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Decentralized Dynamic Event-Triggered Communication and Active Suspension Control of In-Wheel Motor Driven Electric Vehicles with Dynamic Damping

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IEEE/CAA Journal of Automatica Sinica 2021年第5期8卷 971-986页

作者： iftikhar ahmad Xiaohua Ge Qing-Long Han the School of Software and Electrical Engineering Swinburne University of TechnologyMelbourneVIC 3122Australia

This paper addresses the co-design problem of decentralized dynamic event-triggered communication and active suspension control for an in-wheel motor driven electric vehicle equipped with a dynamic damper. The main objective is to simultaneously improve the desired suspension performance caused by various road disturbances and alleviate the network resource utilization for the concerned in-vehicle networked suspension system. First, a T-S fuzzy active suspension model of an electric vehicle under dynamic damping is established. Second,a novel decentralized dynamic event-triggered communication mechanism is developed to regulate each sensor's data transmissions such that sampled data packets on each sensor are scheduled in an independent manner. In contrast to the traditional static triggering mechanisms, a key feature of the proposed mechanism is that the threshold parameter in the event trigger is adjusted adaptively over time to reduce the network resources occupancy. Third, co-design criteria for the desired event-triggered fuzzy controller and dynamic triggering mechanisms are derived. Finally, comprehensive comparative simulation studies of a 3-degrees-of-freedom quarter suspension model are provided under both bump road disturbance and ISO-2631 classified random road disturbance to validate the effectiveness of the proposed co-design approach. It is shown that ride comfort can be greatly improved in either road disturbance case and the suspension deflection, dynamic tyre load and actuator control input are all kept below the prescribed maximum allowable limits, while simultaneously maintaining desirable communication efficiency.

关键词： Active suspension control decentralized eventtriggered control dynamic damper dynamic eventtriggered communication in-wheel motor driven electric vehicle

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Towards Improving the Intrusion Detection through ELM (Extreme Learning Machine)

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Computers, Materials & Continua 2020年第11期65卷 1097-1111页

作者： iftikhar ahmad Rayan Atteah Alsemmeari D.I.T Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia

An IDS(intrusion detection system)provides a foremost front line mechanism to guard networks,systems,data,and ***’s why intrusion detection has grown as an active study area and provides significant contribution to cyber-security *** techniques have been in use but major concern in their implementation is variation in their detection *** performance of IDS lies in the accurate detection of attacks,and this accuracy can be raised by improving the recognition rate and significant reduction in the false alarms *** overcome this problem many researchers have used different machine learning *** techniques have limitations and do not efficiently perform on huge and complex data about systems and *** work focused on ELM(Extreme Learning Machine)technique due to its good capabilities in classification problems and dealing with huge *** ELM has different activation functions,but the problem is to find out which function is more suitable and performs well in *** work investigates this ***,Well-known activation functions like:sine,sigmoid and radial basis are explored,investigated and applied to measure their performance on the GA(Genetic Algorithm)features subset and with full features *** NSL-KDD dataset is used as a *** empirical results are analyzed,addressed and compared among different activation functions of the *** results show that the radial basis and sine functions perform better on GA feature set than the full feature set while the performance of the sigmoid function is almost equal on both features ***,the proposal of GA based feature selection reduced 21 features out of 41 that brought up to 98%accuracy and enhanced overall efficiency of extreme learning machine in intrusion detection.

关键词： Accuracy extreme learning machine sine function sigmoid function radial basis genetic algorithm NSL-KDD

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Control of Group Velocity via Spontaneous Generated Coherence and Kerr Nonlinearity

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Communications in Theoretical Physics 2014年第9期61卷 410-416页

作者： Hazrat Ali iftikhar ahmad Ziauddin Department of Physics University of Malakand Khyber Pakhtunkhwa Pakistan Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan Institute of Photonics Technologies National Tsing Hua University

A four-level N-type atomic medium is considered to study the effect of spontaneous generated coherence(SGC) and Kerr nonlinearity on light pulse propagation. A light pulse is propagating inside the medium where each atom follows four-level N-type atom-field configuration of rubidium(85Rb) atom. The atom-field interaction leads to electromagnetically induced transparency(EIT) process. The atom-field interaction is accompanied by normal dispersion and in the presence of SGC and Kerr nonlinearity the dispersion property of the proposed atomic medium is modified,which leads to enhancement of positive group index of the medium. The enhancement of positive group index then leads to slow group velocity inside the medium. A more slow group velocity is also investigated by incorporated the collective effect of SGC and Kerr nonlinearity. The control of group velocity inside a four-level N-type atomic medium via collective effect of SGC and Kerr nonlinearity is the major part of this work.

关键词： Kerr nonlinearity spontaneous generated coherence and group index

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Distributed Modeling of Extraterrestrial Solar Radiation Over the Rugged Terrains of Pakistan

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Journal of Mountain Science 2011年第3期8卷 427-436页

作者： Romana AMBREEN QIU Xinfa iftikhar ahmad Key laboratory of Meteorological Disaster of Ministry of Education Nanjing University of Information Science & Technology Nanjing 210044 China Department of Geography University of Balochistan Quetta Pakistan

In Pakistan,the solar analogue has been addressed but its surface geographical parameterization has given least *** density of stations and their spatial coverage particularly in difficult peripheral national territories,little or no solar radiation data,non-satisfactory sunshine hours data,and low quality of ground observed cloud cover data create a situation in which the spatial modeling of Extraterrestrial Solar Radiation(ESR) and its ground parameterization got sufficient *** Digital Elevation Model (DEM) input into Geographic Information System (GIS) is a compatible tool to demonstrate the spatial distribution of ESR over the rugged terrains of the study *** the first time,distributed modeling of ESR is done over the rugged terrains of Pakistan,based on DEM and ArcGIS..Results clearly depict that the complex landforms profoundly disrupt the zonal distribution of ESR in *** screening impact of topography is higher on spatial distribution of ESR in winter and considerably low in *** combined effect of topography and latitude is ***,the model was further testified by plotting Rb (ratio of ESR quantity over rugged terrain against plane surface) against azimuth at different latitudes with different angled *** results clearly support the strong screening effect of rugged terrain through out the country especially in Himalayas,Karakoram and Hindukush (HKH),western border mountains and Balochistan *** model can be instrumental as baseline geospatial information for scientific investigations in Pakistan,where substantial fraction of national population is living in mountainous regions.

关键词： Pakistan distributed modeling ESR DEM GIS rugged terrain

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Journal of Rare Earths 2018年第10期36卷 1106-1111页

作者： Sardar ahmad M.Shafiq Rashid ahmad S.Jalali-Asadabadi iftikhar ahmad Department of Chemistry University of Malakand Center for Computational Materials Science University of Malakand Department of Physics Abbottabad University of Science and Technology Department of Physics Faculty of SciencesUniversity of Isfahan

In this paper, we explored the structural, elastic and mechanical properties of the strongly correlated electron systems, intermetallic Ln-Au（Ln = Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu） in cubic structure,using PF-LAPW method within the density functional theory. Structural properties of these intermetallics were investigated by treating the exchange-correlation potential with the GGA-PBE, GGA-PBEsol and GGA ＋ U. The effectiveness of the U for the structural properties as compared to other methods confirms the strong correlated nature of these compounds and the calculated lattice constants endorse the divalency of Yb. The results demonstrate the stable cubic CsCl structure of these compounds. Bulk modulus, Young＇s modulus, shear modulus, B/G ratio, Cauchy pressure, Poisson＇s ratio, anisotropic ratio,Kleinman parameters and Lame＇s coefficients were studied using the PBEsol to evaluate their importance in various types of engineering applications. The most prominent features of these compounds are their ductility, very high melting points, resistance to corrosion, and anisotropic nature.

关键词： Strongly correlated electron systems Rare-earth monoaurides Mechanical properties Ab-initio calculation

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Hot-pressed graphene nanoplatelets or/and zirconia reinforced hybrid alumina nanocomposites with improved toughness and mechanical characteristics

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Journal of Materials Science & Technology 2020年第5期40卷 135-145页

作者： iftikhar ahmad Mohammad Islam Nuha Al Habis Shahid Parvez Center of Excellence for Research in Engineering Materials Deanship of Scientific ResearchKing Saud UniversityP.O.Box 800Riyadh 11421Saudi Arabia Mechanical Engineering Department College of EngineeringKing Saud UniversityP.O.Box 800Riyadh 11421Saudi Arabia

This work explains the synergistic contribution of graphene nanoplatelets(GNP)and zirconia ceramic nanoparticles(ZrO2)on the microstructure,mechanical performance and ballistic properties of the alumina(Al2O3)ceramic hybrid *** the benchmarked monolithic alumina,the hotpressed hybrid nanocomposite microstructure demonstrated 68%lower grain size due to grain pinning phenomenon by the homogenously distributed reinforcing GNP(0.5 wt%)and zirconia(4 wt%)***,the hybrid nanocomposite manifested 155%better fracture toughness(KIC)and 17%higher microhardness as well as 88%superior ballistic trait over the monolithic alumina,*** superior mechanical and ballistic performance of the hybrid nanocomposites was attributed to the combined role of zirconia nanoparticles and GNP nanomaterial in refining the microstructure and inducing idiosyncratic strengthening/toughening *** combined electron microscopy revealed complicated physical interlocking of the GNP into the microstructure as well as excellent bonding of the GNP with alumina at their interface in the hybrid *** also probed the efficiency of the pull-out and crack-bridging toughening mechanisms through proven quantitative *** on the information extracted from the in-depth SEM/TEM investigation,we outlined schematic models for understating the reinforcing ability as well as toughening mechanisms in the hybrid nanocomposites and meticulously *** hot-pressed hybrid nanocomposites owning high toughness and hardness may have applications in advanced armor technology.

关键词： Graphene Alumina Zirconia Toughness Hybrid nanocomposites

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Robust Half-Metallicity and Magnetic Properties of Cubic Perovskite CaFeO_(3)

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Chinese Physics Letters 2013年第4期30卷 192-196页

作者： Zahid Ali iftikhar ahmad Banaras Khan Imad Khan Materials Modeling Center Department of PhysicsUniversity of MalakandChakdaraDir(L)Pakistan Department of Physics Hazara UniversityMansehraPakistan

Theoretical studies of the cubic perovskite CaFeO3 are performed using the full potential linearized augmented plane-wave method with GGA+*** calculated structural parameters are consistent with the experimental *** tolerance factor reveals the cubic phase of the *** spin polarized electronic band structures and densities of states as well as the integer value of the magnetic moment of the unit cell(4μB)demonstrate that CaFeO_(3)is half *** in CaFeO_(3)is due to Fe^(+4)–O^(2)–Fe^(+4)superexchange *** robust properties of the compound show that with their compression up to a certain critical lattice constant,known as the robust transition lattice constant,an abrupt change in the electronic and magnetic properties occurs;the compounds lose their integer magnetic moment and become metallic.

关键词： integer cubic magnetic

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Time gap for temporal cloak based on spectral hole burning in atomic medium

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Chinese Physics B 2016年第8期25卷 175-180页

作者： Abdul Jabar M S Bakht Amin Bacha iftikhar ahmad Department of Physics University of Malakand

We demonstrate the possibility of creating a time gap in the slow light based on spectral hole burning in a fourlevel Doppler broadened sodium atomic system. A time gap is also observed between the slow and the fast light in the hole burning region and near the burnt hole region, respectively. A cloaking time gap is attained in microseconds and no distortion is observed in the transmitted pulse. The width of the time gap is observed to vary with the inverse Doppler effect in this system. Our results may provide a way to create multiple time gaps for a temporal cloak.

关键词： temporal cloak susceptibility slow and fast light spectral holes

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Geochemistry of metasedimentary rocks of the Sonakhan and Mahakoshal greenstone belts,Central India:Implications for paleoweathering,paleogeography and mechanisms of greenstone belt development

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Acta Geochimica 2022年第1期41卷 64-83页

作者： Hamidullah Wani M.E.A.Mondal iftikhar ahmad Department of Geology Government Degree College for Women PulwamaJammu and Kashmir 192301India Department of Geology Aligarh Muslim UniversityAligarhUttar Pradesh 202002India

A comparative study of the Precambrian Sonakhan(SGB)and Mahakoshal(MGB)greenstones belts of Central India has been undertaken to decipher their provenance,paleoweathering,paleogeography,and *** compared to the Upper Continental Crust(UCC),the MGB samples are enriched while the SGB samples are depleted in mafic elements indicating the presence of mafic rocks in the source of the *** is complemented by the Ni–Cr *** REE concentrations,LREE fractionated patterns and negative Eu anomalies of the MGB and SGB samples indicate derivation of sediments from a highly fractionated granitic *** MGB samples also contain the geochemical signature of mafic rocks,it is,therefore proposed that the MGB clastic load were derived from two sources(mafic+felsic)with arc *** is attested by Cr and Zr relationships,and LILE enrichment,and HFSE *** features suggest that the SGB developed as autochthonous while the MGB developed as an allochthonous *** chemical alteration indices such as chemical index of alteration(CIA),plagioclase index of alteration(PIA),and index of compositional variability for MGB samples indicate that they were dominantly derived as the first cycle(with minor recycled)sediments from bimodal sources(dominantly continental arcs)by intense chemical weathering as compared to the SGB samples,which were derived from felsic sources(dominantly cratonic rocks),and partly by recycling through a low chemical *** CIA and PIA values of the samples reveal a change in the climatic conditions from Late Archean to Late *** change is interpreted in terms of migration of the Indian plate from high latitudes in the Late Archean to lower latitudes during the Late *** is consistent with the paleomagnetic data that placed India in the configuration of 2.45 Ga Ur and 1.78 Ga Columbia supercontinents.

关键词： Central Indian Shield Sonakhan and Mahakoshal greenstone belts Paleoweathering and paleogeography Greenstone belt development

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Photodetachment of H^(-) near a Hard Spherical Surface

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Chinese Physics Letters 2012年第1期29卷 90-93页

作者： M.Haneef iftikhar ahmad A.Afaq A.Rahman Department of Physics Hazara UniversityMansehraPakistan Department of Physics University of MalakandChakdaraPakistan Centre of Excellence in Solid State Physics University of the PunjabQuid-e-Azam CampusLahore-54590Pakistan

The photodetachment of a hydrogen negative ion (H^(-)) near a hard spherical surface is investigated by using the theoretical imaging *** surface is oriented in such a fashion that the laser polarization direction is perpendicular to the principal axis of the spherical *** expressions are derived for the detachedelectron flux and photodetachment cross *** interference patterns are observed in the detachedelectron flux,while no visible oscillations are found in the photodetachment cross section.

关键词： visible polarization Strong

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