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Non-Monotonic Lyapunov-krasovskii Functional Approach to Stability Analysis and Stabilization of Discrete Time-Delay Systems

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 752-763页

作者： Younes Solgi alireza Fatehi Ala Shariati Advanced Process Automation and Control Research Group Industrial Control Center of ExcellenceFaculty of Electrical EngineeringK.N.Toosi University of TechnologyTehran 16317-14191Iran IEEE

In this paper, a novel non-monotonic Lyapunov-krasovskii functional approach is proposed to deal with the stability analysis and stabilization problem of linear discrete time-delay systems. This technique is utilized to relax the monotonic requirement of the Lyapunov-krasovskii theorem. In this regard, the Lyapunov-krasovskii functional is allowed to increase in a few steps, while being forced to be overall decreasing. As a result, it relays on a larger class of Lyapunov-krasovskii functionals to provide stability of a state-delay system. To this end, using the non-monotonic Lyapunov-krasovskii theorem, new sufficient conditions are derived regarding linear matrix inequalities(LMIs)to study the global asymptotic stability of state-delay ***, new stabilization conditions are also proposed for time-delay systems in this article. Both simulation and experimental results on a p H neutralizing process are provided to demonstrate the efficacy of the proposed method.

关键词： Linear matrix inequality(LMI) non-monotonic Lyapunov-krasovskii functional(NMLkF) pH neutralization plant stabilization state-delay system time-delay system

Challenges of Artificial Intelligence in Space Medicine

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Space(Science & Technology) 2022年第1期2022卷 363-369页

作者： Ethan Waisberg Joshua Ong Phani Paladugu Sharif Amit kamran Nasif Zaman Andrew G.Lee alireza Tavakkoli University College Dublin School of Medicine BelfieldDublinIreland Michigan Medicine University of MichiganAnn ArborMichiganUSA Brigham and Women’s Hospital Harvard Medical SchoolBostonMassachusettsUSA Human-Machine Perception Laboratory Department of Computer Science and EngineeringUniversity of NevadaRenoRenoNevadaUSA Center for Space Medicine Baylor College of MedicineHoustonTexasUSA Department of Ophthalmology Blanton Eye InstituteHouston Methodist HospitalHoustonTexasUSA

The human body undergoes many changes during long-duration spaceflight including musculoskeletal,visual,and behavioral *** of these microgravity-induced effects serve as potential barriers to future exploration *** advent of artificial intelligence(AI)in medicine has progressed rapidly and has many promising applications for maintaining and monitoring astronaut health during ***,the austere environment and unique nature of spaceflight present with challenges in successfully training and deploying successful systems for upholding astronaut health and mission *** this article,the dynamic barriers facing AI development in space medicine are *** diverse challenges range from limited astronaut data for algorithm training to ethical/legal considerations in deploying automated diagnostic systems in the setting of the medically limited space *** to address these challenges is then discussed and future directions for this emerging field of research.

关键词： legal directions barriers

3D-printed bioactive scaffolds from nanosilicates and PEOT/PBT for bone tissue engineering

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Regenerative Biomaterials 2019年第1期6卷 29-37页

作者： James k.Carrow Andrea Di Luca alireza Dolatshahi-Pirouz Lorenzo Moroni Akhilesh k.Gaharwar Department of Biomedical Engineering Texas A&M UniversityCollege StationTX 77843USA Tissue Regeneration Department MIRA Institute for Biomedical Technology and Technical MedicineUniversity of TwenteEnschedeThe Netherlands DTU Nanotech Center for Intestinal Absorption and Transport of BiopharmaceuticalsTechnical University of Denmark2800 KgsLyngbyDenmark Department of Complex Tissue Regeneration MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht UniversityUniversiteitsingel 406229ER MaastrichtThe Netherlands Department of Materials Science Texas A&M UniversityCollege StationTX 77843USA Center for Remote Health Technologies and Systems Texas A&M UniversityCollege StationTX 77843USA

Additive manufacturing(AM)has shown promise in designing 3D scaffold for regenerative ***,many synthetic biomaterials used for AM are ***,we report synthesis of bioactive nanocomposites from a poly(ethylene oxide terephthalate)(PEOT)/poly(butylene terephthalate)(PBT)(PEOT/PBT)copolymer and 2D nanosilicates for fabricating 3D scaffolds for bone tissue ***/PBT have been shown to support calcification and bone bonding ability in vivo,while 2D nanosilicates induce osteogenic differentiation of human mesenchymal stem cells(hMSCs)in absence of osteoinductive *** effect of nanosilicates addition to PEOT/PBT on structural,mechanical and biological properties is ***,the addition of nanosilicate to PEOT/PBT improves the stability of nanocomposites in physiological conditions,as nanosilicate suppressed the degradation rate of ***,no significant increase in the mechanical stiffness of scaffold due to the addition of nanosilicates is *** addition of nanosilicates to PEOT/PBT improves the bioactive properties of AM nanocomposites as demonstrated in *** readily proliferated on the scaffolds containing nanosilicates and resulted in significant upregulation of osteo-related proteins and production of mineralized *** synergistic ability of nanosilicates and PEOT/PBT can be utilized for designing bioactive scaffolds for bone tissue engineering.

关键词： 3D printing nanocomposites two dimensional(2D)nanoparticles copolymer tissue engineering

Strength evolution and deformation behaviour of cemented paste backfill at early ages： Effect of curing stress, filling strategy and drainage

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International Journal of Mining Science and Technology 2016年第5期26卷 809-817页

作者： Ghirian alireza Fall Mamadou Department of Civil Engineering University of Ottawa 161 Louis Pasteur Ottawa K1N 6N5 ON Canada

In this study, a pressure cell apparatus is developed to investigate the early age evolution of the strength and deformation behaviour of cemented paste backfill(CPB) when subjected to various loading conditions under different curing scenarios. The different curing scenarios that are simulated include:(1)drained and undrained conditions,(2) different filling rates,(3) different filling sequences, and(4) different curing stresses. The findings show that drainage, curing stress, curing time and filling rate influence the mechanical and deformation behaviours of CPB materials. The coupled effects of consolidation, drainage and suction contribute to the strength development of drained CPB subjected to curing stress. On the other hand, particle rearrangement caused by the applied pressure and suction development due to self-desiccation plays a significant role in the strength gain of undrained CPB cured under ***, curing stress induces slightly faster rate of cement hydration, which can contribute to strength acquisition.

关键词： Cemented paste backfill Tailings Pore pressure Curing under stress Plug fill Cement

Characterization of Operators on the Dual of Hypergroups which Commute with Translations and Convolutions

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Acta Mathematica Sinica,English Series 2004年第2期20卷 201-208页

作者： Ali Ghaffari alireza Medghalchi Department of Mathematics Semnan UniversityP.O.Box 35195-363SemnanIran Department of Mathematics Teacher Training UniversityTehranIran.

For a locally compact group G, L 1(G) is its group algebra and L ∞(G) is the dual of L 1(G). Lau has studied the bounded linear operators T : L ∞(G) → L ∞(G) which commute with convolutions and translations. For a subspace H of L ∞(G), we know that M(L ∞(G),H), the Banach algebra of all bounded linear operators on L ∞(G) into H which commute with convolutions, has been studied by Pym and Lau. In this paper, we generalize these problems to L(k)*, the dual of a hypergroup algebra L(k) in a very general setting, i. e. we do not assume that k admits a Haar measure. It should be noted that these algebras include not only the group algebra L 1(G) but also most of the semigroup algebras. Compact hypergroups have a Haar measure, however, in general it is not known that every hypergroup has a Haar measure. The lack of the Haar measure and involution presents many difficulties; however, we succeed in getting some interesting results.

关键词： Hypergroup algebras Group algebras Operators Translations Convolutions Invariant

Fabrication method and microstructural characteristics of coal-tar-pitchbased 2D carbon/carbon composites

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 210-216页

作者： Mohammad Esmaeeli Hamed khosravi alireza Mirhabibi School of Metallurgy and Materials Engineering Iran University of Science and Technology Faculty of Materials Science and Engineering K. N. Toosi University of Technology

The lignin-cellulosic texture of wood was used to produce two-dimensional （2D） carbon/carbon （C/C） composites using coal tar pitch. Ash content tests were conducted to select two samples among the different kinds of woods present in lran, including walnut, white poplar, cherry, willow, buttonwood, apricots, berry, and blue wood. Walnut and white poplar with ash contents of 1.994wt% and 0.35 lwt%, respectively, were selected. The behavior of these woods during pyrolysis was investigated by differential thermal analysis （DTA） and thermo gravimetric （TG） analysis. The bulk density and open porosity were measured after carbonization and densification. The mierostruc- tural characteristics of samples were investigated by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, and Fourier-transform infrared （FT-IR） spectroscopy. The results indicate that the density of both the walnut and white poplar is increased, and the open porosity is decreased with the increasing number of carbonization cycles. The XRD patterns of the wood charcoal change gradually with increasing py- rolysis temperature, possibly as a result of the ultra-structural changes in the charcoal or the presence of carbonized coal tar pitch in the composite＇s body.

关键词： carbon/carbon composites microstructure porosity density densification carbonization

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细砂中钢带-填土废塑料瓶抗拔性能试验研究

岩土力学 2022年第11期43卷 3073-3082页

作者： alireza BEYRANVAND SEYED HAMID LAJEVARDI MAHMOUD GHAZAVI SEYED MOHAMMAD MIRHOSSEINI 技术和职业大学(TVU)土木工程系德黑兰伊朗伊斯兰阿扎德大学土木工程系阿扎德分校阿拉克伊朗 k.N.图斯大学土木工程系德黑兰伊朗

研究利用填土废塑料瓶作为横向构件附在加筋土挡墙(MSEWs)中钢带上可行性。配筋中的横向构件对增加抗拔力有重要影响。该加筋系统是由作为纵向构件的钢带和作为横向构件的填土废塑料瓶组成。为更好地研究以填土废塑料瓶作为横向构件对... 详细信息

研究利用填土废塑料瓶作为横向构件附在加筋土挡墙(MSEWs)中钢带上可行性。配筋中的横向构件对增加抗拔力有重要影响。该加筋系统是由作为纵向构件的钢带和作为横向构件的填土废塑料瓶组成。为更好地研究以填土废塑料瓶作为横向构件对抗拔性能的影响,对一条独立的钢带和分别带有1~7个瓶子的钢带进行了拉拔试验。在不同的法向应力下进行了超过18次的实验室大型拉拔试验(例如拉拔箱尺寸为长1.2 m、宽0.6 m、高1.0 m)来评估新提出的加固元件的性能。试验结果表明,在扁钢带上建立三维空间对提高抗拔阻力影响很大。提高抗拔阻力最有效的方法是在距离S与直径D之比为3的钢带上加入4个横向构件,其平均抗拔阻力约为单独钢带的5倍。有横向构件和无横向构件钢带的极限抗拔阻力随竖向应力的增大而增大。

关键词：抗拔阻力横向构件废塑料瓶加筋土抗拔试验

Novel Non-monotonic Lyapunov-krasovskii Based Stability Analysis and Stabilization of Discrete State-delay System

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International Journal of Automation and computing 2020年第5期17卷 713-732页

作者： Younes Solgi alireza Fatehi Ala Shariati APAC Research Group Industrial Control Center of ExcellenceFaculty of Electrical EngineeringK.N.Toosi University of TechnologyTehran ***Iran

This paper proposes a novel less-conservative non-monotonic Lyapunov-krasovskii stability approach for stability analysis of discrete time-delay *** this method,monotonically decreasing requirements of the Lyapunov-krasovskii method are replaced with non-monotonic *** Lyapunov-krasovskii functional is allowed to increase in some steps,but the overall trend should be *** model of practical systems used for stability analysis usually contain ***,firstly a non-monotonic stability condition is derived for certain discrete time-delay systems,then robust non-monotonic stability conditions are proposed for uncertain ***,a novel stabilization algorithm is derived based on the introduced non-monotonic stability *** Lyapunov-krasovskii functional and the controller are obtained by solving a set of linear matrix inequalities(LMI)or iterative LMI based nonlinear *** proposed theorems are first evaluated by some numerical examples,and then by simulation and implementation on the pH neutralizing process plant.

关键词： Lyapunov-krasovskii functional discrete state-delay systems non-monotonic Lyapunov function robust stability stabilization

Surface treatment of titanium dental implant with H2O2 solution

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1281-1286页

作者： Mohammad khodaei kamran Amini alireza Valanezhad Ikuya Watanabe Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayegan ***Iran Center for Advanced Engineering Research Majlesi BranchIslamic Azad UniversityIsfahan 196151194Iran Department of Dental and Biomedical Materials Science Graduate School of Biomedical SciencesNagasaki University1-7-1 SakamotoNagasaki 852-8588Japan

The surface treatment is important for titanium and its alloys as promising candidates for dental implantation due to their bioinert *** surface samples were modified using H2O2 solution at different times up to 72 h to boost their *** to the results of the field emission scanning electron microscopy test,some nanostructures are formed on the surface of treated titanium samples and increased in size by increasing the time of treatment up to 24 *** 24 h of application,the sharpness of nanostructures decreased and the micro-cracks and discontinuity in the coating surface *** results of the X-ray diffraction study and Raman spectroscopy revealed that anatase(TiO2)was formed on the surface of treated titanium *** peak intensity of Raman spectroscopy increased with an improvement in treatment time of up to 24 h and then decreased due to the discontinuity of the *** wettability and ability to form apatite were reached at 6 h of *** is clear that the treatment time has a significant effect on the surface treatment of titanium using the H2O2 solution.

关键词： titanium implant surface treatment hydrogen peroxide anatase dental implant