK3510000008 and WK2030000035)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302802)supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences under Contract No.DEAC02-76SF00515。
文摘Ruddlesden-Popper iridate Sr_(3)Ir_(2)O_(7)is a spin-orbit coupled Mott insulator.Hole doped Sr_(3)Ir_(2)O_(7)provides an ideal platform to study the exotic quantum phenomena that occur near the metal-insulator transition(MIT)region.Rh substitution of Ir is an effective method to induce hole doping into Sr_(3)Ir_(2)O_(7).However,the highest doping level reported in Sr_(3)(Ir_(1-x)Rh_(x))_(2)O_(7)single crystals was only around 3%,which is far from the MIT region.In this paper,we report the successful growth of single crystals of Sr3(Ir_(1-x)Rh_(x))_(2)O_(7)with a doping level of~9%.The samples have been fully characterized,demonstrating the high quality of the single crystals.Transport measurements have been carried out,confirming the tendency of MIT in these samples.The electronic structure has also been examined by angle-resolved photoemission spectroscopy(ARPES)measurements.Our results establish a platform to investigate the heavily hole doped Sr_(3)Ir_(2)O_(7) compound,which also provide new insights into the MIT with hole doping in this material system.
基金supported by the National Research Foundation of Korea(NRF)Ministry of Science,ICT and Future-Planning through Basic-Science Research Program(No.2014R1A1A2A10058022)
文摘This study identifies the potential role in heat-stress mitigation of phytohormones and other secondary metabolites produced by the endophytic fungus Paecilomyces formosus LWL1 in japonica rice cultivar Dongjin. The japonica rice was grown in controlled chamber conditions with and without P. formosus LWL1 under no stress （NS） and prolonged heat stress （HS） conditions. Endophytic association under NS and HS conditions significantly improved plant growth attributes, such as plant height, fresh weight, dry weight, and chlorophyll content. Furthermore, P. for- mosus LWL1 protected the rice plants from HS compared with controls, indicated by the lower endogenous level of stress-signaling compounds such as abscisic acid （25.71%） and jasmonic acid （34.57%） and the increase in total protein content （18.76%-33.22%）. Such fungal endophytes may be helpful for sustainable crop production under high environmental temperatures.
基金Project supported by the Oman Research Council(FURAP Program)the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture,Forestry and Fisheries(IPET) through Agriculture,Food and Rural Affairs Research Center Support Program,funded by Ministry of Agriculture,Food and Rural Affairs(MAFRA)(716001-7)
文摘Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants（Caralluma acutangula, Rhazya stricta, and Moringa peregrina） and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp.（6 isolates）, Alternaria sp.（2）, Bipolaris sp.（1）, and Cladosporium sp.（1） based on 18 S rD NA sequencing and phylogenetic analysis. The culture filtrates（CFs; 25%, 50%, and 100% concentrations） from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF（100%） of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry（GC/MS） analysis showed the highest indole acetic acid content（（54.31±0.21） μmol/L） in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses.
文摘A triplicate field experiment laid out in randomized complete block design was conducted to evaluate different humic acid (HA) application methods at Agricultural Research Farm, of KPK Agricultural University, Peshawar. Three methods of HA application: seed priming, foliar spray and soil application were included in the experiment. Humic acid application methods significantly affected pods plant-1, grains pod-1, 1000 grain weights, and grain yield whereas biological yield was not significantly affected by HA application methods. Humic acid application at the rate of 3 kg·ha-1 resulted in higher number of pods plant-1, thousand grain weights and grain yield, however it was statistically similar to the treatments where HA was soil applied at rate of 1 and 2 kg·ha-1, seed priming with 0% (water soaked), 1%, 2% HA solution and foliar spray with 0.01%, 0.05% and 0.1% of HA solution. It is concluded that HA application in all the three methods significantly enhances grain yield and yield components of mungbean.
基金This work was supported by the National Research Foundation of Korea(NRF)Grant funded by the Korea government(MSIT)(NRF-2022R1A2C2004771)Internal Research Grant by ORIC,SukkurIBA University 2022.
文摘Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.
基金financial support from the MOST(No.2017YFA0402800)the Basic Science Center Program for Ordered Energy Conversion of the National Natural Science Foundation of China(No.51888103)。
文摘The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great interest.Here,the role of active substrate in the performance and stability of CuFe-Co ternary oxides was studied towards the complete catalytic oxidation of CO.The Cu-Fe-Co oxide thin films were deposited on copper grid mesh(CUGM)using one-step pulsed-spray evaporation chemical vapor deposition method.Crystalline structure and morphology analyses revealed nano-crystallite sizes and do me-top-like morphology.Synergistic effects between Cu,Fe and Co,which affect the surface Cu^2+,Fe^3+,Co^3+and chemisorbed oxygen species(O2 and OH)of thin films over the active support and thus result in better reducibility.The thin film catalysts supported on CUGM exhibited attractive catalytic activity compared to the te rnary oxides supported on ine rt grid mesh at a high gas hourly space velocity.Moreove r,the stability in time-on-stream of the ternary oxides on CUGM was evaluated in the CO oxidation for 30 h.The ad opted deposition strategy ofternary oxides on CUGM presents an excessive amount of adsorbed active oxygen species that play an impo rtant role in the complete CO oxidation.The catalysts supported on CUGM showed better catalytic conve rsion than that on inert grid mesh and some literature-reported noble metal oxides as well as transition metal oxides counterparts,revealing the beneficial effect of the CUGM suppo rt in the improvement of the catalytic performance.
基金supported by Natural Science Foundation of China(61801008)The China National Key R&D Program(No.2018YFB0803600)+1 种基金Scientific Research Common Program of Beijing Municipal Commission of Education(No.KM201910005025)Chinese Postdoctoral Science Foundation(No.2020M670074).
文摘Fog computing paradigm extends computing,communication,storage,and network resources to the network’s edge.As the fog layer is located between cloud and end-users,it can provide more convenience and timely services to end-users.However,in fog computing(FC),attackers can behave as real fog nodes or end-users to provide malicious services in the network.The attacker acts as an impersonator to impersonate other legitimate users.Therefore,in this work,we present a detection technique to secure the FC environment.First,we model a physical layer key generation based on wireless channel characteristics.To generate the secret keys between the legitimate users and avoid impersonators,we then consider a Double Sarsa technique to identify the impersonators at the receiver end.We compare our proposed Double Sarsa technique with the other two methods to validate our work,i.e.,Sarsa and Q-learning.The simulation results demonstrate that the method based on Double Sarsa outperforms Sarsa and Q-learning approaches in terms of false alarm rate(FAR),miss detection rate(MDR),and average error rate(AER).
基金supported by the National Natural Science Foundation of China(Nos.11575103 and 11947418)the Chinese Government Scholarship(China Scholarship Council)+2 种基金the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(STIP)(No.201802017)the Shanxi Provincial Natural Science Foundation(No.201901D111043)the Fund for Shanxi‘‘1331 Project’’Key Subjects Construction。
文摘The transverse momentum spectra of different types of particles produced in central and peripheral gold–gold(Au–Au)and inelastic proton–proton(pp)collisions at the Relativistic Heavy Ion Collider,as well as in central and peripheral lead-lead(Pb–Pb)and pp collisions at the Large Hadron Collider,are analyzed by the multi-component standard(Boltzmann–Gibbs,Fermi–Dirac,and Bose–Einstein)distributions.The obtained results from the standard distribution give an approximate agreement with the measured experimental data by the STAR,PHENIX,and ALICE Collaborations.The behavior of the effective(kinetic freeze-out)temperature,transverse flow velocity,and kinetic freeze-out volume for particles with different masses is obtained,which observes the early kinetic freezeout of heavier particles as compared to the lighter particles.The parameters of emissions of different particles are observed to be different,which reveals a direct signature of the mass-dependent differential kinetic freeze-out.It is also observed that the peripheral nucleus–nucleus(AA)and pp collisions at the same center-of-mass energy per nucleon pair are in good agreement in terms of the extracted parameters.
基金This work was partially supported by The China’s National Key R&D Program(No.2018YFB0803600)Natural Science Foundation of China(No.61801008)+2 种基金Beijing Natural Science Foundation National(No.L172049)Scientific Research Common Program of Beijing Municipal Commission of Education(No.KM201910005025)Defense Industrial Technology Development Program(No.JCKY2016204A102)sponsored this research in parts.
文摘Security threats to smart and autonomous vehicles cause potential consequences such as traffic accidents,economically damaging traffic jams,hijacking,motivating to wrong routes,and financial losses for businesses and governments.Smart and autonomous vehicles are connected wirelessly,which are more attracted for attackers due to the open nature of wireless communication.One of the problems is the rogue attack,in which the attacker pretends to be a legitimate user or access point by utilizing fake identity.To figure out the problem of a rogue attack,we propose a reinforcement learning algorithm to identify rogue nodes by exploiting the channel state information of the communication link.We consider the communication link between vehicle-to-vehicle,and vehicle-to-infrastructure.We evaluate the performance of our proposed technique by measuring the rogue attack probability,false alarm rate(FAR),mis-detection rate(MDR),and utility function of a receiver based on the test threshold values of reinforcement learning algorithm.The results show that the FAR and MDR are decreased significantly by selecting an appropriate threshold value in order to improve the receiver’s utility.
基金Project supported by the Korea Institute of Planning and Evaluation for Technology in Food,Agriculture,Forestry and Fisheries(IPET) through Agriculture,Food and Rural Affairs Research Center Support Program,funded by Ministry of Agriculture,Food and Rural Affairs(MAFRA)(716001-7)
文摘We studied the effects of hardwood-derived biochar（BC） and the phytohormone-producing endophyte Galactomyces geotrichum WLL1 in soybean（Glycine max（L.） Merr.） with respect to basic, macro- and micronutrient uptakes and assimilations, and their subsequent effects on the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and 1,1-diphenyl-2-picrylhydrazyl（DPPH）-scavenging activity. The assimilation of basic nutrients such as nitrogen was up-regulated, leaving carbon, oxygen, and hydrogen unaffected in BC＋G. geotrichum-treated soybean plants. In comparison, the uptakes of macro- and micronutrients fluctuated in the individual or co-application of BC and G. geotrichum in soybean plant organs and rhizospheric substrate. Moreover, the same attribute was recorded for the regulation of functional amino acids, isoflavones, fatty acid composition, total sugar contents, total phenolic contents, and DPPH-scavenging activity. Collectively, these results showed that BC＋G. geotrichum-treated soybean yielded better results than did the plants treated with individual applications. It was concluded that BC is an additional nutriment source and that the G. geotrichum acts as a plant biostimulating source and the effects of both are additive towards plant growth promotion. Strategies involving the incorporation of BC and endophytic symbiosis may help achieve eco-friendly agricultural production, thus reducing the excessive use of chemical agents.
基金This work is supported in part by the Beijing Natural Science Foundation(No.4212015)Natural Science Foundation of China(No.61801008)+3 种基金China Ministry of Education-China Mobile Scientific Research Foundation(No.MCM20200102)China Postdoctoral Science Foundation(No.2020M670074)Beijing Municipal Commission of Education Foundation(No.KM201910005025)Beijing Postdoctoral Research Foundation(No.2021-ZZ-077,No.2020-YJ-006).
文摘Cyber-physical wireless systems have surfaced as an important data communication and networking research area.It is an emerging discipline that allows effective monitoring and efficient real-time communication between the cyber and physical worlds by embedding computer software and integrating communication and networking technologies.Due to their high reliability,sensitivity and connectivity,their security requirements are more comparable to the Internet as they are prone to various security threats such as eavesdropping,spoofing,botnets,man-in-the-middle attack,denial of service(DoS)and distributed denial of service(DDoS)and impersonation.Existing methods use physical layer authentication(PLA),themost promising solution to detect cyber-attacks.Still,the cyber-physical systems(CPS)have relatively large computational requirements and require more communication resources,thus making it impossible to achieve a low latency target.These methods perform well but only in stationary scenarios.We have extracted the relevant features from the channel matrices using discrete wavelet transformation to improve the computational time required for data processing by considering mobile scenarios.The features are fed to ensemble learning algorithms,such as AdaBoost,LogitBoost and Gentle Boost,to classify data.The authentication of the received signal is considered a binary classification problem.The transmitted data is labeled as legitimate information,and spoofing data is illegitimate information.Therefore,this paper proposes a threshold-free PLA approach that uses machine learning algorithms to protect critical data from spoofing attacks.It detects the malicious data packets in stationary scenarios and detects them with high accuracy when receivers are mobile.The proposed model achieves better performance than the existing approaches in terms of accuracy and computational time by decreasing the processing time.
基金supported by the China National Key R&D Program(No.2018YFB0803600)Natural Science Foundation of China(No.61801008)+3 种基金Scientific Research Common Program of Beijing Municipal Education Commission(No.KM201910005025)the Chinese Postdoctoral Science Foundation(No.2020M670074)Key Project of Hunan Provincial,Department of Education(No.26420A205)The Construct Program of Applied Characteristics Discipline in Hunan University of Science and Engineering.
文摘Secret key generation(SKG)is an emerging technology to secure wireless communication from attackers.Therefore,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’uncertainty.However,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power allocation.The coherence time for PHY-SKG is not applicable to secure wireless channels.This is because coherence time is for a certain period of time.Thus,legitimate users generate the secret keys(SKs)with a shorter key length in size.Hence,an attacker can quickly get information about the SKs.Consequently,the attacker can easily get valuable information from authentic users.Therefore,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate users.Hence,we propose an alternative method,i.e.,a power allocation,to improve the SKGR.Our results show 72%higher SKGR in bits/sec by increasing power transmission.In addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission equations.We found out that a higher value of epsilon impacts power transmission and subsequently impacts the SKGR.The SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=1.The value of SKGR is reduced to 18.5%at 250 mW when epsilonis 0.5.Furthermore,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=0.5.Hence,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.
基金supported by Higher Education Commission(HEC)of Pakistan through its National Research Program for Universities(NRPU)[Ref.No.20-14560/NRPU/R&D/HEC/2021]support provided by HEC。
文摘Non-Orthogonal Multiple Access(NOMA)has already proven to be an effective multiple access scheme for5th Generation(5G)wireless networks.It provides improved performance in terms of system throughput,spectral efficiency,fairness,and energy efficiency(EE).However,in conventional NOMA networks,performance degradation still exists because of the stochastic behavior of wireless channels.To combat this challenge,the concept of Intelligent Reflecting Surface(IRS)has risen to prominence as a low-cost intelligent solution for Beyond 5G(B5G)networks.In this paper,a modeling primer based on the integration of these two cutting-edge technologies,i.e.,IRS and NOMA,for B5G wireless networks is presented.An in-depth comparative analysis of IRS-assisted Power Domain(PD)-NOMA networks is provided through 3-fold investigations.First,a primer is presented on the system architecture of IRS-enabled multiple-configuration PD-NOMA systems,and parallels are drawn with conventional network configurations,i.e.,conventional NOMA,Orthogonal Multiple Access(OMA),and IRS-assisted OMA networks.Followed by this,a comparative analysis of these network configurations is showcased in terms of significant performance metrics,namely,individual users'achievable rate,sum rate,ergodic rate,EE,and outage probability.Moreover,for multi-antenna IRS-enabled NOMA networks,we exploit the active Beamforming(BF)technique by employing a greedy algorithm using a state-of-the-art branch-reduceand-bound(BRB)method.The optimality of the BRB algorithm is presented by comparing it with benchmark BF techniques,i.e.,minimum-mean-square-error,zero-forcing-BF,and maximum-ratio-transmission.Furthermore,we present an outlook on future envisioned NOMA networks,aided by IRSs,i.e.,with a variety of potential applications for 6G wireless networks.This work presents a generic performance assessment toolkit for wireless networks,focusing on IRS-assisted NOMA networks.This comparative analysis provides a solid foundation for the development of future IRS-enabled,energy-efficient wireless communication systems.
