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Kinematic analysis of flexible bipedal robotic systems

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Applied mathematics and mechanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FAZEL A.m.SHAFEI S.r.NEKOO Department of mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de Sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

robust H_∞ control for uncertain markovian jump systems with mixed delays

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Chinese Physics B 2016年第7期25卷 108-113页

作者： r Saravanakumar m Syed Ali Department of mathematics Thiruvalluvar University

We scrutinize the problem of robust H∞control for a class of markovian jump uncertain systems with interval timevarying and distributed delays. The markovian jumping parameters are modeled as a continuous-time finite-state markov chain. The main aim is to design a delay-dependent robust H∞control synthesis which ensures the mean-square asymptotic stability of the equilibrium point. By constructing a suitable Lyapunov–Krasovskii functional（LKF）, sufficient conditions for delay-dependent robust H∞control criteria are obtained in terms of linear matrix inequalities（LmIs）. The advantage of the proposed method is illustrated by numerical examples. The results are also compared with the existing results to show the less conservativeness.

关键词： linear matrix inequality Lyapunov method markovian jumping parameters robust H∞ control

Effect of substrate temperature on the morphological,structural,and optical properties of rF sputtered Ge(1-x)Snx films on Si substrate

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Chinese Physics B 2017年第5期26卷 313-318页

作者： H mahmodi m r Hashim Nano-Optoelectronics research Laboratory School of Physics Universiti Sains Malaysia 11800 USM Pulau Penang Malaysia Institute of Nano Optoelectronics research and Technology (INOr) Universiti Sains Malaysia 11800 USM Pulau Penang Malaysia

In this study, Ge（1-x）Snx alloy films are co-sputtered on Si（100） substrates using rF magnetron sputtering at different substrate temperatures. Scanning electron micrographs, atomic force microscopy（AFm）, raman spectroscopy, and x-ray photoemission spectroscopy（XPS） are conducted to investigate the effect of substrate temperature on the structural and optical properties of grown Ge Sn alloy films. AFm results show that rmS surface roughness of the films increases from 1.02 to 2.30 nm when raising the substrate temperature. This increase could be due to Sn surface segregation that occurs when raising the substrate temperature. raman spectra exhibits the lowest FWHm value and highest phonon intensity for a film sputtered at 140℃. The spectra show that decreasing the deposition temperature to 140℃ improves the crystalline quality of the alloy films and increases nanocrystalline phase formation. The results of raman spectra and XPS confirm Ge–Sn bond formation. The optoelectronic characteristics of fabricated metal-semiconductor-metal photodetectors on sputtered samples at room temperature（rT） and 140℃ are studied in the dark and under illumination. The sample sputtered at 140℃ performs better than the rT sputtered sample.

关键词： sputtering magnetron illumination crystalline raising roughness optoelectronic phonon segregation FWHm

Search for microglia-specific peptides:advances in the discovery toolbox

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Neural regeneration research 2025年第2期20卷 471-472页

作者： Ivan Sarabia Kyle m.Koss Department of Surgery University of ArizonaTucsonAZUSA

Uncontrolled and chronic inflammatory states in the central nervous system(CNS)are the hallmark of neurodegenerative pathology and every injury or stroke-related *** key mediators of these neuroinflammatory states are glial cells known as microglia,the resident immune cell at the core of the inflammatory event,and astroglia,which encapsulate inflammatory insults in proteoglycan-rich scar *** gliotic scar blocks significant portions of healthy axonal networking,preventing *** most neuroinflammation is exclusively based on the responses of said microglia,their phenotypes are suggested to follow those of macrophages;m1 and m2 are opposites of pro-and ***,microglial phenotypes have been identified to be on an inflammatory spectrum encompassing developmental,homeostatic,and reparative behaviors as opposed to their ability to affect devastating cell death cascades and scar tissue formation.

关键词： inflammation pathology death

On the Characterizability of the Automorphism Groups of Sporadic Simple Groups by Their Element Orders

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Acta mathematica Sinica,English Series 2004年第4期20卷 653-662页

作者： A.r.mOGHADDAmFAr A.r.ZOKAYI m.r.DArAFSHEH Department of mathematics Faculty of ScienceK.N.Toosi University of TechnologyP.O.Box 16315-1618TehranIran Department of mathematics and Computer Sciences Faculty of ScienceUniversity of TehranTehranIran

For G a finite group,π_e(G)denotes the set of orders of elements in *** Ω is a subset of the set of natural numbers,h(Ω)stands for the number of isomorphism classes of finite groups with the same set Ω of element *** say that G is k-distinguishable if h(π_(G))=krwise G is called ***,a 1-distinguishable group is called a characterizable *** is shown that if m is a sporadic simple group different from m_(12),m_(22),J_2,He,Suz,m^cL and O'N, then Aut(m)is charaeterizable by its dement *** is also proved that if m is isomorphic to m_(12),m_(22),He,Suz or O'N,then h(π_e(Aut(m)))∈{1,∞}.

关键词： Automorphism group Element orders Prime graph Sporadic simple groups

A rECOGNITION OF SImPLE GrOUPS PSL(3,q) BY THEIr ELEmENT OrDErS

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Acta mathematica Scientia 2004年第1期24卷 45-51页

作者： m.r.Darafsheh A.r.moghaddamfar A.r.Zokayi Department of mathematics and Computer Sciences Faculty of Science University of Tehran Tehran IranDepartment of Mathematics K. N. T University of TechnologyP.O. Boz 16315-1618 Tehuan IranDepartment of Mathematics K. N. T University of TechnologyP.O. Boz 16315-1618 Tehuan Iran

For any group G, denote byπe(G) the set of orders of elements in G. Given a finite group G, let h(πe (G)) be the number of isomorphism classes of finite groups with the same set πe(G) of element orders. A group G is called k-recognizable if h(πe(G)) = k rwise G is called non-recognizable. Also a 1-recognizable group is called a recognizable (or characterizable) group. In this paper the authors show that the simple groups PSL(3,q), where 3 mod 5) and (6, (q-1)/2) = 1, are recognizable.

关键词： Element order prime graph projective special linear group

Effects of viscoelasticity on the stability and bifurcations of nonlinear energy sinks

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Applied mathematics and mechanics(English Edition) 2023年第1期44卷 141-158页

作者： A.mOSLEmI m.r.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran ***Iran

Due to the increasing use of passive absorbers to control unwanted vibrations,many studies have been done on energy absorbers ideally,but the lack of studies of real environmental conditions on these absorbers is *** present work investigates the effect of viscoelasticity on the stability and bifurcations of a system attached to a nonlinear energy sink(NES).In this paper,the Burgers model is assumed for the viscoelasticity in an NES,and a linear oscillator system is considered for investigating the instabilities and *** equations of motion of the coupled system are solved by using the harmonic balance and pseudo-arc-length continuation *** results show that the viscoelasticity affects the frequency intervals of the Hopf and saddle-node branches,and by increasing the stiffness parameters of the viscoelasticity,the conditions of these branches occur in larger ranges of the external force amplitudes,and also reduce the frequency range of the *** addition,increasing the viscoelastic damping parameter has the potential to completely eliminate the instability of the system and gradually reduce the amplitude of the jump phenomenon.

关键词： viscoelasticity Burgers model nonlinear energy sink(NES) saddle-node bifurcation Hopf bifurcation

Pile foundation in alternate layered liquefiable and non-liquefiable soil deposits subjected to earthquake loading

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Earthquake Engineering and Engineering Vibration 2024年第2期23卷 359-376页

作者： Praveen Huded m Suresh r Dash LEA Associates South East Asia Pvt.Ltd. New Delhi 110044India Indian Institute of Technology Bhubaneswar Khurda 752050India

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone *** foundations have experienced failures in past earthquakes due to *** on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil ***,in natural occurrence,it may occur in alternative layers of liquefiable and non-liquefiable ***,the experimental and/or numerical studies on the layered effect on pile foundations have not been widely addressed in the *** of the design codes across the world do not explicitly mention the effect of sandwiched non-liquefiable soil layers on the pile *** the present study,the behavior of an end-bearing pile in layered liquefiable and non-liquefiable soil deposit is studied *** study found that the kinematic bending moment is higher and governs the design when the effect of the sandwiched non-liquefied layer is considered in the analysis as opposed to when its effect is ***,ignoring the effect of the sandwiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.

关键词： pile foundation liquefaction alternately layered soil fixity effect layered effect

SBL-JP-0004: A promising dual inhibitor of JAK2 and PI3KCD against gastric cancer

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Oncology research 2025年第1期33卷 235-243页

作者： Hassan m Otifi Department of Pathology College of Medicine King Khalid University Abha 62521 Saudi Arabia.

Background:Gastric cancer (GC) remains a global health burden and is often characterized by heterogeneous molecular profiles and resistance to conventional therapies. The phosphoinositide 3-kinase and PI3K and Janus kinase (JAK) signal transducer and activator of transcription (JAK-STAT) pathways play pivotal roles in GC progression, making them attractive targets for therapeutic interventions.methods:This study applied a computational and molecular dynamics simulation approach to identify and characterize SBL-JP-0004 as a potential dual inhibitor of JAK2 and PI3KCD kinases. KATOIII and SNU-5 GC cells were used for evaluation.results:SBL-JP-0004 exhibited a robust binding affinity for JAK2 and PI3KCD kinases, as evidenced by molecular docking scores and molecular dynamics simulations. Binding interactions and Gibbs binding free energy estimates confirmed stable and favorable interactions with target proteins. SBL-JP-0004 displayed an half-maximal inhibitory concentration (IC) value of 118.9 nm against JAK2 kinase and 200.9 nm against PI3KCD enzymes. SBL-JP-0004 exhibited potent inhibition of cell proliferation in KATOIII and SNU-5 cells, with half-maximal growth inhibitory concentration (GI) values of 250.8 and 516.3 nm, respectively. A significant elevation in the early phase apoptosis (28.53% in KATOIII cells and 26.85% in SNU-5 cells) and late phase apoptosis (17.37% in KATOIII cells and 10.05% in SNU-5 cells) were observed with SBL-JP-0004 treatment compared to 2.1% and 2.83% in their respective controls.Conclusion:The results highlight SBL-JP-0004 as a promising dual inhibitor targeting JAK2 and PI3KCD kinases for treating GC and warrant further preclinical and clinical investigations to validate its utility in clinical settings.

关键词： Dual inhibition Gastric cancer (GC) JAK2 molecular docking molecular dynamics simulation PI3KCD SBL-JP-0004