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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

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

Rock slope stability evaluation using kinematic and kinetic methods along the Kamyaran-Marivan road,west of Iran

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Journal of Mountain Science 2021年第3期18卷 779-793页

作者： Mohsen shariati Davood FEREIDOONI School of Earth Sciences Damghan UniversityDamghan 9823Iran

Interest in rock slope stability in mountainous regions has increased greatly in recent *** issue has become a topic of major interest for geoscientists and engineering professionals,as well as for private citizens and local administrators,in many parts of the *** paper evaluates the stability of seven rock slopes along the KamyaranMarivan tourist road,Kurdistan province,Iran,using various *** two main reasons for performing this research were to determine whether different methods of stability analysis provide the same results,and to determine how different factors such as the presence of water,tension cracks,and seismic forces affect the stability of these rock ***,field investigations were performed to obtain the engineering characteristics of the rock masses,discontinuities,and intact rocks of the ***,laboratory tests were carried out on rock samples obtained from the slopes,to determine the engineering properties of the intact *** for each rock slope,the contour diagram of discontinuities and slope face was drawn in the Dips v.5.1 software environment,and the failure mechanism was determined based on the kinematic or stereographic ***,the factors of safety of the rock slopes were calculated using the limit equilibrium method,based on the failure mechanisms resulting from the kinematic *** accuracy of the results obtained by these two methods was investigated using SWedge v.4.0 *** results indicated that four rock slopes have a potential for plane,wedge,and toppling failure,and three others are ***,it was found that the stability of the studied rock slopes decreases greatly in the presence of water,tension cracks,and seismic forces.

关键词： Kamyaran-Marivan Road Rock slope Rock mass Discontinuity Stability analysis

Fischer–Tropsch synthesis using Co and Co-Ru bifunctional nanocatalyst supported on carbon nanotube prepared via chemical reduction method

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Journal of Energy Chemistry 2019年第1期28卷 9-22页

作者： Jafar shariati Ali Haghtalab Amir Mosayebi Department of Chemical Engineering Tarbiat Modares University Department of Chemical Engineering Tafresh University

We used a chemical reduction method to synthesize the catalysts of cobalt(Co) and cobalt-ruthenium(Co-Ru) bifunctional supported on carbon nanotubes(CNTs) for Fischer–Tropsch synthesis(FTS) in a fixedbed reactor. These Co-Ru/CNTs catalysts were synthesized with various weight proportions of Ru/Co(0.1 to 0.4 wt%) with keeping a fixed amount of cobalt(10 wt%). Moreover, for comparison purpose, CNTs supported Co-and Co(Ru)-based catalysts at same loading as the above catalysts were prepared through impregnation method. We characterize the present catalysts through the various techniques such as Energy–dispersive X-ray(EDX), Transmission Electron Microscopy(TEM), Brunauer–Emmett–Teller(BET),Hydrogen-Temperature-Programmed Reduction(H_2-TPR), Hydrogen-Temperature-Programmed Desorption(H_2-TPD) and O_2 titration. Thus using the chemical reduction method, a narrow particle size distribution was obtained so that the small cobalt particles were confined inside the CNTs. The Co-based catalyst prepared by impregnation was compared with the Co-Ru catalysts at the same loading. The results demonstrated that the use of chemical reduction method led to decrease the average Co oxide cluster size to8.7 nm so that the reduction enhanced about 24% and stabilized an earlier time at the stream. Among the prepared catalysts, the results indicated that the Co-Ru/CNTs catalysts demonstrated high catalytic activity with the highest long-chain hydrocarbons(C_(5+)), selectivity up to 74.76%, which was higher than those we obtained by the Co-Ru/γ-Al_2O_3(61._20%), Co/CNTs(43.68%) and Co/γ-Al_2O_3(37.69%). At the same time, comparing with those catalyst synthesized by impregnation, the use of chemical reduction led to enhancement of the C_(5+) selectivity from 59.30% to 68.83% and increment in FTS rate about 11% for the Co-Ru/CNTs catalyst.

关键词： Cobalt-ruthenium Carbon nanotubes Fischer-Tropsch synthesis Catalyst nanoparticles Chemical reduction method

Theoretical description of electron-phonon Fock space for gapless and gapped nanowires

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Chinese Physics B 2017年第3期26卷 404-409页

作者： Ashrafalsadat shariati Hassan Rabani Mohammad Mardaani Department of Physics Faculty of Science Shahrekord University P. O. Box 115 Shahrekord Iran Nanotechnology Research Center Shahrekord University *** Shahrekord Iran

We study the effect of electron-phonon （e-ph） interaction on the elastic and inelastic electronic transport of a nanowire connected to two simple rigid leads within the tight-binding and harmonic approximations. The model is constructed using Green＇s function and multi-channel techniques, taking into account the local and nonlocal e-ph interactions. Then, we examine the model for the gapless （simple chain） and gapped （PA-like nanowire） systems. The results show that the tunneling conductance is improved by the e-ph interaction in both local and nonlocal regimes, while for the resonance conductance, the coherent part mainly decreases and the incoherent part increases. At the corresponding energies which depend on the phonon frequency, two dips in the elastic and two peaks in the inelastic conductance spectra appear. The reason is the absorption of the phonon by the electron in transition into inelastic channels.

关键词： Theoretical description of electron phonon Fock space for gapless and gapped nanowires

Linear and Nonlinear Formulation of Phase Field Model with Generalized Polynomial Degradation Functions for Brittle Fractures

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Acta Mechanica Solida Sinica 2024年第5期37卷 643-661页

作者： ala Tabiei Li Meng Department of Mechanical and Materials Engineering University of CincinnatiCincinnatiOH45221-0070USA

The classical phase field model has wide applications for brittle materials,but nonlinearity and inelasticity are found in its stress-strain *** degradation function in the classical phase field model makes it a linear formulation of phase field and computationally attractive,but stiffness reduction happens even at low *** this paper,generalized polynomial degradation functions are investigated to solve this *** first derivative of degradation function at zero phase is added as an extra constraint,which renders higher-order polynomial degradation function and nonlinear formulation of phase *** with other degradation functions(like algebraic fraction function,exponential function,and trigonometric function),this polynomial degradation function enables phase in[0,1](should still avoid the first derivative of degradation function at zero phase to be 0),so there is noconvergence *** good and meaningful finding is that,under the same fracture strength,the proposed phase field model has a larger length scale,which means larger element size and better computational *** proposed phase field model is implemented in LS-DYNA user-defined element and user-defined material and solved by the Newton-Raphson method.A tensile test shows that the first derivative of degradation function at zero phase does impact stress-strain *** I,mode II,and mixed-mode examples show the feasibility of the proposed phase field model in simulating brittle fracture.

关键词： Nonlinear formulation Generalized polynomial degradation function Brittle materials Stress-strain curve convergence

DNA Sequence Analysis for Brain Disorder Using Deep Learning and Secure Storage

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Computers, Materials & Continua 2022年第6期71卷 5949-5962页

作者： ala Saleh Alluhaidan Departmemt of Information Systems College of Computer and Information SciencePrincess Nourah Bint Abdulrahman UniversityRiyadh 11671Saudi Arabia

Analysis of brain disorder in the neuroimaging of Magnetic Resonance Imaging(MRI),Positron Emission Tomography(PET),and Computed Tomography(CT)needs to understand the functionalities of the brain and it has been performed using *** learning algorithms have also been applied in genomics data *** brain disorder diseases of Alzheimer,Schizophrenia,and Parkinson are analyzed in this *** main issue in the traditional algorithm is the improper detection of disorders in the neuroimaging *** paper presents a deep learning algorithm for the classification of brain disorder using Deep Belief Network(DBN)and securely storing the image using a Deoxyribonucleic Acid(DNA)Sequence-based Joint Photographic Experts Group(JPEG)Zig Zag Encryption Algorithm(DBNJZZ).In this work,DBNJZZ implements an efficient and effective prediction model for disorders using the open-access datasets of Alzheimer’s Disease Neuroimaging Initiative(Adni),the Center for Biomedical Research Excellence(Cobre),the Open Access Series of Imaging Studies(Oasis),the Function Biomedical Informatics Research Network(Fbirn),a Parkinson’s dataset of 55 patients and 23 subjects with Parkinson’s syndromes(Ntua),and the Parkinson’s Progression Markers Initiative(Ppmi).This algorithm is implemented and tested using performance metric measures of accuracy,Root Mean Square Error(RMSE),Mean Absolute Error(MAE),and Mean Absolute Percentage Error(MAPE).DBNJZZ gives better performance with an accuracy of 99.21%and also surpasses previous methods on other measures.

关键词： DBN Zig zag deep learning MAPE RMSE DNA genomics

Performance Comparison of Two Newly Developed Bimetallic(X-Mo/Al2O3, X=Fe or Co) Catalysts for Reverse Water Gas Shift Reaction

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China Petroleum Processing & Petrochemical Technology 2016年第1期18卷 51-58页

作者： Abolfazl Gharibi Kharaji Ahmad shariati University of lsfahan Isfahan Iran Petroleum University of Technology Ahwaz Iran

The performance of the two newly developed bimetallic catalysts based on the precursor, Mo/Al_2O_3, was compared for reverse water gas shift(RWGS) reaction. The structures of the precursor and the catalysts were studied using X-ray diffraction(XRD), Brunauer–Emmett–Teller(BET) analysis, inductively coupled plasma-atomic emission spectrometry(ICP-AES), CO chemisorption, temperature programmed reduction of hydrogen(H_2-TPR) and scanning electron microscopy(SEM) techniques. The activity of Fe-Mo and Co-Mo catalysts was compared in a fixed bed reactor at different temperatures. It is shown that the Co-Mo catalyst has higher CO_2 conversion at all temperature level. The time-on-stream(TOS) analysis of the activity of catalysts for the RWGS reaction was carried out over a continuous period of 60h for both catalysts. The Fe-Mo/Al_2O_3 catalyst exhibits good stability within a period of 60h, however, the Co-Mo/Al_2O_3 is gradually deactivated after 50h of reaction time. Existence of(Fe_2(MoO4_))_3 phase in Fe-Mo/Al_2O_3 catalyst makes this catalyst more stable for RWGS reaction.

关键词： RWGS reaction bimetallic catalysts activity stability

Microtechnology-based methods for organoid models

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Microsystems & Nanoengineering 2020年第1期6卷 381-393页

作者： Vanessa Velasco S.Ali shariati Rahim Esfandyarpour Biochemistry Department Stanford UniversityPalo AltoCAUSA Department of Biomolecular Engineering Institute for the Biology of Stem CellsUniversity of CaliforniaSanta CruzCAUSA Department of Electrical Engineering University of CaliforniaIrvineCAUSA Department of Biomedical Engineering University of California IrvineIrvineCAUSA Henry Samueli School of Engineering University of CaliforniaIrvineCAUSA

Innovations in biomaterials and stem cell technology have allowed for the emergence of novel three-dimensional(3D)tissue-like structures known as organoids and *** a result,compared to conventional 2D cell culture and animal models,these complex 3D structures have improved the accuracy and facilitated in vitro investigations of human diseases,human development,and personalized medical *** to the rapid progress of this field,numerous spheroid and organoid production methodologies have been ***,many of the current spheroid and organoid production techniques are limited by complexity,throughput,and *** and microscale platforms(e.g.,microfluidics and microprinting)have shown promise to address some of the current limitations in both organoid and spheroid *** and microfluidic devices have been shown to improve nutrient delivery and exchange and have allowed for the arrayed production of size-controlled culture areas that yield more uniform organoids and spheroids for a higher throughput at a lower *** this review,we discuss the most recent production methods,challenges currently faced in organoid and spheroid production,and microfabricated and microfluidic applications for improving spheroid and organoid ***,we focus on how microfabrication methods and devices such as lithography,microcontact printing,and microfluidic delivery systems can advance organoid and spheroid applications in medicine.

关键词： printing culture biomaterials